ALBERT

Beschreibung: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Energy Conversion and Management, Volume 196〈/p〉 〈p〉Author(s): Zhendong Zhang, Hui Qin, Yongqi Liu, Liqiang Yao, Xiang Yu, Jiantao Lu, Zhiqiang Jiang, Zhongkai Feng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a renewable and clean energy, wind energy plays an important role in easing the increasingly serious energy crisis. However, due to the strong volatility and randomness of wind speed, large-scale integration of wind energy is limited. Therefore, obtaining reliable high-quality wind speed prediction is of great importance for the planning and application of wind energy. The purpose of this study is to develop a hybrid model for short-term wind speed forecasting and quantifying its uncertainty. In this study, Minimal Gated Memory Network is proposed to reduce the training time without significantly decreasing the prediction accuracy. Furthermore, a new hybrid method combining Quantile Regression and Minimal Gated Memory Network is proposed to predict conditional quantile of wind speed. Afterwards, Kernel Density Estimation method is used to estimate wind speed probabilistic density function according to these conditional quantiles of wind speed. In order to make the model show better performance, Maximal Information Coefficient is used to select the feature variables while Genetic Algorithm is used to obtain optimal feature combinations. Finally, the performance of the proposed model is verified by seven state-of-the-art models through four cases in Inner Mongolia, China from five aspects: point prediction accuracy, interval prediction suitability, probability prediction comprehensive performance, forecast reliability and training time. The experimental results show that the proposed model is able to obtain point prediction results with high accuracy, suitable prediction interval and probability distribution function with strong reliability in a relatively short time on the prediction problems of wind speed.〈/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-S0196890419306958-ga1.jpg" width="159" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Renewable Energy, Volume 146〈/p〉 〈p〉Author(s): K.R. Arun, M. Srinivas, C.A. Saleel, S. Jayaraj〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, an outdoor experimental analysis is conducted to determine the impact on the useful heat gain when discrete cylindrical energy storage units are directly integrated into the solar collector. The collector has a double-pass airflow channel pathway, and the storage is intended to serve only for a short-term. The location of storage inside the collector is always a major concern. This study seeks to determine whether the thermodynamic performance of the system is effective by the location of cylindrical energy storage (paraffin wax) capsules on the upper or the lower airflow channel pathway. The obtained results suggest that due to asymmetric channel depth, the thermodynamic performance of the collector was not greatly influenced by the placement of capsules, unlike with symmetric channel depths. The amount of useful heat gain when storage was placed in the upper (Case A) and lower (Case B) airflow pathways was 0.35 kW and 0.4 kW. For Case A and Case B, the average collector thermal efficiency was 62.9% and 73.7%, and the exergy efficiency was 44.3% and 47.5%. The energy payback time for the collector based on energy calculations is nine months, and that on exergy analysis is 34 months and 20 days.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Renewable Energy, Volume 146〈/p〉 〈p〉Author(s): Yan Wu, Shuai Zhang, Ruiqi Wang, Yufei Wang, Xiao Feng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wind farm designing is a crucial stage to realize the application of wind energy. This work studies the problem of wind farm layout optimization (WFLO). A new method based on power production, wind distribution, wake loss is proposed to optimize the layout of wind farm. Genetic algorithm (GA) is utilized to optimize the locations of wind turbine in the wind farm. GeoSteiner algorithm is used to optimize the layouts of cable which has important influence on power transmission. The objective function is annual economic benefit (AEB) including annual production benefit (APB) and the costs of energy, cable and land. In the case study, the wind farm size is 3850 m × 3850 m. The number of wind turbines (WTs) of the cases changes from 2 to 58. The capacity achieves 87 MW when the number of WTs is 58. The result shows that the case considering all factors mentioned above has the highest AEB with 1.87 × 10〈sup〉9〈/sup〉 ¥ per year. There is a 27.01% increase compared with the original case with APB as objective function. Specifically, the investment of cable is 3.68 × 10〈sup〉6〈/sup〉 ¥ comparing with 4.06 × 10〈sup〉6〈/sup〉 ¥ of the case only considering APB.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Renewable Energy, Volume 146〈/p〉 〈p〉Author(s): José Núñez, Miguel F. Moctezuma-Sánchez, Elizabeth M. Fisher, Víctor M. Berrueta, Omar R. Masera, Alberto Beltrán〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The fluid flow, heat transfer, and gas-phase chemical reactions for a natural-draft plancha-type biomass cookstove are studied at steady state with a commercial CFD code, ANSYS Fluent™. Different firepowers (in the range of real operating conditions), modeled as different flow rates of wood volatiles entering the 3D computational domain, were investigated. Firepower was found to have minimal effect on the air flow rate through the cookstove and the efficiency, but to strongly affect stove temperatures and heating rates. The main results were duplicated by a simple analytical model with one tunable parameter, and with simplified combustion, heat transfer, fluid properties, and pressure losses. The analytical model highlights the importance of the air mass flow rate through the cookstove, which is affected by design choices. The largest diferences between the CFD model and the analytical model occurred at the lower firepowers, when temperatures were so low that combustion was incomplete.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Renewable and Sustainable Energy Reviews, Volume 113〈/p〉 〈p〉Author(s): S.K. Kim, K.H. Cho, J.Y. Kim, G. Byeon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents long-term field test results of lithium-polymer and advanced lead-acid battery systems for consumer load management. The battery systems aimed to minimize electricity bills of an industrial consumer by shifting its load to lower priced time-zones and regulating its peak. Annual and daily peak reduction effects and operating revenues are examined under a time-of-use tariff and battery promotional incentive. Capacity degradations of the batteries are calculated to estimate the actual lifetime. Based on actually earned revenue during the field test and predicted service life for the each type of the batteries, total expected revenue per unit installation capacity is estimated and compared with investment cost per capacity to perform the economics of the tested battery systems for consumer load. This analysis found that the profitability cannot be assured under the considered time-of-use pricing alone but can be expected when adequate incentive is provided. It is also revealed that the batteries in real use conditions lose their capacity considerably quicker than suggested by manufacturers. Therefore, it is recommended to consider actual fading pattern of the battery for accurate economic evaluation at the design stage and to reflect the battery degrading cost into the charge-discharge scheduling model to optimize operating revenue.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Renewable Energy, Volume 146〈/p〉 〈p〉Author(s): Fujiao Tang, Hossein Nowamooz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Generally, a Horizontal Ground Heat Exchanger (HGHE) is installed in shallow depths, which can influence the land surface temperature during its operation period, especially when a high heat demand is required. Consequently, the existing methods of using time-varying land surface temperatures are not sufficient for the HGHE simulations. In this paper, a numerical framework considering the atmosphere-soil-HGHE interaction was proposed and validated. The outlet temperatures of a slinky-type HGHE installed in a multi-layered soil field were then investigated under the heating scenario by considering the local meteorological and geological conditions. The results showed that the operation of the HGHE affected obviously the land surface temperature and the ground heat flux. The increase of the installation depth from 0.5 to 2 m increased the outlet temperatures. However, this increase was insignificant when the installation depth increased from 0.5 to 1 m. It was further identified that the non-consideration of the atmosphere-soil interaction overestimated the annual fluid outlet temperature in the heating scenario, and this overestimation decreased from 47.99% to 17.16% as the installation depth increased from 0.5 to 2 m. In conclusion, it is necessary to consider the atmosphere-soil interaction to predict precisely the outlet temperatures of a shallow HGHE.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Wind Engineering and Industrial Aerodynamics, Volume 192〈/p〉 〈p〉Author(s): A.J. Álvarez, F. Nieto, D.T. Nguyen, J.S. Owen, S. Hernández〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Vortex induced vibration (VIV) is an important phenomenon which appears in flexible structures immersed in a moving fluid. This oscillation is self-sustained and self-limited, but VIV might cause fatigue damage and affect the structure's serviceability.〈/p〉 〈p〉In the present study, the aerodynamics of the flow fields around a static and vertically free-to-oscillate 4:1 rectangular cylinder are analysed by means of 3D LES simulations, adopting the OneEqEddy viscosity model. Integral parameters, pressure distributions, amplitudes of oscillation, coherences and correlations are obtained and compared with the available experimental data. Aiming to ascertain the impact of the boundary conditions and the grid resolution on the accuracy of results, five cases adopting 3 different meshes including two different spanwise discretisations have been considered. When studying the aerodynamics of the cylinder in static conditions, the influence of the spatial discretisation is very limited, and the agreement with experimental data is fairly good. On the other hand, for the free-to-oscillate cylinder, the structural response is dramatically dependent on the spanwise discretisation. The maximum amplitude of the structural response decreases as the mesh resolution increases, providing a closer fit with the experimental data. Also, the spanwise correlation of pressures is studied, finding remarkable differences depending on the level of spatial discretisation.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Marine Systems, Volume 199〈/p〉 〈p〉Author(s): Peisheng Huang, Kerry Trayler, Benya Wang, Amina Saeed, Carolyn E. Oldham, Brendan Busch, Matthew R. Hipsey〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effective short- and long-term estuarine water quality management decisions require a holistic view of estuarine response to multiple stressors that may be achieved through the integration of numerical modelling and observed data. Such an approach has been developed for the Swan-Canning Estuary system, a eutrophic urban estuary in Western Australia under threat from nutrient enrichment and a drying climate. Numerical modelling was integrated with long-term monitoring to develop the system Swan-Canning Estuary Virtual Observatory (SCEVO), which has been used to facilitate water quality management and streamline prediction workflows of hindcast, forecast, and environmental response functions. The system is based on a validated 3D water quality model, integrated within a data management system and related environmental models. A machine-learning method to improve the patchy and time-lagged catchment inputs is also highlighted. This work has identified that the key challenge associated with estuarine water quality prediction is the capability to (1) simulate internal physical and biogeochemical processes at suitable spatial resolution to resolve the gradients along the freshwater-ocean continuum; and (2) transition from using routine monitoring data as the basis for management decisions to using a diverse and integrated set of data streams as the basis for real-time operational decisions. Recommendations for high-frequency monitoring to support water quality modelling and dynamic integration between numerical and observed data for improved forecasting are discussed.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Wind Engineering and Industrial Aerodynamics, Volume 192〈/p〉 〈p〉Author(s): Ali C. Kheirabadi, Ryozo Nagamune〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This article presents a review of control strategies for maximizing power production within wind farms. Discussions focus on three notable concepts; power de-rating, yaw-based wake redirection, and turbine repositioning. Existing works that have examined the potential of these concepts via optimization studies, numerical simulation, experimentation, as well as those that have developed and evaluated control algorithms, are reviewed thoroughly and quantitatively. Criteria for this review process include the evaluation methods employed, simulated wind conditions, controller properties such as model dependency and communication architecture, and the resulting relative rise in wind farm efficiency. The data collected from existing literature is then utilized to draw conclusions regarding the influence of each of these criteria on the potential and performance of wind farm controllers. Appropriate recommendations for future modeling and controller design research are then offered based on these conclusions.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Marine Systems, Volume 199〈/p〉 〈p〉Author(s): Arseny A. Kubryakov, Alexander S. Mikaelyan, Sergey V. Stanichny〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Bio-Argo measurements of the backscattering coefficient (〈em〉bbp〈/em〉) were used to investigate the time-depth evolution of coccolithophore blooms in the Black Sea. Five years of Bio-Argo data obtained in 2014–2018 revealed two distinct peaks of 〈em〉bbp〈/em〉 corresponding to the winter and early summer coccolithophore blooms. The latter started in the upper mixed layer (UML) in April–May and was characterized by the highest coccolithophore concentrations. During the most extensive summer bloom in 2017, its estimates reach 10 × 10〈sup〉6〈/sup〉 cells l〈sup〉−1〈/sup〉. The summer blooms occupied the UML (0–10 m) and a seasonal thermocline (10–30 m). The lower boundary of the bloom was related to the position of isopycnal 1014 kg m〈sup〉−3〈/sup〉, which deepens in May–July due to summer heating. Consequently, the coccolithophore bloom deepened to 20–30 m and terminated rapidly in July. Bloom termination was accompanied by a significant rise in light attenuation (〈em〉kd〈/em〉) in the sea basin. This peak was attributed to the release of dissolved organic carbon (DOC), which was possibly related to viral lysis and the exudation of lipids from coccolithophore cells. Data on the 〈em〉kd〈/em〉 was used to estimate the seasonal variability in DOC in the Black Sea. Maximal estimated values of DOC were observed at 15–35 m depth in June-August and coincided with the early summer coccolithophore bloom termination.〈/p〉 〈p〉The winter coccolithophore bloom started in October–November in the UML. The maximum 〈em〉bbp〈/em〉 was observed in January. High values of 〈em〉bbp〈/em〉 were observed down to a depth of 60 m during the maximal deepening of the mixed layer. The winter blooms were distinctly observed in MODIS satellite images, where they were characterized by high reflectance and relatively low chlorophyll concentrations. The estimated coccolithophore concentration in winter was lower than that in summer, but column-averaged 〈em〉bbp〈/em〉 values were comparable. The winter coccolithophore bloom reached a peak within one month after the autumn peak of chlorophyll A, indicating the possible importance of the nutrients recycled after the diatom autumn bloom. In contrast to summer, the maximum DOC observed at the surface preceded the winter coccolithophore bloom, and the mass DOC production was probably attributed to the excretion and lysis of the non-calcified phytoplankton cells.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Marine Systems, Volume 199〈/p〉 〈p〉Author(s): Yuanyi Li, Huan Feng, Haiwen Zhang, Jian Sun, Dekui Yuan, Lei Guo, Jing Nie, Jinglong Du〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The time required for water exchange characterizes the hydrodynamic condition of a water body, which is related to its self-purification ability. In this study, a numerical model based on a three-dimensional hydrodynamic model is established and implemented to calculate the age of water. Using the model, the spatial distribution and seasonal variation of the age of the water discharged into the New York/New Jersey (NY/NJ) Harbor from the Passaic River and the Hackensack River are calculated. The hydrodynamic conditions and the characteristics of water exchange in the harbor are analyzed from the perspective of age. The results indicate that the monthly-averaged age at the entrance of the NY/NJ Harbor is approximately 26 days and 40 days during the wet season and the dry season, respectively. River discharge has a significant impact on the spatial distribution of water age in the NY/NJ Harbor. Generally, high river discharge results in better water exchange and flushes contaminants out of the harbor quickly. However, discharges from several rivers flowing into the harbor interact and interfere with one another. Such interactions can improve or inhibit water and contaminant flushing from the harbor. The analysis of age variations and residual flows indicates that the Kill van Kull is one of the key channels controlling the contaminant transport and water quality in the Newark Bay. This study demonstrates the advantages of using water age to study the water exchange and physical self-purification ability of this complex harbor.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 235〈/p〉 〈p〉Author(s): Sanober Kahkashan, Xinhong Wang, Jianfang Chen, Youcheng Bai, Miaolei Ya, Yuling Wu, Yizhi Cai, Siquan Wang, Monawwar Saleem, Javed Aftab, Asif Inam〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perfluoroalkyl substances (PFAS) and organochlorine pesticides (OCPs) in surface sediments were investigated from the Bering Sea, the Chukchi Sea and adjacent Arctic Ocean in 2010. Total concentrations (dry weight) of Σ〈sub〉14〈/sub〉PFAS in surface sediments (0.85 ± 0.22 ng g〈sup〉−1〈/sup〉) of the Bering Sea were lower than that in the Chukchi Sea and adjacent Arctic Ocean (1.27 ± 0.53 ng g〈sup〉−1〈/sup〉). Perfluoro-butanoic acid (PFBS) and perfluoro-octanoic acid (PFOA) were the dominant PFAS in these areas. The concentrations of Σ〈sub〉15〈/sub〉OCPs in the sediment of the Bering Sea (13.00 ± 6.17 ng g〈sup〉−1〈/sup〉) was slightly higher than that in the Chukchi and Arctic Ocean (12.05 ± 2.27 ng g〈sup〉−1〈/sup〉). The most abundant OCPs were hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane (DDT) and its metabolites. The composition patterns of HCHs and DDTs indicated that they were mainly derived from the early residues via river runoff. Increasing trends of PFAS, HCHs and DDTs in surface sediments from the Bering Sea to the Arctic Ocean were found, indicating oceanic transport. In summary, the concentrations of OCPs were orders of magnitude greater than the observed PFAS concentrations, and the concentrations of PFAS and OCPs in surface sediments from the Bering Sea to the Chukchi Sea and adjacent Arctic Ocean are at the low to moderate levels by comparing with other coastal and marine sediments worldwide.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 235〈/p〉 〈p〉Author(s): Misganaw Alemu Zeleke, Dong-Hau Kuo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Methylene blue dye is among the toxic, mutagenic, and carcinogenic pollutants. Hence, its treatment via photocatalytic degradation is an important remediation method for the sake of a healthy environment. Herein, the V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉-CeO〈sub〉2〈/sub〉 nanocomposite catalysts were synthesized via a simple precipitation-thermal decomposition approach and used for the photodegradation of methylene blue in the presence of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 as an effective electron scavenger under visible light illumination. The nanocomposite catalysts were systematically characterized to investigate the effects of V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 with the aids of X-ray, morphology, light absorption, catalytic activity, and charge transfer properties of the nanocomposite catalysts. The VC-2 nanocomposite prepared with NH〈sub〉4〈/sub〉VO〈sub〉3〈/sub〉:CeO〈sub〉2〈/sub〉 molar ratios at 0.15:1 was found to be the best efficient catalyst where ≥98% of methylene blue was degraded within 25 min irradiation time. From the kinetics analysis, its rate constant was found to be higher than those of the pure V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 and CeO〈sub〉2〈/sub〉 catalysts by a factor of 12.0 and 13.5, respectively. The plausibly mechanistic elucidation of charge transfer and utilization of reactive species are conspicuous allegations of the combined effects of the nanocomposite catalyst, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 sacrificial agent, and visible light for the photodegradation of the dye.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653519314717-fx1.jpg" width="294" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Muhammad Abid, Muhammad Sajid Khan, Tahir Abdul Hussain Ratlamwala〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Parabolic dish solar collector system has capability to gain higher efficiency by converting solar radiations to thermal heat due to its higher concentration ratio. This paper examines the exergo-economic analysis, net work and hydrogen production rate by integrating the parabolic dish solar collector with two high temperature supercritical carbon dioxide (s-CO〈sub〉2〈/sub〉) recompression Brayton cycles. Pressurized water (H〈sub〉2〈/sub〉O) is used as a working fluid in the solar collector loop. The various input parameters (direct normal irradiance, ambient temperature, inlet temperature, turbine inlet temperature and minimum cycle temperature) are varied to analyze the effect on net power output, hydrogen production rate, integrated system energetic and exergetic efficiencies. The simulations has been carried out using engineering equation solver (EES). The outputs demonstrate that the net power output of the integrated reheat recompression s-CO〈sub〉2〈/sub〉 Brayton system is 3177 kW, whereas, without reheat integrated system has almost 1800 kW net work output. The overall energetic and exergetic efficiencies of former system is 30.37% and 32.7%, respectively and almost 11.6% higher than the later system. The hydrogen production rate of the solarized reheat and without reheat integrated systems is 0.0125 g/sec and 0.007 g/sec, accordingly and it increases with rise in direct normal irradiance and ambient temperature. The receiver has the highest exergy destruction rate (nearly 44%) among the system components. The levelized electricity cost (LEC) of 0.2831 $/kWh with payback period of 9.5 years has proved the economic feasibility of the system design. The increase in plant life from 10 to 32 years with 8% interest rate will decrease the LEC from (0.434-0.266) $/kWh. Recuperators have more potential for improvement and their cost rate of exergy is higher as compared to the other components.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Yuan Xue, Shixiong Min, Fang Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although black phosphorous (BP) and its derived materials have shown great potential for application in photocatalytic H〈sub〉2〈/sub〉 evolution reaction (HER), their HER activity and stability still remains unsatisfied mainly due to the insufficient charge separation, the lack of surface active sites, and the defect-riched nature of BP. Herein, we report that BP nanosheets decorated with in situ grown Pt (BP NSs/Pt) could act as a highly efficient catalyst for photocatalytic H〈sub〉2〈/sub〉 evolution in an Erythrosin B (ErB)-sensitized system under visible light irradiation (≥450 nm) in the presence of triethanolamine (TEOA) as sacrificial electron donor. It is found that BP NSs can provide large surface area for the confined growth of Pt nanoparticles with a high dispersion and a reduced size but also stabilize the loaded Pt nanoparticles by covalent bonds at the BP NSs/Pt interfaces. Moreover, BP NSs offer a fast electron transfer pathway to facilitate the photocatalytic HER over in situ grown Pt catalyst. As a result, BP NSs/Pt catalyst exhibits ∼6 times higher H〈sub〉2〈/sub〉 evolution activity than free Pt nanoparticles and an apparent quantum yield (AQY) of 0.57% at 500 nm irradiation in ErB-TEOA system. This work indicates the potential of BP NSs as an effective 2D matrix to construct numerous high performance photocatalysts and photocatalytic systems.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): C. Juillet, M. Tupin, F. Martin, Q. Auzoux, C. Berthinier, F. Miserque, F. Gaudier〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Under Pressurized Water Reactor normal operating conditions, the external surface of zirconium alloys cladding absorbs a fraction of the hydrogen produced by water reduction. During spent fuel transport, hydrogen may desorb from the cladding. The study aims to identify and quantify the rate-limiting step in the hydrogen desorption process initially present in the alloy. To better understand this process, the Thermal Desorption Spectrometry (TDS) was used in association with X-ray Photoelectron Spectroscopy analysis. TDS results were analysed with finite elements simulations using the Cast3M code. The optimization of the kinetic constants of hydrogen desorption was performed with CEA (Alternative Energies and Atomic Energy Commission)-tool URANIE. Results showed that hydrogen desorption kinetics from the metal is limited by the surface molecular recombination. Arrhenius-type temperature dependence of kinetic constants allowed to simulate experimental data with a good agreement. The optimized activation energy and the pre-exponential factor for desorption processes were in the range of 290 ± 10 kJ mol〈sup〉−1〈/sup〉 and 3 × 10〈sup〉7〈/sup〉 m〈sup〉4〈/sup〉 mol〈sup〉−1〈/sup〉 s〈sup〉−1〈/sup〉 respectively.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Abhishek Rajput, Prem P. Sharma, Vikrant Yadav, Vaibhav Kulshrestha〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Proton exchange membrane is a basic element for any redox flow battery. Nafion is the only commercial available proton exchange membrane used in different electro-chemical energy systems. High cost restrict it's used for energy generation devices. In present work, we synthesised styrene divinylbenzene based composite proton exchange membranes (PEMs) with varying sulfonated graphene oxide (sGO) content for redox flow battery (RFB). Synthesized copolymer PEMs were analyzed in terms of their chemical structure with the help of FT-IR spectroscopy to confirm desired functional groups at appropriate position. Electrochemical characterization was performed in terms proton-exchange capacity, protonic conductivity and water uptake. Membrane shows adequate proton exchange capacity with good proton conductivity. Vanadium ion permeability was also tested for the prepared membrane to assess capability for vanadium redox flow battery (VRFB) in contrast with commercially available Nafion 117 PEM. Higher VO〈sup〉+2〈/sup〉 ion cross-over resistance was found for CEM-4 with 7.17 × 10〈sup〉−7〈/sup〉 cm〈sup〉2〈/sup〉 min〈sup〉−1〈/sup〉 permeability, which is about half of the CEM-1. Further CEM-4 was also evaluated for charging-discharging phenomenon for single cell VRFB. The values of columbic, voltage and energy efficiency for VRFB confirms prepared membrane as a good candidate for redox flow battery. Composite PEM also shows better mechanical and thermal stability. Results indicates that synthesized composite membrane can be used in vanadium redox flow battery.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0360319919323584-fx1.jpg" width="395" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Marie-Ange Massicotte, Antony T. Vincent, Anna Schneider, Valérie E. Paquet, Michel Frenette, Steve J. Charette〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Gram-negative bacterium 〈em〉Aeromonas salmonicida〈/em〉 subsp. 〈em〉salmonicida〈/em〉 is an aquatic pathogen which causes furunculosis to salmonids, especially in fish farms. The emergence of strains of this bacterium exhibiting antibiotic resistance is increasing, limiting the effectiveness of antibiotherapy as a treatment against this worldwide disease. In the present study, we discovered an isolate of 〈em〉A. salmonicida〈/em〉 subsp. 〈em〉salmonicida〈/em〉 that harbors two novel plasmids variants carrying antibiotic resistance genes. The use of long-read sequencing (PacBio) allowed us to fully characterize those variants, named pAsa5-3432 and pRAS3-3432, which both differ from their classic counterpart through their content in mobile genetic elements. The plasmid pAsa5-3432 carries a new multidrug region composed of multiple mobile genetic elements, including a Class 1 integron similar to an integrated element of 〈em〉Salmonella enterica〈/em〉. With this new region, probably acquired through plasmid recombination, pAsa5-3432 is the first reported plasmid of this bacterium that bears both an essential virulence factor (the type three secretion system) and multiple antibiotic resistance genes. As for pRAS3-3432, compared to the classic pRAS3, it carries a new mobile element that has only been identified in 〈em〉Chlamydia suis〈/em〉. Hence, with the identification of those two novel plasmids harboring mobile genetic elements that are normally encountered in other bacterial species, the present study puts emphasis on the important impact of mobile genetic elements in the genomic plasticity of 〈em〉A. salmonicida〈/em〉 subsp. 〈em〉salmonicida〈/em〉 and suggests that this aquatic bacterium could be an important reservoir of antibiotic resistance genes that can be exchanged with other bacteria, including human and animal pathogens.〈/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-S0048969719330293-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 689〈/p〉 〈p〉Author(s): Christopher Markosian, Natella Mirzoyan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pollution by heavy metals and metalloids is detrimental to human health due to their toxic, genotoxic, and carcinogenic effects. The traditional approach to assess the extent of environmental and occupational exposures of metals is human biomonitoring (HBM). This method has several limitations, including invasiveness, sampling bias, cost- and time-intensiveness, and ethical issues. This suggests the need for a more robust, non-invasive, epidemiological tool for assessment of exposure to metals and their public health effects. Recently, wastewater-based epidemiology (WBE) has been suggested and utilized as a novel approach to accurately determine the extent of exposure to multiple substances on the population level. We suggest the potential application of WBE to the study of metal exposure on the population level, including possible biomarkers for wastewater analysis of 10 metals belonging to three categories according to health effects and nutritional benefits, and its public health implications. Similar to previous studies of exposure to regulated or illegal drugs, unregulated legal substances, and pesticides, WBE can be applied to the study of metal exposure in a given community. Parental substance biomarkers (PSBs), metabolic substance biomarkers (MSBs), and non-substance biomarkers (NSBs) of 10 common metals are available for consideration in wastewater analysis. The use of WBE would allow for the interpretation of the relationship between metal exposure and population health, reveal synergistic effects of different health factors, and model public health risks under different scenarios.〈/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-S0048969719329924-ga1.jpg" width="459" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Yong-Lin Liu, Yong-Tao Li, Jian-Fei Huang, Yu-Long Zhang, Zhong-Hang Ruan, Tian Hu, Jin-Jin Wang, Wen-Yan Li, Han-Jian Hu, Gang-Biao Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The application of iron oxide nanoparticles (IONs) is often limited by agglomeration and low loading. Here, we presented a facile phase change material (PCM) -based sol-gel strategy for the fabrication of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles. Rosin was used as the PCM in the sol-gel process and the carbon-based substrate of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles in the thermal process. The α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticle embedded rosin-derived biochar(α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@HrBc)were highly dispersed. The dispersity of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticle could be regulated by the weight ratios of rosin to FeCl〈sub〉3〈/sub〉·6H〈sub〉2〈/sub〉O during the preparation, as evidenced by the scanning electron microscope (SEM) spectrum and the sorption capacity results. Among a series of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@HrBc nanocomposites, the one with the weight ratios of 1/1.5 rosin/FeCl〈sub〉3〈/sub〉·6H〈sub〉2〈/sub〉O had the highest capacity for hexavalent chromium (Cr(VI)) sorption. This phenomenon can be ascribed to a remarkably enhanced interfacial reactivity due to an increase in the dispersity of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticle. In addition, SEM showed that the majority of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles was dispersed on and inside the biochar substrate. Batch adsorption experiments revealed that the α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@HrBc adsorbed 90% Cr(VI) within one minute, and the maximum capacity was up to 166 mg·g〈sup〉−1〈/sup〉 based on the Langmuir model. The FTIR and XPS spectra revealed that the adsorbed Cr(VI) species were partially reduced to less toxic Cr(III). Considering that α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles provided important sorption sites, the newly formed Cr(III) and the remaining Cr(VI) ions could be adsorbed on α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@HrBc via the formation of Fe〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Cr coprecipitation.〈/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-S0048969719331341-ga1.jpg" width="351" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 689〈/p〉 〈p〉Author(s): Lei Zhang, Zhen Shen, Wangkai Fang, Guang Gao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efforts to understand the environmental and biological factors that influence the dynamics of microbial communities have received substantial attention in microbial ecology. In this study, Illumina MiSeq high-throughput sequencing technology was used to examine the microbial community structure of activated sludge in municipal wastewater treatment systems (Chuzhou city, China). Overall, 〈em〉Proteobacteria〈/em〉, 〈em〉Chloroflexi〈/em〉, 〈em〉Actinobacteria〈/em〉, 〈em〉Acidobacteria〈/em〉, 〈em〉Actinobacteria〈/em〉, 〈em〉Bacteroidetes〈/em〉, and 〈em〉Firmicutes〈/em〉 were the most dominant phyla in the five activated sludge samples. However, the community structure of nitrifying bacteria was relatively simple, and diversity was low; only AOB (〈em〉Nitrosomonas〈/em〉) and NOB (〈em〉Nitrospira〈/em〉) were detected. The dominant bacteria in the anaerobic sludge, anoxic sludge and oxic sludge were the same, and each bacterial species was relatively uniform, with differences only in proportions. Redundancy analysis indicated that pH, TP and COD were strong environmental factors influencing the bacterial community distribution. PICRUSt was used to describe the metabolic and functional abilities of the activated sludge bacterial communities. The results emphasized the vast genetic diversity of these organisms, which are involved in various essential processes such as amino acid transport and metabolism, energy production and conversion, cell wall/membrane/envelope/biogenesis, signal transduction mechanisms, and carbohydrate transport and metabolism. Activated sludge of municipal wastewater treatment systems can be ranked in the following order based on the 16S rRNA gene copy numbers of the detected phylotypes: S1 〉 S2 〉 S4 〉 S5 〉 S3. This study provides basic data and a theoretical analysis of the optimal design and operation in wastewater treatment plants.〈/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-S0048969719330050-ga1.jpg" width="285" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Zhanfei He, Qingying Zhang, Zhen Wei, Yuanhai Zhao, Xiangliang Pan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Organic micropollutants (OMPs) are frequently detected in water and wastewater, and have attracted wide attention due to potential adverse effects on ecosystems and human health. In this work, manganese-oxidizing aerobic granular sludge (Mn-AGS) was successfully cultivated and applied to remove OMPs from wastewater. Biogenic manganese (III,IV) oxides (bio-MnO〈sub〉x〈/sub〉) were generated and accumulated to 22.0–28.3 mg Mn/g SS in the final sludge. Neither the addition of allochthonous manganese-oxidizing bacteria (MnOB; 〈em〉Pseudomonas putida〈/em〉 MnB1) nor the reduction in hydraulic retention time (HRT) facilitated the cultivation of Mn-AGS. Batch experiments of OMPs degradation indicated that Mn-AGS significantly improved (1.3–3.9 times) degradation rates of most OMPs. Removal rates of bisphenol A (BPA), 17α‑ethinylestradiol (EE2), tetracycline (TC), and chloramphenicol (CAP) were 3.0–12.6 μg/h/g SS by the traditional AGS and 8.0–16.3 μg/h/g SS by Mn-AGS; those of imazethapyr (IM) were relatively high, 64.7 ± 0.1 and 127.8 ± 2.5 μg/h/g SS by AGS and Mn-AGS, respectively. However, degradation of dichlorophenyl phosphine (DCPP) was slower by Mn-AGS than AGS, 9.0 ± 0.4 vs. 21.2 ± 0.9 μg/h/g SS, possibly due to inhibition of microbial activity by bio-MnO〈sub〉x〈/sub〉. This work provides a promising method for treating OMPs in organic wastewater, but the possible inhibition of microbes by bio-MnO〈sub〉x〈/sub〉 should be noted.〈/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-S0048969719330827-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Alexander Johs, Virginia A. Eller, Tonia L. Mehlhorn, Scott C. Brooks, David P. Harper, Melanie A. Mayes, Eric M. Pierce, Mark J. Peterson〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mercury (Hg) contamination of soils and sediments impacts numerous environments worldwide and constitutes a challenging remediation problem. In this study, we evaluate the impact of dissolved organic matter (DOM) on the effectiveness of eight sorbent materials considered for Hg remediation in soils and sediments. The materials include both engineered and unmodified materials based on carbon, clays, mesoporous silica and a copper alloy. Initially, we investigated the kinetics of Hg(II) complexation with DOM for a series of Hg:DOM ratios. Steady-state Hg-DOM complexation occurred within 48 to 120 h, taking longer time at higher Hg:DOC (dissolved organic carbon) molar ratios. In subsequent equilibrium experiments, Hg(II) was equilibrated with DOM at a defined Hg:DOC molar ratio (2.4 · 10〈sup〉−6〈/sup〉) for 170 h and used in batch experiments to determine the effect of DOM on Hg partition coefficients and sorption isotherms by comparing Hg(II) and Hg-DOM. Hg sorption capacities of all sorbents were severely limited in the presence of DOM as a competing ligand. Thiol-SAMMS®, SediMite™ and pine biochar were most effective in reducing Hg concentrations. While pine biochar and lignin-derived carbon processed at high temperatures released negligible amounts of anions into solution, leaching of sulfate and chloride was observed for most engineered sorbent materials. Sulfate may stimulate microbial communities harboring sulfate reducing bacteria, which are considered one of the primary drivers of microbial mercury methylation in the environment. The results highlight potential challenges arising from the application of sorbents for Hg remediation in the field.〈/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-S0048969719331146-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 689〈/p〉 〈p〉Author(s): Min Xu, Robert D. Stedtfeld, Fang Wang, Syed A. Hashsham, Yang Song, Yahui Chuang, Jianbo Fan, Hui Li, Xin Jiang, James M. Tiedje〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different long-term fertilization regimes may change indigenous microorganism diversity in the arable soil and thus might influence the persistence and transmission of manure-born antibiotic resistance genes (ARGs). Different manure origins and composting techniques might affect the fate of introduced ARGs in farmland. A four-month microcosm experiment was performed using two soils, which originated from the same field and applied with the same chemical fertilizer or swine manure for 26 years, to investigate the dynamics of ARGs in soil amended with manure or compost from the farm and an agro-technology company. High throughput qPCR and sequencing were applied to quantify ARGs using 144 primer sets and microorganism in soil. Fertilization history had little effect on dynamics of manure-borne ARGs in soil regardless of manure origin or composting. Very different half-lives of ARGs and mobile genetic elements from farm manure and commercial manure were observed in both soils. Composting decreased abundance of most ARGs in manure, but increased the persistence of manure-introduced ARGs in soil irrespective of fertilization history, especially for those from farm manure. These findings help understanding the fate of ARGs in manured soil and may inform techniques to mitigate ARGs transmission.〈/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-S0048969719329493-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Md. Siddiqur Rahman, Abu Reza Md. Towfiqul Islam〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A comprehensive understanding of the changing behaviors of precipitation concentration and intensity plays a pivotal role in water resource management. Hence, we investigated the spatiotemporal changing behaviors of frequency and intensity of 13 precipitation indices and their probable causes of changes in precipitation systems. This study used daily precipitation datasets from 23 sites in Bangladesh and six atmospheric circulation indices during 1975–2017. The results showed that the precipitation concentration index (LCI) varies between 0.57 and 0.63, and the highest value was found in the southeastern region. The precipitation days frequency indices such as AD, LPD, MPD, HPD, and WPD have significantly increased in Bangladesh while precipitation intensity indices such as AII, LPI, MPI, HPI, and WPI have significantly declined; all types of indices have clear rapid changes. The results of detrended fluctuation analysis (DFA) exhibit long-term correlations among all precipitation indices, suggesting that these indices will sustain their present trend line in the upcoming period. The Sunspot (SS) and East Asian Summer Monsoon Index (EASMI) had a negative influence on ACI and South Asian Summer Monsoon index (SASMI) had a strong positive influence on precipitation days frequency indices. The significance analysis using the random forest (RF) algorithm showed that SS is the largest contributing factor affecting the precipitation systems in Bangladesh. ECMWF ERA5 reanalysis datasets revealed that elevating summer geopotential height, higher anticyclonic anomaly, increasing low and decreasing high cloud covers and lower solar radiation with adequate moisture divergence fluxes contributed to variations in precipitation extremes in Bangladesh.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Linear trend of Arid days, AD (a), Sequential Mann-kendall test to detect rapid change (b), DFA long term forecasting of ACI (c) and Cross wavelet between SASMI and ACI (d).〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0048969719330980-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Bláthnaid M. Mahon, Carina Brehony, Niamh Cahill, Elaine McGrath, Louise O'Connor, Aine Varley, Martin Cormican, Sinead Ryan, Paul Hickey, Shane Keane, Martina Mulligan, Bryan Ruane, Keith A. Jolley, Martin C. Maiden, Sylvain Brisse, Dearbháile Morris〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The rapid dissemination of carbapenemase-producing 〈em〉Enterobacterales〈/em〉 (CPE) is a major public health concern. The role that the aquatic environment plays in this dissemination is underexplored. This study aimed to examine seawater as a reservoir for CPE. Seawater sampling took place at a bathing site throughout the 2017 bathing season. Each 30 L sample (〈em〉n〈/em〉 = 6) was filtered using the CapE filtration system. Wastewater samples (200 mL) (pre-treatment (〈em〉n〈/em〉 = 3) and post-treatment (n = 3)) were obtained from a nearby secondary wastewater treatment plant, during the same time period. All samples were examined for CPE. Whole genome sequencing of confirmed CPE was carried out using Illumina sequencing. Isolate genomes were hosted in corresponding BIGSdb databases and analyses were performed using multiple web-based tools. CPE was detected in 2/6 seawater samples. It was not detected in any wastewater samples. OXA-48-like-producing ST131 〈em〉Escherichia coli〈/em〉 (Ec_BM707) was isolated from a seawater sample collected in May 2017 and OXA-48-like-producing ST101 〈em〉Klebsiella pneumoniae〈/em〉 (Kp_BM758) was isolated from a seawater sample collected in August 2017. The genomes of the environmental isolates were compared to a collection of previously described Irish clinical OXA-48-like-producing 〈em〉Enterobacterales〈/em〉 (〈em〉n〈/em〉 = 105). Ec_BM707 and Kp_BM758 harboured 〈em〉bla〈/em〉〈sub〉OXA-48〈/sub〉 on similar mobile genetic elements to those identified in the clinical collection (pOXA-48 fragment in Ec_BM707 and IncL(pOXA-48) plasmid in Kp_BM758). Genetic similarities were observed between Ec_BM707 and several of the clinical ST131 〈em〉E. coli,〈/em〉 with allele matches at up to 98.2% of 2513 core genome multilocus sequence type (cgMLST) loci. In contrast, Kp_BM758 and the 34 clinical 〈em〉K. pneumoniae〈/em〉 were genetically distant. The source of the CPE at this site was not identified. The detection of OXA-48-like-producing ST131 〈em〉E. coli〈/em〉 and OXA-48-like-producing ST101 〈em〉K. pneumoniae〈/em〉 in Irish recreational water is a concern. The potential for contamination of the aquatic environment to contribute to dissemination of CPE in Europe warrants further study.〈/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-S0048969719330542-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Zhenyi Chen, Robyn Schofield, Peter Rayner, Tianshu Zhang, Cheng Liu, Claire Vincent, Sonya Fiddes, Robert George Ryan, Joel Alroe, Zoran D. Ristovski, Ruhi S. Humphries, Melita D. Keywood, Jason Ward, Clare Paton-Walsh, Travis Naylor, Xiaowen Shu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The rapid environmental changes in Australia prompt a more thorough investigation of the influence of transportation, local emissions, and optical–chemical properties on aerosol production across the region. A month-long intensive measurement campaign was conducted during spring 2016 at Mission Beach, a remote coastal site west of the Great Barrier Reef (GBR) on the north-east coast of Australia. One aerosol pollution episode was investigated in early October. This event was governed by meteorological conditions and characterized by the increase in black carbon (BC) mass concentration (averaged value of 0.35 ± 0.20 μg m〈sup〉−3〈/sup〉). Under the influence of the continental transportation, a new layer of nucleation-mode aerosols with an initial size diameter of 20 nm was observed and aerosol number concentrations reached the peak of 6733 cm〈sup〉−3〈/sup〉 at a diameter of 29 nm. The averaged aerosol extinction coefficient at the height of 2 km was 150 Mm〈sup〉−1〈/sup〉, with a small depolarized ratio (3.5–5%). Simultaneously, the boundary layer height presented a fall–rise trend in the presence of these enhanced aerosol concentrations and became stable in a later stage of the episode. We did not observe clear boundary layer height diurnal variations from the LiDAR observations or from the Weather Research and Forecasting (WRF) model outputs, except in an earlier stage of the aerosol episode for the former. Although the sea breeze may have been responsible for these particles, on the balance of available data, we suggest that the aerosol properties at the GBR surface during this period are more likely influenced by regional transportation of continental sources, including biomass-burning aerosols.〈/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-S0048969719331201-ga1.jpg" width="326" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Pau Batlle-Vilanova, Laura Rovira-Alsina, Sebastià Puig, M. Dolors Balaguer, Pilar Icaran, Victor M. Monsalvo, Frank Rogalla, Jesús Colprim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Biogas production in wastewater treatment plants (WWTPs) plays a decisive role in the reduction of CO〈sub〉2〈/sub〉 emissions and energy needs in the context of the water-energy nexus. The biogas obtained from sewage sludge digestion can be converted into biomethane by the use of biogas upgrading technologies. In this regard, an innovative water scrubbing based technology, known as ABAD Bioenergy® is presented and considered in this work. The effluents resulting from this system consist of biomethane and treated wastewater with a high CO〈sub〉2〈/sub〉 concentration. Therefore, the study explores the feasibility of using this CO〈sub〉2〈/sub〉-containing effluent in the cathode of a bioelectrochemical system (BES) for the transformation of CO〈sub〉2〈/sub〉 into methane. Techno-economic assessment of the process is presented, including the valorisation of anode reactions through the production of chlorine compounds. Finally, the potential impacts of applying this technology in a WWTP operated by FCC Aqualia are (i) increasing biomethane production by 17.4%, (ii) decreasing CO〈sub〉2〈/sub〉 content by 42.8% and (iii) producing over 60 ppm of chlorine compounds to disinfect all the treated wastewater of the plant.〈/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-S0048969719329341-ga1.jpg" width="265" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 10 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 690〈/p〉 〈p〉Author(s): Muhammad Bilal, Hafiz M.N. Iqbal〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Steroidal estrogens are widespread water contaminants with potential carcinogenic and endocrine-disrupting activities. The World Health Organization has listed estrogens as group 1 carcinogens. These contaminants are of substantial concern because of potential threats to human health, and aquatic organisms on long-term exposure. A range of methods, including oxidation, adsorption, electrochemical, and irradiation techniques have been employed for their remediation from aqueous systems. However, inadequate removal, toxic sludge generation, high operating costs, and the requisite for skilled operating and maintenance personnel commercially hampered the application of many methods. An interesting alternative treatment approach based on the use of oxidoreductases, particularly laccases, has recently gained amicability for the biotransformation of emerging pollutants. The use of immobilized enzymes is more cost-effective from an industrial perspective due to improved catalytic stability, reusability, reduction of product inhibition, and easier product separation. This review provides comprehensive knowledge on the use of laccases in the biodegradation of steroidal estrogens, including estrone, 17〈em〉β〈/em〉-estradiol, and 17〈em〉α〈/em〉-ethinylestradiol with endocrine-disrupting potency from the environment. After an overview of estrogens and catalytic properties of laccase, the use of free, as well as immobilized laccases with a particular emphasis on estrogens removal by laccase-based fed-batch, packed bed bioreactors, and membrane reactors, is discussed. A comparison of existing treatment technologies with enzyme technology for the removal of estrogens from different environmental matrices is made. Lastly, along with concluding remarks, future research direction aimed at bridging knowledge gaps for estrogenic compounds removal are also proposed in this very important research area.〈/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-S0048969719331389-ga1.jpg" width="227" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ecological Engineering, Volume 136〈/p〉 〈p〉Author(s): Ramón Perea, Jessica S. Cunha, Cristiani Spadeto, Vanessa M. Gomes, Arthur L. Moura, Bárbara Rúbia, G. Wilson Fernandes〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Roads are known to be a major factor in the ongoing spread and establishment of invasive plants by modifying habitats and providing movement corridors. Controlling plant invasion or restoring highly-invaded areas along roads is a challenging task in current conservation practice. We aim to investigate the possible facilitative effects of nurse shrubs on native vs. exotic species in order to provide applications for conservation and restoration of highly invaded roadsides areas in megadiverse montane areas of Brazil. We estimated the abundance of each plant species (native and exotic) in paired roadsides with and without pioneer nurse shrubs (〈em〉Baccharis〈/em〉 spp.), and measured whether they were facilitated (i.e., growing underneath native nurse shrubs), using a Facilitation Value metric. We found that the proportion of exotic species was 27% greater in areas without the nurse shrubs. In addition, predicted probability of nurse shrubs as facilitators of native species was 61% greater than that of exotic species. Pioneer nurse shrubs that alleviate the environmental shift generated by the construction and use of roads (e.g., disturbed soils with low nutrient content) may represent an interesting alternative to mitigate exotic plant invasion along roadsides, a current global priority for biodiversity conservation. Decision-makers considering whether to build, improve, and maintain roads should take into account the potential spread of exotic plants and the use of nurse shrubs to prevent or mitigate plant invasiveness.〈/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-S0925857419302216-ga1.jpg" width="263" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: July–August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Today, Volume 27〈/p〉 〈p〉Author(s): George F. Vander Voort〈/p〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Hiral D. Shah, J.A. Bhalodia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this communication, we report the structural and electrical transport properties of (1-〈em〉x〈/em〉) La〈sub〉0.7〈/sub〉Sr〈sub〉0.3〈/sub〉Mn〈sub〉0.95〈/sub〉Co〈sub〉0.05〈/sub〉O〈sub〉3〈/sub〉 (LSMCO) + (〈em〉x〈/em〉) ZnO (〈em〉x〈/em〉 = 0%, 6%, 9%, 12%, 15% & 18%) composites. For the preparation of (1-〈em〉x〈/em〉) LSMCO + (〈em〉x〈/em〉) ZnO (〈em〉x〈/em〉 = 6%, 9%, 12%, 15% & 18%) composites, sample of LSMCO was prepared by the auto combustion technique/inexpensive modified sol-gel technique. The results of Rietveld refined XRD data show that LSMCO sample possesses a rhombohedral structure with the 〈em〉R-3c〈/em〉 space group whereas ZnO compound remains with hexagonal structure with the 〈em〉P6〈/em〉〈sub〉〈em〉3〈/em〉〈/sub〉〈em〉mc〈/em〉 space group in all the composite samples. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that no any extra unwanted phase was observed in each composite excluding the LSMCO and ZnO phases. ZnO is mostly distributed at the grain boundaries and on the surface of the LSMCO grains. Elemental presence and ratio was confirmed through the EDX analysis. The electrical resistivity of LSMCO and each composite was measured in the temperature range of 2 K–320 K at 0 Oe, 10 kOe, 50 kOe & 90 kOe magnetic field. The results indicate that the ZnO addition increases the resistivity of all the composites compare to that of pure LSMCO. The electrical resistivity explored by the theoretical model below 〈em〉T〈/em〉〈sub〉MI〈/sub〉 and fitting enlightenment for the observed behavior is transmitted here in detail.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Dezhi Yang, Weihua Liu, Dingfu Cheng, Jieshi Chen, Hao Lu, Chun Yu, Jijin Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉(Co, Cr)23C6 type carbide is a typical metallic compound in many cobalt bearing alloys, and it acts as the strengthening phase in the form of bulk eutectic carbides or precipitated carbides. In this work, first-principles calculations were carried out to investigate the electronic structure, phase stability, mechanical and magnetic properties of (Co, Cr)23C6 with different cobalt occupation. Some of the calculated values are compared with previous studies and, they are found to be in a good agreement. The method considering curvature radius is firstly used to describe the degree of anisotropy. The hardness calculated through elastic constants presents an approximate downtrend with the cobalt concentration. Analysis of the density of states (DOS), overlapped population and electron density maps, indicates that the bonds in (Co, Cr)23C6 are the mixture of covalent, ionic and metallic bonds, the interactions of 〈em〉d-d〈/em〉 orbits between metallic atoms contribute most to the hybridization mode. According to the population analysis, the reduction in hardness can attribute to the increase of metallicity and iconicity of the interacted metallic atoms. In addition, the formation of a large quantity of antibonding also plays a negative role in intrinsic hardness of (Co, Cr)23C6 when massive substitution of cobalt atom.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Morteza Alizadeh, Andisheh Shakery, Erfan Salahinejad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this research, the structure and mechanical properties of 1050 aluminum strips reinforced with E-glass fibers, processed by the cross accumulative roll bonding (CARB) process, were investigated from microscopic, hardness, tensile and peeling viewpoints. The results indicated that the incorporation of the glass fibers in the Al matrix increases strength and micro-hardness but decreases elongation. In addition, it was realized that some of these fibers are broken and changed to short fibers during the CARB process. The presence of the glass fibers strongly also reduces the bond efficiency of the Al strips, typically from 50% to 5%. To compensate this deleterious effect, it was found that at least 25% should be increased to the normal thickness reduction used in CRAB.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 9 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Acta Astronautica〈/p〉 〈p〉Author(s): Bing Xiong, Xiao-qiang Fan, Yi Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To improve the performance of a hypersonic inward turning inlet, an optimization design method was proposed. A parameterization methodology was developed for an axisymmetric basic flowfield, and the geometry of a basic flowfield can be easily generated in several parameters. Preliminarily, an optimization targeting on the basic flowfield performance was conducted. As a result, the total pressure recovery of the basic flowfield was improved 7.65% compared with the referred one under the same constraints. The corresponding stream-traced inlet performance was also improved 5.65%. For further optimization, an optimization directly targeting on the 3-D inlet performance was carried out. The method of calculating along streamlines (MCS), which is for the fast calculation of a stream-traced inlet flowfield, was proposed and confirmed before this optimization. The result shows that the 3-D inlet total pressure can be further enhanced 6.74% than the previous one, and it is 12.78% higher than the referred one. That is to say, it is more reasonable to target on the inlet performance directly for an optimization, rather than targeting on the basic flowfield performance. By statistically analyzing the optimization data, it was found that the opinion “A better basic flowfield means a better stream-traced inlet” is statistically correct, but not exactly correct. The steam-traced inlet performance is not exactly determined by a basic flowfield, and it is determined by a combination of all the flow tubes the inlet captures.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): Naser Abdi, Yaser Abdi, Zahra Alemipour〈/p〉

Beschreibung: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): Smajil Halilovic, Jamie M. Bright, Wiebke Herzberg, Sven Killinger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Knowledge of horizontal solar irradiance is crucial for the nowcasting and forecasting of generated photovoltaic (PV) power. High quality irradiance measurement devices, however, are typically not collocated with PV systems. The lack of measurements can be compensated by numerical weather models or satellite-derived products, but they provide only limited temporal and spatial resolutions. Another possibility is to directly use PV systems as irradiance sensors, since the measured PV power is a good indicator of incoming solar irradiance. The challenging part in this procedure is the computation of the global horizontal irradiance 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si233.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉h〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 from the global tilted irradiance 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si234.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉c〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉, because a combination of decomposition and transposition models is not analytically invertible. Hence, the majority of existing solutions to this problem are numerical procedures. In this paper, an analytical approach to compute 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si235.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉h〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si236.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉c〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 is presented. The comparison of the proposed approach with one of the existing iterative (numerical) approaches shows promising results. When applied to 1-min data at four different locations, the new approach outperforms the iterative procedure by up to 9% in terms of the relative root mean square error (rRMSE) for east/west module’s orientations, and performs slightly better with the south orientation. Moreover, the new approach provides results in less than 1 s, whereas the iterative procedure requires more than 20 min for a one year of data. An open source R-script of the new approach is also publicly available and provided as supplementary material.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Water Research, Volume 162〈/p〉 〈p〉Author(s): Marine Diana, Mónica Felipe-Sotelo, Tom Bond〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Epidemiological studies have consistently associated the consumption of chlorinated drinking water with an enhanced risk of bladder cancer. While this suggests that some disinfection byproducts (DBPs) are bladder carcinogens, causal agents are unknown. This study aims to highlight likely candidates. To achieve this, structures of known and hypothesised DBPs were compared with 76 known bladder carcinogens. The latter are dominated by nitrogenous and aromatic compounds; only 10 are halogenated. Under 10% of the chlorine applied during drinking water treatment is converted into identified halogenated byproducts; most of the chlorine is likely to be consumed during the generation of unidentified non-halogenated oxidation products. Six nitrosamines are among the nine most potent bladder carcinogens, and two of them are known to be DBPs: N-nitrosodiphenylamine and nitrosodibutylamine. However, these and other nitrosamines are formed in insufficiently low concentrations in chlorinated drinking water to account for the observed bladder cancer risk. Furthermore, although not proven bladder carcinogens, certain amines, haloamides, halocyclopentenoic acids, furans and haloquinones are potential candidates. At present, most identified bladder carcinogens are nitrogenous, whereas 〉90% of natural organic matter is not. Therefore, non-nitrogenous DBPs are likely to contribute to the bladder cancer risk. Given the high proportion of DBPs that remains uncharacterised, it is important that future research prioritises compounds believed to be potent toxicants.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S004313541930613X-fx1.jpg" width="354" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): Jean-Lou Pfister, Olivier Marquet, Marco Carini〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stability analysis of elastic structures strongly coupled to incompressible viscous flows is investigated in this paper, based on a linearization of the governing equations formulated with the Arbitrary-Lagrangian–Eulerian method. The exact linearized formulation, previously derived to solve the unsteady non-linear equations with implicit temporal schemes, is used here to determine the physical linear stability of steady states. Once discretized with a standard finite-element method based on Lagrange elements, the leading eigenvalues/eigenmodes of the linearized operator are computed for three configurations representative for classical fluid–structure interaction instabilities: the vortex-induced vibrations of an elastic plate clamped to the rear of a rigid cylinder, the flutter instability of a flag immersed in a channel flow and the vortex shedding behind a three-dimensional plate bent by the steady flow. The results are in good agreement with instability thresholds reported in the literature and obtained with time-marching simulations, at a much lower computational cost. To further decrease this computational cost, the equations governing the solid perturbations are projected onto a reduced basis of free-vibration modes. This projection allows to eliminate the extension perturbation, a non-physical variable introduced in the ALE formalism to propagate the infinitesimal displacement of the fluid–solid interface into the fluid domain.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ultramicroscopy, Volume 206〈/p〉 〈p〉Author(s): P. Kükelhan, T. Hepp, S. Firoozabadi, A. Beyer, K. Volz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantitative scanning transmission electron microscopy (STEM) is a powerful tool for the characterization of nano-materials. Absolute composition determination for ternary III–V semiconductors by direct comparison of experiment and simulation is well established. Here, we show a method to determine the composition of quaternary III–V semiconductors with two elements on each sub lattice from the intensities of one STEM image. As an example, this is applied to (GaIn)(AsBi). The feasibility of the method is shown in a simulation study that also explores the influence of detector angles and specimen thickness. Additionally, the method is applied to an experimental STEM image of a (GaIn)(AsBi) quantum well grown by metal organic vapour phase epitaxy. The obtained concentrations are in good agreement with X-ray diffraction and photoluminescence results.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: July–August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Today, Volume 27〈/p〉 〈p〉Author(s): Laurie Donaldson〈/p〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 254〈/p〉 〈p〉Author(s): Zhi-Hu Wang, Hong-Wei He, Guo-Sai Liu, Xu Yan, Xin Ning, Yun-Ze Long〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In conventional electrospinning (e-spinning) process, the curing mechanism can be attributed to the volatilization of solvent or the melt cooling of the jets, which were merely physical processes. To develop novel e-spinning curing mechanism, we propose a conjugate e-spinning one, in which the e-spinning precursors, solution A containing some active monomers, oxidant and solution B containing reductant, are loaded into two different syringes connected with opposite high voltage supplier, respectively. The opposite charged jets attract each other and then meet when flying from spinneret tip to collector. The redox reaction occurs when two jets meet and radicals are produced in situ which can initiate polymerization of active monomers. Then the conjugate jets solidify into fibers under reaction curing mechanism. The new method may give a new approach to produce composite functional fibers.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Two solutions containing oxidant and reductant, respectively are electrospun into fibers via a conjugate electrospinning process under a reaction curing mechanism.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0167577X19309954-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): J.Y. Oh, Tien M. Le, A.T. Pham, D.H. Tran, D.S. Yang, B. Kang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we investigated a correlation between superconductivity and interlayer coupling of two different alkaline (Na and K)-substituted Bi〈sub〉1·6〈/sub〉Pb〈sub〉0·4〈/sub〉Sr〈sub〉2〈/sub〉Ca〈sub〉2〈/sub〉Cu〈sub〉3〈/sub〉O〈sub〉10+δ〈/sub〉 (BSCCO) polycrystalline samples. The excess conductivity analysis by the Aslamazov-Larkin (AL) and Lawrence-Doniach (LD) theories showed that Na substitution at the Ca site induced a gradual broadening of 3D fluctuation region with increasing interlayer coupling strength, which explains a systematic increase of 〈em〉T〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 and a decrease of normal state resistivity. On the other hand, exactly the opposite results were observed in the K-substituted samples in place of Sr. Extended x-ray absorption fine structure (EXAFS) studies revealed that substitution of Na and K generated completely different effects on the local structure around Cu atoms. It is noticeable that the Cu–O bond distance was found to decrease monotonically with the varying amounts of Na, which indicates that the CuO〈sub〉2〈/sub〉 layer is stabilized. On the while, the opposite was observed to occur with the varying amounts of K. Unlike the Cu–Ca bond which was the least affected by the substitution, the Cu–Sr bond distance increased drastically with K substitution. All these findings indicate that Na substitution at the Ca site enhances superconductivity with no loss of interlayer interaction, while K substitution at the Sr site weakens superconductivity due to the diminished interlayer interaction.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Moara M. Castro, Shima Sabbaghianrad, Pedro Henrique R. Pereira, Eric M. Mazzer, Augusta Isaac, Terence G. Langdon, Roberto B. Figueiredo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A magnesium/aluminium composite was produced by room temperature consolidation through high-pressure torsion (HPT) processing. Half-discs of the pure metals were placed side-by-side and subjected to different numbers of turns. The initially reduced interface between the phases gradually increased with increasing rotation. The composite displayed a significant ductility even after 10 turns. The distribution of hardness in the HPT-processed discs was bi-modal in the early stages of processing. As the number of turns increased and the thickness of the phases decreased there was a noticeable increase in hardness. The hardness values of the composite further increased after thermal treatment due to the formation of intermetallics within the interface between the magnesium and aluminium-rich phases.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Lipeng Xu, Fei Zhou, Jizhou Kong, Haobin Zhou, Qian Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effects of testing temperature on the electrochemical properties of Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 are investigated in detail. When the testing temperature is 40 °C, the Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 cathode material possesses the highest initial discharge capacity of 162.4 mAh·g〈sup〉−1〈/sup〉 at 0.5C rate, but their cycling stability decreases markedly. When the test temperature rises up to 60 °C, the side reaction between electrolyte and cathode material becomes serious, and the Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 cannot work. When the testing temperature decreases, the electrochemical impedances like R〈sub〉ct〈/sub〉 values increase, and then the discharge capacity at 0 °C, −10 °C and −20 °C is only 80%, 53% and 23% of that at 25 °C. Based on the electrochemical impedance spectra at different temperatures, four kinds of equivalent circuit models are classified. The cycle and rate performance of Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 cathode material could be improved obviously through Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉(OH)〈sub〉2〈/sub〉 modification in an extreme environment, and especially in sub-zero environment.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Materials Processing Technology, Volume 273〈/p〉 〈p〉Author(s): 〈/p〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Kenji Yoshii, Naoshi Ikeda〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dielectric and magnetocaloric measurements are carried out for the chromite TmCrO〈sub〉3〈/sub〉. This oxide was reported to be multiferroic below the Néel temperature (〈em〉T〈/em〉〈sub〉N〈/sub〉) of ∼125 K, likely due to a structural transformation. The dielectric response shows large dielectric constants below 300 K. However, from the analyses of loss tangent, AC conductivity and dielectric modulus, this behavior is rooted in hopping of charge carriers rather than electric dipoles, as proposed for some other chromites. No dielectric anomaly is found at 〈em〉T〈/em〉〈sub〉N〈/sub〉. The magnetocaloric effect shows that the magnetic transitions at 〈em〉T〈/em〉〈sub〉N〈/sub〉 as well as the spin reorientation temperature are of a second order. This result strongly suggests the absence of magnetostructural transition at 〈em〉T〈/em〉〈sub〉N〈/sub〉 in accord with no observation of ferroelectric transition at this temperature.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Rattiya Hongtong, Panya Thanwisai, Rattakarn Yensano, Jeffrey Nash, Sutham Srilomsak, Nonglak Meethong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Core-shell olivine-type electrospun and doped LiFePO〈sub〉4〈/sub〉/FeS/C composite fibers were synthesized via a single-step process employing an electrospinning method using LiOH·H〈sub〉2〈/sub〉O, metal sul phates, H〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉, citric acid, and polyvinylpyrrolidone (PVP) as the starting materials. Electron microscopy studies showed that the mean diameter of the core-shell composite fibers was about 280 ± 20 nm with a LiFePO〈sub〉4〈/sub〉 phase forming a core with a diameter of about 100 ± 20 nm and a carbon shell with a thickness of 80 ± 20 nm. An FeS phase was formed by a direct reduction of iron (II) sulfate (FeSO〈sub〉4〈/sub〉) that was evenly distributed within the core region of the composite fibers and further improved the electronic conductivity of the fibers. Na〈sup〉1+〈/sup〉, Mg〈sup〉2+〈/sup〉, and Al〈sup〉3+〈/sup〉 doping ions affected fiber morphology and electrochemical performance. All composite fibers showed excellent electrochemical performance. However, Al〈sup〉3+〈/sup〉 ions improved the electrochemical performance of the composite fibers to a significantly greater degree than Na〈sup〉1+〈/sup〉 and Mg〈sup〉2+〈/sup〉 doping ions, increasing the electronic and ionic conductivities of the material while maintaining their core-shell composite fiber characteristics.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Electrospun LiFePO〈sub〉4〈/sub〉/FeS/C and 5% doped 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mi〉L〈/mi〉〈mi〉i〈/mi〉〈mi〉F〈/mi〉〈msubsup〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈mrow〉〈mn〉1〈/mn〉〈mo linebreak="badbreak"〉−〈/mo〉〈mrow〉〈mo stretchy="false"〉(〈/mo〉〈mi〉n〈/mi〉〈mi〉x〈/mi〉〈mo linebreak="badbreak"〉/〈/mo〉〈mn〉2〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈mo linebreak="badbreak"〉+〈/mo〉〈/mrow〉〈/msubsup〉〈msubsup〉〈mrow〉〈mi〉M〈/mi〉〈/mrow〉〈mrow〉〈mi〉x〈/mi〉〈/mrow〉〈mrow〉〈mi〉n〈/mi〉〈mo linebreak="badbreak"〉+〈/mo〉〈/mrow〉〈/msubsup〉〈mi〉P〈/mi〉〈msub〉〈mrow〉〈mi〉O〈/mi〉〈/mrow〉〈mrow〉〈mn〉4〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉/FeS/C (M = Na〈sup〉1+〈/sup〉, Mg〈sup〉2+〈/sup〉, Al〈sup〉3+〈/sup〉) composites with a unique core-shell structure were synthesized via a simple single-step process to improved electrochemical properties for high performance and low cost Li-ion batteries.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324946-fx1.jpg" width="287" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): L.V.B. Diop, O. Isnard〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effects of Fe substitution on the structural and magnetic properties of the HoCo〈sub〉12-〈em〉x〈/em〉〈/sub〉Fe〈sub〉〈em〉x〈/em〉〈/sub〉B〈sub〉6〈/sub〉 (0 ≤ 〈em〉x〈/em〉 ≤ 2) series of intermetallic compounds have been studied. All of the compounds form in the rhombohedral SrNi〈sub〉12〈/sub〉B〈sub〉6〈/sub〉-type structure, the lattice constants increasing linearly with 〈em〉x〈/em〉. These compounds are ferrimagnets with a small transition metal magnetic moment and exhibit a spin reorientation transition. The Curie temperature decreases from 147 K for 〈em〉x〈/em〉 = 0–105 K for 〈em〉x〈/em〉 = 2. The Fe for Co substitution leads also to a progressive decrease of the spontaneous magnetization. The spin reorientation transition temperature is significantly reduced upon Fe for Co substitution whereas the compensation temperature is much less sensitive to the Fe composition.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Acta Materialia, Volume 176〈/p〉 〈p〉Author(s): Hoheok Kim, Tatsuki Yamamoto, Yushi Sato, Junya Inoue〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We investigate the viability of establishing low-cost surrogate structure-property (S–P) linkages by introducing a Bayesian model selection method to extend the Materials Knowledge Systems (MKS) homogenization framework, which employs the n-point spatial correlation function, principal component analysis, and regression techniques. In particular, we place emphasis not only on choosing the important structural features but also on interpreting their implications for the property under consideration. First, the yield strengths of synthetic microstructures with various morphological characteristics are estimated by physics-based crystal plasticity simulation. Then, the dimension-reduced microstructural features are revealed by a combination of 2-point spatial correlations and principal component analysis. The Bayesian model selection method is further applied to establish a microstructure-to-yield-strength surrogate model. Finally, the model is validated with an independent dataset and its constituent features are interpreted with a morphology reconstruction based on a Monte Carlo algorithm. The method is found to be capable of interpreting the key microstructural features as well as modeling the mechanical response of a dual-phase metallic composite in consideration of the diverse microstructural factors.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1359645419304367-fx1.jpg" width="274" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Maxim S. Likhanov, Vladislav O. Zhupanov, Valeriy Yu Verchenko, Andrei A. Gippius, Sergei V. Zhurenko, Alexey V. Tkachev, Dina I. Fazlizhanova, David Berthebaud, Andrei V. Shevelkov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a new Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 solid solution, in which a 5〈em〉d〈/em〉-metal––rhenium––partially substitutes for iron to the limiting composition of 〈em〉x〈/em〉 = 0.10. The crystal structure refined for the composition Fe〈sub〉0.91〈/sub〉Re〈sub〉0.09〈/sub〉Ga〈sub〉3〈/sub〉 shows the expected increase in the unit cell parameters compared to the parent FeGa〈sub〉3〈/sub〉 compound, however the M–M (M = Fe, Re) distance decreases within the M–M dumbbell, indicating an increased M–M bonding density. Therein, investigation of the local structure by means of 〈sup〉69,71〈/sup〉Ga NQR spectroscopy revealed the formation of homonuclear Fe–Fe and Re–Re dumbbells. Transport and thermoelectric properties have been investigated for the Re-substituted FeGa〈sub〉3〈/sub〉. Electrical transport measurements showed preservation of the nonmetallic conductivity of Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 despite the decrease of the valence electron concentration from 17 to 16.9 electrons per formula. At low temperatures, Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 is a 〈em〉p〈/em〉-type semiconductor with the band gap of 0.4 eV, but with increasing temperature the sign of the dominant charge carriers changes. Owing to the alloying effect, Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 displays 1.5 times lower thermal conductivity than FeGa〈sub〉3〈/sub〉, which increases at high temperatures because of the growing contribution of the electronic term.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819325198-fx1.jpg" width="454" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biomass and Bioenergy, Volume 127〈/p〉 〈p〉Author(s): Shuping Zhang, Shuguang Zhu, Houlei Zhang, Xinzhi Liu, Huiyan Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effect of combined pretreatment on the mechanism of pyrolysis behavior and pyrolysis products (bio-oil, non-condensable gas and char) of rice husk was investigated using thermogravimetric analyzer (TGA) and laboratory-scale fixed-bed reactor. A coupling method combining iso-conversional method and model-fitting method was used to obtain the pyrolysis kinetic parameter. Pyrolysis kinetics results indicated that activation energy (〈em〉E〈/em〉) gradually increased with the increase of conversion rate (〈em〉α〈/em〉), which was due to the differences in thermal stability of biomass components. Acid washing pretreatment slightly increased the average activation energy (〈em〉E〈/em〉〈sub〉a〈/sub〉), and then subsequent torrefaction process further increased it. The entire pyrolysis reaction process of all the rice husk samples can be described by the reaction-order model. In addition, a laboratory-scale fixed-bed reactor was used to investigate the yields and detailed characteristics of pyrolysis products. The results suggested that phenols and sugars contents in bio-oil increased, while that of small-molecule components with high thermal instability decreased, which was favor for the storage and subsequent utilization of bio-oil. Rice husk char obtained from pyrolysis also has the potential for preparation of silica products. We concluded that combined pretreatment of washing and torrefaction significantly improved the thermochemical utilization potential of rice husk for fuels and chemicals by pyrolysis.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0961953419302429-fx1.jpg" width="307" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Jiashu Zhang, Weiyao Zhao, Zhenjie Feng, Jun-Yi Ge, Jincang Zhang, Shixun Cao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the crystal growth, structure analysis and magnetic phase transitions in the single crystal Sm〈sub〉0.15〈/sub〉Dy〈sub〉0.85〈/sub〉FeO〈sub〉3〈/sub〉. The high-quality of the crystal is verified by X-ray diffraction technique. Our research reveals that: 1) the iron sublattice spin reorientation (SR) transition emerges at 25 K, and ends at 10 K; 2) the rare earth antiferromagnetic (AF) order transition happens at 2.6 K; 3) there is a special wasp-waist hysteresis loop at low temperatures. Knowledge of such phase transitions in rare earth orthoferrite system is of potential importance for applications and theoretical studies.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 253〈/p〉 〈p〉Author(s): Ji Soo Yu, Sung Hun Kim, Minh Tan Man, Hong Seok Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have successfully demonstrated the colloidal hot-injection process to easily obtain the Mn-doped ZnSe quantum dots (QDs) with a size of about 4–5 nm, and 〈em〉d〈/em〉-spacing is 0.31 nm, corresponding to the (1 1 1) lattice plane of ZnSe. Experimental results show that UV–vis absorption and fluorescence spectra were recorded to elucidate the role of Mn〈sup〉2+〈/sup〉 ions substituted into ZnSe, which resulted in the carrier transfer of luminescent sites by a small amount of Mn〈sup〉2+〈/sup〉 dopant. The small size of the Mn-doped ZnSe QDs offers intriguing opportunities for their application in photonic, bioimaging, and spintronics devices.〈/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-S0167577X19309905-ga1.jpg" width="298" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 254〈/p〉 〈p〉Author(s): Mohamad Fahrul Radzi Hanifah, Juhana Jaafar, M.H.D. Othman, A.F. Ismail, M.A. Rahman, Norhaniza Yusof, Farhana Aziz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanocluster-like Pt nanoparticles/reduced graphene oxide nanocomposite catalyst (NC-PtNPs/RGO) was synthesized through a novel one-step process of chemical reduction-assisted hydrothermal reaction by using formic acid as reducing agent. The crystallinity, morphology and composition of the NC-PtNPs/RGO catalysts were extensively characterized. The as-prepared NC-PtNPs/RGO catalysts exhibited higher electro-catalytic activity towards methanol oxidation than carbon black (CB)/PtNPs catalyst and could be ascribed to the high dispersion of NC-Pt NPs with large electrochemical surface area, release more exposure of active sites by NC-PtNPs structure and synergy effect of RGO.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 253〈/p〉 〈p〉Author(s): Zhenhua Wang, Yi Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Σ3 boundaries improve the intergranular corrosion resistance of high nitrogen austenitic stainless steels. However, the regeneration of these boundaries is, unfortunately, accompanied by significant grain coarsening. 18Mn18Cr0.5N and 18Mn18Cr0.6N steels were thermo-mechanically processed and the corresponding microstructures were evaluated. Formation mechanisms were proposed for Σ1 boundaries in different R-Σ3-Σ1-type junctions. These boundaries formed during grain growth accompanying Σ3 formation and reaction. After 30% cold tension and cyclic heating between 500 °C and 1100 °C, numerous Σ1 boundaries were formed and disrupted the high angle grain boundary network efficiently. Moreover, a small grain size was maintained. Σ1 boundaries have significant application potential in grain boundary engineering.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 254〈/p〉 〈p〉Author(s): Rui Wang, Dongdong Gu, Lixia Xi, Kaijie Lin, Meng Guo, Hongmei Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Selective laser melting (SLM), as a rapidly developed layer-by-layer 3D printing technology, has been demonstrated that it can be used for additive manufacturing of multi-materials. In this work, TiB〈sub〉2〈/sub〉/Ti6Al4V multi-materials were manufactured by SLM. The results showed that interfacial microstructures consisting of un-melted TiB〈sub〉2〈/sub〉 powders, columnar TiB crystals, and acicular TiB crystals were formed in the molten pool. Meanwhile, a variation nanohardness was developed with chemical compositions at the interfacial regions, owing to an in-situ reaction of Ti and TiB〈sub〉2〈/sub〉. The first-principle calculations were used to reveal the axial growth of TiB crystals as well as the different hardness of this system.〈/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-S0167577X19310006-ga1.jpg" width="346" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 253〈/p〉 〈p〉Author(s): Siyao Xie, Ruidi Li, Linjun Tang, Tiechui Yuan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The diffusion behavior of Al in FeCoCrNiMo〈sub〉x〈/sub〉 high-entropy alloys (HEAs) at temperatures ranging from 773 to 873 K with and without pulse current was studied in this paper. The diffusion coefficients 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mi〉D〈/mi〉〈/math〉 was determined based on the Fick’s law and corresponding pre-exponential factor 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"〉〈msub〉〈mi〉D〈/mi〉〈mn〉0〈/mn〉〈/msub〉〈/math〉, as well as activation energy 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"〉〈msub〉〈mi〉Q〈/mi〉〈mi〉D〈/mi〉〈/msub〉〈/math〉. It was found that the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mi〉D〈/mi〉〈/math〉 under pulse current dramatically increased about hundreds of times in contrast with that without current. In addition, the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"〉〈msub〉〈mi〉D〈/mi〉〈mn〉0〈/mn〉〈/msub〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"〉〈msub〉〈mi〉Q〈/mi〉〈mi〉D〈/mi〉〈/msub〉〈/math〉 were determined to reduce from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.svg"〉〈mrow〉〈msubsup〉〈mrow〉〈mn〉1.369〈/mn〉〈/mrow〉〈mrow〉〈mo〉-〈/mo〉〈mn〉0.324〈/mn〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈mn〉0.424〈/mn〉〈/mrow〉〈/msubsup〉〈mo〉×〈/mo〉〈msup〉〈mrow〉〈mn〉10〈/mn〉〈/mrow〉〈mrow〉〈mo〉-〈/mo〉〈mn〉13〈/mn〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉 to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si17.svg"〉〈mrow〉〈msubsup〉〈mrow〉〈mn〉5.016〈/mn〉〈/mrow〉〈mrow〉〈mo〉-〈/mo〉〈mn〉1.984〈/mn〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈mn〉3.284〈/mn〉〈/mrow〉〈/msubsup〉〈mo〉×〈/mo〉〈msup〉〈mrow〉〈mn〉10〈/mn〉〈/mrow〉〈mrow〉〈mo〉-〈/mo〉〈mn〉15〈/mn〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉 m〈sup〉2〈/sup〉/s, and from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si6.svg"〉〈mrow〉〈mn〉39.7〈/mn〉〈mo〉±〈/mo〉〈mn〉1.8〈/mn〉〈/mrow〉〈/math〉 to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si18.svg"〉〈mrow〉〈mn〉21.6〈/mn〉〈mo〉±〈/mo〉〈mn〉3.4〈/mn〉〈/mrow〉〈/math〉 kJ/mol respectively with the Mo contents increasing from Mo〈sub〉0〈/sub〉 to Mo〈sub〉0.2〈/sub〉 without pulse current. The introduction of pulse current into the diffusion couples dramatically promoted the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"〉〈msub〉〈mi〉D〈/mi〉〈mn〉0〈/mn〉〈/msub〉〈/math〉 at all the diffusion couples. However, the pulse current was ascertained to obviously increase the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"〉〈msub〉〈mi〉Q〈/mi〉〈mi〉D〈/mi〉〈/msub〉〈/math〉 in contrast to that of diffusion couples without pulse current.〈/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-S0167577X19309899-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Yuliang Jiang, Xueyan Fu, Zidong Zhang, Wei Du, Peitao Xie, Chuanbing Cheng, Runhua Fan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Carbon nanofibers embedded with magnetic Fe〈sub〉3〈/sub〉C nanoparticles have been synthesized using electrospinning technique, followed by one-step carbonization. By using Fe〈sub〉3〈/sub〉C/C nanofibers as filler with 10% content, the sample can achieve a minimum reflection loss (RL) of −54.94 dB with a thickness of 1.36 mm, as well as the broad effective absorption bandwidth (EAB) can reach to 4.5 GHz (13.3–17.8 GHz) at the thickness of 1.55 mm. The superior properties might be due to the synergistic effects of dielectric loss, magnetic loss, multiple scattering and reflection. This work presents a facile and promising method to produce high performance microwave absorption materials with thin thickness, light weight and strong absorption.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): E.J. Pickering, K.A. Christofidou, H.J. Stone, N.G. Jones〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to reduce the environmental impact of air travel, it is desirable that the efficiencies of gas turbine engines are increased. One way to achieve this goal is to increase the operating temperatures of the engine cores. Unfortunately for aero-engine manufacturers, the temperature capability limits of the Ni-base superalloys used currently have been reached. Hence, new alloys need to be developed that are capable of operating at significantly higher temperatures. In this article, the potential of tantalum-base superalloys is discussed and explored. A suite of alloys based on the Ta-Al-Co system was investigated. It was found that an array of fine carbide precipitates was formed in the Ta-rich matrix in a subset of the alloys, which is promising in terms of developing a strong and damage-tolerant microstructure, but that the elemental partitioning of Al out of the matrix accompanying precipitation is likely to degrade environmental resistance. Nevertheless, it is believed that the design principles described have the potential to facilitate the development of the next generation of high-temperature alloys based on systems of this type.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): C.Q. Zhou, Q.A. Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to understand the effect of Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 nanoparticles on crystallite growth kinetics of nanocrystalline Mg, the crystallite growth characteristics in a Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite and a pure Mg sample were comparatively investigated in this work. The crystallite growth exponents of nanocrystalline Mg in the Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite and pure Mg were determined as 〈em〉n〈/em〉 = 5 and 〈em〉n〈/em〉 = 4, respectively. Meanwhile, the activation energy for crystallite growth in Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite was calculated to be 118.8 kJ/mol, which is higher than 97.1 kJ/mol in pure nanocrystalline Mg. Further studies reveal that the rise of crystallite growth exponent and increase of activation energy in the Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite are primarily attributed to the pinning effect of Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 nanoparticles at crystallite boundaries of Mg.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Liming Tan, Yunping Li, Wenkai Deng, Yong Liu, Feng Liu, Yan Nie, Liang Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three Ni-base powder metallurgy superalloys have been developed recently, and tensile tests at temperatures ranging from room temperature (RT) to 815 °C were conducted on them. The results conformed their excellent tensile properties, in comparison with several other existed polycrystalline superalloys. In this work, by means of microstructure characterization, thermal dynamic calculations, and theoretical modeling, different strengthening mechanisms including precipitation strengthening, grain boundary strengthening, solid solution strengthening, and Orowan strengthening, were found to contribute to the yield strength in different degrees, which would help to further enhance the tensile properties of these alloys through composition design and processing optimization thereafter.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324892-fx1.jpg" width="459" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Acta Materialia, Volume 176〈/p〉 〈p〉Author(s): Denise C. Ford, David Hicks, Corey Oses, Cormac Toher, Stefano Curtarolo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Metallic glasses are excellent candidates for biomedical implant applications due to their inherent strength and corrosion resistance. However, use of metallic glasses in structural applications is limited because bulk dimensions are challenging to achieve. Glass-forming ability (GFA) varies strongly with alloy composition and becomes more difficult to predict as the number of chemical species in a system increases. Here, we present a theoretical model — implemented in the AFLOW framework — for predicting GFA based on the competition between crystalline phases. The model is applied to biologically relevant binary and ternary systems. Elastic properties of Ca- and Mg-based systems are estimated for use in biodegradable orthopedic support applications. Alloys based on Ag〈sub〉0.33〈/sub〉Mg〈sub〉0.67〈/sub〉, Cu〈sub〉0.5〈/sub〉Mg〈sub〉0.5〈/sub〉, Cu〈sub〉0.37〈/sub〉Mg〈sub〉0.63〈/sub〉, and Cu〈sub〉0.25〈/sub〉Mg〈sub〉0.5〈/sub〉Zn〈sub〉0.25〈/sub〉, and in the Ag-Ca-Mg and Ag-Mg-Zn systems, are recommended for further study.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1359645419304380-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Letters, Volume 254〈/p〉 〈p〉Author(s): C.Q. Zhang, W. Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Al〈sub〉3〈/sub〉Ti intermetallic compound (IMC) layer growth kinetics at Al-Ti interface was investigated. Surprisingly an abnormal effect of temperature was observed with a thicker IMC layer formed at lower annealing temperature due to the much faster Al〈sub〉3〈/sub〉Ti grain coarsening at a higher temperature, the IMC layer growth at 630 °C became slower than that at 600 °C after a certain annealing time. The quantitative influence of grain size on effective diffusion coefficient was analysed. Calculations showed that the lattice diffusion makes little contribution to the effective diffusion coefficient. Grain boundary diffusion, therefore, dominates for all the annealing conditions studied.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: July–August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Materials Today, Volume 27〈/p〉 〈p〉Author(s): David Bradley〈/p〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Scripta Materialia, Volume 171〈/p〉 〈p〉Author(s): Guang Wang, Xiannian Sun, Jinhai Xu, Yingchun Shan, Xiaoguang Han, Jiujun Xu, Jiangtao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two transparent AlON ceramics substrates were successfully pressureless joined at 1880 °C for 80 min by using a powder interlayer of parent material. The grains on the interface of the joint were simultaneously shared by both interlayer and substrates due to grain growth and coalescence, which can evidently be categorized as thermal diffusion bonding under pressureless condition. The identical phase assemblage and microstructure for both interlayer and substrates lead to a bending strength of the joint (229.1 MPa) nearly equal to that of substrates, which is much higher than that of the reported AlON joints.〈/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-S1359646219303835-ga1.jpg" width="242" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 26 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 36〈/p〉 〈p〉Author(s): Zhiguo Liu, Xiao Zhang, Zhixiang Jiang, Hsueh-Shih Chen, Ping Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Non-metal doping not only optimizes the energy band structure of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 to improve the absorption of visible light, but also exacerbates the distortion of lowest and highest unoccupied molecular orbital plane, causing polarization, thereby improving photocatalytic activity. For the first time, S and P are co-introduced into g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 network to enhance photocatalytic performance and create various tubular morphologies. The ratio of S to P is crucial to control the tubular morphology and property. In the photocatalytic process, the separation of electrons and holes causes by the polarization of the S and P elements and the synergy of the tubular morphology results in new migration paths for photogenerated electrons and holes. Using optimized preparation conditions, g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 tubes co-doped with S and P (CNSP) reveal very high H〈sub〉2〈/sub〉 generation efficiency (163.27 μmol/h), which is two orders of magnitude higher compared to that of pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and apparent quantum yield is 18.93% at 420 nm. Fast degradation of Rhodamine B by using CNSP occurs within 5 min under visible light irradiation. Because of the reproducible process, the synthetic strategy provides a novel method for controlling the morphology of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉-based materials with super activity.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0360319919322487-fx1.jpg" width="311" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Shuguo Qu, Minhui Li, Chenchen Zhang, Jihai Duan, Weiwen Wang, Jianlong Li, Xiaojin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel proton exchange membrane was synthesized by embedding a crystalline which was nano-assembled through trimesic acid and melamine (TMA·M) into the matrix of the sulfonated poly (ether ether ketone) (SPEEK) to enhance the proton conductivity of the SPEEK membrane. Fourier transform infrared indicated that hydrogen bonds existed between SPEEK and TMA·M. XRD and SEM indicated that TMA·M was uniformly distributed within the matrix of SPEEK, and no phase separation occurred. Thermogravimetric analysis showed that this membrane could be applied as high temperature proton exchange membrane until 250 °C. The dimensional stability and mechanical properties of the composite membranes showed that the performance of the composite membranes is superior to that of the pristine SPEEK. Since TMA·M had a highly ordered nanostructure, and contained lots of hydrogen bonds and water molecules, the proton conductivity of the SPEEK/TMA·M-20% reached 0.00513 S cm〈sup〉−1〈/sup〉 at 25 °C and relative humidity 100%, which was 3 times more than the pristine SPEEK membrane, and achieved 0.00994 S cm〈sup〉−1〈/sup〉 at 120 °C.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Ying Han, Weirong Chen, Qi Li, Hanqing Yang, Firuz Zare, Yongkang Zheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the fast development of DC Microgrid (MG) technology, its operating economy and reliability are getting more and more concern. The traditional distributed control method is aimed at power balance and system stability, and is difficult to meet the requirement of energy management system for multi-source hybrid DC MG. This paper provides a two-level energy management strategy for PV-fuel cell-battery-based DC MG, which is divided into device control level and system control level. At the device control level, the distributed control methods based on MPPT-droop dual-mode control and droop control are proposed to enhance system reliability; at the system control level, the equivalent consumption minimization strategy (ECMS) is used to distribute system net power between battery pack and fuel cell system. A lab-scale DC microgrid platform is developed to verify the proposed energy management strategy in this paper. Moreover, the analysis and compare of the results show that the proposed two-level energy management strategy can achieve lower equivalent hydrogen consumption than classical PI control and state machine control method.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Nicolás Cobos Ullvius, Masoud Rokni〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉While energy demand in this fast developing world is increasing, its future is being compromised by the CO〈sub〉2〈/sub〉 emissions produced through the burning of fossil fuels. Clean energy technologies are available, but there are still barriers hindering their full integration into the society, the majority of which are economic and social. For these reasons, the development of new technologies and configurations to make renewable energies systems more cost-effective is urgently needed. The plant design proposed in this paper consists of basic Dish-Stirling collectors supported by a reversible solid oxide fuel cell acting as a power generator and storage unit, and therefore offering dispatchable power on demand. Further, the system reuses the waste heat for seawater desalination, which is very convenient for arid areas with high solar radiation and shortage of freshwater. The present work is an analytical study in which thermodynamic investigation of the performance evaluation of a self-sustainable polygeneration system with integrated hydrogen production, power generation, and freshwater production is conducted. An evaluation in a real context (South Africa) showed the potential of this system to supply 500 kW, 24 h a day, while producing a considerable amount of freshwater. Although the distillation system presented is able to produce 8464 L per day, there is potential for it to increase its output by nine times or more.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Hongri Wan, Xiaofang Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nitrogen/sulfur co-doped disordered porous biocarbon was facilely synthesized and applied as anode materials for lithium/sodium ion batteries. Benefiting from high nitrogen (3.38 wt%) and sulfur (9.75 wt%) doping, NS〈sub〉1-1〈/sub〉 as anode materials showed a high reversible capacity of 1010.4 mA h g〈sup〉−1〈/sup〉 at 0.1 A g〈sup〉−1〈/sup〉 in lithium ion batteries. In addition, it also exhibited excellent cycling stability, which can maintain at 412 mAh g〈sup〉-1〈/sup〉 after 1000 cycles at 5 A g〈sup〉−1〈/sup〉. As anode materials of sodium ion batteries, NS〈sub〉1-1〈/sub〉 can still reach 745.2 mA h g〈sup〉−1〈/sup〉 at 100 mAg〈sup〉-1〈/sup〉 after 100 cycles. At a high current density (5 A g〈sup〉-1〈/sup〉), the reversible capacity is 272.5 mA h g〈sup〉−1〈/sup〉 after 1000 cycles, which exhibits excellent electrochemical performance and cycle stability. The preeminent electrochemical performance can be attributed to three effects: (1) the high level of sulfur and nitrogen; (2) the synergic effect of dual-doping heteroatoms; (3) the large quantity of edge defects and abundant micropores and mesopores, providing extra Li/Na storage regions. This disordered porous biocarbon co-doped with nitrogen/sulfur exhibits unique features, which is very suitable for anode materials of lithium/sodium ion batteries.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0360319919323572-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Zhilong Wei, Haisheng Zhen, Jin Fu, Chunwah Leung, Chunshun Cheung, Zuohua Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The laminar burning velocities of biogas-hydrogen-air mixture at different fuel compositions and equivalence ratios were determined and studied using the spherical flame method. The combined effects of H〈sub〉2〈/sub〉 and CO〈sub〉2〈/sub〉 on the laminar burning velocity were investigated quantitatively based on the kinetic effects and the thermal effects. The results show that the laminar burning velocities of the BG40, BG50 and BG60 are increased almost linearly with the H〈sub〉2〈/sub〉 addition owing to the improved fuel kinetics and the increased adiabatic flame temperature. The dropping trend of laminar burning velocity from the BG60-hydrogen to the BG40-hydrogen is primarily attributed to the decreased adiabatic flame temperature (thermal effects). The GRI 3.0 mechanism can predict the laminar burning velocity of biogas-hydrogen mixture better than the San Diego mechanism in this study. Whereas, the GRI mechanism still needs to be modified properly for the hydrogen-enriched biogas as the CO〈sub〉2〈/sub〉 proportion exceeds 50% in the biogas at the fuel-rich condition. The increased CO〈sub〉2〈/sub〉 exerts the stronger suppression on the net reaction rate of H + O〈sub〉2〈/sub〉=OH + O than that of H + CH〈sub〉3〈/sub〉(+M) = CH〈sub〉4〈/sub〉(+M), which contributes to that the rich-shift of peak laminar burning velocity of biogas-hydrogen mixture requires higher H〈sub〉2〈/sub〉 addition as the CO〈sub〉2〈/sub〉 content is enhanced. For the biogas-hydrogen fuel, the H〈sub〉2〈/sub〉 addition decreases the flame stability of biogas fuel effectively due to the increased diffusive-thermal instability and hydrodynamic instability. The improved flame stability of biogas-hydrogen fuel with the increased CO〈sub〉2〈/sub〉 content is resulted from the combined effects of diffusive-thermal instability and hydrodynamic instability.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Guorui Zhang, Qi Li, Weirong Chen, Xiang Meng, Huiwen Deng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to improve the robustness of the energy management system (EMS) and avoid the influence of demand power on the design of EMS, a coupled power-voltage equilibrium strategy based on droop control (CPVE-DC) is proposed in this paper. Making use of the principal that the DC bus can directly reflect the changes of load power, the proposed strategy couples DC bus voltage with output powers through droop control to achieve self-equilibrium. The proposed EMS is applied into a hybrid tramway model configured with multiple proton exchange membrane fuel cell (PEMFC) systems, batteries and super capacitors (SCs). FC systems and SC systems are responsible for satisfying most of the demand power, therefore the CPVE-DC strategy generates FCs and SCs reference power through power-voltage droop control on the primary control. Then batteries supplement the rest part of load power and generate DC bus voltage reference value of the next sampling time. With the gambling between output power and DC bus voltage, the hybrid system achieves self-equilibrium and steps into steady operation by selecting appropriate droop coefficients. Then the secondary control of the proposed strategy allocates power between every single unit. In addition, a penalty coefficient is introduced to balance SOC of SCs. The proposed strategy is tested under a real drive cycle LF-LRV on RT-LAB platform. The results demonstrate that the proposed strategy can achieve self-equilibrium and is effective to allocate demand power among these power sources，achieve active control for the range of DC bus voltage and SOC consensus of SCs as well. In addition, some faults are simulated to verify the robustness of the proposed strategy and it turns out that the CPVE-DC strategy possesses higher robustness. Finally, the CPVE-DC strategy is compared with equivalent consumption minimization strategy (ECMS) and the results shows that the proposed strategy is able to get higher average efficiency and lower equivalent fuel consumption.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 26 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 36〈/p〉 〈p〉Author(s): Alexander N. Bondarchuk, Iván Corrales-Mendoza, Sergio A. Tomás, Frank Marken〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photoelectrochemical water splitting using solar energy is a highly promising technology to produce hydrogen as an environmentally friendly and renewable fuel with high-energy density. This approach requires the development of appropriate photoelectrode materials and substrates, which are low-cost and applicable for the fabrication of large area electrodes. In this work, hematite photoelectrodes are grown by aerosol assisted chemical vapour deposition (AA-CVD) onto highly-conductive and bulk porous SnO〈sub〉2〈/sub〉 (Sb-doped) ceramic substrates. For such photoelectrodes, the photocurrent density of 2.8 mA cm〈sup〉-2〈/sup〉 is achieved in aqueous 0.1 M NaOH under blue LED illumination (〈em〉λ〈/em〉 = 455 nm; 198 mW cm〈sup〉-2〈/sup〉) at 1.23 V vs. RHE (reversible hydrogen electrode). This relatively good photoelectrochemical performance of the photoelectrode is achieved despite the simple fabrication process. Good performance is suggested to be related to the three-dimensional morphology of the porous ceramic substrate resulting in excellent light-driven charge carrier harvesting. The porosity of the ceramic substrate allows growth of the photoactive layer (SnO〈sub〉2〈/sub〉-grains covered by hematite) to a depth of some micrometers, whereas the thickness of Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-coating on individual grains is only about 100–150 nm. This architecture of the photoactive layer assures a good light absorption and it creates favourable conditions for charge separation and transport.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): J. Büsselmann, M. Rastedt, V. Tullius, K. Yezerska, A. Dyck, P. Wagner〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the help of consistent conditions for improved batch production and defined quality standards, the lifetime of fuel cell systems should be improved and cost-intensive losses should be minimized at an early state in the production process. Within this work, we concentrated on two accelerated stress tests: load cycling at high current densities and start/stop cycling to compare high temperature (HT) polymer electrolyte membrane (PEM) membrane electrode assemblies (MEAs) of three suppliers to evaluate performances and degradation rates under such conditions. These MEAs have been investigated in-situ via electrochemical characterization. MEAs of three providers differ significantly in their performance and power output for both operation strategies. It was also shown that load cyclization causes greater stress on the MEA than start/stop cycling. Next to the manufacturer comparison, a batch-to-batch evaluation of one provider has been performed including micro-computed tomography (μ-CT) investigations and the determination of the tortuosity of the cathode side gas diffusion layers.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Gisela Orcajo, Helena Montes-Andrés, José A. Villajos, Carmen Martos, Juan A. Botas, Guillermo Calleja〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The organometallic Li-Crown ether species, formed by the complexation of lithium cation with the hydrophobic 18Crown6 ether, has been included in three Metal-Organic-Framework〈del〉s〈/del〉 (MOF) structures with different pore size: Cr-MIL-101, Fe-MIL100 and Ni-MOF-74. X-ray powder diffraction, thermogravimetric analysis, proton nuclear magnetic resonance, infrared spectroscopy and inductively coupled plasma atomic emission spectroscopy measurements have proved the successful incorporation of the organometallic units to the three MOFs without altering their crystalline structure. Hydrogen adsorption properties of the post-synthesis modified materials have been evaluated in a wide temperature (77–298 K) and pressure (1–170 bar) range conditions. The post-synthetic modification method used based on the MOF impregnation with a Li-Crown ether complex solution produced a partial pore blocking effect on the microporous Ni-MOF-74, reducing its hydrogen adsorption capacity. However, the inclusion of the crown-ether and particularly the Li-Crown ether complex resulted in an increase of the volumetric hydrogen adsorption capacity at room temperature for Cr-MIL101 and Fe-MIL-100, due to the pore volume reduction, higher confinement of H〈sub〉2〈/sub〉 molecules in the cavities and the formation of new specific binding sites for H〈sub〉2〈/sub〉 molecules. The inclusion of Li-Crown ether complex also enhances the H〈sub〉2〈/sub〉 interaction with the mesoporous MOF structures, attributed to the additional electrostatic interactions produced by the presence of Li〈sup〉+〈/sup〉 ions complexed to the crown ether molecules. Further work following this strategy to improve hydrogen adsorption capacity of mesoporous MOFs at room temperature should be extended to other MOF materials, checking its influence on their capacity for gas separation purposes.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Quentin Bellouard, Sylvain Rodat, Stéphane Abanades, Serge Ravel, Pierre-Éric Frayssines〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The use of concentrated solar energy as the high-temperature heat source for the thermochemical gasification of biomass is a promising prospect for producing CO〈sub〉2〈/sub〉-neutral chemical fuels (syngas). The solar process saves biomass resource because partial combustion of the feedstock is avoided, it increases the energy conversion efficiency because the calorific value of the feedstock is upgraded by the solar power input, and it also reduces the need for downstream gas cleaning and separation because the gas products are not contaminated by combustion by-products. A new concept of solar spouted bed reactor with continuous biomass injection was designed in order to enhance heat transfer in the reactor, to improve the gasification rates and gas yields by providing constant stirring of the particles, and to enable continuous operation. Thermal simulations of the prototype were performed to calculate temperature distributions and validate the reactor design at 1.5 kW scale. The reliable operation of the solar reactor based on this new design was also experimentally demonstrated under real solar irradiation using a parabolic dish concentrator. Wood particles were continuously gasified at temperatures ranging from 1100 °C to 1300 °C using either CO〈sub〉2〈/sub〉 or steam as oxidizing agent. Carbon conversion rates over 94% and gas productions over 70 mmol/g〈sub〉biomass〈/sub〉 were achieved. The energy contained in the biomass was upgraded thanks to the solar energy input by a factor of up to 1.21.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S036031991831334X-fx1.jpg" width="244" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Antonio Valente, Diego Iribarren, Javier Dufour〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The environmental sustainability of hydrogen energy systems is often evaluated through Life Cycle Assessment (LCA). In particular, environmental suitability is usually determined by comparing the life-cycle indicators calculated for a specific hydrogen energy system with those of a reference system (e.g., conventional hydrogen from steam methane reforming, SMR-H〈sub〉2〈/sub〉). In this respect, harmonisation protocols for comparative LCA of hydrogen energy systems have recently been developed in order to avoid misleading conclusions in terms of carbon footprints and cumulative energy demand. This article expands the scope of these harmonisation initiatives by addressing a new life-cycle indicator: acidification. A robust protocol for harmonising the acidification potential of hydrogen energy systems is developed and applied to both SMR-H〈sub〉2〈/sub〉 and a sample of case studies of renewable hydrogen. According to the results, unlike other energy systems, there is no correlation between acidification and carbon footprint in the case of hydrogen energy systems, which prevents the estimation of harmonised acidification results from available harmonised carbon footprints. Nevertheless, an initial library of harmonised life-cycle indicators of renewable hydrogen is now made available.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Paul Brack, S.E. Dann, K.G.U. Wijayantha, Paul Adcock, Simon Foster〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ferrosilicon 75, a 50:50 mixture of silicon and iron disilicide, has been activated toward hydrogen generation by processing using ball milling, allowing a much lower concentration of sodium hydroxide (2 wt %) to be used to generate hydrogen from the silicon in ferrosilicon with a shorter induction time than has been reported previously. An activation energy of 62 kJ/mol was determined for the reaction of ball-milled ferrosilicon powder with sodium hydroxide solution, which is around 30 kJ/mol lower than that previously reported for unmilled ferrosilicon. A series of composite powders were also prepared by ball milling ferrosilicon with various additives in order to improve the hydrogen generation properties from ferrosilicon 75 and attempt to activate the silicon in the passivating FeSi〈sub〉2〈/sub〉 component. Three different classes of additives were employed: salts, polymers and sugars. The effects of these additives on hydrogen generation from the reaction of ferrosilicon with 2 wt% aqueous sodium hydroxide were investigated. It was found that composites formed of ferrosilicon and sodium chloride, potassium chloride, sodium polyacrylate, sodium polystyrene sulfonate-co-maleic acid or fructose showed reduced induction times for hydrogen generation compared to that observed for ferrosilicon alone, and all but fructose also led to an increase in the maximum hydrogen generation rate. In light of its low cost and toxicity and beneficial effects, sodium chloride is considered to be the most effective of these additives for activating the silicon in ferrosilicon toward hydrogen generation. Materials characterisation showed that neither ball milling on its own nor use of additives was successful in activating the FeSi〈sub〉2〈/sub〉 component of ferrosilicon for hydrogen generation and the improvement in rate and shortening of the induction period was attributed to the silicon component of the mixture alone The gravimetric storage capacity for hydrogen in ferrosilicon 75 is therefore maintained at only 3.5% rather than the 10.5% ideally expected for a material containing 75% silicon. In light of these results, ferrosilicon 75 does not appear a good candidate for hydrogen production in portable applications.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Ioan Iordache, Karel Bouzek, Martin Paidar, Karin Stehlík, Johannes Töpler, Mirosław Stygar, Juliusz Dąbrowa, Tomasz Brylewski, Ioan Stefanescu, Mihaela Iordache, Dorin Schitea, Sergey A. Grigoriev, Vladimir N. Fateev, Viacheslav Zgonnik〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The article contains examples about hydrogen research and development progress in different countries: Czech Republic, Poland, Romania, Russia and Ukraine. Each chapter describes a specific situation for a country and one of them describes some aspects from Germany for comparison with one of international leaders. The examples described into articles are not aleatory. The intention of the authors is to give to the reader the possibility to understand the concrete examples about what means the state of hydrogen and fuel cell research and innovation in the Central and Eastern European countries. The chapters dedicated to Czech Republic, Poland, and Romania, reveal the commitment of these countries in this adventure, often viewed today as a subject of very advanced countries. The specific situation in the Russia Federation describes a strong background, an uncertain present and a questionable future for the hydrogen and fuel cell technology. Development of hydrogen technologies and fuel cells in Ukraine have a long history, also. All of that, in the EU context, by voice of the main stakeholders, considered the hydrogen and fuel cell a decisive issue, with economic and societal ramifications.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Evangelos I. Gkanas, Thomas Statheros, Martin Khzouz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A numerical study fully validated with solid experimental results is presented and analysed, regarding the hydrogenation process of rectangular metal hydride tanks for green building applications. Based on a previous study conducted by the authors, where the effective heat management of rectangular tanks by using plain embedded cooling tubes was analysed, in the current work the importance of using extended surfaces to enhance the thermal properties and the hydrogenation kinetics is analysed. The studied extended surfaces (fins) were of rectangular shape; and several combinations regarding the number of fins and the fin thickness were examined and analysed. The values for fin thickness were 2-3-5 and 8 mm and the number of fins studied were 10-14-18 and 20. To evaluate the effect of the heat management process, a modified version of a variable named as Non-Dimensional Conductance (NDC) is introduced and studied. A novel AB〈sub〉2〈/sub〉-Laves phase intermetallic was considered as the metal hydride for the study. The results of the hydrogenation behaviour for the introduced parameters (fin number and thickness) showed that the rectangular tank equipped with the cooling tubes in combination with 14 fins of 5 mm fin thickness has the capability of storing hydrogen over 90% of its theoretical capacity in less than 30 min.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 4 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Zhao-Hui Ruan, Yu-Dong Li, Yuan Yuan, Kai-Feng Lin, He-Ping Tan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As is reported, the photocatalytic activity will increase significantly when TiO〈sub〉2〈/sub〉 nanoparticles are agglomerated into TiO〈sub〉2〈/sub〉 nanofibers (NFs), but the photocatalytic activity enhancement mechanisms are still not fully understood. As is widely accepted, the optical absorption process plays a key role in photocatalysis, and it can even be said that the optical absorption capability of the photocatalyst directly determines its photocatalytic activity, while the influence of the structure on the optical absorption characteristics of TiO〈sub〉2〈/sub〉 has largely been ignored in the existing explanations. In this paper, optical simulations are introduced into analyzing optical characteristics of TiO〈sub〉2〈/sub〉 Nanofibers with which, the photocatalytic activity enhancement mechanism is further discussed, and a photocatalytic activity enhancement mechanism of TiO〈sub〉2〈/sub〉 Nanofibers is proposed.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Chenhuan Zhao, Xuegang Liu, Wenqiang Zhang, Yun Zheng, Yifeng Li, Bo Yu, Jianchen Wang, Jing Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To make full use of the advantages of solid oxide cells (SOCs) under actual operating conditions, hetero-structured La〈sub〉0.6〈/sub〉Sr〈sub〉0.4〈/sub〉CoO〈sub〉3-δ〈/sub〉/LaSrCoO〈sub〉4±δ〈/sub〉 (LSC〈sub〉113/214〈/sub〉) thin film electrodes are prepared and investigated by a novel high temperature micro-probe electrochemical test platform for SOCs. The results show that the surface exchange coefficient (k〈sup〉q〈/sup〉) of LSC〈sub〉113/214〈/sub〉 thin films is 3–10 times higher than that of single phase LSC〈sub〉113〈/sub〉 in 773–1123 K. ToF-SIMS and XPS characterizations show that LSC〈sub〉113/214〈/sub〉 hetero-interface leads to Sr enrichment at interfacial region and stabilizes it against detrimental Sr segregation. This hetero-interface further induces increased number of active oxygen vacancies and leads to accelerated oxygen exchange kinetics by raising O 2p center closer to Fermi level. This work provides significantly enhanced ORR/OER activity of hetero-structured LSC〈sub〉113/214〈/sub〉 oxygen electrode at operation conditions and brings substantial technical benefits for the SOC systems.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Penghui Feng, Luying Zhu, Yang Zhang, Fusheng Yang, Zhen Wu, Zaoxiao Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As the well-known solid hydrogen storage materials, metal hydrides (MHs) have been developed systematically for decades. During recent years, due to the development of thermal energy storage (TES) market, they have also received much attention gradually as the excellent TES materials because of the high energy density, low cost, and good reversibility. In this study, the stabilized discharging performance of an MH reactor for TES was investigated by numerical simulation. A mathematical model combining multi-physics and proportional-integral controller was established. Based on finite-time thermodynamics, gravimetric exergy-output rate (〈em〉GEOR〈/em〉) considering the control requirement, finite-material, and finite-time constraints was defined. For a given reactor, the output temperature setting could be optimized based on 〈em〉GEOR〈/em〉. Besides, the effects of the reactor parameters on the optimum output temperature setting were systematically studied. The heat transfer analysis indicated the occurrence of the axial non-uniform reaction in the bed due to the inherent increase in the temperature of heat transfer fluid, resulting in the decrease of both 〈em〉GEOR〈/em〉 and material availability. Accordingly, a new tapered bed structure (〈em〉L〈/em〉/〈em〉D〈/em〉〈sub〉o〈/sub〉 = 600/50 mm) was proposed to effectively improve the discharging efficiency from 76 to 90% and 〈em〉GEOR〈/em〉 from 65 to 120 W kg〈sup〉−1〈/sup〉, which provides a helpful guidance for the advanced designing and construction of MH reactor for the practical TES applications.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 4 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): P. Karthik, T.R. Naveen Kumar, B. Neppolian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) is one of the promising two-dimensional metal-free photocatalysts for solar water splitting. Regrettably, the fast electron-hole pair recombination of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 reduces their photocatalytic water splitting efficiency. In this work, we have synthesized the CuO/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 heterojunction via wet impregnation followed by a calcination method for photocatalytic H〈sub〉2〈/sub〉 production. The formation of CuO/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 heterojunction was confirmed by XRD, UV–vis and PL studies. Notably, the formation of heterojunction not only improved the optical absorption towards visible region and also enhanced the carrier generation and separation as confirmed by PL and photocurrent studies. The photocatalytic H〈sub〉2〈/sub〉 production results revealed that CuO/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst demonstrated the increased photocatalytic H〈sub〉2〈/sub〉 production rate than bare g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. The maximum H〈sub〉2〈/sub〉 production rate was obtained with 4 wt % CuO loaded g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst. Importantly, the rate of H〈sub〉2〈/sub〉 production was further improved by introducing simple redox couple Co〈sup〉2+〈/sup〉/Co〈sup〉3+〈/sup〉. Addition of Co〈sup〉2+〈/sup〉 during photocatalytic H〈sub〉2〈/sub〉 production shuttled the photogenerated holes by a reversible conversion of Co〈sup〉2+〈/sup〉 to Co〈sup〉3+〈/sup〉 with accomplishing water oxidation. The effective shuttling of photogenerated holes decreased the election-hole pair recombination and thereby enhancing the photocatalytic H〈sub〉2〈/sub〉 production rate. It is worth to mention that the addition of Co〈sup〉2+〈/sup〉 with 4 wt % CuO/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst showed ∼7.5 and ∼2.0 folds enhanced photocatalytic H〈sub〉2〈/sub〉 production rate than bare g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Co〈sup〉2+〈/sup〉 and CuO/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalysts. Thus, we strongly believe that the present simple redox couple mediated charge carrier separation without using noble metals may provide a new idea to reduce the recombination rate.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0360319919322566-fx1.jpg" width="268" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): B.A. Braz, V.B. Oliveira, A.M.F.R. Pinto〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉A great challenge in a passive direct methanol fuel cell (pDMFC) is how to reduce both methanol and water crossover, from the anode to the cathode side, without significant losses on its power output. Different approaches including improving the membrane and modifying the cell structure and materials have been proposed in the last years.〈/p〉 〈p〉In this work, an experimental study was carried out to evaluate the effect of the cathode diffusion layer (CDL) properties on the power output of a pDMFC. Towards a cost reduction, lower catalyst loadings were used on both anode and cathode electrodes. Since the main goal was the optimization of a pDMFC using the materials commercially available, different carbon-fibber materials were employed as CDL. The experimental results were analysed based on the polarization curves and electrochemical impedance spectroscopy measurements with innovative electric equivalent circuit allowing the identification of the different losses, including the activation resistance of the parasitic cathode methanol oxidation.〈/p〉 〈p〉A maximum power density of 3.0 mW/cm〈sup〉2〈/sup〉 was obtained using carbon cloth with a lower thickness as CDL and a methanol concentration of 5 M.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): A. Herrmann, A. Mädlow, H. Krause〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The project H2home – decentralised energy supply by hydrogen fuel cells – is part of the HYPOS initiative (Hydrogen Power Storage & Solutions East German) and has the aim to develop an embedded system suitable for the highly efficient use of electrical, thermal and cooling energy provided by green hydrogen in domestic applications. This system is characterized by a hydrogen CHP plant based on a low temperature PEM fuel cell and a hydrogen-based heat generator module with the application of condensation technology as well as an integrated solution for the use of electrical energy in an AC and DC grid through power electronic components. The electric efficiency of the CHP is nearly 50% and the total efficiency higher than 95%.〈/p〉 〈p〉To evaluate the performance of the proposed technology the first step was to model a reference case using the simulation tool TRNSYS〈sup〉®〈/sup〉. Therefore, a multi-family house with 16 residential units was chosen. Within the next step different technologies for the energy supply in complex buildings were identified and evaluated. For this purpose, various Key Performance Indicators (KPI's) have been defined and summarized in three main groups allowing a technical, ecological and economical comparison of the selected technologies. The method as well as the main results of the KPI investigations will be explained in the present paper.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Karin Stehlík, Martin Tkáč, Karel Bouzek〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Although activities in hydrogen technologies in the Czech Republic date back to the 60'ies of the 20th century, significant progress in research and implementation appeared only in the 21st century. The acceleration is linked to the foundation of the Czech Hydrogen Technology Platform (HYTEP) in 2007. The mission of HYTEP is to inform and coordinate implementation of hydrogen economy in the Czech Republic.〈/p〉 〈p〉The last three years brought visible changes. The most important one is that hydrogen mobility is part of the national action plan for clean mobility. During the conference WHTC 2017 in Prague the Ministry of Transport and the Ministry of Environment announced support for construction of over 100 hydrogen refilling stations and more than 100,000 hydrogen cars and buses until 2030. Thanks to this governmental activities also first commercial subject developed plans how utilize the potential of hydrogen technologies.〈/p〉 〈p〉In the future HYTEP has the ambition to initiate coordination with other former East Bloc countries. The objective is to strengthen active participation of this region in European efforts and to link it to European networks and strategies to turn regional stakeholders into active participants in hydrogen technologies.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Wei-Chieh Chung, Yun-En Lee, Moo-Been Chang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Anthropogenic emission of CH〈sub〉4〈/sub〉 and CO〈sub〉2〈/sub〉 contributes for most of global warming. Hence, simultaneous conversion of CH〈sub〉4〈/sub〉 and CO〈sub〉2〈/sub〉 into syngas (dry reforming of methane) can be a promising way to alleviate climate change. In this work, we developed a series of perovskite-type photocatalysts, based on LaFeO〈sub〉3〈/sub〉 with various calcination temperatures to combine with a spark discharge reactor to form a hybrid plasma photocatalysis reactor. The hybrid reactor is applied for dry reforming of methane to investigate the syngas generation rate and to reveal possible interactions between plasma and photocatalyst. Results show that LFO600-packed bed has the best CH〈sub〉4〈/sub〉 and CO〈sub〉2〈/sub〉 conversions and syngas generation efficiency of 53.6%, 40.0% and 18.4 mol/kWh, respectively. The enhancement of syngas generation rate can be attributed to synergies between LFO and plasma. Furthermore, changing calcination temperature of photocatalyst also leads to variable characteristics of photocatalyst and hence plasma photocatalysis performance for syngas production.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Odtsetseg Myagmarjav, Jin Iwatsuki, Nobuyuki Tanaka, Hiroki Noguchi, Yu Kamiji, Ikuo Ioka, Shinji Kubo, Mikihiro Nomura, Tetsuya Yamaki, Shinichi Sawada, Toshinori Tsuru, Masakoto Kanezashi, Xin Yu, Masato Machida, Tatsumi Ishihara, Hiroaki Abekawa, Masahiko Mizuno, Tomoyuki Taguchi, Yasuo Hosono, Yoshiro Kuriki〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Thermochemical hydrogen production has attracted considerable interest as a clean energy solution to address the challenges of climate change and environmental sustainability. The thermochemical water-splitting iodine-sulfur (IS) process uses heat from nuclear or solar power and thus is a promising next-generation thermochemical hydrogen production method that is independent of fossil fuels and can provide energy security. This paper presents the current state of research and development (R&D) of the IS process based on membrane techniques using solar energy at a medium temperature of 600 °C. Membrane design strategies have the most potential for making the IS process using solar energy highly efficient and economical and are illustrated here in detail. Three aspects of membrane design proposed herein for the IS process have led to a considerable improvement of the total thermal efficiency of the process: membrane reactors, membranes, and reaction catalysts. Experimental studies in the applications of these membrane design techniques to the Bunsen reaction, sulfuric acid decomposition, and hydrogen iodide decomposition are discussed.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Yi-Hsuan Liang, Ming-Wei Liao, Mrinalini Mishra, Tsong-Pyng Perng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Based on the Z-scheme mechanism, the combination of two semiconductors with suitable bandgaps can reduce the recombination rate of electrons and holes in a single material to enhance photocatalytic hydrogen evolution. Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉 with suitable band gap positions is a potentially promising material for photocatalysis. In order to raise the hydrogen production rate, ZnO nanocrystals were deposited by atomic layer deposition (ALD) on Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉 to form a direct Z-scheme structure, ZnO@Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉. The ALD cycle number varied from 200 to 500. All of the direct Z-scheme samples exhibited much higher hydrogen evolution efficiencies than Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉, ZnO, and the indirect Z-scheme, with the order of ZnO300@Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉〉ZnO200@Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉〉ZnO400@Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉〉ZnO500@Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉. Because of the uniform distribution, discrete particles, and proper size of ZnO, ZnO300@Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉 showed the highest hydrogen evolution rate, being about 500 μmol/g-h. With 400 or 500 ALD cycles, the larger particles of ZnO would overlap with each other to form a continuous layer on Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉, thus reducing the exposure of Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉 to the light and water for producing hydrogen.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 4 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy〈/p〉 〈p〉Author(s): Ahmed Sadeq Al-Fatesh, Jehad K. Abu-Dahrieh, Hanan Atia, Udo Armbruster, Ahmed A. Ibrahim, Wasim U. Khan, Ahmed Elhag Abasaeed, Anis H. Fakeeha〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, the effect of pre-treatment and calcination temperature on a series of 5%Co/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-ZrO〈sub〉2〈/sub〉, 5%Ni/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-ZrO〈sub〉2〈/sub〉 and 2.5%Co-2.5%Ni/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-ZrO〈sub〉2〈/sub〉 catalysts for dry reforming of methane was investigated. Main focus of our research was to improve the catalyst stability by proper pre-treatment and reaction conditions. The first approach aimed at the catalyst pre-treatment by using bimetallic systems and the second strategy at the 〈em〉in situ〈/em〉 suppression of coke. The catalytic activity of bimetallic system was indeed higher compared to the monometallic in the temperature range of 500–800 °C (space velocity 18000 ml h〈sup〉−1〈/sup〉·g〈sub〉cat〈/sub〉〈sup〉−1〈/sup〉, CH〈sub〉4〈/sub〉/CO〈sub〉2〈/sub〉 = 1). The bimetallic catalyst calcined at 800 °C showed highest CH〈sub〉4〈/sub〉 conversion without deactivation and gave a H〈sub〉2〈/sub〉/CO ratio of 91% and 0.96, respectively, and good stability with less coke deposition over 28 h at 800 °C reaction temperature. This improvement is assigned to the synergism between Co and Ni, their high dispersion according to interaction with support. It has been shown in our work that pretreatment temperatures and atmospheres have strong impact on stability of the catalyst. TEM, XRD and TPO investigations confirmed that the slight catalyst deactivation was related to the formation of multiwall carbon nanotubes with hollow inner tube structure. The addition of small amounts of steam or oxygen during DRM improved both the catalyst activity and stability as the bimetallic catalyst lost around 9.4% conversion in DRM, 5.4% in presence of water and only 3.2% in presence of O〈sub〉2〈/sub〉.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Jakub Kupecki, Ryszard Kluczowski, Davide Papurello, Andrea Lanzini, Michał Kawalec, Mariusz Krauz, Massimo Santarelli〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The current study was oriented at analyzing the performance of an anode-supported solid oxide fuel cell produced using high-pressure injection molding. The cell with a total thickness of 550 μm was produced in the Ceramic Department (CEREL) of the Institute of Power Engineering in Poland and experimentally analyzed in the Energy Department (DENERG) of Politecnico di Torino in Italy. The high-pressure injection molding technique was applied to produce a 500 μm thick anode support NiO/8YSZ 66/34 wt% with porosity of 25 vol%. The screen printing method was used to print a 3 μm thick NiO anode contact layer, 7 μm thick NiO/8YSZ 50/50 wt% anode functional layer, 4 μm thick 8YSZ dense electrolyte, 1.5 μm thick Gd〈sub〉0,1〈/sub〉Ce〈sub〉0,9〈/sub〉O〈sub〉2〈/sub〉 barrier layer and a 30 μm thick La〈sub〉0,6〈/sub〉Sr〈sub〉0,4〈/sub〉Fe〈sub〉0,8〈/sub〉Co〈sub〉0,2〈/sub〉O〈sub〉3–δ〈/sub〉 cathode with porosity 25 vol%.〈/p〉 〈p〉The experimental characterization was done at two temperature levels: 750 and 800 °C under fixed anodic and cathodic flow and compositions. The preliminary studies on the application of high-pressure injection molding are discussed together with the advantages of the technology. The performance of two generations of anode-supported cells is compared with data of reference cells with supports obtained using tape casting.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Tian-Feng Hou, Arunkumar Shanmugasundaram, Mostafa Afifi Hassan, Muhammad Ali Johar, Sang-Wan Ryu, Dong-Weon Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In present work, we report a facile fabrication process to improve the photoelectrochemical (PEC) performance of ZnO-based photoelectrodes. In order to achieve that, the Cu〈sub〉2〈/sub〉O nanocubes are cathodic-deposited on the as-prepared ZnO nanorods. Then rGO nanosheets are electrodeposited on the ZnO/Cu〈sub〉2〈/sub〉O heterostructures. The fabricated photoelectrodes are systematically studied in detail by different characterization techniques such as powder X-ray diffraction, micro-Raman, X-ray photoelectron spectroscopy, ultraviolet diffused reflectance spectroscopy and photoluminescence spectroscopy analysis. Morphologies of the fabricated photoelectrodes are investigated through electron microscopy in scanning and transmission mode. To evaluate the PEC performance of the fabricated photoelectrodes, the line scan voltammetry (LSV) measurement is performed using a three-electrode system in 0.5-M Na〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 electrolyte solution under stimulated light illumination at 100 mW/cm〈sup〉2〈/sup〉 from a 300-W Xenon Arc lamp coupled with an AM 1.5G filter using a three-electrode system. The photocurrent measurement demonstrates that the photoelectrodes based on ZnO/Cu〈sub〉2〈/sub〉O/rGO possess enhanced PEC performance compared to the pristine ZnO and ZnO/Cu〈sub〉2〈/sub〉O photoelectrodes. The photocurrent density of ZnO/Cu〈sub〉2〈/sub〉O/rGO-15 photoelectrode (10.11 mA/cm〈sup〉2〈/sup〉) is ∼9 and ∼3 times higher than the photoelectrodes based on pristine ZnO (1.06 mA/cm〈sup〉2〈/sup〉) and ZnO/Cu〈sub〉2〈/sub〉O (3.22 mA/cm〈sup〉2〈/sup〉). The enhanced PEC performance of ZnO/Cu〈sub〉2〈/sub〉O/rGO photoelectrode is attributed to the excellent light absorption properties of Cu〈sub〉2〈/sub〉O and excellent catalytic and charge transport properties of rGO. Experimental results reveal that the proposed functional nanomaterials have a great potential in water splitting applications.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The improved PEC performance of the ZnO/Cu〈sub〉2〈/sub〉O/rGO hybrid photoelectrodes is attributed to (i) excellent crystalline nature of the as-prepared ZnO NRs and Cu〈sub〉2〈/sub〉O nanocubes, (ii) large light absorption property of the Cu〈sub〉2〈/sub〉O nanocubes, (iii) high electrical conduction effect and excellent charge transport property of the rGO nanosheets, (iv) electric effect induced by the heterojunction between the vertically aligned ZnO NRs, Cu〈sub〉2〈/sub〉O nanocubes and rGO nanosheets (Scheme 2) and (v) excellent electron acceptor and passivation layer of rGO. All these factors coupled together contribute to the excellent PEC performance of ZnO/Cu〈sub〉2〈/sub〉O/rGO hybrid based photoelectrodes.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S036031991831646X-fx1.jpg" width="221" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 19 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 35〈/p〉 〈p〉Author(s): Masoud Rokni〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fossil fuels are stored energy during millions of years and we are using it in a rate that new fuels cannot be formed. Renewable energies are not available all the time and there is a need to find ways to store them. One way of storing renewable energies is in fuel form, similar to the fossil fuels and then use this stored fuel whenever needed. The plant design proposed in this paper consists of Dish-Stirling collectors supported by a reversible solid oxide cell acting as a power generator and storage unit, and therefore offering dispatchable power on demand. Further, the system reuses the waste heat for seawater desalination. The present work is an analytical study in which the performance evaluation of a self-sustainable polygeneration system with integrated hydrogen production, power generation, and freshwater production is conducted. An evaluation for selected days, representative for summer, fall, winter and spring in an area with low solar irradiation is studies to investigate the potential of this system to supply 500 kW continuously and simultaneously producing a considerable amount of freshwater. The study shows that the plant can produced hydrogen even in low irradiation winter days together with at least 6500 L of freshwater daily.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 26 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Hydrogen Energy, Volume 44, Issue 36〈/p〉 〈p〉Author(s): Zhentao Wang, Yanwei Zeng, Chuanming Li, Zhupeng Ye, Yuan Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The electrochemical properties of bi-layered electrolytes GDC(Gd〈sub〉0.1〈/sub〉Ce〈sub〉0.9〈/sub〉O〈sub〉1.95〈/sub〉)/YSZ(Y〈sub〉0.16〈/sub〉Zr〈sub〉0.84〈/sub〉O〈sub〉1.92〈/sub〉), ESB(Er〈sub〉0.4〈/sub〉Bi〈sub〉1.6〈/sub〉O〈sub〉3〈/sub〉)/GDC and ESB/YSZ with different layer thickness fractions in the temperature range from 400 to 800 °C have been investigated by simulating calculations based on a charge transport continuity equation and the characteristic conductivity parameters of YSZ, GDC and ESB. It has been found that the model cells with ESB/GDC and ESB/YSZ bi-layered electrolytes can render a higher maximum power density that increases with the ESB layer thickness than those with GDC/YSZ bi-layered electrolytes in the studied temperature range. While the oxygen partial pressure at the interface of ESB/GDC is much lower than that of ESB/YSZ electrolyte with the same ESB thickness fraction, a higher interfacial oxygen partial pressure than the critical decomposition value of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 can be achieved in the ESB/YSZ electrolytes even with small YSZ thickness fractions. This result strongly suggests that the ESB/YSZ, instead of ESB/GDC, would be a thermodynamic stable bi-layered electrolyte with high output power density for potential applications in the intermediate to low temperature SOFCs.〈/p〉〈/div〉 〈/div〉