ALBERT

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

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

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

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

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

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

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

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

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

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

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

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

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

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

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

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

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

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

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

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry Letters, Volume 28, Issues 23–24〈/p〉 〈p〉Author(s): J.S. Dileep Kumar, Francesca Zanderigo, Jaya Prabhakaran, Harry Rubin-Falcone, Ramin V. Parsey, J. John. Mann〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Overexpression of Cyclooxygenase-2 (COX-2) enzyme is associated with the pathogenesis of inflammation, cancers, stroke, arthritis, and neurological disorders. Because of the involvement of COX-2 in these diseases, quantification of COX-2 expression using Positron Emission Tomography (PET) may be a biological marker for early diagnosis, monitoring of disease progression, and an indicator of effective treatment. At present there is no target-specific or validated PET tracer available for in vivo quantification of COX-2. The objective of this study is to evaluate [〈sup〉11〈/sup〉C]TMI, a selective COX-2 inhibitor (Ki ≤ 1 nM) in nonhuman primates using PET imaging. PET imaging in baboons showed that [〈sup〉11〈/sup〉C]TMI penetrates the blood brain barrier (BBB) and accumulates in brain in a somewhat heterogeneous pattern. Metabolite analyses indicated that [〈sup〉11〈/sup〉C]TMI undergoes no significant metabolism of parent tracer in the plasma for baseline scans, however a relative faster metabolism was found for blocking scan. All the tested quantification approaches provide comparable tracer total distribution volume (V〈sub〉T〈/sub〉) estimates in the range of 3.2–7 (mL/cm〈sup〉3〈/sup〉). We observed about 25% lower V〈sub〉T〈/sub〉 values in blocking studies with meloxicam, a nonselective COX-2 inhibitor, compared to baseline [〈sup〉11〈/sup〉C]TMI binding. Our findings indicate that [〈sup〉11〈/sup〉C]TMI may be a suitable PET tracer for the quantification of COX-2 in vivo. Further experiments are needed to confirm the potential of this tracer in COX-2 overexpressing models for brain diseases.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0960894X18308515-ga1.jpg" width="487" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈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〉

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

Beschreibung: 〈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〉

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

Beschreibung: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Non-Crystalline Solids, Volume 502〈/p〉 〈p〉Author(s): 〈/p〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

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

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

Beschreibung: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Catalysis, Volume 368〈/p〉 〈p〉Author(s): Michiel Janssen, Lisa Van Emelen, Carlos Marquez, Trees De Baerdemaeker, Dirk E. De Vos〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Selective functionalization of hydrocarbons remains one of the most challenging reactions in organic chemistry. With respect to terminal C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H hydroxylation, electrophilic activation by late transition metals has been considered a promising route. We report the use of Shilov-chemistry inspired Pt catalysis in acetic acid as suitable solvent for the formation of primary alcohols from long linear alkanes. By reacting 〈em〉n〈/em〉-heptane with K〈sub〉2〈/sub〉PtCl〈sub〉4〈/sub〉 under an oxygen atmosphere, a positional selectivity of 18% was reached for 1-heptanol among the C〈sub〉7〈/sub〉 alcohols at significantly high conversion (37%). Moreover, we provide evidence for the intrinsic activity of Pt(II), along with elucidation of the role of specific additives as coordinating ligands. Both acetic anhydride (AA), initially added as protecting agent, and sulfuric acid proved to be essential to obtain an active alkane hydroxylation system; via ESI-MS [Pt(AA)(OSO〈sub〉3〈/sub〉H)〈sub〉3〈/sub〉(H〈sub〉2〈/sub〉O)]〈sup〉+〈/sup〉 and [Pt(CH〈sub〉3〈/sub〉COOH)(OSO〈sub〉3〈/sub〉H)〈sub〉3〈/sub〉(H〈sub〉2〈/sub〉O)]〈sup〉+〈/sup〉 were identified in the active catalytic system. Furthermore, nonselective overoxidation originates from various side reactions, for which a reaction network is proposed. Finally, the stability of the 〈em〉in situ〈/em〉 formed esters was studied in detail by recording time-dependent profiles for the decomposition of different positional isomers of 〈em〉n〈/em〉-octyl acetate, as well as of its fluorinated analogues. Altogether, these results illustrate the clear potential of the proposed concept in forming primary alcohols directly from cheap and abundant alkanes.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021951718304044-ga1.jpg" width="369" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈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〉

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

Beschreibung: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Catalysis, Volume 368〈/p〉 〈p〉Author(s): Gennady I. Panov, Mikhail V. Parfenov, Eugeny V. Starokon, Alexandr S. Kharitonov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Investigation of reaction mechanisms by identifying the intermediates released into the gas phase is most effective at low conversion of reactants, ideally approaching zero. However, conversions below 0.5–1% are rarely used, due to the difficulty of analysis of low-concentration products. The mechanism of the title reaction is a subject of long-term discussion. We studied the mechanism using an original ultralow conversion (ULC) method. The idea is to perform the analysis of products after their preliminary accumulation in a suitable absorbent at the reactor outlet. This allows decreasing conversion by 2–3 orders of magnitude. The ULC experiments were conducted with a Bi–Mo catalyst at 100–250 °C and with propene conversion down to 0.001%. A new so-called allyl hydroxylation mechanism was revealed. A key step is the hydroxylation of the CH〈sub〉3〈/sub〉 group to form an allyl alcohol intermediate, which is further oxidized to acrolein. The mechanism explains all reaction features and was confirmed by experiments at 350 °C.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021951718303804-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

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

Beschreibung: 〈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〉

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

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉

Beschreibung: 〈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〉