bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature-dependent evolution of RbBSi2O6 glass into crystallineRb-boroleucite according to X-ray diffraction data
Authors: Levin Aleksandr A. , Filatov Stanislav K. , Paufler Peter , Bubnova Rimma S. , Krzhizhanovskaya Maria G. , Meyer Dirk C. 
Published: June 2013

Abstract
The temperature-dependent evolution of the glass into a crystalline phase is studied for a rubidium borosilicate glass of composition 16.7 Rb2O · 16.7 B2O3 · 66.6 SiO2 employing X-ray diffraction (XRD) data. A glass sample was prepared by melt quenching from 1500°С within 0.5 hour. The glass sample was step-wise annealed at 13 distinct temperatures from 300 °C up to 900 °C for 1 h at every annealing step. To investigate changes in the glass structure, angle-dispersive XRD was applied by using an energy-resolving semiconductor detector. The radial distribution functions (RDFs) were calculated at every stage. For polycrystalline states the crystal structure of the samples with different thermal history was refined using the Rietveld method. Comparing correlation distances estimated from RDFs of glass and polycrystalline samples and mean interatomic distances calculated for polycrystalline samples by using atomic coordinates after Rietveld refinement, it is concluded that the borosilicate glass under study is converted into the crystalline state in the temperature range of 625–750 °C (i.e. in the temperature range close to the glass transition range 620–695 °C as determined by differential scanning calorimetry by using of heating rate of 20 K/min) at an average heating rate of about 0.35 K/min. When the heating rate is increased up to 10 or 20 K/min, the crystallisation temperature shifts sharply up to 831–900 °C and 878–951 °C, respectively. XRD data give evidence that distinctive traces of cubic RbBSi2O6 appear from glass at about 625 °C and a two-phase range exists up to 750 °C. After annealing at higher temperatures (800–900 °C) the crystal structure practically does not change any more.
Immobilization and Characterization of RuCl2(PPh3)3 Mesoporous Silica SBA-3
Authors: Grünberg Anna , Gutmann Torsten , Rothermel Niels , Yeping Xu , Breitzke Hergen , Buntkowsky Gerd 
Published: June 2013

Abstract
The five-fold coordinated ruthenium (II) catalyst RuCl2(PPh3)3 is heterogenized on the surface of amine functionalized mesoporous silica material SBA-3 and studied by BET, XRD and 31P CP-MAS solid-state NMR. The spectra indicate the replacement of one or two of the triphenyl-phosphine groups in the course of the grafting. To distinguish between both possibilities two-dimensional J-resolved 31P MAS solid-state NMR combined with quantum chemical calculations is employed. The changes of the scalar coupling pattern between the neat catalyst and the immobilized catalyst suggest the replacement of two of the PPh3-groups by coordinative bonds to the amine-functions of the linker. DFT calculations reveal the absence of two chemically and magnetically equivalent phosphines and confirm the replacement of two PPh3-groups. This finding is similar to the results observed for the binding of the rhodium in the Wilkinson's catalyst, despite the different coordination of the metals (four-fold versus five-fold), the presence of two chlorine ligands and the different transition metal.
Studying Recombination with High-Throughput Sequencing: An Educational Primer for Use with “Fine-Scale Heterogeneity in Crossover Rate in the garnet-scalloped Region of the Drosophila melanogaster X chromosome”
Authors: Heil Caiti S Smukowski , Noor Mohamed A F 
Published: June 2013

Abstract
An article by Singh and colleagues in this issue of GENETICS quantifies variation in recombination rate across a small region of the Drosophila melanogaster genome, providing an opportunity for instructors of genetics to introduce or reinforce important concepts such as recombination and recombination rate variation, genome sequencing, and sequence features of the genome. Additional background information, a detailed explanation of the methods used in this study, and discussion questions are provided.
Related article in GENETICS: Singh, N. D., E. A. Stone, C. F. Aquadro, and A. G. Clark, 2013 Fine-scale heterogeneity in crossover rate in the garnet-scalloped region of the Drosophila melanogaster X chromosome. Genetics 194: 375–387.
The Modest Beginnings of One Genome Project
Authors: Kaback David B 
Published: June 2013

AbstractOne of the top things on a geneticist’s wish list has to be a set of mutants for every gene in their particular organism. Such a set was produced for the yeast, Saccharomyces cerevisiae near the end of the 20th century by a consortium of yeast geneticists. However, the functional genomic analysis of one chromosome, its smallest, had already begun more than 25 years earlier as a project that was designed to define most or all of that chromosome’s essential genes by temperature-sensitive lethal mutations. When far fewer than expected genes were uncovered, the relatively new field of molecular cloning enabled us and indeed, the entire community of yeast researchers to approach this problem more definitively. These studies ultimately led to cloning, genomic sequencing, and the production and phenotypic analysis of the entire set of knockout mutations for this model organism as well as a better concept of what defines an essential function, a wish fulfilled that enables this model eukaryote to continue at the forefront of research in modern biology.
Progress in Chromogenic Materials and Devices: New Data on Electrochromics and Thermochromics
Authors: Granqvist C. G. , Li S.-Y. , Pehlivan İ. Bayrak , Niklasson G. A. 
Published: June 2013

ABSTRACTElectrochromic (EC) and thermochromic (TC) materials are of much interest for “smart” windows which combine energy efficiency with the provision of indoor comfort. This paper summarizes results from several recent studies related to nanoparticles of transparent and electrically conducting ITO (i.e., In2O3:Sn) and of thermochromic VO2. Specifically, we consider (i) the use of ITO nanoparticles in polaronic EC devices in order to suppress near-infrared solar transmittance, (ii) performance limits for plasmonic EC devices embodying ITO nanoparticles, and (iii) ITO-VO2-based nanocomposites with joint low thermal emittance and TC properties, and with Mg-doping of the VO2 as a means for boosting the luminous transmittance. Both experimental and theoretical results are presented.
The Elements of Magnetics
Authors: Constantinides Steve 
Published: June 2013

ABSTRACTThe 20th century saw rapid and dramatic improvements in permanent magnet materials. It has been 31 years since the discovery of neodymium-iron-boron and numerous companies and laboratories are seeking to produce a new and superior material. Topics discussed herein are material options, economics of selected materials and market drivers in material selection. Market issues include manufacturability by shape, size, and material yield; raw material supply including cost and dependability of the supply chain; raw material and magnet product price stability; development of applications based on commercial needs, government legislation and consumer demand. “Need is the mother of invention” and no discussion would be complete without covering why a new material would be beneficial from an applications point of view especially in energy production and consumption. Therefore, an introduction will be provided for select, major applications using permanent magnets and the growth forecasts for these.
Graphene Research in China
Authors: Chen Kexin 
Published: June 2013

ABSTRACTGraphene, a monolayer of sp2-bonded carbon atoms, has been attracting worldwide interests because of its unique two-dimensional structure, various fascinating properties and a wide range of intriguing potential applications. The graphene research is very active in China and has been developing rapidly in the past few years, which covers nearly all the areas related to graphene including theories, synthesis, physical and chemical properties, and applications. Over 100 research institutions have been involved in graphene research with fast-growing project supports. In this paper, the status of graphene research in China is first discussed based on the number of publications and patents as well as the institutions involved. Then the projects and fundings from both government and companies for graphene research are briefly introduced. Finally, the highlights of graphene research in China are reviewed, which include chemical vapor deposition growth and transfer, mass production, and assembly of graphene, and its applications in energy storage, sensing, composites and solar cells.
Nanostructuration of Cr/Si layers induced by ion beam mixing
Authors: Luneville L. , Largeau L. , Deranlot C. , Moncoffre N. , Serruys Y. , Ott F. , Baldinozzi G. , Simeone D. 
Published: June 2013

ABSTRACTThis work clearly demonstrates that the X Ray Reflectometry technique (XRR), extensively used to assess the quality of microelectronic devices can be a useful tool to study the first stages of ion beam mixing. This technique allows measuring the evolution of the Si concentration profile in irradiated Cr/Si layers. From the analysis of the XRR profiles, it clearly appears that the Si profile cannot be described by a simple error function.
Simulating Radiation-Induced Defect Formation in Pyrochlores
Authors: Gunn David S.D. , Purton John A. , Todorov Ilian T. 
Published: June 2013

ABSTRACTThe accuracy and robustness of new Buckingham potentials for the pyrochlores Gd2Ti2O7 and Gd2Zr2O7 is demonstrated by calculating and comparing values for a selection of point defects with those calculated using a selection of other published potentials and our own ab inito values. Frenkel pair defect formation energies are substantially lowered in the presence of a small amount of local cation disorder. The activation energy for oxygen vacancy migration between adjacent O48f sites is calculated for Ti and Zr pyrochlores with the energy found to be lower for the non-defective Ti than for the Zr pyrochlore by ∼0.1 eV. The effect of local cation disorder on the VO48f → VO48f migration energy is minimal for Gd2Ti2O7, while the migration energy is lowered typically by ∼43 % for Gd2Zr2O7. As the healing mechanisms of these pyrochlores are likely to rely upon the availability of oxygen vacancies, the healing of a defective Zr pyrochlore is predicted to be faster than for the equivalent Ti pyrochlore.
Helium Bubbles in Fe: Equilibrium Configurations and Modification by Radiation
Authors: Gai Xiao , Smith Roger , Kenny Steven 
Published: June 2013

ABSTRACTWe have examined the properties of helium bubbles in Fe using two different Fe-He potentials. The atomic configurations and formation energies of different He-vacancy complexes are determined and their stability in the region of nearby collision cascades is investigated. The results show that the optimal He to Fe vacancy ratio increases from about 1:1 for approximately 5 vacancies up to about 4:1 for 36 vacancies. Collision cascades initiated near the complex show that Fe vacancies produced by the cascades readily become part of the He-vacancy complexes. The energy barrier for an isolated He interstitial to diffuse was found to be 0.06 eV. Thus a possible mechanism for He bubble growth would be the addition of vacancies during a radiation event followed by the subsequent accumulation of mobile He interstitials produced by the corresponding nuclear reaction.
Removal of Lead Ions in an Aqueous Medium with Activated Carbon Fibers
Authors: Ramírez-Rodríguez Teresa , Castillo-Alvarado Fray de Landa 
Published: June 2013

ABSTRACTPoly(acrylonitrile) fibers are used in the manufacture of activated carbon fibers, which are activated with phosphate groups for the removal of lead ions in aqueous solutions. Removal of lead ions is performed in a water bath at 30°C. Trough isotherm models of Langmuir and Freundlich analyzed the aqueous solution. Kinetic analysis is performed using the model pseudo-first and pseudo-second order. The result show that adsorption equilibrium is adjusted to the Freundlich model and the kinetic model of pseudo-second order led to the best fit correlation.
Finite Element Simulation of Steel Quench Distortion- Parametric Analysis of Processing Variables
Authors: García-Pastor F. A. , López-García R.D. , Alfaro-López E. , Castro-Román M. J. 
Published: June 2013

ABSTRACTSteel quenching from the austenite region is a widely used industrial process to increase strength and hardness through the martensitic transformation. It is well known, however, that it is very likely that macroscopic distortion occurs during the quenching process. This distortion is caused by the rapidly varying internal stress fields, which may change sign between tension and compression several times during quenching. If the maximum internal stress is greater than the yield stress at given processing temperature, plastic deformation will occur and, depending on its magnitude, macroscopic distortion may become apparent.The complex interaction between thermal contraction and the expansion resulting from the martensitic transformation is behind the sign changes in the internal stress fields. Variations in the steel composition and cooling rate will result in a number of different paths, which the internal stresses will follow during processing. Depending on the route followed, the martensitic transformation may hinder the thermal stresses evolution to the point where the stress fields throughout the component may actually be reverted. A different path may support the thermal stresses evolution further increasing their magnitude. The cross-sectional area also affects the internal stresses magnitude, since smaller areas will have further trouble to accommodate stress, thus increasing the distortion. Additionally, the bainitic transformation occurring during relatively slow cooling rates may have an important effect in the final stress field state.A finite-element (FE) model of steel quenching has been developed in the DEFORM 3D simulation environment. This model has taken into account the kinetics of both austenite-bainite and austenite-martensite transformations in a simplified leaf spring geometry. The results are discussed in terms of the optimal processing parameters obtained by the simulation against the limitations in current industrial practice.
Phase Formation at Selective Laser Synthesis in Al2O3–TiO2-Y2O3 Powder Compositions
Authors: Vlasova M. , Kakazey M. , Márquez-Aguilar P. A. , Ragulya A. , Stetsenko V. , Bykov A. 
Published: June 2013

ABSTRACTThe phase formation in the zone of directional laser irradiation of compacted Al2O3–TiO2–Y2O3 mixtures has been investigated. It is established that phase formation is carried out within the framework of binary mixtures Al2O3 – Y2O3 and Y2O3 – TiO2.
Investigation of a Nanoporous Gold / TiO2 Catalyst by Electron Microscopy and Tomography
Authors: Frank Kristian , Wichmann Andre , Wittstock Arne , Bäumer Marcus , Mädler Lutz , Rosenauer Andreas 
Published: June 2013

ABSTRACTNanoporous gold is a material with many possible applications e.g. in catalysts, sensors and electrode materials. We studied the functionalization of the nanoporous gold with TiO2 particles. Aiming at the low temperature oxidation of CO, the nanoporous gold can be coated with TiO2 in order to enhance catalytic activity. Structure and distribution of the TiO2 on the gold surface are important structural features, which were investigated by transmission electron microscopy. The preparation of the porous gold was tested with focused ion beam - preparation, conventional Ar+ ion beam preparation of nanoporous gold embedded in epoxy and ultramicrotome preparation of nanoporous gold embedded in epoxy. Considering the beam damage on the structure and the contamination of the surface, ultramicrotome preparation turned out to be the best solution. It was shown, that the gold ligaments are abundantly covered by approximately 5 nm TiO2 particles. The determination of the largest lattice fringe distance in high resolution mode revealed that the crystalline nanoparticles consist of the anatase phase. The spatial Ti distribution was measured with energy filtered transmission electron microscopy. Scanning transmission electron microscopy tomography was applied to reconstruct the three-dimensional structure of the gold coated with TiO2 particles.
Broad-band, High-efficiency Optical Absorbers Derived From Carbon Nanomaterials
Authors: Kaul Anupama B. , Coles James , Eastwood Michael , Green Robert , Bandaru Prabhakar 
Published: June 2013

ABSTRACTOptical absorption efficiency, an important metric for sensing, radiometric and energy harvesting applications, has been studied theoretically and experimentally in porous, ordered nanostructures, including multi-walled- (MW) carbon nanotubes (CNTs) and single-walled- (SW) CNTs. We have characterized the absorption efficiencies in the 350 nm -7000 nm wavelength range of vertically aligned MWCNT arrays with high site densities synthesized directly on metallic substrates using a plasma-enhanced (PE)- chemical vapor deposition (CVD) process. Our ultra-thin absorbers exhibit a reflectance as low as ∼ 0.02 % (100 X lower than the benchmark). Such high efficiency absorbers are particularly attractive for radiometry, as well as energy harnessing applications. This work increases the portfolio of materials that can be integrated with such absorbers due to the potential for reduced synthesis temperatures arising from a plasma process. Optical modeling calculations were conducted that enabled a determination of the extinction coefficient in the films.
Novel Method and Device for High Resolution and Quantitative Sizing of Nanoparticles Suspended in Liquids
Authors: Zerrath Axel F. , Farnsworth James E. , Scheckman Jacob H. , Higgins Jonathan S. , Willis Erik 
Published: June 2013

ABSTRACTA new technology to size nanoparticles in liquids is presented. The technique is based on aerosol technology coupled to a nanoparticle nebulizer. This allows number concentration measurements in the size range ca. 5 to 500 nm with high peak resolution.
Transportation of Hydrogen Molecules Enabled by Tortional Buckling Instability of Carbon Nanoscrolls
Authors: Huang Yinjun , Li Teng 
Published: June 2013

ABSTRACTUsing molecular dynamics simulations, we demonstrate a transportation mechanism of hydrogen molecules enabled by the torsional buckling instability of carbon nanoscrolls. The transportation mechanism is shown to be of high efficacy and robust over a range of loading rates. The findings shed light on potential application of carbon nanoscroll based hydrogen storage.
Thermo-physical behaviors of carbon nanofiber reinforced polylactic acid
Authors: Adhikari Ananta Raj , Sarkar Kamal , Lozano Karen 
Published: June 2013

ABSTRACT:Studies have demonstrated that the reinforcement of polymeric matrices using nanofiller can results with better thermo-physical properties of polymer. Carbon nanofiber (CNF) is a unique quasi-one dimensional nanostructure with large numbers of edges and defects compared to carbon nanotube (CNT). Further the availability in large quantity along with lower cost makes them an important nanomaterial for future technology. We have previously used CNF in different thermoplastic polymers. In this study CNFs were used with water soluble thermoplastic aliphatic polyster polylactic acid (PLA) and studied their thermal and mechanical properties. Thermal analysis using Thermogravimetric Analysis showed enhanced thermal stability of the polymer at higher nanotube loading (>1 wt%) and decrease of thermal stability at higher loading (>10 wt%). Crystallization thermogram of PLA was modified heavily with the addition of nanofibers changing clearly from one stage to two stage crystallization. In addition, CNF facilitates the crystallization of PLA resulting in an increase of its crystallization. The mechanical testing showed the steady increase of modulus of the composites with the nanofiber content within the range of study which can be regarded as due to the change in interface property of the composites.
Supergene and Hypogene Halloysite in a Porphyry-Epithermal Environment at Cerro la Mina, Chiapas, Mexico
Authors: Kyne Roisin , Hollings Pete , Jansen Nicholas H. , Cooke David R. 
Published: June 2013

Abstract
Halloysite, a phyllosilicate clay mineral chemically similar to but structurally different from kaolinite, occurs in a variety of mineral deposit types. It is, however, difficult to identify and dehydrates quite readily. When identified in a porphyry or epithermal environment, halloysite is often interpreted to be a low-temperature polymorph of kaolinite and an indication of supergene processes. The occurrence of halloysite in the Cerro la Mina Au (Cu-Mo) prospect, Chiapas, Mexico, was investigated to determine if halloysite in porphyry-epithermal deposits might also be the product of hypogene processes. The prospect consists of Quaternary volcaniclastic breccias intruded by monzodiorites and trachyandesites crosscut by a volcanic-hydrothermal breccia pipe. Gold-copper-molybdenum mineralization at Cerro la Mina is structurally and lithologically controlled by matrix-rich breccia pipes hosting all of the significant alteration and mineralization drilled to date. Average grades within the prospect are 0.4 ppm Au, 0.16% Cu, and 131 ppm Mo. A total of 100 samples were obtained from 22 diamond drill holes over a range of stratigraphic levels. X-ray diffraction (XRD) and SWIR techniques were employed to identify the different clay minerals found within these samples, including halloysite, kaolinite, dickite, and illite. Identification of halloysite and kaolinite were facilitated by the use of formamide intercalation to produce distinctive peaks for the two minerals in X-ray diffractograms. Halloysite and kaolinite were found to occur from the current erosional surface to depths of over 800 m. Halloysite occurs as both the hydrated 10Å and dehydrated 7Å forms within the deposit. The morphology of the halloysite present is that of well-developed tubes and spheroids. Results of the study show that halloysite associated with gypsum and jarosite is of supergene origin, whereas halloysite occurring with quartz, alunite, dickite, kaolinite, and pyrite is of hypogene origin.
GRAVITATIONAL FRACTIONATION OF ISOTOPES AND DISSOLVED COMPONENTS AS A FIRST-ORDER PROCESS IN CRUSTAL FLUIDS
Authors: Bons Paul D. , Gomez-Rivas Enrique 
Published: June 2013

AbstractThe origin of ore-forming hydrothermal fluids and mechanisms of ore formation are commonly inferred from chemical and isotopic signatures. Fluid mixing and fluid-rock interaction are well-known processes that modify and produce these signatures, respectively. We propose that gravitational fractionation is an additional, hitherto not considered process that can significantly affect fluid signatures. Gravitational fractionation is the tendency for heavier components in a fluid to concentrate at the base of a reservoir. In stagnant fluids, gravitational fractionation can lead to significant changes in isotopic signatures, but also halogen ratios, within tens of millions of years. Rising fractionated fluids can give the same signatures that are classically and potentially erroneously interpreted as indicating mixing of surface-derived and deeper fluids. Recognition of gravitational fractionation as an additional first-order process affecting fluid composition necessitates a thorough reevaluation of models for crustal fluid flow, especially for the formation of unconformity-related hydrothermal ore deposits.