ALBERT

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Contaminant Hydrology, Volume 226〈/p〉 〈p〉Author(s): Mehrdad Bastani, Thomas Harter〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Nitrate in drinking water may cause serious health problems for consumers. Agricultural activities are known to be the main source of groundwater nitrate contaminating rural domestic and urban public water supply wells in farming regions. Management practices have been proposed to reduce the amount of nitrate in groundwater, including improved nutrient management practices and “pump and fertilize” with nitrate-affected irrigation wells. Here, we evaluate the feasibility and long-term impacts of agricultural managed aquifer recharge (Ag-MAR) in the source area of public water supply wells. A numerical model of nitrate fate and transport was developed for the Modesto basin, part of California's Central Valley aquifer system. The basin is representative of semi-arid agricultural regions around the world with a diversity of crop types, overlying an unconsolidated sedimentary aquifer system. A local public supply well in an economically disadvantaged community surrounded by farmland was the focus of this study. Model scenarios implemented include business as usual, alternative low-impact crops, and Ag-MAR in the source area of the public supply well. Alternative nutrient management and recharge practices act as remediation tools in the area between farmland and the public supply well. Improved agricultural source area management practices are shown to be an effective tool to maintain or even enhance groundwater quality in the targeted supply well while remediating ambient groundwater.〈/p〉 〈p〉Best results are obtained when lowering nitrate load while also increasing recharge in the source area simultaneously. This scenario reduced nitrate in the supply well's drinking water by 80% relative to the business as usual scenario. It also remediated ambient groundwater used by domestic wells between the source area farmlands and the supply well and showed 60% more reduction of nitrate after 60 years of application. Increasing recharge led to shorter initial response time (five years) and showed the most sustainable impact. Our analysis further suggests that Ag-MAR in a highly discontinuous, wide-spread pattern leads to slow water quality response and may not yield sufficient water quality improvements.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Contaminant Hydrology〈/p〉 〈p〉Author(s): Héloïse A.A. Thouement, Tomasz Kuder, Timo J. Heimovaara, Boris M. Van Breukelen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Back-diffusion of chlorinated ethenes (CEs) from low-permeability layers (LPLs) causes contaminant persistence long after the primary spill zones have disappeared. Naturally occurring degradation in LPLs lowers remediation time frames, but its assessment through sediment sampling is prohibitive in conventional remediation projects. Scenario simulations were performed with a reactive transport model (PHT3D in FloPy) accounting for isotope effects associated with degradation, sorption, and diffusion, to evaluate the potential of CSIA data from aquifers in assessing degradation in aquitards. The model simulated a trichloroethylene (TCE) DNAPL and its pollution plume within an aquifer-aquitard-aquifer system. Sequential reductive dechlorination to ethene and sorption were uniform in the aquitard and did not occur in the aquifer. After 10 years of loading the aquitard through diffusion from the plume, subsequent source removal triggered release of TCE by back-diffusion. In the upper aquifer, during the loading phase, δ〈sup〉13〈/sup〉C-TCE was slightly enriched (up to 2‰) due to diffusion effects stimulated by degradation in the aquitard. In the upper aquifer, during the release phase, (i) source removal triggered a huge δ〈sup〉13〈/sup〉C increase especially for higher CEs, (ii) moreover, downstream decreasing isotope ratios (caused by downgradient later onset of the release phase) with temporal increasing isotope ratios reflect aquitard degradation (as opposed to downstream increasing and temporally constant isotope ratios in reactive aquifers), and (iii) the carbon isotope mass balance (CIMB) enriched up to 4‰ as lower CEs (more depleted, less sorbing) have been transported deeper into the aquitard. Thus, enriched CIMB does not indicate oxidative transformation in this system. The CIMB enrichment enhanced with more sorption and lower aquitard thickness. Thin aquitards are quicker flushed from lower CEs leading to faster CIMB enrichment over time. CIMB enrichment is smaller or nearly absent when daughter products accumulate. Aquifer CSIA patterns indicative of aquitard degradation were similar in case of linear decreasing rate constants but contrasted with previous simulations assuming a thin bioactive zone. The Rayleigh equation systematically underestimates the extent of TCE degradation in aquifer samples especially during the loading phase and for conditions leading to long remediation time frames (low groundwater flow velocity, thicker aquitards, strong sorption in the aquitard). The Rayleigh equation provides a good and useful picture on aquitard degradation during the release phase throughout the sensitivity analysis. This modelling study provides a framework on how aquifer CSIA data can inform on the occurrence of aquitard degradation and its pitfalls.〈/p〉〈/div〉 〈/div〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ocean Modelling, Volume 140〈/p〉 〈p〉Author(s): Oleg Druzhinin, Yuliya Troitskaya, Wu-ting Tsai, Po-chen Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study is concerned with direct numerical simulation (DNS) of turbulent air flow over a waved water surface. Three-dimensional, turbulent Couette flow is considered in DNS as a model of a constant-flux layer in the marine atmospheric surface layer. Two-dimensional stationary waves at the water surface are prescribed and assumed to be unaffected by the air-flow. We consider capillary-gravity water surface waves and are interested in the influence of “parasitic” capillary ripples riding on the carrier, energy-containing waves, on the properties of the air-flow. The surface waves are prescribed and considered to be stationary, the capillaries being in phase with the carrier wave. The surface elevations spectra are also prescribed and mimicking stationary capillaries riding on Stokes waves observed in a 2D numerical simulation of water-surface capillary-gravity waves by Hung & Tsai (2009). The bulk air velocity and the carrier water surface waves lengths are considered in our DNS in the range of 3 to 5 m/s and 3 to 7 cm, respectively. Under these conditions, the capillaries are found to be submerged within the viscous sublayer of the atmospheric boundary layer. Our DNS results show that although the flow fields are characterized by instantaneous separations of the boundary layer, the ensemble (wave-phase) averaged flow fields are non-separating and well predicted by a quasilinear theoretical model. We find also that capillaries mitigate the development of coherent (horse-shoe) vortex structures as compared to the no-ripples flow-case. We further use DNS results and quasilinear model formulation to parameterize the water surface roughness height in terms of critical layer thickness and the amplitude of a dominant, energy-containing harmonic of the water surface elevation spectrum.〈/p〉〈/div〉 〈/div〉

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

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part F: Traffic Psychology and Behaviour, Volume 64〈/p〉 〈p〉Author(s): Kayla Fleskes, David S. Hurwitz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉One proposed benefit of automated vehicles (AVs) is their potential to mitigate the occurrence of serious crashes due to human error or poor decision making while driving. However, there are still many concerns associated with the use of SAE Level 3 AVs, which require intervention by a human driver after a take-over request (TOR). These concerns intensify when vulnerable road users, such as bicyclists, are introduced to the driving environment. The objective of this research was to investigate how human drivers of AVs interact with bicyclists during a right-turn maneuver after receiving a TOR. Changes in driver performance, including visual attention and crash avoidance behavior, were measured by using a high-fidelity driving simulator, with 43 participants each completing 18 right-turn maneuvers. Three independent variables were studied: the bicyclist’s proximity to the intersection, the driver’s proximity from the intersection when the TOR was received, and the driver’s engagement in a distracting secondary task (a game on a tablet). In general, the results showed that the introduction of the secondary task led to decreased driver performance with respect to time-to-collision and the time that it took a driver to first identify the bicyclist on the roadway. When given more time to react before the intersection, drivers generally had safer interactions with the bicyclist.〈/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-S136984781830411X-ga1.jpg" width="426" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

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

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

Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Quaternary International〈/p〉 〈p〉Author(s): Brian F. Codding, Adrian R. Whitaker, Nathan E. Stevens〈/p〉

Description: 〈p〉Publication date: 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Quaternary Science Reviews, Volume 218〈/p〉 〈p〉Author(s): Athanassios Athanassiou, Alexandra A.E. van der Geer, George A. Lyras〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Eastern Mediterranean islands, most of which belong to the Aegean archipelago, have a complex biogeographic history, which puts its stamp on their fauna and flora. A now extinct but most important faunal component, in terms of geographic spread and taxonomic diversity, are the elephants. The Eastern Mediterranean islands are particularly rich in Pleistocene endemic elephant localities, which preserve samples of extinct endemic populations. These were either descendants of the European straight-tusked elephant 〈em〉Palaeoloxodon antiquus〈/em〉 or the Southern mammoth, 〈em〉Mammuthus meridionalis〈/em〉. Their presence, history and palaeobiogeography has been documented only for Cyprus, Crete, Kasos, Rhodes, Tilos, Kýthera, Naxos, and Delos. For six other islands only anecdotal references exist in the literature: Kálymnos, Astypálaia, Milos, Sériphos, Kýthnos and Paros. Here, we provide an update on previously published specimens and taxa, describe previously undescribed specimens that were relocated in museum collections, as well as recently excavated specimens, and put these in the context of island palaeobiogeography. We conclude that dwarf elephants, endemic to their palaeo-island, lived on the islands of palaeo-Cyclades, Astypálaia, Crete, Kasos–Kárpathos–Saría, Tilos, Rhodes and Cyprus, whereas the elephants from Kephallenía, Kálymnos and Kýthera are indistinguishable on the species level from mainland 〈em〉Palaeoloxodon antiquus〈/em〉. Elephant fossils of unresolved taxonomic status are reported from five present-day islands. The Eastern Mediterranean endemic elephants likely derived from separate and independent colonisation events from the mainland. No island supported more than one proboscidean species at any time. We found that isolation had no effect on the degree of dwarfism, but that there exists a threshold of about 6–10 km distance between the island and the mainland, below which no dwarfism evolved, likely as a result of genetic contact with the mainland population. We also found that although island area is correlated with the degree of dwarfism in elephants, other factors, such as the level of interspecific competition, may limit this degree.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment〈/p〉 〈p〉Author(s): Julie A. Fortin, Jeffrey A. Cardille, Elijah Perez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The ongoing march toward freely available, highly pre-processed satellite imagery has given both researchers and the public unprecedented access to a vast and varied data stream teeming with potential. Among many sources, the multi-decade Landsat archive is certainly the best known, but legacy and current data from other sensors is available as well through the USGS data portals: these include CBERS, ASTER, and more. Though the particular band combinations or non-global missions have made their integration into analyses more challenging, these data, in conjunction with the entire Landsat record, are available to contribute to multi-decade surveys of land-cover change.〈/p〉 〈p〉With the goal of tracing forest change through time near the Roosevelt River in the state of Mato Grosso, Brazil, we used BULC and Google Earth Engine to fuse information from 13 space-borne imagers capturing 140 images spanning 45 years. With high accuracy, the resulting time series of classifications shows the timing and location of land-use/land-cover change—both deforestation and regrowth—at sub-annual time scales. Accuracy estimates showed that the synthesized BULC classification time series was better than nearly all of the single-day image classifications, covering the entire study area at sub-annual frequency while reducing the impact of clouds and most unwanted noise as it fused information derived from a wide array of imaging platforms. The time series improved and gradually sharpened as the density of observations increased in recent decades, when there were three or more clear, higher-resolution views of a pixel annually from any sensor combination. In addition to detailing the methodology and results of multi-source data fusion with the BULC approach, this study raises timely points about integrating information from early satellite data sources and from sensors with footprints smaller than Landsat's. There are decades of research deriving sensor-specific techniques for classifying land use and land cover from a single image in a variety of settings. The BULC approach leverages the many successes of single-sensor research and can be used as a straightforward, complementary tool for blending many good-quality mapped classifications from disparate sources into a coherent, high-quality time series.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Quaternary International〈/p〉 〈p〉Author(s): Xiaolin Ren, Duowen Mo, Michael Storozum, Ximena Lemoine, Yanyan Yu, Wanfa Gu, Xingshan Lei, Jiaqiang Zhang, Jianqing Lü, Tristram R. Kidder〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Archaeologists have focused on the social conditions surrounding the development of urbanism around the world, however the environmental impact of these ancient cities remains unclear. In this paper, we present palynological data from the early Bronze Age city of Dongzhao, Henan Province, China. Our data indicate that vegetation change and the development of early urban settlements are closely linked, with the advent of urban development significantly accelerating deforestation and altering the composition of local vegetation communities. The pollen record from Dongzhao provides new evidence to support the claim that urban expansion, coupled with a drying climate and the expansion of agriculture, dramatically reconfigured the landscapes of Bronze Age China.〈/p〉〈/div〉 〈/div〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Advances in Water Resources, Volume 131〈/p〉 〈p〉Author(s): Shaokun He, Shenglian Guo, Kebing Chen, Lele Deng, Zhen Liao, Feng Xiong, Jiabo Yin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The optimal impoundment operation of cascade reservoirs can dramatically improve the utilization of water resources. However, their complex non-convexity and computational costs pose challenges to optimal hydroelectricity output and limit further development of joint operation within larger-scale cascade reservoirs. In recent decades, parallel dynamic programming (PDP) has emerged as a means of alleviating the ‘curse of dimensionality’ in the mid-long term reservoir operation with more involved computing processors. But it still can't effectively solve the daily impoundment operation of more than three reservoirs. Here, we propose a novel method called importance sampling-PDP (IS-PDP) algorithm in which the merits of PDP are integrated with importance sampling and successive approximation strategy. Importance sampling is first used to construct the state vectors of each period by introducing ‘Manhattan distance’ in the discrete state space. Then the PDP recursive equation is used to find an improved solution during the iteration. The IS-PDP method is tested to optimize hydropower output for the joint operation of an 11-reservoir system located in the upper Yangtze River basin of China after establishing impoundment operation by advancing impoundment timings and rising water levels. We find that our methodology could effectively deal with the ‘curse of dimensionality’ for such mega reservoir systems and make better use of water resources in comparison to the Standard Operation Policy (SOP). Given its computational efficiency and robust convergence, the methodology is an attractive alternative for non-convex operation of large-scale cascade reservoirs.〈/p〉〈/div〉

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

Description: 〈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〉

Description: 〈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〉

Description: 〈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〉