ALBERT

Description: When cumulonimbus clouds aggregate, developing into a single entity with precipitation covering a horizontal scale of hundreds of kilometers, they are called mesoscale convective systems (MCSs). They account for much of Earth’s precipitation, generate severe weather events and flooding, produce prodigious cirriform anvil clouds, and affect the evolution of the larger-scale circulation. Understanding the inner workings of MCSs has resulted from developments in observational technology and modeling. Time–space conversion of ordinary surface and upper-air observations provided early insight into MCSs, but deeper understanding has followed field campaigns using increasingly sophisticated radars, better aircraft instrumentation, and an ever-widening range of satellite instruments, especially satellite-borne radars. High-resolution modeling and theoretical insights have shown that aggregated cumulonimbus clouds induce a mesoscale circulation consisting of air overturning on a scale larger than the scale of individual convective up- and downdrafts. These layers can be kilometers deep and decoupled from the boundary layer in elevated MCSs. Cooling in the lower troposphere and heating aloft characterize the stratiform regions of MCSs. As a result, long-lived MCSs with large stratiform regions have a top-heavy heating profile that generates potential vorticity in midlevels, thus influencing the larger-scale circulation within which the MCSs occur. Global satellite data show MCSs varying in structure, depending on the prevailing large-scale circulation and topography. These patterns are likely to change with global warming. In addition, environmental pollution affects MCS structure and dynamics subtly. Feedbacks of MCSs therefore need to be included or parameterized in climate models.

Description: The central change in understanding of the ocean circulation during the past 100 years has been its emergence as an intensely time-dependent, effectively turbulent and wave-dominated, flow. Early technologies for making the difficult observations were adequate only to depict large-scale, quasi-steady flows. With the electronic revolution of the past 50+ years, the emergence of geophysical fluid dynamics, the strongly inhomogeneous time-dependent nature of oceanic circulation physics finally emerged. Mesoscale (balanced), submesoscale oceanic eddies at 100-km horizontal scales and shorter, and internal waves are now known to be central to much of the behavior of the system. Ocean circulation is now recognized to involve both eddies and larger-scale flows with dominant elements and their interactions varying among the classical gyres, the boundary current regions, the Southern Ocean, and the tropics.

Description: Although atmospheric observing systems were already an important part of meteorology before the American Meteorological Society was established in 1919, the past 100 years have seen a steady increase in their numbers and types. Examples of how observing systems were developed and how they have enabled major scientific discoveries are presented. These examples include observing systems associated with the boundary layer, the upper air, clouds and precipitation, and solar and terrestrial radiation. Widely used specialized observing systems such as radar, lidar, and research aircraft are discussed, and examples of applications to weather forecasting and climate are given. Examples drawn from specific types of chemical measurements, such as ozone and carbon dioxide, are included. Sources of information on observing systems, including other chapters of this monograph, are also discussed. The past 100 years has been characterized by synergism between societal needs for weather observations and the needs of fundamental meteorological research into atmospheric processes. In the latter half of the period, observing system improvements have been driven by the increasing demands for higher-resolution data for numerical models, the need for long-term measurements, and for more global coverage. This has resulted in a growing demand for data access and for integrating data from an increasingly wide variety of observing system types and networks. These trends will likely continue.

Description: The polar regions present several unique challenges to meteorology, including remoteness and a harsh environment. We summarize the evolution of polar meteorology in both hemispheres, beginning with measurements made during early expeditions and concluding with the recent decades in which polar meteorology has been central to global challenges such as the ozone hole, weather prediction, and climate change. Whereas the 1800s and early 1900s provided data from expeditions and only a few subarctic stations, the past 100 years have seen great advances in the observational network and corresponding understanding of the meteorology of the polar regions. For example, a persistent view in the early twentieth century was of an Arctic Ocean dominated by a permanent high pressure cell, a glacial anticyclone. With increased observations, by the 1950s it became apparent that, while anticyclones are a common feature of the Arctic circulation, cyclones are frequent and may be found anywhere in the Arctic. Technology has benefited polar meteorology through advances in instrumentation, especially autonomously operated instruments. Moreover, satellite remote sensing and computer models revolutionized polar meteorology. We highlight the four International Polar Years and several high-latitude field programs of recent decades. We also note outstanding challenges, which include understanding of the role of the Arctic in variations of midlatitude weather and climate, the ability to model surface energy exchanges over a changing Arctic Ocean, assessments of ongoing and future trends in extreme events in polar regions, and the role of internal variability in multiyear-to-decadal variations of polar climate.

Description: The field of atmospheric science has been enhanced by its long-standing collaboration with entities with specific needs. This chapter and the two subsequent ones describe how applications have worked to advance the science at the same time that the science has served the needs of society. This chapter briefly reviews the synergy between the applications and advancing the science. It specifically describes progress in weather modification, aviation weather, and applications for security. Each of these applications has resulted in enhanced understanding of the physics and dynamics of the atmosphere, new and improved observing equipment, better models, and a push for greater computing power.

Description: Over the past century, the atmospheric and related sciences have seen incredible advances in our understanding of Earth’s environment and our ability to monitor and predict its behavior. These advances have had a profound impact on society and have been integrated into every aspect of daily life. The American Meteorological Society (AMS) has been instrumental in supporting these advances throughout its first 100 years of existence as a scientific and professional society serving the community of professionals in the atmospheric and related oceanic and hydrologic sciences. AMS has provided opportunities for researchers and practitioners to share their scientific findings and build fruitful collaborations to further the science and its application. Through strategic initiatives at key points in its history, AMS has pushed the science forward—highlighting areas ripe for development, creating frameworks for interdisciplinary interactions, and providing innovative approaches to the dissemination of research results. As a society made up of the scientific community and led by many of the most prominent scientists of their time, AMS has been able to respond to, and often anticipate, the needs of its community.

Description: A century ago, meteorologists regarded tropical cyclones as shallow vortices, extending upward only a few kilometers into the troposphere, and nothing was known about their physics save that convection was somehow involved. As recently as 1938, a major hurricane struck the densely populated northeastern United States with no warning whatsoever, killing hundreds. In the time since the American Meteorological Society was founded, however, tropical cyclone research blossomed into an endeavor of great breadth and depth, encompassing fields ranging from atmospheric and oceanic dynamics to biogeochemistry, and the precision and scope of forecasts and warnings have achieved a level of success that would have been regarded as impossible only a few decades ago. This chapter attempts to document the extraordinary progress in tropical cyclone research over the last century and to suggest some avenues for productive research over the next one.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Alberto Pistocchi, Costanza Calzolari, Francesco Malucelli, Fabrizio Ungaro Study region The plains of Emilia Romagna, Italy. Study focus Urban expansion is among the main causes of increase in flood frequency and intensity in small rural catchments in Europe, and our study region is paradigmatic in this respect. We present here a regional screening-level assessment of soil sealing impacts in terms of increased flood peak discharges and flooding volumes on the secondary drainage network of the plains. We estimate flood peak discharges and flooding volumes through a simple kinematic model with runoff coefficients for the land use of 2008 and 1976. Additionally, we calculate an equivalent compensatory flood detention volume that would enable preserving flood peak discharges as prior to soil sealing (principle of “hydraulic invariance”). The proposed approach is simple and readily applicable to any region facing similar issues, for screening-level assessment of flood hazards over an extended stream network. New hydrological insights for the region The analysis highlights a significant increase in flood hazards throughout the secondary stream network. The impact. Widespread and relatively uniform, is more apparent in smaller catchments and in the case of more permeable soils. This demands retrofitting of the majority of the drainage network and/or significantly higher costs from flooding damages. The analysis suggests that costs of additional flooding after soil sealing may be higher than those of soil sealing impacts compensation through flood detention (hydraulic invariance).

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): M.A. Sarr, O. Seidou, Y. Tramblay, S. El Adlouni Study region The study considers six precipitation stations located in Senegal, West Africa. Senegal is located in the Sahel, an area that is threatened by climate variability and change. Both droughts and extreme rainfall have been an issue in recent years. Study focus Two different statistical downscaling techniques were applied to the outputs of four regional climate models at six selected precipitation stations in Senegal. First, the delta-change method was applied to the mean annual precipitation as well as the 5, 10, 20, 50 and 100-year return period daily precipitation events. Second, a quantile–quantile transformation (QQ) was used to downscale the monthly distributions of precipitation simulated by regional climate models (RCMs). The 5, 10, 20, 50 and 100-year daily precipitation events were afterward calculated. All extreme events were calculated assuming that maximum annual daily precipitations follow the generalized extreme value (GEV) distribution. The two-sided Kolmogorov–Smirnov (KS) test was finally used to assess the performance of the quantile–quantile transformation as well as the GEV distribution fit for the annual maximum daily precipitation. New hydrological insights for the region Results show that the two downscaling techniques generally agree on the direction of the change when applied to the outputs of same RCM, but some cases lead to very different projections of the direction and magnitude of the change. Projected changes indicate a decline in mean precipitation except for one RCM over one region in Senegal. Projected changes in extreme precipitations are not consistent across stations and return periods. The choice of the downscaling technique has more effect on the estimation of extreme daily precipitations of return period equal or greater than ten years than the choice of the climate models.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): J.S. Lessels, T.F.A. Bishop Study region South eastern Australia. Study focus This region is characterised with rainfall events that are associated with large exports of nutrients and sediments. Many water quality monitoring schemes use a form of event-based sampling to quantify these exports. Previous water quality studies that have evaluated different sampling schemes often rely on continuously monitored water quality data. However, many catchment authorities only have access to limited historical data which consists of event-based and monthly routine samples. Therefore there is a need to develop a method that assesses the importance of sampling events using information from limited historical data. This work presents a simulation based approach using unconditional simulation based on historical stream discharge. Such an approach offers site-specific information on optimal sampling schemes. A linear mixed model is used to model the relationship between total phosphorus and stream discharge and the auto-correlation of total phosphorus. New hydrological insights for the region The inclusion of event-based sampling improved annual load estimates of all sites with a maximum RMSE difference of 16.11 tonnes between event-based and routine sampling. Based on the accuracy of annual loads, event-based sampling was found to be more important in catchments with a large relief and high annual rainfall in this region. Using this approach, different sampling schemes can be compared based on limited historical data.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Hayet Chihi, Ghislain de Marsily, Habib Belayouni, Houcine Yahyaoui Study region “Jeffara de Medenine” aquifer system in south-eastern Tunisia. Study focus This study investigates the role of fault structures in the distribution of hydrogeochemical facies and groundwater compartmentalization for the aquifer system. New hydrological insights for the region The proposed methodology, including seismic structural study, hierarchical cluster analysis and geostatistical methods, allowed an efficient multi-element characterization of the spatial patterns of the structural elements in the aquifers and of the hydrogeological parameters used in a spatial cross-correlation to explore the dependence of the geochemical properties in each “geochemical population” on the hosting structural compartment to delineate the different geochemical compartments. The tectonic studies showed that the lateral extent of the aquifers is controlled by normal faults. The multivariate statistical analysis revealed a strong spatial coherence between hydrogeochemical facies clustering and the reservoir compartments at both large and small scales. The kriged maps of major-ion concentrations and of total dissolved solids in the aquifers were then analyzed and compared with the reservoir facies distribution for each compartment, the geometric characteristics of the aquifer, and the piezometric level trends. This allowed to characterize the hydraulic behavior of the Medenine fault and to understand the underlying physical and chemical processes having led to the spatial distribution of the geochemical properties, and thus, the hydrogeochemical functioning of the aquifers.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Marnie L. Atkins, Isaac R. Santos, Damien T. Maher Study region This study investigates dissolved methane distribution in groundwater from the Richmond River Catchment (New South Wales, Australia) before proposed coal seam gas (CSG, or coal bed methane) development. Study focus Unconventional gas exploration has rapidly expanded in recent years. However, the impact of these operations on groundwater systems is poorly understood. A total of 91 groundwater samples were analyzed from 6 geological units. Our observations act as regional baseline research prior to CSG extraction and may assist with long term impact assessment. New hydrological insights for the region Methane was found in all geological units ranging between 0.26 and 4427 μg L −1 (median 10.68 μg L −1 ). Median methane concentrations were highest in chloride-type groundwater (13.26 μg L −1 , n = 58) while bicarbonate-type groundwater had lower concentrations (3.71 μg L −1 ). Groundwater from alluvial sediments had significantly higher median methane concentrations (91.46 μg L −1 ) than groundwater from both the basalt aquifers (0.7 μg L −1 ) and bedrock aquifers (4.63 μg L −1 ); indicating geology was a major driver of methane distribution. Methane carbon stable isotope ratios ranged from –90.9‰ to –29.5‰, suggesting a biogenic origin with some methane oxidation. No significant correlations were observed between methane concentrations and redox indicators (nitrate, manganese, iron and sulphate) except between iron and methane in the Lismore Basalt ( r 2 = 0.66, p 〈 0.001), implying redox conditions were not the main predictor of methane distribution.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Z. Zomlot, B. Verbeiren, M. Huysmans, O. Batelaan Study focus Groundwater is of strategic importance. The accurate estimation of groundwater recharge and assessing the fundamental controlling factors are therefore of utmost importance to protect groundwater systems. We used the spatially-distributed water-balance model WetSpass to estimate long-term average recharge in Flanders. We validated recharge rates with base flow estimates of 67 daily stream flow records using the hydrograph analyses. To this end we performed principal component analysis, multiple linear regression analysis and relative importance analysis to assess the controlling factors of the spatial variation of recharge and base flow with the influencing watershed characteristics. New hydrological insights for the region The average resulting recharge is 235 mm/year and occurs mainly in winter. The overall moderate correlation between base flow estimates and modeled recharge rates indicates that base flow is a reasonable proxy of recharge. Groundwater recharge variation was explained in order of importance by precipitation, soil texture and vegetation cover; while base flow variation was strongly controlled by vegetation cover and groundwater depth. The results of this study highlight the important role of spatial variables in estimation of recharge and base flow. In addition, the prominent role of vegetation makes clear the potential importance of land-use changes on recharge and hence the need to include a proper strategy for land-use change in sustainable management of groundwater resources.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): B. Ibrahim, D. Wisser, B. Barry, T. Fowe, A. Aduna Study region Hydrological observation networks in the West African region are not dense and reliable. Furthermore, the few available discharge data often present significant gaps. The Volta basin, the second largest transboundary basin in the region, is a typical example of a basin with inadequate hydrological networks. Study focus In this study, a prediction approach to determine monthly discharge in ungauged watersheds is developed. The approach is based on the calibration of two conceptual models for gauged watersheds and an estimation of models’ parameters from the physical and climatic characteristics of the watersheds. The models’ parameters were determined for each ungauged watershed through two different methods: the multiple linear regressions and the kriging method. The two methods were first validated on five gauged watersheds and then applied to the three ungauged watersheds. New hydrological insights for the region The application of the two hydrological models on the eight watersheds helped to produce relevant monthly runoff and to establish the annual hydrological balances from 1970 to 2000 for both gauged and ungauged watersheds. The developed method in this study could therefore help estimate runoff time series, which are of crucial importance when it comes to design hydraulic structures such as small reservoirs.

Description: Publication date: Available online 14 August 2015 Source: Journal of Hydrology: Regional Studies Author(s): Mayank Shekhar, Amalava Bhattacharyya Study region Zemu Chuu (river), Lachen, North Sikkim, Eastern Himalaya India. Study focus Using tree-ring data of fir ( Abies densa ) the temporal variation of 222 years January–April mean discharge of Zemu Chuu, upper reaches of the Teesta River at Lachen, North Sikkim Eastern Himalaya was investigated. This was based on linear regression reconstruction model which explained variance of 50.1% during calibration period (AD 1976–1996). The model was verified by reduction of error (RE), sign test (ST), product mean test (Pmt), root mean square error (RMSE) and Durbin–Watson test (DW). The RE never falls below zero suggesting the model had explanatory power over the entire period of reconstruction. New hydrological insights for the region The explored strong relationship between tree ring records and instrumental data enable to develop mean January–April months (premonsoon) river discharge of Zemu Chuu from remote area of Sikkim. Reconstructed data reveals high stream-flow when it is more than the mean plus one standard deviation and as low when flow is less than the mean minus one standard deviation. There were such 23 high discharge and 21 extremely low years over the past AD 1775–1996. This premonsoon reconstruction of river flow would be of great significance when scarcity of water is acute in the North East Himalaya.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Jonathan A. Warrick, John M. Melack, Blair M. Goodridge Study region Coastal watersheds of southern California, United States. Study focus We sought to better understand the rates and variability of suspended-sediment discharge from small coastal watersheds (〈100 km 2 ) of California. Suspended-sediment concentrations and stream discharge were measured with automated samplers near the mouths of four small watersheds (10–56 km 2 ). New hydrological insights for the region The watersheds were found to have suspended-sediment concentrations that extended over five orders of magnitude (1 to over 100,000 mg L −1 ). Sediment concentrations were weakly correlated with discharge ( r 2 = 0.10–0.25), and four types of hysteresis patterns were observed during high flow events (clockwise, counterclockwise, no hysteresis, and complex). Annual sediment yields varied by 400-fold across the four watersheds (e.g., 5–2100 t km −2 yr −1 during the 2003–2006 water years), and sediment discharge was measurably elevated in one watershed that was partially burned by a late summer wildfire. Dozens of high flow events provided evidence that suspended-sediment yields were generally related to peak stream discharge and event-based precipitation, although these relationships were not consistent across the watersheds. This suggests that watersheds smaller than 100 km 2 can provide large – and therefore important – fluxes of sediment to the coast, but that simple techniques to estimate sediment loads, such as sediment rating curves, hydrologic regressions, and extrapolation using global sediment yield relationships that include watershed area as a primary factor, may provide poor results. Graphical abstract

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Chris C. Gianfagna, Chris E. Johnson, David G. Chandler, Charlie Hofmann Study region The Catskills region of New York State is largely forested and dominated hydrologically by stream watersheds with few natural lakes. The area experiences intensive water resources management and ecosystem monitoring due to its strategic role as the principal water supply for New York City. Study focus We analyzed average daily flows in nested and non-nested pairs of gaged watersheds in the Catskills to assess whether daily flow in ungaged watersheds can be calculated based on watershed area ratios. New hydrological insights for the region Watershed area ratio was the most important basin parameter for estimating flow at upstream sites based on downstream flow. The area ratio alone explained 93% of the variance in the slopes of relationships between upstream and downstream flows. Regression analysis indicated that flow at any upstream point can be estimated by multiplying the flow at a downstream reference gage by the watershed area ratio. This method accurately predicted upstream flows at area ratios as low as 0.005. We also observed a very strong relationship ( R 2 = 0.79) between area ratio and flow–flow slopes in non-nested catchments. Our results indicate that a simple flow estimation method based on watershed area ratios is justifiable, and indeed preferred, for the estimation of daily streamflow in ungaged watersheds in the Catskills region.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Alfonso Rivera Study region Canada–USA border. Study focus Since 2005, Canada has followed international developments in transboundary groundwater issues in cooperation with its southern neighbor the United States (USA) within the Internationally Shared Aquifer Resources Management Initiative (ISARM) of UNESCO. As a result, 10 Transboundary Aquifer Systems (TAS) were identified along the border between Canada and the USA. This study is an extensive review of the current state of the 10 TAS. Documentation of scientifically-based knowledge on TAS is an important step in identifying potential issues in policies that might be adopted to address shared water-resource issues. New hydrological insights for the region This analysis emphasizes the need for more scientific data, widespread education and training, and a more clearly defined governments’ role to manage groundwater at the international level. The study reviews the current legal framework and summarises the current scientific knowledge for the TAS with respect to the hydrologic and geologic framework as well as some of the major drivers for supply and demand. It also describes the links, approach and relevance of studies on the TAS to the UN Law of Transboundary Aquifers and on how these might fit in the regional strategy for the assessment and management of the TAS. Clear communication, shared knowledge and common objectives in the management of TAS will prepare the countries for future negotiations and cooperative binational programs.

Description: Publication date: September 2015 Source: Journal of Hydrology: Regional Studies, Volume 4, Part B Author(s): Brioch Hemmings, Daren Gooddy, Fiona Whitaker, W. George Darling, Alia Jasim, Joachim Gottsmann Study region Montserrat, Lesser Antilles, Caribbean. Study focus Analysis of δ 2 H and δ 18 O isotopes, and chlorofluorocarbon (CFC) anthropogenic tracers in Montserrat groundwater provides insights into the age and provenance of the spring waters. New hydrological insights δ 2 H and δ 18 O analysis indicates uniform recharge elevations for groundwaters on Montserrat. CFC-11 and CFC-12 analysis reveals age differences between isotopically similar, high elevation springs and low elevation aquifer waters. Low CFC concentrations within a confined low elevation aquifer suggest water ages of ∼45 years. High CFC concentrations in the northern and western springs are explained by rapid infiltration of cool (high CFC concentration) rainfall into saturated compartments, with flow through the vadose zone to the phreatic zone dominated by compartment flow. Lower CFC concentrations in a number of aligned warmer springs suggest a contribution from older, warmer waters from depth. Temperatures and CFC concentrations indicate older component supply rates of up to 8 L/s to the highest yielding spring on Centre Hills, with contributions of up to 75% in the warmest spring waters.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1

Description: Publication date: Available online 3 April 2015 Source: Journal of Hydrology: Regional Studies Author(s): A. Shahul Hameed , T.R. Resmi , S. Suraj , C. Unnikrishnan Warrier , M. Sudheesh , R.D. Deshpande Study region The Chaliyar river basin, Kerala State, India. Study focus Detailed understanding about spatio-temporal variation in the interaction and exchange of water between surface and sub-surface reservoirs is important for effective watershed management. Spatio-temporal variations in the oxygen isotopic composition ( δ 18 O) were used to understand the interaction between groundwater and river water, and to estimate the groundwater recharge from river water in the Chaliyar river basin. New hydrological insights for the region Based on the spatio-temporal variation in δ 18 O values of river and groundwater and fluctuation in ground water levels, following important inferences are made: (1) estimated river water contribution to post-monsoon groundwater recharge is ∼16% in the lowland coastal area of the Chaliyar river basin and 29% in midland region; (2) northeast winter monsoon rains contribute to the groundwater of Chaliyar river basin only in an insignificant manner, and with a delayed response; (3) unlike river water samples which exhibit both seasonal and spatial variation of more than 3‰, the groundwater samples vary only marginally (∼1‰) between the seasons and across the physiographic zones; (4) groundwater samples exhibit inverse altitude gradient in δ 18 O values in the highland zone, in all the three seasons. This may be due to flow of the isotopically depleted groundwater down the gradient and evaporation of residual water in the upper reaches of the basin.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1 Author(s): Ashish Sharma

Description: Publication date: Available online 16 May 2015 Source: Journal of Hydrology: Regional Studies Author(s): E.H. Elias , A. Rango , C.M. Steele , J.F. Mejia , R. Smith Study region Upper Rio Grande, Colorado and New Mexico, USA. Study focus Climate change is predicted to further limit the water availability of the arid southwestern U.S. We use the snowmelt runoff model to evaluate impacts of climate change on snow covered area (SCA), streamflow timing and runoff volume. Simulations investigate four future conditions using models downscaled to existing climate stations. Twenty-four subbasins of the Upper Rio Grande containing appreciable snowmelt and a long-term gauging station are simulated. New hydrological insights for the region Future annual volume is 193–204 million m 3 more to 448–476 million m 3 less than the pre-climate change value of 2688 million m 3 . There is disparity between increased volume in wetter simulations (+7%) and decreased volume (−18%) in drier simulations. SCA on 1 April reduced by approximately 50% in all but the warmer/wetter climate. Peak flow is 14–24 days early in the future climates. Among the 24 subbasins there is considerable range in mean melt season SCA (−40% to −100%), total volume change (−30% to +57%) and runoff timing advancement indicating that climate change is best evaluated at the subbasin scale. Daily hydrographs show higher streamflow in March and April, but less from mid-May until the end of the water year. The large decrease in volume in May, June and July will compound water management challenges in the region.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1 Author(s): Mohammad Kamruzzaman

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3 Author(s): Jean-Michel Lemieux , Jalil Hassaoui , John Molson , René Therrien , Pierre Therrien , Michel Chouteau , Michel Ouellet Study region This study is conducted in the Magdalen Islands (Québec, Canada), a small archipelago located in the Gulf of St. Lawrence. Study focus This work was undertaken to support the design of a long-term groundwater monitoring network and for the sustainable management of groundwater resources. This study relies mostly on the compilation of existing data, but additional field work has also been carried out, allowing for the first time in the Magdalen Islands, direct observation of the depth and shape of the transition zone between freshwater and seawater under natural conditions. Simulations were conducted along a 2D cross-section on Grande Entrée Island in order to assess the individual and combined impacts of sea-level rise, coastal erosion and decreased groundwater recharge on the position of the saltwater–freshwater interface. The simulations were performed considering variable-density flow and solute transport under saturated-unsaturated conditions. The model was driven by observed and projected climate change scenarios to 2040 for the Magdalen Islands. New hydrological insights for the region The simulation results show that among the three impacts considered, the most important is sea-level rise, followed by decreasing groundwater recharge and coastal erosion. When combined, these impacts cause the saltwater–freshwater interface to migrate inland over a distance of 37 m and to rise by 6.5 m near the coast to 3.1 m further inland, over a 28-year period.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3 Author(s): M.A. Pascolini-Campbell , Richard Seager , David S. Gutzler , Benjamin I. Cook , Daniel Griffin Study region The Gila River, New Mexico, is characterized by two peaks in streamflow: one in the winter–spring (December–May), and summer (August–September). The region is influenced both by Pacific SST variability as well as the North American Monsoon. Study focus The mechanisms responsible for the variability of the winter–spring and summer streamflow peaks are investigated by correlation of streamflow with precipitation and sea surface temperature for 1928–2012. Decadal variability in the flow record is examined for a longer term perspective on Gila River streamflow using tree ring-based reconstructions of the Palmer Drought Severity Index (PDSI) and the Standardized Precipitation Index (SPI). New hydrological insights for the region Results indicate a strong influence of winter–spring precipitation and Pacific SST anomalies on the winter–spring streamflow, with El Niño conditions in the Pacific causing increased precipitation and streamflow. Decadal Pacific variability helps explain the transition from high winter flow in the late 20th century to lower flows in the most recent decade. The summer streamflow has a somewhat weaker correlation with precipitation and Pacific SST than the winter–spring streamflow. Its variability is more likely influenced by local North American Monsoon precipitation variability. PDSI and SPI reconstructions indicate much more severe and extended periods of droughts and pluvials in past centuries as well as periods of concurrent winter and summer drought.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3 Author(s): Tsou Jaw , Jialun Li , Kuo-lin Hsu , Soroosh Sorooshian , Fatima Driouech Study region Morocco (excluding Western Sahara). Study focus This study evaluated Moroccan precipitation, dynamically downscaled (0.18-degree) from three runs of the studied GCM ECHAM5/MPI-OM, under the present-day (1971–2000/20C3M) and future (2036–2065/A1B) climate scenarios. The spatial and quantitative properties of the downscaled precipitation were evaluated by a verified, fine-resolution reference. The effectiveness of the hydrologic responses, driven by the downscaled precipitation, was further evaluated for the study region over the upstream watershed of Oum er Rbia River located in Central Morocco. New hydrological insights for the region The raw downscaling runs reasonably featured the spatial properties but quantitatively misrepresented the mean and extreme intensities of present-day precipitation. Two proposed bias correction approaches, namely stationary Quantile-Mapping (QM) and non-stationary Equidistant CDF Matching model (EDCDFm), successfully reduced the system biases existing in the raw downscaling runs. However, both raw and corrected runs projected great diversity in terms of the quantity of future precipitation. Hydrologic simulations performed by a well-calibrated Variable Infiltration Capacity model successfully reproduced the present-day streamflow. The driven flows were identified highly correlated with the effectiveness of the downscaled precipitation. The future flows were projected to be markedly diverse, mainly due to the varied precipitation projections. Two of the three flow simulation runs projected slight to severe drying scenarios, while another projected an opposite trend for the evaluated future period.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3 Author(s): Megersa Olumana Dinka , Willibald Loiskandl , Julius Musyoka Ndambuki Study region The Matahara region is located in the East Showa zone of Oromiya regional state (Ethiopia). Matahra Sugar Estate and Lake Basaka (highly saline, alkaline and sodic lake) are situated within the flat plains of Matahara region. The area is vulnerable to the occurrences of various tectonic and volcanic activities due to its location in the upper most part of the Main Ethiopian Rift Valley region. Study focus In this study, the hydrochemical properties of different surface water and groundwater bodies available at Matahara region have been characterized for quality compositions. Water samples were collected from different water sources and analyzed for important major quality parameters following standard test procedures. Other chemical indices were derived from the measured quality parameters. The potential sources of minerals were suggested for each of the considered water sources based on their quality characteristics. New hydrological insights for the region Overall, the study result elucidates that the chemical composition of different water bodies are due to natural processes and/or anthropogenic activities within the region. The local anthropogenic processes could be discharges from factory, domestic sewage and farming activities. Some of the water types are found to have relatively higher concentration of dissolved constituents. Irrigation waters have almost equal chemical compositions, indicating their hydrochemical sources are almost the same. Most of the concentrations are relatively high in Lake Basaka, groundwater and hot springs. It is easy to imagine the potential damaging effects of such quality waters on crop production, soil properties and environment of the region.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3 Author(s): Julianne Hagarty , David Azanu , Bernadette Atosona , Ray Voegborlo , Erica A.H. Smithwick , Kamini Singha Study region Buruli ulcer, an emerging disease caused by Mycobacterium ulcerans , largely affects poor rural populations in tropical countries. The environmental niche that supports this necrotizing bacterium is unclear. Here, water samples were collected from five communities within Ghana in the rainy season in 2011: four in the southern part of Ghana (three disease-endemic communities: Pokukrom, Betenase, and Ayanfuri, and one control: Kedadwen) and one non-endemic community (Nangruma) in the north. Study focus Past studies of Buruli ulcer conclude that water quality is, in some way, closely related to the transmission of this disease. This work serves as a first step to explore links between Buruli ulcer incidence and water quality. More broadly, this research works toward identifying the environmental niche for M. ulcerans , providing characterization of water bodies hazardous to human health in at-risk communities. New hydrological insights Trace metals, thought to aid in the preferential growth of M. ulcerans , are present in higher concentrations in mining pits and stagnant pools than in other tested water bodies. Arsenic in particular could serve as a double threat for BU incidence: it could support the growth of M. ulcerans while suppressing immune systems, making the population more susceptible to disease. Few other differences between endemic and non-endemic communities exist, implying other variables such as human behavior may also control the onset of Buruli ulcer.

Description: Publication date: Available online 18 April 2015 Source: Journal of Hydrology: Regional Studies Author(s): Fabrice Papa , Frédéric Frappart , Yoann Malbeteau , Mohammad Shamsudduha , Venugopal Vuruputur , Muddu Sekhar , Guillaume Ramillien , Catherine Prigent , Filipe Aires , Rajesh Kumar Pandey , Sujit Bala , Stephane Calmant Study region The Ganges–Brahmaputra (GB), a major river basin of the Indian Sub-Continent (ISC), is the host of more than 700 millions people. Study focus In addition to monsoons and strong climate variability, GB is facing growing demands for freshwater availability by a continually growing population and rapidly developing of agricultural and industrial sectors. The management of water resources is thus of highest priority and, in the context of current over-abstraction of groundwater, accurate estimates of terrestrial freshwater storage are essential. We propose a multi-satellite approach to estimate surface freshwater storage (SWS) and subsurface water storage (SSWS, groundwater + soil moisture) variations over GB. New hydrological insights Basin-scale monthly SWS variations for the period 2003–2007 show a mean annual amplitude of ∼410 km 3 , contributing to about 45% of the Gravity Recovery And Climate Experiment (GRACE)-derived total water storage variations (TWS). During the drought-like conditions in 2006, we estimate that the SWS deficit over the entire GB basin in July–August–September was about 30% as compared to other years. The SWS variations are then used to decompose the GB GRACE-derived TWS and isolate the variations of SSWS whose mean annual amplitude is estimated to be ∼550 km 3 . This new dataset of water storage variations represent an unprecedented source of information for hydrological and climate modeling studies of the ISC.

Description: Publication date: Available online 7 April 2015 Source: Journal of Hydrology: Regional Studies Author(s): Swati Verma , Abhijit Mukherjee , Runti Choudhury , Chandan Mahanta Study region Brahmaputra River basin, India. Study focus The present study deciphers the groundwater solute chemistry and arsenic (As) enrichment in the shallow aquifers of the study region. Four different geomorphologic units, e.g. piedmont (PD), older alluvium of river Brahmaputra and its tributaries (OA), active alluvium of river Brahmaputra and its tributaries (YA) and river channel deposits (RCD) were identified. More than 62% of all groundwater samples collected have dissolved As >0.01 mg/L, whereas about 87% of groundwater samples in OA terrain are enriched with As, which draws a distinct difference from the adjoining Gangetic aquifers. New hydrological insights for the region Most groundwater solutes of RCD and YA terrains were derived from both silicate weathering and carbonate dissolution, while silicate weathering process dominates the solute contribution in OA groundwater. Groundwater samples from all terrains are postoxic with mean pe values between Fe(III) and As(V)–As(III) reductive transition. While, reductive dissolution of (Fe–Mn)OOH is the dominant mechanism of As mobilization in RCD and YA aquifers, As in OA and PD aquifers could be mobilized by combined effect of pH dependent sorption and competitive ion exchange. The present study focuses on the major ion chemistry as well as the chemistry of the redox sensitive solutes of the groundwater in different geomorphic settings and their links to arsenic mobilization in groundwater.

Description: Publication date: Available online 11 March 2015 Source: Journal of Hydrology: Regional Studies Author(s): B.M. Hallett , H.A. Dharmagunawardhane , S. Atal , E. Valsami-Jones , S. Ahmed , W.G. Burgess Study region The Maheshwaram and Waipally catchments of Andhra Pradesh, India, and the Plonnaruwa catchment of north-central Sri Lanka. Study focus The distribution of F across eight crystalline phases and between the bedrock and the regolith at eleven sites in three catchments is documented. Mineral contributions to F release during weathering and regolith development are quantified. New hydrological insights for the region An estimate of weathering duration for the in situ regolith in Andhra Pradesh, 250–380 Ka, is close to a previous estimate for southern India. Partial or total destruction of the primary F-bearing bedrock minerals and consistent depletion of F in the remnant minerals result in a much reduced total F content in the regolith. Leaching experiments and field relationships, however, indicate a greater potential for F mobilisation to groundwater from the regolith than the bedrock. Schemes for managed aquifer recharge should beware the risk of mobilising additional F to groundwater.

Description: Publication date: March 2015 Source: Journal of Hydrology: Regional Studies, Volume 3, Supplement 1 Author(s): Salah Er-Raki

Description: Publication date: Available online 10 December 2015 Source: Journal of Hydrology: Regional Studies Author(s): Tatsuya Utsunomiya, Masaki Hata, Ryo Sugimoto, Hisami Honda, Shiho Kobayashi, Yoji Miyata, Makoto Yamada, Osamu Tominaga, Jun Shoji, Makoto Taniguchi Study focus There have been far more studies on how the variability in surface water discharge affects production of animal communities in aquatic ecosystems while less information has been accumulated on the mechanisms of how the groundwater supply works. Study region Physical and biological surveys were conducted to test the hypothesis that high level of submarine ground water discharge enhances species richness, abundance and biomass of fishes and invertebrates in coastal waters of Obama Bay, Japan, where a high contribution of nutrients (ca. 65% of phosphorus) to total provided through all freshwater has been reported. Survey for horizontal distribution of radon-222 ( 222 Rn) concentration showed high levels of submarine groundwater discharge in the west part of survey area. Fish and invertebrate communities were compared within a relatively small spatial scale (ca. 100 m) in relation to level of submarine groundwater discharge. New hydrological insights Species richness, abundance and biomass of fishes and abundance and biomass of turban snail and hermit crab were significantly higher in the area with high 222 Rn concentration. Abundance of gammarids, the most major prey item of the fishes, was 18 times higher in the area with high 222 Rn concentration. Since the turban snail, hermit crab and gammarids feed on producers (phytoplankton and benthic microalgae), submarine groundwater are concluded to increase species richness and production of fishes and invertebrates through providing nutrients and enhancing primary production.

Description: Publication date: March 2016 Source: Journal of Hydrology: Regional Studies, Volume 5 Author(s): A.C. de la Casa, G.G. Ovando Study region Changes in reference evapotranspiration (ET o ) may have important consequences for agricultural suitability in the central region of Argentina. Annual ET o variation was assessed, in terms of both territory and time, for the 7 decades between 1941 and 2010, analyzing the behavior of the 4 atmospheric variables which determine it: temperature, vapor pressure, wind speed and cloud cover. Study focus The influence of each variable on ET o was evaluated from a multiple regression model and a simple correlation analysis, using climate data from the observation network, and repeating this analysis using interpolated variables. In this grid scheme, linear relationships were determined between ET o and the different key atmospheric variables, plus precipitation (PP), and the t test was applied to establish the statistically significant sectors ( P 〈 0.1). Then, those areas with a significant trend change ( P 〈 0.1) were determined by the Mann–Kendall test. Finally, the interception of the grids was performed to establish their joint occurrence. New hydrological insights for the region Most of the region analyzed (>91%) presents a non-significant variation of ET o over time, with a mostly non-significant change of each driving variable, regarding both its relationship with ET o and its own trend of change. The beneficial change in agricultural suitability reported for this water-limited region was found to be produced almost exclusively by increasing PP. Graphical abstract

Description: Publication date: Available online 11 December 2015 Source: Journal of Hydrology: Regional Studies Author(s): Makoto Taniguchi, Naoki Masuhara, Kimberly Burnett Security measures of three resources; water, energy and food are analyzed for thirty two countries in the Asia Pacific region which are faced to Pacific Ocean, in terms of amounts of the resource, self-production, and diversity of sources of each resource. Diversity for all the three resources is also analyzed using surface water and groundwater for water sources; hydro power, geothermal power, solar, and biomass for energy; and cereals, vegetable, fruit, meat, and fish for food. We see high diversity of sources of water in the US and the Philippines, and a low diversity of sources of food in the US, Canada, and Indonesia. These security measures including water security show new hydrological insight for Asia-Pacific region.

Description: Publication date: Available online 10 December 2015 Source: Journal of Hydrology: Regional Studies Author(s): Aiko Endo, Izumi Tsurita, Kimberly Burnett, Pedcris M. Orencio Study region Asia, Europe, Oceania, North America, South America, Middle East and Africa. Study focus The purpose of this paper is to review and analyze the water, energy, and food nexus and regions of study, nexus keywords and stakeholders in order to understand the current state of nexus research. New hydrological insights Through selected 37 projects, four types of nexus research were identified including water–food, water–energy–food, water–energy, and climate related. Among them, six projects (16%) had a close linkage with water–food, 11 (30%) with water–energy–food, 12 (32%) with water–energy, and eight (22%) with climate. The regions were divided into Asia, Europe, Oceania, North America, South America, Middle East and Africa. North America and Oceania had a tendency to focus on a specific nexus type, water–energy (46%) and climate (43%), while Africa had less focus on water–energy (7%). Regarding keywords, out of 37 nexus projects, 16 projects listed keywords in their articles. There were 84 keywords in total, which were categorized by the author team depending on its relevance to water, food, energy, climate, and combination of water–food–energy–climate, and 40 out of 84 keywords were linked with water and only 4 were linked with climate. As for stakeholders, 77 out of 137 organizations were related to research and only two organizations had a role in media.

Description: Publication date: March 2016 Source: Journal of Hydrology: Regional Studies, Volume 5 Author(s): Shilpa M. Asokan, Peter Rogberg, Arvid Bring, Jerker Jarsjö, Georgia Destouni Study region The large semi-arid Aral Region in Central Asia and the smaller tropical Mahanadi River Basin (MRB) in India. Study focus Few studies have so far evaluated the performance of the latest generation of global climate models on hydrological basin scales. We here investigate the performance and projections of the global climate models in the Coupled Model Intercomparison Project, Phase 5 (CMIP5) for freshwater fluxes and their changes in two regional hydrological basins, which are both irrigated but of different scale and with different climate. New hydrological insights for the region For precipitation in both regions, model accuracy relative to observations has remained the same or decreased in successive climate model generations until and including CMIP5. No single climate model out-performs other models across all key freshwater variables in any of the investigated basins. Scale effects are not evident from global model application directly to freshwater assessment for the two basins of widely different size. Overall, model results are less accurate and more uncertain for freshwater fluxes than for temperature, and particularly so for model-implied water storage changes. Also, the monsoon-driven runoff seasonality in MRB is not accurately reproduced. Model projections agree on evapotranspiration increase in both regions until the climatic period 2070–2099. This increase is fed by precipitation increase in MRB and by runoff water (thereby decreasing runoff) in the Aral Region.

Description: Publication date: March 2016 Source: Journal of Hydrology: Regional Studies, Volume 5 Author(s): Justin A. Schulte, Raymond G. Najjar, Ming Li Study region The Mid-Atlantic region of the United States. Study focus An understanding of past streamflow variability is necessary for developing future management practices that will help mitigate the impacts of extreme events such as drought or floods on agriculture and other human activities. To better understand mechanisms driving streamflow variability at all timescales, annual to multi-decadal streamflow variability of three major rivers in the Mid-Atlantic region of the United States (the Susquehanna, Delaware, and Hudson Rivers) was studied in the context of climate modes using correlation and wavelet analyses. New hydrological insights for the region Results from the correlation analysis detected statistically significant relationships between climate indices and streamflow that were similar for the three rivers. The results from the wavelet analysis showed that 18- and 26-year periodicities were embedded in the streamflow time series. Decadal variability of streamflow was coherent with the El-Niño Southern Oscillation (SO) and the Pacific Decadal Oscillation (PDO). The time series for the PDO and SO indices and precipitation were found to be synchronized to the decadal variability of a global circulation pattern consisting of a Rossby wave train emanating from the North Pacific. The SO explained 37–54% of the 1960s drought, 33–49% of the 1970s pluvial, and 19–50% of the 2000s pluvial in the three river basins.

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - General Subjects, Volume 1863, Issue 2〈/p〉 〈p〉Author(s): Mathilde Ménard, Florent Meyer, Ksenia Parkhomenko, Cédric Leuvrey, Grégory Francius, Sylvie Bégin-Colin, Damien Mertz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Human serum albumin (HSA) nanoparticles emerge as promising carriers for drug delivery. Among challenges, one important issue is the design of HSA nanoparticles with a low mean size of ca. 50 nm and having a high drug payload. The original strategy developed here is to use sacrificial mesoporous nanosilica templates having a diameter close to 30 nm to drive the protein nanocapsule formation. This new approach ensures first an efficient high drug loading (ca. 30%) of Doxorubicin (DOX) in the porous silica by functionalizing silica with an aminosiloxane layer and then allows the one-step adsorption and the physical cross-linking of HSA by modifying the silica surface with isobutyramide (IBAM) groups. After silica template removal, homogenous DOX-loaded HSA nanocapsules (30–60 nm size) with high drug loading capacity (ca. 88%) are thus formed. Such nanocapsules are shown efficient in multicellular tumor spheroid models (MCTS) of human hepatocarcinoma cells by their significant growth inhibition with respect to controls. Such a new synthesis approach paves the way toward new protein based nanocarriers for drug delivery.〈/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-S0304416518303416-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Volume 1866, Issue 1〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Comptes Rendus Geoscience, Volume 350, Issue 7〈/p〉 〈p〉Author(s): Ilias Fountoulakis, Christos S. Zerefos, Alkiviadis F. Bais, John Kapsomenakis, Maria-Elissavet Koukouli, Nozomu Ohkawara, Vitali Fioletov, Hugo De Backer, Kaisa Lakkala, Tomi Karppinen, Ann R. Webb〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Spectral UV records of solar irradiance at stations over Europe, Canada, and Japan were used to study long-term trends at 307.5 nm for a 25-year period, from 1992 to 2016. Ground-based measurements of total ozone, as well as satellite measurements of the Aerosol Index, the Total Cloud Cover and the surface reflectivity were also used in order to attribute the estimated changes of the UV to the corresponding changes of these factors. The present study shows that over the Northern Hemisphere, the long-term changes in UV-B radiation reaching the Earth's surface vary significantly over different locations, and that the main drivers of these variations are changes in aerosols and total ozone. At high latitudes, part of the observed changes may also be attributed to changes in the surface reflectivity. Over Japan, the UV-B irradiance at 307.5 nm has increased significantly by ∼3%/decade during the past 25 years, possibly due to the corresponding significant decrease of its absorption by aerosols. It was found that the greatest part of this increase took place before the mid-2000s. The only European station, over which UV radiation increases significantly, is that of Thessaloniki, Greece. Analysis of the clear-sky irradiance for the particular station shows increasing irradiance at 307.5 nm by ∼3.5%/decade during the entire period of study, with an increasing rate of change during the last decade, possibly again due to the decreasing absorption by aerosols.〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Drug Resistance Updates, Volume 41〈/p〉 〈p〉Author(s): Mohammad Hamidian, Ruth M. Hall〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In multiply resistant 〈em〉Acinetobacter baumannii,〈/em〉 complex transposons located in the chromosomal 〈em〉comM〈/em〉 gene carry antibiotic and heavy metal resistance determinants. For one type, known collectively as AbaR, the ancestral form, AbaR0, entered a member of global clone 1 (GC1) in the mid 1970s and continued to evolve 〈em〉in situ〈/em〉 forming many variants. In AbaR0, antibiotic and mercuric ion resistance genes are located between copies of a cadmium-zinc resistance transposon, Tn〈em〉6018,〈/em〉 and this composite transposon is in a class III transposon, Tn〈em〉6019〈/em〉, carrying arsenate/arsenite resistance genes and five 〈em〉tni〈/em〉 transposition genes. The antibiotic resistance genes in the AbaR0 and derived AbaR3 configurations are 〈em〉aphA1b〈/em〉, 〈em〉bla〈/em〉〈sub〉TEM〈/sub〉, 〈em〉catA1〈/em〉, 〈em〉sul1, tetA〈/em〉(A), and cassette-associated 〈em〉aacC1〈/em〉 and 〈em〉aadA1〈/em〉 genes. These genes are in a specific arrangement of fragments from well-known transposons, e.g. Tn〈em〉1〈/em〉, Tn〈em〉1721,〈/em〉 Tn〈em〉1696〈/em〉 and Tn〈em〉2670〈/em〉, that arose in an IncM1 plasmid. All known GC1 lineage 1 isolates carry AbaR0 or AbaR3, which arose around 1990, or a variant derived from one of them. Variants arose via deletions caused by one of three internal IS〈em〉26〈/em〉s, by recombination between duplicate copies of 〈em〉sul1〈/em〉 or Tn〈em〉6018,〈/em〉 or by gene cassette addition or replacement. A few GC2 isolates also carry an AbaR island with different cassette-associated genes, 〈em〉aacA4〈/em〉 and 〈em〉oxa20〈/em〉.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 173〈/p〉 〈p〉Author(s): Yixiang Zhang, Jianming He, Xiao Li, Chong Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydraulic fracturing using freshwater as fracturing fluid is regularly employed in commercial shale gas or oil production. Many problems are brought by the fracturing fluid of water, such as water shortages, swelling of clay mineral, and the pollution of flow-back water. Replacement of water by supercritical CO〈sub〉2〈/sub〉 (SC〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉CO〈sub〉2〈/sub〉) in the hydraulic fracturing treatment of shale reservoir has meaningful potential for the improvement of gas production. Hydraulic fracturing experiments, under different injection rate and stress state, were carried out for studying the SC-CO〈sub〉2〈/sub〉 fracturing of shale considering anisotropy effects. Anisotropy of shale has a significant impact on the mechanical behavior and fracture propagation of shale in the experiment. There shows a downward tendency for breakdown pressure with the increase of bedding plane angle in general. Higher injection rate can lead to the higher breakdown pressure, while higher deviator stress can lead to the lower breakdown pressure instead. In addition, three patterns of fracture propagation can be observed in the experiment, relative to the bedding structures of shale specimen, including propagating along, propagating across and arresting. The maximum values of fracture width during experiment in shale with different bedding plane angle ranges from 0.29 mm to 1.05 mm, while the final fracture width after the fracturing experiment is kept within the range of 0.01 mm–0.04 mm under the injection rate of 0.3 ml/s.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 173〈/p〉 〈p〉Author(s): Xueying Wang, Hongjian Ni, Ruihe Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Toolface control is an important issue when drilling directional wells with steerable motors. In this paper, a new experimental apparatus has been built to study the toolface behavior while slide drilling. In experiments, weight on bit and toolface orientation during the simulated slide drilling are recorded and analyzed. Experimental results indicate that axial stick-slip motion of the drillstring that occurs in the presence of large friction causes toolface disorientation. In addition, the phenomenon of toolface hysteresis in horizontal wells is identified. The asymmetric loading and unloading rates of weight on bit result in toolface hysteresis, and toolface hysteresis worsens toolface disorientation. A new method of correcting toolface by quickly eliminating toolface hysteresis is proposed. Four torque-related parameters are used in the method, and each has a specific implication. The proposed method has been examined using the experimental apparatus and has been proven to work. The experimental results and related analysis in this paper can help to further improve the efficiency of toolface control during slide drilling.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 365〈/p〉 〈p〉Author(s): Per Morten Hansen, André Vagner Gaathaug, Dag Bjerketvedt, Knut Vaagsaether〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study discusses the rapid expansion and phase transition of liquefied carbon dioxide (CO〈sub〉2〈/sub〉) in vertical ducts. Results from small-scale experiments in three test setups (A, B, and C) were compared with a Rankine-Hugoniot model that treats the phase transition as an adiabatic evaporation wave of constant thickness. The model calculates the fluid properties behind the evaporation wave. The motivation was to identify hazards and quantify the energy-release in tank explosions such as a boiling liquid expanding vapor explosion. The experimental results corresponded with a Chapman Jouguet (CJ) solution. The contributions include a mapping of CJ solutions calculated from a range of pre-rupture conditions. The puncture of a diaphragm (setup A, and B), or complete test section rupture (setup C) initiated the tests. The three test setups provided a range of pressures for the model. Evaporation waves were observed, propagating with velocities of 35–42 ms〈sup〉−1〈/sup〉 (setup A, and B), and ∼ 10 ms〈sup〉−1〈/sup〉 (setup C) into the superheated liquid. The calculated vapor mass fraction behind of the evaporation wave was in the range 0.21-0.23. The study presents a strategy, which incorporates the calculated vapor mass fraction, to predict the energy released in a tank explosion.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 365〈/p〉 〈p〉Author(s): Esther Gomez-Herrero, Montserrat Tobajas, Alicia Polo, Juan J. Rodriguez, Angel F. Mohedano〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we assessed the potential of combining Fenton´s reagent and biological oxidation for removing the imidazolium-based ionic liquid 1-Ethyl-3-methylimidazolium chloride (EmimCl). Fenton-like oxidation was conducted at variable H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 doses from 20 to 100% the stoichiometric value as calculated from the theoretical chemical oxygen demand (COD). The stoichiometric H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 dose afforded Total Organic Carbon (TOC) conversion and COD removal of 50 and 62%, respectively. Identifying the reaction by-products formed at low hydrogen peroxide doses allowed a plausible pathway for EmimCl oxidation to be proposed. The effluents from Fenton-like oxidation at substoichiometric H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 doses were less ecotoxic and more biodegradable than was the parent ionic liquid. The effluent from Fenton-like oxidation with the 60% H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 dose (TOC conversion ≅ 41%, COD removal ≅ 31%) was subsequently subjected to an effective biological treatment that allowed complete removal of the starting compound, increased its ecotoxicity to a low–moderate level and rendered it acceptably biodegradable. Biological oxidation was performed in 8-h and 12-h cycles in a sequencing batch reactor. Combining Fenton and biological oxidation of EmimCl afforded TOC conversion and COD removal of around 90%.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941831015X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 364〈/p〉 〈p〉Author(s): Zhiyong Liu, Shu Zhang, Dan Hu, Yunsheng Zhang, Henglin Lv, Cheng Liu, Yidong Chen, Juan Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, paraffin/red mud phase change energy storage composites were fabricated at 4 mix proportions with paraffin to red mud ratios of 0.4:0.6, 0.45:0.55, 0.5:0.5, and 0.55:0.45 by a mixed mill-heating method. Scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) results reveal that paraffin flows well into red mud pores and has good compatibility. The differential scanning calorimetry (DSC) results reveal that the melting temperatures of the paraffin/red mud phase change energy storage composite vary from 75℃ to 85℃, and the latent heat value is approximately 25–40J/g. High thermal stability is observed by the thermogravimetric analysis (TG) method. The Brunauer Emmett Teller (BET) isotherms, laser particle sizer, X-ray diffraction analysis (XRD), and laser Raman spectrograph (LRS) show that the phase change energy storage composite does not produce a new material from the raw materials and that the material has a stable performance. Furthermore, the paraffin/red mud phase change energy storage composite was incorporated into the cement-based and gypsum-based materials at 10%, 20%, and 30% weight. The heat storage performance can be improved remarkably with an increase in the addition of phase change energy storage composite replacement. The compressive strength change is minimal with the addition of 10% and 20%, and the compressive strength decreases by nearly 40% with the addition of 30%. The paraffin/red mud phase change energy storage composite has a large influence on the flexural strength.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 364〈/p〉 〈p〉Author(s): Muhammad Humayun, Zhewen Hu, Abbas Khan, Wei Cheng, Yang Yuan, Zhiping Zheng, Qiuyun Fu, Wei Luo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we report for the first time the highly efficient degradation of 2,4-dichlorophenol (2,4-DCP) over CeO〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composites (xCeO/CN) prepared via wet-chemical solution method. It is shown that the resultant nanocomposites with a proper mass ratio percentage (15%) of CeO coupled exhibit greatly enhanced visible-light activity for 2,4-dichlorophenol (2,4-DCP) degradation compared to the bare g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. From photoluminescence (PL) and Fluorescence (FL) results, it is suggested that enhanced photo-degradation is attributed to the significantly improved charge separation and transfer as a result of the proper band alignments between g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and CeO components. Further, from radical trapping experiments, it is confirmed that hydroxyl radicals (〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH) are the predominant oxidants involved in the degradation of 2,4-DCP over CeO/CN composites. Furthermore, a possible reaction pathway and detailed photocatalytic mechanism for 2,4-DCP degradation is proposed mainly based on the detected liquid chromatography tandem mass spectrometry (LC–MS) intermediate products, that readily transform into CO〈sub〉2〈/sub〉 and H〈sub〉2〈/sub〉O. This work would help researchers to deeply understand the reaction mechanism of 2,4-DCP and would provide feasible routes to fabricate g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉-based highly efficient photocatalysts for environmental remediation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389418310069-ga1.jpg" width="264" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 365〈/p〉 〈p〉Author(s): Lei Yang, Lu Xu, Xue Bai, Pengkang Jin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a novel TiO〈sub〉2-x〈/sub〉/rGO-PS-Vis process was developed, which utilizes the TiO〈sub〉2-x〈/sub〉/rGO (Ti〈sup〉3+〈/sup〉 and oxygen vacancies self-doped TiO〈sub〉2〈/sub〉 coupled with reduced graphene oxide) nanocomposite as a promising and efficient activator of persulfate (PS) for the enhanced oxidation of micropollutants under visible -light irradiation. TiO〈sub〉2-x〈/sub〉/rGO exhibited a significantly high activity for PS activation to produce more sulfate radicals (SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉) and hydroxyl radicals (〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH). Therefore, almost 100% BPA (10 mg/L) and 80% TOC can be removed just within 12 min with 1.0 g/L TiO〈sub〉2-x〈/sub〉/rGO and 2 mM PS under visible light. Moreover, it was found that many other typical micropollutants, such as phenol, acetaminophen and sulfamethoxazole can also be effectively degraded by this process. Electron paramagnetic resonance (EPR) and radical quenching experiments indicated that both SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉 and 〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH contribute to the degradation of organics, and the radical process was the main degradation pathway. In addition, the effects of PS concentration, catalyst dosage, initial solution pH and inorganic anions were investigated systematically. Experiments carried out in the real background of water matrix with low-concentration of BPA indicated that the proposed TiO〈sub〉2-x〈/sub〉/rGO-PS-Vis process has strong non-selective photo-oxidative ability for the removal of micropollutants in water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389418310082-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change, Volume 138〈/p〉 〈p〉Author(s): Jae-Woong Min, Nicholas S. Vonortas, YoungJun Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study explores the factors that contribute to the commercialization of technologies transferred from universities and public research institutes (U&PRIs) to companies. We take a step further than the established literature focusing on technology transfer to examine factors that also affect the chances of the successful commercialization of the transferred technologies through an empirical analysis of 669 technology transfer cases in Korea. The study shows that the intensity of market competition is a key factor in moderating the effects of partnership and absorptive capacity on the successful commercialization of transferred technologies. While collaboration with U&PRIs exerts a positive effect on commercialization success, this effect is weakened by the intensity of market competition. The intensity of market competition boosts the importance of company absorptive capacity for the commercialization success of the transferred technology. We conclude that strategic management of the absorptive capacities of companies and their partnership with U&PRIs are necessary ingredients of the success of technology transfer in concordance with the intensity of competition that the company faces in the market.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): Saheed Bukola, Stephen E. Creager〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Transmission rates for protons and deuterons across single-layer graphene embedded in Nafion | graphene | Nafion sandwich structures are measured as a function of temperature in electrochemical hydrogen pump cells. Rates of ion transmission through graphene are obtained in the form of area-normalized ion-transfer resistances, and are interpreted in terms of ion-exchange current densities and standard heterogeneous ion-transfer rate constants. An encounter pre-equilibrium model for the ion-transfer step is then used to provide rate constants for the fundamental microscopic step of ion (proton or deuteron) transmission across graphene. Application of this rate model to interpret variable-temperature data on proton and deuteron transmission rates provides values for the activation energy and pre-exponential factor for the fundamental ion transmission step across graphene. Activation energies obtained from the Arrhenius plots for proton and deuteron transmission are as follows; for proton, E〈sub〉act〈/sub〉 = 48 ± 2 kJ/mole (0.50 ± 0.02 eV) and for deuteron, E〈sub〉act〈/sub〉 = 53 ± 5 kJ/mole (0.55 ± 0.05 eV). The difference between these two values of approximately 5 kJ/mole is in good agreement with the expected difference in vibrational zero-point energies for O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H and O-D bonds, albeit with some uncertainty given the uncertainties in the activation energy values. Pre-exponential frequency factor values of 8.3 ± 0.4 × 10〈sup〉13〈/sup〉 s〈sup〉−1〈/sup〉 and is 4.7 ± 0.5 × 10〈sup〉13〈/sup〉 s〈sup〉−1〈/sup〉 were obtained for proton and deuteron transmission respectively across graphene. These pre-factor values are both quite large, on the order of the values predicted from the Eyring – Polanyi equation with a transmission coefficient near one. The ratio of 1.8 for the rate pre-factors (H/D) is in reasonable agreement with the value of 1.3 for the ratio of bond vibrational frequencies for O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H and O-D stretching, respectively. Taken together, these data support a model in which proton and deuteron transmission across graphene are largely adiabatic processes for which the differences in transmission rate at room temperature are due largely to differences in activation energies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 143〈/p〉 〈p〉Author(s): Yi Ren, Fang Cheng, Xiaoying Zhou, Kai Chang, Guanghui Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two-dimensional (2D) polyaniline with C〈sub〉3〈/sub〉N stoichiometry, is a newly fabricated layered material that has been expected to possess fascinating electronic, thermal, mechanical and chemical properties. The nature of its counterpart nanoribbons offering even more tunability in properties because of the unique quantum confinement and edge effect, however, has not been revealed yet. Here we systemically study the mechanical, electronic and magnetic properties for various nanoribbons cutting from a monolayer C〈sub〉3〈/sub〉N sheet along the typical crystallographic orientations. By the first-principles calculations we find that C〈sub〉3〈/sub〉N nanoribbons exhibit sensitive responses to the externally applied electric field and strain. Specifically, the spin-selective half-metallicity depends on the external electric field or strain, as well as the ribbon width. For the asymmetric zigzag-edged ribbon, the spin-polarization rate approaches −100% at electric field strength −0.2 V/Å. Interestingly, an applied strain can transform a symmetric zigzag-carbon-edge ribbon from a magnetic semiconductor to a half-metal. And the half-metal property remains unchanged when the strain increases from 8 to 15%, while the spin-up subband gap further increases to 0.46 eV. These numerical results may be useful to engineer and design magnetic-field-free spintronic devices based on the 2D C〈sub〉3〈/sub〉N.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318309333-fx1.jpg" width="256" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 142〈/p〉 〈p〉Author(s): Sivabrata Sahu, Mihir Ranjan Sahoo, Anoop Kumar Kushwaha, G.C. Rout, S.K. Nayak〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have investigated here, the electronic and magnetic properties of graphene–nickel system by tight-binding mean-field approach. Strong hybridization between the 2p〈sub〉z〈/sub〉 orbital of graphene and 3d〈sub〉z2〈/sub〉 orbital of nickel occurs when monolayer graphene is placed over a single layer of ferromagnetically ordered Ni (111) metal due to the excellent lattice matching between the two layers. This hybridization greatly affects the electronic and magnetic properties of the bilayer system, resulting in a significantly reduced local magnetic moment of the nickel layer and an enhanced induced spin polarization on the graphene layer. The calculated Hamiltonian revealed critical information regarding the first-, second-and third-nearest-neighbour hopping integrals of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mi〉π〈/mi〉〈mo〉−〈/mo〉〈/mrow〉〈/math〉 electrons of graphene besides the Coulomb correlation of electrons in nickel (111). The Hubbard type Coulomb interactions present in nickel lattices were treated within the mean-field approximation. Zubarev's technique was employed to calculate electronic Green's functions and subsequent investigation of the temperature dependent ferromagnetic magnetization of nickel (111)was carried out through self-consistent calculation. Further calculations regarding the induced magnetization in the graphene, total magnetization in bilayer layer system, electronic band dispersion, spin resolved density of states (DOS) and spin polarization efficiency have been carried out. The results were corroborated by experimental observations.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318309977-egi10LZ69G4T53.jpg" width="283" alt="Image" title="Image"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 143〈/p〉 〈p〉Author(s): Lihua Lin, Hongzhe Pan, Yanhuan Chen, Xiaoying Song, Jun Xu, Huibiao Liu, Shaolong Tang, Youwei Du, Nujiang Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pristine graphdiyne (pGDY) with high quality was prepared by annealing as-prepared GDY in hydrogen, and its stacking style, bandgap and magnetism were studied. The results show that pGDY is ABC-stacked, has a direct bandgap of ca. 0.64 eV, and shows spin-half paramagnetism at 2 K which may result from the residual hydroxyl groups on the chains of GDY sheet. The hybrid functional calculations show that ABC-stacked GDY is a semiconductor with a direct bandgap of 0.73 eV and is intrinsically nonmagnetic.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318309126-fx1.jpg" width="350" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 143〈/p〉 〈p〉Author(s): A. Yadav, M. Yadav, S. Gupta, Y. Popat, A. Gangan, B. Chakraborty, L.M. Ramaniah, R. Fernandes, A. Miotello, M.R. Press, N. Patel〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reduced graphene oxide (rGO)〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉TiO〈sub〉2〈/sub〉 composites are prepared using photo-reduction method by varying GO to TiO〈sub〉2〈/sub〉 weight ratio from low (rGOT-0.001, 0.01, & 0.1) to high (rGOT-1, 3 & 10) range and its effect on morphological, optical and mechanism of fast charge dynamics at the interface are investigated. Experimental analysis confirm that reduction process improves as TiO〈sub〉2〈/sub〉 amount increases in rGO-TiO〈sub〉2〈/sub〉 but leads to aggregation of TiO〈sub〉2〈/sub〉 nanoparticles. rGOT-3 composite displayed the highest photocatalytic activity for degradation of phenols compared to TiO〈sub〉2〈/sub〉, GO and other composites. This was achieved due to uniform dispersion of TiO〈sub〉2〈/sub〉 nanoparticles over rGO surface, which enables distinct formation of Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C bond between each TiO〈sub〉2〈/sub〉 nanoparticle and rGO surface, and results in slight red shift in the band edge. This Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C bond facilitates fast electron transfer from TiO〈sub〉2〈/sub〉 to rGO and reduces recombination rate as revealed by photoluminescence and time resolved photoluminescence spectroscopy. The experimental findings were further investigated using density functional theory simulations. Band structure calculation confirms high mobility states induced within the band gap due to formation of Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C bond in rGO-TiO〈sub〉2〈/sub〉 model which assists in fast electron transfer from TiO〈sub〉2〈/sub〉 to rGO during the photocatalytic process and hence reduces recombination rate.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318310091-fx1.jpg" width="477" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 143〈/p〉 〈p〉Author(s): Rebecca F. Albers, Rafael A. Bini, João B. Souza, Derik T. Machado, Laudemir C. Varanda〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉There is great interest in new materials that synergistically combine properties of reduced graphene oxide (rGO) with nanoparticles (NP) generating rGO-nanoparticles hybrid materials (NPHM). Based on the modified polyol process (MPP), we developed a new and versatile method to synthesize rGO and rGO-NPHM in one-pot route. rGO sheets with small defects number were reduced from graphene oxide by the MPP, and experimental parameters were varied to evaluate the method robustness, and adjusted to prepare rGO-NPHM, for instance, rGO/Au, rGO/Ag, rGO/CdSe, rGO/FePt and rGO/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 inferring the versatility of our methodology. NPHM were evaluated by X-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, and Raman, UV–Vis, and FTIR spectroscopies. All synthesized NPHM shown size-controlled monodisperse-like NP homogeneously distributed onto the rGO sheets, except for the Ag-NP where a bimodal size distribution was observed. Plasmon (rGO/Au and rGO/Ag) and typical absorption and emission (rGO/CdSe) by UV–Vis, whereas paramagnetic-like (rGO/FePt) and superparamagnetic (rGO/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉) behavior was observed by the magnetic NPHM. The MPP is already efficient for NP preparation and here, we showed that its might successful for rGO and rGO-NPHM synthesis in a simple and versatile one-pot route, which can be scaled up to allow mass production and easily tuned for other NP kinds.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318310066-fx1.jpg" width="404" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 142〈/p〉 〈p〉Author(s): Yaochen Song, Jiaxuan Liao, Cheng Chen, Jian Yang, Jinchen Chen, Feng Gong, Sizhe Wang, Ziqiang Xu, Mengqiang Wu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Self-assembled nano-honeycomb WS〈sub〉2〈/sub〉 modified by graphene doping were prepared by improved one step hydrothermal method. In this hybrid structure, graphene plays a key role of transferring the morphology from the nanowire microporous spheres to graphene-supported nano-honeycomb plane structure, which has the larger the specific surface area and higher conductivity. This anode delivers the superb electrochemical performances of lithium/sodium ion batteries with high specific charge capacity (953.1/522.3 mAh·g〈sup〉−1〈/sup〉 at 0.1 A·g〈sup〉−1〈/sup〉), long cycling life (more than 350/200 cycles at 1 A·g〈sup〉−1〈/sup〉), and high charge/discharge rates (up to 10/5 A·g〈sup〉−1〈/sup〉). This nano-honeycomb structure WS〈sub〉2〈/sub〉 composite anode with facile hydrothermal process, as well as superb electrochemical performances, makes it attractive for the potential applications in lithium/sodium ion batteries.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318307103-fx1.jpg" width="299" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 143〈/p〉 〈p〉Author(s): Ll.M. Evans, L. Margetts, P.D. Lee, C.A.M. Butler, E. Surrey〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Functional materials' properties are influenced by microstructures which can be changed during manufacturing. A technique is presented which digitises graphite foam via X-ray tomography and converts it into image-based models to determine properties in silico. By simulating a laser flash analysis its effective thermal conductivity is predicted. Results show ∼1% error in the direction the foam was ‘grown’ during manufacturing but is significantly less accurate in plane due to effective thermal conductivity resulting from both the foam's microstructure and graphite's crystalline structure. An empirical relationship is found linking these by using a law of mixtures. A case study is presented demonstrating the technique's use to simulate a heat exchanger component containing graphite foam with micro-scale accuracy using literature material properties for solid graphite. Compared against conventional finite element modelling there is no requirement to firstly experimentally measure the foam's effective bulk properties. Additionally, improved local accuracy is achieved due to exact location of contact between the foam and other parts of the component. This capability will be of interest in design and manufacture of components using graphite materials. The software used was developed by the authors and is open source for others to undertake similar studies.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318309461-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 143〈/p〉 〈p〉Author(s): Ke Chu, Jing Wang, Ya-ping Liu, Yuan-bo Li, Cheng-chang Jia, Hu Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In-situ formation of appropriate interfacial carbides by matrix-alloying with carbide-forming elements offers an efficient approach to improve the interfacial bonding of graphene/CuX composites. However, the carbide formation commonly occurs at graphene edge/matrix interface, which is not enough to achieve the sufficient interfacial bonding because the vast majority of graphene/matrix interface is basal-plane/matrix interface rather than edge/matrix interface. To alleviate this limitation, we reported a new design of 〈em〉creating defects on graphene basal-plane〈/em〉 (CDGB) to optimize the interface and mechanical properties of graphene/CuCr composites. Plasma treatment was employed to create the structural defects (∼7 nm nanopores) on graphene basal-plane. When incorporating the plasma-treated graphene into the CuCr matrix, the Cr〈sub〉7〈/sub〉C〈sub〉3〈/sub〉 carbides were found to be in-situ formed at both basal-plane/matrix and edge/matrix interfaces. Ex-situ and in-situ tensile tests both demonstrated that the plasma-treated graphene led to the composite that showed a larger strength enhancement and a higher load transfer capability than untreated counterpart, which was ascribed to the largely improved interfacial bonding contributed by the Cr〈sub〉7〈/sub〉C〈sub〉3〈/sub〉 formed at basal-plane/matrix interface. This study suggests that the CDBG via plasma treatment affords a feasible solution for the interface optimization of graphene/CuX composites with enhanced mechanical properties.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318310145-fx1.jpg" width="477" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 142〈/p〉 〈p〉Author(s): Dalsu Choi, Hyun-Sig Kil, Sungho Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently restricted greenhouse gas emission regulations for commercial vehicles have initiated a significant interest of an automotive industry in carbon fibers (CFs), which are excellent lightweight structural materials. However, the high production cost of CFs has limited their use in a selected number of applications including military, aircraft, and aerospace industries. Therefore, to satisfy a huge demand from the automotive industry and to translate an exotic technology into commercial applications, tremendous research efforts have focused on developing low-cost CFs. As the precursor cost takes more than 50% of an entire cost for CFs production, adopting low-cost precursors for CFs have been utilized as one of the main strategies. In this article, we review series of previous achievements which incorporated low-cost precursors into CFs fabrication including novel acrylic polymers, polyethylene (PE), lignin, and pitch. Furthermore, looking toward the future, prospective processing technologies which might be beneficial for reducing manufacturing cost of CFs are also reviewed.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318309436-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 17 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon〈/p〉 〈p〉Author(s): Paolo Restuccia, M.C. Righi〈/p〉

Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 European Polymer Journal〈/p〉 〈p〉Author(s): Ali Behnood, Mahsa Modiri Gharehveran〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Asphalt binders play an integral role in the performance and properties of asphalt mixtures. Increased traffic-related factors on the roadways such as heavier loads, higher traffic volume, and higher tire pressure combined with substantial variation in daily and seasonal temperatures of the pavement have been responsible for the asphalt pavements failure. To prevent or mitigate these failures, many attempts have been made by polymer scientists and civil engineers to improve the performance of asphalt pavements by modifying the properties of asphalt binders. A good modifier changes the failure properties such that binder yields more stresses and strains before failure. Modification of asphalt binders through the addition of a polymer to improve their rheological and physical properties has a long history in asphalt industry. Once the polymer is properly mixed with the asphalt binder, a swallowed polymer network is formed, which contributes to the changes in viscoelastic behavior. However, polymer-modified asphalt binders may have some drawbacks related to the poor solubility of polymers. Understanding the internal structure of polymer-modified asphalt binders has been the subject of numerous research studies.〈/p〉 〈p〉Available studies regarding the affecting parameters on the properties of the polymer-modified asphalt binders are reviewed here. Various types of polymers used in asphalt industry and their effects on the rheological, morphological, physical and mechanical properties of polymer-modified asphalt binders are also discussed in this paper. In addition, this paper provides a review on the techniques used to overcome/mitigate the shortcomings of conventional polymer-modified asphalt binders.〈/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-S0014305718318019-ga1.jpg" width="341" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ocean & Coastal Management, Volume 167〈/p〉 〈p〉Author(s): Uxío Labarta, M〈sup〉a〈/sup〉 José Fernández-Reiriz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The mussels industry with a production that accounts for more than twenty five percent of the fresh product landings from the sea, and the full-time employment of more than 8000 people, is by far the largest productive activity of the Galician sea.〈/p〉 〈p〉In the 1980s was noticed an increase in productivity related to processes of innovation in the industry of mussel. Together with it, the first organizational forms of the Galician-based production sector was constituted, with a spatial and administrative reordering for mussel rafts and crops. A new reality of the sector was maintained in both the marketing guidelines and the fact of initiating a vertical integration between the mussel industry and the commercialization. Everything was accompanied by changes in markets and strong tensions: derived from red tides that limit the operating cycle and even its profitability and also from the conflicts between the producing and transforming organizations, added to the competition in the markets of other countries, mainly Chile.〈/p〉 〈p〉The reality of mussel culture and markets leads to a reformulation in the industry, with strategies for territorial diversification of suppliers, new technological improvements in production and even organizational, economic, and bioecological innovations.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Kaili Jin, Man Zhou, Hong Zhao, Shixiong Zhai, Fengyan Ge, Yaping Zhao, Zaisheng Cai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the large theoretical capacity and environmental benignity, copper sulfide (CuS) becomes a prospective candidate electrode material for supercapacitors. In this work, electroconductive mesoporous carbonized clothes (Cc) was obtained by carbonizing the waste cotton fabrics. Then the CuS was galvanostatic electrodeposited on 〈em〉Cc〈/em〉 to prepare the binder-free 〈em〉g〈/em〉-CuS/Cc electrode. In the galvanostatic electrodeposition process, CuS grew along the crystal surface to form regular nanosheets, and a part of Cu〈sup〉2+〈/sup〉 were reduced to Cu〈sup〉1.1+〈/sup〉. In addition, on account of the synergistic effect of electrochemical double layer capacitance with pseudocapacitance and the high specific surface area (450.76 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉), the 〈em〉g〈/em〉-CuS/Cc composite displayed not only outstanding areal specific capacitance (4676 mF cm〈sup〉−2〈/sup〉 at 2 mA cm〈sup〉−2〈/sup〉) but also excellent cycling performance (89.8% retention after 10000 cycles). Meanwhile, the symmetrical flexible supercapacitor (SC) based on 〈em〉g〈/em〉-CuS/Cc electrodes with PVA-KOH gel electrolyte (〈em〉g〈/em〉-CuS/Cc-SC) accomplished a high specific capacitance of 1333 mF cm〈sup〉−2〈/sup〉 at 2 mA cm〈sup〉−2〈/sup〉 as well as ultrahigh energy density of 0.96 Wh cm〈sup〉−2〈/sup〉 at the power density of 4.36 W cm〈sup〉−2〈/sup〉. Therefore, 〈em〉g〈/em〉-CuS/Cc shows a great potential for applications in the next generation of flexible energy storage devices.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618324447-fx1.jpg" width="384" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Kang Li, Zhanwei Xu, Xuetao Shen, Kai Yao, Jianshe Zhao, Ronglan Zhang, Jun Zhang, Li Wang, Jianfeng Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Commercial lithium/thionyl chloride (Li/SOCl〈sub〉2〈/sub〉) batteries cannot meet the 3.15 V platform required for most instruments. A 〈em〉hovenia acerba〈/em〉-like assembly constructed with cobalt tetrapyridinoporphyrazine of thickness of 5–15 nm is anchored on acid-functionalized multi-walled carbon nanotubes (CoTAP/MWCNTs), which were prepared using an 〈em〉in situ〈/em〉 solid synthesis process. The discharge time of Li/SOCl〈sub〉2〈/sub〉 batteries with a voltage greater than 3.15 V catalyzed by CoTAP/MWCNTs is found to be 11 min longer than batteries without catalysts and 4 min longer than those catalyzed by CoTAP alone. The energy of Li/SOCl〈sub〉2〈/sub〉 batteries with a voltage greater than 3.15 V catalyzed by CoTAP/MWCNTs is discovered to be 11.44-times higher than batteries with AF-MWCNTs and 6.17-times higher than those catalyzed by bulk CoTAP. This is due to the fact that more CoTAP ultrafine nanoparticulates are anchored on the AF-MWCNTs. These nanoparticulates provide more active sites for the catalytic reaction of SOCl〈sub〉2〈/sub〉. The assemblies are shown to have an adsorption-coordination effect on Li ions and to delay the deposition of lithium chloride passive films enhancing battery voltage platforms.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉A 〈em〉hovenia acerba〈/em〉-like assembly constructed with cobalt tetrapyridinoporphyrazine of thickness of 5–15 nm is anchored on acid-functionalized multi-walled carbon nanotubes (CoTAP/MWCNTs), which were prepared using an 〈em〉in situ〈/em〉 solid synthesis process. The discharge time of Li/SOCl〈sub〉2〈/sub〉 batteries with a voltage greater than 3.15 V catalyzed by CoTAP/MWCNTs is found to be 11 min longer than batteries without catalysts and 4 min longer than those catalyzed by CoTAP alone.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618324319-fx1.jpg" width="270" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry Letters, Volume 28, Issues 23–24〈/p〉 〈p〉Author(s): J.S. Dileep Kumar, Francesca Zanderigo, Jaya Prabhakaran, Harry Rubin-Falcone, Ramin V. Parsey, J. John. Mann〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Overexpression of Cyclooxygenase-2 (COX-2) enzyme is associated with the pathogenesis of inflammation, cancers, stroke, arthritis, and neurological disorders. Because of the involvement of COX-2 in these diseases, quantification of COX-2 expression using Positron Emission Tomography (PET) may be a biological marker for early diagnosis, monitoring of disease progression, and an indicator of effective treatment. At present there is no target-specific or validated PET tracer available for in vivo quantification of COX-2. The objective of this study is to evaluate [〈sup〉11〈/sup〉C]TMI, a selective COX-2 inhibitor (Ki ≤ 1 nM) in nonhuman primates using PET imaging. PET imaging in baboons showed that [〈sup〉11〈/sup〉C]TMI penetrates the blood brain barrier (BBB) and accumulates in brain in a somewhat heterogeneous pattern. Metabolite analyses indicated that [〈sup〉11〈/sup〉C]TMI undergoes no significant metabolism of parent tracer in the plasma for baseline scans, however a relative faster metabolism was found for blocking scan. All the tested quantification approaches provide comparable tracer total distribution volume (V〈sub〉T〈/sub〉) estimates in the range of 3.2–7 (mL/cm〈sup〉3〈/sup〉). We observed about 25% lower V〈sub〉T〈/sub〉 values in blocking studies with meloxicam, a nonselective COX-2 inhibitor, compared to baseline [〈sup〉11〈/sup〉C]TMI binding. Our findings indicate that [〈sup〉11〈/sup〉C]TMI may be a suitable PET tracer for the quantification of COX-2 in vivo. Further experiments are needed to confirm the potential of this tracer in COX-2 overexpressing models for brain diseases.〈/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-S0960894X18308515-ga1.jpg" width="487" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 142〈/p〉 〈p〉Author(s): Baoyin Jin, Ding-Bang Xiong, Zhanqiu Tan, Genlian Fan, Qiang Guo, Yishi Su, Zhiqiang Li, Di Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Corrosion protection of metals is of great importance due to their widespread use. Graphene (Gr) has shown promising corrosion resistance as a coating for metals, however, its excellent strengthening effect that has been widely shown is suppressed in such coating applications. Here, inspired by positive anti-corrosion role of graphene coating for metal macro-foils, graphene encapsulated Cu (Cu@Gr) micro-/nano-flakes are designed and fabricated, and then used as building blocks for assembling bulk Gr/Cu composites. Thanks to its protective role and strengthening effect of uniformly dispersed graphene in Cu matrix, as compared to bare copper, corrosion rate of the as-fabricated bulk Gr/Cu composites is reduced by 50% in NaCl solution and its yield strength is increased by ∼180% (2.5 vol% Gr) simultaneously, without deterioration on electrical conductivity. The anti-corrosion mechanisms are understood by studying etching behavior of the Cu@Gr flakes in FeCl〈sub〉3〈/sub〉 solution, and surface morphology evolution in the samples subjected to salt spray corrosion, and electrochemical corrosion tests. Graphene's anti-corrosion effect is also reflected by an anisotropic corrosion behavior of the Gr/Cu composite because of a “brick-and-mortar” microstructure. The results presented here shed light on expanding metal matrix composite's applications to a wider range and more complex situation by incorporating graphene.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622318310078-fx1.jpg" width="239" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Transport Geography, Volume 73〈/p〉 〈p〉Author(s): Chengxi Liu, Yusak O. Susilo, Dimas B.E. Dharmowijoyo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The activity space of an individual is defined as the activity-travel environment which a traveller is using for his or her activities (Axhausen et al., 2002). It is limited by this individual's ability and resources, such as available time for travel as well as his or her anchor points. However, most existing studies have focused on single individual activity space, ignoring the fact that individuals' activities often interact with that of his or her family members'. In this paper a multivariate model is proposed where the correlation between travel time of fathers and mothers, and the correlation between the activity space and travel time are modelled explicitly. The estimated correlations from these joint distributions provide insights into both the intra-household interactions in daily travel and the intrinsic relationships of the hidden limits in the dimensions of space and time. The travel time limits are modelled using a stochastic frontier model component, which can estimate an unobserved upper or lower limit for travel time expenditure. This limit usually refers to the maximum travel time budget or minimum travel time need, which denotes the maximum or minimum amount of travel time that an individual is willing or able to allocate per day. The concept of the confidence ellipse is used as a measure of activity space constructed from the multi-day travel diary data. It is hypothesised that the unobserved travel time limits and activity space sizes of fathers and mothers are correlated with each other, due to a similar spatial knowledge and accessibility to various facilities. The daily variations in the travel time expenditure of parents are also assumed to be correlated because of daily household task allocation and joint household travel. Data collected from a three-week household travel diary in the Bandung Metropolitan Area in Indonesia are used for estimation in this study. The estimated frontier model component shows that neither parent has reached their maximum travel time budget and/or minimum travel time need that they inherently must spend. Compared with other attributes, the perceived accessibility attributes play the most important role in influencing the activity space limits. For households with fully employed fathers, a trade-off mechanism is found in travel time expenditure between parents, which is likely due to the redistribution of household tasks. On the other hand, for households with fathers who are not fully employed, a complementary effect is found, arising from the joint travel among household members. The travel time budget and activity space limits of fathers are positively correlated with those of mothers. These findings call for the formulation of transport policies that consider the household as a unit, especially in developing countries such as Indonesia, to fulfil the mobility needs of different market segments, e.g., households with fully employed fathers and those with fathers who are not fully employed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Physics and Chemistry of Solids, Volume 124〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis A: General, Volume 570〈/p〉 〈p〉Author(s): Wooyoung Kim, Wookyun Shin, Kyoung Jun Lee, YongSeok Cho, Hyung Soon Kim, Igor N. Filimonov〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Characterization of acid-base centers and catalytic dehydration of 2,3-butanediol (BDO) was performed over a wide range of silica-supported alkali phosphates (M_P/SiO〈sub〉2〈/sub〉; M = Na, K, Cs; M:P = 0.5–3 mol:mol). Selectivity to 1,3-butadiene (BD) and 3-butene-2-ol (3B2OL) formed by elimination correlates with the densities of conjugated acid-base pairs and increases in the order Na 〈 K ≈ Cs. Selectivity to 2,3-epoxybutane (BTO) formed by dehydrative epoxidation increases with the M/P ratio in the order Na 〈 K ≤ Cs. Methyl ethyl ketone (MEK) and isobutyraldyde (IBA) formed by the rearrangement are produced by isolated Brønsted acid centers. Conjugated acid-base pairs are probably composed of the end groups of polyphosphates having both acid P-OH and base P〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈sup〉−〈/sup〉⋯M〈sup〉+〈/sup〉 moieties. Isolated Brønsted acid centers are probably silica grafted phosphoric acid molecules at low M/P and 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉PO(OH)〈sub〉2〈/sub〉 end groups of oligophosphates at M/P 〉 1.5.〈/p〉 〈p〉Deactivation rate increases with the increase of M/P ratio in order Na 〈 K 〈 Cs. Deactivation patterns imply that sites responsible for elimination are active in dehydrative epoxidation. Dehydration of 3B2OL smoothly proceeds to BD, but the catalysts deactivate faster compared to BDO dehydration.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926860X18304095-ga1.jpg" width="491" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid State Sciences, Volume 85〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid State Sciences, Volume 85〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid State Sciences, Volume 85〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 29 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Tetrahedron, Volume 74, Issue 48〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Phytochemistry, Volume 157〈/p〉 〈p〉Author(s): XingRong Peng, Lei Li, JinRun Dong, ShuangYang Lu, Jing Lu, XiaoNian Li, Lin Zhou, MingHua Qiu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Twelve previously undescribed lanostane-type triterpenoids, including three triterpenoids with a 〈em〉γ〈/em〉-lactone ring, namely applanlactones A‒C, four highly oxygenated lanostane triterpenoids, namely methyl applaniate A and applanoic acids B‒D, as well as five C21 nortriterpenoids, applanones A‒E were isolated from the fruiting bodies of 〈em〉Ganoderma applanatum〈/em〉 (Pers.) Pat.〈em〉.〈/em〉 Their structures were elucidated by 1D, 2D NMR and MS spectra, as well as X-ray crystallographic analyses. Meanwhile, applanlactone A, methyl applaniate A and applanoic acid B showed inhibitory effects for the proliferation of hepatic stellate cells (HSCs) induced by transforming growth factor-〈em〉β〈/em〉1 (TGF-〈em〉β〈/em〉1) 〈em〉in vitro〈/em〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Three polyoxygenated lanostane triterpenoids isolated from the fruiting bodies of 〈em〉Ganoderma applanatum〈/em〉 showed anti-liver fibrosis activities.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0031942218303352-fx1.jpg" width="369" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Catalysis, Volume 368〈/p〉 〈p〉Author(s): Michiel Janssen, Lisa Van Emelen, Carlos Marquez, Trees De Baerdemaeker, Dirk E. De Vos〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Selective functionalization of hydrocarbons remains one of the most challenging reactions in organic chemistry. With respect to terminal C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H hydroxylation, electrophilic activation by late transition metals has been considered a promising route. We report the use of Shilov-chemistry inspired Pt catalysis in acetic acid as suitable solvent for the formation of primary alcohols from long linear alkanes. By reacting 〈em〉n〈/em〉-heptane with K〈sub〉2〈/sub〉PtCl〈sub〉4〈/sub〉 under an oxygen atmosphere, a positional selectivity of 18% was reached for 1-heptanol among the C〈sub〉7〈/sub〉 alcohols at significantly high conversion (37%). Moreover, we provide evidence for the intrinsic activity of Pt(II), along with elucidation of the role of specific additives as coordinating ligands. Both acetic anhydride (AA), initially added as protecting agent, and sulfuric acid proved to be essential to obtain an active alkane hydroxylation system; via ESI-MS [Pt(AA)(OSO〈sub〉3〈/sub〉H)〈sub〉3〈/sub〉(H〈sub〉2〈/sub〉O)]〈sup〉+〈/sup〉 and [Pt(CH〈sub〉3〈/sub〉COOH)(OSO〈sub〉3〈/sub〉H)〈sub〉3〈/sub〉(H〈sub〉2〈/sub〉O)]〈sup〉+〈/sup〉 were identified in the active catalytic system. Furthermore, nonselective overoxidation originates from various side reactions, for which a reaction network is proposed. Finally, the stability of the 〈em〉in situ〈/em〉 formed esters was studied in detail by recording time-dependent profiles for the decomposition of different positional isomers of 〈em〉n〈/em〉-octyl acetate, as well as of its fluorinated analogues. Altogether, these results illustrate the clear potential of the proposed concept in forming primary alcohols directly from cheap and abundant alkanes.〈/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-S0021951718304044-ga1.jpg" width="369" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Catalysis, Volume 368〈/p〉 〈p〉Author(s): Andrea Jouve, Gergely Nagy, Ferenc Somodi, Cristina Tiozzo, Alberto Villa, Antonella Balerna, Andrea Beck, Claudio Evangelisti, Laura Prati〈/p〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021951718304032-ga1.jpg" width="379" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Catalysis, Volume 368〈/p〉 〈p〉Author(s): Gennady I. Panov, Mikhail V. Parfenov, Eugeny V. Starokon, Alexandr S. Kharitonov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Investigation of reaction mechanisms by identifying the intermediates released into the gas phase is most effective at low conversion of reactants, ideally approaching zero. However, conversions below 0.5–1% are rarely used, due to the difficulty of analysis of low-concentration products. The mechanism of the title reaction is a subject of long-term discussion. We studied the mechanism using an original ultralow conversion (ULC) method. The idea is to perform the analysis of products after their preliminary accumulation in a suitable absorbent at the reactor outlet. This allows decreasing conversion by 2–3 orders of magnitude. The ULC experiments were conducted with a Bi–Mo catalyst at 100–250 °C and with propene conversion down to 0.001%. A new so-called allyl hydroxylation mechanism was revealed. A key step is the hydroxylation of the CH〈sub〉3〈/sub〉 group to form an allyl alcohol intermediate, which is further oxidized to acrolein. The mechanism explains all reaction features and was confirmed by experiments at 350 °C.〈/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-S0021951718303804-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Chromatography B, Volume 1105〈/p〉 〈p〉Author(s): Jesper Sundell, Emile Bienvenu, Sofia Birgersson, Angela Äbelö, Michael Ashton, Kurt-Jürgen Hoffmann〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Co-infection of tuberculosis in HIV-patients is a major health concern worldwide and especially so in Sub-Saharan Africa. To enhance the study of potential drug-drug interactions when simultaneously treating the two infections, a liquid chromatography tandem mass spectrometry method was developed for the quantitation of the four first line anti-tuberculosis drugs isoniazid, rifampicin, pyrazinamide, ethambutol and four of their major metabolites in human plasma.〈/p〉 〈p〉Analytes were extracted from 200 μL of plasma using a sequential liquid-liquid extraction with ethyl acetate at neutral and acidic pH. The combined extracts were analyzed by liquid chromatography with mass spectrometric detection in a multiple reaction monitoring mode. The chromatographic separation was performed on a hydrophilic interaction column using a stepwise gradient with two mobile phases consisting of water with 0.3% formic acid and methanol with 0.3% formic acid, respectively. The total run time of each analysis was 4 min. The lower limit of quantification applied was 40 ng/mL for ethambutol, acetylisoniazid and 25-desacetylrifampicin, 60 ng/mL for 5-hydroxypyrazinamide, 80 ng/mL for isoniazid and isonicotinic acid, 200 ng/mL for rifampicin and 320 ng/mL for pyrazinamide. The method was validated according to US Food and Drug Administration guidance. The method exhibited adequate accuracy (87.1–114.9%), precision (CV 〈 12.8%) and specificity. Recovery and matrix effect were consistent (CV 〈 11.9%). The extracted samples were stable in the autosampler at 8 °C for up to 24 h as well as after three freeze-thaw cycles (recovery 〉 86.3%). The method has been shown to be robust for the analysis of the stated drugs and metabolites in human plasma obtained from 73 patients receiving these four first line anti-tuberculosis drugs.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment, Volume 220〈/p〉 〈p〉Author(s): Xiyu Chen, Lin Liu, Annett Bartsch〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microwave remote sensing, both active or passive, can provide useful information about the freeze/thaw (F/T) state of soil near the surface. Here we apply an edge detection algorithm on time series of indicators derived from measurements of SMAP L-band radiometer and ASCAT C-band scatterometer to detect the freeze/thaw onsets of surface soil. Comparing these results against the onsets derived from in situ measurements in Alaska, we demonstrate that this algorithm is an effective approach to detect onsets of the soil F/T transition. More specifically, our results show that the thawing onsets estimated from the SMAP data occurred 5 to 13 days earlier than the onsets estimated from the in situ measurements, which is likely due to the influence of snowmelt on the radiometer signal. The thawing onsets estimated from the ASCAT data were about 6 days later than the in situ onsets. Our estimated freezing onsets from each microwave remote sensing dataset were close to the in situ onsets (1–5 days). We also compare our estimated onsets with those from the SMAP Level 3 F/T product and the mean biases for thawing and freezing onsets are 1 ± 2 and 1 ± 3 days, respectively. Furthermore, we illustrate the complementary nature of the SMAP and ASCAT measurements and the potential for combining these two to differentiate snowmelt from soil thawing events.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment, Volume 220〈/p〉 〈p〉Author(s): Mathilde Cancet, David Griffin, Madeleine Cahill, Bertrand Chapron, Johnny Johannessen, Craig Donlon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Australia's marginal seas include a wide range of ocean current regimes ranging from tide-dominated in the North-West where the continental shelf is wide, to boundary current- and eddy-dominated in the South-East, where the shelf is narrow. Here, we take the opportunity to test the GlobCurrent surface ocean current products against in-situ observations in these two contrasting regimes. Observations by Acoustic Doppler Current Profiler (ADCP) instruments of Australia's Integrated Marine Observing System (IMOS) and drifting buoys of the Global Drifting Programme (GDP) are used.〈/p〉 〈p〉The monthly-timescale variability of the GlobCurrent alongshore current component is in moderately good agreement with the observations on the continental shelf in the South-East but neither the shorter period variability nor the long-term mean are representative of the ADCP observations. While the observed tidal currents are negligibly small, the wind-driven signals are not. But these are evidently too transient to be adequately sampled by altimetry. The inclusion of an Ekman component does not represent these signals because the interaction of the Ekman transport with the coastal boundary condition is not included. Similarly, the error of the time-mean velocity, which is the dominant error, is because that product is not designed to represent the highly anisotropic nature of the sea level gradients over the continental shelf nor the constraints on the flow field that are imposed by the topography. We thus conclude that the GlobCurrent product needs improvements before it can be described as very suitable for applications on this, and probably other, narrow continental shelf. Off the continental shelf, in contrast, the GlobCurrent products compare quite well with the trajectories of drifting buoys, confirming that the products are quite suitable for blue-water applications.〈/p〉 〈p〉In contrast to the South-East, the tides are very strong in the North-West region of Australia. The sub-tidal variability is weak, in both relative and absolute senses. Consequently, the removal of the tidal signal from the sea level observations needs to be very complete for the residual error to be smaller than the true sub-tidal signal. Transient wind forced signals are also occasionally large so this step of the de-aliasing also needs to be very accurate. Unfortunately, it appears that more work is required before accurate estimates of sub-tidal variability are available from GlobCurrent: the magnitude of the GlobCurrent estimates of sub-tidal current variability far exceed the magnitude of, and are uncorrelated with, the detided ADCP data.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Organic Geochemistry, Volume 125〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Geochemistry, Volume 99〈/p〉 〈p〉Author(s): M. Lanzoni, W.G. Darling, W.M. Edmunds〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Like many dryland regions around the world, the Butana Region of Sudan is almost entirely dependent on groundwater, and its main source of recharge comes from the highly variable 150–200 mm/yr rain that arrives mostly during a three-month rainy season. These rains cause ephemeral wadis to flow and flood, and provide a critical component of shallow aquifer replenishment.〈/p〉 〈p〉This study uses water table fluctuations along a 20 km wadi reach and chemical and stable isotopic tracers in 27 shallow (〈40 m) and 6 deep (70–170 m) wells to show differences between mean recharge in the alluvial aquifer, estimated as 38–105 mm/yr, and the basal Nubian sandstone aquifer unit at 13–36 mm/yr. This study suggests while groundwater from the Nubian sandstone is predominantly palaeowater of −8 to −6‰ δ〈sup〉18〈/sup〉O formed during a wetter, early-Holocene climate, modern recharge does reach the Nubian sandstone aquifer unit in areas 〈0.3 km from the wadi. An upstream dam may also focus this wadi-directed recharge.〈/p〉 〈p〉In the 1980s, conjunctive use of major and trace geochemistry, isotope, and physical hydrology in the study of wadi recharge was only beginning to gain traction as a sub-discipline, and the study of Edmunds et al. (1987) in the Abu Delaig area paved the way for hydrogeochemical studies in unmonitored dryland catchments around the world. Thirty years on from that study, the local population has grown tenfold, water extraction has increased to accommodate mining, and an upstream dam has been built. This study, conducted in a 400 km〈sup〉2〈/sup〉 subset of the original Lower Atbara Basin study, answers a previously unanswered question about wadi recharge to the deeper, Nubian sandstone aquifer unit and offers a unique three-decade perspective on groundwater development in a rural, arid environment expanding beyond its margin of groundwater sustainability.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 30 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): Sonal Choudhary, Rakesh Nayak, Sushma Kumari, Homagni Choudhury〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Drawing on theories of acculturation and information diffusion, this paper examines whether social media usage, intergroup contacts and information dissemination influence the cultural adaptation of three ethnic groups, and its implications on sustainable consumption behaviour. Twenty-four semi-structured interviews containing multiple dimensions of social media uses, acculturation, food consumption behaviour, and information diffusion were administered to a sample of Indians (living in the home country), British Indians (living in the host country for more than 10 years) and White British (natives of Britain) users of social media. Our findings suggest that there is a clear link between the integrated strategy of acculturation and information diffusion on social media, which influences acculturation to sustainable food consumption behaviour among social media users. Managerial implications of this research finding are that intervention in information diffusion aids acculturation through the social media, which serves to infuse social media and sustainability strategist with knowledge to best influence the consumers in developing sustainable food consumption behaviour. This research also identifies opportunities to expand this academic research and contribute further to the theories of remote acculturation on which limited research has been done.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Gang Yuan, Xiao Zhao, Yeru Liang, Lin Peng, Hanwu Dong, Yong Xiao, Chaofan Hu, Hang Hu, Yingliang Liu, Mingtao Zheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a new class of zero-dimensional carbon nanomaterials, carbon dots have triggered intensive research interest in various fields. However, the low surface area, hydrophilicity, and agglomeration characteristics limit their applications in energy storage fields. Herein, we demonstrate that nitrogen-doped carbon dots can be employed as efficient nanoenhancer to boost the electrochemical performance of three-dimensional graphene. The as-prepared materials exhibit an interconnected framework with abundant oxygen- and nitrogen-containing functional groups, which enable fast penetration and transport of electrolyte ions and provide more active sites and electric conductivity. Employed as binder-free electrode for supercapacitors, the resultant materials present high specific capacitance (338 F g〈sup〉−1〈/sup〉) and areal capacitance (604 μF cm〈sup〉−2〈/sup〉) at a current density of 0.5 A g〈sup〉−1〈/sup〉, which is much higher than that of pristine three-dimensional graphene (190 F g〈sup〉−1〈/sup〉, and 114 μF cm〈sup〉−2〈/sup〉), with an enhancement of 78% and 430%, respectively. Moreover, superior long-term cycling stability (94% of capacitance retention after 20 000 charging/discharging cycles at 10 A g〈sup〉−1〈/sup〉) as well as improved electric conductivity can also be achieved. These results certify that nitrogen-doped carbon dots can be applied as nanobooster to comprehensively improve the performance of graphene for high-performance electrochemical energy storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Small nitrogen-doped carbon dots (〈em〉N〈/em〉-CDs) are employed as efficient nanoenhancer to significantly boost the electrochemical performances of three-dimensional graphene (3DG) for supercapacitors.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312931-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Yuanyuan Zhang, Lili Wang, Fengying Dong, Qiao Chen, Haiyan Jiang, Mei Xu, Jinsheng Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉-based ternary composite materials are generally synthesized by two- or multi-step method and special precursor of CO〈sub〉3〈/sub〉〈sup〉2−〈/sup〉 is usually utilized in synthesis of Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉, which are time-consuming, laborious and relatively costly. In this paper, for the first time, a facile one-step solvothermal method is used to fabricate Z-scheme Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉/Bi/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 ternary composites. Interestingly, ethylene glycol not only acts as solvent for the reaction system, but also reduced Bi〈sup〉3+〈/sup〉 into metallic Bi and itself is oxidized to CO〈sub〉3〈/sub〉〈sup〉2−〈/sup〉, which could construct Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉. On this occasion, Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉/Bi/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 ternary composites are obtained after one-step method. High resolution transmission electron microscopy clearly reveals each component in composites. The as-prepared samples could be applied in various photocatalytic activities. Under solar light irradiation, Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉/Bi/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 composites exhibited prominent photodegradation performances for both ciprofloxacin and bisphenol A. Meanwhile, these composites could also be used in efficient photoreduction of CO〈sub〉2〈/sub〉. The efficient photocatalytic activity could be mainly ascribed to Z-scheme electron transfer mechanism in ternary composites, which is determined by surface redox reactions, active species trapping experiment, electron spin resonance spectrum.〈/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-S0021979718312918-ga1.jpg" width="425" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Hua Guo, Ya Su, Yanling Shen, Yumei Long, Weifeng Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Optimizing heterostructure of nanocomposites holds great potential for making full use of their ability. Herein, gold nanoparticles (AuNPs) were in situ synthesized over the surface of graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) via one-step pyrolyzation route using a single source precursor. The precursor of melamine chloroauric (C〈sub〉3〈/sub〉H〈sub〉6〈/sub〉N〈sub〉6〈/sub〉H〈sup〉+〈/sup〉⋅AuCl〈sub〉4〈/sub〉〈sup〉−〈/sup〉) was obtained through chemical precipitation reaction between melamine and chloroauric acid. The morphological analysis confirmed the compact contact between Au nanoparticles and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Then, the Au-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanocomposites were employed to fabricate electrochemical sensor by modifying glassy carbon electrode (GCE). Electrochemical experiments showed that the Au-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 exhibited enhanced electrocatalytic activity towards tetracycline oxidation as compared with either pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 or Au nanoparticles. Based on cyclic voltammetry (CV) method, the sensor was applied in the detection of tetracycline with a low detection limit of 0.03 μM (S/N = 3) and the linear range of concentration were 0.1–20 μM and 20–200 μM, respectively. Moreover, such an electrochemical sensor demonstrated high stability and good selectivity. Finally, the electrochemical sensor was applied to drug assays and exhibited sufficient precision and accuracy. Therefore, this work paves a new way of preparing g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉–based heterostructures and provides an efficient method for the detection of tetracycline in clinical analysis and quality control.〈/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-S0021979718313018-ga1.jpg" width="419" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Mingmei Zhang, Hong Liu, Ying Wang, Tianjiao Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three-dimensional (3D) flower center/petal nanostructure exhibits excellent electrochemical performance because of their unique unfold ultra-thin multi-layer structure benefit to the rapid transmission of electrons and the full infiltration of the electrolyte. A three-phase Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 nanosflower is constructed by one step alcohothermal technique using a mixture solvent of glycerol, diethylene glycol and ethylenediamine. Ethylenediamine successfully functions as the complexing agent of metal ions to slowly release the metal ions in the process of reaction, which encourage the flower petal nanostructure formation. Interestingly, when the proportion of iron increased, a novel Fe〈sub〉7〈/sub〉S〈sub〉8〈/sub〉@Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 flower center/petal nanostructure come into being. Benefiting from the interconnected structure of the multi-layer shell, the Fe〈sub〉7〈/sub〉S〈sub〉8〈/sub〉@ Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 nanosflower displays high specific capacitance of 670.4C g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉, excellent rate capability of 79.2% (531.0C g〈sup〉−1〈/sup〉 at 20 A g〈sup〉−1〈/sup〉), and longer cycling stability of 92.1% retained capacitance after 5000 cycles. Furthermore, the assembled hybrid supercapacitor demonstrates high energy density of 49.9 Wh kg〈sup〉−1〈/sup〉 at power density of 770.0 W kg〈sup〉−1〈/sup〉. Our results provide a new strategy to design metal sulfides with special structure for application to asymmetrical supercapacitor cathode material.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A three-phase core/shell flower-like Fe〈sub〉7〈/sub〉S〈sub〉8〈/sub〉@Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 is successfully constructed by one step alcohothermal technique using a mixture solvent of glycerol, diethylene glycol and ethylenediamine. The as-obtained composites become a promising electrode material for the next generation energy storage devices with high specific capacitance (670.4C g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉), excellent energy density (49.9 Wh kg〈sup〉−1〈/sup〉 at power density of 770.0 W kg〈sup〉−1〈/sup〉), as well as good long-term cycling stability (almost 88.9% retention after 10,000 cycles).〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312906-ga1.jpg" width="496" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 562〈/p〉 〈p〉Author(s): Parisa Moazzam, Giorgio Luciano, Amir Razmjou, Ehsan Akbari, Pavel G. Ul’yanov, Soumitro Mahanty〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The degree of available energy on a surface determines how a surface interacts with its surrounding environment such as corrosion. Current approaches to protection of Aluminum surfaces from corrosion mainly focus on adding an organic or inorganic layer to either act as a barrier from oxidant or scarifying to inhibit the corrosion. Altering the surface energy of Al on a molecular level is another alternative approach to efficiently modify the Al surface without the need for another thick expensive protective or scarifying materials. Herein, an attempt was made to understand how a molecular scale energy alteration improves the anticorrosion behavior of an aluminum surface. Two different surface engineering alteration strategies have been discussed; termed ALOSH and ALTSH modification. A variety of analytical instruments, i.e., FTIR, EDAX, XPS, SEM, AFM, WCA, and SFE measurement were used to systematically characterize the samples. Electrochemical impedance spectroscopy revealed that there are different resistances after the surface modifications. The trapping air resistance appeared in ALTSH is approximately 2.4 and 36 times higher than that of ALOSH and bare samples, respectively. The potentiostat analysis results showed that the mili inch per year value of coating for ALTSH was 0.012 while that of ALOSH was 0.507. It was also found that the low surface energy alteration without using inert molecules is not enough to render corrosion inhibition property, as it needs to have a protective energy barrier with no or minimal active electrochemical behavior.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311294-ga1.jpg" width="320" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Tetrahedron, Volume 74, Issue 51〈/p〉 〈p〉Author(s): Xiang Li, Feng Zhang, Dan Wu, Yirui Liu, Gan Xu, Yanli Peng, Zixiong Liu, Yuxin Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A highly efficient, green and sustainable protocol for rhodium(III)-catalyzed C-H alkylation of heterocycles with allylic alcohols has been achieved, which affords a series of β-aryl ketones in high yields. The reaction proceeds smoothly in water under air, and works well with heterocycles such as indoles, indolines, pyrroles and carbazoles. Notably, the expensive rhodium catalyst in water could be easily separated from the organic products, and reused for at least five times without loss of its catalytic activity and selectivity, which is a promising, green and sustainable pathway for the synthesis of β-aryl ketones. To the best of our knowledge, this is the first example for the reuse of expensive rhodium catalyst in water.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0040402018313115-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 364〈/p〉 〈p〉Author(s): Shanshan Sun, Haizhen Wang, Yuanzhi Chen, Jun Lou, Laosheng Wu, Jianming Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Mycobacterium〈/em〉 sp. WY10 was a highly effective PAHs-degrading bacterium that can degrade phenanthrene (PHE, 100 mg L〈sup〉−1〈/sup〉) completely within 60 h and 83% of pyrene (PYR, 50 mg L〈sup〉-1〈/sup〉) in 72 h. In this study, ten and eleven metabolites, respectively, were identified in PHE and PYR degradation cultures, and a detailed PHE and PYR metabolism maps were constructed based on the metabolic results. The strain WY10 degraded PHE and PYR with initial dioxygenation mainly on 3,4- and 4,5-carbon positions, respectively. Thereafter, PYR degradation entered the PHE degradation pathway via the 〈em〉ortho〈/em〉-cleavage. It was observed that the “lower pathway” of PHE and PYR degradations were different. Based on the kinetics of residual metabolites, PHE was degraded in a dominant phthalate pathway and a minor salicylate pathway. However, both phthalate and salicylate pathways played important roles on PYR degradation. The WY10 genome revealed there were fifty-three genes related to PAHs degradations, including a complete gene set for PHE and PYR degradation via the phthalate pathway. The candidate gene/ORF, BOH72_19755, encoding salicylate synthase might contribute in the salicylate pathway.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389418309737-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): E.A. Zakharova, I.N. Krylenko, A.V. Kouraev〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Due to the rapid decline of 〈em〉in situ〈/em〉 observations on river discharge in Arctic regions, evaluation of the continental freshwater input to the Arctic Ocean has become problematic and necessitates the development of alternative approaches based on remote sensing. Radar altimetric satellites have demonstrated high potential for estimation of river water discharge. Compared to polar orbiting altimeters, non-polar orbit satellites have an advantage in temporal sampling. Their greatest drawback, however, is spatial coverage: observations do not cover the low reaches of most parts of Arctic rivers. In this study of the Lena River, we demonstrate a way to overcome this limitation by using a combination of 〈em〉in situ〈/em〉 observations from tributaries and satellite observations in the middle river reaches. The water discharge as well as monthly and annual water flow were evaluated using three virtual stations. Direct combination of the water level from these virtual stations was not possible because of the difference in seasonal amplitude. However, the combination of altimetric discharge from the three independently processed tracks significantly improves the flow retrievals. The accuracy of the monthly water flow estimates at the river outlet is 23%. It increases with the integration time giving 7% for annual flow.〈/p〉〈/div〉 〈/div〉