ALBERT

Description: Background: In computed tomography (CT) quality assurance, alignment of image quality phantoms is crucial for quantitative and reproducible evaluation and may be improved by alignment correction. Our goal was to develop an alignment correction algorithm to facilitate geological sampling of sediment cores taken from a cold-water coral mount. Methods: An alignment correction algorithm was developed and tested with a CT acquisition at 120 kVp and 150 mAs of an image quality phantom. Random translation (maximum 15 mm) and rotation (maximum 2.86°) were applied and ground-truth was compared to parameters determined by alignment correction. Furthermore, mean densities were evaluated in four regions of interest (ROIs) placed in the phantom low-contrast section, comparing values before and after correction to ground truth. This process was repeated 1000 times. After validation, alignment correction was applied to CT acquisitions (140 kVp, 570 mAs) of sediment core sections up to 1 m in length, and sagittal reconstructions were calculated for sampling planning. Results: In the phantom, average absolute differences between applied and detected parameters after alignment correction were 0.01 ± 0.06 mm (mean ± standard deviation) along the x-axis, 0.11 ± 0.08 mm along the y-axis, 0.15 ± 0.07° around the x-axis, and 0.02 ± 0.02° around the y-axis, respectively. For ROI analysis, differences in densities were 63.12 ± 30.57, 31.38 ± 32.10, 18.27 ± 35.57, and 9.59 ± 26.37 HU before alignment correction and 1.22 ± 1.40, 0.76 ± 0.9, 0.45 ± 0.86, and 0.36 ± 0.48 HU after alignment correction, respectively. For sediment core segments, average absolute detected parameters were 3.93 ± 2.89 mm, 7.21 ± 2.37 mm, 0.37 ± 0.33°, and 0.21 ± 0.22°, respectively. Conclusions: The alignment correction algorithm was successfully evaluated in the phantom and allowed a correct alignment of sediment core segments, thus aiding in sampling planning. Application to other tasks, like image quality analysis, seems possible.

Description: Hydro-alcoholic (2:8 v/v) extract of the pulp of Phoenix dactylifera fruit pulp obtained using Soxhlet extraction (70 °C, 6 h) was found to contain alkaloids, sterols, tannins, flavonoids, cardiac glycosides, proteins, and carbohydrates. An aqueous solution (20% v/v) of the extract led to the synthesis of silver nanoparticles (AgNPs) from 0.01 M AgNO 3 solution as confirmed by the surface plasmon resonance at 445 nm determined using UV–visible spectroscopy after 24 h. The synthesized AgNPs were found to be mostly spherical and complexed with phytochemicals from the extract. The size of AgNPs ranged from 12.2–140.2 nm with mean diameter of 47.0 nm as characterized by scanning electron microscopy (SEM). The elemental composition of the AgNPs complexed with the phytochemicals was found to be 80.49% silver (Ag), 15.21% carbon (C), and 4.30% oxygen (O) on a weight basis by energy-dispersive spectroscopy (EDS). Using the α,α-diphenyl-β-picrylhydrazyl (DPPH) assay, an anti-oxidant activity of 89.15% for 1 µg L −1 ultrasonically homogenized ethanolic solution of complexed AgNPs was obtained (equivalent to 0.20 mg mL −1 gallic acid solution), while methanolic solution of plant extract possessed an EC 50 value of 3.45% (v/v) (equivalent to 0.11 mg mL −1 gallic acid solution). The plant-nanosilver broth was also found to possess effective anti-microbial activity against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538, and Candida albicans ATCC 10231 as assessed by the disc diffusion assay. However, the plant extract showed negligible anti-microbial activity.

Description: The silica and copper oxide nanoparticles were embedded into the polyvinyl chloride film and obtained filled composites were tested as a catalyst in the reaction of the NO release from appropriate biomolecules. Obtained materials were characterized using scanning electron, atomic-force microscopies and thermomechanical analysis. It has been shown that the introduced particles are distributed uniformly in the polymeric matrix of hybrid composite and such film produces a significant amount of NO when reacts with S -nitrosothiols. At the same time, the unfilled polyvinyl chloride film had no statistically significant catalytic activity.

Description: Defects are inevitable most of the times either at the synthesis, handling or processing stage of graphene, causes significant deviation of properties. The present work discusses the influence of vacancy defects on the quantum capacitance as well as thermodynamic stability of graphene, and the nitrogen doping pattern needs to be followed to attain a trade-off between these two. Density Functional Theory (DFT) calculations have been performed to analyze various vacancy defects and different possible nitrogen doping patterns at the vacancy site of graphene, with an implication for supercapacitor electrodes. The results signify that vacancy defect improves the quantum capacitance of graphene at the cost of thermodynamic stability, while the nitrogen functionalization at the vacancy improves thermodynamic stability and quantum capacitance both. It has been observed that functionalizing all the dangling carbons at the defect site with nitrogen is the key to attain high thermodynamic stability as well as quantum capacitance. Furthermore, the results signify the suitability of these functionalized graphenes for anode electrode of high energy density asymmetric supercapacitors.

Description: In the present study, the interaction of optical radiation with a system of periodically arranged gold and silver nanowires of the square cross-sections on the dielectric substrate has been analyzed. The spectral character of the absorption, reflection and transmission at the interaction of the optical wave with nanogratings based on gold and silver is qualitatively and quantitatively different. It is explained by the fact that the imaginary part of the dielectric constant of gold is much larger than the imaginary part of the dielectric constant of silver in the spectral region of the plasmon resonance. Moreover, the electric fields which appear on the nanowires are considerably higher for silver than for gold.

Description: Organic–inorganic composite ion-exchangers based on anion exchange resins have been obtained. Particles of one-component and two-component modifier were embedded using the approach, which allows us to realize purposeful control of a size of the embedded particles. The approach is based on Ostwald–Freundlich equation, which was adapted to deposition in ion exchange matrix. The equation was obtained experimentally. Hydrated oxides of zirconium and iron were applied to modification, concentration of the reagents were varied. The embedded particles accelerate sorption, the rate of which is fitted by the model equation of chemical reactions of pseudo-second order. When sorption of arsenate ions from very diluted solution (50 µg dm −3 ) occurs, the composites show higher distribution coefficients comparing with the pristine resin.

Description: The isoquinoline quaternary alkaloid Berberine possesses a variety of pharmacological properties that suggests its promising application for an anticancer delivery system design utilizing its ability to intercalate DNA. In the current work, we have investigated the effects of Berberine on the human T cell leukemia cell line in vitro. Fluorescent microscopy of leukemic cells revealed Berberine nuclear localization. The results showed that Berberine inhibited leukemic cell growth in a time- and dose-dependent manner, that was associated with reactive oxygen species production intensification and caspase 3/7 activity increase with followed apoptosis induction. Berberine was used as a toxic and phototoxic agent for triple system synthesis along with DNA as a carrier and nanosilver as a plasmonic accelerator of Berberine electronic transitions and high energy emission absorbent centers. The proposed method allows to obtain the complex of DNA with Berberine molecules and silver nanoparticles. The optical properties of free components as well as their various combinations, including the final triple system DNA-Nanosilver-Berberine, were investigated. Obtained results support the possibility to use the triple system DNA-Nanosilver-Berberine as an alternative therapeutic agent for cancer treatment.

Description: The present article introduces a new software, Microstructure Evaluation Tool for Interface Statistics (METIS), that performs high-throughput microstructure statistical analysis from electron backscatter diffraction maps. Emphasis is placed on the detection of twin domains in hexagonal close-packed metals. The numerical framework on which METIS is built leverages graph theory, group structures, and associated numerical algorithms to automatically detect twins and unravel both their intrinsic characteristics features and those pertaining to their interactions. The proposed graphical interface allows for the detection and correction of unlikely twin/parent associations rendering the approach applicable to highly deformed microstructures. Twin statistics and microstructural data are classified and saved in a relational database that can be interrogated via either GUI or SQL requests to reveal a wide spectrum of features of the microstructure. Illustration of the approach is performed in the case of zirconium.

Description: Knowledge of material properties, microstructure, underlying material composition, and manufacturing process parameters that the material has undergone is of significant interest to materials scientists and engineers. A large amount of information of this nature is available in publications in the form of experimental measurements, simulation results, etc. However, getting to the right information of this kind that is relevant for a given problem on hand is a non-trivial task. First, an engineer has to go through a large collection of documents to select the right ones. Then, the engineer has to scan through these selected documents to extract relevant pieces of information. Our goal is to help automate some of these steps. Traditional search engines are not of much help here, as they are keyword centric and weak on relation processing. In this paper, we present a domain-specific search engine that processes relations to significantly improve search accuracy. The engine preprocesses material publication repositories to extract entities such as material compositions, material properties, manufacturing processes, process parameters, and their values and builds an index using these entities and values. The engine then uses this index to process user queries to retrieve relevant publication fragments. It provides a domain-specific query language with relational and logical operators to compose complex queries. We have conducted an experiment on a small library of publications on steel on which searches such as “get the list of publications which have carbon composition between 0.2 and 0.3 and on which tempering is carried out for about 30 to 40 min” are performed. We compare the results of our search engine with the results of a keyword-based search engine.

Description: The paper asserts that each new urban and land planning approach, (ranging from the environment assessment procedures and land suitability analysis introduced in the past, to the newer methods of resilience an...

Description: Research was conducted to identify a series of neuropsychological tests to assess the ability to drive. Driving performance of young and old UK drivers was modeled through multiple linear regression and univariate logistic regression tools. The UFOV3 test (i.e. the third subtest of the UFOV test) had comparatively high discriminating ability in separating poor-drivers from not-poor-drivers, with 92.86% of the drivers correctly classified; the UFOV3 test resulted in a Sensitivity of 62.5%. Age and a composite cognitive measure were also found to be sound discriminators of poor-drivers and not-poor-drivers with 91.07% and 89.28% of the drivers correctly classified respectively; both age and the composite cognitive measure resulted in a Sensitivity of 50%. It was found that the commonly recommended Clock Drawing Test and the Trail Making-B test were insignificant predictors of driving ability. Results suggest that for a score greater than 220 on the UFOV3 test, the driver may be further evaluated by a driving specialist to ascertain questionable driving behavior. Also, drivers above the age of 77 were more susceptible to exhibiting unusual driving behavior; if such drivers have UFOV3 scores greater than 220 it would be more appropriate to evaluate driving behavior through a driving specialist.

Description: Purpose This study analyzes the relationship that land use has with weekend travel in comparison to weekday travel. Unlike previous studies, it uses the same sample for two models that are specified to test the relationship separately for weekday and weekend travel. Methods Structural equation modeling is employed to test the land use–travel relationship. A comparison is made using two mode-specific travel measures: trip frequency and travel time. Results On weekday travel, land use in Seoul tends to reduce automobile trips and to add transit and nonmotorized trips. This does not lead to a reduction in the total frequency of weekday trips. Instead, an overall reduction occurs in the frequency of weekend trips because the addition of transit and nonmotorized trips is less than the reduction of automobile trips. Conclusions The application of structural equation modeling to a Seoul household travel survey confirms the opposing role of land use in travel mode choices on weekdays versus weekends.

Description: Introduction This paper presents an analytical model to contrast the carbon emissions from a number of goods delivery methods. This includes individuals travelling to the store by car, and delivery trucks delivering to homes. While the impact of growing home delivery services has been studied with combinatorial approaches, those approaches do not allow for systematic conclusions regarding when the service provides net benefit. The use of the analytical approach presented here, allows for more systematic relationships to be established between problem parameters, and therefore broader conclusions regarding when delivery services may provide a CO 2 benefit over personal travel. Methods Analytical mathematical models are developed to approximate total vehicle miles traveled (VMT) and carbon emissions for a personal vehicle travel scenario, a local depot vehicle travel scenario, and a regional warehouse travel scenario. A graphical heuristic is developed to compare the carbon emissions of a personal vehicle travel scenario and local depot delivery scenario. Results The analytical approach developed and presented in the paper demonstrates that two key variables drive whether a delivery service or personal travel will provide a lower CO 2 solution. These are the emissions ratio, and customer density. The emissions ratio represents the relative emissions impact of the delivery vehicle when compared to the personal vehicle. The results show that with a small number of customers, and low emissions ratio, personal travel is preferred. In contrast, with a high number of customers and low emissions ratio, delivery service is preferred. Conclusions While other research into the impact of delivery services on CO 2 emissions has generally used a combinatorial approach, this paper considers the problem using an analytical model. A detailed simulation can provide locational specificity, but provides less insight into the fundamental drivers of system behavior. The analytical approach exposes the problem’s basic relationships that are independent of local geography and infrastructure. The result is a simple method for identifying context when personal travel, or delivery service, is more CO2 efficient.

Description: Purpose The current study examined the relations between objective and subjective measures of driving patterns, focusing on traffic violations. In addition, the study explored the potential use of rewards in order to modify driving behaviors and examined the relationship between attitudinal and demographic variables and the frequency of speeding. Method We acquired subjective and objective data on driving behaviors in a sample of 114 young student drivers in Israel’s Southern region. We used a survey to acquire data on the participants’ history of violations, self-reported driving behavior, and subjective attitudes towards risks and fines. We then examined the participants’ objective driving behaviors using Get Location, a specifically designed smartphone application. Results We found a substantive gap between subjective and objective data regarding traffic violations, but they were also significantly correlated. The demographic variables, including gender, failed to distinguish between frequent and non-frequent speeders, while attitudinal variables succeeded. Frequent speeders required a significantly higher potential reward, as well as a higher fine to motivate behavioral changes. Conclusion Self-reported data can serve as a reasonable proxy for measuring the tendency to adopt particular driving patterns, including the tendency to engage in violations. In addition, the use of rewards can complement or possibly replace the reliance on negative sanctions in order to modify behavior.

Description: Introduction Electric bikes (e-bikes) may help in transport decarbonisation in European cities. To fully assess the market potential of e-bikes, further research is needed to understand users' preferences and the range of factors that can contribute to people to shift from car use to low carbon vehicles such as e-bikes. This paper is built on the Be4Schools R&D project implemented in the smart city of Águeda in Portugal. It comprised the former study in the country that examined the willingness of students (aged 15-21 years) to use e-bikes for daily trips to school and that gathered their preferences towards specific ICT related attributes. Methods The methodology comprised a mobility survey and a stated-choice experiment (SC). The SC experiment gathered 2232 observations for modelling which were able to provide the relevant attribute informa'on trade-off between car travel, route and e-bike features (with or without specific ICT equipment). An extensive econometric analysis using was performed to assess the nature and extent of students' heterogeneity of preferences which also considered gender issues. The study aimed to contribute to the regional economic cluster on powered two-wheels' industry & innovation. Results The absence of cycling infrastructures (segregated from main road) and the absence of cycle lanes in the road infrastructure were ranked as the first, second and third most important barriers, by 25.4% and 24.8% of the students, respectively. The importance of a dedicated cycling route to school (segregated from main traffic) revealed to be critical as the odds of choosing an e-bike was found to be 6.5 times higher in comparison with the “no cycling infrastructure” option, ceteris paribus. This finding is aligned with the fact that cyclists would need to be exposed to high levels of motorized traffic in main roads and to increased perceived risks. The market potential of e-bikes is likely to be higher if ICT features can be added to e-bikes as the odds of choosing an e-bike when it comes with the preferred ICT devices is 1.7 times higher than the opposed situation (e-bike without additional ICT devices). Conclusions Research results are interesting for mobility policies and industry as the possible integration of ICT equipment in e-bikes may speed up the market uptake of this technology in smart cities. On the other hand, cycling infrastructures seem to be critical elements for increasing the demand for both conventional and e-bikes in the smart city of Águeda.

Description: Evolution education, in both schools and informal education, often focuses on natural selection and the fit of organisms through natural selection to their environment and way of life. Examples of evidence tha...

Description: The arrival of the Anthropocene presents many challenges—both theoretical and practical. Scholars in different disciplines, practitioners, the public and others, are all considering the meaning of the Anthropo...

Description: The copula–entropy theory combines the entropy theory and the copula theory. The entropy theory has been extensively applied to derive the most probable univariate distribution subject to specified constraints...

Description: After publication of the article (Tian et al. 2018), it has been brought to our attention that the date included in the caption of Figure 3 is incorrect. The caption states that the photographs were taken on “...

Description: Over decades, sunspots and their fine structures have been studied in detail at the photospheric level with different ground-based telescopes, as the surface of the Sun primarily emits light in the visible wav...

Description: The greediness of multimedia applications in terms of their bandwidth demands calls for new and efficient network traffic control mechanisms, especially in wireless networks where the bandwidth is limited. In ...

Description: Geologic mapping, a magnetotelluric survey, well data, and earlier reports are integrated to guide further development of the Fang geothermal system. The Fang Hot Springs originally flowed ~ 20 l s−1 of 90–99 °C ...

Description: The Taupo Volcanic Zone (TVZ) hosts 23 geothermal fields, seven of which are currently utilised for power generation. Ngatamariki geothermal field (NGF) is one of the latest geothermal power generation develop...

Description: Heat storage capabilities of deep sedimentary geothermal reservoirs are evaluated through numerical model simulations. We combine storage with heat extraction in a doublet well system when storage phases are r...

Description: A 1912-m exploration corehole was drilled along the axis of the eastern Snake River Plain, Idaho. Two temperature logs run on the corehole display an obvious inflection point at about 960 m. Such behavior is i...

Description: For over 100 years, designers of aerospace components have used simple requirement-based material and process specifications. The associated standards, product control documents, and testing data provided a certifiable material definition, so as to minimize risk and simplify procurement of materials during the design, manufacture, and operation of engineered systems, such as aerospace platforms. These material definition tools have been assembled to ensure components meet design definitions and design intent. They must ensure the material used meets “equivalency” to that used in the design process. Although remarkably effective, such traditional materials definitions are increasingly becoming the limiting challenge for materials, design, and manufacturing engineers supporting modern, model-based engineering. Demands for cost-effective, higher performance aerospace systems are driving new approaches for multi-disciplinary design optimization methods that are not easily supportable via traditional representations of materials information. Furthermore, property design values having the definitions based on statistical distributions from testing results can leave substantial margin or material capability underutilized, depending on component complexity and the application. Those historical statistical approaches based on macroscopic testing inhibit innovative approaches for enhancing materials definitions for greater performance in design. This can include location-specific properties, hybrid materials, and additively manufactured components. Development and adoption of digital and model-based means of representing engineering materials, within a design environment, is essential to span the widening gap between materials engineering and design. We believe that the traditional approach to defining materials by chemistry ranges, manufacturing process ranges, and static mechanical property minima will migrate to model-based material definitions (MBMDs), due to the many benefits that result from this new capability. This paper reviews aspects of the challenges and opportunities of model-based engineering and model-based definitions.

Description: Sclerosing cholangitis is the liver disease of uncertain etiology, extremely unfavorable prognosis and lack of effective medication therapy. Therefore, the effect of water-soluble biocompatible C 60 fullerenes (C 60 FAS) on the liver functional state on rat acute-cholangitis model was aimed to be discovered. Acute cholangitis was simulated by single α-naphthyl isothiocyanate (ANIT, 100 mg/kg) per os administration; C 60 FAS (0.5 mg/kg) was administered either per os or intraperitoneally in 24 and 48 h after ANIT ingestion, and in 72 h the animals were sacrificed. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), the total and direct bilirubin, creatinine and urea in the blood serum were determined, and the liver morphological state was assessed. In animals experienced ANIT-induced acute cholangitis, the total and direct bilirubin, creatinine, ALT, AST, ALP and LDH 1.5–4-fold increase were observed, indicating cytolysis of hepatocytes, cholestasis, and renal dysfunction. The features of periductal fibrosis, biliary epithelium atrophy, and portal–portal linking septa formation were detected, confirming the sclerosing cholangitis development. C 60 FAS promoted to the normalization of direct and total bilirubin levels, the ALT activity and diminution of fibrotic features. In addition, C 60 FAS intraperitoneal administration also normalized the ALP activity, indicating the attenuation of disease symptoms. However, the AST activity and creatinine level remained unchanged, and the LDH activity even increased, manifesting the partial persistence of cholestasis and renal dysfunction. Thus, the therapeutic application of C 60 FAS promotes a partial protection of liver against cholangitis.

Description: The mixed SiO 2 –TiO 2 oxide obtained by the pyrogenic method with the silica:titanium percentage ratio equal to 80:20 (ST20) was used as a potential adsorbent for the removal of hazardous azo dye C.I. Acid Yellow 219 (AY219) from aqueous solutions. Based on the values of determination coefficients ( r 2 ), it can be stated that the Freundlich ( r 2  = 0.929) model fitted the experimental data better than the Langmuir ( r 2  = 0.920) and Tempkin ( r 2  = 0.848) ones. In the system containing 20 mg/L AY219, the amount of dye adsorbed ( q t ) by ST20 was equal to 9.7 mg/g and the time necessary to reach equilibrium was 120 min. The sorption of AY219 on ST20 may be described by the pseudo-second-order model ( r 2  = 0.999) as the adsorption capacity was calculated as 9.69 mg/g. The amount of AY219 adsorbed decreased with the increasing concentration of additives such as anionic and non-ionic (Triton X-100) surfactants. In the presence of cationic surfactant, the reverse dependence was observed. Anionic dye additions influence the structure of electrical double layer formed on the surface of mixed oxide particles. The presence of negative charges in adsorbed AY219 molecules results in increase of the solid surface charge density with simultaneous decrease of the zeta potential of ST20 particles. The addition of surfactants with different ionic character causes formation of complexes whose presence at the mixed oxide–liquid interface influences considerably both the solid surface charge density and the zeta potential of ST20 particles dispersed in aqueous solution.

Description: Nanostructured organic thin film with polarized luminescence is obtained by means of the vapor deposition of fluorescent liquid crystalline dipolar molecules in the presence of polarized laser irradiation outside the absorption band. It was shown that irradiation of molecules by non-resonant polarized laser beam during deposition strongly decreases the formation of aggregated molecules that is confirmed by atomic force microscopy, fluorescent microscopy and luminescent spectroscopy.

Description: The third-order nonlinear optical properties of gold nanoparticles embedded in the DNA-based composites were investigated by means of the third harmonic generation. With this purpose, the thin films comprising DNA-based complexes and Au nanoparticles were spin-deposited on glass substrate and their optical and nonlinear optical features were studied using the Maker-fringe technique at a laser fundamental wavelength of 1064 nm. The values of the third-order susceptibility χ (3) (− 3 ω ; ω , ω , ω) of the composite films based on DNA complex doped with 5 wt% of N -ethyl- N -(2-hydroxyethyl)-4-(4-nitrophenylazo)aniline were found to be significantly higher than those for pure composite films. Meanwhile, the presence of Au nanoparticles noticeable decreases the third-order nonlinear response of DNA-based composite mainly due to the enhanced absorption and scattering of laser and generated beam, respectively.

Description: An algorithm for non-intrusively coupling a commercial finite element software with a research code implementing a hierarchical enrichment of finite element spaces is presented. Examples of hierarchical method...

Description: This study investigates the factors affecting the inter-organizational relationships and governance of firms in agri-food supply chains and assesses the influence that the current conditions of vertical coordi...

Description: Gender differences in fish processors’ willingness to pay for a group-owned fish solar tent dryer (FSTD) are being assessed by using the double hurdle model. Willingness to pay (WTP) responses from 382 randoml...

Description: This paper considers the problem of the simultaneous finite-time event-triggered control and fault detection for a class of continuous-time singular Markovian jump mixed delay systems (SMJDSs) under asynchrono...

Description: In this paper, using the theory of q-fractional calculus, we deal with the q-Mittag-Leffler stability of q-fractional differential systems, and based on it, we analyze the direct Lyapunov method of q-fractional d...

Description: This article analyzes the impact of participation in off-farm activities on technical efficiency of maize production in eastern Ethiopia. We combined propensity score matching with a stochastic production fron...

Description: This work demonstrates a competitive reduction method of synthesis of nanomaterials. In this method along cetyltrimethylammonium bromide (CTAB), the reduction of Ag + and Fe 3+ ions is achieved by ascorbic acid-to-bimetallic Ag@Fe yellow-colored nanomaterials. The shape of UV–visible spectra and wavelengths absorbed of Ag@Fe can be tuned from ca. 290–600 nm by controlling [CTAB] and [Ag + ]. The apparent first-order rate constants were calculated within the approximation of 6.1 × 10 −3  s −1 . The as-prepared Ag@Fe NPs have been found to be very important catalyst in terms of depredate methyl orange in vicinity of sodium borohydride (NaBH 4 ), which exhibits excellent efficiency and re-usability in the prototypical reaction. The cmc of cationic surfactant CTAB has been determined by conductivity method under different experimental conditions. In the presence of CTAB, Ag + and Fe 3+ ions reduce to Ag@Fe core/shell nanoparticles, comprehend a change in wavelength and intensity of SRP band. The apparent first-order rate constant, activation energy, and turnover frequency for the methyl orange reduction catalyzed by Ag@Fe NPs were found to be 1.6 × 10 −3  s −1 , 58.2 kJ mol −1 , and 1.1 × 10 −3 s −1 , respectively.

Description: A simple method for the synthesis of magnetite nanoparticles using the leaf extract of Calliandra haematocephala has been developed. UV–Vis spectrum showed a characteristic strong absorption band. SEM image revealed the bead-like spherical nanoparticles. EDS showed the prominent peaks for elemental iron and oxygen. PXRD patterns confirmed the crystalline nature and the average crystallite size of 7.45 nm. In addition, the lattice parameter value was calculated to be 8.413 Å, close to Fe 3 O 4 nanoparticles. BET analysis disclosed the total specific surface area of the nanoparticles as 63.89 m 2 /g and the mesoporous structure of the nanoparticles with a pore radius of 34.18 Å. FTIR studies showed the specific bands at 599.82 and 472.53 cm −1 , typical for Fe 3 O 4 nanoparticles. The photocatalytic efficacy of the nanoparticles was demonstrated against the degradation of malachite green dye under sunlight irradiation and the photocatalytic degradation constant was calculated as 0.0621 min −1 .

Description: Titanium-dioxide photocatalyst was impregnated onto the activated carbon using originally developed low-temperature sol–gel method to form a TiO 2 :AC composite material. 15% (mass.) solution Ti 2 (SO 4 ) 3 in sulphuric acid was used as a precursor for photocatalyst synthesis. The highly effective composite material was obtained through a combination of properties of titanium dioxide and activated carbon. Synthesized composites TiO 2 with activated carbon demonstrate highly developed surface characteristics and exhibit significantly higher activity in comparison with samples of pure TiO 2 synthesized the same way, existing analogues of pure TiO 2 synthesized from TiCl 3 and even industrial photocatalyst. This was testified by the degradation of 1% aqueous glucose solution using TiO 2 :AC, samples of pure TiO 2 and commercial TiO 2 AEROXIDE ® TiO 2 P25 produced by EVONIK Industries.

Description: The present manuscript describes a simple, facile and effective solvothermal route to synthesize Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs), reduced graphene oxide nanosheets (rGO NSs) and Fe 3 O 4 /reduced graphene oxide nanohybrid composite (Fe 3 O 4 /rGO nanohybrid composite) and subsequently examines their comparative biocompatibilities. The as-obtained Fe 3 O 4 NPs, rGO NSs and Fe 3 O 4 /rGO nanohybrid composite have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The XRD studies and scanning electron microscope confirmed the proper phase formation and the surface morphology of the as-synthesized products, respectively. The Raman spectra of Fe 3 O 4 NPs show the strongest peak at 673 cm −1 which can be assigned to A 1g peak of bare Fe 3 O 4 NPs and it complements the XRD studies. Furthermore, the increment in the I D / I G ratio in the Fe 3 O 4 /rGO nanohybrid composite suggests the creation of defects in graphene sheets due to strain caused by Fe 3 O 4 NPs. The biocompatibility of these samples has been tested using Lung cancer cell line H1299 through MTT assay. The MTT assay reveals that the nanohybrid composite endows more biocompatible and effectiveness than rGO NSs and Fe 3 O 4 NPs individually, as anti-proliferative agent for cancer treatment.

Description: In this paper, experiments were conducted to study the tribological behavior of synthetic oil containing nanodiamond (ND) with molybdenum disulphide (MoS 2 ) and tungsten disulphide (WS 2 ) nanoparticles. The experiments were performed in boundary lubrication regime for steel/steel contacts. A ball on disc configuration was used to obtain the frictional characteristics of the lubricating oils at a constant velocity of 0.58 m/s. Scanning electron microscopy and energy dispersive spectroscopy were carried out to evaluate the wear behavior of the worn out disc samples. The results obtained from the investigation exhibited an improvement in both wear and friction coefficient. On addition of 0.2% ND in the oil containing MoS 2 and WS 2 nanoparticles, the coefficient of friction (COF) and wear volume decreased around two times in comparison to the PAO oil. The enhancement in overall lubrication behavior is mainly due to the synergism between the MoS 2 /ND and WS 2 /ND nanoparticles.

Description: This study selected the Dunhuang city with the unique landscape pattern, its oasis surround by desert, for studying the vegetation change. Based on two period GaoFen-1 images, combined with field survey data, the dimidiate pixel model and fractional vegetation coverage estimation model were applied to detect the changes of local vegetation coverage from July 2013 to July 2015. Analysis showed that during the study years, the Grain for Green project had a remarkable effect on the changes. The vegetation types of intermediate high and very low grades increased by 0.66 and 6.78 km 2 respectively. The low vegetation coverage decreased by 23.87 km 2 . The vegetation coverage types of intermediate grade increased by 88.97 km 2 because of the planted forest, which accounted for 10.84% of the study area. The vegetation coverage types of high grade reduced by 72.47 km 2 . This change effectively prevents the spread of desert and lays a good foundation for the ecological construction of Dunhuang city.

Description: A novel radar-based system for longwall coal mine machine localisation is described. The system, based on a radar-ranging sensor and designed to localise mining equipment with respect to the mine tunnel gate road infrastructure, is developed and trialled in an underground coal mine. The challenges of reliable sensing in the mine environment are considered, and the use of a radar sensor for localisation is justified. The difficulties of achieving reliable positioning using only the radar sensor are examined. Several probabilistic data processing techniques are explored in order to estimate two key localisation parameters from a single radar signal, namely along-track position and across-track position, with respect to the gate road structures. For the case of across-track position, a conventional Kalman filter approach is sufficient to achieve a reliable estimate. However for along-track position estimation, specific infrastructure elements on the gate road rib-wall must be identified by a tracking algorithm. Due to complexities associated with this data processing problem, a novel visual analytics approach was explored in a 3D interactive display to facilitate identification of significant features for use in a classifier algorithm. Based on the classifier output, identified elements are used as location waypoints to provide a robust and accurate mining equipment localisation estimate.

Description: When there are installations of air velocity sensors in the mining industry for real-time airflow monitoring, a problem exists with how the monitored air velocity at a fixed location corresponds to the average air velocity, which is used to determine the volume flow rate of air in an entry with the cross-sectional area. Correction factors have been practically employed to convert a measured centerline air velocity to the average air velocity. However, studies on the recommended correction factors of the sensor-measured air velocity to the average air velocity at cross sections are still lacking. A comprehensive airflow measurement was made at the Safety Research Coal Mine, Bruceton, PA, using three measuring methods including single-point reading, moving traverse, and fixed-point traverse. The air velocity distribution at each measuring station was analyzed using an air velocity contour map generated with Surfer ® . The correction factors at each measuring station for both the centerline and the sensor location were calculated and are discussed.

Description: Circulating fluidized bed (CFB) gasification has several advantages for the utilization of low rank coals. However, the carbon content of fly ash is usually very high, which greatly influences the gasification efficiency. The purpose of this research is to investigate the gasification reactivity of a high-sodium Zhundong (ZD) coal fly ash obtained from a pilot-scale 2.5 t/d CFB gasification system. The experiments were carried out in a thermogravimetric analyzer with steam as gasification agent, and fast pyrolyzed ZD char was also investigated as a reference sample. The results show that increasing temperature accelerates the gasification rate both for fly ash and ZD char. Fly ash has higher gasification rate at the initial gasification stage. On the contrary, ZD char has higher reaction rate even at higher carbon conversion stage. Via distributed activation energy model, the average activation energy of ZD char and fly ash is calculated to be 94.4 and 91.2 kJ/mol, respectively. The integrated model study reveals that the reaction order of ZD char is about 0.74, whereas the reaction order of fly ash decreases from 1 to 0.59 when temperature increases from 900 to 1050 °C. The gasification reactivity of ZD coal fly ash is quite different with literature research on those fly ashes with rarely little catalytic elements in coal ashes. The interesting results are related with the unique properties of ZD coal fly ash and the transformation of sodium during gasification process.

Description: Three-dimensional simulations of diesel particulate matter (DPM) distribution inside a single straight entry for the Load-Haul-Dump loader (LHD)-truck loading and truck hauling operations were conducted by using ANSYS FLUENT computational fluid dynamics software. The loading operation was performed for a fixed period of 3 min. The dynamic mesh technique in FLUENT was used to study the impact of truck motion on DPM distribution. The resultant DPM distributions are presented for the cases when the truck were driving upstream and downstream of the loading face. Interesting phenomena were revealed in the study including the piston effect, layering of DPM in the roof region, and backflow of diesel exhaust against ventilation. The results from the simulation can be used to determine if the areas inside the face area and straight entry exceed the current U.S. regulatory requirement for DPM concentration (〉160 µg/m 3 ). This research can guide the selection of DPM reduction strategies and improve the working practices for the underground miners.

Description: Solvent extraction phenol from coal tar were carried out with novel composite YH-3 as extraction agent, and the high flux centrifugal extractor was used as extraction device. Under the premise of high phenol extraction rate, composite YH-3 extraction agent reduces π–π interaction between phenolic compounds and aromatic hydrocarbons, thus decreasing the entrainment of neutral oil. The optimization of operation conditions, such as the diameter of heavy phase weir HWD, the flow ratio, the total flow rate and the rotation speed, are necessary. For single stage extraction experiment, the mass transfer efficiency was up to 84% while the rate of extraction agent loss was lower than 0.28% with the operation conditions of 29 mm of the heavy phase weir diameter (HWD), 1:1–1.4:1 of the flow ratio range, 160–200 mL/min of the total flow rate and the rotation speed varied from 2200 to 2600 r/min. For three stage counter-current test, the mass transfer efficiency reached up to 92.6% with the optimum operation condition of 29 mm of the HWD, 1:1 of the flow ratio, 200 mL/min of the total flow rate and 2400 r/min of the rotation speed. The results indicated that phenol could be extracted effectively from coal tar in the process of multistage continuous count current centrifugal extraction.

Description: Optical microscopy, and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry (SEM-EDX), have been used to study the minerals and the concentrations of 12 trace elements in the No.14 coal from the Huolinhe mine, Inner Mongolia China. The distribution, affinity and removability of the trace elements were studied by float-sink experiments and petrological methods. A high mineral content, dominated by clay minerals, was found in the No.14 coal from the Huolinhe mine. The concentrations of As, Sb and Hg are relatively high compared to the average values for Chinese coals. As, Cr, Hg, Li, Mn, Pb are mainly associated with the minerals while Cd, Co, Ni, Sb, and Se are evenly distributed between the minerals and the organic matter. Be and Ba are mainly distributed in the minerals with a minor proportion in the organic matter. Most elements have a low organic affinity, although Sb, Se, Co, Cd, Ni are closely integrated with the organic matter. High theoretical removabilities are indicated for most trace elements. So it may be possible to lower the concentrations of trace elements during coal preparation.

Description: Sandwich panels comprising prefabricated ultra-high performance concrete (UHPC) composites can be used as eco-friendly and multi-functional structural elements. To improve the structural and thermal performance of composite sandwich panels, combinations of UHPC and expanded polystyrene (EPS) beads were investigated. High-performance expanded polystyrene concrete (HPEPC) was tested with various EPS bulk ratios to determine the suitability of the mechanical properties for use as a high-strength lightweight aggregate concrete. As a core material in composite sandwich panels, the mechanical properties of HPEPC were compared with those of EPS mortar. The compressive strength of HPEPC is approximately eight times greater than that of EPS mortar, and the thermal conductivity of approximately a quarter that of EPS mortar. The structural behavior of composite sandwich panels was empirically analyzed using different combinations of cores, face sheets, and adhesive materials. In the flatwise and edgewise compression tests, sandwich panels with HPEPC cores had high peak strengths, irrespective of the type of face sheets, as opposed to the specimens with EPS mortar cores. In the four-point bending tests, the sandwich panels with HPEPC cores, or reinforced UHPC face sheets combined with adhesive mortar, exhibited higher peak strengths than the other specimens, and failed in a stable manner, without delamination.

Description: The durability performance of stainless steel makes it an interesting alternative for the structural strengthening of reinforced concrete. Like external steel plates or fibre reinforced polymers, stainless steel can be applied using externally bonded reinforcement (EBR) or the near surface mounted (NSM) bonding techniques. In the present work, a set of single-lap shear tests were carried out using the EBR and NSM bonding techniques. The evaluation of the performance of the bonding interfaces was done with the help of the digital image correlation (DIC) technique. The tests showed that the measurements gathered with DIC should be used with caution, since there is noise in the distribution of the slips and only the slips greater than one-tenth of a millimetre were fairly well predicted. For this reason, the slips had to be smoothed out to make it easier to determine the strains in the stainless steel and the bond stress transfer between materials, which helps to determine the bond–slip relationship of the interface. Moreover, the DIC technique allowed to identify all the states developed within the interface through the load–slip responses which were also closely predicted with other monitoring devices. Considering the NSM and the EBR samples with the same bonded lengths, it can be stated that the NSM system has the best performance due to their higher strength, being observed the rupture of the stainless steel in the samples with bond lengths of 200 and 300 mm. Associated with this higher strength, the NSM specimens had an effective bond length of 168 mm which is 71.5% of that obtained for the EBR specimens (235 mm). A trapezoidal and a power functions are the proposed shapes to describe the interfacial bond–slip relationships of the NSM and EBR systems, respectively, where the maximum bond stress in the former system is 1.8 times the maximum bond stress of the latter one.

Description: This paper presents the results of the tests and analysis on the coefficient of thermal expansion for the steel strand under combined low temperatures and prestressing forces. A test program was firstly carried out to study the thermal expansion behaviour of the seven-wire strand under combined different low temperatures ranging from 20 to − 165 °C and different prestressing levels ranging from 0 to 0.75 f t / f tk . The test results exhibited the thermal expansion behaviours of the steel strand under low temperatures in terms of thermal strain versus temperature curves, transit linear thermal expansion coefficient, and average thermal expansion coefficient. The influences of the low temperature and prestressing levels on the thermal expansion behaviours of the steel strand were separately discussed and analysed. Based on the test data, mathematical models were developed to predict the thermal expansion coefficients including transit and average of the steel strand. The developed regression models fully considered the influences of the low temperature and prestressing stresses acted on the strand. Finally, design equations were proposed to predict the transit and average thermal expansion coefficient of the steel strand under combined low temperature and prestressing forces.

Description: Rehabilitation and repair of flexible pavements produce huge amounts of reclaimed asphalt pavement (RAP) material. Using RAP in the formulation of portland cement concrete (PCC) is a technique that is part of a sustainable development approach since it reduces on the consumption of new aggregates and reuses a material that is considered as waste. This paper describes the semi-adiabatic calorimetry test performed on a concrete mix incorporating RAP material as aggregate. Results showed that the cement hydration process is not affected by the presence of asphalt coated on the surface of RAP material. Classical tests (compressive strength, flexural and indirect-tensile strengths, elastic modulus, and free-shrinkage) were also performed on PCC mixes incorporating different percentages of RAP. It was found that as the percentage of RAP increases, the PCC mechanical properties decrease. This is mainly attributed to the presence of voids in the transition zone between the asphalt-coated aggregates and the hydrated cement paste as confirmed by scanning-electron microscope images. Unrestrained shrinkage testing showed statistically insignificant change in shrinkage strain with RAP content. The strength and shrinkage results lead to conclude that as much as 40% of RAP could be incorporated into the formulation of PCC and achieve properties that are acceptable for the construction of rigid pavements.

Description: Strut and Tie (S&T) models are used for the design of what are known as “discontinuity regions” in reinforced concrete (RC) structures. Building codes such as ACI-318 and Eurocode 2 do not give information on the nodes that only connect ties in S&T models (called TTT or tension-only nodes). However, their use is not explicitly prohibited in the design of RC structures. In this work, a comparison between solutions which have been designed both considering and not considering TTT nodes is evaluated. Four RC beams (designed with and without TTT nodes) were subjected to three-point bending. Experimental results show that TTT nodes are a good design solution for special cases of discontinuity regions in RC structures. However, the experimental campaign has proven that this type of node is more vulnerable to errors during construction than solutions designed without TTT nodes.

Description: Recycled aggregates (RAs) production techniques are essential for the material circulation society because RAs from demolished concrete waste can sustainably be reused as a concrete material. However, RAs can bring about several performance decreases when they are used for recycled aggregate concrete (RAC) because of the low qualities (i.e., high water-absorption rate and low density) caused by the attached hydrated cement paste on the RA surface. Therefore, both the production of high-quality RAs and the surface modification of RAs are significantly important for the extension of RAC utilization. This paper focuses on the surface modification of RFA to reduce the water absorption rate and increase density. Hydrofluorosilicic acid (H 2 SiF 6 ), which is one of the by-products in phosphoric acid manufacture, is used herein for the surface modification of the RFA. The physical properties and mechanical performance of mortar using RFA were evaluated after RFA modification. Consequently, the proposed method is effective in reducing water absorption rate and increasing density of RFA. The density of RFAs was slightly increased by 0.5–2.6% after modification. On the other hand, the water absorption rate decreased by 4–18% after modification. The compressive strengths of mortar at 28 days ages showed 18.1 MPa with modified RFA and 16.2 MPa with RFA.

Description: Chloride ions diffuse through the concrete cover and interact with the cement hydration products. As a result, some chloride ions become chemically and/or physically bound. Free chloride ions are the primary cause of steel corrosion in reinforced concrete structures. In this study, ultrasound was used to detect the presence and binding of chloride ions in cement pastes that contained supplementary cementing materials. Four cement pastes with w/c ratio of 0.55 were prepared and cast into cylindrical specimens that were moist cured for 254 days before being oven dried at 105 °C. The dried specimens were vacuum-saturated with NaCl solutions at various concentrations. Through-transmission ultrasonic measurements were performed as a function of time using 500 kHz longitudinal wave transducers. The results indicated exponential relationships between energy/amplitude weighted average frequency and the amount of chloride chemically bound by the cement pastes.

Description: Complications of pregnancy and childbirth are a leading cause of maternal morbidities and mortalities in developing countries. World Health Organization (WHO) estimates that over 500,000 women and girls die ea...

Description: Extraction of valuable data from extensive datasets is a standout amongst the most vital exploration issues. Association rule mining is one of the highly used methods for this purpose. Finding possible associa...

Description: Massive graphs are ubiquitous and at the heart of many real-world problems and applications ranging from the World Wide Web to social networks. As a result, techniques for compressing graphs have become increa...

Description: Next-Generation Sequencing technologies are generating a huge amount of genetic data that need to be mapped and analyzed. Single machine sequence alignment tools are becoming incapable or inefficient in keepin...

Description: In the last decade, significant advances have been made in sensing and communication technologies. Such progress led to a considerable growth in the development and use of intelligent transportation systems. C...

Description: This paper estimates the impact of the 2010 Haiti earthquake on the household decision about children’s time allocation. Using original data and objective geological measures, we exploit the fact that the eart...

Description: Using a unique administrative dataset, this study investigates the employment and earnings trajectories of temporary foreign workers (TFWs) during the years surrounding their acquisition of permanent residence...

Description: This paper aims to analyze the increasing issue of overcongestion affecting the immigration hosting facilities of many Italian municipalities, as well as the heterogeneity in immigration regulatory behavior em...

Description: The Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) is one of the recently negotiated multilateral free trade agreements which aims to establish a free trade agreement between 11 ...

Description: Fractal theory and regression analysis were employed for the first time to investigate the effect of pore size and pore distribution on high-temperature mechanical properties of porous alumina ceramics (PAC). In the present work, PAC with the comparable porosity, different pore sizes and pore distributions were prepared using carbon black as the pore-forming agent. Particular emphasis in this study was placed on the establishment of correlation between the thermal shock resistance and pore properties. The relationship between fractal dimension ( D f ) and thermal shock resistance parameter ( R st ) in specimens presented the negative power function, indicating that low D f could benefit the improvement of thermal shock resistance in specimens. The results showed that the increase of pore size and pore sphericity leads to a reduced D f , the enhanced hot modulus of rupture (HMOR) and R st . The decrease of proportion of micro-pores below 2 μm, the increase of mean pore size and pore sphericity could result in the decrease of D f , and then improve R st and HMOR of specimens. Based on the correlation between R st and pore characteristics, PAC with improved thermal shock stRstRresistance could be achieved when their pore structure meets the above features.

Description: The CeVO 4 /graphitic C 3 N 4 composites have exhibited much enhanced photocatalytic property for degrading methylene blue (MB) pollutant under visible light irradiation compared with single-phase g-C 3 N 4 or CeVO 4 . The composite S5 obtained from an optimized mass ratio (5%) of CeVO 4 to dicyanamide (DCDA) exhibits the highest photocatalytic activity. Here, ternary Ag/CeVO 4 /g-C 3 N 4 composites denoted as X %Ag/S5 were prepared by an ultrasonic precipitation method to improve the photocatalytic property of S5. The TEM images show that CeVO 4 and Ag nanoparticles are well distributed on the layered g-C 3 N 4 , which agree well with the XRD results. The UV spectra show that the 7%Ag/S5 sample has the widest absorption range and the enhanced absorption intensity under visible light irradiation. The corresponding band gap of 7%Ag/S5 (2.5 eV) is much lower than that of S5 (2.65 eV). The corresponding k value of 7%Ag/S5 is much higher than those of g-C 3 N 4 and CeVO 4 . The degradation experiments for MB solution suggest that the 7%Ag/S5 sample has the optimal photocatalytic performance, which can degrade MB solution completely within 120 min. The enhanced photocatalytic property of the composites is ascribed to not only the effect of heterojunction structure, but also the surface plasma resonance effect of Ag nanoparticles.

Description: Low-cost porous ceramic microspheres from waste gangue were prepared by simple spray drying and subsequent calcination. Effects of calcination temperature on phase and microstructure evolution, specific surface area, pore structure, and dye adsorption mechanism of the microspheres were investigated systematically. Results showed that the microspheres were spherical, with some mesopores both on the surface and inside the spheres. The phase kept kaolinite after calcined at 800 and 900°C and transformed into mullite at 1000°C. The microspheres calcined at 800°C showed larger adsorption capacity and removal efficiency than those calcined at higher temperatures. Methylene blue (MB) and basic fuchsin (BF) removal efficiency reached 100% and 99.9% with the microsphere dosage of 20 g/L, respectively, which was comparable to that of other low-cost waste adsorbents used to remove dyes in the literature. Adsorption kinetics data followed the pseudo-second-order kinetic model, and the isotherm data fit the Langmuir isotherm model. The adsorption process was attributed to multiple adsorption mechanisms including physical adsorption, hydrogen bonding, and electrostatic interactions between dyes and gangue microspheres. The low-cost porous microspheres with excellent cyclic regeneration properties are promising absorbent for dyes in wastewater filtration and adsorption treatment.

Description: The accurate evaluation of the elastic modulus of ceramic coatings at high temperature (HT) is of high significance for industrial application, yet it is not easy to get the practical modulus at HT due to the difficulty of the deformation measurement and coating separation from the composite samples. This work presented a simple approach in which relative method was used twice to solve this problem indirectly. Given a single-face or double-face coated beam sample, the relative method was firstly used to determine the real mid-span deflection of the three-point bending piece at HT, and secondly to derive the analytical relation among the HT moduli of the coating, the coated and uncoated samples. Thus the HT modulus of the coatings on beam samples is determined uniquely via the measured HT moduli of the samples with and without coatings. For a ring sample (from tube with outer-side, inner-side, and double-side coating), the relative method was used firstly to determine the real compression deformation of a split ring sample at HT, secondly to derive the relationship among the slope of load-deformation curve of the coated ring, the HT modulus of the coating and substrate. Thus, the HT modulus of ceramic coatings can be evaluated by the substrate modulus and the load-deformation data of coated rings. Mathematic expressions of those calculations were derived for the beam and ring samples. CVD-SiC coatings on graphite substrate were selected as the testing samples, of which the measured modulus ranging from room temperature to 2100 °C demonstrated the validity and convenience of the relative method.

Description: Synthesis and sintering of ZrB 2 –SiC based composites have been carried out in a single-step pressureless reaction sintering (PLRS) of ZrO 2 , B 4 C, and Si. Y 2 O 3 and Al 2 O 3 were used as sintering additives. The effect of ratios of ZrO 2 /B 4 C, ZrO 2 /Si, and sintering additives (Y 2 O 3 and Al 2 O 3 ), was studied by sintering at different temperatures between 1500 and 1680 °C in argon atmosphere. ZrB 2 , SiC, and YAG phases were identified in the sintered compacts. Density as high as 4.2 g/cm 3 , micro hardness of 12.7 GPa, and flexural strength of 117.6 MPa were obtained for PLRS composites. Filler material was also prepared by PLRS for tungsten inert gas (TIG) welding of the ZrB 2 –SiC based composites. The shear strength of the weld was 63.5 MPa. The PLRS ZrB 2 –SiC composites exhibited: (i) resistance to oxidation and thermal shock upon exposure to plasma flame at 2700 °C for 600 s, (ii) thermal protection for Cf–SiC composites upon exposure to oxy-propane flame at 2300 °C for 600 s.

Description: Hollow silica–alumina composite spheres were prepared by a polystyrene (PS) template method using various amounts of PS suspension. Homogeneous hollow spheres prepared using 40 g were found to be with a diameter of about 300 nm in scanning electron microscopy, and transmission electron microscopy demonstrated their hollow sphere morphology. From the nitrogen adsorption isotherm results, the homogeneous hollow spheres prepared using 40 g of the PS suspension were found to be an ordered pore structure. The activities of the hollow spheres prepared using various amounts of the PS suspension for hydrolytic dehydrogenation of ammonia borane were compared. The results showed that 10, 7, and 6 mL of hydrogen were evolved from the aqueous ammonia borane solution in about 40 min in the presence of the hollow spheres prepared using 40, 80, and 120 g of PS suspension, respectively. The homogeneous hollow spheres with an ordered pore structure showed the highest activity among all the hollow spheres. The amount of acid sites and the coordination number of aluminum active species were characterized using neutralization titration and solid-state 27 Al magic angle spinning nuclear magnetic resonance spectroscopy. The homogeneous hollow spheres with an ordered pore structure had high amount of acid sites and 4-coordinated aluminum species. The relative proportion of 4-coordinated aluminum species was related to the dispersion of aluminum species. These results indicate that the homogeneous hollow spheres with an ordered pore structure showed the high activity because of high amount of acid sites induced by the highly dispersed aluminum species.

Description: Here we consider our four-point flexure and compression creep results obtained under Ar protection at 1800 °C to predict the tensile creep behavior of a ZrB 2 –20 vol% SiC ultra-high temperature ceramic. Assuming power law creep, and based on four-point bend data, we estimated the uniaxial creep parameters using an analytical method present in the literature. Both predicted and experimental compressive stress exponents were found to be in excellent agreement, 1.85 and 1.76 respectively, while observation of the microstructure suggested a combination of diffusion and grain boundary sliding creep mechanisms in compression. Along with the microstructural evidence associated with the tensile regions of the flexure specimens, the predicted tensile stress exponent of 2.61 exceeds the measured flexural value of 2.2. We assert an increasing role of cavitation to the creep strain in pure tension. This cavitation component adds to the dominant grain boundary sliding mechanism as described below and elsewhere for flexural creep.

Description: A tri-layer coating of mullite/Y 2 Si 2 O 7 /(70wt%Y 2 Si 2 O 7 +30wt%Y 2 SiO 5 ) was prepared on carbon fiber reinforced silicon carbide (C/SiC) composite substrate through dip-coating route for the sake of improving oxidation resistance of C/SiC composites. An Al 2 O 3 –SiO 2 sol with high solid content was selected as raw material for mullite, and a slurry of Y 2 O 3 powder filled silicone resin was used to synthesize yttrium silicate. The microstructure, phase composition, and oxidation resistance of the coating were investigated. The as-fabricated coating shows high density and favorable bonding to C/SiC substrate. After oxidation at 1400 and 1500 °C for 30 min under static air, the flexural strengths of coated C/SiC composite were both increased by ~30%. The desirable thermal stability and the further densification are responsible for excellent oxidation resistance. With the additional help of compatible thermal expansion coefficients among substrate and sub-layers in coating, the coated composite retained 111.2% of original flexural strength after 12 times of thermal shock in air from 1400 °C to room temperature. The carbothermal reaction at 1600 °C between free carbon in C/SiC substrate and rich SiO 2 in mullite resulted in severe frothing and desquamation of coating and obvious degradation in oxidation resistance.

Description: Internationalization is a complex process, in which firms face various challenges that may lead to opportunities or threads. One of these challenges is export compliance. The objective of this paper is to dise...

Description: Compared to traditional point load forecasting, probabilistic load forecasting (PLF) has great significance in advanced system scheduling and planning with higher reliability. Medium term probabilistic load forecasting with a resolution to an hour has turned out to be practical especially in medium term energy trading and can enhance the performance of forecasting compared to those only utilizing daily information. Two main uncertainties exist when PLF is implemented: the first is the temperature fluctuation at the same time of each year; the second is the load variation which means that even if observed indicators are fixed since other observed external indicators can be responsible for the variation. Therefore, we propose a hybrid model considering both temperature uncertainty and load variation to generate medium term probabilistic forecasting with hourly resolution. An innovative quantile regression neural network with parameter embedding is established to capture the load variation, and a temperature scenario based technique is utilized to generate temperature forecasting in a probabilistic manner. It turns out that the proposed method overrides commonly used benchmark models in the case study.

Description: The integration of natural gas in electricity network requires a more reliable operating plan for increasing uncertainties in the whole system. In this paper, a three-stage robust optimization model is proposed for resilient operation of energy system which integrates electricity and natural gas transmission networks with the objective of minimizing load curtailments caused by attacks. Non-convex constrains are linearized in order to formulate the dual problem of optimal energy flow. Then, the proposed three-stage problem can be reformulated into a two-stage mixed integer linear program (MILP) and solved by Benders decomposition algorithm. Numerical studies on IEEE 30-bus power system with 7-node natural gas network and IEEE 118-bus power system with 14-node natural gas network validate the feasibility of the proposed model for improving resilience of integrated energy system. Energy storage facilities are also considered for the resiliency analysis.

Description: This paper proposes an economic optimization method with two time scales for a hybrid energy system based on the virtual storage characteristic of a thermostatically controlled load (TCL). The optimization process includes two time scales in order to ensure accuracy and efficiency. Based on the forecast load and energy supply of the system, the first time scale is day-ahead economic operating optimization, carried out to determine the minimum operating cost for the whole day, and to find the period of greatest cost to which the second time scale optimization is applied. Using the virtual storage characteristic, the second time scale is short term detailed optimization carried out for these particular hours. By dispatching thermal load in this period and adjusting energy supply accordingly, we can find the optimal economic performance, and customer requests are taken into account to ensure satisfaction. A case study in Tianjin illustrates the effectiveness of this method and proves that a TCL can make a great contribution to improving the economic performance of a hybrid energy system.

Description: In this paper, a battery energy storage system (BESS) based control method is proposed to improve the damping ratio of a target oscillation mode to a desired level by charging or discharging the installed BESS using local measurements. The expected damping improvement by BESS is derived analytically for both a single-machine-infinite-bus system and a multi-machine system. This BESS-based approach is tested on a four-generator, two-area power system. Effects of the power converter limit, response time delay, power system stabilizers and battery state-of-charge on the control performance are also investigated. Simulation results validate the effectiveness of the proposed approach.

Description: This paper gives an overview of previous studies on photovoltaic (PV) devices, grid-connected PV inverters, control systems, maximum power point tracking (MPPT) control strategies, switching devices and transformer-less inverters. The literature is classified based on types of PV systems, DC/DC boost converters and DC/AC inverters, and types of controllers that control the circuit to ensure maximum power tracking and stabilization of load and input voltage. This is followed by the theoretical background of PV devices, an overview of MPPT controllers and common mode leakage current, and a detailed investigation of different inverter topologies regarding the ground leakage current. Furthermore, design principles of power converters, such as DC/DC boost converters, and single-phase inverters are discussed. The paper also discusses limitations and benefits in addition to the basic operating principles of several topologies. Finally, the proposed system is derived and its simulation results are discussed to offer the next generation of grid connected PV systems.

Description: Distributed generation including wind turbine (WT) and photovoltaic panel increased very fast in recent years around the world, challenging the conventional way of probabilistic load flow (PLF) calculation. Reliable and efficient PLF method is required to take into account such changing. This paper studies the maximum entropy probabilistic density function reconstruction method based on cumulant arithmetic of linearized load flow formulation, and then develops a maximum entropy based PLF (ME-PLF) calculation algorithm for power system integrated with wind power generation (WPG). Comparing to traditional Gram–Charlier expansion based PLF (GC-PLF) calculation method, the proposed ME-PLF calculation algorithm can obtain more reliable and accurate probabilistic density functions (PDFs) of bus voltages and branch flows in various WT parameter scenarios. It can solve the limitation of GC-PLF calculation method that mistakenly gaining negative values in tail regions of PDFs. Linear dependence between active and reactive power injections of WPG can also be effectively considered by the modified cumulant calculation framework. Accuracy and efficiency of the proposed approach are validated with some test systems. Uncertainties yielded by the wind speed variations, WT locations, power factor fluctuations are considered.

Description: Short-circuit fault current suppression is a very important issue in modern large-interconnected power networks. Conventional short-circuit current limiters, such as superconducting fault current limiters, have to increase additional equipment investments. Fast power electronics controlled flexible AC transmission system (FACTS) devices have opened a new way for suppressing the fault current levels, while maintaining their normal functionalities for steady-state and transient power system operation and control. Thyristor controlled phase shifting transformer (TCPST) is a beneficial FACTS device in modern power systems, which is capable of regulating regional power flow. The mathematical model for TCPST under different operation modes is firstly investigated in this study. Intuitively, the phase shifting angle control can adjust the equivalent impedance of TCPST, but the effect has been demonstrated to be weak. Therefore, a novel transformer excitation impedance switching (EIS) control method, is proposed for fault current suppressing, according to the impedance characteristics of TCPST. Simulation results on IEEE 14-bus system have shown considerable current limiting characteristic of the EIS control under various fault types. Also, analysis of the timing requirement during fault interruption, overvoltage phenomenon, and ancillary mechanical support issues during EIS control is discussed, so as to implement the proposed EIS control properly for fast fault current suppression.

Description: This paper presents a novel commutation failure (CF) assessment method considering the influences of voltage magnitude drop, phase shift, and spatial-temporal discreteness of AC system faults. The commutating voltage-time area is employed to analyze the spatial-temporal discreteness of AC system faults causing CF in high-voltage direct current systems, and the influences of fault position and fault time on CF are revealed. Based on this, a novel CF criterion is proposed, further considering the influence of voltage phase shift and the spatial-temporal discreteness. Then this research develops a new CF assessment method, which does not rely on electromagnetic transient simulations. A real case from the China Southern Power Grid is used to verify the practicability of the proposed method by comparing with simulation results obtained using PSCAD/EMTDC.

Description: This paper compares three methods of load forecasting for the optimum management of community battery storages. These are distributed within the low voltage (LV) distribution network for voltage management, energy arbitrage or peak load reduction. The methods compared include: a neural network (NN) based prediction scheme that utilizes the load history and the current metrological conditions; a wavelet neural network (WNN) model which aims to separate the low and high frequency components of the consumer load and an artificial neural network and fuzzy inference system (ANFIS) approach. The batteries have limited capacity and have a significant operational cost. The load forecasts are used within a receding horizon optimization system that determines the state of charge (SOC) profile for a battery that minimizes a cost function based on energy supply and battery wear costs. Within the optimization system, the SOC daily profile is represented by a compact vector of Fourier series coefficients. The study is based upon data recorded within the Perth Solar City high penetration photovoltaic (PV) field trials. The trial studied 77 consumers with 29 rooftop solar systems that were connected in one LV network. Data were available from consumer smart meters and a data logger connected to the LV network supply transformer.

Description: Work time measurements are the starting point for any calculation of unit costs of machine exploitation; therefore, the accuracy of evaluating these costs determines the economic effectiveness of technological...

Description: Eucalyptus species can be alternative plantation species to Pinus radiata D.Don (radiata pine) for New Zealand. One promising high value use for eucalypts is laminated veneer lumber (LVL) due to their fast growth...

Description: A large quantity of radionuclides was released by the Fukushima Daiichi Nuclear Power Plant accident in March 2011, and those deposited on ground and vegetation could return to the atmosphere through resuspens...

Description: Within the current organization of design activities it is difficult to fully realize the potential of BIM (Building Information Modelling). In BIM processes, it is necessary to identify and exchange the speci...

Description: This paper explores the potential for using remotely sensed data from a combination of commercial and open-sources, to improve the functionality, accuracy of energy-use calculations and visualisation of carbon...

Description: Nowadays, nanomaterials that are smaller than 100 nm in size are very attractive owing to their enhanced physicochemical properties. Although they have been used widely for industrial applications, their toxicity still remains a problem. This article is a new record of the synthesis of titanium dioxide nanoparticles (TiO 2 NPs) by a Mentha aquatica leaf extract and determination of its toxicity to rat marrow mesenchymal stem cells. In this study, we aimed to determine the genotoxic and cytotoxic effects of biologically synthetized TiO 2 NPs. The characteristic peak of the nanomaterial was observed at 354 nm. The mean size of the nanomaterial was measured to be 69 nm from SEM images. According to zeta analysis, the surface charge of the nanomaterial was − 37.6 mV. The crystalline structure of the nanomaterial was determined using XRD analysis. It was concluded that the obtained nanomaterial was TiO 2 The results of the FT-IR analysis showed that the functional groups that were found in the plant extract could play an important role in the formation and stabilization of TiO 2 NPs. The effective size of the TiO 2 NPs was found to be 304 nm using DLS analysis. The TGA analysis results showed that the total mass loss was 4% at 900 °C. According to DNA cleavage analysis results, TiO 2 NPs cause damage to the plasmid pBR322 DNA in a concentration-dependant matter. It has been noted that TiO 2 NPs lead to decreased cell viability during increased time and concentration of applications on rat marrow mesenchymal stem cells. It has also been determined that bulk TiO 2 causes a greater reduction in the stem cell viability compared to the biosynthesized NPs. The obtained results could be useful for further application and toxicity studies.

Description: In recent years, the synthesis of gold nanostructures of controllable shapes and dimensions has become a subject of intensive and interesting studies. Especially, anisotropic gold nanostructures such as nanoplates, nanoribbons, nanoprisms and nanorods have attracted much attention due to their striking optical properties and promising applications in electronics, photonics, sensing and biomedicine. Keeping this in mind, in the present report, an unprecedented, facile and one pot synthesis of isotropic (spherical) and anisotropic (triangular, pentagonal, hexagonal, rod shaped) gold nanomaterials via pH controlled shape modulation using hydroxyl moeity containing α-amino acids (Serine, Threonine, Tyrosine) as both reducing and capping agents is reported. The synthesized nanostructures have been further characterized by UV–Vis spectroscopy and transmission electron microscopy. It was deduced from these studies that pH played a key role in the anisotropic growth of gold nanostructures. These gold nanoparticles can be further used for applications in biosensing, plasmonics, and electrocatalysis and others involving surface enhanced raman scattering. This study is therefore, important from the point of view of using amino acids for the synthesis of gold nanoparticles of different shapes and sizes leading towards the development of inventive biosensors and biocompatible nanoconstructs.

Description: In this work, the kinetic of positron–electron annihilation in the MgO–Al 2 O 3 spinel-type ceramics sintered at different temperatures (1100, 1200 and 1400 °C) has been calculated and analyzed in a frequency domain. The spectra of real (in-phase) and imaginary (quadrature) components of positron–electron annihilation kinetic have been obtained numerically from usual temporal characteristics using integral Fourier transform. The numerical calculations were carried out using cubic spline interpolation of the pulse characteristics of MgO–Al 2 O 3 ceramics in time domain with following analytical calculations of integrals. The obtained spectra as real so imaginary part of MgO–Al 2 O 3 ceramics in frequency domain almost good obey a Debye law denying correlation between elementary positron annihilation processes. Complex diagrams of frequency domain responses of as-prepared samples have a shape of semicircles with close characteristic frequencies. Some deviation on low-frequency side of the semicircles is observed confirming an availability of longer time kinetic processes. Sintering temperature dependencies of the relaxation times and characteristic frequencies of positron–electron annihilation processes have been obtained. It is shown that position of large maxima on the frequency dependencies of imaginary part corresponds to fast average relaxation lifetime representing the most intensive interaction process of positrons with small cavity traps in solids.

Description: We study the influence of dynamic capping of Fe 3 O 4 nanoparticles with phosphate and oleic acid, on their structure, magnetic properties and thermal stability of magnetic nanoparticles. It is observed that the phosphate coating on iron oxide lowers the dipole–dipole interaction significantly, as compared to oleic acid capping. The Mössbauer results show that the spin canting order of oxidized shell and the mean hyperfine field values follow the order Fe0 (uncoated) 〉 FeOA (oleic acid capped) 〉 FP1 (phosphate capped). The uncoated Fe 3 O 4 nanoparticle is non-stoichiometric in nature due to oxidation, whereas FP1 and FeOA are of the correct stoichiometry. Mössbauer and photoacoustic spectroscopic studies on air-annealed phosphate-coated magnetite nanoparticles confirm that the magnetic iron oxide phase is preserved up to 833 K and a complete conversion of Fe 3 O 4 into the non-magnetic hematite phase occurs at 1173 K. The iron oxide air annealed at 833 K is found to have a shell of orthorhombic α-Fe 2 O 3 over the magnetite core. However, in oleic acid-coated nanoparticles, the magnetic to non-magnetic phase transformation commences at 623 K and the conversion was complete at 823 K. The photoacoustic spectra of the air-annealed phosphate-coated Fe 3 O 4 particles showed a flipping of the absorption intensity between 500−700 nm and 800−1000 nm, due to the conversion of Fe 3 O 4 to γ-Fe 2 O 3 at 923 and γ-Fe 2 O 3 to α-Fe 2 O 3 at 1173 K, respectively. The γ-Fe 2 O 3 showed an intense absorption peak above 750 nm, whereas the α-Fe 2 O 3 showed a peak broadening in the wavelength range of 600–700 nm, in addition to the strong peaks at a wavelength above 750 nm. This study suggests that the photoacoustic spectroscopy can distinguish clearly the three polymorphs of iron oxide i.e., Fe 3 O 4 , γ-Fe 2 O 3 and α-Fe 2 O 3 . Our results confirm the ability of phosphate-capped iron oxide particles to retard the oxidation of Fe 2+ contents during the crystal growth process.

Description: This paper presents experimental results on the preparation and investigation of the carbon nanotubes–copper composite material. Carbon nanotubes (CNTs) were synthesized on silicon substrates by the chemical vapor deposition (CVD) method and then filled with copper by evaporation from a melting pot in a vacuum. Copper evenly covered both the surface of the entangled tubes and the free substrate surface between the tubes. To improve the adhesion of tubes and matrix material, a carbon substructure was grown on the surface of tubes by adding working gas plasma to the CNT synthesis area. It is proposed to use a copper coating as a diffusion barrier upon subsequent filling of the reinforcing CNT frame by a carbide-forming materials matrix with predetermined physico-mechanical and tribological properties.

Description: The partial decoupling of electronic and optical properties of organic solar cells allows for realizing solar cells with increased short circuit current and energy conversion efficiency. The proposed device consists of an organic solar cell conformally prepared on the surface of an array of single and double textured pyramids. The device geometry allows for increasing the optical thickness of the organic solar cell, while the electrical thickness is equal to the nominal thickness of the solar cell. By increasing the optical thickness of the solar cell, the short circuit current is distinctly increased. The quantum efficiency and short circuit current are determined using finite-difference time-domain simulations of the 3D solar cell structure. The influence of different solar cell designs on the quantum efficiency and short circuit current is discussed and optimal device dimensions are proposed.

Description: Within the framework of the methods of the electron density functional and the ab initio pseudopotential, we have obtained the valence electron density spatial distribution, the densities of electron states, the widths of band gaps, the charges on combined regions, and the Coulomb potentials for graphene-based flexible 2D layered junctions, using author program complex. It is determined that the bending of the 2D layered junctions on the angle α leads to changes in the electronic properties of these junctions. In the graphene/graphane junction, there is clear charge redistribution with different signs in the regions of junctions. The presence in the heterojunctions of charge regions with different signs leads to the formation of potential barriers. The greatest potential jump is in the graphene/fluorographene junction. The greatest value of the band gap width is in the graphene/graphane junction.

Description: Coal combustion and gasification are the processes to utilize coal for production of electricity and many other applications. Global energy demand is increasing day by day. Coal is an abundant source of energy but not a reliable source as it results into high CO 2 emissions. Energy industries are expected to decrease the CO 2 emission to prevent global warming. Coal gasification is a process that reduces the CO 2 emission and emerges as a clean coal technology. Coal gasification process is regulated by several operating parameters. A Number of investigations have been carried out in this direction. A critical review of the work done by several researchers in the field of coal gasification has been compiled in this paper. The effect of several operating parameters such as coal rank, temperature, pressure, porosity, reaction time and catalyst on gasification has been presented here.

Description: In this paper, we consider a stochastic SIR epidemic model with regime switching. The Markov semigroup theory will be employed to obtain the existence of a unique stable stationary distribution. We prove that,...

Description: Migration policies can have a strong impact on the selection of immigrants, who in turn can affect the host country’s innovation development. This paper examines the effects of the liberalization of migration ...

Description: This study presents the photoluminescence characteristics of the PZT 53/47 system doped at A and/or B sites, with Nb (PZTN), La (PLZT), and Nb–La (PLZTN) in the concentration range from 0.2 to 1.0 molar fraction. The intensity of the emission bands of the system PZTN is two orders higher than the intensity of the emission bands of the systems PLZT and PLZTN, and these emission bands are located at 1.73 eV (718 nm), 2.56 eV (485 nm), and 2.93 eV (424 nm). The origin of the luminescence in these systems is associated with lead and oxygen vacancies produced during the sintering process. The results from X-ray diffraction (XRD) show a mixture of rhombohedral and tetragonal phases. The system PZTN shows a higher tetragonal phase concentration, while PLZT and PLZTN systems show a higher rhombohedral phase concentration. The cell volume shows an increase with dopant concentration only in the case of the PLZTN system. The band gap energy shows a small variation in the PZTN and PLZTN cases around 3.0 eV, a close value to the band gap energy of the pure PZT 53/47 sample. The system PLZT shows an increasing behavior until 4.41 eV for the higher dopant concentration.