ALBERT

Description: Publication date: Available online 22 March 2016 Source: Dendrochronologia Author(s): Alexander Gradel, Christina Hänsch, Batsaikhan Ganbaatar, Batdorj Dovdondemberel, Ochirragchaa Nadaldorj, Björn Günther The mountain forest steppe and taiga in northern Mongolia have experienced a forest decline in area and quality since the end of the last century. Changes in land use, climate, fire frequency and pest occurrence are considered to be the main drivers of this vegetation shift and desertification. Because this region is the source for major rivers, is home to a unique flora and fauna and represents an important source of timber for Mongolia, the ability of different tree species to respond to these changes and regenerate is of increasing interest. Our contribution focuses on the climate-growth relationship of old and young birch trees from two valleys in the Mongolian province of Selenge Aimag. The research site Bugant, located in the Western Khentey Mountains, was the most important logging centre in Mongolia during socialist times. Today, the vegetation is dominated by succession forests of light taiga. The research site Altansumber, on the border of the Sant and Khushat soum, is dominated by light taiga and mountain forest steppe. Traditional nomads who depend on these forests for different reasons inhabit this area. Wood cores were sampled and chronologies of young and old birch trees at Bugant and Altansumber were created. Climate data were obtained from the Eroo station, which is known in the region for its long and reliable climate record. We analysed the climate-growth relationships of the chronologies from 1962 to 2009. At both sites and in both age classes, correlations with temperature were predominantly negative, particularly in April (Bugant, south- and east-facing slopes) and May (Altansumber, north-facing slopes). Precipitation of the late summer of the previous year (August/September) positively correlated with the growth of birch at Altansumber. We assume that the significant negative correlation between winter precipitation (December/January) and the growth of old birches at both sites is due to positive effects of snow cover on the survival rate of herbivorous insect populations. Our results indicate that during the early vegetation period, younger birch trees are more dependent on water availability than older ones. Negative pointer years were characterized by below-average precipitation during the current summer period and above-average spring temperatures. For the old trees, positive pointer years were characterized by above-average summer precipitation. We conclude that water availability is the most crucial factor for the growth of white birch in northern Mongolia.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Luke J. Amos-Binks, David A. MacLean We used dendrochronological analyses to identify periods of natural disturbance and resulting growth responses in 32 mixed species stands in the Acadian forest. Stands represented five different development patterns, based upon 1946 softwood (SW) content (70–80%, termed SW versus 30–60%, termed mixedwood (MW)) and change in SW content from 1946 to 2006: SW-stable, SW-declining, MW-fluctuating, MW-stable, and MW-declining. Standardized growth chronologies were developed from 1163 increment cores sampled from balsam fir ( Abies balsamea ), red spruce ( Picea rubens ), yellow birch ( Betula alleghaniensis ), and sugar maple ( Acer saccharum ). Growth chronologies clearly identified three spruce budworm ( Choristoneura fumiferana ) outbreaks from 1914 to 1921, 1954 to 1961, and 1975 to 1984, and birch dieback from 1938 to 1948. Stand developmental patterns were caused by species characteristics and multiple interacting disturbances, resulting in mortality, growth reductions, releases, and establishment of new cohorts. Balsam fir was present in all stands, but its tendency to establish and release from advanced regeneration following budworm-caused mortality resulted in cyclical proportions of fir in the canopy. Red spruce was less vulnerable to spruce budworm and longer lived, allowing them to persist and better withstand disturbance. Periodic growth index values less than 0.9 for fir and spruce were correlated with mortality of softwoods caused by defoliation, which resulted in release and growth index values >1.1 for sugar maple. Our results demonstrated substantial variation in mixedwood development patterns over a 60-year period within a small (45 km) area.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Terje Thun, Helene Svarva Nineteen Norwegian grain chests made of Scots pine ( Pinus sylvestris L.) were analyzed by measuring tree-ring widths on photographs and scanned pictures. Seventeen of the chests were successfully dated by dendrochronology. Two of the dates are corrections of an earlier dating; the ages of these two chests were verified by radiocarbon dating. The grain chests were expected to be medieval, but four, all without carvings, proved to be post-medieval. The mean curve constructed from the dated chests matches all regional Scots pine chronologies in central and southern Norway and several from southern Sweden. All the chests were probably constructed in central Norway. Originally only sixteen chests were known, but several new ones were discovered in the course of this project.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Marcelo Pablo Chartier, María Alejandra Giantomasi, Daniel Renison, Fidel Alejandro Roig Soil erosion is a serious problem of land degradation in many parts of the world, and particularly in mountain rangelands. To understand this process it is necessary to develop methods to assess soil erosion rate in a quick, economic and accurate manner. Based on the analysis of exposed Polylepis australis roots, we tested a dendrogeomorphological method for determining soil loss rate in rills and gullies. Few studies considered non-coniferous tree rings in soil erosion analysis and we used, for the first time, an experimental procedure of root exposure and provided a comparison with roots exposed by gully erosion. Our main results showed that as a consequence of soil erosion, exposed roots changed from root-like to a more stem-like wood anatomical structure. The percentage of vessel area per tree-ring area decreases by an average of 22% to 43% during the first and second year after exposure, respectively. Moreover, and during the same time interval, the mean vessel area decreased 32% and 65%, and the number of vessels increased 7% and 48%, respectively. Scars formed at the upper side of the exposed roots are coincident with changes in wood anatomy, and both evidences may be applied to reconstruct an erosion process. This study confirms that the wood anatomy analysis of partially exposed roots can be used to determine the year in which roots are exposed and provides a useful tool to monitor soil erosion rates with a high accuracy.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): P. Šamonil, J. Timková, I. Vašíčková The use of individual-based models in the study of the spatial patterns of disturbances has opened new horizons in forest ecosystem research. However, no studies so far have addressed (i) the uncertainty in geostatistical modelling of the spatial relationships in dendrochronological data, (ii) the number of increment cores necessary to study disturbance spatial patterns, and (iii) the choice of an appropriate geostatistical model in relation to disturbance regime. In addressing these issues, we hope to contribute to advances in research methodology as well as to improve interpretations and generalizations from case studies. We used data from the beech-dominated Žofínský Prales forest reserve (Czech Republic), where we cored 3020 trees on 74 ha. Block bootstrap and geostatistics were applied to the data, which covered five decades with highly different disturbance histories. This allowed us to assess the general behavior of various mathematical models. Uncertainty in the spatial patterns and stability of the models was measured as the length of the 95% confidence interval (CI) of model parameters. According to Akaike Information Criterion (AIC), the spherical model fitted best at the range of ca. 20 m, while the exponential model was best at the range of ca. 60 m. However, the best fitting models were not always the most stable. The stability of models grew significantly with sample size. At 〈500 cores the spherical model was the most stable, while the Gaussian model was very unstable at 〈300 cores. The pure nugget model produced the most precise nugget estimate. The choice of model should thus be based on the expected spatial relations of the forest ecosystem under study. Sill was the most stable parameter, with an error of ±6–20% for ≥1110 core series. By contrast, practical range was the most sensitive, with an error of at least ±59%. The estimation of the spatial pattern of severe disturbances was more precise than that of fine-scale disturbances. The results suggest that with a sample size of 1000–1400 cores and a properly chosen model, one reaches a certain precision in estimation that does not increase significantly with growing sample size. It appears that in temperate old-growth forests controlled by fine-scale disturbances, it is necessary to have at least 500 cores to estimate sill, nugget and relative nugget, while to estimate practical range at least 1000 cores are needed. When choosing the best model, the stability of the model should be considered together with the value of AIC. Our results indicate the general limits of disturbance spatial pattern studies using dendrochronological and geostatistical methods, which can be only partially overcome by sample size or sampling design.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): L. Dinis, M.M. Savard, P. Gammon, C. Bégin, J. Vaive This study investigates Pb isotope ratios at low concentrations (parts per billion; ppb) in tree rings and soils in the Northern Athabasca Oil Sands Region (NAOSR), western Canada, to evaluate if: (1) climatic conditions influence on tree-ring Pb assimilation; and (2) such low Pb content allows inferring the regional Pb depositional history. Our results reflect the influence of winter snow cover and the importance of minimum temperature and precipitation in spring and summer on the bioavailability of Pb and its passive assimilation by trees in sub-arctic semi-humid climatic conditions. Winter conditions can influence the state of root systems that subsequently impacts the following growth period, while spring and summer conditions likely control microbial processes and water source, and may thus impact Pb assimilation by trees. Thus, the results of tree-ring Pb concentrations show interesting correlation with cumulated snow from November of the previous year to February ( ρ = 0.53; P 〈 0.01; n = 36). Likewise, the 206 Pb/ 207 Pb ratios inversely correlate with minimum temperature from April to September ( ρ = −0.67; P 〈 0.01; n = 40) and precipitation from May to August ( ρ = −0.42; P 〈 0.01; n = 36). The isotopic results also suggest that the effects of climatic variations are superimposed by regional industrial Pb deposition: Western North American Aerosols (WNAA) and fugitive dust from the oil sands mining operations appear to be the most likely sources. Importantly, this study suggests that even at low Pb concentrations, tree-ring Pb isotopes are modulated by climatic conditions and potential input of regional and long-range transport of airborne Pb. These interpretations open the possibility of using Pb isotopes as an environmental tool for inferring the pollution history in remote regions, and improving our understanding of its natural cycle through the forest environment.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Douglas J. Stevenson, Thomas B. Lynch, Pradip Saud, Robert Heineman, Randal Holeman, Dennis Wilson, Keith Anderson, Chris Cerny, James M. Guldin Each year severe winter storms (≈ice storms) damage trees throughout the southern USA. Arkansas and Oklahoma have a history of severe winter storms. To extend that history back beyond the reach of written records, a distinctive tree ring pattern or signature is needed. Storm-caused breakage, branch loss and bending stress provide that signature. We found a severe storm signature in shortleaf pine ( Pinus echinata ). We used three published site chronologies, a set of five new site chronologies from a growth-and-yield study conducted by Oklahoma State University and the unpublished Shortleaf Canyon chronology from a master’s thesis at the University of Arkansas. Our method is based on two ring width values for the first and second growing seasons after the storm standardized to the ring widths of the seven growing seasons after the storm. Concordance between storm years predicted by tree ring patterns and actual storm years was tested using Cohen’s Kappa. Concern about confounding of ice storm signals by droughts led us to test concordance between severe storms and drought in July, August and September; results were inconclusive but stand as a warning that these two phenomena cannot be distinguished with certainty in the tree ring record. Damaging severe storms occurred in about 2.8% of all years. Two out of three storms identified as “severe” produced glaze icing.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Julieta Gabriela Arco Molina, Martín Ariel Hadad, Daniel Patón Domínguez, Fidel Alejandro Roig Frost events may damage the cambium and consequently the newly produced tracheids whose cell walls have not yet completed their lignifications, leading to the formation of frost rings. This study deals with the presence of frost rings in Araucaria araucana trees according to cambial age and bark thickness, under the assumption that these factors may be involved in physical or physiological mechanisms that increase resistance to freezing temperatures that impact the cambial tissue. The study was conducted in northern Patagonia at two sites of contrasting geomorphology, and therefore potentially associated with a differential degree of exposure to extreme cold. Wood plus bark cores were extracted from main stems at two heights from the ground and from each of the four cardinal point directions for 30 individuals per site. A Linear Mixed Model and a Generalized Linear Mixed Model were applied in order to relate the bark thickness and the frequency of frost rings in accordance with the different sampling points on the stem. It was observed that as bark becomes thicker with cambial age, the frequency of frost rings decreases, indicating a possible thermal-induced mechanism of bark protection. Consequently, there is an increase in the presence of frost rings at the younger stages of tree life. Although the mechanisms of cold hardiness in trees can be complex, including aspects of the tree physiology, our data indicated that as tree age increases, the thickness of the bark is higher, resulting in a potential effect of isolation and passive protection against the harmful effects of frosts. This mechanism may be relevant in the ecology, conservation and management of forests faced with extreme variability in future climate and changing scenarios.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Dominik Florian Stangler, Martin Mann, Hans-Peter Kahle, Elena Rosskopf, Siegfried Fink, Heinrich Spiecker Studying intra-annual wood formation dynamics provides valuable information on how tree growth and forests are affected by environmental changes and climatic extreme events. This study has the aim to evaluate and to quantify synergetic potentials emerging from a combination of current state of the art techniques used to monitor intra-annual wood formation processes. Norway spruce trees were studied in detail during the growing season 2009 with weekly sampling of microcores, high resolution point-dendrometers and wood anatomical analysis. The combination of the applied techniques allowed us to convert the spatial scales of radial tracheid diameter profiles to seasonal time scales and to synchronize fluctuations in intra-annual cell diameter profiles. This spatiotemporal information was used to validate the recently introduced software MICA ( Multiple interval-based curve alignment ) . In comparison to the conventional approach of averaging profiles of tree ring variables, the MICA aligned profiles exhibit a significantly higher synchronicity of the averaged data points. We also demonstrate two new features in the MICA application that enable to extrapolate spatiotemporal information between intra-annual profiles for the construction of robust mean (consensus) profiles that are representative for the population dynamics. By using a set of complementary techniques in an integrated approach, this study highlights a new methodological framework that can contribute to a better understanding of the environmental control of wood formation during the growing season.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Filipe Campelo, Cristina Nabais, Ana Carvalho, Joana Vieira Here we present the package tracheideR to standardize profiles of tracheid features, using the R computing environment. This package contains a collection of functions to transform the raw data obtained from image analysis into a tracheidogram to better visualize the radial intra-ring variation of histometric parameters. This procedure is crucial when estimating past weather conditions with a sub-annual resolution, since tracheidograms reflect the influence of fluctuations in weather conditions throughout the growing season (such as temperature and soil water content). The main function of this package is tracheider , which takes as input raw tracheidograms and standardizes them using three different methods. The first method standardizes the number of tracheids from different radial files to the mean number of cells, allowing that different annual rings have different number of cells. The second method normalizes the number of cells of different annual rings to the same number. Finally we present a new method to standardize histometric parameters considering the relative position of the cells within the tree ring. This package was tested using two rings of Pinus pinaster to demonstrate variations between the three methods. According to our results species with high intra- and inter-annual variability, as shown by conifers species growing under Mediterranean climate, should be standardized using the “relative position” method. Finally, we suggest that this new method should be applied to other species to check its potential to detect intra-ring fluctuations in tracheid features and to improve our capacity to detect intra-annual climatic signals.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Paolo Cherubini

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Jean-Philippe Martin, Daniel Germain Dendrogeomorphology has been recognized as a useful tool to reconstruct past snow avalanche chronologies, especially in remote areas where archives are non-existent. In recent years, there have been a multiplicity of snow avalanche studies based on tree-ring analysis. Yet, the dendrogeomorphic procedure applied to snow avalanches still lacks consensus within the scientific community. This paper illustrates four issues regarding this method encountered on a dataset encompassing 293 trees sampled from 4 sites in the White Mountains (New Hampshire, United States). (1) Separating a sample in an upslope and downslope subgroup allowed to reconstruct a more thorough avalanche chronology. (2) On the other hand, a strong response at a site sheltered from any avalanche track was attributed to extreme snow loadings with a return period well above 100 years. (3) In addition to climatic disturbances, ecological disturbances such as windthrows can cause an anatomical response in the trees similar to snow avalanches. An avalanche track might act as a wind tunnel, making the underlying runout zone a suitable site to windfalls. Sampling in transects can assist in determining the limit between avalanche-related and wind-related disturbances. (4) Early-spring torrential floods and avalanche activities at a multi-process site exhibit distinct spatial patterns in the dendrogeomorphological response that allow discrimination between the two processes in the reconstruction of past chronologies. While the dendrogeomorphologist should be cautious of these issues, their acknowledgement is an opportunity to understand the interactions between the different ecological, climatic and geomorphological processes operating on the forested slopes in the alpine–subalpine environment.

Description: Publication date: Available online 23 February 2016 Source: Dendrochronologia Author(s): Irina P. Panyushkina, Alexei A. Karpukhin, Asya V. Engovatova Investigations of interactions between climate change and humans suffer from the lack of climate proxies directly linked to historical or archaeological datasets that describe past environmental conditions at a particular location and time. We present a new set of pine tree-ring records ( Pinus sylvestris L.) developed from burial timbers excavated at the historical center of Yaroslavl city, Russia. A 171-year δ 13 C tree-ring chronology from AD 1430 to AD 1600 evidences mostly wet summers during the 15th century but exceptionally dry conditions of the 16th century at the Upper Volga catchment. According to the tree-ring record there were four major droughts (〈−1.5 σ ) lasting from 9 to 26 years: 1501–1517, 1524–1533, 1542–1555 and 1570–1596, and major pluvials (>+1.5 σ ) lasting from 70 to 5 years: 1430–1500, 1518–1523, 1534–1541, and 1556–1564. We discuss a plausible contribution of these droughts to crop failures and city fires documented with historical chronicles for the Upper Volga catchment. The devastating drought regime of the 16th century corresponds to the loss of independence of the Yaroslavl principality to the Grand Duchy of Moscow and the formation of the centralized Russian State during the reign of Ivan the Terrible (1533–1584) underpinning the emergence of the Russian Empire. This study substantiates the value of archaeological timbers from the oldest Russian cities and inclusion of stable carbon isotope analysis for understanding hydroclimatic regimes across the mid latitudes of East European Plain, and their relationship to the history of Russia. Graphical abstract

Description: Publication date: Available online 4 February 2016 Source: Dendrochronologia Author(s): James H. Speer, Achim Bräuning, Qi-Bin Zhang, Kambiz Pourtahmasi, Narayan P. Gaire, Binod Dawadi, Prabina Rana, Yub Raj Dhakal, Ram Hari Acharya, Dhruba Lochan Adhikari, Shankar Adhikari, Prakash Chandra Aryal, Damodar Bagale, Binod Baniya, Sanjaya Bhandari, Navin Dahal, Suchana Dahal, Narmandakh Ganbaatar, Anjana Giri, D.B Gurung, Yeshey Khandu, Binu Maharjan, Rajan Maharjan, Rayees Ahmad Malik, Cheryl D. Nath, Bikash Nepal, Justine Ngoma, Ramesh Pant, Mitra Lal Pathak, Hari Paudel, Bimal Sharma, Md Sarwar Hossain, Bayarbaatar Soronzonbold, Thida Swe, Ichchha Thapa, Achyut Tiwari The fieldweek associated with the 4th Asian Dendrochronological Association Conference was an excellent opportunity for education, networking, and research. The participants and group leaders worked together for five days in an area that was new to some of the group leaders and new to some of the participants which enabled us to learn about forest ecology around Kathmandu and Nagarkot, Nepal. The fieldweek was an excellent networking opportunity and the group leaders and participants bonded which strengthened international research in dendrochronology and continues to foster new research collaborations. All of the group leaders and participants had the opportunity to learn about tree-ring formation in Pinus roxburghii at 1500 masl elevation, to explore its wood anatomy, and to examine specific research questions in our field area. In the end we developed a better understanding of the stand-age structure of a stand of trees in Nagarkot, explored the erosion history from exposed roots, and investigated tree health issues on closely related sites. We found that P. roxburghii poses some dating issues with false and micro rings at this elevation, but we were still able to develop a tree-ring chronology from this species and make preliminary assessments of stand dynamics and health.

Description: Publication date: Available online 15 March 2016 Source: Dendrochronologia Author(s): Ekaterina Dolgova Although long-lived trees grow in the Northern Caucasus, no single tree-ring chronology has been reported thus far from this area in the International Tree-Ring Data Base (ITRDB), neither has one been published in international journals. Extensive tree-ring studies were conducted over the last decade, and a tree-ring network was developed for the investigated area. The data on the minimum blue intensity based on 33 series of pine ( Pinus sylvestris L.) and fir ( Abies nordmanniana (Steven) Spach) is presented in this study. The minimum blue intensity (BI) chronology covers the period 1596–2011 with EPS value ≥0.85. The BI chronology strongly correlates with the mean June-September temperature (R = 0.74; p 〈 0.05) from the weather station “Kluhorskij Pereval” (1951–2011). Mean June-September temperature anomalies were reconstructed using the rescaling method. Based on the reconstruction provided in this study the twentieth century is characterized by highly increased June-September temperature. According to this study, the minimum blue intensity approach demonstrates a great potential for paleoclimatic research in the Caucasus. Vast spatial coverage of the new BI-based reconstruction based on data from only two locations in the Northern Caucasus provides prospects for reconstruction of temperature variations for a great region in the Middle East and Northern Africa.

Description: Publication date: Available online 14 December 2015 Source: Dendrochronologia Author(s): Anna V. Taynik, Valentin V. Barinov, Orlan Ch. Oidupaa, Vladimir S. Myglan, Frederick Reinig, Ulf Büntgen Tree-ring research in the Altai-Sayan Mountains so far only considered a limited number of well-replicated site chronologies. The dendroecological and palaeoclimatological potential and limitations of large parts of south-central Russia therefore remain rather unexplored. Here, we present a newly updated network of 13 larch ( Larix sibirica Ldb.) tree-ring width (TRW) chronologies from mid to higher elevations along a nearly 1000 km west-to-east transect across the greater Altai-Sayan region. All data were sampled between 2009 and 2014. The corresponding site chronologies cover periods from 440 to 860 years. The highest TRW agreement is found between chronologies ≥2200 m asl, whereas the material from lower elevations reveals overall less synchronized interannual to longer-term growth variability. While fluctuations in average June–July temperature predominantly contribute to the growth at higher elevations, arid air masses from Mongolia mainly affect TRW formation at lower elevations. Our results are indicative for the dendroclimatological potential of the Altai-Sayan Mountains, where both, variation in summer temperature and hydroclimate can be robustly reconstructed back in time. These findings are valid for a huge region in central Asia where reliable meteorological observations are spatially scarce and temporally restricted to the second half of the 20th century. The development of new high-resolution climate reconstruction over several centuries to millennia will further appear beneficial for timely endeavors at the interface of archaeology, climatology and history.

Description: Publication date: November 2015 Source: Dendrochronologia, Volume 36 Author(s): Maryann R. Pirie, Anthony M. Fowler, Christopher M. Triggs Knowing the number of rings from the pith to the last cross-dated ring on incremental cores is important for regional curve standardisation, for constructing the best chronology by excluding rings formed when the tree was young, and for forest stand dynamics and regeneration studies. As the pith is rarely present on the samples an estimate of the distance to the pith is required. The aim of this paper is to assess the accuracy of three commonly used pith offset estimation methods for estimating pith offsets from kauri incremental cores. Literature identifies three main approaches for estimating pith offsets: Duncan’s geometric method, the concentric circles method (CCM), and the radius–length method. The accuracy of geometric and CMM were assessed using virtual cores constructed from an Agathis australis (Kauri) cross-section. Then the estimates for all three methods were applied to a subset of the kauri incremental cores database. The most accurate method for estimating the pith offset for kauri trees was found to be geometric method, followed by CCM. However, these approaches could only be used to estimate the pith offset for a few cores as they require the core to pass close enough to the pith that there is visible curvature on the cores. For most cores the radius–length method is the only method available for estimating the pith offset. This method relies on the assumption that the pith is located at the geometric centre of the tree which may not be a valid assumption for some species.

Description: Publication date: Available online 11 January 2016 Source: Dendrochronologia Author(s): Lena Hellmann, Leonid Agafonov, Olga Churakova (Sidorova), Elisabeth Düthorn, Ólafur Eggertsson, Jan Esper, Alexander V. Kirdyanov, Anastasia A. Knorre, Pavel Moiseev, Vladimir S. Myglan, Anatoly N. Nikolaev, Frederick Reinig, Fritz Schweingruber, Olga Solomina, Willy Tegel, Ulf Büntgen Arctic driftwood represents a unique proxy archive at the interface of marine and terrestrial environments. Combined wood anatomical and dendrochronological analyses have been used to detect the origin of driftwood and may allow past timber floating activities, as well as past sea ice and ocean current dynamics to be reconstructed. However, the success of driftwood provenancing studies depends on the length, number, and quality of circumpolar boreal reference chronologies. Here, we introduce a Eurasian-wide high-latitude network of 286 ring width chronologies from the International Tree Ring Data Bank (ITRDB) and 160 additional sites comprising the three main boreal conifers Pinus , Larix , and Picea . We assess the correlation structure within the network to identify growth patterns in the catchment areas of large Eurasian rivers, the main driftwood deliverers. The occurrence of common growth patterns between and differing patterns within catchments indicates the importance of biogeographic zones for ring width formation and emphasizes the degree of spatial precision when provenancing. Reference chronologies covering millennial timescales are so far restricted to a few larch sites in Central and Eastern Siberia (eastern Taimyr, Yamal Peninsula and north-eastern Yakutia), as well as several pine sites in Scandinavia, where large rivers are missing though. The general good spatial coverage of tree-ring sites across northern Eurasia indicates the need for updating and extending existing chronologies rather than developing new sites.

Description: Publication date: Available online 4 February 2016 Source: Dendrochronologia Author(s): Achyut Tiwari, Ze-Xin Fan, Alistair S. Jump, Shu-Feng Li, Zhe-Kun Zhou Population structure and tree recruitment dynamics in the natural treeline ecotone of high mountains are strong indicators of vegetation responses to climate. Here, we examined recruitment dynamics of Abies spectabilis across the treeline ecotone (3439–3638 m asl) of Chimang Lekh of Annapurna Conservation Area in the Trans-Himalayan zone of central Nepal. Dendrochronological techniques were used to establish stand age structure by ring counts of adults, and by terminal bud scar count for seedlings and saplings. The results showed abundant seedling recruitment, higher regenerative inertia and colonization with a consistent range shift of the A. spectabilis treeline. The upward expansion of this sub-alpine treeline was found to be driven by a strong dependence of seedling recruitment and radial growth on snowmelt and precipitation as temperatures rise. The radial growth of A. spectabilis at the alpine timberline ecotone (ATE) and closed timberline forest (CTF) showed sensitivity to spring season (March–May) climate. Tree ring indices of CTF showed a strong positive correlation with spring and annual precipitation, and a significant negative correlation with spring and annual temperature, however, moisture sensitivity was less strong at ATE than CTF.

Description: Publication date: Available online 31 December 2015 Source: Dendrochronologia Author(s): Olga V. Churakova (Sidorova), Aleksandr V. Shashkin, Rolf T.W. Siegwolf, Renato Spahni, Thomas Launois, Matthias Saurer, Marina V. Bryukhanova, Anna V. Benkova, Anna V. Kuptsova, Philippe Peylin, Eugene A. Vaganov, Valerie Masson-Delmotte, John Roden Tree-ring width and stable isotopic composition are widely used for the reconstruction of environmental conditions. Eco-physiological models simulating δ 13 C and δ 18 O provide tools to constrain the interpretation of measured tree-ring variations and their relationships to environmental variables. Here, we apply biochemical models of photosynthesis and a model of stomatal conductance to simulate the intra-annual dynamics of δ 13 C values in photo assimilates and tree-rings. We use these models to investigate the physiological responses of larch trees growing on permafrost to variability in precipitation and permafrost depth associated with regional temperature and precipitation changes. Tree-ring width, δ 13 C and δ 18 O in wood and cellulose were measured in larch ( Larix cajanderi Mayr.) samples from northeastern Yakutia (69°N, 148°E) for the period from 1945 to 2004 and used for comparisons with modeled δ 13 C and δ 18 O data. Mechanistic models that quantify physical and biochemical fractionation processes leading to oxygen isotope variation in organic matter are used to identify source water for trees growing on permafrost in Siberia. These models allowed us to investigate the influence of a variety of climatic factors on Siberian forest ecosystem water relations that impact isotope fractionation. Based on δ 13 C and δ 18 O in tree wood and cellulose measurements as well as outputs from different eco-physiological models, we assume that larch trees from northeastern Yakutia can have limited access to the additional thawed permafrost water during dry summer periods.

Description: Publication date: Available online 20 October 2015 Source: Dendrochronologia Author(s): Vladimir V. Shishov, Ivan I. Tychkov, Margarita I. Popkova, Viсtor A. Ilyin, Marina V. Bryukhanova, Alexander V. Kirdyanov It is generally assumed in dendroecological studies that annual tree-ring growth is adequately determined by a linear function of local or regional precipitation and temperature with a set of coefficients that are temporally invariant. However, various researchers have maintained that tree-ring records are the result of multivariate, often nonlinear biological and physical processes. To describe critical processes linking climate variables with tree-ring formation, the process-based tree-ring Vaganov–Shashkin model (VS-model) was successfully used. However, the VS-model is a complex tool requiring a considerable number of model parameters that should be re-estimated for each forest stand. Here we present a new visual approach of process-based tree-ring model parameterization (the so-called VS-oscilloscope) which allows the simulation of tree-ring growth and can be easily used by researchers and students. The VS-oscilloscope was tested on tree-ring data for two species ( Larix gmelinii and Picea obovata ) growing in the permafrost zone of Central Siberia. The parameterization of the VS-model provided highly significant positive correlations ( p 〈 0.0001) between simulated growth curves and original tree-ring chronologies for the period 1950–2009. The model outputs have shown differences in seasonal tree-ring growth between species that were well supported by the field observations. To better understand seasonal tree-ring growth and to verify the VS-model findings, a multi-year natural field study is needed, including seasonal observation of the thermo-hydrological regime of the soil, duration and rate of tracheid development, as well as measurements of their anatomical features.

Description: Publication date: Available online 30 October 2015 Source: Dendrochronologia Author(s): Vladimir Matskovsky, Andrey Dolgikh, Konstantin Voronin Dendrochronology is usually the only method of precise dating of unsigned art objects made on or of wood. It has a long history of application in Europe, however in Russia such an approach is still at an infant stage, despite its cultural importance. Here we present the results of dendrochronological and radiocarbon accelerated mass spectrometry (AMS) dating of three medieval icons from the 15th–17th century that originate from the North of European Russia and are painted on wooden panels made from Scots pines. For each icon the wooden panels were dendrochronologically studied and five to six AMS dates were made. Two icons were successfully dendro-dated whereas one failed to be reliably cross-dated with the existing master tree-ring chronologies, but was dated by radiocarbon wiggle-matching. Wiggle-matching of radiocarbon dates is the most promising method for dating Russian icons in the absence of a dense dendrochronological network. However, for this case uncertainties connected with the radiocarbon method have to be taken into account and further studies of these uncertainties must be undertaken by comparing dendro-dated and radiocarbon-dated wooden works of art. Our results, moreover, showed that in two cases art-historical dates were by five to ten decades older than the earliest possible time of the creation of the icons, based on dendrochronology.

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Progress in Oceanography, Volume 170〈/p〉 〈p〉Author(s): Alba María Martínez–Pérez, Teresa S. Catalá, Mar Nieto–Cid, Jaime Otero, Marta Álvarez, Mikhail Emelianov, Isabel Reche, Xosé Antón Álvarez–Salgado, Javier Arístegui〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fluorescent dissolved organic matter (FDOM) in the Mediterranean Sea was analysed by excitation–emission matrix (EEM) spectroscopy and parallel factor (PARAFAC) analysis during the cruise HOTMIX 2014. A 4–component model, including 3 humic–like and 1 protein–like compounds, was obtained. To decipher the environmental factors that dictate the distributions of these components, we run generalized additive models (GAMs) in the epipelagic layer and an optimum multiparametric (OMP) water masses analysis in the meso– and bathypelagic layers. In the epipelagic layer, apparent oxygen utilization (AOU) and temperature presented the most significant effects on the variability of the marine humic-like peak M fluorescence, suggesting that its distribution was controlled by the net community respiration of organic matter and photobleaching. On the contrary, the variability of the soil humic-like peak E and the protein–like peak T fluorescence was explained mainly by the prokaryotic heterotrophic abundance, which decreased eastwards. In the meso– and bathypelagic layers, water mass mixing and basin–scale mineralization processes explained 〉72% and 63% of the humic–like and protein–like fluorescence variability, respectively. When analysing the two basins separately, the OMP model offered a better explanation of the distribution of fluorescence in the eastern Mediterranean Sea, as expected from the reduced biological activity in this ultra–oligotrophic basin. Furthermore, while western Mediterranean deep waters display the usual trend in the global ocean (increase of humic–like fluorescence and decrease of protein–like fluorescence with higher AOU values), the eastern Mediterranean deep waters presented an opposite trend. Different initial fluorescence intensities of the water masses that mix in the eastern basin, with Adriatic and Aegean origins, seem to be behind this contrasting pattern. The analysis of the transect–scale mineralization processes corroborate this hypothesis, suggesting a production of humic–like and a consumption of protein–like fluorescence in parallel with water mass ageing. Remarkably, the transect–scale variability of the chromophoric dissolved organic matter (CDOM) absorbing at the excitation wavelength of the humic–like peak M indicates an unexpected loss with increasing AOU, which suggests that the consumption of the non–fluorescent fraction of CDOM absorbing at that wavelength exceeded the production of the fluorescent fraction observed here.〈/p〉〈/div〉 〈/div〉

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: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid State Ionics, Volume 327〈/p〉 〈p〉Author(s): W.G. Wang, X.Y. Li, T. Liu, G.L. Hao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The electrical performances and relaxation behaviors of the Na〈sub〉0.525〈/sub〉Bi〈sub〉0.475〈/sub〉TiO〈sub〉2.975〈/sub〉 and Bi-deficient Na〈sub〉0.51〈/sub〉Bi〈sub〉0.48〈/sub〉TiO〈sub〉2.975〈/sub〉 sample were investigated. The grain conductivity of the Na〈sub〉0.525〈/sub〉Bi〈sub〉0.475〈/sub〉TiO〈sub〉2.975〈/sub〉 sample is able to reach 1.51 × 10〈sup〉−3〈/sup〉 S/cm at 673 K. In the temperature range of measurement, the grain conductivity of the Bi-deficient Na〈sub〉0.51〈/sub〉Bi〈sub〉0.48〈/sub〉TiO〈sub〉2.975〈/sub〉 sample is lower than that of the Na〈sub〉0.525〈/sub〉Bi〈sub〉0.475〈/sub〉TiO〈sub〉2.975〈/sub〉 sample. By the internal friction and dielectric relaxation spectrum, the activation energy and relaxation time at infinite temperature were determined as (0.82 eV, 2.47 × 10〈sup〉−14〈/sup〉 s), (0.67 eV, 5.82 × 10〈sup〉−12〈/sup〉 s) and (0.85 eV, 5.8 × 10〈sup〉−13〈/sup〉 s), (0.52 eV, 2.55 × 10〈sup〉−10〈/sup〉 s) for the Na〈sub〉0.525〈/sub〉Bi〈sub〉0.475〈/sub〉TiO〈sub〉2.975〈/sub〉 and Na〈sub〉0.51〈/sub〉Bi〈sub〉0.48〈/sub〉TiO〈sub〉2.975〈/sub〉 samples at the different temperature regions. In the Na〈sub〉0.525〈/sub〉Bi〈sub〉0.475〈/sub〉TiO〈sub〉2.975〈/sub〉 compound, there is larger specific free volume, higher mobile oxygen vacancy content and better oxygen vacancy mobility, which cause the higher grain conductivity in the Na〈sub〉0.525〈/sub〉Bi〈sub〉0.475〈/sub〉TiO〈sub〉2.975〈/sub〉 compound. To some extent, by the Bi-deficient method, oxygen vacancies can be introduced into the Na〈sub〉0.51〈/sub〉Bi〈sub〉0.48〈/sub〉TiO〈sub〉2.975〈/sub〉 compound and the grain conductivity may be improved, but the other side of Bi-deficiency harms the oxygen vacancy diffusion capacities in the Na〈sub〉0.5〈/sub〉Bi〈sub〉0.5〈/sub〉TiO〈sub〉3〈/sub〉 compound.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid State Ionics, Volume 327〈/p〉 〈p〉Author(s): Yonrapach Areerob, Ju Yong Cho, Won Kweon Jang, Kwang Youn Cho, Won-Chun Oh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A cost effective and efficient alternative counter electrode (CE) to replace commercially existing platinum (Pt)-based CEs for dye-sensitized solar cells (DSSCs) is necessary to make DSSCs competitive. Herein, we report the model-controllable synthesis of Graphene-La〈sub〉6〈/sub〉W〈sub〉2〈/sub〉O〈sub〉15〈/sub〉 doped NiSe-CoSe quantum dot (GLW-NiCoSe) nanosheets with various NiCoSe content via simple hydrothermal method and used as CE for DSSC application. Electrochemical impedance spectroscopy (EIS) results confirmed that the as-synthesized GLW-NiCoSe nanosheets quantum dot exhibited good electrocatalytic properties and a low charge transfer resistance at the electrolyte-electrode interface. In addition, Thermal images and Photocurrent also demonstrate stability effect of material with more exposed edge sites and appropriate NiCoSe ratio. GLW-NiCoSe nanosheets performed rough surfaces, well-defined interior voids, large specific surface areas and outstanding catalytic actives. Finally, the mechanism of this material has been reported. All of these results showed a high energy conversion efficiency of up to 8%, which was comparable to the Pt CE (7%). The simple fabricated and good electrocatalytic properties of GLW-NiCoSe nanosheets make them as an alternative CE for DSSCs.〈/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-S0167273818304910-ga1.jpg" width="314" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid State Ionics, Volume 327〈/p〉 〈p〉Author(s): Ho-Young Jung, Geon-O Moon, T. Sadhasivam, Chang-Soo Jin, Won-Shik Park, Hee-Tak Kim, Sung-Hee Roh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To confirm the viability of a porous polyethylene (PE) separator for using in vanadium redox flow batteries (VRFBs), we conduct a comparative electroanalytical and chemical stability studies of the PE separator and Nafion 212 membrane. We characterize the physicochemical properties of the separator, such as water uptake, dimensional change, and ion conductivity, and analyze its structural and compositional features using thermogravimetric analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. We also test the chemical stability of the separator against highly oxidative V〈sup〉5+〈/sup〉 ions and the cell performance of VRFB using PE separator to assess practical applicability. In chemical stability, the change of VO〈sub〉2〈/sub〉〈sup〉+〈/sup〉 ion to VO〈sup〉2+〈/sup〉 ion is considerably lowered by the PE separator (0.01 mmol/L) than the Nafion 212 (0.27 mmol/L), which indicates that the PE separator possesses higher chemical stability. The energy efficiency of the VRFB with the PE separator is lower than that obtained with Nafion 212. However, the chemical stability of PE separator is 27 times higher than that of Nafion 212, indicating that its use will promote the long-term operation of the VRFB system. Hence, the PE separator can be considered a cost-effective option for VRFB operation, with appropriate modifications to its thickness, surface properties and pore structure.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 4, Issue 11〈/p〉 〈p〉Author(s): Karen Gu, Lawrence Mok, Mark M.W. Chong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The expression of any gene must be precisely controlled for appropriate function. This expression can be controlled at various levels. This includes epigenetic regulation through DNA methylation or histone modifications. At the posttranscriptional level, regulation can be via alternative splicing or controlling messenger RNA (mRNA) stability. RNA cleavage is one way to control mRNA stability. For example, microRNA (miRNA)-induced mRNA cleavage has long been recognised in plants. RNA cleavage also appears to be widespread in other kingdoms of life, and it is now clear that mRNA cleavage plays critical functions in animals. Although miRNA-induced mRNA cleavage can occur in animals, it is not a widespread mechanism. Instead, mRNA cleavage can be induced by a range of other mechanisms, including by endogenous short inhibitory RNAs (endo-siRNAs), as well as the Ribonuclease III (RNase III) enzymes Drosha and Dicer. In addition, RNA cleavage induced by endo-siRNAs and PIWI-interacting RNAs (piRNAs) is important for genome defence against transposons. Moreover, several RNase has been identified as important antiviral mediators. In this review, we will discuss these various RNA endonucleolytic cleavage mechanisms utilised by animals to regulate the expression of genes and as a defence against retrotransposons and viral infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Surface Science, Volume 681〈/p〉 〈p〉Author(s): Qingjun Chen, Ingeborg-Helene Svenum, Ljubisa Gavrilovic, De Chen, Edd A. Blekkan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Trace amounts of potassium (K) have a significant influence on the activity and selectivity of cobalt-based catalysts in Fischer–Tropsch synthesis (FTS), in which hydrogen adsorption and dissociation is one of the initial and most important steps. In this work, hydrogen adsorption and dissociation behavior on typical facets ((0001), (10–11), (10–12), (10–15) and (11–20)) of hcp Co with and without adsorbed K were systematically studied. H〈sub〉2〈/sub〉 molecular adsorption results showed that H〈sub〉2〈/sub〉 mainly adsorbed in the perpendicular mode and close to the state of free H〈sub〉2〈/sub〉. Different facets and pre-adsorbed K did not show obvious effects on the H〈sub〉2〈/sub〉 adsorption energy. Atomic hydrogen adsorption was site and facet dependent, but the maximum hydrogen adsorption energy on the different facets of hcp Co were similar (-2.64 to -2.67 eV) with the exception on the (11–20) facet where the adsorption energy was significantly lower (-2.44 eV). K had a slight destabilizing effect on the H atom adsorption on the former Co surfaces due to a very weak repulsive interaction between K and H atoms. The initial H〈sub〉2〈/sub〉 dissociation had negligible energy barriers (0–0.07 eV) on the clean surface of hcp Co, suggesting the direct dissociative adsorption of H〈sub〉2〈/sub〉. The energy barriers for H〈sub〉2〈/sub〉 dissociation are mainly caused by the approach of molecular H〈sub〉2〈/sub〉 towards the Co surface and the rotation of the H〈sub〉2〈/sub〉 molecule from the perpendicular mode to the parallel mode. The H〈sub〉2〈/sub〉 dissociation energy barriers increase by 0.02–0.17 eV after the pre-adsorption of K, indicating a slight inhibition of H〈sub〉2〈/sub〉 dissociation by K. However, the energy barriers for H〈sub〉2〈/sub〉 dissociation in the presence of K were also small (0.05–0.21 eV). This indicates that H〈sub〉2〈/sub〉 dissociates readily at typical Co-based FTS reaction temperatures (210–240 °C), both in the absence and presence of K. Different K species (K and KOH) exhibit similar effects on H〈sub〉2〈/sub〉 dissociation on hcp Co. The B〈sub〉5〈/sub〉 sites on the stepped facets, the preferred sites for K adsorption are not the most favorable site for H〈sub〉2〈/sub〉 dissociation, and K slightly hinders H〈sub〉2〈/sub〉 dissociation at the B〈sub〉5〈/sub〉 site of hcp Co.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0039602818305144-fx1.jpg" width="301" alt="Image, graphical abstract" title="Image, graphical abstract"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 4, Issue 11〈/p〉 〈p〉Author(s): Seungyeon Lee, Minsung Kim, Jessica S. Mendoza, Ian M. McDonough〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A potential new clinical disorder is arising due to the addiction to cellphones called nomophobia—or feelings of discomfort or anxiety experienced by individuals when they are unable to use their mobile phones or utilize the conveniences these devices provide. However, before being able to officially classify this disorder as clinically relevant, more research needs to be conducted to determine how nomophobia relates to existing disorders. In a sample of 397 undergraduate students, the present study examined the relationship between the Nomophobia Questionnaire (NMP-Q) and the Obsessiveness Content Scale (OBS) of the Minnesota Multiphasic Personality Inventory-2 (the MMPI-2). Confirmatory factor analysis (CFA) was used to test whether the OBS Content Scale would be related to a one-factor NMP-Q solution (Fig. 1) or a four-factor NMP-Q solution (Fig. 2). Convergent and divergent validity were also investigated. The four-factor model was a better fit than the one-factor model as indicated by most fit indices. The findings showed that the OBS latent variable was correlated with all of the four NMP-Q latent variables. Mixed support was found for convergent validity, but high support was found for the divergent validity of the NMP-Q factors. This study contributes to a growing body of literature seeking to better understand the addictive nature of cellphones and takes a new perspective on addiction research and obsessiveness. These findings provide a better understanding between pre-existing assessments of personality disorders (e.g., obsessiveness) that are emerging from the overuse of mobile phones or the excessive fear of losing one's cell phone.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 4, Issue 11〈/p〉 〈p〉Author(s): Chiara Sanmartin, Francesca Venturi, Cristina Sgherri, Anita Nari, Monica Macaluso, Guido Flamini, Mike Frank Quartacci, Isabella Taglieri, Gianpaolo Andrich, Angela Zinnai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This research aimed to study the effects of packaging and storage temperature on the shelf-life of an extra virgin olive oil (EVOO) as it can occur in most points of sale. The evolution of the chemical and sensory characteristics of an EVOO, initially stored in stainless steel silos under nitrogen at 12–18 °C, was evaluated after packaging. Tinplate tin (TT) and greenish glass (GG), the most used packaging containers, and temperatures of 6 and 26 °C were taken into consideration. After 125 days from packaging all the samples maintained clearness, green and yellow reflections and the positive sensory notes of bitterness and pungency of the starting EVOO. Shelf-life of EVOO was significantly affected by different storage conditions: oil samples stored in GG at 6 °C preserved for the most part the positive attributes, whereas those stored in TT at 26 °C showed a significant presence of the rancid flavor due to oxidative processes. Moreover, samples stored in GG at 6 °C maintained the highest bitterness intensity and did not show defects at the end of the storage period. The results suggest that storage in GG at a low temperature could represent a promising storage condition to slow-down the oil degradation during market storage.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xing-Wei Xiang, Jin-Xing Xiao, Yu-Fang Zhou, Bin Zheng, Zheng-Shun Wen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The black seabream (〈em〉Sparus macrocephlus〈/em〉) is an economically pivotal aquaculture species cultured in China and Southeast Asian countries. To understand the molecular immune mechanisms underlying the response to 〈em〉Vibrio parahaemolyticus〈/em〉, a comparative gene transcription analysis were performed with utilized fresh livers of 〈em〉V. parahaemolyticus〈/em〉-immunized 〈em〉Sparus macrocephlus〈/em〉 with a control group through RNA-Seq technology. A total of 256663 contigs were obtained after excluded the low-quality sequences and assembly. The average length of contigs collected from this research is 1066.93 bp. Furthermore, blast analysis indicates 30747 contigs were annotated based on homology with matches in the NT, NR, gene, and string databases. A gene ontology analysis was employed to classify 21598 genes according to three major functional categories: molecular function, cellular component, and biological process. A total of 14470 genes were discovered in 303 KEGG pathways. RSEM and EdgeR were introduced to estimate 3841 genes significantly different expressed (False Discovery Rate〈0.001) which includes 4072 up-regulated genes and 3771 down-regulated genes. A significant enrichment analysis of these differentially expressed genes and isogenes were conducted to reveal the major immune-related pathways which refer to the toll-like receptor, complement, coagulation cascades, and chemokine signaling pathways. In addition, 92175 potential simple sequence repeats (SSRs) and 121912 candidate single nucleotide polymorphisms (SNPs) were detected and identified sequencely in the 〈em〉Sparus macrocephlus〈/em〉 liver transcriptome. This research characterized a gene expression pattern for normal and the 〈em〉V. parahaemolyticus〈/em〉 -immunized 〈em〉Sparus macrocephlus〈/em〉 for the first time and not only sheds new light on the molecular mechanisms underlying the host-〈em〉V. parahaemolyticus〈/em〉 interaction but contribute to facilitate future studies on 〈em〉Sparus macrocephlus〈/em〉 gene expression and functional genomics.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yi-Hong Chen, Jian-Guo He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The shrimp aquaculture industry is plagued by disease. Due to the lack of deep understanding of the relationship between innate immune mechanism and environmental adaptation mechanism, it is difficult to prevent and control the diseases of shrimp. The shrimp innate immune system has received much recent attention, and the functions of the humoral immune response and the cellular immune response have been preliminarily characterized. The role of environmental stress in shrimp disease has also been investigated recently, attempting to clarify the interactions among the innate immune response, the environmental stress response, and disease. Both the innate immune response and the environmental stress response have a complex relationship with shrimp diseases. Although these systems are important safeguards, allowing shrimp to adapt to adverse environments and resist infection, some pathogens, such as white spot syndrome virus, hijack these host systems. As shrimp lack an adaptive immune system, immunization therapy cannot be used to prevent and control shrimp disease. However, shrimp diseases can be controlled using ecological techniques. These techniques, which are based on the innate immune response and the environmental stress response, significantly reduce the impact of shrimp diseases. The object of this review is to summarize the recent research on shrimp environmental adaptation mechanisms, innate immune response mechanisms, and the relationship between these systems. We also suggest some directions for future research.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Heliyon, Volume 4, Issue 10〈/p〉 〈p〉Author(s): J.M. Lázaro-Guevara, B.J. Flores-Robles, K. Garrido, V. Pinillos-Aransay, A. Elena-Ibáñez, L. Merino-Meléndez, J.A. López-Martínez, R. Victoriano-Lacalle〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Background〈/h6〉 〈p〉Retinal diseases associated with the dysfunction or death of photoreceptors are a major cause of blindness around the world, improvements in genetics tools, like next generation sequencing (NGS) allows the discovery of genes and genetic changes that lead to many of those retinal diseases. Though, there very few databases that explores a wide spectrum of retinal diseases, phenotypes, genes, and proteins, thus creating the need for a more comprehensive database, that groups all these parameters.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉Multiple open access databases were compiled into a new comprehensive database. A biological network was then crated, and organized using Cytoscape. The network was scrutinized for presence of hubs, measuring the concentration of grouped nodes. Finally, a trace back analysis was performed in areas were the power law reports a high r-squared value near one, that indicates high nodes density.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉This work leads to creation of a retinal database that includes 324 diseases, 803 genes, 463 phenotypes, and 2461 proteins. Four biological networks (1) a disease and gene network connected by common phenotypes, (2) a disease and phenotype network connected by common genes, (3) a disease and gene network with shared disease or gene as the cause of an edge, and (4) a protein and disease network. The resulting networks will allow users to have easier searching for retinal diseases, phenotypes, genes, and proteins and their interrelationships.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusions〈/h6〉 〈p〉These networks have a broader range of information than previously available ones, helping clinicians in the comprehension of this complex group of diseases.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sustainable Cities and Society, Volume 44〈/p〉 〈p〉Author(s): Hye Soo Suh, Daeung Danny Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The study demonstrated a systematic approach to achieve the nearly zero energy community building through the assessment of energy performance of the combined passive and active design solutions and renewable energy systems. Among 16 community buildings, four buildings were selected and the parameters that had an impact on energy consumption were identified through the analysis of electricity and gas consumption. After the validation with the measured data of electricity and gas, the energy simulation was used to model the newly constructed community building. A combined passive and active design strategy was applied to improve the energy performance. To offset the energy use for the domestic hot water, possible renewable energy systems such as the PV system, the solar thermal system, and the geothermal heat pump system were reviewed and their efficiency was analyzed. As a result, the combination of the PV system with additional PV modules and the geothermal system was chosen for the achievement of the nearly zero energy target.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sustainable Cities and Society, Volume 44〈/p〉 〈p〉Author(s): Zhiqiang John Zhai, Jacob Michael Helman〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Climate change is a widely acknowledged major environmental problem whose impacts on building energy use however are not fully understood. Various climate models have been developed and used to project climate changes; however most of existing studies on climate change impacts only use few model outcomes, providing narrow predictions on the influences. This study analyzed a large number (i.e., 56) of models and scenarios. The obtained future climate data showed a wider range of potential changes and thus impacts on building energy. Four reference climate models were identified to cover the full range of the 56 models for three time periods and seven climate zones. The accuracy of model projections was validated using historical data. The study predicted the potential energy implications of climate changes to a campus building stock. Influences of these changes on utility and economics were analyzed. The study further explored the potential impacts of climate change to the current climate zones that directly relate to building energy consumption.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sustainable Cities and Society, Volume 44〈/p〉 〈p〉Author(s): Jorge Navarro-Rubio, Paloma Pineda, Antonio García-Martínez〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Eco-efficiency and building optimization potential of prefabricated structures to be used in new buildings are studied, focusing on the analysis of a novel dry precast beam-column connection under different durability and re-using scenarios. The analyses include structural response (via numerical models), optimization potential (material take off, building schedule and economic cost) and environmental impact (via Life Cycle Assessment, LCA). The connection is applied to a case study which is representative of common buildings: a seven-story concrete structure with frames and deck slabs. The structural response of the connection accomplishes the Eurocode safety prescriptions. Man-hours and task duration decrease around 80%, and the global schedule undergoes 60% diminution. Focusing on economic issues, when the prefabricated structural elements are reused the accumulated economic cost significantly decreases. LCA shows that durability, in terms of service life, is directly related to the environmental impact. However, other design options, such us re-using, have less repercussion in the impact categories (i.e. Global Warming Potential and Embodied Energy), and in the global cost. Results from this research could contribute to the implementation of prefabricated elements in the building stock promoting eco-efficiency.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yinnan Mu, Shimin Zhou, Ning Ding, Jingqun Ao, Xinhua Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Chemokines are a superfamily of structurally related chemotactic cytokines exerting significant roles in regulating cell migration and activation. Currently, five subgroups of fish specific CXC chemokines, named CXCL_F1-CXCL_F5, have been identified in teleost fish. However, understanding of the functions of these fish specific CXC chemokines is still limited. Here, a new member of fish specific CXC chemokines, 〈em〉Lc〈/em〉CXCL_F6, was cloned from large yellow croaker 〈em〉Larimichthys crocea〈/em〉. Its open reading frame (ORF) is 369 nucleotides long, encoding a peptide of 122 amino acids (aa). The deduced 〈em〉Lc〈/em〉CXCL_F6 protein contains a 19-aa signal peptide and a 103-aa mature polypeptide, which has four conserved cysteine residues (C〈sup〉28〈/sup〉, C〈sup〉30〈/sup〉, C〈sup〉56〈/sup〉, and C〈sup〉72〈/sup〉), as found in other known CXC chemokines. Phylogenetic analysis showed 〈em〉Lc〈/em〉CXCL_F6 formed a separate clade with sequences from other fish species, tentatively named CXCL_F6, distinct from the clades formed by fish CXCL_F1-5 and mammalian CXC chemokines. The 〈em〉Lc〈/em〉CXCL_F6 transcripts were constitutively expressed in all examined tissues and significantly up-regulated in the spleen and head kidney tissues by poly (I:C) and 〈em〉Vibrio alginolyticus〈/em〉. Its transcripts were also detected in primary head kidney leukocytes (HKLs), peripheral blood leucocytes (PBLs), and large yellow croaker head kidney (LYCK) cell line, and significantly up-regulated by poly(I:C), lipopolysaccharide (LPS), and peptidoglycan (PGN) in HKLs. Recombinant 〈em〉Lc〈/em〉CXCL_F6 protein (r〈em〉Lc〈/em〉CXCL_F6) could not only chemotactically attract monocytes/macrophages and lymphocytes from PBLs, but also enhance NO release and expression of proinflammatory cytokines (TNF-α, IL-1β, and CXCL8) in monocytes/macrophages. These results indicate that 〈em〉Lc〈/em〉CXCL_F6 plays a role in mediating the inflammatory response.〈/p〉〈/div〉 〈/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: 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: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Mechanics and Physics of Solids, Volume 122〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 99〈/p〉 〈p〉Author(s): Pablo Quero García, Javier García Sanabria, Juan Adolfo Chica Ruiz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years the European Union has firmly committed itself to energy from oceans as a means of decarbonising the European energy system. Despite a favourable political landscape, the development of offshore renewables still faces economic and technological barriers, which are coupled with the inherent difficulties of an increasingly industrialised marine environment, such as complex evolving regulation, lack of knowledge regarding the possible environmental impact of such an activity, as well as spatial conflicts with other traditional and emerging uses. Most of the coastal Member States have adopted Maritime Spatial Planning (MSP) as a fundamental tool for integrated and sustainable management of human activities in the marine environment. MSP is capable of definitively driving the use of offshore renewable facilities. Its proper application supports decision making, simplifies and accelerates the process of obtaining permits, improves compatibility of uses, integrates stakeholders in planning, prevents environmental deterioration of sensitive areas, enhances the availability of information and promotes cross-border co-operation. This paper aims to evaluate the influence of maritime spatial planning processes on the advance of blue energy within the framework of the European Union. The results show positive relationships between MSP and the development of offshore renewable energy in countries such as Germany, the Netherlands and the United Kingdom.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0308597X1830304X-fx1.jpg" width="477" alt="fx1" title="fx1"〉〈/figure〉〈/p〉〈/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: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 99〈/p〉 〈p〉Author(s): Bong-Tae Kim, Christopher L. Brown, Do-Hoon Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We assess the vulnerability to climate change of Korean aquaculture based on predicted changes in seawater temperature and salinity in adjacent sea areas of the Korean Peninsula according to representative concentration pathways (RCP) scenarios. Unlike previous studies that have been conducted mostly on a national scale, we classify 14 farming species in major production regions of the Republic of Korea, and assess their vulnerability for each region, using the indicator-based method and the Intergovernmental Panel on Climate Change's definition of vulnerability in order to overcome limitations in developing specific adaptation strategies within a country. First, for each exposure, sensitivity, and adaptive capacity, specific and proper indicators are selected. Subsequently, these indicators are estimated and weighted to analyze vulnerability to climate change. The results show that the absolute level of vulnerability is high in a long-term period of RCP8.5 in which exposure becomes severe, whereas the relative vulnerability is similar among farming species and regions. Specifically, vulnerability is at the highest level in seaweed, such as laver and sea mustard, while fish, shrimp, and abalone are relatively less vulnerable to climate change.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): X.Y. Wang, S.L. Zhang, S.D. Feng, L. Qi, R.P. Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The structures of the Ti〈sub〉75〈/sub〉Al〈sub〉25〈/sub〉 alloy during rapid-quenching with and without external pressure are investigated by using molecular dynamic techniques. The amorphous phase can be obtained at the cooling rate 10.0 K/ps without pressure. The alloy is composed of crystal and amorphous phase at the cooling rate 0.1 and 1.0 K/ps without pressure, but the pure amorphous phase can be formed when the pressure exceeds the critical value. The critical pressure is about 20 and 30 GPa when the cooling rate is 0.1 and 1.0 K/ps, respectively. H-A indices analysis indicates that high pressure favors the formation of the ideal icosahedral structures in the amorphous Ti〈sub〉75〈/sub〉Al〈sub〉25〈/sub〉 alloy, and the content of 1551 bond-type can reach near to 50% when the pressure is 30 GPa. The amorphous state can be maintained if the external pressure is removed from the alloy step-by-step. The content of 1551 bond-type decreases with the deceasing of the pressure, but the 1541 and 1431 bond-types increase in this process.〈/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: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): S.P. Sun, J.L. Zhu, S. Gu, X.P. Li, W.N. Lei, Y. Jiang, D.Q. Yi, G.H. Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The surface stability and equilibrium morphology of MoO〈sub〉3〈/sub〉 were investigated by the first principles calculations. The thermodynamic energies of the stoichiometric surfaces of MoO〈sub〉3〈/sub〉 are in the order (0 1 0) 〈 (1 0 1) 〈 (0 0 1) 〈 (1 0 0). It is found that the (0 1 0) surface has a lowest surface energy, which agrees well with the previous calculations. The energies of the non-stoichiometric surfaces were evaluated as functions of temperature and oxygen partial pressure. The results show that the energies of Mo-terminated surfaces decrease with temperatures, and increase with oxygen partial pressures, while the energies of O-terminated surfaces show the opposite rule. The equilibrium morphology of MoO〈sub〉3〈/sub〉 was predicted by using the Gibbs-Wulff model, and then was compared with the other’s experiments and theoretical results.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sanju Gupta, Nicholas Dimakis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interfacial interactions between transition metal oxides (vanadium oxide VO〈sub〉2〈/sub〉, vanadium pentoxide V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉, cobalt oxide CoO and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, manganese oxide MnO〈sub〉2〈/sub〉) and water adsorbates on graphene supports as solvated interfaces and influence of defects in graphene are studied using periodic density functional theory (DFT) calculations in view of their significance for applied electrochemistry. DFT complemented and synergized our experimental work. The optimized metal oxide adatom-graphene geometries identified the preferred adatom sites, whereas metal oxide-graphene strengths are correlated with the adatom distance from the graphene plane, the Metal-C overlap populations, and the adsorption energies. The presence of finite electronic density of states (DOS) near Fermi level and charge transfers between the adatom top layer and graphene supports reflect primarily covalent bonding nature. The presence of small orbital overlap integral of bonds between the s and p (and d) orbitals of the nearest carbon (graphene), carbon oxide (graphene oxide) and metal oxide atoms reveal localized orbital re-hybridization resulting in changes in DOS yielding high electrochemical activity. Moreover, for increased adatom coverage the extent of charge transfer reverses resulting in limited electroactivity. In fact, DFT calculations are corroborated with experimental findings, where graphene-based supports decorated with optimal mass loaded nanostructured Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 and MnO〈sub〉2〈/sub〉 (as well as V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉) were capable of delivering maximum specific energy storage capacity (C〈sub〉s〈/sub〉) 〉 550 F·g〈sup〉−1〈/sup〉 (Gupta et al. J. Mater. Res. 32, 301 (2017)) in contrast to higher or lower loading. The presence of defects in graphene materials results in new electronic states to endow unique functionalities that is not otherwise possible in the bulk and with adsorbed water molecules besides optimum C/O ratio in graphene oxide nanosheets that show redshift thus a decreasing bandgap and finite charge transfer from graphene to water molecules. The case examples studied in this work represent a first glimpse of what may become routine and integral step in materials design and discovery for alternative energy and sustainable environmental technologies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): Anne-Isabelle Bidegaray, Andrea Ceglia, Maria Rita Cicconi, Van-Thai Pham, Amandine Crabbé, El Amine Mernissi Cherigui, Karin Nys, Herman Terryn, Daniel R. Neuville, Stéphane Godet〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The analysis of iron, manganese and antimony in silicate glass is of great interest in chemistry, materials science, earth sciences and archaeological sciences. Yet, conclusions from different fields appear to be contradictory and many questions about redox reactions in glass remain. The purpose of this study is thus to discuss whether and how these multivalent elements interact in glass. Soda-lime silicate melts containing iron along with manganese and/or antimony have been analysed at different high temperatures under argon atmosphere. Using 〈em〉in-situ〈/em〉 XANES at the Fe K-edge, redox thermodynamics, kinetics and diffusivities have been assessed for the different compositions. The data obtained show that antimony is more efficient at oxidising iron compared to manganese at all temperatures. The oxidising power trend would thus be Sb 〉 Sb + Mn 〉 Mn. Furthermore, hypotheses on the formation of Fe-Mn complexes are also reported in glasses with stoichiometric proportions of iron and manganese. Based on the determination of redox diffusivities, it appears that presence of other multivalent elements does not significantly affect the iron redox mechanisms and that diffusivity is essentially controlled by the mobility of calcium.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): Wentao Zhang, Feng He, Junlin Xie, Xiaoqing Liu, De Fang, Hu Yang, Zhihong Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Glass ceramics from modified molten blast furnace (BF) slag were prepared. The crystallization behavior of the modified BF slag was characterized using differential thermal analysis (DTA), X-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The crystallization kinetics results indicated that the crystallization activation energy initially decreased and subsequently increased with increasing CaO/SiO〈sub〉2〈/sub〉. The crystallization temperature and the crystallization index (n) decreased from 916 to 867 °C, and 5.66–1.13, respectively. The crystallization mechanism transformed from bulk crystallization to surface crystallization. By XRD analyzing, Melilite was developed as the main crystal phase, and the transformation of crystal from akermanite to gehlenite was observed. The rapid surface crystallization was beneficial for maintaining the shape of glass ceramics. The complex replacement in melilite crystals resulted in the micro cracks in glass ceramics, therefore led to the decrease of flexural strength of glass ceramics〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): B.C. Jamalaiah〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different amounts of GeO〈sub〉2〈/sub〉 activated tellurite tungstate glasses were prepared by melt quenching technique. Thermal stability and glass forming ability were studied using differential scanning calorimetry. The chemical composition, homogeneity and amorphous nature of studied glasses were investigated. The phonon energy was estimated to be 721.34 cm〈sup〉−1〈/sup〉. Experimentally determined refractive indices were compared with those determined from optical band gap (E〈sub〉g〈/sub〉) and optical electronegativity (Δ〈em〉χ〈/em〉〈sup〉∗〈/sup〉). The dielectric constant (K) and electronic polarizability (α) were determined using refractive index value. The presence of disorder was estimated in terms of Urbach energy (E〈sub〉U〈/sub〉). The average electronegativity (〈em〉χ〈/em〉〈sub〉〈em〉ave〈/em〉〈/sub〉), oxide ion polarizability (〈em〉α〈/em〉〈sub〉〈em〉O〈/em〉〈/sub〉〈sup〉2−〈/sup〉) and covalent character (C〈sub〉cov〈/sub〉) were determined. The content of GeO〈sub〉2〈/sub〉 was optimized to be 10.0 mol% to design a novel host material for solid state lasers and fiber devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): Chunhe Jiang, Kejiang Li, Jianliang Zhang, Qinghua Qin, Zhengjian Liu, Minmin Sun, Ziming Wang, Wang Liang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉SiO〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-CaO-MgO is the most significant slag system in the blast furnace ironmaking process and it is very important to investigate the microstructure and viscosity of the system. In this paper, molecular dynamics simulations were carried out to explore the effects of MgO/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 ratio on structure and properties of the system. Based on the self-diffusion coefficients, the viscosities were calculated by Einstein-Stokes equation and compared with the experimental value and the Factsage value. The results showed that with the increase of MgO/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 ratio, the stability of [SiO〈sub〉4〈/sub〉]〈sup〉4−〈/sup〉 and [AlO〈sub〉4〈/sub〉]〈sup〉5−〈/sup〉 tetrahedron became weaken and the relative proportions of bridge and non-bridge oxygen showed a decrease. And due to the increase of MgO, more Mg〈sup〉2+〈/sup〉 ions are used as network modifiers to reduce the degree of polymerization of the system, resulting in a decrease in the viscosity, which is consistent with experimental results. Finally, based on the present study, in the case of increasing Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 content of blast furnace slag, the fluidity of slag could be adjusted by controlling MgO/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 ratio, thereby providing a basis for stable operation of blast furnace ironmaking.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): A.I. Popov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The definition of glassy state presented by the authors of the article “The glassy state of matter: Its definition and ultimate fate” E. Zanotto and J. Mauro is considered. The importance of the contribution to the glassy state problem made in the article is emphasized. At the same time consideration of the glassy state as unstable state of matter causes definite objections. It is more correctly to consider the glassy state as metastable state of matter.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): M.G. Syamala Rao, M.A. Pacheco-Zuñiga, L.A. Garcia-Cerda, G. Gutiérrez-Heredia, J.A. Torres Ochoa, M.A. Quevedo López, R. Ramírez-Bon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we developed a novel inorganic-organic hybrid gate dielectric by combining zirconium and hafnium components to form zirconium hafnium oxide strongly linked with polymethyl methacrylate (ZrHfO〈sub〉2〈/sub〉-PMMA) and deposited at low temperature (200 °C) by sol-gel method. The obtained 108 nm thick, high-quality hybrid gate dielectric showed an exceptionally low surface roughness (0.9-nm), a low leakage current density (7.7 × 10〈sup〉−6〈/sup〉 A/cm〈sup〉2〈/sup〉) and reasonable dielectric properties such as gate capacitance along with dielectric constant (77 nF/cm〈sup〉2〈/sup〉 & 9.4 @1 kHz) respectively. To examine the ZrHfO〈sub〉2〈/sub〉-PMMA hybrid dielectric electrical properties we constructed thin-film transistors (TFTs) with room temperature r.f sputtered n-type metal oxide semiconductors, a-IGZO and ZnO, as active channels. The bottom gate fabricated a-IGZO TFTs driving at as low as below 6 V, with extracted field effect mobility of 2.45 cm〈sup〉2〈/sup〉/V. s, a low threshold voltage of 1.2 V with large ON/OFF current ratio 10〈sup〉7〈/sup〉 respectively. On the other hand, for comparison we employed ZnO TFTs by applying same hybrid dielectric system, the obtained parameters of bottom gate ZnO TFTs were good field effect saturation mobility of 12.8 cm〈sup〉2〈/sup〉/V. s, threshold voltage of 1.8 V and ON/OFF current ratio of 10〈sup〉3〈/sup〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): Weidi Zhu, Mark Lockhart, Bruce Aitken, Sabyasachi Sen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The viscoelastic properties of supercooled As〈sub〉x〈/sub〉Se〈sub〉100-x〈/sub〉 (0 ≤ x ≤ 30) and As〈sub〉x〈/sub〉Se〈sub〉100-x-y〈/sub〉I〈sub〉y〈/sub〉 (x = 20, 30 and y = 10, 20) liquids are studied using oscillatory parallel plate rheometry. In addition to the α-relaxation process, the shear relaxation of liquids with selenium chains longer than ~ 3 atoms is also characterized by a low-frequency polymeric mode. The temporal decoupling of this low-frequency soft/floppy relaxation mode from that of the α-relaxation mode is a unique function of the average selenium chain length. The floppy mode abruptly vanishes for liquids with average chain lengths shorter than ~ 3 Se atoms, thus implying a dynamical rigidity transition. When taken together, these results indicate that, contrary to the conventional wisdom, the pertinent structural variable associated with such transition in the viscoelastic behavior is not the average coordination number but instead the intermediate-range structural elements such as the average selenium chain length.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): M.S.A. Mohd Saidi, S.K. Ghoshal, K. Hamzah, R. Arifin, M.F. Omar, M.K. Roslan, E.S. Sazali〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the influence of silver (Ag) and titania (TiO〈sub〉2〈/sub〉) nanoparticles (ATNPs) co-embedment on the photoluminescence (PL) properties of dysprosium ions (Dy〈sup〉3+〈/sup〉) doped zinc-magnesium tellurite glass system prepared using conventional melt quenching method. Both up- and down- converted PL spectra of glasses revealed three emission bands located at 482 (blue: 〈sup〉4〈/sup〉F〈sub〉9/2〈/sub〉 → 〈sup〉6〈/sup〉H〈sub〉15/2〈/sub〉), 574 (yellow: 〈sup〉4〈/sup〉F〈sub〉9/2〈/sub〉 → 〈sup〉6〈/sup〉H〈sub〉13/2〈/sub〉) and 664 nm (weak red: 〈sup〉4〈/sup〉F〈sub〉9/2〈/sub〉 → 〈sup〉6〈/sup〉H〈sub〉11/2〈/sub〉), where the band intensities were enhanced with the inclusion of ATNPs. Glasses with 0.2 mol% of ANPs and up to 0.3 mol% of TNPs disclosed highest PL intensity enhancement, which was majorly attributed to the ATNPs mediated localized surface plasmon resonance (LSPR) and large field enhancement (called hot spot) effects in the proximity of Dy〈sup〉3+〈/sup〉 ions. Absorption spectra of glasses displayed two plasmon bands characteristics of each type of nanoparticle. It was inferred that the superposition of localized SP modes from ATNPs could generate new hybridized modes (strong local field in the vicinity of Dy〈sup〉3+〈/sup〉 ions) shifted with respect to the single type of NPs resonance. HRTEM images showed the existence of both Ag and titania NPs inside the glass matrix. Glasses containing ATNPs exhibited anatase phase with (103) and (112) nanocrystalline lattice plane orientation. Proposed glass system may be useful for the development of solid state laser and photonic devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 474〈/p〉 〈p〉Author(s): Muhammad Arshad, M. Asghar, Muhammad Junaid, Muhammad Farooq Warsi, M. Naveed Rasheed, M. Hashim, M.A. Al-Maghrabi, Muhammad Azhar Khan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study Co-Ni co-doped nanocrystalline manganese ferrites were fabricated via co-precipitation method. The annealing of as prepared nanoferrites was done at 950 °C for 7 h. The powder X-ray diffraction (XRD) confirmed that all samples possessed cubic spinel structure. The crystallite size was determined by Scherrer’s equation that lies in the range of 27–35 nm. The spectral analysis confirmed bending and stretching of bonds at octahedral (B) and tetrahedral (A) sites. The spectral bands were shifted towards the longer wavelength side and these indicate the incorporation of dopants cations (Co-Ni). The magnetic parameters were measured from the M-H loops of nanoferrites. With the increase of Co-Ni contents, the saturation magnetization (Ms) increased up to x = 0.15 and then it decreased. The dielectric properties of all compositions were studied in 1 MHz–3 GHz range and were discussed in the light of Debye-type reduction phenomenon by following the Koop’s theory. The dielectric and magnetic behavior evaluation suggested that synthesized ferrites are suitable for microwave devices fabrication.〈/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-S0304885318319127-ga1.jpg" width="282" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Infrared Physics & Technology, Volume 96〈/p〉 〈p〉Author(s): Chunyan Guo, Yaoyao Sun, Qingxuan Jia, Zhi Jiang, Dongwei Jiang, Guowei Wang, Yingqiang Xu, Tao Wang, Jinshou Tian, Zhaoxin Wu, Zhichuan Niu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A kind of wide spectrum infrared detectors based on InAs/GaSb type-II superlattices (T2SLs) operating from 0.5 μm to 5 μm wavelength range is reported. The materials were grown by Molecular Beam Epitaxy (MBE) on GaSb substrates. Diverse types and sizes microstructure are fabricated on the surface of the detector to form the photon traps (PTs) array. PTs decrease the reflectivity and increase the light absorption of epitaxial material. Compared with the planar mesa detectors without antireflection (AR) film, detectors with PTs array exhibits a high responsivity of 0.86 A/W at 1160 nm and maximum D* reaches to 10〈sup〉9〈/sup〉 cm Hz〈sup〉1/2〈/sup〉/W in visible wavelength. Also, the PTs processed on detector augment spectral response and QE in infrared wavelength. The peak responsivity of the detector with PTs is to 1.35 A/W and QE can exceed to 0.76 in the infrared wavelength. The infrared detector with PTs is attractive for numerous applications.〈/p〉〈/div〉 〈/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: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry, Volume 128〈/p〉 〈p〉Author(s): J.M. Kranabetter〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Forest floor carbon (C) sequestration has been negatively correlated with manganese (Mn) availability, possibly due to reduced efficacy of Mn-peridoxase enzymes produced by Agaricomycete fungi. I examined a soil C and Mn dataset from a podzolization gradient, along with fungal sporocarp Mn concentrations, to potentially corroborate this finding. An inverse power relationship between soil C and soil Mn content across temperate rainforests was confirmed, which provides further evidence of a Mn bottleneck in C turnover. Average Mn concentrations of saprotrophic sporocarps were greater than those of ectomycorrhizal fungi, and displayed a similar inverse correlation with increasing soil C. The absence or limited effectiveness of select saprotrophic fungi across Mn-depleted forest soils may be one mechanism behind impeded turnover of recalcitrant organic matter.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry, Volume 128〈/p〉 〈p〉Author(s): Charles R. Warren〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phospholipids are isolated from crude lipid extracts by silica solid phase extraction (SPE), but for soils we don't know if phospholipids are the only fatty acid-based lipids present in the polar lipid fraction. Lipids extracted from three soils were fractionated with a silica SPE protocol commonly used for soils, with “neutrals” eluted by chloroform, “glycolipids” eluted by acetone, and “phospholipids” eluted by methanol. Fatty acid-based lipids were identified and quantified by liquid chromatography-mass spectrometry. Phospholipids were recovered in the methanol fraction, but this fraction also included betaine lipids. In two soils the methanol fraction was 3–6% betaine lipid while in one soil betaine lipids accounted for 48% of lipids in the methanol fraction. Clearly the fraction obtained by eluting lipids from silica with methanol is not purely phospholipid but can contain significant amounts of other polar lipids.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Xu Wu, Yalin Feng, Yali Du, Xuezhen Liu, Chunlei Zou, Zhe Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉LDHs templates (marked as CoAl-MnO〈sub〉2〈/sub〉-LDH and CoMnAl-CO〈sub〉3〈/sub〉-LDH) were fabricated via ion-exchange/redox reaction and hexamethylenetetramine (HMT) hydrolysis methods respectively. CoMnAl mixed metal oxides (marked as MnO〈sub〉2〈/sub〉/CoAl-LDO and CoMnAl-LDO) from the as-prepared LDHs templates were novelly prepared and tested as low-temperature NH〈sub〉3〈/sub〉-SCR catalysts. Catalytic evaluation pronouncedly affirmed that the catalytic performances of the as-acquired catalysts were vulnerable to the preparation method of precursor template, where MnO〈sub〉2〈/sub〉/CoAl-LDO presented preferable DeNOx activity (over 90% NOx conversion), N〈sub〉2〈/sub〉 selectivity and SO〈sub〉2〈/sub〉 resistance in much broader working temperature window (90–300 °C) than CoMnAl-LDO. Multiple characterizations revealed that the excellent catalytic performance of the MnO〈sub〉2〈/sub〉/CoAl-LDO could be attributed to its higher specific surface area which could promote dispersion of abundant Mn〈sup〉4+〈/sup〉 and Co〈sup〉3+〈/sup〉 species, and resultantly afforded stronger redox ability and more acid sites. Moreover, dynamic calculation confirmed that the relatively lower activation energy on MnO〈sub〉2〈/sub〉/CoAl-LDO for low-temperature NH〈sub〉3〈/sub〉-SCR reaction should be closely related to the occurrence of a more rapid redox cycle and in agreement with the excellent DeNOx performance.〈/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-S0169433218329702-ga1.jpg" width="413" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sandra Jendrzej, Leonard Gondecki, Jörg Debus, Henning Moldenhauer, Peter Tenberge, Stephan Barcikowski, Bilal Gökce〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The lubricant is a central element in the transmission design. It primarily separates the two contact partners through a pressure-induced solidification in the lubrication gap, thus enabling the operation of heavily loaded sliding-rolling contacts. On the one hand, the quality and properties of a lubricant depend on the base oils, which differ by their viscosity and process-technological parameters. The addition of particulate additives gives the lubricants further functional properties that are not contained in the base oil. In this study, the influence of laser-synthesized yttria-stabilized zirconia nano- or submicrometer spheres as dispersed functional elements in the lubricant is studied, and their impact on wear and fatigue on the tooth flank is investigated. The work includes systematic investigations on the influence of the particle’s shape and size by running tests on a FZG gear test rig. Finally, the potential of the laser-generated particles as a lubricant additive is evaluated in a first conclusion.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Nuclear Materials, Volume 513〈/p〉 〈p〉Author(s): Matic Pečovnik, Sabina Markelj, Anže Založnik, Thomas Schwarz-Selinger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The influence of grain size on deuterium transport and retention in tungsten was studied. For this purpose an experiment was carried out on three polycrystalline tungsten samples with different grain sizes and a single crystal sample with surface orientation 〈100〉. In order to increase deuterium retention and hence the sensitivity for detection, samples were first damaged by high energy W ions. After damaging, the samples were exposed to a flux of deuterium atoms at 600 K for 70 h. During the exposure the depth profile of the retained deuterium was measured by Nuclear Reaction Analysis using a 〈sup〉3〈/sup〉He ion beam. After the exposure the samples were also analysed by Thermal Desorption Spectroscopy. A clear difference in the time dependence of deuterium uptake was noticed between different samples. The experimental results were modeled using a rate-equation model. The influence of different grain size was modeled by changing the effective height of the potential barrier for deuterium atoms to enter into the bulk. We managed to successfully describe the transport of deuterium into the bulk of tungsten by reducing the potential barrier for samples with smaller grain sizes while the barrier for the sample with larger grain size was close to the value for the damaged single crystal sample.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0022311518307256-fx1.jpg" width="256" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Nuclear Materials, Volume 513〈/p〉 〈p〉Author(s): P.A. Burr, E. Kardoulaki, R. Holmes, S.C. Middleburgh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stability, diffusivity and clustering behaviour of defects in uranium diboride (UB〈sub〉2〈/sub〉) was investigated in light of the potential application as a burnable absorber in nuclear fuel. UB〈sub〉2〈/sub〉 was found to accommodate limited deviations from stoichiometry, which should be a consideration when manufacturing and operating the material. Self-diffusivity of both U and B was found to be sluggish (10〈sup〉−14〈/sup〉 cm〈sup〉2〈/sup〉/s for B and 10〈sup〉−19〈/sup〉 cm〈sup〉2〈/sup〉/s for U at 2000K) and highly anisotropic, with migration along the basal planes being orders of magnitude faster than 〈em〉c〈/em〉-axis migration. The anisotropy of defect migration (both interstitials and vacancies) is predicted to hinder recombination of defects produced by collision cascades, thus limiting the radiation tolerance of the material. Boron and uranium vacancies exhibit a drive to cluster. Boron vacancies in particular, which are mobile on basal planes, are predicted to cluster into strongly bound di-vacancy, which in turn are less mobile. These are then predicted to grow into larger two-dimensional vacancy clusters on the B plane, leading to anisotropic swelling. We provide an analytical expression to predict the stability of these clusters based on purely geometrical considerations. Finally, the accommodation of Li, He and Xe onto vacancy clusters was considered. Li appears to stabilise the structure upon U depletion, while the retention of He and Xe appears to rise with increasing B depletion, through the formation of vacancy clusters.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Physica B: Condensed Matter, Volume 554〈/p〉 〈p〉Author(s): D. Bessas, I. Kantor, D. Bourazani, K. Georgalas, N. Biniskos, L. Zhang, A.I. Dugulan, E. Syskakis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bulk Sr〈sub〉2〈/sub〉PdO〈sub〉3〈/sub〉 was synthesized by a modified solid state reaction and a detailed characterization was carried out using both microscopic and macroscopic experimental techniques. Pd site exhibits an electric field gradient of 5.9(1) ⋅ 10〈sup〉17〈/sup〉 V/cm〈sup〉2〈/sup〉 due to the anisotropic local atomic configuration. A Curie - paramagnetic susceptibility indicating antiferromagnetic interactions superimposed to a core diamagnetic state is confirmed. A linear volume thermal expansion with a coefficient of 3.0(1) ⋅ 10〈sup〉−5〈/sup〉 K〈sup〉−1〈/sup〉 at room temperature is extracted. A collection of Einstein oscillators, with an Einstein temperature of about 115 K, is involved in the thermal transport. Large atomic displacements were observed in Sr vibrations. No Pd or Sr valence change is observed up to 900 K. A moderate anharmonicity is identified and quantified in a macroscopic Grüneisen parameter of 2.5(1) at room temperature. The electrical resistivity reveals a semiconducting behaviour. A systematic reduction in electrical resistivity and a change in the conduction mechanism is observed upon thermal cycling which indicates that a peculiar electronic mechanism is involved.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Monzani, A. Andreazza, M. Citterio, P. Fontana, M. Ianna, T. Lari, V. Liberali, F. Ragusa, C. Sbarra, A. Sidoti, A. Stabile〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Monochromatic X and gamma rays are a standard calibration tool for semiconductor detector. For finely segmented pixel detectors, like the ones foreseen for HL-LHC detector upgrades, the single pixel spectrum is affected by charge sharing across nearby pixels, due to diffusion and the finite range of photoelectrons, resulting in a low energy continuum below the photoelectric peak. In this paper a systematic simulation study will be presented. The shape of the transition between the photoelectric peak and the continuum is determined by diffusion and needs to be unfolded for a correct estimation of the energy resolution. Simulation results are compared with data collected with different high-resistivity CMOS devices with 50 × 250 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi mathvariant="normal"〉μ〈/mi〉〈/math〉m〈sup〉2〈/sup〉 pixel size and photon energies between 13 and 60 keV. They show a good agreement, highlighting the potential usage of the whole single pixel spectrum to derive device characteristics.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 501〈/p〉 〈p〉Author(s): G. Gorni, M.J. Pascual, A. Caballero, J.J. Velázquez, J. Mosa, Y. Castro, A. Durán〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The crystallization mechanism of LaF〈sub〉3〈/sub〉 in sol-gel oxyfluoride glass-ceramics in the system SiO〈sub〉2〈/sub〉-LaF〈sub〉3〈/sub〉 has been studied using DTA, XRD, FTIR, HRTEM and NMR. Based on classical calculations of non-isothermal DTA curves involving Ozawas's plots, a diffusion-controlled process should be responsible for the fluorides crystallization similarly to that obtained for melt-quenching oxyfluoride glass-ceramics. Therefore, an increase of the crystal size and fraction is expected when increasing the time and/or temperature of the treatment. Nevertheless, XRD, FIR, HRTEM and NMR demonstrated that neither bigger crystals nor higher crystal fraction are obtained for treatment times longer than 1 min at 550 °C. However, further heat treatment causes that the structural order of the crystals is lost. On the other hand, typical fluorides crystallization temperatures (~300 °C) in sol-gel materials are much lower than T〈sub〉g〈/sub〉 of the matrix (~1130 °C) thus being very different to what observed for oxyfluoride glasses prepared by melt-quenching. The proposed crystallization mechanism is a fast process that occurs when crystallization temperature is reached. This behavior is explained as a chemical reaction from the xerogels, followed by the fast precipitation of the nanocrystals without energy barrier. The nanocrystals are unstable in the surrounding SiO〈sub〉2〈/sub〉 matrix for aging at crystallization or higher temperatures. These treatments lead to a dissolution process, favored by the compositional gradient between matrix and crystals, which drive the material to reach the equilibrium.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 501〈/p〉 〈p〉Author(s): Jürn W.P. Schmelzer, Alexander S. Abyzov, Vladimir M. Fokin, Christoph Schick〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉General relations for the dependence of the thermodynamic driving force of crystallization and the specific interfacial energy melt-crystal of critical crystal clusters on temperature and pressure are derived. Its application to the analysis of experimental data on crystal nucleation seems to support at a first glance a proposal by Kauzmann on the existence of a pseudo-spinodal curve in melt-crystallization. Provided this assumption is true, Kauzmann temperature (and for pressure-induced nucleation, the Kauzmann pressure) cannot be reached by a metastable liquid due to intensive crystallization processes occurring in its vicinity. However, such suggestion cannot be retained taking into account the kinetic terms (diffusion coefficients, viscosity) in the expression for the nucleation rate. The absence of a pseudo-spinodal in melt-crystallization can be verified also in an alternative way by considering the characteristic time scales of crystallization and relaxation. Finally, it is shown that the phenomenon denoted commonly as Kauzmann paradox is merely an untypical as compared to normal conditions type of behavior. Neither in its original formulation nor in its consequences it results in any contradictions with basic laws of nature. They are prevented either by normal (not associated with a pseudo-spinodal) crystallization or a conventional glass transition.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 501〈/p〉 〈p〉Author(s): J. Gilabert, M.P. Gómez-Tena, V. Sanz, S. Mestre〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The effect of a post-synthesis thermal treatment on CoCr〈sub〉2−2Ψ〈/sub〉Al〈sub〉2Ψ〈/sub〉O〈sub〉4〈/sub〉 (0.0 ≤ Ψ ≤ 1.0) ceramic pigments synthesized by Solution Combustion Synthesis (SCS) has been studied. As-synthesized SCS pigments were treated at two different calcination temperatures (800 °C and 1000 °C) to study changes in mineralogy, microstructure and thermal behaviour, as well as their effect over the colouring power.〈/p〉 〈p〉Spinel-type 〈em〉Fd〈/em〉-3〈em〉m〈/em〉 crystalline structure was developed in all cases. Nevertheless, crystallinity parameters were highly affected by both analysed processing parameters: composition (Ψ) and post-synthesis calcination temperature (T〈sub〉c〈/sub〉). A Cr(III) enrichment along with T〈sub〉c〈/sub〉 increase favoured ion rearrangement to promote sample crystallization and crystallite growth. Fast kinetics of SCS makes Al-rich spinels with transition metals difficult to be synthesized. The application of a secondary thermal treatment resulted in a favourable evolution towards a well-crystallized structure. Lattice parameter did not seem to be affected by T〈sub〉c〈/sub〉, although it evolved indeed with composition. From a microstructural point of view, as-synthesized pigments were foamy, with a very low bulk density and nanometric grain size. After the thermal treatment, larger grain sizes were obtained, especially for the samples richer in Al and treated at higher T〈sub〉c〈/sub〉.〈/p〉 〈p〉All pigments developed intense colours in a transparent glaze without showing heterogeneities, indicating a stable behaviour against glazing process. Glaze colour evolved from green to perfectly blue shades, indicating an important dependence on composition. Nevertheless, colouring power seemed to be rather affected by calcination process.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Radiation Measurements, Volume 119〈/p〉 〈p〉Author(s): Alessio Parisi, Luana de Freitas Nascimento, Olivier Van Hoey, Patrice Mégret, Hisashi Kitamura, Satoshi Kodaira, Filip Vanhavere〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lithium fluoride thermoluminescent radiation detectors with different dopant concentrations (〈sup〉7〈/sup〉LiF:Mg,Ti and 〈sup〉7〈/sup〉LiF:Mg,Cu,P) were exposed to 〈sup〉1〈/sup〉H and 〈sup〉4〈/sup〉He ions at the Heavy Ion Medical Accelerator in Chiba (HIMAC) in order to investigate their response to energetic light charged particles. Computer simulations with the Monte Carlo code PHITS were performed for a better interpretation of the experimental data. The results were compared with literature efficiency data and with the results of a recently developed microdosimetric efficiency model. In case of the main peak signal of 〈sup〉7〈/sup〉LiF:Mg,Ti detectors, the determined efficiency values are in good agreement with previous investigations. Discrepancies in the efficiency of high temperature signal due to well-known non-linearity effects are reported. For 〈sup〉7〈/sup〉LiF:Mg,Cu,P detectors, an anomalous thermoluminescence behavior in the low temperature part of the signal was found and discussed. Depending on the light quantification process, differences up to 30% in the dose assessment can be obtained, affecting also the relative efficiency determination process. An explanation of this phenomenon as a consequence of local migration of the charged carriers between the low temperature peaks and the main peak is presented. The implications of these findings on the use of LiF:Mg,Cu,P detectors in radiation environments characterized by the presence of 〈sup〉1〈/sup〉H and 〈sup〉4〈/sup〉He ions (i.e. space and proton therapy) are discussed. In order to avoid the occurrence of this anomalous behavior, it is advised to pre-heat the detectors after energetic light particle exposures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): Vladimir A. Osinov, Stylianos Chrisopoulos, Theodoros Triantafyllidis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The paper presents a numerical analysis of the dynamic deformation of the tunnel lining and the soil caused by a blast-induced pressure pulse of a moderate amplitude (several megapascals) inside the tunnel. The tunnel lining is circular and consists of individual concrete linearly elastic tubbings. The tunnel is located at a depth of 15 m in fully saturated granular soil. Effective-stress changes are described by a hypoplasticity model. The possibility of pore water cavitation at zero absolute pore pressure is taken into account. The problem is solved in a two-dimensional plane-strain formulation with the finite-element program Abaqus/Standard. Emphasis is placed on fine spatial discretization in order to obtain accurate solutions. Stresses and deformations in the lining and in the soil are analysed in detail. The solutions reveal an important role of the strong nonlinearity in the soil behaviour due to the pore water cavitation.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 514〈/p〉 〈p〉Author(s): Mahasin Ali Khan, Meghma Bera, Robert A. Spicer, Teresa E.V. Spicer, Subir Bera〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fossil leaf floras, from the latest Miocene-Pliocene Siwalik Group exposed in Bhutan, sub-Himalaya, are subjected to a CLAMP (Climate Leaf Analysis Multivariate Program) analysis using a high-resolution gridded climate calibration. The CLAMP analysis of 27 different morphotypes of fossil leaves indicates a mean annual temperature (MAT) of 24.1 °C ± 2.8 °C; a cold month mean temperature (CMMT) of 18.9 °C ± 4 °C and a warm month mean temperature (WMMT) of 27.8 °C ± 3.3 °C. The analysis also suggests a weak monsoonal climate (the monsoon index, MSI 46.7; present MSI 52) with growing season precipitation (GSP) of 1819 ± 916 mm (present GSP 2490 mm). Here we also compare palaeoclimate estimates of the latest Miocene-Pliocene Siwalik Group flora from Bhutan (c. 6 to 3.8 Ma) with those of previously investigated Siwalik Group floras from the Miocene-Pleistocene of Arunachal, India and Miocene Siwalik floras of Darjeeling, India which characterise the monsoon signature at the time of deposition. Since all the Siwalik floras of the eastern Himalaya (Darjeeling and Arunachal Pradesh) spanning the mid-Miocene to Pleistocene yield almost the same values we suggest that overall the eastern Himalayan Siwalik climate appears to have been remarkably uniform over the past 15 million years. The MAT result of the Bhutan Siwalik flora differs by just 0.6 °C from Arunachal and 1.2 °C from Darjeeling Siwalik floras. For all Siwalik fossil assemblages, WMMTs, CMMTs and LGSs (length of the growing season) are similar and consistent (WMMTs around 28 °C, CMMTs around 18 °C and LGSs around 12 months). Similarly, the mean annual relative humidity (RH) and specific humidity (SH) appear to have been uniformly around 80% and 14 g/kg respectively throughout the Neogene of the eastern Himalayan Siwaliks. Changes in the monsoon index suggest that in both Bhutan and Arunachal sub-Himalaya, there has been little change in the intensity of the monsoon since mid-Miocene time, while further west in the Darjeeling area precipitation seasonality has increased since the mid-Miocene.〈/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-S0031018218303523-ga1.jpg" width="327" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 337〈/p〉 〈p〉Author(s): R. Calvelo Pereira, M. Camps Arbestain, F.M. Kelliher, B.K.G. Theng, S.R. McNally, F. Macías, F. Guitián〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have investigated the effect of supercritical drying (SD) on the porosity and the BET-N〈sub〉2〈/sub〉 specific surface area (SSA) of five allophane-rich and three non-allophanic topsoils. The contribution of organic matter (OM) and short-range ordered (SRO) constituents to the nanoscale porosity (〈100 nm size) and SSA was also evaluated following chemical treatments to oxidise OM and then remove the SRO phase. The average pore volume and SSA of the soils, measured after SD, are greater than the values obtained after air drying. For soils that are rich in SRO constituents, oxidation of OM leads to an increase in SSA. This observation is attributed to the unblocking of pore necks previously covered by OM, while the subsequent removal of SRO constituents causes a sharp decrease in SSA. The SRO constituents containing oxalate-extractable Al, are the major contributors to the SSA of the inorganic fraction. Besides confirming that SD can help preserve the nanoscale porosity of allophane-rich soils, the results highlight the contribution of SRO constituents to the SSA of soils and their ability to accumulate OM.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 501〈/p〉 〈p〉Author(s): Joanna Pisarska, Marta Sołtys, Joanna Janek, Agata Górny, Ewa Pietrasik, Tomasz Goryczka, Wojciech A. Pisarski〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxyfluoride lead-based and lead-free germanate glasses were heat-treated in order to fabricate transparent glass-ceramics. Cubic β-PbF〈sub〉2〈/sub〉 nanocrystals are well formed during crystallization of lead germanate glass. The up-conversion luminescence spectra of Er〈sup〉3+〈/sup〉 ions in lead germanate glass-ceramic system are enhanced significantly due to partial incorporation of the optically active ions into fluoride crystalline phase. These effects are not significant in oxyfluoride lead-free germanate glass after heat treatment process. The crystallization of barium gallo-germanate glass with BaF〈sub〉2〈/sub〉 is more complex and the presence of four crystalline phases BaF〈sub〉2〈/sub〉, BaO, Ba〈sub〉3〈/sub〉Ga〈sub〉2〈/sub〉Ge〈sub〉4〈/sub〉O〈sub〉14〈/sub〉 and GeO〈sub〉2〈/sub〉 was verified by X-ray diffraction measurements.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Thin Solid Films, Volume 669〈/p〉 〈p〉Author(s): Hirokazu Chiba, Rikyu Ikariyama, Shintaro Yasui, Hiroshi Funakubo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bismuth ruthenate (Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉) thin films were deposited on (111) yttria-stabilized zirconia (YSZ) single crystals and (111)YSZ//(111)Si substrates by chemical vapor deposition using Bi(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉[2-(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉NCH〈sub〉2〈/sub〉C〈sub〉6〈/sub〉H〈sub〉4〈/sub〉] and Ru(C〈sub〉7〈/sub〉H〈sub〉11〈/sub〉)(C〈sub〉7〈/sub〉H〈sub〉9〈/sub〉) as source materials and oxygen as a reactant gas. The film composition and X-ray diffraction 〈em〉ω〈/em〉-2〈em〉θ〈/em〉 scan profiles for thin films deposited using various source flow rate ratios revealed the existence of a process window to obtain stoichiometric Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉. Within the process window, the kind of substrates did not strongly affect the deposition rates of Bi and Ru or the Bi/Ru ratio of the deposited films. It was also confirmed that the Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 thin films grew epitaxially on both substrates within the process window. In particular, epitaxial Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 thin films grew on the Si substrate with a YSZ buffer layer. Scanning electron microscopy revealed the formation of continuous dense Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 films without any cracks or voids, and a relatively smooth interface between Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 and the YSZ buffer layer on Si. The resistivity of the Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 films was almost constant (~550 and ~950 μΩcm for the films deposited on (111)YSZ single-crystal substrates and (111)YSZ//(111)Si substrates, respectively), even when the ratio of Bi and Ru source gas flow rates was changed in the process window. In addition, the resistivity of Bi〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 films prepared on both kinds of substrates was almost independent of temperature from 10 to 300 K.〈/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: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Thin Solid Films, Volume 669〈/p〉 〈p〉Author(s): Hiroaki Uchiyama, Takahiro Bando, Hiromitsu Kozuka〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Titania (TiO〈sub〉2〈/sub〉) films were prepared from Ti(OC〈sub〉3〈/sub〉H〈sub〉7〈/sub〉〈sup〉〈em〉i〈/em〉〈/sup〉)〈sub〉4〈/sub〉 solutions of molar compositions, Ti(OC〈sub〉3〈/sub〉H〈sub〉7〈/sub〉〈sup〉〈em〉i〈/em〉〈/sup〉)〈sub〉4〈/sub〉: H〈sub〉2〈/sub〉O: HNO〈sub〉3〈/sub〉: C〈sub〉2〈/sub〉H〈sub〉5〈/sub〉OH = 1: 〈em〉x〈/em〉: 〈em〉y〈/em〉: 10 (〈em〉x〈/em〉 = 1.0–8.0, 〈em〉y〈/em〉 = 0.1–2.0), and the influence of the amount of H〈sub〉2〈/sub〉O and HNO〈sub〉3〈/sub〉 on the crystallization of the films during the heat treatment was investigated. The precipitation in the coating solutions containing a large amount of H〈sub〉2〈/sub〉O over 〈em〉x〈/em〉 = 4.0 was suppressed with increasing HNO〈sub〉3〈/sub〉 contents over 〈em〉y〈/em〉 = 1.0, where the H〈sub〉2〈/sub〉O contents in the solutions was able to be changed in the range of 〈em〉x〈/em〉 = 1.0–8.0. The increase in the H〈sub〉2〈/sub〉O contents led to the increase in the degree of crystallization, crystallite size and reflective index of the resultant TiO〈sub〉2〈/sub〉 films, while it decreased the size of the grains that were observed in the scanning electron microscope images. Anatase films with a higher refractive index of ca. 2.25 was obtained at 〈em〉x〈/em〉 = 8.0 and 〈em〉y〈/em〉 = 1.0–2.0.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 186〈/p〉 〈p〉Author(s): Márcio R. Nunes, Eloy A. Pauletto, José E. Denardin, Luis E.A. S. Suzuki, Harold M. van Es〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tillage and no-tillage result in different soil mechanical responses which in turn may affect crop growth. Better understanding of soil compressive behavior, therefore, is relevant for the assessment of tillage practices in agricultural systems. We studied the change in soil compressive properties and their relationship with soil physical attributes and plant growth through a chisel tillage chronosequence in a Nitisol where soil was untilled after chiseling for 24 months, 18 months, 12 months, 6 months, and zero months, and was under continuous (12-year) NT. The effects were measured for three soil depth layers: 0 to 7-cm, 7 to 17-cm and 20 to 30-cm. Mechanical chiseling was found to reduce both the degree of compactness and the pre-compression pressure compared to continuous NT, but made the soil more susceptible to new compaction. The effects of chisel tillage generally persisted for a period of 12–24 months. The degree of compactness and soil pre-compression pressure were found to be strongly correlated, and were strongly correlated with other soil physical attributes (soil penetration resistance, soil macroporosity, and soil aggregate stability). They were negatively correlated with root length, root density, and root volume, as well as stalk diameter, linking soil structure indicators to plant growth. Our results also showed that soil compressive parameter values can be estimated based on other soil physical properties that influence plant growth. These findings have potential for studies of crop response to soil structure and soil compaction and could be used to aid in choosing optimal soil management practices, in order to reduce the risk of soil compaction, linking soil compressive behavior and soil physical conditions to plant growth.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Cong Chen, Shouzhen Bao, Baoshun Zhang, Ying Chen, Wen Chen, Chengyu Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To reduce electromagnetic interference (EMI) and irradiation, one efficient path is to develop electromagnetic absorption (EMA) material with the aim of high-efficient convert electromagnetic wave into thermal energy. Presently strategy to design high-performance electromagnetic absorber is followed by the way of component optimization and microstructure design. This research reported an advanced HWCNTs/Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 ternary absorber, which was fabricated by decorating H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 treated carbon nanotubes (HCNTs) with magnetic core-shell shaped Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles. This HCNTs/Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 composite exhibits various electromagnetic loss forms, including conductive, dipole, interface loss 〈em〉etc〈/em〉. which attribute to EMA ability. The largest qualified frequency width (〈em〉f〈sub〉E〈/sub〉〈/em〉) can up to 5.4 GHz with a thickness of 1.5 mm. To discuss the EMA loss mechanism, control experiments have been conducted by preparation of Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, HCNTs@Fe@Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 composites. In this way, the attenuation mechanism can be better understood.〈/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-S0169433218329179-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): 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: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 379〈/p〉 〈p〉Author(s): Takashi Shiroto, Naofumi Ohnishi, Yasuhiko Sentoku〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For more than half a century, most of the plasma scientists have encountered a violation of the conservation laws of charge, momentum, and energy whenever they have numerically solved the first-principle equations of kinetic plasmas, such as the relativistic Vlasov–Maxwell system. This fatal problem is brought by the fact that both the Vlasov and Maxwell equations are indirectly associated with the conservation laws by means of some mathematical manipulations. Here we propose a quadratic conservative scheme, which can strictly maintain the conservation laws by discretizing the relativistic Vlasov–Maxwell system. A discrete product rule and summation-by-parts are the key players in the construction of the quadratic conservative scheme. Numerical experiments of the relativistic two-stream instability and relativistic Weibel instability prove the validity of our computational theory, and the proposed strategy will open the doors to the first-principle studies of mesoscopic and macroscopic plasma physics.〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Surface Science, Volume 681〈/p〉 〈p〉Author(s): Xuejiang Chen, Yuan Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Stepped morphologies on vicinal 3C- and 4H-SiC (0001) surfaces with the miscut toward 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mo〉[〈/mo〉〈mn〉1〈/mn〉〈mover〉〈mn〉1〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈mn〉00〈/mn〉〈mo〉]〈/mo〉〈/mrow〉〈/math〉 or 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mrow〉〈mo〉[〈/mo〉〈mn〉11〈/mn〉〈mover〉〈mn〉2〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈mn〉0〈/mn〉〈mo〉]〈/mo〉〈/mrow〉〈/math〉 directions have been studied with a three-dimensional kinetic Monte Carlo model. In the model, a three-dimensional lattice mesh was established based on the crystal lattice of 3C-and 4H-SiC to fix the positions of atoms and interatomic bonding. Periodic boundary conditions were applied in the lateral direction while helicoidal boundary conditions were used in the direction of crystal growth. Events, such as adatoms attachment, detachment and interlayer transport at the step edges, and adatoms adsorption and diffusion on the terraces were considered in the model. Effects of Ehrlich–Schwoebel barriers at downward step edges and incorporation barriers at upwards step edges were also considered. Moreover, the atoms of silicon and carbon were treated as the minimal diffusing species independently to achieve more elaborate information for the behavior of atoms in the crystal surface. The simulation results showed that multiple-height steps were formed on the vicinal 4H-SiC (0001) surfaces, whereas single bilayer-height stepped morphologies were observed on the vicinal 3C-SiC (0001) surfaces. Furthermore, zigzag shaped edges were observed for both of 3C- and 4H-SiC (0001) surfaces with the miscut toward 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mrow〉〈mo〉[〈/mo〉〈mn〉11〈/mn〉〈mover〉〈mn〉2〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈mn〉0〈/mn〉〈mo〉]〈/mo〉〈/mrow〉〈/math〉 direction. At last, the formation mechanism of the stepped morphology was also analyzed.〈/p〉〈/div〉 〈h5〉Graphical abstracts〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0039602818304618-fx1.jpg" width="301" alt="Image, graphical abstract" title="Image, graphical abstract"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 3 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Sound and Vibration, Volume 442〈/p〉 〈p〉Author(s): Jie Zhang, Edwin Reynders, Guido De Roeck, Geert Lombaert〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Many civil engineering structures have a repetitive or quasi-periodic geometry. Such structures have clustered modes with closely spaced natural frequencies corresponding to mode shapes with similar wavelengths. Such modes may be difficult to distinguish in modal tests and lead to difficulties when pairing calculated and experimentally determined modal characteristics in vibration-based model updating. For repetitive structures, the free wave characteristics, i.e. propagation constants and free waves, can be used alternatively to characterize their dynamic behaviour. The free wave characteristics can therefore be used instead of modal characteristics as data features in model updating of repetitive structures. This paper investigates the feasibility of model updating of repetitive structures based on free wave characteristics. First, the identification of the free wave characteristics from the measured vibration responses of a periodic structure is investigated. A stabilization diagram is constructed to pick up the stable free waves. Second, model updating of repetitive structures is performed through a match of the calculated and experimentally identified free wave characteristics. A least-squares cost function is formulated and minimized using a gradient-based optimization algorithm. This algorithm requires the sensitivity of the free wave characteristics to the model parameters that need to be updated. The analytical expressions for the free wave sensitivities are therefore derived. The proposed model updating procedure is demonstrated and validated by a numerical case study involving a repetitive frame structure and by an experiment on a four-storey steel frame structure. The results confirm the feasibility of model updating based on free wave characteristics for repetitive structures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 3 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Sound and Vibration, Volume 442〈/p〉 〈p〉Author(s): Timo Theurich, Johann Gross, Malte Krack〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A linear vibration absorber can be tuned to effectively suppress the resonance of a particular vibration mode. It relies on the targeted energy transfer into the absorber within a narrow and fixed frequency band. Nonlinear energy sinks (NES) have a similar working principle. They are effective in a much wider frequency band but generally only in a limited range of excitation levels. To design NES, their working principle must be thoroughly understood. We consider a particular type of NES, a small mass undergoing impacts and dry friction within a cavity of a base structure (vibro-impact NES or impact absorber). The nonlinear dynamic regimes under near-resonant forcing and resulting operating ranges are first revisited. We then investigate how off-resonant vibration modes and dissipation via impacts and dry friction contribute to the vibration suppression. Moreover, we assess the effectiveness of the impact absorber for suppressing multiple resonances in comparison to a linear tuned vibration absorber (LTVA) and a pure friction damper with the same mass.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 3 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Sound and Vibration, Volume 442〈/p〉 〈p〉Author(s): Arian Bahrami〈/p〉

Description: 〈p〉Publication date: 3 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Sound and Vibration, Volume 442〈/p〉 〈p〉Author(s): Chuan-Xing Bi, Yuan Liu, Yong-Bin Zhang, Liang Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The equivalent source method (ESM)-based sound field separation technique has been successfully introduced into near-field acoustic holography as a preprocessing tool to eliminate the influence of disturbing sources or reflections from the opposite side of the array. In this paper, that technique is further extended in a sparsity framework, which makes it possible to take the advantage of the theory of compressive sensing to achieve reasonable separation accuracy with a limited number of spatial sampling points. In this study, three sparse bases are considered, including two existing bases that are suitable for spatially sparse and spatially extended sources, respectively, and a more flexible, redundant sparse basis that is constructed by combining the two sparse bases above, and the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msub〉〈mi〉ℓ〈/mi〉〈mn〉1〈/mn〉〈/msub〉〈mo〉-〈/mo〉〈mtext〉norm〈/mtext〉〈/mrow〉〈/math〉 minimization is used to promote sparse solutions. Numerical simulation and experimental results demonstrate the validity of the proposed technique and show the superiority of the use of the redundant sparse basis. Besides, the effects of the relative strength of the target source to the disturbing source, the number of spatial sampling points and the signal-to-noise ratio on the separation accuracy are analyzed numerically.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 3 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Sound and Vibration, Volume 442〈/p〉 〈p〉Author(s): N.G.R. de Melo Filho, L. Van Belle, C. Claeys, E. Deckers, W. Desmet〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To enhance the sound insulation performance of double panel partitions at their mass-air-mass resonance frequency, novel compact and low-mass solutions are sought. This paper investigates the use of the locally resonant vibro-acoustic metamaterial concept as a possible solution. The metamaterial solution is applied to one panel of a double panel partition in order to enhance the sound transmission loss at the mass-air-mass resonance. To design the metamaterial solution and predict its sound transmission loss performance, an extension of the multiple reflection theory is proposed, incorporating the dynamic mass of a metamaterial panel. The latter is obtained from the metamaterial plate dispersion curves, calculated using finite element based unit cell modeling. The designed metamaterial solution is manufactured and its insertion loss is measured. The novel design outperforms the original double panel and an equivalent total mass double panel configuration in the targeted mass-air-mass resonance frequency region. The predictions obtained with the proposed method are in good agreement with the experimentally obtained results. This demonstrates the potential of the metamaterial solution to enhance the acoustic insulation at the mass-air-mass resonance and indicates that the proposed method allows a fast, simple and representative indication of their acoustic insulation performance.〈/p〉〈/div〉 〈/div〉