bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal structure of trans-diacetonitritrile(diaqua)(N,N,N',N'-tetramethylethylenediamine) nickel(II)dibromide tetrahydrate, [Ni(tmen)(CH3CN)2(H2O)2]2+·2Br–·4H2O, C10H34Br2N4NiO6
Authors: Ishikawa Yuki , Miyamoto Keiko , Horn Ernst 
Published: April 2013

Abstract C10H34Br2N4NiO6, monoclinic, C2/c (no. 15), a = 19.062(4) Å, b = 8.106(2) Å, c = 15.484(3) Å, β = 112.96(3)°, V = 2203.0(9) Å3, Z = 4, Rgt(F) = 0.0348, wRref(F2) = 0.0405, T = 273.2 K.
Crystal structure of dichlorido-(6-methyl-1H-benzo[d]imidazole-2-thiolo κS)-(triphenylphosphine-κP)palladium(II)-methanol monosolvate (1:1), [PdCl2(C8H8N2S)(C18H15P)]·CH3OH, C27H27Cl2N2OPPdS
Authors: Qiu Qi-Ming , Yu Yue , Liu Min , Jin Qiong-Hua , Zhang Cun-Lin 
Published: April 2013

Abstract C27H27Cl2N2OPPdS, triclinic, P1¯ (no. 2), a = 9.0350(8) Å, b = 9.9180(9) Å, c = 15.823(1) Å, α = 89.477(2)°, β = 80.435(1)°, γ = 78.123(1)°, V = 1367.8 Å3, Z = 2, Rgt(F) = 0.0686, wRref(F2) = 0.1901, T = 298 K.
Crystal structure of 1-(propan-2-ylidene)-2-(thiazolo[5,4-b]pyridin-2-yl)- hydrazine, C9H10N4S
Authors: Ma Ning , Guo Wen-Bo , Miao Shao-Bin 
Published: April 2013

Abstract C9H10N4S, monoclinic, P21/c (no. 14), a = 13.076(3) Å, b = 6.654(2) Å, c = 11.230(3) Å, β = 92.740(3)°, V = 976.0 Å3, Z = 4, Rgt(F) = 0.0330, wRref(F2) = 0.0876, T = 296 K.
Bright infrared LEDs based on colloidal quantum-dots
Authors: Sun Liangfeng , Choi Joshua J. , Stachnik David , Bartnik Adam C. , Hyun Byung-Ryool , Malliaras George G. , Hanrath Tobias , Wise Frank W. 
Published: April 2013

ABSTRACTRecord-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm.
New Atomic Force Microscopy Based Astrocyte Cell Shape Index
Authors: Tiryaki Volkan Mujdat , Adia-Nimuwa Usienemfon , Hartz Steven Allen , Xie Kan , Ayres Virginia M. , Ahmed Ijaz , Shreiber David I. 
Published: April 2013

ABSTRACTA new three-dimensional cell shape index using the AFM height images of cells cultured on cell substrates was defined. The new cell shape index revealed quantitative cell spreading information of cells that is not included in the conventional cell shape index. The quantitative morphometry of rat cerebral cortical astrocytes cultured on four different kinds of cell substrates were investigated using the conventional and the new cell shape index, and the results were compared. The new cell shape index showed the quantitative astrocyte spreading and stellation behavior that agrees with the AFM height images of astrocytes.
The role of the micro-porous layer (MPL) in fuel cells: neutron imaging and advanced electrochemical analysis study.
Authors: Boillat Pierre , Oberholzer Pierre , Lehmann Eberhard H. , Scherer Günther G. , Wokaun Alexander 
Published: April 2013

ABSTRACTThe effect of the micro-porous layer (MPL) in polymer electrolyte fuel cells (PEFCs) was studied by a combination of in situ visualization of the liquid water distribution and advanced electrochemical analysis using helox and O2 pulses. Four cells with and without MPLs on the anode and cathode side were tested. Visualization studies showed that the significant changes in performance observed when using an MPL on the cathode side cannot be related to a reduction of the water content in the cathode side diffusion layer (GDL). The helox/O2 pulse analysis indicated that two different mechanisms are responsible for the performance loss without an MPL.
GISAXS study on the annealing behavior of sputtered HfO2 thin films
Authors: Belo G. S. , Nakagomi F. , de Souza P. E. N. , da Silva S. W. , Buchanan D. A. 
Published: April 2013

AbstractGrazing Incidence Small-Angle X-ray Scattering (GISAXS) is a versatile technique for the analysis of nano and micro thin films surfaces. The scattering data depend strongly on the form and distribution of the scattering objects. In the present work GISAXS is used to study hafnium dioxide (HfO2) thin films deposited by magnetron sputtering using different deposition processes and post-deposition annealing conditions. Two distinct types of 15 nm thick samples were produced using different sputtering targets and different gas mixtures. The GISAXS results show that the ellipsoids that compose the thin films present a reduction in their size for both samples sets. For the sputtered Hf metal target samples, the ellipsoid diameter value shifted from 9 nm (as-deposited) to 6 nm following a 800 °C thermal treatment. For the sputtered HfO2 target samples the diameter value shifts from 19 nm (as-deposited) to 3 nm after a 800 °C anneal in oxygen. The size distribution, for both sets of samples, follows a Gaussian distribution function.
Influence of oxygen impurity on containerless solidification of quasicrystalline-forming Zr80Pt20 alloy
Authors: Harada Takeshi , Mizuno Akitoshi , Watanabe Masahito 
Published: April 2013

ABSTRACTThe influence of oxygen content on containerless solidification of Zr80Pt20 alloy has been studied by using conical nozzle levitation (CNL) technique. The doping level of oxygen from 41 to 5450 ppm mass oxygen (PMO) affects the undercooling of the liquid Zr80Pt20 alloy. Time-resolved synchrotron x-ray diffraction revealed that the quasicrystalline (QC) phase precipitated as a primary phase during solidification of the Zr80Pt20 alloy. The amount of the QC phase depends on the oxygen content in the alloy. This indicates that the doping level of oxygen in Zr80Pt20 alloy can be related to the metastable phase formation as well as the glass-formation ability.
Enhancement of Corrosion Resistance AISI 304 Steel by Plasma Polymerized Thin Films
Authors: Santos Nazir M. , Amorim Jayr , Nascente Pedro A.P. , Freire Célia M.A. , Cruz Nilson C. , Rangel Elidiane C. 
Published: April 2013

ABSTRACTThe purpose of this work is the deposition of films in order to increase the corrosion resistance of AISI 304 steel, which is a material used to construct the reactors for bioethanol production. This deposition inhibits the permeation of corrosive species to the film-metal interface. Thin films were prepared by radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD) method using plasmas of hexamethyldisiloxane/argon/oxygen mixtures excited by signals of different powers. The plasma was generated by the application of RF power of 13.56 MHz to the sample holder while keeping grounded the topmost electrode and the chamber walls. The effect of the RF power on the properties of the samples was investigated by perfilometry, X-ray photoelectron spectroscopy (XPS), contact angle, and electrochemical impedance spectroscopy (EIS). The results of the corrosion resistance tests of the AISI 304 steel were interpreted in terms of the energy delivered to the growing layer by plasma excitation power.
Nanostructure and Strain Field in Vertically Aligned Nano-Islands for Si/Ge 2D Photonic Nanocrystals.
Authors: Kiguchi Takanori , Hoshi Yusuke , Tayagaki Takeshi , Usami Noritaka 
Published: April 2013

AbstractThe local strain field and the intermixing of a Ge nano-islands (NIs)/Si spacer stacked structure in a novel solar cell with a p-i-n type Si single crystal with two-dimensional photonic nanocrystals connecting to the vertically aligned NIs were analyzed using electron microscopy. High-angle annular dark field-scanning transmission electron microscope (HAADF-STEM) images show intermixing between Ge and Si clearly and reveal that the surface segregation of Ge becomes advanced. The average composition of the NIs is Ge0.42Si0.58, which is almost constant in a row of vertically aligned NIs. The local strain analysis results obtained from the high-resolution transmission electron microscope (HRTEM) images show that the strain state is partially relaxed after the elastic relaxation of NIs.
An attempt to handle the nanopatterning of materials created under ion beam mixing
Authors: Simeone D. , Baldinozzi G. , Gosset D. , Demange G. , Zhang Y. , Luneville L. 
Published: April 2013

ABSTRACTIn the past fifty years, experimental works based on TEM or grazing incidence X ray diffraction have clearly shown that alloys and ceramics exhibit a nano pattering under irradiation [1,2,3]. Many works were devoted to study the nano patterning induced by ion beam mixing in solids [17,18,19]. Understanding the nano patterning will provide scientific bases to tailor materials with well-defined microstructures at the nanometric scale. The slowing down of impinging particles in solids leads to a complex distribution of subcascades. Each subcascade will give rise to an athermal diffusion of atoms in the medium. In this work, we focused on this point. Based on the well-known Cahn Hilliard Cook (CHC) equation, we analytically calculate the structure factor describing the nano patterning within the mean field approximation. It has shown that this analytical structure factor mimics the structure factor extracted from direct numerical simulations of the time dependent CHC equation. It appears that this structure factor exhibits a universal feature under irradiation.
Bandgap Engineering of Double Perovskites for One- and Two-photon Water Splitting
Authors: Castelli Ivano E. , Thygesen Kristian S. , Jacobsen Karsten W. 
Published: April 2013

ABSTRACTComputational screening is becoming increasingly useful in the search for new materials. We are interested in the design of new semiconductors to be used for light harvesting in a photoelectrochemical cell. In the present paper, we study the double perovskite structures obtained by combining 46 stable cubic perovskites which was found to have a finite bandgap in a previous screening-study.1 The four-metal double perovskite space is too large to be investigated completely. For this reason we propose a method for combining different metals to obtain a desired bandgap. We derive some bandgap design rules on how to combine two cubic perovskites to generate a new combination with a larger or smaller bandgap compared with the constituent structures. Those rules are based on the type of orbitals involved in the conduction bands and on the size of the two cubic bandgaps. We also see that a change in the volume has an effect on the size of the bandgap. In addition, we suggest some new candidate materials that can be used as photocatalysts in one- and two-photon water splitting devices.
The Microscopic Effect of Filler on Rubber Reinforcement: A Coarse-grained Molecular Dynamics Study
Authors: Kimura Yosuke , Sato Masatoshi 
Published: April 2013

ABSTRACTIn this paper, we developed a microscopic approach to understand rubber reinforcement using coarse-grained molecular dynamics simulations. We investigated static uniaxial tensile behavior of filled and unfilled rubber models, and found two reinforcement mechanisms. One of these is the same as the mechanism predicted by Guth, which depends only on the volume content of fillers. We have confirmed this mechanism at small strain region. The other is caused by filler-filler network created by the advantage of chemical bond at large strain. In this region, some polymers linked fillers and were stretched, that is, these polymers generated tension. Additionally, we investigated the effect of filler distribution on rubber reinforcement.
Dynamics and Kinetics of Dislocations in Metals and Alloys Under Dynamic Loading
Authors: Ilnitski Denis , Krasnikov Vasily , Kuksin Alexey , Mayer Alexander , Yanilkin Alexey 
Published: April 2013

ABSTRACTThe work presented is devoted to study the mechanisms and kinetics of plastic deformation of bcc and fcc metals and alloys under shock-wave loading (strain rates > 105 s-1). To study the behavior of metals under conditions described the two scale approach is developed. It comprises molecular dynamics (MD) calculations of dislocation mobility and dislocations nucleation rate and continuum mechanics model with equations for description of elastoplastic deformation, kinetics and dynamics of dislocations.Dislocation velocities as functions of applied shear stress are calculated from MD in a wide temperature range up to the melting point. Velocity-dependent drag coefficient is introduced to approximate the data obtained.The influence of Guinier–Preston (GP) zones on dislocation motion is analyzed. The results obtained are used to evaluate temperature dependence of dynamic flow stress and the evolution of dislocations subsystem under shock loading. Data on the attenuation of the elastic precursor and rare surface velocity profiles calculated for Al are in good agreement with the experiments. Simulation of the free surface velocity profiles during shock-wave loading of AlCu alloys is carried out.
Exploring amyloid aggregates with coarse-grained protein simulations
Authors: Derreumaux Philippe 
Published: April 2013

ABSTRACTProteins are complex, yet elegant, machines fine-tuned by evolution to properly fulfill a variety of tasks in the crowded cellular environment. These are, however, very challenging numerically due to their dimension, number of degrees of freedom and the wide range of relevant time scales. With aging, some proteins misfold and form harmful amyloid aggregates associated with multiple neurodegenerative diseases, and in particular Alzheimer’s, which challenge our society today. Here, I present the coarse-grained OPEP (Optimized Potential for Efficient peptide structure Prediction) force field and what we can learn from OPEP simulations to get insights into the self-assembly of amyloid peptides.
Microstructure simulations within the Lattice Statics formalism: elasticity and morphologies at the atomic scale
Authors: Varvenne C. , Le Bouar Y. , Finel A. , Fèvre M. 
Published: April 2013

ABSTRACTIn this paper, the Lattice Statics formalism is used to perform Monte Carlo simulations of alloy microstructures when elastic effects are present. It provides sets of long-range effective pair interactions (EPIs), defined in a rigid average reference state, that allow us to compute microstructural evolutions on diffusion time scale. A wide composition range is investigated in order to characterize the different precipitation processes with elasticity (nucleation and growth, spinodal decomposition). An advantage of the approach is to include the concentration dependence of both the effective chemical interactions and the elastic properties of the reference state. The importance of this point is illustrated by comparing the precipitation sequences in two alloys with symmetric average concentrations.
Atomistic Modeling of Shock Loading in SiC Ceramics
Authors: Branicio Paulo S. , Zhang Jingyun 
Published: April 2013

ABSTRACTLarge scale molecular-dynamics simulations of plane shock loading in SiC are performed to reveal the interplay between shock-induced compaction, structural phase transformation (SPT) and plastic deformation. The shock profile is calculated for a wide range of particle velocity from 0.1 km/s to 6.0 km/s. Single crystalline models indicate no induced plasticity or SPT for shock loading below 2.0 km/s. For intermediate particle velocity, between 2.0 km/s and 4.5 km/s the generated shock wave splits into an elastic precursor and a zinc blende to rocksalt structural transformation wave. That is induced by the increase in shock pressure to over 90 GPa and results in a steep increase of density from 3.21 g/cm3 to ∼4.65 g/cm3. For particle velocity greater than 4.5 km/s a single overdriven transformation shock wave is generated. These simulation results provide an atomistic view of the dynamic effects of shock impact on single crystal high-strength ceramics.
Selection guidelines for ionic dielectrics with gigantic dielectric response (GDR) based on polaronic phase transition criteria
Authors: Ligatchev Valeri , Yu Zhigen , Zheng Jianwei , Sullivan Michael B. 
Published: April 2013

ABSTRACTDielectric materials with GDR (e.g. CaCu3Ti4O12 – CCTO and isostructural systems, co-doped NiO etc) attract major research interest due to their bright prospective in energy storage and memory devices. However, after years of intensive experimental and theoretical studies of GDR materials, physical nature of their extremely high complex dielectric permittivity (specifically, real part ∼ 104 - 106) is still not established convincingly. Another serious problem is excessively high imaginary part of the permittivity (which usually exceeds real one). Better understanding on physical mechanisms and limitations of GDR behavior in aforementioned dielectrics could be achieved based on polaronic phase transition criteria, proposed S. Fratini and P. Quémerais [Eur. Phys. Journ. B14, 99 (2000)]. In particular, ‘melting’ of Polaronic Wigner Crystal (PWC) either to ‘polaronic liquid’ or ‘electron liquid’ manifests two different scenarios of PWC phase transition at increment of concentrations of appropriate dopants. The former scenario is certainly preferable for ionic dielectrics with GDR behavior, while the latter one would yield in metal-like dielectric response with very high real permittivity, but unacceptable loss. Described approach provides physically transparent guidelines for selection of prospective host dielectrics with GDR behavior and quantitative estimations on critical dopant/polaron concentrations, corresponding to both aforementioned types of the phase transitions as well as temperature ranges suitable for GDR.
Surface Dynamics and Hydrophobicity of High-Voltage Insulator Polymers
Authors: Fritz Oliver , Shemella Philip T. , Laino Teodoro , Curioni Alessandro 
Published: April 2013

ABSTRACTUsing large-scale, all-atom molecular dynamics simulations, we show that microscopic mechanisms found for molecules on the material surface of siloxane polymers can explain an important surface-hydrophobicity restoration process. In particular, a net orientation and polarization on the surface can be found which is the result of an augmented motion of certain molecules. Based on this result, surface hydrophobicity, its loss through oxidation, and its restoration through a unique interaction between cyclomethicone molecules, oxidized methyl groups, and counterions can be understood.
Nickel Foam as a Substrate for III-nitride Nanowire Growth
Authors: Mastro Michael A. , Nepal Neeraj , Kub Fritz , Hite Jennifer K. , Kim Jihyun , Eddy Charles R. 
Published: April 2013

ABSTRACTThis article presents the use of flexible metal foam substrates for the growth of III-nitride nanowire light emitters to tackle the inherent limitations of thin-film light emitting diodes as well as fabrication and application issues of traditional substrates. A dense packing of gallium nitride nanowires were grown on a nickel foam substrate. The nanowires grew predominantly along the a-plane direction, normal to the local surface of the nickel foam. Strong luminescence was observed from undoped GaN and InGaN quantum well light emitting diode nanowires.
Melting Gel Films for Low Temperature Seals
Authors: Jitianu Mihaela , Jitianu Andrei , Stamper Michael , Aboagye Doreen , Klein Lisa C. 
Published: April 2013

ABSTRACTMelting gels are silica-based hybrid gels with the curious behavior that they are rigid at room temperature, but soften around 110°C. A typical melting gel is prepared by mixing methyltriethoxysilane (MTES) and dimethyldiethoxysilane (DMDES). MTES has one methyl group substituted for an ethoxy, and DMDES has two substitutions. The methyl groups do not hydrolyze, which limits the network-forming capability of the precursors. To gain insight into the molecular structure of the melting gels, differential scanning calorimetry and oscillatory rheometry studies were performed on melting gels before consolidation. According to oscillatory rheometry, at room temperature, the gels behave as viscous fluids, with a viscous modulus, G″(t,ω0) that is larger than the elastic modulus, G′(t,ω0). As the temperature is decreased, gels continue to behave as viscous fluids, with both moduli increasing with decreasing temperature. At some point, the moduli cross over, and this temperature is recorded as the glass transition temperature Tg. The Tg values obtained from both methods are in excellent agreement. The Tg decreases from -0.3oC to -56oC with an increase in the amount of di-substituted siloxane (DMDES) from 30 to 50 mole %. A decrease of the Tg follows an increase of the number of hydrolytically stable groups, meaning a decrease in the number of oxygen bridges between siloxane chains.
Growth and physical properties of vanadium oxide thin films with controllable phases
Authors: Ji Yanda , Zhang Yin , Gao Min , Yuan Zhen , Jin Changqing , Lin Yuan 
Published: April 2013

ABSTRACTVanadium oxides thin films with variable oxidation states have attracted great attention due to their unique electrical, optical properties and many important applications in microelectronics, infrared optical devices, and energy harvest systems. However, to fabricate vanadium oxide thin films with controllable phases and desired transport properties is still a challenge by using a chemical solution deposition (CSD) technique. In this paper, we report that vanadium oxide thin films with well controlled phases such as rhombohedral V2O3 and monoclinic VO2 could be synthesized on Al2O3 (0001) substrates using a CSD technique ---- polymer assisted deposition (PAD). Both V2O3 and VO2 thin films can be well controlled with good epitaxial quality by optimizing the fabrication parameters. The electrical resistivity changes 3∼4 orders of magnitude at metal insulator transition for both epitaxial V2O3 and VO2 thin films. The correlation between the physical properties and the microstructures of the films will be discussed.
Is There a Positive Effect of Smoking Cessation on Periodontal Health? A Systematic Review
Authors: Fiorini Tiago , Musskopf Marta Liliana , Oppermann Rui Vicente , Susin Cristiano 
Published: April 2013

Background: Although the detrimental effects of tobacco on the periodontal tissues have been reported extensively, little is known about the potential beneficial effect of smoking cessation on periodontal health. The aim of this systematic review is to evaluate the effect of smoking cessation on periodontitis progression and response to periodontal therapy.Methods: Two independent reviewers completed the review process through title (n = 118), abstract (n = 24), and whole‐paper selection (n = 5). Sources include Medline and EMBASE databases (up to December 2012) and a reference list of selected studies. Prospective studies comparing progression rates of periodontitis between smokers and quitters and clinical trials evaluating the effect of smoking‐cessation programs, alone or in combination with periodontal treatment, were included. At least 1 year of follow‐up was required for inclusion.Results: Of 331 potentially relevant publications, five studies fulfilled the inclusion criteria. Because of heterogeneity of the studies, a meta‐analysis could not be performed. One study reported that the progression of clinical attachment loss (AL) ≥3 mm during a 6‐year period was approximately three times higher among smokers than quitters (P <0.001). Two studies (10 and 20 years of follow‐up) observed a decrease in radiographic bone loss of ≈30% among quitters when compared with smokers. Among individuals receiving non‐surgical periodontal treatment, quitters were more likely to have periodontal probing depth reductions (P <0.05) than non‐quitters/oscillators. No differences in AL were observed.Conclusion: Based on the limited available evidence, smoking cessation seems to have a positive influence on periodontitis occurrence and periodontal healing.