ALBERT

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Jingqi Tan, Jianjian Wei, Tao Jin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Onset and damping processes that characterize the transition of a thermoacoustic engine between the stationary and periodic oscillating states have attracted much research effort. In this work, the onset and damping characteristics of a closed two-phase thermoacoustic engine are investigated, where a regenerator is inserted between the cold and hot heat exchangers to reduce the irreversible loss caused by heat transfer. Additionally, a branch resonator, which consists of a load tube and a gas reservoir, is introduced to form the closed system and to adjust the acoustic field. A lumped parameter model is proposed to quantitatively analyze the performance of the thermoacoustic engine. Upon optimization, an onset temperature difference as low as 8.2 °C can be achieved in the experiments with R134a as the working fluid, which is the lowest one ever reported in the literatures. Besides, hysteresis phenomenon is found during the onset and damping processes. The present work aims to provide better understanding of the onset and damping behaviors of a two-phase thermoacoustic engine.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Bin Zou, Yiqiang Jiang, Yang Yao, Hongxing Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Since various optical factors, including sunshape and optical errors, coexist in practice, their coupling effects on the PTC’s optical performance deserve in-depth explorations. Previous studies mainly focused on individual effects of several typical optical errors or simple description of optical errors using a unified Gaussian model. Thus, this study is committed to investigating the coupling effects of multiple optical factors on the PTC’s optical performance based on the theoretically individual characterization of each optical factor. The Monte Carlo Rays Tracing method was adopted, and the effective sunshape model was established for sampling of incident rays by convolving the incident sunshape model with the specularity error model. It is revealed that larger circumsolar ratio and specularity error produced more uniform heat flux distribution on the absorber. The advantage of high optical quality reflectors in improving optical efficiency was more outstanding in clearer weather. As circumsolar ratio was more than 0.2, improving specular quality to very high degree (〈3 mrad) reduced instead the optical efficiency. When tracking error and slope error were maintained respectively less than 4 mrad and 2 mrad, the weakening of optical efficiency was limited. The optical efficiency was more sensitive to slope error than to tracking error. The offset direction along positive Y-axis caused at maximum 2.19 times increase in heat flux density than that without optical errors, which causes threat of overheating to the absorber. When alignment error and tracking error were in the opposite direction, the optical loss could be compensated, whereas that in the same direction enlarged the optical loss. The slope error weakened the compensation effect and aggravated the weakening effect.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Jiaxu Wang, Xuefeng Liu, Siwei Chen, Hanghang Jiang, Guanyu Fang, Wenjing Chen, Shiming Deng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The current work study the heat dissipation characteristics and airflow distribution in a power cabin. By simplifying the cable structure, a 1:5 reduced-scale model was constructed based on the Archimedes number. Computational fluid dynamics (CFD) simulations were applied to the prototype power cabin. The 3D steady-state Reynolds average Navier-Stokes (RANS) equation is used to solve the ventilation flow, where the turbulence model is realizable k–ε. The CFD simulation of the prototype has been verified by the reduced-scale model. On this basis, several conclusions were drawn. The airflow distribution in the power cabin and cable arrangement cause a difference in the temperature distribution between the cables. The strong turbulence at the air inlet causes a significant temperature drop. The mechanical fan can effectively cool the cable to a certain extent, but cable temperature control should take into account the effects of ampacity and ventilation, as well as cable location.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Wenwu Zhou, Lin Yuan, Xin Wen, Yingzheng Liu, Di Peng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study explored and examined the piezoelectric (PE) jet: an active cooling concept that can be actuated in demand, which had an oscillating flow and extremely low power consumption. The heat transfer and flow characteristics of the PE jet were quantified at various Reynolds numbers (〈em〉Re〈/em〉 = 5000, 10,000, 18,000) and spacings (〈em〉H〈/em〉/〈em〉D〈/em〉 = 4.5, 5.5, 6.5; corresponding gap 〈em〉G〈/em〉/〈em〉D〈/em〉 = 0.1, 1.1, 2.1). The temperature sensitive paint technique was used to study the heat transfer, and the particle image velocimetry technique was applied to resolve the flow characteristics and to further correlate the heat transfer results. Measured results show that the impingement cooling of the PE jet increased as the 〈em〉Re〈/em〉 increased and as the 〈em〉H〈/em〉/〈em〉D〈/em〉 decreased. Compared with a circular jet, the PE jet exhibited a greatly improved heat transfer at 〈em〉H〈/em〉/〈em〉D〈/em〉 = 4.5 (i.e., 〈em〉G〈/em〉 = 0.1〈em〉D〈/em〉), with a maximum of 20% enhancement in area-averaged 〈em〉Nu〈/em〉. Due to the fan oscillation, the turbulent kinetic energy level in the PE jet was significantly higher than in the circular jet, which greatly promoted the heat transfer at a narrow gap. In general, the new PE jet can provide superior heat transfer performance at a small gap and a high Reynolds number.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Sarvenaz Abolghassem, Shiva Molaei, Shahrzad Javanshir〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, chitin (Ch) was extracted by an optimized method from cuttlebone of the Persian Gulf cuttlefish (Sepiidae, Cephalopoda). The extracted chitin was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) and thermal gravimetric analysis (TGA) which showed that the extracted chitin was in alpha form. The degree of N-acetylation (DA) and degree of substitution (DS) of α-chitin were calculated using titration method and FTIR spectroscopy and found to be 80–82% and 19.57 respectively. The α-Chitin was used as biomolecules for the preparation of nanostructured Ch/ZnO via a hydrothermal method. The obtained nanocomposite was characterized using FT-IR, XRD, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analysis. The antimicrobial aspect of Ch/ZnO nanocomposite was previously proposed. In this paper, attempt was made to add the catalytic feature to these traits. For this purpose, the nanostructured Ch/ZnO was used as reusable nanocatalyst in the green and efficient synthesis of Benzo[a]pyrano(2,3-c)phenazine derivatives thru a four components microwave aided domino reaction. Eco-friendly, easy work up and separation of the nanostructured catalyst are some of the highlighted features this protocol.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Zurel S. Costa, Cristiano T. Meneses, Bruno Castro, Fabiane S. Serpa, Elton Franceschi, Gustavo R. Borges, Cláudio Dariva, Giancarlo R. Salazar-Banda〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The formation of scales in the petroleum industry, such as those composed of calcium and barium sulfates, may reduce productivity since these sediments can partially or totally obstruct the pipes. The mitigation of these inorganic precipitates can be accomplished by using scale inhibitors or by non-intrusive physical technologies. Here, we investigated the influence of magnetic field on the incrustations of barium sulfate by analyzing the concentration of barium and sulfate ions, the solution flow rate, the capillary tube geometry, and the magnetic field intensity in a homemade experimental unit supported on the monitoring of the dynamic differential pressure. The results show that the saline concentration and the flow rate of the solutions and the geometry of the capillary tube have a significant influence on the dynamics of barium sulfate incrustation. The presence of the magnetic field tends to prolong the induction time of the barium sulfate precipitation. A semi-empirical model was used to describe the effect of the studied variables on the barium sulfate incrustation behavior. The X-ray diffraction data of the precipitated particles analyzed using the Rietveld method suggest that the use of the magnetic field favor the formation of more crystalline particles and with smaller crystallite size than those formed in the absence of a magnetic field. Optical and scanning electron microscopy measurements also corroborate with these findings. The results from this study suggest that magnetic fields can be of interest in practical crystallization processes of barium sulfate and successfully applied to decrease the speed of barium sulfate incrustation in pipelines.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Sanaz Tabasi, Hossein Yousefi, Younes Noorollahi, Mohamad Aramesh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, the performance of a photovoltaic panel integrated with a reflecting mirror is investigated. In this regard, the effects of panel and mirror tilt angles, and the mirror length on the system performance are modeled. The cell temperature rises have also been considered. Moreover, by a 3D model, the lighting and shading statuses are studied in detail, and all the possible conditions are presented and modeled. The resulting model can calculate the amount of incident solar energy on the panel and the generated electrical power in every moment during a year. This amount is dependent on the system configuration and capacity and its location. A 250-W photovoltaic panel and the city of Tehran have been considered the basics of calculations to assess the model results. By employing the genetic algorithm method, the optimum configuration has been found to have 69.084° and 0° tilt angles for the panel and the mirror, respectively, at the mirror length of 2 m. This configuration can generate 2.38 GJ (613.89 kWh) of electrical energy annually. It was also found that the optimum configuration had 0.024 GJ of annual energy losses due to the effects of cell temperature rise.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Su Min Hoi, An Liang Teh, Ean Hin Ooi, Irene Mei Leng Chew, Ji Jinn Foo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The flow across the plate-fin heat sink under the influence of 2D planar space-filling square fractal grid-induced turbulence at Reynolds number 〈em〉Re〈sub〉Dh〈/sub〉〈/em〉 of 2.0 × 10〈sup〉4〈/sup〉 is numerically characterized. Fractal thickness ratio 〈em〉t〈sub〉r〈/sub〉〈/em〉, plate-fin inter-fin distance 〈em〉δ〈/em〉 and grid-fin separation 〈em〉ℓ〈/em〉 are numerically explored and optimized via Response Surface Optimization (RSO) with the objective of maximizing the Nusselt number 〈em〉Nu〈/em〉. Results reveal that, thanks to highly interactive, small and comparable turbulence length scale 〈em〉L〈sub〉t〈/sub〉〈/em〉, strong turbulence intensity 〈em〉T〈sub〉u〈/sub〉〈/em〉 and high velocity adjacent to the fin surfaces, thermal dissipation of plate-fin heat sink enhances significantly. An optimum fractal grid and plate-fin geometrical combination having 〈em〉t〈sub〉r〈/sub〉〈/em〉 = 9.77, 〈em〉δ〈/em〉 = 0.005 m and 〈em〉ℓ〈/em〉 = 0.01 m is proposed. It delivers 〈em〉Nu〈/em〉 of 3661.0 which is 6.1% and 16.3% greater than the reference case and least favorable configuration, respectively. Sensitivity analysis discovered that 〈em〉δ〈/em〉 effectively dominates the thermal dissipation improvement while 〈em〉t〈sub〉r〈/sub〉〈/em〉 contributes the most on the pressure drop. Interestingly, fractal grid may not necessarily augmenting plate-fin forced convective heat transfer. Without proper-tuning the fluid flow structures within the fins may worsen the thermal dissipation instead of strengthening it. In short, the interaction between plate-fin heat sink and the fluid flow structures within the fins contributes greatly to heat transfer performance.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Mark Baldry, Victoria Timchenko, Chris Menictas〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Metal additive manufacturing technologies are increasingly being adopted for rapid prototyping and to build geometrically complex designs for thermal management. This paper develops and experimentally validates a numerical model to design a high performance, small-scale heat sink for use with a thermoelectric cooling cap. The design was constrained by a heat load of 2.15 W, and a target average base temperature of 45 °C as a compromise between avoiding burn injury and reducing heat dissipation requirements. Over successive numerical iterations, an optimal natural convection heat sink was developed with an estimated thermal resistance of 10.9  K·W〈sup〉−1〈/sup〉 and base temperature of 44.4 °C. This design featured an internal cavity in a tapered pin array, and was able to achieve a steady state base temperature that was 11.7 °C cooler than a conventional design, with 51% less surface area and significantly less material.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Nae-Hyun Kim, Cheol-Hwan Kim, Yousaf Shah, Wei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In a parallel flow heat exchanger, significant mal-distribution of flow occurs due to phase separation. In this study, various insert devices (perforated tube, perforated tube with perforated plate, orifice and perforated tube, concentric perforated tube) were investigated to obtain an improved flow distribution in a 36 channel parallel flow heat exchanger. The test section was made to closely simulate an actual heat exchanger. Tests were conducted for upward flow for the mass flux from 57 to 241 kg m〈sup〉−2〈/sup〉 s〈sup〉−1〈/sup〉 and quality from 0.2 to 0.4 using R-410A. Of the investigated insert devices, concentric perforated tube yielded the best flow distribution. Insertion of the concentric perforated tube reduced the thermal degradation from 61% to 14%. Furthermore, the preferred number of holes of the concentric perforated tube was dependent on the mass flux. At a low mass flux, an insert having small number of holes was preferred, whereas the reverse was true at a high mass flux. At a low mass flux, the effect of inlet vapor quality on flow distribution was significant. At a high mass flux, however, the effect of vapor quality on flow distribution was minimal. Possible explanations on the flow distribution behavior were provided through flow visualization in the header.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Vanessa Cristina Estevam Bittencourt, Ana Maria dos Santos Moreira, Jeferson Gomes da Silva, Antônio Frederico de Freitas Gomides, Cibele Velloso-Rodrigues, Regina Gendzzelevski Kelmann, Leonardo Meneghin Mendonça, Ivana Silva Lula, Ângelo Márcio Leite Denadai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this work was to synthesize and characterize the inclusion compounds formed by the complexation of β-cyclodextrin (βCD) with insecticides from the class of benzoylphenylureas (BPUs), named novaluron (NOV) and diflubenzuron (DIF), beyond evaluate their larvicidal activity against 〈em〉Aedes aegypti〈/em〉 larvae. Solid state characterization by FTIR showed changes in the main peaks of BPUs and βCD, suggesting the formation of inclusion compounds in solid phase. DTA and TGA thermal analysis showed changes in temperatures of BPUs decomposition as result of molecular interactions. 〈sup〉1〈/sup〉H NMR experiments allowed to observe the occurrence of interactions in solution through changes in chemical shifts of BPUs aromatic hydrogens. However, the presence of H–H intermolecular correlations in 2D ROESY was found only for the DIF/βCD complex, suggesting different topology for each complex. Such hypothesis was corroborated by thermodynamic analysis using ITC, which showed different profile of titration curves, beyond endothermic and exothermic interactions for NOV/βCD and DIF/βCD complexes, respectively. DLS titrations of BPUs or BPUs/βCD DMSO solutions in aqueous solution demonstrated that the spontaneously formed hydrophobic nanoprecipitates (HNPs) have different profile of sizes depending on the BPU/βCD system, corroborating also with the hypothesis about the existence of different topologies for each complex. Finally, the HNPs of inclusion compounds showed to be more efficient than free BPUs, allowing proposing a new insecticide formulation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Maiko Hayashida, Tsuyoshi Miyaoka, Keiko Tsuchie, Tomoko Araki, Muneto Izuhara, Shoko Miura, Misako Kanayama, Koji Ohtsuki, Michiharu Nagahama, Ilhamuddin Abdul Azis, Rostia Arianna Abdullah, Muhammad Alim Jaya, Ryosuke Arauchi, Sadayuki Hashioka, Rei Wake, Toshiko Tsumori, Jun Horiguchi, Arata Oh-Nishi, Masatoshi Inagaki〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉A reduction of GABAergic markers in postmortem tissue is consistently found in schizophrenia. Importantly, these alterations in GABAergic neurons are not global, which means they are more prevalent among distinct subclasses of interneurons, including those that express the calcium binding protein parvalbumin.〈/p〉 〈p〉A decreased expression of parvalbumin in the hippocampus is a consistent observation not only in postmortem human schizophrenia patients, but also in a diverse number of rodent models of the disease.〈/p〉 〈p〉Meanwhile, previously we reported that the congenital hyperbilirubinemia model rats (Gunn rats), which is a mutant of the Wistar strain, showed behavioral abnormalities, for instance, hyperlocomotor activity, deficits of prepulse inhibition, inappropriate social interaction, impaired recognition memory similar with several rodent models of schizophrenia. Several animal studies linked the importance of palvalbumin in relation to abnormal hippocampal activity and schizophrenia-like behavior.〈/p〉 〈p〉Here, we show that parvalbumin positive cell density was significantly lower in the CA1, CA3 and the total hippocampus of Gunn rats (congenital hyperbilirubinemia model rats) compared to Wistar control rats. The correlations between serum UCB levels and loss of PV expression in the hippocampus were also detected. The decreases in the PV-expression in the hippocampus might suggest an association of the behavioral abnormalities as schizophrenia-like behaviors of Gunn rats, compared to the Wistar control rats.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Anastasiia S. Boiko, Irina A. Mednova, Elena G. Kornetova, Arkadiy V. Semke, Nikolay A. Bokhan, Anton J.M. Loonen, Svetlana A. Ivanova〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Background〈/h6〉 〈p〉Schizophrenia is associated with a lowered life expectancy due to cardiovascular disease. This is, at least in part, related to an increased vulnerability to the development of metabolic syndrome (MetS) in patients with schizophrenia. The dysregulation of apolipoproteins (Apos) may also play a role in the pathogenesis of schizophrenia via their effect on cerebral cholesterol processing.〈/p〉 〈/div〉 〈div〉 〈h6〉Aim〈/h6〉 〈p〉The aim of this study was to investigate serum Apos A1, C3, E, A2 and C2 concentration in schizophrenia patients with or without MetS in comparison to healthy donors.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉After obtaining informed consent, 53 patients with a diagnosis of paranoid schizophrenia according to ICD-10 criteria (F20) were included. Patients were divided into two groups with (N = 26) and without (N = 27) MetS according to the criteria of the International Diabetes Federation. The control group included 20 mentally and physically healthy subjects. Serum Apos A1, A2, C2, C3 and E were measured using xMAP technology (Luminex).〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉Serum ApoA1 was significantly decreased in patients with schizophrenia compared to healthy subjects (p = 0.002); ApoA2 was lower in patients without MetS in comparison to patients with MetS (p = 0.017) and the levels of ApoC3 and ApoC2 were increased in patients with schizophrenia with MetS in comparison with the control group and also with patients without MetS. No other significant differences were established concerning the other assayed apolipoproteins.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusions〈/h6〉 〈p〉In line with literature data the results of our study suggest that while disturbances in ApoA1 level may play a role in the pathogenesis of schizophrenia, ApoA2, ApoC2, ApoC3 and ApoE may be primarily related to metabolic imbalance.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Sagar S. Arya, Mansi M. Sharma, Ratul K. Das, James Rookes, David Cahill, Sangram K. Lenka〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Antimicrobial resistance (AMR) is a serious concern in pathogenic bacteria. As a new approach to addressing AMR, we report here the green synthesis of vanillin capped gold nanoparticles (VAuNPs) using the popular flavouring molecule vanillin (C〈sub〉8〈/sub〉H〈sub〉8〈/sub〉O〈sub〉3〈/sub〉) as a reducing and capping agent. Physicochemical characterization revealed that the synthesised VAuNPs were stable and crystalline in nature. VAuNPs were non-bactericidal even at high concentration (〉2000 μg/ml). The antibiotic potentiation activity was studied in combination with seven widely used antibiotics against extremely drug resistant (XDR) 〈em〉Pseudomonas aeruginosa〈/em〉. Major reductions in minimum inhibitory concentrations (MIC, 10–14-folds) of the antibiotics meropenem (10 fold) and trimethoprim (14 fold) were observed in the presence of VAuNPs (50 μg/ml). Furthermore, it was found that VAuNPs in combination with meropenem or trimethoprim provided 1.5–3-fold better potentiation effects than that of vanillin alone. Use of an ethidium bromide agar cart wheel assay indicated that VAuNPs can block the activity of efflux pumps. High reduction in the MIC of antibiotics was therefore attributed to the efflux pump repression activity of VAuNPs. Further, RT-qPCR of clinically relevant MexAB-OprM efflux pump components showed down-regulation in 〈em〉mexB〈/em〉 and 〈em〉OprM〈/em〉 transcripts in VAuNPs treated 〈em〉P. aeruginosa〈/em〉 clinical isolates. Our results reveal that VAuNPs impart susceptibility to the last line antibiotics meropenem, trimethoprim and few widely used antibiotics in XDR 〈em〉P. aeruginosa〈/em〉 clinical isolates that display resistance to these antibiotics. Therefore, this study indicate the ability of VAuNPs and vanillin to be used as antibiotic adjuvants for inhibiting bacterial efflux pumps to potentiate antibiotics for addressing AMR problem affecting human health and environment.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Emiliano Felici, Chien C. Wang, Cristian Casado, Ana Vicario, Víctor Pereyra, María R. Gómez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, a green analytical methodology based on fluorescence derivatization is proposed for the anti-helminthic drug monitoring ivermectin as environmental emergent contaminant. After sample clean-up, ivermectin was converted into a highly fluorescent derivative through a catalytic oxidation process followed by dehydration and tautomerization. Under optimal experimental conditions, a linear response was obtained for ivermectin within the range 0.38–600 μg L〈sup〉−1〈/sup〉, with detection and quantification limits of 0.11 and 0.38 μg L〈sup〉−1〈/sup〉, both values are lower than other previously reported. This method has been applied for ivermectin determination in environmental water samples at trace levels, showing its potential for contamination monitoring.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Zemenu Bires, Sahil Raj〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study has investigated the factors that determine the conservation of one of the major ecosystem in Ethiopia, Lake Tana Biosphere Reserve, using primarily quantitative followed by qualitative approach to provide adequate results of the problem under study. The study has employed the descriptive design and a total of 305 samples from rural households (n = 159) and tourism-related enterprises (n = 146) were selected based on a stratified random sampling technique. Samples were drawn based on their direct attachment either in their livelihood and possess a responsibility to the study area. Data were collected through questionnaires, observation, focus group discussion, unstructured interview and secondary data was consulted. Exploratory factor analysis was used to extract dimensions for environmental awareness. Binary logistic regression was used to analyze data using SPSS version 23. Ten Socio-demographic variables of samples were used as an independent variable and environmental conservation dimensions as dependent variables. The result revealed that out of the 10 variables employed in the analysis, six variables were found significant. Hence, marital status, household size, income source, household income, membership to club and resident location were found to be significant. Qualitative analysis revealed wrong reports for political consumption driven little government attention and lack of integrated natural resource management policy and plan were major factors hindering conservation. A vivid and holistic destination management policy making with enough room to stakeholders' involvement shall be a prior task for the government for better conservation of the ecosystem and sustainable development.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Yogendra Kumar, Panchanan Pramanik, Dipak Kumar Das〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Some electrodes for efficient detection of paracetamol and dopamine were developed from nano sized material of cobalt ferrite (np-CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉) and manganese ferrite (np-MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉). These oxides were synthesized by combustion method using cobalt nitrate, manganese acetate and ferric nitrate as precursors in the presence of sugar and ethanolamine. The crystallite size, shape and morphology of nano material were characterized by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The crystallite sizes of synthesized nano-particles (nps) were in the range from 10 to 12 nm (calculated using Debye-Scherrer equation) with cubic crystal system. These particles were utilized as electrode modified with graphite for simultaneous detection of paracetamol and dopamine through cyclic voltammetry and Differential pulse voltammetry techniques and was found to be superior to reported literatures. The minimum detection limit of paracetamol and dopamine at CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/GP electrode were 250 nM and 350 nM while at MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/GP electrode it was 300 nM and 400 nM, respectively. Both the electrodes exhibited the linearity range from3 μM to 200 μM & 3 μM–160 μM for paracetamol and 3 μM–180 μM & 5 μM to 200 for dopamine, respectively. Two oxidation peaks of paracetamol and dopamine were well separated in phosphate buffer (pH = 6) in mixture with 100 mVs〈sup〉-1〈/sup〉 and 50 mVs〈sup〉-1〈/sup〉 scan rate for cyclic voltammetry and Differential pulse voltammetry, respectively. Both the electrodes demonstrated satisfactory results in real samples of paracetamol and dopamine.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Ahmed A. Abdurahman, Eshetu E. Chaka, Mohammed H. Bule, Kamal Niaz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Background & aim〈/h6〉 〈p〉Concurrent estimates on the magnitude and evidence on the determinants of complementary feeding (CF) practices in Ethiopia are currently disparate. Hence, this systematic review and meta-analysis assessed the magnitude and determinants of CF among children age 6–23 months in Ethiopia.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉Studies from various databases published until July 2018 were identified, selected, extracted and assessed for risk of bias by two authors independently. A random-effects model was used to pool the prevalence and odds ratios (ORs).〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉26 studies with 17, 383 children were included. The pooled prevalence estimate of timely initiated CF, minimum dietary diversity (DD), minimum meal frequency and minimum acceptable diet were 61.0%, 18.0%, 56.0%, and 10.0% respectively. The pooled prevalence of timely initiation and minimum DD were higher in Northern Ethiopia. On the other hand, except for the minimum meal frequency, all the three core indicators of CF were better in urban than rural settings. Child age, maternal and/or paternal education, paternal involvement, maternal DD, antenatal and postnatal care, and place of delivery were the main determinants that can increase appropriate CF practices.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusion〈/h6〉 〈p〉The reported estimates of the prevalence of core CF indicators in Ethiopia remained poor. Therefore, the authors would like to acknowledge the effort that has been done by the minister of health and its partners including Alive & Thrive to improving CF practices in the country, however, these programs should be done more thoroughly, and scaled up by applying and adapting tested, proven approaches and tools in contexts.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Carolina Gonzaga Carvalho, Richard Bresler, Ying Xuan Zhi, Hisham Alshaer, John T. Granton, Clodagh M. Ryan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Objectives〈/h6〉 〈p〉Our aims were to evaluate HRV in pulmonary hypertension (WHO Group 1 and 4) compared to control subjects, and to assess whether the presence of sleep apnea in those with pulmonary hypertension would be deleterious and cause greater impairment in HRV.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉This retrospective case-control study analyzed electrocardiogram segments obtained from diagnostic polysomnography.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉Forty-one pulmonary hypertension patients were compared to 41 age, sex and apnea-hypopnea index matched healthy controls. The pulmonary hypertension group had decreased high frequency, very low frequency, low frequency, and percentage of normal R-R intervals that differ by 〉 50 ms compared to control subjects. Moderate to severe right ventricle dysfunction on echocardiography was a predictor of lower high frequency in pulmonary hypertension patients.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusions〈/h6〉 〈p〉There were no differences in any HRV measures in pulmonary hypertension patients with or without sleep apnea. Impaired HRV was demonstrated in pulmonary hypertension patients however, the presence of sleep apnea did not appear to further reduce vagal modulation.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Francisco González Santa Cruz, Juan Choque Tito, Jesús Claudio Pérez-Gálvez, Miguel Jesús Medina-Viruel〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gastronomy allows tourists to discover the cultural roots of the destination, thus being one of the motivations for its choice and even becoming a fundamental factor in the analysis of the overall satisfaction of the tourist experience. This research is focused on the analysis of the gastronomic experiences of foreign tourists who visit the city of Oruro (Bolivia). The main results of this research show a segmentation of travellers on the basis of their perceptions regarding the gastronomic experiences in this city into three different groups (survivors, enjoyers, and experiencers). Additionally, the study concludes that these gastronomic experiences are highly related to the motivations that the travellers have to discover a specific destination, and that their level of satisfaction with these experiences is highly connected to the relationship that gastronomy has with the cultural heritage of the local community.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Oluwamayowa Olalekan Iredele〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper examines the quality of integrated reports of listed firms in South Africa and the associated factors. Data were obtained from a sample comprising 100 firm-year observations of 20 companies in Johannesburg Stock Exchange over the period (2013–2017). Analysis of data involves descriptive statistics, spearman rank correlation analysis and Kruskal-Wallis H test. The result shows a significant relationship between the quality and length of integrated reports. Firms vary in the level of quality of their integrated reports on the account of differences in profitability, board size, gender and firm size. No significant relationship was found between quality of integrated reports and leverage. The result of this study indicates that the length of the integrated report signals the level of quality of such report, which may be necessary in disclosing all material matters to satisfy the needs of a wide range of stakeholders.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): R. Sharma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this work is to investigate the effect of angle of incident light on the performance of silicon solar cell. In this regard, numerical calculations have been performed to obtain the reflectance for double layer antireflection coating (DLARC) of Si〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 at various angles of incidence (i.e.〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msup〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈mo〉,〈/mo〉〈msup〉〈mrow〉〈mn〉15〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈mo〉,〈/mo〉〈mspace width="0.25em"〉〈/mspace〉〈msup〉〈mrow〉〈mn〉30〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈mo〉,〈/mo〉〈mspace width="0.25em"〉〈/mspace〉〈msup〉〈mrow〉〈mn〉45〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈mo〉,〈/mo〉〈mspace width="0.25em"〉〈/mspace〉〈mi〉a〈/mi〉〈mi〉n〈/mi〉〈mi〉d〈/mi〉〈mspace width="0.25em"〉〈/mspace〉〈msup〉〈mrow〉〈mn〉60〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉) using transfer matrix method. Reflectances obtained, are found to increases with increase in angle of incidence. Calculated reflectances have been further used in the PC1D simulator as external reflectance files to study the performance of silicon solar cell. As a result of the simulation, the conversion efficiency (and short circuit current) of solar cell is found to decrease by 1.7% (0.062 mA/cm〈sup〉2〈/sup〉) with increase in angle of incidence from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈msup〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈mspace width="0.25em"〉〈/mspace〉〈mi〉t〈/mi〉〈mi〉o〈/mi〉〈mspace width="0.25em"〉〈/mspace〉〈msup〉〈mrow〉〈mn〉60〈/mn〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 7〈/p〉 〈p〉Author(s): Saleem Ali Banihani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Testosterone is an anabolic steroid and the principal sex hormone in males. Maintaining adequate levels of testosterone throughout the life span of male is very desirable, especially it is now well-known that low levels of testosterone is associated with various aging diseases/disorders. Therefore, still, so many research studies have focused on enhancing serum levels of testosterone in males. Here, we intended to systematically discuss and present the impact of honey on serum levels of testosterone in males. This was conducted by searching PubMed, Scopus, and Embase electronic databases for research articles from May 1993 through April 2019 using the keywords “honey” and “honeybee” versus “testosterone”. Moreover, references from relevant published articles were also reviewed and cited to frame an integral discussion, conclusion, and future research needs. In conclusion, the collective evidence, which is mainly based on in vivo system studies, reveals that oral administration of honey increases serum testosterone level in males. Mechanistically, honey may increase serum level of testosterone by increasing the production of luteinizing hormone, enhancing the viability of Leydig cells, reducing oxidative damage in Leydig cells, enhancing StAR gene expression, and inhibiting aromatase activity in the testes. However, further research studies on humans, mainly clinical trials, in this specific research approach are still needed to confirm the effect of honey on testosterone.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Rohit Singla, Kanchan Chowdhury〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cryogenic air separation plants producing pressurized gaseous oxygen (PGOX) near 40 bara at purities 99.8% and 95% and gaseous nitrogen at 5 bara above 99.99% purity are analyzed. Oxygen is compressed either by external compression process (EC) or by internal compression (IC). IC is gasification of pumped liquid oxygen in the main heat exchanger (MHX). IC plants require appropriate combinations of pressure and flow of air and size of the MHX to vaporize PGOX with reasonable specific power consumption (SPC). Based on exergy and economic analyses of the ASU after simulating the plant in Aspen HYSYS®™8.6, the values of parameters which give high exergy efficiency with low capital and operating expenditures are determined. SPC of IC is 7–8% higher than that of EC. Addition of crude argon column improves the purity of oxygen from 96.3% to 99.8%. Recovery of oxygen improves by 5% with 3–4% reduction of SPC for both types of plants. Capital requirement for both EC and IC plants is about 50% higher with argon separation than without it. HP air between 33% and 31% of total air flow at 70 bara and 80 bara respectively is the most preferred range of operation of IC plants for 95% purity of oxygen. The corresponding flow of HP air is 5% lower for 99.8% purity of oxygen.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Medhat M. Sorour, Wael M. El-Maghlany, Mohamed A. Alnakeeb, Amgad M. Abbass〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An experimental investigation was conducted in order to study heat transfer between a vertical free surface jet and a horizontal stainless steel heated plate. The jet was composed of water-〈em〉SiO〈sub〉2〈/sub〉〈/em〉 nanofluid with an average particle size of 8 nm delivered from a fixed nozzle diameter of 6 mm. The results covered a wide range of jet Reynolds number up to 40000, ten nanoparticle volume fractions (0% ≤ 〈em〉φ〈/em〉 ≤ 8.5%), five jet aspect ratios (〈em〉z/d〈/em〉 = 0.5, 1, 2, 4 and 8) and plate radius to jet diameter ratio (〈em〉r/d〈/em〉) up to 12.5. The experimental results illustrated that the enhancement of the average Nusselt number increases with the volume fraction and Reynolds number. Therefore, the volume fraction can significantly provide a heat transfer enhancement of the average Nusselt number up to 80% for a volume fraction of 8.5% compared to pure water. Conversely, the effect of nozzle to plate aspect ratio (〈em〉z/d〈/em〉) is not significant. Finally, a new heat transfer correlation has been proposed for the average Nusselt number as a function of Peclet number, a nanoparticle volume fraction, a plate to jet diameter ratio and a nozzle to plate aspect ratio.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Grayson Lange, Luca Carmignani, Subrata Bhattacharjee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Radiative emission from a flame is an important component of the heat transfer balance between flame and surroundings. When the residence time of the oxidizer increases radiation plays an important role, and a practical example is given by microgravity flames where the lack of buoyancy creates larger time scales of the problem. With a strong opposed-flow, however, radiation could become a secondary effect. This study presents experimental measurements of thermal radiation from downward spreading flames over thin sheets of PMMA (polymethyl methacrylate) in a normal gravity environment and no forced flow. Radiation data from these downward spreading flames can serve as a baseline for future microgravity experiments. The presented experiments are performed in an apparatus called Flame Stabilizer where a spreading flame is turned stationary in laboratory coordinates by moving the sample upwards at the same velocity as the downward spreading flame. A radiometer, capable of line of sight measurement, is mounted on a x-y-z position controller and used to map the radiation emitted by the flame and the burning solid perpendicular to the fuel surface. After establishing repeatability and consistency of the results, a family of radiation profile curves is generated to map the radiation field. The experiments are then repeated by varying fuel thickness; larger fuel thicknesses are found to generate stronger radiation signals as the flame size becomes bigger. Furthermore, the radiative response to the presence of char in a flame is illustrated by comparing the PMMA results with a cellulosic fuel. With the unburnt solid in the flame region, radiative emissions significantly increase.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): X. Zheng, Z. Lin, B.Y. Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Desiccant coated aluminum fins are an important part of desiccant coated heat exchangers (DCHEs). The overall performance of DCHE-based systems benefits from improved heat and mass transfer characteristics of desiccant coated aluminum fins. In this paper, a new type of nano-silver powder supported FAPO-34 composite fin is proposed. Samples with different mass percentages of nano-silver powder were fabricated and related characteristics including thermal conductivity, cycle water uptake and adsorption/desorption performance were investigated. Our experimental results show greatly improved thermal conductivity of nano-silver powder supported composite sheets. Analysis of the adsorption testing confirmed that the nano-silver powder improved dynamic adsorption performance, and adsorption rate coefficients of composite sheets increasing by 6–103% compared with that of a pure FAPO-34 coated sheet. The composite samples also exhibited better dynamic desorption performance, in that their desorption rate coefficients increased to be 1.3–2.3 times as great as those of the pure FAPO-34 sample.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Xinpeng Zhao, Sohrab A. Mofid, Majed R. Al Hulayel, Gabriel W. Saxe, Bjørn Petter Jelle, Ronggui Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Highly transparent and low thermal conductivity materials have attracted great interest for the applications in window insulation in recent years. Accurate characterization of the thermal properties including thermal transmittance (U-value) and thermal conductivity of window insulation materials is very important for developing next-generation materials. The conventional hot box method, which is commonly used to measure the U-values of building materials, requires sample sizes 〉 1.0 m〈sup〉2〈/sup〉 to minimize the influence of parasitic heat loss on the measurement accuracy. This characterization challenge hinders the development of novel window materials which are not yet available for large-scale deployment. To address this issue, a reduced-scale hot box system (RHS) was designed to measure both the U-value and the thermal conductivity of specimens that can be more readily made, with sizes 〈 0.2 m × 0.2 m. The developed reduced-scale hot box system has a very simple testing system and can avoid the challenging thermal insulation requirement of the conventional hot box. The fast turnaround of the reduced-scale hot box system can help facilitate the development of novel insulating materials for energy-efficient windows.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Thi-Thao Ngo, Chi-Chang Wang, Jin H. Huang, Van-The Than〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents an inverse method for predicting the heat source and temperature during Gas Metal Arc Welding (GMAW). A combination of finite element thermal model and optimized technique is used to give inverse solutions. Simulated results show that the estimated temperatures and heat source are in good agreement with the exact solutions. Experiments are then performed to measure real temperature data which are further utilized for inversely predicting the heat source and temperature field. The experimental inverse results indicate that the predicted temperatures have a good correlation with the measured data, and the heat source is carried out for different welding conditions. To verify accuracy of the inverse results, a comparison of temperature at validated point is implemented. In addition, the temperatures at the welding area which are difficult to directly measure are also obtained. The proposed method may be applied to optimize welding condition for other welding processes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Mingyue Ding, Chenzhen Liu, Zhonghao Rao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to enhance the heat transfer performance of phase change material (PCM) for thermal energy storage (TES) in tiny devices, such as battery thermal management, light-emitting diode and electronic device cooling, TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O nanofluids and the microchannel were combined in this paper. Two crystal forms of TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O nanofluids were prepared by using a two-step method. And paraffin was used as PCM. The stability and thermophysical properties of the above two nanofluids were tested and compared. It can be found that R TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O nanofluid has better stability, and its thermal conductivity increases maximally by 3.27%, while the value is 2.88% of A TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O. Besides, R TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O nanofluid increases the viscosity by a maximum of 4.87%, while A TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O increases by 7.45%. Considering these properties, R TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O nanofluid was chosen to study the heat transfer characteristics in the microchannel within a TES unit. The results indicate that R TiO〈sub〉2〈/sub〉-H〈sub〉2〈/sub〉O nanofluid with 1.0 wt% increases Nu by 19 ∼ 41% and 6 ∼ 14% during the melting process and solidification process respectively. In addition, the melting time of paraffin decreases by a maximum of 32.90% and the solidifying time of paraffin decreases by a maximum of 22.57%. During the whole TES process, there is an increase in pressure drop of no more than 8%.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): C. Coomansingh-Springer, V. Vishakha, A. Montanez Acuna, E. Armstrong, R.N. Sharma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉This study identified the endoparasites in Brown rat (〈em〉Rattus norvegicus)〈/em〉 during May to July 2017 in Grenada, West Indies. A total of 162 rats, 76 females and 86 males were trapped from St. George and St. David parishes in Grenada. The collected fecal samples were examined for parasitic eggs and/or oocysts using simple fecal flotation technique. Adult parasites found in the intestinal tract were examined for identification. The overall prevalence of intestinal parasites among rats was 79 %.〈/p〉 〈p〉Ten helminth species were recovered, several of which were reported for the first time in rodents in Grenada. The internal parasites consist of seven nematodes (〈em〉Angiostrongylus〈/em〉 spp., 〈em〉Nippostrongylus braziliensis〈/em〉, 〈em〉Heterakis spumosa〈/em〉, 〈em〉Strongyloides ratti〈/em〉, 〈em〉Aspiculuris tetraptera〈/em〉, 〈em〉Syphacia〈/em〉 spp. and 〈em〉Protospirura〈/em〉 spp.), one cestode (〈em〉Hymenolepsis diminuta〈/em〉), one acanthocephalan (〈em〉Moniliformis moniliformis〈/em〉) and one protozoa species (〈em〉Eimeria〈/em〉 spp.). The most prevalent zoonotic species were 〈em〉Angiostrongylus〈/em〉 spp. (35.2%), 〈em〉Hymenolepsis diminuta〈/em〉 (7.4%) and 〈em〉Moniliformis moniliformis〈/em〉 (3.1%). Several nonzoonotic endoparasites; which included 〈em〉Nippostrongylus braziliensis〈/em〉 (50.6%), 〈em〉Heterakis spumosa〈/em〉 (15.4%), 〈em〉Strongyloides ratti〈/em〉 (43.2%), 〈em〉Aspiculuris tetraptera〈/em〉 (2.5%), 〈em〉Syphacia〈/em〉 spp〈em〉.〈/em〉 (1.9%), 〈em〉Protospirura〈/em〉 spp. (1.2%) and 〈em〉Eimeria〈/em〉 spp. (4.7%) were also identified. The most prevalent parasites were 〈em〉Nippostrongylus brasiliensis〈/em〉 (50.6%), 〈em〉Strongyloides ratti〈/em〉 (43.2%) and 〈em〉Angiostrongylus spp.〈/em〉 (35.2%). Co-infections occurred with up to six species per rat showing different combinations of parasitic infections.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): R.M. Dodo, T. Ause, E.T. Dauda, U. Shehu, A.P.I. Popoola〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigates the possibility of multi-objective optimization in the transesterification of mahogany seed oil (MSO). The Taguchi method together with Grey relational analysis (GRA) was used to maximize both percent fatty acid methyl ester (FAME) yield and heat transfer coefficient (HTC). It was found that methanol to oil molar ratio was the factor that contributed the most in obtaining high percent FAME (ester) yield and HTC. Employing the following conditions: 32.6 wt% methanol (9:1 methanol to oil molar ratio), 0.5 wt% catalyst, 60 °C temperature and 300 rpm agitation was found to offer an improved percent ester yield and HTC. A confirmatory test resulted in an ester yield of 90.1 % and HTC up to 153.0 W/m〈sup〉2〈/sup〉K. The structure of the optimized transesterified mahogany seed oil (TM) was confirmed by FTIR analysis. In the event of comparison, TM, raw mahogany seed oil (FM) and SAE40 were analyzed by cooling curve analyses. TM identified to have superior quenching performance.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Amir Sharafian, Paul Blomerus, Walter Mérida〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fugitive methane emissions from the liquefied natural gas (LNG) supply chain have revealed uncertainty in the overall greenhouse gas emissions reduction associated with the use of LNG in heavy-duty vehicles and marine shipping. Methane is the main constituent of natural gas and a potent greenhouse gas. Recent measurements have shown that the LNG offloading process had the largest contribution to methane emissions in the refueling portion of the supply chain. However, there are limited studies analyzing the LNG offloading process for small-scale applications. This study investigates six methods used to offload LNG from a tanker truck to an LNG refueling station and their contribution to methane emissions. A verified thermodynamic model is created by comparing numerical results with the experimental data collected from an LNG offloading process in a refueling station. The modeling results show that the LNG transfer by using a pressure buildup unit causes methane emissions as high as 104 g/kg LNG. In contrast, LNG transfer by using a pump and controlled pressure buildup unit provides the lowest risk of methane venting. Also, the results of parametric study indicate that rigid foam insulation can be considered as an economical alternative to vacuum jacketed pipes in LNG refueling stations.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Cheng Zeng, Shuli Liu, Liu Yang, Xiaojing Han, Ming Song, Ashish Shukla〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For some renewable energy such as solar energy, the mismatch between the side of generation and demand should be tackled by thermal energy storage techniques with high energy density and low thermal losses. Thermochemical energy storage is a promising technology to meet these requirements. Within a thermochemical energy storage system, reactor is one of the critical components to achieve the optimal performance. While few studies have investigated the three-phase reactor applied in open thermochemical system in building’s application. This study presents a numerical description of a three-phase thermochemical reactor with air, solid thermochemical material and water flow. Zeolite 13X has been selected as the working thermochemical material and experimental tests have been conducted to obtain the temperature profiles in both the charging and discharging processes. A two dimensional numerical model of the reactors has been developed, verified and validated. A good agreement has been obtained by comparing the numerical and experimental results with the root mean square percent error ranging from 6.02% to 12.29%. Additionally, parameters sensitivity analysis has been conducted for reference diffusivity, heterogeneity factor, and initial water uptake of the zeolite. The numerical model and the investigation provide the tool for reactor design optimisation, charging and discharging processes evaluation and reactor performance improvement.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Dan Dan, Chengning Yao, Yangjun Zhang, Hu Zhang, Zezhi Zeng, Xiaoming Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An effective battery thermal management system is crucial for electric vehicles because the performance of lithium ion battery is sensitive to its operating temperature. In this study, a thermal management system equipped with micro heat pipe array (MHPA) is designed. An equivalent thermal resistance model is developed for MHPA based on thermal circuit method. The accuracy of the proposed model is validated by comparing the simulation results with experimental data under steady and dynamic and operating condition. A validated lumped thermoelectric model is adopted for prismatic lithium ion battery. The proposed thermal resistance model is combined with the battery model in order to predict the transient temperature distribution of a battery pack based on MHPA cooling. Simulations are conducted for air-cooled MHPA thermal management system. Temperature rise and temperature gradients of the designed cooling system are compared with direct forced convection. Simulation results demonstrate that the MHPA-based battery thermal management provides a quick response to ensure the temperature stability during rapid changing operating condition.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Nguyen Ngoc Bao Chau, Nguyen Thi Phung Kieu, Nguyen Van Tri Dung, Nguyen Bao Quoc, Truong Kim Phuong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Parasitoids are important biological control of crop pests. In Vietnam, 〈em〉Cotesia vestalis〈/em〉 is a native wasp species that has demonstrated its applicability as a natural insect pest enemy. Many adult parasitoids require food resources such as nectar and pollen to optimize their life cycles. Potential effects of yellow cosmos (〈em〉Cosmos sulphureus〈/em〉), shrub verbena flower (〈em〉Lantana camara〈/em〉), common zinnia (〈em〉Zinnia elegans〈/em〉), and coriander flower (〈em〉Coriandrum sativum〈/em〉 L.) on the longevity and parasitism of 〈em〉C. vestalis〈/em〉 were investigated. Results showed that nutrition resources from yellow cosmos (〈em〉C. sulphureus〈/em〉) and shrub verbena flower (〈em〉Lantana camara〈/em〉) significantly increased the longevity of 〈em〉C. vestalis〈/em〉 in comparison with water (P 〈 0.001). Kaplan-Meier estimates of survival functions of female 〈em〉Cotesia vestalis〈/em〉 exposed to different food sources indicated a significant difference in the treatments (P 〈 0.01). Male and female wasps feeding on 〈em〉Cosmos sulphureus〈/em〉, 〈em〉Lantana camara〈/em〉, and 〈em〉Coriandrum sativum〈/em〉 survived significantly longer than wasps fed on water or 〈em〉Zinnia elegans.〈/em〉 Parasitism efficiency of 〈em〉C. vestalis〈/em〉 was tested on diamondback moth 〈em〉Plutella xylostella〈/em〉 (L.) larvae for different food resources. 〈em〉Cosmos sulphureus〈/em〉, 〈em〉Lantana camara, Coriandrum sativum〈/em〉 treatments gave the different mean number of emergence parasitoids per day compared to water treatment. Results implied that food resources from flowers benefitted the longevity of 〈em〉C. vestalis〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Jordan P. Howell, Katherine Schmidt, Brooke Iacone, Giavanni Rizzo, Christina Parrilla〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reliable data about collection, volume, tonnage, stream composition, and disposal price have long been described as key components of successful solid waste management planning. Yet, concerns about data quality and quantity have continued to limit even the most sincere, progressive waste management schemes. This paper examines solid waste management data that has been collected in the US state of New Jersey starting in the 1960s. We present the origins of waste management data collection in New Jersey and trace some of the applications that have been made with the data over time. We compare the New Jersey dataset to waste management data that has been collected in other US states. We then describe our work collecting, cleaning, and preparing for public dissemination and use in a geospatial visualization exercise a digital version of the data spanning approximately 1993 to 2016, before presenting some illustrations of the type of modeling and analysis that researchers or the concerned public would be able to undertake now that the dataset is available. (We are publishing the 1993–2016 dataset alongside this paper). We argue that the New Jersey waste management dataset is much better than most other waste datasets in the US, but despite this fairly high quality, there remain significant gaps which inhibit the ability of planners to design and implement comprehensive waste management plans. That there are limits inherent to the New Jersey dataset suggests, we argue, a ceiling to the usefulness of waste management data as a category of environmental knowledge with possible implications for ‘big’ environmental data more broadly.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Daisuke Kurumazuka, Kento Kitada, Ryosuke Tanaka, Tatsuhiko Mori, Mamoru Ohkita, Masanori Takaoka, Yasuo Matsumura〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Aim〈/h6〉 〈p〉α-Lipoic acid exerts a powerful antioxidant effect by acting as a free radical scavenger and inducing endogenous antioxidants such as vitamin E and glutathione. In the present study, we examined the effects of α-lipoic acid on cardiac dysfunction in rat hearts with aortocaval fistulae.〈/p〉 〈/div〉 〈div〉 〈h6〉Main methods〈/h6〉 〈p〉Aortocaval fistulae were created between the abdominal aorta and inferior vena cava in male rats. Hemodynamic parameters were measured 14 days after surgery using an intravascular pressure transducer, and then these hearts were harvested for tissue weight measurement, pathological evaluation, and mRNA isolation.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉In vehicle-treated rats, left ventricular end-diastolic pressure and left ventricular weight significantly increased at 14 days after fistula creation. Fistula-creation resulted in expression of 4-hydroxy-2-nonenal, NADPH oxidase subunit p67〈sup〉phox〈/sup〉 and BNP mRNA in a time-dependent manner in the left ventricle.〈/p〉 〈p〉Long-term treatment (initiated 2 days before surgery, and continued for 14 days after fistula creation; days -2 to 14) with α-lipoic acid (30 mg/kg/day) markedly suppressed the increases in left and right ventricular weight, and left ventricular end-diastolic pressure. α-Lipoic acid treatment from days -2 to 14 prominently prevented the expression of 4-hydroxy-2-nonenal and NADPH oxidase subunit p67〈sup〉phox〈/sup〉, and significantly raised BNP mRNA levels. Short-term treatment with α-lipoic acid from day - 2 to 7 was effective in preventing cardiac enlargement and dysfunction, similar to long-term treatment, but treatment from days 7–14 was not effective.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusions〈/h6〉 〈p〉Treatment with α-lipoic acid can prevent cardiac hyperplasia and dysfunction, probably by inhibiting superoxide production and enhancing BNP mRNA expression in an early phase after fistula creation.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Randa R. Elmorsi, Khaled S. Abou-El-Sherbini, Gamal Abdel-Hafiz Mostafa, Mohamed A. Hamed〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lake Manzala is the largest and most productive lake of Egypt's northern coastal lakes and has socio-economic impacts. Pollution by heavy metals is the most significant type of pollution worldwide, particularly in Lake Manzala, which receives mixed discharges from densely populated areas. Water samples were collected at twelve sites around the lake in winter and summer of 2015. Samples of 〈em〉Eichhornia crassipes〈/em〉 were collected in the winter, and 〈em〉Oreochromis niloticus〈/em〉 samples were collected at two sites (8 and 10). V, Cr, Mn, Fe, Co, Ni, Cu, and Zn were analysed in these samples using inductively coupled plasma-mass spectrometry. The average metal concentrations were below the internationally accepted upper permissible limits and are improved compared to those in previous studies. However, the metal concentrations at the eastern and southeastern sites were higher than the allowable limits due to multiple waste discharges. Pollution assessment using pollution risk indicators indicated low to moderate concentrations of metal enrichment in the sediment and biota of the lake, except at sites near the eastern and southeastern drains; these latter sites were considered to be hazardous and should be taken into account in the current development efforts of the lake. Complete removal of floating plants transported by drains is recommended〈em〉.〈/em〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Fatemeh Gh.Barkish, Rostam Jalali, Amir Jalali〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Background〈/h6〉 〈p〉A diagnosis of HIV (human immunodeficiency virus) infection causes a wide range of mental challenges regarding the meaning and understanding of such a diagnosis because of the specific nature of HIV and its social consequences. AIDS patients perceived their disease as multidimensional Stigma and rejection and even discrimination and insult in receiving health services. Therefore, a deep awareness and understanding of an individual's meaning and interpretation of a HIV-positive diagnosis and their relevant experiences are essential for providing better care.〈/p〉 〈/div〉 〈div〉 〈h6〉Objective〈/h6〉 〈p〉This study aimed to examine the attitude, understanding, and interpretation of a positive diagnosis of HIV.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉The present qualitative study was based on the descriptive phenomenological method. Participants included 13 HIV-positive patients who had been referred to the Kermanshah Counseling Center for Behavioral Diseases in Iran and diagnosed at most 6 months before being interviewed. The data were collected via semi-structured in-depth interviews.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉The continuous analyses of the data and the interview notes resulted in the identification of five main themes: contagious disease with two subthemes Illness and Harm to others, new self with a Crisis of identity subtheme, disappointment with the life ending and impending death subtheme, unmentionable disease with two subthemes secretive and horrifying diseases, and loss with Frustration subtheme.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusion〈/h6〉 〈p〉Because the attitudes and behaviors of other people, such as relatives and people in society had a negative impact on the participants' mental status, as well as on their perceptions and understanding about the positive diagnosis, the focus of care for people with HIV/AIDS should shift from therapeutic issues to socio-cultural ones. These issues play a major role in forming an individual's understanding of HIV and can be a vital factor in improving their activities and adaptations to a positive diagnosis.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): P. Ganesh Kumar, D. Sakthivadivel, M. Meikandan, V.S. Vigneswaran, R. Velraj〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The main aim of this present work is to explore the influence of dispersion of MWCNTs in a mixture of water-solar glycol (70:30) on its electrical conductivity and thermophysical properties such as density, rheology and thermal conductivity. The MWCNTs were seeded with a various weight percentage of 0.15, 0.3 and 0.45 via a common two-stage synthesis technique. The homogeneous stability of MWCNTs based nanofluids was confirmed by high-resolution scanning electron microscopy and ultraviolet-visible spectroscopy. The density of solar glycol and H〈sub〉2〈/sub〉O mixture based MWCNTs nanofluids were measured with standard borosil volumetric flask via weighing balance mechanism and the experimental findings displayed a good agreement with the well-known correlation of Pak and Cho owing to the natural packing of H〈sub〉2〈/sub〉O inside the nanomaterial in a limited quantity. The thermal conductivity of 0.45 wt. % MWCNTs seeding got augmented by 19.12% at ambient temperature while the electrical conductivity got augmented by 93.54% at 50 °C. Therefore, the augmentation in the thermal conductivity of water/solar glycol mixture with 0.45 wt. % MWCNTs seeding is because of the kinetics of nanomaterial accumulation and fluid layering. In addition, mathematical correlations were recommended for estimating the ratio of the thermal conductivity and viscosity of the nanofluid at different weight fractions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Sahar Zare, Abdollah Derakhshandeh, Masoud Haghkhah, Zahra Naziri, Azar Motamedi Broujeni〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Staphylococcus aureus〈/em〉 is an opportunistic bacterium which is carried as a normal flora organism but has a major role in the epidemiology and pathogenesis of different staphylococcal infections in humans and animals. Fifty 〈em〉S. aureus〈/em〉 isolated from banknotes, foods, human infections and bovine mastitis were subjected to DNA fingerprinting by randomly amplified polymorphic DNA (RAPD) analysis to examine their genotypic polymorphism and investigate the amount of genetic relatedness among these various isolates. At 100% RAPD profile similarity level, isolates were classified into four, five and seven groups of the same clone, according to the RAPDPCR with OLP6, OLP11 and OLP13 primers, respectively. Amplification of the isolates resulted in several polymorphic bands ranged from 〉50 to 〉1500 bp in size. Maximum number of bands was obtained by primer OLP13 which produced seven bands in bovine mastitis isolates. Most polymorphisms were observed in isolates of bovine mastitis and the lowest were associated with human infections isolates. There was no relationship between the RAPD patterns and the sources of isolates, except the three clusters which showed host specificity and only included the strains from the same sources. The results confirm the wide genotypic diversity of the studied 〈em〉S. aureus〈/em〉 strains. RAPD-PCR technique can be a valuable tool for assessing the genetic relationship, detection of polymorphism in 〈em〉S. aureus〈/em〉 and tracing the sources and management of 〈em〉S. aureus〈/em〉 infections.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): M. Ijaz, M. Ayub〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This article investigates the mixed convective flow of Jeffrey fluid near the axisymmetric stagnation point over an inclined permeable stretching cylinder. Analysis subjected to Cattaneo-Christov heat flux, thermal stratification and homogeneous-heterogeneous reactions are accounted. Suitable transformations are employed to obtain nonlinear ordinary differential system. Non-dimensional system is computed by Homotopy technique. Graphs and tables are constructed to analyze the influence of different flow parameters on temperature, concentration and velocity fields. The interpretation of skin friction coefficient is deliberated. It is noticed from obtained results that temperature is a decreasing function of thermal stratification parameter. Reverse behaviour of concentration is witnessed for higher estimations of homogeneous and heterogeneous parameters. Numerical results are compared with previous published results and found to be in good agreement for special casesof the emerging parameters.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Sarita Morakul, Yuichi Otsuka, Kiyoshi Ohnuma, Motohiro Tagaya, Satoshi Motozuka, Yukio Miyashita, Yoshiharu Mutoh〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this study was to reveal the mechanism of enhancement of antibacterial properties of gray titania by plasma-sprayed hydroxyapatite (HAp)–amino acid fluorescent complexes under irradiation with visible light. Although visible-light–sensitive photocatalysts are applied safely to oral cavities, their efficacy is not high because of the low energy of irradiating light. This study proposed a composite coating containing HAp and gray titania. HAp itself functioned as bacteria catchers and gray titania released antibacterial radicals by visible-light irradiation. HAp-amino acid fluorescent complexes were formed on the surface of the composite coating in order to increase light intensity to gray titania by fluorescence, based on an idea bioinspired by deep-sea fluorescent coral reefs. A cytotoxicity assay on murine osteoblastlike cells revealed that biocompatibility of the HAp–amino acid fluorescent complexes was identical with the that of HAp. Antibacterial assays involving 〈em〉Escherichia coli〈/em〉 showed that the three types of HAp–amino acid fluorescent complexes and irradiation with three types of light-emitting diodes (blue, green, and red) significantly decreased colony-forming units. Furthermore, kelvin probe force microscopy revealed that the HAp–amino acid fluorescent complexes preserved the surface potentials even after irradiation with visible light, whereas those of HAp were significantly decreased by the irradiation. Such a preservative effect of the HAp–amino acid fluorescent complexes maintained the bacterial-adhesion performance of HAp and consequently enhanced the antibacterial action of gray titania.〈/p〉〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Aykut Zongur〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, a rasterized mesh construction of our 3D solid-state model is generated to achieve an improved rasterization of a rigid-body surface using a series of polygonal model transfers. In the field of remodeling, auxiliary starters have been obtained from either ready-made or fabricated input point datasets. Building 3D solid meshes from clusters of inbound points to model objects is made possible by our method. Demonstrative illustrations of how the initial series of points can be transferred to mesh models by passing through the boundary conditions are presented using a customized method. A handmade weaving technique combines each different cluster of points, yielding a relevant transformation result. Additionally, newer remodeling methods involve more than the adaptation of boundary values to generate solid surfaces via finite restructuring of geometrical building blocks; our remodeling methods have been optimized in terms of both realism and computational costs. Our reconstructions are highly optimized to achieve high-quality and realistic results within a reasonable time. In higher-order creative restorations, our boundary conditions are regularized by quadratic equalizer functions. Areal-based regularizations are combined within mixed boundary values over 3D multigrids of finite differential combinations. Newly created solid models are reshaped by exclusive reconstructions to form our final models. Equally distributed multidimensional grids are seamlessly rebuilt via an ideal model-driven process with our tri-variational remodeling method that is constrained by a mixture of boundary conditions. Here, our remodeling method continuously triangulates the discrete topological structures as solid models. The final model shapes are triangulated as a consequence of postpolygonization by our unique reconstructors. An exact solution can be obtained via a convex hulling process on the preliminary finite fields by means of high-resolution configurations. Our 3D remodeling method using solid-state tessellation has opened the field to wider ranges of complete-gridding plans to achieve matchless enriched reformation capability, which makes our new solidification remeshing of models better than the majority of currently available methods.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Achchhelal Yadav, Arti Bhatia, Sudesh Yadav, Vinod Kumar, Bhupinder Singh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Global food security is challenged by increasing levels of CO〈sub〉2〈/sub〉, O〈sub〉3〈/sub〉 and temperature trough their impacts on production and grain quality of wheat, one of the major C〈sub〉3〈/sub〉 crops and staple food across the world. The present study was conducted to assess the effects of elevated levels of CO〈sub〉2〈/sub〉 (EC; 550 ppm) and tropospheric O〈sub〉3〈/sub〉 (EO; 70 ppb) as well as of combined interactive treatment [EC X EO; ECO] on plant growth, yield and grain quality of two wheat cultivars (HD-2967 and C-306) grown during 2016–17 and 2017–18 using free air ozone and carbon dioxide enrichment (FAOCE) facility under field conditions. Individually, EC, increased leaf area index (LAI; 15.9–28.2%), photosynthetic rate (Pn; 11.4–20.3%) and yield (8.2–20.9%) whereas EO declined LAI (5.1–12.5%), Pn (2.8–11.8%) and yield (2.2–14.2%) over ambient conditions (Amb: 405.2 ppm CO〈sub〉2〈/sub〉 and 30.7 ppb O〈sub〉3〈/sub〉). Under ECO condition, EC increased LAI (2.2–17.1%), Pn (2.8–17.6%) and grain yield parameters (4.4–24.3%) across the cultivars in both years, but reduced the positive effects of EO on quality as compared to Amb. Dilution effect of increased yield under EC condition have reduced total protein, micro- and macro-nutrient concentrations whereas EO increased them notably compared to Amb. Starch in grains increased under EC but reduced under EO as compared to Amb. AOT40, the sum of averaged difference of O〈sub〉3〈/sub〉 h〈sup〉−1〈/sup〉 concentration beyond 40 ppb for 7 hours (31233 ppb h〈sup〉−1〈/sup〉) in FAOCEs rings during the crop growth period led to reduction in average grain yield of HD-2967 and C-306 by 11.6 and 8.5% or by 1.6 and 1.3% yield loss per ppb increase of O〈sub〉3〈/sub〉, respectively. The growth, yield and quality parameters of both wheat cultivars responded similarly but to different extent to all treatments. EC was able to offset the negative effects of EO on yield and yield components only, but not those concerning the quality of grains. To stabilize global food security, precursor gases forming tropospheric ozone must be constrained.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Stephanie Braun-Galleani, Maria-José Henríquez, Darren N. Nesbeth〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have engineered strain BG-10 of the methylotrophic yeast 〈em〉Komagataella phaffii〈/em〉 for use as an effective whole cell biocatalyst. We introduced into the yeast a transgene encoding a 〈em〉Chromobacterium violaceum〈/em〉 ω-transaminase for transcription in response to methanol induction. The strain was then assessed with respect to its growth performance and biotransformation of a fed ketoalcohol substrate to an amino-alcohol. In the resultant strain, BG-TAM, methanol induction did not compromise cell growth. Successful bioconversion of fed substrates to the by-product, acetophenone, indicated transaminase activity in shake flask-cultivated BG-TAM cells. We then used bioreactor cultivation to exploit the high levels of biomass achievable by 〈em〉Komagataella phaffii〈/em〉. In a 900 μL reaction the BG-TAM strain at OD〈sub〉600〈/sub〉 = 1024 achieved up to 0.41 mol mol〈sup〉−1〈/sup〉 (mol〈sub〉product〈/sub〉 mol〈sub〉substrate〈/sub〉〈sup〉−1〈/sup〉) yield on substrate (Yp/s) for production of 1-methyl-3-phenylpropylamine and a space time yield (STY) of 0.29 g L〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉 for production of 2-amino-1,3,4-butanetriol. We have shown that transamination, an important step for bespoke synthesis of small molecule medicines, is biologically realisable using enzymes with a broad substrate range, such as ω-transaminases, within living yeast cells that are fed low-cost substrates for bioconversion.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Farkhondeh Jabari, Behnam Mohammadi-ivatloo, Mousa Mohammadpourfard〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, seawater desalination and power generation units are optimally co-scheduled because of interconnection between electricity and water networks. A typical water-energy hub grid consists of the conventional thermal power plants and the combined water and power (CWP) generating units. In the CWP plants, the waste heat of the flue gases exhausted from the power generation process is utilized for water treatment. If the water and power generation company aims to maximize its daily profit, the electricity price uncertainty will affect the optimum operating point of the generating units. In other words, the fluctuations of the energy prices cause the power generation patterns of thermal and CWP units to change. Hence, this paper implements a robust optimization strategy on water-power nexus model to handle the uncertainty of the electricity price with no need for its probability distribution and membership functions. The lower and upper bounds and the forecasted prices are used for solving the robust mixed-integer non-linear program and making the risk-averse decisions against the uncertainty. It is indicated that the proposed approach is suitable for the price taker water-power cogeneration companies, which seek the optimal schedule of their thermal and CWP units for a certain operating period.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Natalia Hernández-Arango, Valeria Pinto, Deicy Muñoz-Sanchez, Fabiana Lora-Suarez, Jorge Enrique Gómez-Marín〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Methods to detect protozoa are needed for food safety monitoring. We evaluated protocols to recover 〈em〉Giardia spp.〈/em〉 cysts in 〈em〉Brassica oleracea〈/em〉 (cabbage) and 〈em〉Lactuca sativa〈/em〉 (lettuce) and then detection was performed by concentrating with formalin/ether solutions and microscopy or immunofluorescence or DNA amplification via PCR. To evaluate this methodology, 〈em〉G. duodenalis〈/em〉 cysts were inoculated in triplicate (10 cysts) in 35-g samples of lettuce and cabbage. The method obtaining the highest percentage of recovery in cabbage was sulfamic acid solution plus stirring with stomacher (47.7% ± 7.5). For lettuce, the best method was glycine solution plus stirring with stomacher (46.6% ± 5.3). Inter-observer agreement was of 0.99. 〈em〉Giardia〈/em〉 was detected by amplifying specific sequences for the DNA coding SSU rRNA. In 27 lettuce samples and 27 cabbage samples, obtained from supermarkets and street vendors, two lettuce samples (7.4%) and one cabbage sample (3.7%) were positive for 〈em〉Giardia〈/em〉 via PCR assay and were sequenced, determining that they were two of assemblage B and one of lettuce to assemblage E. This method is proposed to detect 〈em〉Giardia〈/em〉 in vegetables by PCR detection, enabling public health authorities to identify genotypes circulating in food, which will help to establish measures that reduce outbreaks of parasitic diseases associated with contaminated food.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Hung Tseng, Henry Small〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantitative analysis of knowledge content of a significant technological innovation is a novel approach to understand the scientific discovery process. Here we describe such an analysis applied to the invention of recombinant DNA technology in the early 1970's. Two focal papers are selected, i.e., Jackson et al., 1972 and Cohen et al., 1973. A knowledge framework called EApc is described to categorize knowledge types and their quantification. The focal papers, along with their reference lists, are used to determine the minimal scientific knowledge necessary for generating the notions central to each focal paper. Attempts are made to trace how each type of knowledge was generated by various research communities. The results are discussed in terms of their potential implications in measuring, evaluating, understanding and managing the scientific research process.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Zheng Zhao, Changbin Chu, Deping Zhou, Zhimin Sha, Shuhang Wu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil nutrient characteristics are key factors that regulate grape growth and fruit quality. To investigate soil nutrient characteristics, 73 typical vineyards in Shanghai suburbs were selected for this study. The impacts of different planting areas, planting ages and grape varieties on soil characteristics were studied. The Agro Services International (ASI) analysis method was adopted to measure the levels of soil nutrients. The results indicated that soil nutrient characteristics varied greatly across the 73 selected vineyards in Shanghai suburbs. Planting area and planting age were the major factors that significantly affected soil nutrient characteristics. However, no significant differences were observed among the 5 major cultivated grape varieties. Significant differences in soil pH were only observed in different planting areas. Soil nutrients in the selected vineyards were mainly at a high level or extra-high level, which means that the current amount of fertilizer in these vineyards exceeds the actual demands of the grapevines and should be reduced. Meanwhile, the intermediate soil organic matter (OM) content indicated that more organic fertilizer should be applied to the soil in these vineyards. Optimized fertilization based on soil nutrient levels plays an essential role in sustaining production resources, increasing economic benefits and improving environmental conditions of vineyards.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Lekan Taofeek Popoola〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study attempted to investigate the use of nanomagnetic activated carbon prepared from walnut shell and rice husk wastes for removal of Cd(II) from aqueous solution via application of ANN and design expert as adsorbent preparation design and optimization tools. The novel adsorbent was characterized using SEM, FTIR, EDS and BET. The result from 2-level factorial design expert revealed 78.58% Cd(II) sorption efficiency could be achieved for adsorbent prepared at optimum calcination temperature, calcination time, SS-RH mixing ratio and magnetite loading of 859.20 °C, 2.32 h, 2.54 and 5.56 wt% respectively. Sensitivity analysis by both proposed methodologies revealed calcination temperature as most influential factor in adsorbent preparation. Average relative errors and R〈sup〉2〈/sup〉 values of 1.2931% and 4.806%; and 0.9967 and 0.9055 obtained respectively for developed ANN model with 4-9-1 architecture and 2-level factorial design expert revealed ANN model as better prediction and optimization tool for Cd(II) sorption using NM-WS-RH-AC. Laboratory analysis revealed presence of –OH, –NH and COO〈sup〉−〈/sup〉 groups on adsorbent surface; presence of Cd(II) after adsorption; change in adsorbent textural and morphological structure after Cd(II) adsorption; and increase in its surface area and average pore diameter due to magnetization. Average relatively stable desorption strength of 62.74% towards Cd(II) was exhibited by adsorbent for four consecutive cycles using 0.1M HNO〈sub〉3〈/sub〉. Prepared adsorbent is effective in removing Cd(II) from solution than commercial activated carbon with economically viable regeneration attribute.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Federica Valeriani, Lory Marika Margarucci, Gianluca Gianfranceschi, Antonello Ciccarelli, Filippo Tajani, Nicolina Mucci, Maurizio Ripani, Vincenzo Romano Spica〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Synthetic fibres are used in place of the natural grass worldwide, for realizing playgrounds, soccer fields and even domestic gardens or recreational structures. An intensive use of artificial turf is currently observed in sports facilities, due to lower costs, higher sustainability in recycling of materials, and advantages related to athletic practice and performance. However, even if chemical and physical risks were studied, the microbiological component was not fully addressed, especially considering a comprehensive evaluation of the microbiota in synthetic vs natural playground surfaces. Here, we investigated the microbial community present on soccer fields, using Next Generation Sequencing and a 16S amplicon sequencing approach. Artificial and natural turfs show own ecosystems with different microbial profiles and a mean Shannon's diversity value of 2.176 and 2.475, respectively. The bacterial community is significantly different between facilities (ANOSIM: R = 0.179; p 〈 0.001) and surface materials (ANOSIM: R = 0.172; p 〈 0.005). The relative abundance of potentially pathogenic bacterial OTUs was higher in synthetic than in natural samples (ANOVA, F = 2.2). Soccer fields are characterized by their own microbiota, showing a different 16S amplicon sequencing signature between natural and artificial turfs.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Morteza Alizadeh, Leila Rezakhani, Mostafa Soleimannejad, Esmaeel Sharifi, Maryam Anjomshoa, Akram Alizadeh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Aims〈/h6〉 〈p〉The aim of this study was to present a new method for removing Sodium dodecyl sulfate (SDS) detergent from decellularized bovine pericardium using vacuum.〈/p〉 〈/div〉 〈div〉 〈h6〉Materials and Methods〈/h6〉 〈p〉The cows’ pericardia were collected and decellularized. The samples were incubated with SDS1% for 48 h at 40 °C. To perform vacuum washing (VW: negative pressure was used to wash and remove detergents), every decellularized tissue was cut in 75mm diameter and fixed via a stainless-steel ring with 60mm diameter in the center of filtration Buchner Funnel which was connected to glass filtration flask The system was connected to a vacuum pump by a hose, and a negative pressure of -100 mmHg was applied for 15 min. Then, the samples were shaken and washed at 40-rpm in 100 ml of distilled water for 45 min. This process was repeated for samples of each group (6 times for sample VW6h, 12 times for sample VW12h, and 24 times for sample VW24h). At the end of every cycle, the effluent was collected to take a sample for SDS measurement. The normal washing (NW) group containing distilled water (NWd) and PBS (Phosphate buffered saline) (NWp) were used to wash and remove detergents. SDS measurements, MTT Assay, histological and tensile test, to compare two methods were used.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉The highest SDS in the effluent was in groups VW12h and VW24h (P ≤ 0.001) and the lowest residual SDS in scaffold was in two groups of VW12h and VW24h (P ≤ 0.001). MTT assay showed that cell survival in the VW12h and VW24h groups was higher than other groups and there' was no significant difference between cell survival in the VW12h and VW24h groups. Histological study showed destruction of tissue in the VW24h group. The results of the tensile test were shown that the native group had the highest module and the lowest amount was the VW24h sample which was reported with P ≤ 0.001 significance for all groups.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusion〈/h6〉 〈p〉VW12h can be used as an effective method for SDS removal from decellularized pericardium which morphologically demonstrated a good structure in ECM.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): M. Dachyar, Teuku Yuri M. Zagloel, L. Ranjaliba Saragih〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The term "Internet of Things" first appeared in publication paper since 2006, describing the paradigm of evolution concept that brought about by the presence of internet technology (Vermesan and Friess, 2015) which is very important in contemporary circumstances. This study conducted an in-depth analysis of the research material written on 26420 papers which focused on the published Internet of Things (IoT) research, starting from the firstly year IoT keyword appeared in 2006 until 2018. The selected paper is a combination of various disciplines and publications which are all indexed by Scopus wherein the article discusses IoT. IoT articles are classified using key attributes in sequence: the methodology used, general knowledge and applied concepts, and various general exploration topics. By using the Scientometrics method, this method will group the overall terms that appear frequently from the Scopus paper database according to keywords, titles, and abstracts. The resulting data is then studied to understand and distinguish trends that occur in the time span along with the general characteristics of the paper, in the mathematics visual scheme. All various issues that are considered in the paper's methodology selection, their studied and services innovations, and continuing discoveries on the characteristics, concepts, and processes applied to IoT success. Although it only involves scopus indexed paper, this study found a remarkable increase in the number of articles on IoT in each category of the paper. This study also reveals the direction of the regular discipline of knowledge. The use of the Scientometrics method makes the analysis able to focus on the movement of characteristics and IoT themes to researcher's direction that has not found at this time, as a comprehensive guide to further research and industry strategy that is more directed on concepts that support the 4th industrial revolution.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Majdah M. Badr〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉An important problem in statistics is to obtain information about the form of the population from which the sample is drawn. Goodness of fit (GOF) tests is employed to determine how well the observed sample data “fits” some proposed model. The well known standard goodness of fit tests; Kolomogorov-Smirnov (KS), Cramer von Mises (CVM) and Anderson-(AD) tests are used for continuous distributions. When the parameters are unknown, the standard tables for these tests are not valid. The complete sample procedures of goodness of fit tests are inappropriate for use with censored samples. The critical values obtained from published tables of the complete sample test statistic are necessarily conservative.〈/p〉 〈p〉In this paper, we obtain the tables of critical values of modified Kolmogorov-Smirnov (KS) test, Cramer-Von Mises (CVM) test and Anderson-Darling (AD) test for the Compound Rayleigh (CR) distribution with unknown parameters in the case of complete and type II censored samples. Furthermore, we present power comparison between KS test, CVM test and AD test for a number of alternative distributions. Applications of the considered distribution to real medical data sets given by Stablein et al. (1981) are presented.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Martínez-Mera Eliana Andrea, Torregroza-Espinosa Ana Carolina, Crissien-Borrero Tito José, Marrugo-Negrete José Luis, González-Márquez Luis Carlos〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study evaluated the concentration and distribution of heavy metals (HM) (Cr, Ni, Pb, Cd, Hg, and Zn) and pesticides (organochlorine and organophosphorus) and the relationship of these pollutants with the physicochemical properties of agricultural soils in an Irrigation District (ID) in Colombia. Soils samples were analyzed for pH, humidity, organic matter, P total, N total, electric conductivity (EC), cation exchange capacity, and texture (% sand, clay and silt). Canonical correlation was used to determined relationship between soil properties and HM. Soil pollution were evaluated with geoaccumulation index (Igeo), contamination factor (CF), degree of contamination (Cdeg) and pollution load index (PLI). The results indicated that, in general, the soils had adequate physicochemical conditions for the establishment and development of crops. The presence of pesticides in the soils was not reported. However, concentrations HM was detected (Zn 〉 Cr 〉 Ni 〉 Pb 〉 Hg 〉 Cd). The soil characteristics (silt, clay, pH and EC) contributed to explain HM concentrations. The Igeo indicated that the soils are heavily contaminated with Hg (3 〈 Igeo〈4). The CF was very high for Hg (〉6). The Cdeg presented moderate to considerable variations (〉6Cdeg〈24). The PLI indicated that the soils are contaminated (1.308). The presence of HM may be associated with the agricultural and quarries activities carried out near the ID. The impact caused by high concentrations of HM can lead environmental, economic and social impacts in the study zone.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Norma Flores-Holguín, Juan Frau, Daniel Glossman-Mitnik〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A methodology based on the concepts that arise from Density Functional Theory (CDFT) was chosen for the calculation of the global and local reactivity descriptors of the Phallotoxin family of fungal peptides. The determination of the active sites for the molecules has been achieved by resorting some descriptors within Molecular Electron Density Theory (MEDT) like the Dual Descriptor and the Parr functions. Phallosacin has been found as the most reactive of the peptides on the basis of the calculated Global Reactivity Descriptors. The pKas of the seven studied peptides were established using a proposed relationship between this property and the calculated Global Hardness. The bioactivity properties of the peptides considered in this study were obtained by resorting to a homology model by comparison with the bioactivity of related molecules in their interaction with different receptors.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Zhiyao Yang, Ming Qu, Omar Abdelaziz, Kyle R. Gluesenkamp〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Liquid desiccant systems (LDS) have recently seen an increase in research interest as they can utilize low-grade heat resources and separate the sensible and latent cooling loads by efficiently removing moisture in the air without cooling it to the dew point. However, simulation and analysis of LDS had remained complex and demanding due to the limited resources of LDS simulation tools. This work presents the new LDS module developed in the Sorption system Simulation program (SorpSim), which is an open-source and flexible platform for steady-state simulation and analysis of various sorption systems. First, the new LDS module containing a finite-difference model and an effectiveness-NTU model for the heat and mass transfer in LDS dehumidifier/regenerator component was introduced. Then the simulation results of the new module were verified using data from the literature. Finally, a case study was carried out in SorpSim where an LDS cycle was built and simulated using the new module. The impacts of design and operating parameters on the simulated LDS performance were investigated. The parametric study revealed that a high source temperature improved moisture removal rate (MRR) but reduced the system coefficient of performance (COP); the COP increased monotonically with the desiccant solution recirculation ratio, while the MRR peaked at a ratio of 85%; and an internal solution heat exchanger with UA of 800 W/K was found to be sufficient for optimal performance under high recirculation ratios. The case study demonstrated the LDS module’s capability to facilitate the analysis of LDS design and operation. The LDS module can be further coupled with other component models in SorpSim to simulate and analyze various liquid-desiccant-based systems.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Mohammad Parhizi, Ankur Jain〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phase change materials (PCMs) are used commonly for thermal energy storage and thermal management. Typically, a PCM utilizes its large latent heat to absorb and store energy from a source. The rate of energy stored (W) and energy storage density (J/m〈sup〉3〈/sup〉) over a certain time period are both important performance parameters of a phase change based energy storage system. While significant experimental research has been carried out to improve thermal conductivity of PCMs, there is a lack of theoretical understanding of how thermal conductivity and other thermophysical properties affect these performance parameters. This paper presents a theoretical heat transfer model to predict the rate of energy storage and energy storage density as functions of PCM thermal properties. Using perturbation method based techniques, expressions for these parameters are derived for two geometries, first for a simplified assumption of constant temperature at the source-PCM interface, and then for a more realistic scenario of time-dependent interface temperature. Results indicate that while increasing thermal conductivity results in improvement in rate of energy stored, the energy storage density does not change for a Cartesian system and actually decreases for cylindrical system. This shows that using a high thermal conductivity PCM may not be ideal when energy must be stored compactly because while this increases the total energy absorbed, it also results in greater rate of melting, which reduces the energy storage density. Results also provide guidelines for material selection for phase change based energy storage systems. For example, a trade-off in the choice between materials of disparate thermal properties is identified in terms of whether the rate of energy stored or energy storage density is paramount. Differences in the performance of Cartesian and cylindrical systems is investigated. Theoretical results presented in this work highlight various performance trade-offs related to the thermal properties of the PCM and help understand the impact of thermal conductivity enhancement on phase change energy storage performance.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Xudong Wang, Daqian Zhang, Xiaojia Wang, Zhiwei Kong, Yali Shao, Baosheng Jin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the increasing thermal input of chemical looping combustion (CLC) reactor, the monitoring and diagnosis of its internal boundary conditions become important issues for operation safety. Based on the discrete heat transfer model of reactor wall, Kalman filter and fuzzy inference were combined as fuzzy inference-based augmented Kalman filter (FI-AKF) and fuzzy inference-based Kalman filter coupled with weighted recursive least squares algorithm (FI-KFW) for the real-time monitoring of CLC reactor. Simulations were carried out to validate the feasibility of these two methods. Under both normal and abnormal conditions, the FI-KFW could exhibited satisfying performances for the internal heat flux monitoring. Number of the measurement points and intensity of measurement noises were changed numerically to investigate their effects on the monitoring results of FI-KFW. Results demonstrated that FI-KFW had strong ability to resist the ill-posedness of the monitoring process and it was capable for the real-time monitoring of the chemical looping combustion reactor, which could offer reliable information for operation diagnosis.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Obindah Gershon, Nnaemeka Emmanuel Ezenwa, Romanus Osabohien〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The study examines the implications of oil price shocks on developing net oil-importing countries. The study considers the casual relationship, impulse response function, and vector decomposition between oil prices and macroeconomic variables using an unrestricted vector autoregressive (VAR) model. In addition, other robust econometric techniques were applied to the time series of oil prices, GDP per capita (GDPC), and energy consumption from 1980 to 2015. Mix results were obtained for the selected African countries - Cape Verde, Liberia, Sierra Leone, and The Gambia. Evidence from the granger test shows that oil prices cause GDPC in Liberia and Sierra Leone. Furthermore, analyses from the VAR model and Impulse response indicate that oil price increase will temporarily increase GDP per capita in the short run for the selected countries. The study recommends policies that can effectively mitigate the adverse effect of the oil price increase.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Bayu Arie Fianto, Hayu Maulida, Nisful Laila〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper investigates the determining factors of non-performing financing in Islamic microfinance institutions (MFIs) in Indonesia. Using logistic regression, the study sample comprises data from 140 clients; 90 with a good financing status and 50 with a poor financing status. The results show that age, gender, occupation, and type of contract influence the non-performance of clients of Islamic MFIs in Indonesia. Probit regression confirmed the results.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Yongming Han, Chenyu Fan, Meng Xu, Zhiqiang Geng, Yanhua Zhong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The production data of complex chemical processes are multi-dimensional, uncertain and noisy, and it is difficult to directly control raw materials consumption and measure the product quality. Therefore, this paper proposes a production capacity analysis and energy saving model using long short-term memory (LSTM) based on attention mechanism (AM) (AM-LSTM). The weights of the results sequence in the hidden layer, which have great influence on final results in the output layer, are calculated by the AM. Then the production prediction model is built using the LSTM to extract features of the input data and multiple time series results of the hidden layer. Compared with the common LSTM, the multi-layer perceptron (MLP) and the extreme learning machine (ELM), the applicability and the effectiveness of the proposed model is validated based on University of California Irvine repository (UCI) datasets. Finally, the proposed model is applied to analyze the production capacity and the energy saving potential of the purified terephthalic acid (PTA) solvent system and the ethylene production system of the complex chemical process. The experimental results verify the practicability and accuracy of the proposed model. Furthermore, the results offer the operation guidance for production capacity improvement through saving energy and reducing the energy consumption.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1359431118343485-ga1.jpg" width="170" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Abdulkhaliq Alazzawie〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Adopting the Cartography research program (Rizzi, 1997, 2001, 2004), the present work investigates the CP layer in Standard Arabic (SA); specifically, the nature and position of topicalized and object focused phrases in the left periphery. The paper also seeks to establish that in fact subjects, like objects and obliques, can also topicalize, the difference being that the pronoun is optionally lexically expressed in subject-topicalization. The ‘Subject’ initial-DP will be treated as a topic located high up in the clausal structure - in the specifier position of the Top node above Foc. Elements in this position fill a special pragmatic sense and discourse role of being presumed, given and identifiable topics rather than an argument or a thematic function.〈/p〉 〈p〉Building on Rizzi's (2004) and Ouhalla's (1997) proposals that generate moved objects and 〈em〉wh〈/em〉-phrases in [Spec, Foc], two focus positions will be posited for SA – one is located immediately above 〈em〉v〈/em〉P and the second is right below TopP. It will be proposed that object movement over the subject is triggered by the [F] feature on Foc and derives the VOS order. Triggered by the higher [F] feature, the raised object and the raised 〈em〉wh〈/em〉-word can raise again to the higher [Spec, Foc]. It is concluded that the position occupied by topicalized DP's differs from that of focused DP's. In particular, SA topics occupy a higher position in the left periphery, namely [Spec, TopP].〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Poushpi Dwivedi, P.K. Mishra, Manoj Kumar Mondal, Neha Srivastava〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nowadays, increasing population, widespread urbanization, rise in living standards together with versatile use of polymers have caused non-biodegradable polymeric wastes affecting the environment a chronic global problem, simultaneously, the existing high energy demand in our society is a matter of great concern. Hence forth, this review article provides an insight into the technological approach of pyrolysis emphasizing catalytic pyrolysis for conversion of polymeric wastes into energy products and presents an alternative waste management technique which is a leap towards developing sustainable environment. Pyrolysis of waste non-biodegradable polymer materials involves controlled thermal decomposition in the absence of oxygen, cracking their macromolecules into lower molecular weight ones, resulting into the formation of a wide range of products from hydrogen, hydrocarbons to coke. Nanocatalyzed pyrolysis is a recommended solution to the low thermal conductivity of polymers, promoting faster reactions in breaking the C-C bonds at lower temperatures, denoting less energy consumption and enabling enhancement in the process selectivity, whereby higher value added products are generated with increased yield. Nanotechnology plays an indispensable role in academic research as well as in industrial applications. Existing reviews illustrate that one of the oldest application field of nanotechnology is in the arena of nanocatalysis. Nanocatalysis closes the gap between homo and heterogeneous catalyses while combines their advantageous characteristics and positive aspects, reducing the respective drawbacks. During the current nanohype, nanostructured catalysts are esteemed materials and their exploration provide promising solutions for challenges from the perspective of cost and factors influencing catalytic activity, due to their featured high surface area to volume ratio which render enhanced properties with respect to the bulk catalyst.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Alaa M.M.A. Mahgoub〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The study of the extent of variability and the order of importance for the impact of environmental factors on species distribution and weed community structure from one region to the other is an interesting research subject. The present study aimed to discuss the issue to give a comparative view with the author's findings about the impact of the prevailing climate, soil type, crop type, crop sustainability and urbanization on species distribution and weed community structure in the coastal farmland and adjacent territories in northwest delta region (Mahgoub, 2019). A new sample area selected and comprised the reclaimed land of El Ballah region in Isthmus of Suez and adjoining farmland east Nile delta. A total of 245 species were recorded. Agglomerative Hierarchical Clustering (AHC) identified four vegetative sociation groups (VSG). The diversity of the four identified VSG or weed communities was evaluated at different levels. Parincipal Component Analysis (PCA) indicated the influence of the five eco factors on species distribution and variability of weed community structure, summarized the relationships among variables and investigated the proximity among samples and how they related to variables. ANOVA followed by Tukey's test were applied twice for the resulted VSG, one depending on soil variables as explanatory variables and the other on sampling site's indicative scores for the five eco factors. The results of ANOVA (R〈sup〉2〈/sup〉, F, P), sample variance (S〈sup〉2〈/sup〉) and other multivariate analyses indicated a different order of importance for the impact of the five eco factors in comparable to the former study denoted above. The soil type was the most impacting factor on species distribution and weed community structure, followed by crop type, crop sustainability, prevailing climate and urbanization, respectively.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Youssef Elrhayam, Ahmed Elharfi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The models of Quantitative Structure-Activity Relationship (QSAR) are indeed useful for understanding the mechanism of chemical modification of wood by the method of acetylation. This study shows that the electrophile index ω in combination with other descriptors, namely LUMO energy, HOMO, hardness (η) and chemical potential (μ), prove their utility in predicting the chemical modification of wood (gain in mass). The QSAR models are developed through use of Multiple Linear Regression (MLR) and Principal Component Analysis (PCA) methods. The statistical results indicate that the multiple correlation coefficient R〈sup〉〈strong〉2〈/strong〉〈/sup〉 = 0.987, R〈sup〉〈strong〉2〈/strong〉〈/sup〉 adjusted = 0.981 and RMCE = 0.012. This shows both the favorable estimation stability and the appropriate predictive power. The results also indicate that there are significant correlations between the weight gain and the highest occupied molecular orbital HOMO. They also show that the chemical potential μ which are useful for modeling the wood modification are characterized by large hydrophobic properties and high electrophilic powers and therefore could be applied effectively in estimating the acetylation of wood. Finally, the developed model shows that cellulose and hemicellulose are mostly affected by the chemical modification of hydroxyl groups.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): B.V. Dharmendra, Shyam Prasad Kodali, B. Nageswara Rao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉There is a need for heavy-duty machining equipment and tooling to minimize chatter due to work-hardening of the INCONEL materials ahead of cutting. Optimum EDM parameters are to be identified to produce quality products of INCONEL800. Modified Taguchi approach is adopted in the multi-objective optimization to identify the optimum peak current, pulse-on-time and pulse-off-time in the nano powder mixed EDM (n-PMEDM) of INCONEL800 with copper electrode for high material removal rate (MRR) and low surface roughness (SR). Empirical relations for MRR and SR are developed easily in terms of the EDM parameters without use of the MINITAB Release-16 software and validated with test results. Test results are found to be within the expected range. It also demonstrates the advantages of opting Taguchi approach to get complete information through few experiments.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Godshelp Osas Egharevba, Omotayo O. Dosumu, Stephen O. Oguntoye, Ngaitad S. Njinga, Samuel Olatunde Dahunsi, A. Abdulmumeen Hamid, Ajay Anand, Zehra Amtul, Priyanka Ujjukuri〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Aims〈/h6〉 〈p〉Plant extracts have long been used for the ethnomedical treatment of diabetes, microbial infections and as a source of antioxidant. This study was aimed at investigating the antidiabetic, antioxidant, and antimicrobial activities of the n-hexane and ethyl acetate extract of 〈em〉Tephrosia bracteolata〈/em〉 leaves (TBL) as associated with the ethnobotanical knowledge of the local people of Nigeria.〈/p〉 〈/div〉 〈div〉 〈h6〉Main methods〈/h6〉 〈p〉The phytochemical composition of the n-hexane and ethyl acetate extract of the leaves of 〈em〉T. bracteolata〈/em〉 were determined following standard procedures in literature, and it's 〈em〉in vitro〈/em〉 inhibitory activities against α-glucosidase enzyme. 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS〈sup〉.+〈/sup〉) and 1,1-diphenyl-2-picrylhydrazyl (DPPH〈sup〉+〈/sup〉) antioxidant activities were also examined. Well diffusion method was employed in evaluating the antimicrobial property of the extracts.〈/p〉 〈/div〉 〈div〉 〈h6〉Key findings〈/h6〉 〈p〉The ethyl acetate extract of 〈em〉T. bracteolata〈/em〉 leaves had the greatest inhibitory effect on α-glucosidase, followed by the n-hexane with IC〈sub〉50〈/sub〉 43.95 μg/ml and IC〈sub〉50〈/sub〉 ˃50 μg/ml respectively. The ethyl acetate also exhibited significant DPPH〈sup〉+〈/sup〉 and ABTS〈sup〉.+〈/sup〉 antioxidant activity with IC〈sub〉50〈/sub〉 of 24.96 μg/ml and 6.48 μg/ml as compared to Ascorbic acid and Trolox (12.24 μg/ml and 5.91 μg/ml) respectively. The zones of inhibition of the ethyl acetate extract of 〈em〉T. bracteolata〈/em〉 leaves ranges from 10 – 25 mm at a concentration of 6.25–200 mg/ml, and it showed a greater antibacterial activity than the n-hexane extract, having a zone of inhibition from 10 – 20 mm at concentration of 12.5–200 mg/ml when compared to the standard Gentamycin. Similarly, the ethyl acetate extract of 〈em〉T. bracteolata〈/em〉 showed a better anti fungi activity at concentration range 12.5–200 mg/ml than the n-hexane extract at concentration range of 25–200 mg/ml with reference to Tioconazole. These results indicated for the first time that the ethyl acetate extract of 〈em〉T. bracteolata〈/em〉 leaves extracts exerted potent inhibitory effects against α-glucosidase, actively scavenge DPPH〈sup〉+〈/sup〉 and ABTS〈sup〉.+〈/sup〉 free radicals and successfully inhibits the proliferation of Gram positive and Gram negative microorganism.〈/p〉 〈/div〉 〈div〉 〈h6〉Significance〈/h6〉 〈p〉TBL is an important source of antidiabetic, antimicrobial and antioxidant agent.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Florencia Cattaneo, Julieta Roco, Gabriela Alarcón, María Inés Isla, Susana Jeréz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Aims〈/h6〉 〈p〉〈em〉Prosopis alba〈/em〉 flour is a natural source of nutrient and phytochemicals with potential effects on cardiovascular risk factors. The aim of this work was to examine the effects of dietary supplementation with 〈em〉Prosopis alba〈/em〉 seed flour (Pr-Feed) on a high fat diet (FD)-induced rabbit model of metabolic syndrome.〈/p〉 〈/div〉 〈div〉 〈h6〉Main methods〈/h6〉 〈p〉Rabbits were separated in four groups: fed regular diet (CD); CD supplemented with Pr-Feed; fed on 18 % FD; FD supplemented with Pr-Feed. All diets were administrated for 6 weeks. After the feeding period body weights, mean blood pressure, heart rate and visceral abdominal fat (VAF) were determined; glucose tolerance test (GTT) was performed; total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, triglycerides (TG), fasting glucose (FG), aspartate amino transferase, alanine amino transferase, bilirubin and creatinine were measured in serum. Abdominal aorta was excised and vascular function was assessed by acetylcholine relaxation and contractile response to KCl, norepinephrine and angiotensin II.〈/p〉 〈/div〉 〈div〉 〈h6〉Key findings〈/h6〉 〈p〉Phytochemical analyses showed that the main compounds of Pr-Feed were apigenin C-glycosides. FD increased VAF, FG, TG, reduced HDL-cholesterol and induced abnormal GTT. Pr-Feed addition to FD did not modify these alterations. Aortic rings from rabbits fed on FD exhibited an impaired relaxation-response to acetylcholine and increased agonist vasoconstrictor responses. Pr Feed-supplemented FD improved the response to acetylcholine, and prevented the increase of the contractile response to KCl, norepinephrine and angiotensin II.〈/p〉 〈/div〉 〈div〉 〈h6〉Significance〈/h6〉 〈p〉Results suggest that dietary supplementation with Pr-Feed, rich in apigenin C-glycosides, has vascular protector properties and could be used to prevent vascular alterations characterizing the metabolic syndrome.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Mahmoud O. Hassan, Yasser M. Hassan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Human impact in newly urbanized deserts creates new environments that may favor the establishment/dominance of certain plant species. In this study, we showed how the human activities during desert urbanization do affect distribution, composition and diversity of plant species in a new urban ecosystem. In a field study during 2015–2016 and 2017–2018 growing seasons, we investigated these vegetation criteria in three new habitats created recently due to human manipulations in addition to the old habitat of such area (i.e. the desert). We also compared vegetation criteria comprising the floristic cover, composition and diversity between the desert locations inside and on the outskirts of the city. The detrended correspondence analysis (DCA) successfully separated the different habitats studied. Besides, the floristic composition and diversity were significantly varied amongst these habitats. The canonical correspondence analysis (CCA) revealed an apparent correlation between floristic composition and soil criteria across the study area. For the desert vegetation, the cover values of both 〈em〉Tamarix nilotica〈/em〉 and 〈em〉Zygophyllum coccineum〈/em〉, in addition to the whole diversity indices, were significantly suppressed in the desert fragments inside the newly constructed city in comparison with their cover in the desert adjacent to it. Moreover, the cover of both species was significantly declined in 2018 compared with their cover in 2015. On converse, the covering areas of 〈em〉Phragmites australis〈/em〉 and 〈em〉Bassia indica〈/em〉 were increased after intensive constructions in 2018. These results suggest that the human activities and, consequently, urbanization may influence plant life in newly urbanized desert ecosystems, leading to dispersal of new species and destruction of plant cover in some parts of the desert. Efforts and conservation strategies should be devoted to save the desert species that are vulnerable to elimination due to expansion of urbanization.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Dalal Z. Husein, Reda Hassanien, Mostafa F. Al-Hakkani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The release of Non-Steroidal Anti-Inflammatory drugs (NSAIDs) such as Ibuprofen (Ibu), Naproxen (Nab) and Diclofenac (Dic) to the aquatic system cause serious environmental problems. In this study, green-synthesized copper nanoparticles (Cu NPs) have been used as nano-adsorbent for the removal of Ibu, Nab, and Dic from wastewater samples. Formation of Cu NPs was confirmed by different analytical techniques. The adsorption parameters such as temperature, pH, adsorbate concentration, adsorbent dose and contact time were studied. The best removal results were obtained at these conditions: temperature 298 K, pH = 4.5, 10.0 mg Cu NPs, 60 min. At these conditions, the removal percentage of Ibu, Nap, and Dic were found to be 74.4, 86.9 and 91.4% respectively. The maximum monolayer adsorption capacities were calculated as 36.0, 33.9 and 33.9 mg/g for Dic, Nap, and Ibu respectively. The kinetic studies conducted that the sorption process obeyed the second order kinetic model, while the thermodynamic results revealed that the adsorption process was spontaneous, endothermic (+23.8, +40.8 and +38.3 kJ/mol for Ibu, Nap and Dic respectively). The results revealed that green-synthesized copper nano-adsorbent may be used for the removal of the anti-inflammatory drugs from real wastewater efficiently.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Andrea Carpentieri, Angelo Sebastianelli, Chiara Melchiorre, Gabriella Pinto, Marco Trifuoggi, Vincenzo Lettera, Angela Amoresano〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The biomolecular characterization of edible products is gaining an increasing importance in food chemistry. The characteristic aroma or bouquet of a wine is the result of complex interactions of volatile molecules and odor receptors. Its characterization is the subject of many different studies, aimed at the development of new methods to be used for the discovery of frauds and for the typization of Protected Designation of Origin (P.D.O.) or Protected Geographic Indication (P.G.I.) wines.〈/p〉 〈p〉We previously outlined the proteomic profile of three cultivars of 〈em〉Vitis vinifera〈/em〉 from South Italy (Campania) used for white wine production (Fiano, Greco and Falanghina) during the ripening. In this work, we present a mass spectrometry based study aimed at obtaining the profile of volatiles on the same samples using solid phase micro extraction coupled to gas chromatography.〈/p〉 〈p〉We demonstrated that some of the main constituents of aroma (namely terpenes, alcohols, aldehydes, etc.) were characteristic of certain grapes and absent in others.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): N.K. Udaya Prakash, N. Sripriya, K. Gowtham, S. Suresh, B. Sampathkumar, S. Bhuvaneswari〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Diwali is celebrated widely in Asian countries, with a custom of firing crackers. Crackers pollute the environment with noise, particulate matter and chemicals. There are reports on the variation of particulates during firing crackers but none on airborne microbes. The present study was conducted to know the impact of fire crackers on airborne microflora. The air samples were collected 3 days prior to Diwali, on Diwali and 3 days after Diwali during the year 2017 at 15 different areas in Chennai, India. Andersen N-6 viable particle air sampler was exposed with petridishes containing nutrient agar and potato dextrose agar for the isolation of bacteria and fungi respectively. An average of 1,904 ± 2.5 CFU/m〈sup〉3〈/sup〉 of bacteria recorded prior Diwali was reduced by 53.23% on Diwali and increased by 27.37% after Diwali. This reduction on Diwali is attributed to the exposure of bacteria to chemicals emitted by the crackers. For fungi, an average of 235.57 ± 1.67 CFU/m〈sup〉3〈/sup〉 was recorded prior Diwali, with an increase of 78.5% on Diwali. The increase in fungal count might be due to the release of spores by ground crackers. The study shows that bacteria are susceptible to the chemicals emitted by fire crackers when compared with fungi.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Simon Svanborg Kjeldsen, Erhard Trillingsgaard Næss-Schmidt, Gunhild Mo Hansen, Jørgen Feldbæk Nielsen, Peter William Stubbs〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Blood flow restriction training (BFRT) has been proposed for elderly and clinical populations with weakness. Before being used in these populations it is important to understand the neurological effects of, and subject perceptions to, BFRT. Seventeen healthy subjects were recruited and performed 2 experimental sessions, BFRT and training without blood flow restriction (TR-only), on separate days. Four sets of concentric/eccentric dorsiflexion contractions against theraband resistance were performed. Surface electromyography of the tibialis anterior was recorded during exercise and for the electrophysiological measures. At baseline, immediately-post, 10-min-post and 20-min-post exercise, motor evoked potentials (MEPs) from single pulse transcranial magnetic stimulation (TMS), paired-pulse TMS with interstimulus intervals of 2-ms (SICI) and 15-ms (ICF), and the M-max amplitude were recorded in the resting TA. Following training, subjects provided a numerical rating of the levels of pain, discomfort, fatigue, focus and difficulty during training. Muscle activation was higher in the last 20 contractions during BFRT compared to TR. There was no difference (time × condition interaction) between BFRT and TR for single-pulse MEP, SICI, ICF or M-max amplitude. There was a significant main effect of timepoint for single-pulse MEP and M-max amplitudes with both significantly reduced for 20-min-post exercise. No reductions were observed for SICI and ICF amplitudes. Taken together, BFRT and TR-only were only different during exercise and both regimes induced similar significant reductions in M-Max and MEP-amplitude post-training. Due to the lack of changes in SICI and ICF, it is unlikely that changes occurred in cortical sites related to these pathways. The increased surface electromyography activity in the last 20 contractions, indicate that the training regimes are different and that BFRT possibly induces more fatigue than TR. As such, BFRT could be used as an adjunct to conventional training. However, as subjects perceived BFRT as more painful, difficult and uncomfortable than TR-only, people should be selected carefully to undertake BFRT.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Andualem Merga, H.C.Ananda Murthy, Enyew Amare, Kalid Ahmed, Eshetu Bekele〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electrical porcelain insulator was fabricated from local ceramic raw materials, Bombowha kaolin/clay, Arero feldspar and Arero quartz available in Ethiopia. The raw materials mineralogy, chemical composition, and thermal properties were characterized by using x-ray diffractometer (XRD), atomic absorption spectrometer (AAS) and thermogravimetry (TGA), respectively. Plasticity of clay was determined according to Atterberg plasticity test. Based on the raw materials chemical composition, five different porcelain insulator test bodies were prepared at firing temperature of 1000 °C, 1100 °C, 1200 °C and 1300 °C. Water absorbance, apparent porosity, bulk density, dielectric strength and microstructure of fired porcelain insulators were studied as a function of firing temperature. The XRD and AAS results revealed that in Bombowha clay, kaolinite mineral was found to be a major mineral constituent with appreciable silica (46.84 wt%) and alumina (36.74 wt%) content with moderate plasticity (PI = 19–21%). The Arero feldspar belongs to anorthoclase feldspar minerals with less alkali content (Na〈sub〉2〈/sub〉O + K〈sub〉2〈/sub〉0) of 〈7wt %. Among the tested porcelain insulator bodies, the test body with composition of 45% kaolin, 45% feldspar and 10 % quartz exhibited superior properties of having a water absorbance of 0.010%, porosity of 0.088%, density of 2.466 g/cm〈sup〉3〈/sup〉, dielectric strength of 8 Kv/mm at firing temperature of 1300 °C with mullite and quartz phase embedded in sufficient glassy phase. Therefore, the experimental result confirmed that standard porcelain insulator can be fabricated from locally available ceramic raw materials (clay and quartz) in Ethiopia at optimized condition.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Sabino Caputo, Federico Millo, Giulio Boccardo, Andrea Piano, Giancarlo Cifali, Francesco Concetto Pesce〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper investigates the potential of coated pistons in reducing fuel consumption and pollutant emissions of a 1.6 l automotive diesel engine. After a literary review on the state-of-the-art of the materials used as Thermal Barrier Coatings for automotive engine applications, anodized aluminum has been selected as the most promising one. In particular, it presents very low thermal conductivity and heat capacity which ensure a high “wall temperature swing” property. Afterwards, a numerical analysis by utilizing a one-dimensional Computational Fluid Dynamics engine simulation code has been carried out to investigate the potential of the anodized aluminum as piston Thermal Barrier Coating. The simulations have highlighted the potential of achieving up to about 1% in Indicated Specific Fuel Consumption and 6% in heat transfer reduction. To confirm the simulation results, the coated piston technology has been experimentally evaluated on a prototype engine and compared to the baseline aluminum pistons. Despite the promising potential for Indicated Specific Fuel Consumption reduction highlighted by the numerical simulation, the experimental campaign has indicated a slight worsening of the engine efficiency (up to 2% at lower load and speed) due to the slowdown of the combustion process. The primary cause of these inefficiencies is attributed to the roughness of the coating.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Zilong Wang, Hua Zhang, Binlin Dou, Guanhua Zhang, Weidong Wu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Heat storage tanks are one of the key components in solar thermal utilisation systems. In this study, the effect of the inlet stratifier on the thermal stratification in a heat storage tank with phase-change materials (PCMs) was investigated. A heat storage tank with a volume of 60 L and aspect ratio of 1.68 was developed based on the phase-change temperature of 331.15 K for sodium acetate trihydrate. The thermodynamic characteristics of the heat storage tank were measured at an initial temperature of 353.15 K and inlet water temperature of 278.15 K. Moreover, a computational fluid dynamics (CFD) model of the heat storage tank was established to simulate the discharge process. In addition, the CFD model was verified with experimental data. The impact of the PCM position on thermal stratification was thoroughly analysed for various flow rates. Furthermore, performance parameters including the Fill Efficiency (FE), Richardson number (Ri), and MIX number were considered. The results show that the equalizer enhances the thermal stratification effectively in the phase-change heat storage tank and stabilises the heat output characteristics of the water tank. Furthermore, in the water discharge process (t* = 0.1–0.7), the distances between the isothermal surfaces (279.15 K) and isothermal surfaces (352.15 K) in PCM4, PCM3, PCM2, and PCM1 increase by 6.56, 7.2, 8.98, and 12.34 cm, respectively. Thus, the mixing of hot and cold water strengthens with higher PCM position, which improves the thermal stratification in a heat storage tank. The half-life of the PCMs (melting rate reaches 50%) is prolonged with increasing inlet flow rate. For an inlet flow rate of 1 L/min, the half-life of PCM4 is t* = 0.5. For an inlet flow rate of 5 L/min, the half-life of PCM4 is t* = 0.95. Moreover, the simulated results of the FE and Ri are slightly higher than the experimental values, whereas the simulated MIX number results are below the experimental values. Finally, the simulated and experimental root mean-squared error results increase with lower PCM positions and increasing inlet flow rates.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Y.H. Diao, L.L. Yin, Z.Y. Wang, Y.H. Zhao, L. Liang, F.W. Bai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present study, the thermal performance of a latent heat thermal energy storage device based on flat miniature heat pipe arrays with straight rectangular fins during the charging process is numerically investigated using porous media to reduce computational resources and time. Air is selected as the heat transfer fluid (HTF). The influence of a thermal storage unit (TSU) with one heat transfer component (HTC) on the melting rates of the phase change material (PCM) is simulated at different inlet temperatures and flow rates of HTF. The heat transfer between two HTCs that form a tandem is analyzed and compared, and the effect of different arrangements of the two HTCs on the charging process is then studied. Results indicate that the inlet temperature and the volume flow rate of the TSU influence the charging process. The average outlet temperature and charging power, which grow in a power function relationship with the volume flow rates, increase linearly with the inlet temperatures. The average charging power of the HTF through HTC-2 is reduced by approximately 63.71% compared with HTC-1 when the two HTCs form a tandem. The average charging power of the TSU with two HTCs connected in tandem is higher than that of the parallel TSU at the same inlet temperature and volume flow rate.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Bruno Marcotte, Michel Bernier〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents an experimental validation of a thermal resistance and capacitance (TRC) model for double U-tube boreholes with two independent circuits. In the TRC model, the borehole cross-section is divided into four quadrants each with two nodes representing the fluid and the grout, respectively. Ground heat transfer is evaluated in each of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.svg"〉〈mi〉n〈/mi〉〈/math〉 vertical sections using the infinite cylindrical source analytical solution with appropriate temporal superposition. Finally, internal tube-to-tube and tube-to-borehole thermal resistances are evaluated with the multipole method. The TRC model is validated against results obtained using a small-scale borehole (90.39 cm long with a 9.45 cm diameter) positioned in a sand tank of known properties. The borehole is made of ceramic which enabled the precise positioning of thermocouples at the mid-height cross-section. Data are acquired at a high frequency (1 s) to capture transient effects. In the first set of results obtained for a quasi-steady state, isotherms over the mid-height cross-section compare favorably well with the ones obtained using the multipole method. In the other two tests, the borehole is subjected to varying inlet (flow rate and temperature) conditions. It is shown that the TRC model is in good agreement with the experimental data except when there is a severe steep change in inlet temperature or when there is no flow.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Taehoon Kim, Donghwan Kim, Sungwook Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In engine simulation, coarse mesh size is usually used to analyze a variety of cases utilizing chemistry which consists of many species and reactions. However, it is difficult to predict spray morphology exactly with coarse mesh. In this study, a model to predict structure deforming flash boiling spray even for the coarse mesh has been developed. A flash breakup model combined with a modified version of a gas-jet model was utilized to analyze propane flash boiling spray. The gas-jet direction was calculated by averaging the directions of spray from each nozzle. A high-velocity region near the axis of gas-jet flow confined the plumes to form a single plume. Gasoline spray was analyzed to determine proper Kelvin-Helmholtz-Rayleigh-Taylor (KH-RT) model constants. Gasoline spray characteristics such as spray tip penetration and morphology were captured using the final model constants. Using the KH-RT model constants, the flash breakup model was validated for propane flash boiling spray. Sauter mean diameter (SMD) of simulation and experiment showed similar results. However, spray morphology could not be captured by the simulation using only the flash breakup model. A modified gas-jet model was applied to the simulation along with the flash breakup model to improve spray morphology. Using the modified gas-jet and flash breakup models, spray structure penetrating through the central axis was successfully predicted and this resulted in a better spray tip penetration prediction. SMD trend depending on ambient pressure was captured and maximum error between experimental and simulation results was 11%.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Ruikang Wu, Yiwen Fan, Tao Hong, Hao Zou, Run Hu, Xiaobing Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Heat removal of high-power electronic devices has become the bottleneck that restricts the working performances. For ultrahigh heat flux density, even a thin layer of thermal interface material will dominate the temperature rise along the whole heat dissipation path. The existing liquid cooling only consider the cooling of the top surface of the electronic devices/chips, causing insufficient utilization of the cooling potential. In this paper, an immersed jet array impingement cooling device with distributed returns was designed, fabricated, and tested. In the proposed cooling device, the chip is immersed in the coolant and the coolant is ejected onto all the immersed surface of the electronics through the impinging jets, enabling to provide body cooling for high-power electronics. To prevent the jet interference between adjacent jets, distributed extraction returns were set between the adjacent jets for coolant to exit the impingement domain without flowing past the surrounding jets. The measured average temperature of the high-power chip with input heat power 550 W and flow rate 1000 ml/min is 77.0 °C, where the effective heat flux is 110 W/cm〈sup〉2〈/sup〉, and the inlet coolant temperature is maintained to be 40 °C. The average temperature of the high-power chip under the input heat power of 800 W (160 W/cm〈sup〉2〈/sup〉) is 78.7 °C with the flow rate reaching 2000 ml/min. The effective heat transfer coefficient of 41,377 W/m〈sup〉2〈/sup〉·K in maximum was achieved. The present body cooling is expected to provide high heat removal ability and be used for ultrahigh heat flux density electronics.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Soukhyarani Gopal Nayak, Boja Poojary〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pursuing our recent interest regarding the antimicrobial activity of Schiff bases derivatives, we have synthesized a series of 6-(substitutedphenyl)-〈em〉N'〈/em〉-((〈em〉E〈/em〉)-(substitutedphenyl)methylidene)-2-methylpyridine-3-carbohydrazides (〈strong〉5a-n〈/strong〉) and evaluated their antibacterial activity. Structures of these compounds were confirmed by standard studies of FTIR, 〈sup〉1〈/sup〉H NMR, 〈sup〉13〈/sup〉C NMR, MS and elemental analysis. Antibacterial activity of synthesized molecules was tested against Gram-positive (〈em〉S. aureus〈/em〉 and 〈em〉E. faecalis〈/em〉) and Gram-negative (〈em〉E. coli〈/em〉 and 〈em〉P. aeruginosa〈/em〉) bacterial strains. Synthesized compounds showed good antibacterial activity at a lower concentration than standard. Most of the compounds (〈strong〉5a〈/strong〉, 〈strong〉5c〈/strong〉, 〈strong〉5i〈/strong〉, 〈strong〉5j〈/strong〉 and 〈strong〉5n〈/strong〉) are potent against all the tested bacterial strains with MIC values ranging from 1.56-12.5 μg/mL.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Mohamed Hawashi, Ali Altway, Tri Widjaja, Setiyo Gunawan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cassava leaves are a crucial source of alternative protein resources for both humans and livestock in developing societies in African and Asian countries that do not have easy access to available protein sources. Hence, cassava has the capacity to promote the economic development of these countries and provide food security. However, it has some disadvantages due to the anti-nutrient compounds present in its tissues, which limits the nutritional value of cassava leaves. Thus, proper processing of cassava leaves is essential in order to reduce the anti-nutrients to a safer limit before utilization. This study focuses on reducing the tannin content of cassava leaves during solid-state fermentation using 〈em〉Saccharomyces cerevisiae〈/em〉. In addition, the Box-Behnken design of the Response Surface Methodology was applied to optimize various process parameters, such as carbon concentration, nitrogen concentration, moisture content, and incubation time for maximum reduction of tannin content in cassava leaves. A quadratic model was developed for the reduction of tannin content, which resulted in a perfect fit of the experimental data (p 〈 0.01). The optimal conditions were found at 1.4% (w/w) of carbon concentration, 0.55% (w/w) of nitrogen concentration, 57% (v/w) moisture content, and an incubation time of 96 h. The minimum tannin content obtained under these conditions was 0.125%, which indicated a reduction of 89.32 % in tannin content. Conversely, the protein content was increased with a further increase in fermentation time from 24 to 96 h (from 10.08 to 14.11–16.07 %). Furthermore, the ability of 〈em〉Saccharomyces cerevisiae〈/em〉 to produce tannase under solid-state fermentation of cassava leaves was also studied. The maximum yield was obtained with an enzyme activity of 0.53 U/gds after 72 h of incubation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Paula Valentina Polania-Guzmán, Juan Fernando Vélez-García〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The northern tamandua (〈em〉Tamandua mexicana〈/em〉) is a xenarthran mammal with a distribution from Mexico to Peru. This species arrives to wildlife care centres due to illegal trafficking and attacks by domestic dogs, both of which are situations where the northern tamandua's thoracic limbs (forelimbs) can be affected. As such, it is necessary to have anatomical studies that allow us to perform better medical and surgical procedures. Among these, studies about the musculoskeletal system also aid in the muscular reconstructions of extinct species. The aim of this study was to characterize the craniolateral muscles of the forearm in 〈em〉Tamandua mexicana〈/em〉 and compare them with other Xenarthrans to determine their gross adaptations. Six dead specimens were used, and none were sacrificed for the purpose of this investigation. In five specimens, arterial repletion was done. Four were fixed with 10% formaldehyde and 5% glycerin, and two were dissected in fresh. All were dissected in the Veterinary Anatomy Laboratory of the Universidad del Tolima. The weights of the muscles from seven forearms were taken and divided in three functional groups for comparison with non-parametric statistics. Two muscular groups were found: one superficial formed by the brachioradialis, brachioradialis accesorius, extensor carpi radialis, extensor digitorum communis, extensor digitorum lateralis and extensor carpi ulnaris; and one deep muscular group formed by the supinator, extensor digiti III et IV, abductor digiti I longus, and extensor digiti I et II. They were supplied by different branches of the cranial interosseous, transverse cubital and superficial brachial arteries, which had the shape of 〈em〉rete mirabile〈/em〉; and all muscles were innervated by the deep branch of the radial nerve. The presence of the brachioradialis accesorius muscle in this species allows its hand to remain in semi-supination when it is mobilized in a quadrupedal manner. It must also support elbow flexion together with the action of the brachioradialis and the extensor carpi radialis muscles. All the antebrachial digital muscles sent tendons for the digit III making it the most functional for different grip activities such as climbing trees and searching for its food, however, the most strength was directed to supination and carpal extension, and therefore also to the flexion of the elbow.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): U.G. Spizzirri, G. Carullo, L. De Cicco, A. Crispini, F. Scarpelli, D. Restuccia, F. Aiello〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tea (〈em〉Camellia Sinensis〈/em〉) is one of the most popular drink, consumed as infusion or bottled ready to drink beverages. Although tea leaves contain many antioxidants compounds, after processing they can drastically decrease, sometimes up to a full degradation, as in the case of catechin, a very healthy flavan-3-ol. In this context, the synthesis of a cocrystal between (+)-catechin and L-(+)-ascorbic acid, was proved to be a useful strategy to make a new ingredient able to ameliorate the antioxidant profile of both infusions and bottled teas. The obtained cocrystal showed a three-fold higher solubility than (+)catechin and its formation was elucidated unambiguously by FT-IR, thermal (DSC) and diffraction (PXRD) analyses. Antioxidant characteristics of the samples were evaluated by colorimetric assays. As expected, infusions showed much better antioxidant features than ready-to-use lemon and peach teas. The same trend was confirmed after the addition of the cocrystal at two concentration levels. In particular, supplementation at concentration of 2 mg mL〈sup〉−1〈/sup〉 improved the bottled tea antioxidant values to the level showed by the not-added infusion tea.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Ekarat Tangsiriratana, Wanwisa Skolpap, Robert J. Patterson, Kobsak Sriprapha〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a micro-encapsulated phase change material (PCM) was composed of sugarcane wax−Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉composite as the core material and gelatin−gum Arabic as the polymer shell materials prepared by complex coacervation. The thermal behavior of solar panels integrated with this encapsulated PCM (EPCM) was investigated. The heat storage-dissipation performance and thermal stability of the sugarcane wax−based composite PCM layer with the heat capacity of 2.86 J/g·°C was influenced by its thickness. Increasing the composite PCM layer thickness from 4 mm to 7 mm could lower the module's front-facing glass temperature by 4% resulting in enhanced the photovoltaic power generation by 12% at the peak, because of the temperature storage ability of the composite PCM. Moreover, the thermal conductivity of the microencapsulated sugarcane wax was calculated using a steady-state one-dimensional energy balance equation. The thermal conductivities estimated across the composite PCM layer depth were found to be temperature dependent. A nonlinear regression of the power law thermal conductivity model gave a good agreement with the observed EPCM-surface temperatures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Sulayman T. Balogun, Umar K. Sandabe, Kenneth O. Okon, Ayodele O. Akanmu, Fatai A. Fehintola〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The study re-visited malaria burden and pre-hospital medication among malarious subjects in Maiduguri, Northeast Nigeria. A total of 1,657 febrile subjects were screened for malaria by microscopy at two health institutions. Giemsa-stained blood smears were examined for parasitaemia and gametocytaemia; and parasite density (PD), gametocyte density (GD) and gametocyte sex ratio (GSR) were determined. The mean age of the 1,657 subjects was 27.5 ± 12.2 years and 7.8% (130/1,657) of the subjects aged 〈5 years. Sex distribution showed 47.0% (778/1,657) males and 53.0% (879/1657) females. Parasitaemia was recorded in 22.6% (375/1,657) with geometric mean PD of 8,925 (320–275,000) parasites/μl blood. The prevalence of parasitaemia was highest among subjects 〈5 years (χ〈sup〉2〈/sup〉 = 401.1; df = 5; p 〈 0.0001) and in August and September (χ〈sup〉2〈/sup〉 = 406.9; df = 11; p 〈 0.0001). Prevalence of gametocytaemia was 12.8% (48/375) with geometric mean GD of 109 (8–464) gametocytes/μl blood. The prevalence was higher in dry (16.5%, 29/176) than wet (9.5%, 19/199) months (χ〈sup〉2〈/sup〉 = 4.0; df = 1; p = 0.045). The weighted mean GSR was 0.4 ± 0.1 with highest value in March (0.7 ± 0.2). Pre-hospital medication was recorded in 74.1% (278/375) of the subjects with parasitaemia. Analgesics (51.7%; 194/375) accounted for the highest proportion of drug consumed while 9.3% (35/375) of the subjects took antimalarial drugs. Malaria persisted in Maiduguri especially among subjects 〈5 years during wet months and pre-hospital medication is a common practice. These findings could serve as guide for policy decision that could contribute to effective treatment and control of malaria in the region.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Manoj Kumar, Debashis Panda, Suraj K. Behera, Ranjit K. Sahoo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a major component of cryogenic turboexpander, the design and performance estimation of a radial inflow turbine determines the effectiveness of the system. To explore the performance, this paper focuses on to investigate the effect of mass flow rate and operating temperature on isentropic efficiency, temperature drop, enthalpy drop, pressure variation, and power output of a cryogenic turboexpander. Firstly, the mean-line design of a radial inflow turbine is conducted by considering different loss models. Sobol sensitivity analysis is performed to identify the major geometrical parameters which have a significant effect on the performance of the turbine. Based on the geometrical data sets, an 〈em〉ANN〈/em〉 and 〈em〉ANFIS〈/em〉 models are developed to predict the ranges in which maximum efficiency of the turbine is obtained with minimum losses. The designed turbine is validated with available data in the literature. Secondly, an experimental set-up with extended measuring points for data collection is developed to investigate the performance of a turboexpander at cryogenic temperature. A detailed experimental analysis is carried out to compare the temperature drop, isentropic efficiency, and power output of the turboexpander for mass flow rate in the range of 0.03–0.08 kg/s and the inlet temperature of 130, 140, and 150 K. It is noticed that the highest temperature drop is obtained for the inlet temperature of 150 K. Thirdly, based on the experimental data, an 〈em〉ANN〈/em〉 and 〈em〉ANFIS〈/em〉 model is developed to predict the optimal range in which the turboexpander have maximum isentropic efficiency and temperature drop. The results deduce some valuable experimental data and also accumulate the design methodology of radial inflow turbine for cryogenic applications.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Kaswar Ali Al-Ameri, Shohel Mahmud, Animesh Dutta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work proposes a new configuration of solar still system and includes three experimental comparative studies on a 17 cm high longitudinal distillation unit with one distillation partition. The study targets to figure out the optimum conditions that maximize the productivity of the distillation partition. Also, the work includes determining the amount of the rejected waste energy from the unit with respect to the input energy for the optimum case obtained in the study. The investigated comparative cases include gravitational effect vs. Capillary effect of brackish water flow in the distillation partition wick, the performance when the unit is insulated vs. uninsulated, and using single wick vs. double wick layer inside the distillation partition. The work was conducted indoor, and electrical power (30 W, 50 W, 70 W, 90 W, and 110 W) was supplied to the unit separately. The results show that the gravitational brackish water flow, insulating the unit with 1″ thickness styrofoam, and using double cotton wick layer are the optimum operating conditions that maximize the productivity of the distillation partition. Under these conditions and when 110 W is supplied inside the distillation unit, the distillation efficiency of the unit is 15.64%, the distillation partition efficiency is 16.48%, and the heat supply efficiency of the unit is 19.61%. Also, the study proves that the distillation efficiency of the unit, the distillation efficiency of the distillation partition, and the efficiency of heat supply of the unit increases with increasing the input power to the unit.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Xiao Qian, Dongji Xuan, Xiaobo Zhao, Zhuangfei Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The excessively high temperature of lithium-ion battery greatly affects battery working performance. To improve the heat dissipation of battery pack, many researches have been done on the velocity of cooling air, channel shape, etc. This paper improves cooling performance of air-cooled battery pack by optimizing the battery spacing. The computational fluid dynamics method is applied to simulate the flow field and temperature field of the battery pack for different battery spacing. The battery spacing and corresponding CFD simulation outputs (maximum temperature and temperature difference) are used to train the Bayesian neural network. Compared with CFD simulation results, the relative errors are 0.08% and 3.2%. With this neural network model, the optimal battery spacing arrangement is found which is [17,24,22,0.22,0.23,0.176,0.176] and the temperature difference and the maximum temperature of the batteries are respectively 5.986(K) and 300.511(K). The results show this neural network model can accurately describe the relationship between the battery spacing and the battery temperature. This optimization process represents an effective and time-saving method to design the battery spacing distribution to improve the cooling performance of battery pack.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 162〈/p〉 〈p〉Author(s): Evaldas Greiciunas, Duncan Borman, Jonathan Summers, Steve J. Smith〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A Concept Heat Exchanger (HE) design manufactured using the Additive Layer Manufacturing (ALM) technique Selective Laser Melting (SLM) is proposed and numerically evaluated. It is composed of a HE corrugation which introduces inter-layer flow conduits between the parallel HE layers of the same fluid. These pathways are provided by hollow elliptical tubes which serve several functions: to disturb the flow to promote heat transfer, to provide additional heat transfer area and to minimise flow maldistribution inside the HE core. The corrugation is incorporated into a counter-flow prototype HE unit model meaning to exploit the installation volume and design freedom made possible via ALM. Three Computational Fluid Dynamics (CFD) models are utilised to evaluate the performance of the proposed HE unit. Firstly, a traditional two step HE design methodology is utilised which works by initially evaluating a fully symmetric channel of the proposed HE corrugation (termed single channel). Then the results this model are incorporated into a simplified HE unit model. The second approach evaluates the HE unit performance based on a fully detailed CFD analysis that fully resolves flow and heat transfer inside the HE core. The third modelling approach involves splitting the inter-layer HE unit model into parts, which results in HE header models and allows simplification of the HE core into a single corrugation period width HE core model (termed superchannel). The results of these models are then compared to a conventional pin–fin HE unit model, formed by blocking the elliptical inter-layer conduits. It was found that in all the HE unit models the pressure drop is similar whilst the heat transfer was enhanced by between 7% and 13% in terms of the overall 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si68.svg"〉〈mrow〉〈mi mathvariant="normal"〉Δ〈/mi〉〈mi〉T〈/mi〉〈/mrow〉〈/math〉 by the inter-layer channels (increasing with the Reynolds number). All simulations were completed using a CFD package OpenFOAM.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉 〈p〉Author(s): Ehsan Sourtiji, Yoav Peles〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A concept to power micro synthetic jets using bubble growth and collapse is introduced and studied over a range of operating frequencies (0.1–2.5 Hz) and heating powers (3–4.5 W). The microfluidic device has no moving parts and uses the interfacial layer between the vapor and liquid phases which substitutes the requirement for a physical flexible membrane. A micro heater inside a chamber (3.5 mm in radius and a height of 220 µm) was connected to a main microchannel through a nozzle with a 300 µm opening. Periodically powering the micro-heater triggered bubble explosion and implosion in the chamber, which in turn generated the synthetic jet. Sequential images of bubble nucleation, growth and collapse were captured using high-speed camera photography and a microscope. A momentum coefficient was used to characterize the synthetic jet. It was found that its average value exceeds unity for a large range of operating frequencies suggesting that this synthetic jet can improve the performance of a range of micro-system performance, such as micro-mixing in microfluidic devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Chunlian Tian, Yu Chang, Zehui Zhang, Hong Wang, Shibo Xiao, Cancan Cui, Mingchun Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Research on the extraction technology, component analysis, and antioxidant, antibacterial, analgesic and anti-inflammatory activities of flavonoids fraction from 〈em〉Tribulus terrestris〈/em〉 L. leaves was carried out. The extraction process was optimized by response surface method, and the maximum yield 0.27% for flavonoids fraction was achieved with concentration of ethanol solution 25.87%, ratio of solvent to material 30:1 ml/g, and ultrasonic extraction time 27.93 min. Moreover, 14 compositions were identified separately from flavonoids fraction by HPLC-DAD-ESI-MS〈sup〉2〈/sup〉. In addition, flavonoids fraction exhibited a better antioxidant activity demonstrated by assays of ABTS, DPPH radical scavenging activity and ferric reducing antioxidant power activity. Furthermore, the antibacterial, analgesic and anti-inflammatory activities of flavonoids fraction were also proved to be stronger. Therefore, the present findings suggest that flavonoids fraction from 〈em〉Tribulus terrestris〈/em〉 L. leaves can be a very interesting candidate for the research and development of natural and healthy herbal medicine for the pharmaceutical and food industries.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Jamilah Borjac, Manal El Joumaa, Rawan Kawach, Lobna Youssef, Diane A. Blake〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Environmental pollution generated from uncontrolled dumping is a major problem in Lebanon due to the lack of proper waste management plans. Deir Kanoun Ras El Ain is the village that harbors the worst dumps in Lebanon. Wastewater leachates of this dump influx into an adjacent nearby canal used for irrigation and drinking purposes. The aim of this study is to assess the concentrations of heavy metals (Pb, Cd, As, and Hg) and the presence of organic compounds (phthalates, bisphenol A, and polycyclic aromatic hydrocarbons (PAHs)) in water samples collected from two different sites around the dump and two canal sites during winter and summer seasons. The concentrations of heavy metals were determined using atomic absorption spectrophotometry, while the identification of the extracted organic compounds was performed using High Performance Liquid Chromatography coupled to Mass Spectrometry (HPLC–MS). The carried analyses revealed that water samples collected from dump and canal were heavily polluted by Cd, As, Hg, phthalates, bisphenol A, and PAHs caused by pyrogenic and petrogenic sources. The concentrations of the found heavy metals were far above the maximum tolerable levels set by different guidelines. The findings suggest that the studied water sources are not safe for irrigation and drinking. The serious implications of dumping wastes on the health of inhabitants recall for an immediate employment of efficient waste management policies to resolve this problem.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Keisuke Okubo, Takashi Ito, Yasuyoshi Shiota, Yusuke Kawata, Tadashi Yamamoto, Shogo Takashiba〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Contamination of dental unit waterlines (DUWL) with heterotrophic bacteria can cause problems in immune compromised patients (aged, tumor and organ transplantation-patients). We focused on the use of low-concentrated ozonized water (OZW) as the biofilm formation restraint system for DUWL. Here, we examined the effects of low-concentrated OZW on the growth of bacteria and related biofilm formation and harmfulness to dental unit components (DUCs) 〈em〉in vitro〈/em〉.〈/p〉〈/div〉 〈div〉 〈h6〉Objectives〈/h6〉 〈p〉To evaluate the bactericidal effects of OZW on biofilms in DUWL and DUC 〈em〉in vitro〈/em〉.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉Low-concentrated OZW (0.4 mg/L) was generated using an OZS-PTDX generator. Heterotrophic bacterial biofilms in old DUWL tubes and 〈em〉Candia albicans〈/em〉 solution (control microbe) were treated with OZW for 1 h with gentle agitation before static culturing for 96 h in Reasoner's 2A liquid media. The control solutions were 0.1% cetylpyridinium chloride (CPC), chlorinated tap water (TW), and phosphate-buffered saline (PBS). Adenosine triphosphate (ATP) amounts of the microbes were measured and the biofilms of these microbes were observed using scanning electron microscopy (SEM). Moreover, surfaces of DUC soaked in OZW and TW were observed by SEM.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉The OZW reduced ATP levels in microbes to 50% compared to TW and PBS treatment, although CPC reduced it below detection limits. SEM observation revealed deformation of microbes cultured with OZW, whereas no changes were seen on DUC surfaces.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusions〈/h6〉 〈p〉Low-concentrated OZW is bactericidal against heterotrophic bacteria biofilms and it is not harmful to DUC, suggesting that it might be useful in preventing DUWL contamination.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): Christian Baresel, Vincent Schaller, Christian Jonasson, Christer Johansson, Romain Bordes, Vinay Chauhan, Abhilash Sugunan, Jens Sommertune, Sebastian Welling〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we have taken the concept of water treatment by functionalized magnetic particles one step forward by integrating the technology into a complete proof of concept, which included the preparation of surface modified beads, their use as highly selective absorbents for heavy metals ions (Zinc, Nickel), and their performance in terms of magnetic separation. The separation characteristics were studied both through experiments and by simulations. The data gathered from these experimental works enabled the elaboration of various scenarios for Life Cycle Analysis (LCA). The LCA showed that the environmental impact of the system is highly dependent on the recovery rate of the magnetic particles. The absolute impact on climate change varied significantly among the scenarios studied and the recovery rates. The results support the hypothesis that chelation specificity, magnetic separation and bead recovery should be optimized to specific targets and applications.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): C.S. Martinez, D.E. Igartúa, I. Czarnowski, D.A. Feas, S.delV. Alonso, M.J. Prieto〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The development and use of nanomaterials are increasing significantly. Among nanomaterials, carbon nanotubes are of particular interest due to its distinctive physicochemical properties. This material composed of sheets of graphite has very high thermal conductivity, metallic-type electrical conductivity, stiffness, toughness and unique ability to bond to itself in an extended network with extraordinary strength. Its application in the industry is continuously growing, which could lead to the accumulation in the environment and a consequent impact on both humans and ecosystems. Considering that environmental systems are dynamic, it is difficult to predict the risks associated with the release of nanomaterials to the environment. Bioindicators are useful tools as primary signals of environmental risk, and their responses reveal the organism and ecosystem health.〈/p〉 〈p〉In the present study, we evaluated the impact of multi-walled carbon nanotubes with different dimensions and agglomeration pattern on zebrafish embryo and larvae; mainly, studies were focused on physiological and behavioral responses. In embryos, measurements were hatching rate, morphology changes, and viability. In larvae, locomotor activity, heart rate, innate inflammatory response, general and tissue-specific morphology were measured. MWCNT-S (short, wide and mostly dispersed) caused depression of the locomotor activity of larvae, indicating an alteration of the central nervous system, and depression of neutrophil migration activity. MWCNT-L (long, thin and agglomerated) caused malformations during larval development, a decrease of neutrophil migration and alteration of cardiac rhythm. Results obtained for both carbon nanotubes were different, highlighting the importance of dimensions of the same nanomaterial, and also the kind of agglomeration and shape adopted, for the toxic effects on organisms.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 5, Issue 8〈/p〉 〈p〉Author(s): V.L. Lozano, C.E. Miranda, A.L. Vinocur, C. González, F. Unrein, M.J. Wolansky, H.N. Pizarro〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We evaluated the effect of AsiMax 50®, a commercial formulation of 2,4-D (2,4-dichlorophenoxyacetic acid), on the structure of both micro + nano phytoplankton (〉2 μm; species composition and abundance) and cytometric populations (photosynthetic picoplankton (PPP, 0.2–2 μm), which included prokaryotic phycocyanin-rich picocyanobacteria (PC-Pcy), phycoerythrin-rich picocyanobacteria (PE-Pcy) and eukaryotic phototrophs (PEuk); and bacterioplankton (HB), heterotrophic bacteria), using a microcosms-based approach and a single 7-day exposure. Assays were performed on two different microbial assemblages sampled from freshwater bodies of two contrasting turbidity status: clear (chlorophyll 〈em〉a〈/em〉 = 7.6 μgL〈sup〉-1〈/sup〉, turbidity = 1 NTU) and organic turbid systems (chlorophyll 〈em〉a〈/em〉 = 25.0 μgL〈sup〉-1〈/sup〉, turbidity = 9 NTU). For each system, the herbicide was applied to 500 mL-Erlenmeyer flasks, at seven concentration levels of the active ingredient (a.i.): 0 (control = no addition), 0.02, 0.2, 2, 20, 200 and 2,000 mg a.i.L〈sup〉−1〈/sup〉. The impact of AsiMax 50® seemed to be greater in the turbid system. In this system, total abundance of living (live) micro + nano phytoplankton showed a significant increase at lower concentrations and data were fitted to a humped-shaped curve. For both clear and organic turbid systems, micro + nano phytoplankton decreased in species richness and abundance at higher herbicide concentrations. These results suggest that 2,4-D may mimic hormonal function. Some species, such as 〈em〉Ochromonas〈/em〉 sp. and 〈em〉Chlamydomonas〈/em〉 sp., showed different responses to herbicide exposure between water systems. In the turbid system, the increase in abundance of the PPP fraction observed at 7-d exposure was probably due to either an increase in PE-Pcy (thus suggesting the existence of auxin pathways) or a reduction in competitive pressure by micro + nano plankton. Our results provide some evidence of the importance of using community-scale approaches in ecotoxicological studies to predict changes in freshwater ecosystems exposed to a 2,4-D-based formulation. However, caution must be taken when extrapolating these effects to real scenarios, as assays were based on a laboratory microcosm experiment.〈/p〉〈/div〉 〈/div〉