bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting Thermal Properties of Crystals Using Machine Learning
Authors: Tawfik Sherif Abdulkader , Isayev Olexandr , Spencer Michelle J. S. , Winkler David A. 
Published: December 2019

AbstractCalculating vibrational properties of crystals using quantum mechanical (QM) methods is a challenging problem in computational material science. This problem is solved using complementary machine learning methods that rapidly and reliably recapitulate entropy, specific heat, effective polycrystalline dielectric function, and a non‐vibrational property (band gap) for materials calculated by accurate but lengthy QM methods. The materials are described mathematically using property‐labeled materials fragment descriptors. The machine learning models predict the QM properties with root mean square errors of 0.31 meV per atom per K for entropy, 0.18 meV per atom per K for specific heat, 4.41 for the trace of the dielectric tensor, and 0.5 eV for band gap. These models are sufficiently accurate to allow rapid screening of large numbers of crystal structures to accelerate material discovery.
Mechanochemical Synthesis: A Tool to Tune Cation Site Disorder and Ionic Transport Properties of Li3MCl6 (M = Y, Er) Superionic Conductors
Authors: Schlem Roman , Muy Sokseiha , Prinz Nils , Banik Ananya , Shao‐Horn Yang , Zobel Mirijam , Zeier Wolfgang G. 
Published: December 2019

AbstractThe lithium‐conducting, rare‐earth halides, Li3MX6 (M = Y, Er; X = Cl, Br), have garnered significantly rising interest recently, as they have been reported to have oxidative stability and high ionic conductivities. However, while a multitude of materials exhibit a superionic conductivity close to 1 mS cm−1, the exact design strategies to further improve the ionic transport properties have not been established yet. Here, the influence of the employed synthesis method of mechanochemical milling, compared to subsequent crystallization routines as well as classic solid‐state syntheses on the structure and resulting transport behavior of Li3ErCl6 and Li3YCl6 are explored. Using a combination of X‐ray diffraction, pair distribution function analysis, density functional theory, and impedance spectroscopy, insights into the average and local structural features that influence the underlying transport are provided. The existence of a cation defect within the structure in which Er/Y are disordered to a new position strongly benefits the transport properties. A synthetically tuned, increasing degree of this disordering leads to a decreasing activation energy and increasing ionic conductivity. This work sheds light on the possible synthesis strategies and helps to systematically understand and further improve the properties of this class of materials.
Sample collection for laboratory‐based study of the nasal airway and sinuses: a research compendium
Authors: Massey Conner J. , Diaz Del Valle Fernando , Abuzeid Waleed M. , Levy Joshua M. , Mueller Sarina , Levine Corrina G. , Smith Stephanie S. , Bleier Benjamin S. , Ramakrishnan Vijay R. 
Published: December 2019

BackgroundCollection of biologic samples from the nasal cavity and paranasal sinuses is of critical importance to the study of infectious or inflammatory conditions that affect both upper and lower airways. Numerous techniques for the study of ex‐vivo samples exist, with specific applications, strengths, and weaknesses associated with each of them. In this compendium we summarize the available methods for collection of primary human samples and incorporate expert discussion of the pros, cons, and applications associated with each technique.MethodsAn expert panel containing members of the American Rhinologic Society's Research and Grants Committee compiled this educational reference. Rationale for use and the potential advantages and disadvantages are discussed. Research protocols and key references are enumerated.ResultsSampling of the nasal cavity and paranasal sinuses can be achieved through a number of methods. Nonspecific sinonasal secretions may be collected via forced exhalation, nasal lavage, and nasal spray aspiration. Targeted collection of sinonasal secretions may be achieved via endoscopic placement of absorbent matrices. Nasal cytology or collection of superficial epithelium may be completed via brushing or scraping of endonasal structures. Collection of mucosal biopsies may be completed via sinonasal explant or full‐thickness biopsy.ConclusionMultiple sampling techniques are available to collect biologic samples from the sinonasal cavity. These techniques differ in their ease of application, reproducibility, sample yield, and utility for different sinonasal pathologies or research goals. An appreciation of the benefits and drawbacks of each approach will allow investigators to select the techniques most appropriate for achieving research objectives.
Chemical Synthesis of Native S‐Palmitoylated Membrane Proteins through Removable‐Backbone‐Modification‐Assisted Ser/Thr Ligation
Authors: Huang Dong‐Liang , Montigny Cédric , Zheng Yong , Beswick Veronica , Li Ying , Cao Xiu‐Xiu , Barbot Thomas , Jaxel Christine , Liang Jun , Xue Min , Tian Chang‐Lin , Jamin Nadège , Zheng Ji‐Shen 
Published: December 2019

AbstractThe preparation of native S‐palmitoylated (S‐palm) membrane proteins is one of the unsolved challenges in chemical protein synthesis. Herein, we report the first chemical synthesis of S‐palm membrane proteins by removable‐backbone‐modification‐assisted Ser/Thr ligation (RBMGABA‐assisted STL). This method involves two critical steps: 1) synthesis of S‐palm peptides by a new γ‐aminobutyric acid based RBM (RBMGABA) strategy, and 2) ligation of the S‐palm RBM‐modified peptides to give the desired S‐palm product by the STL method. The utility of the RBMGABA‐assisted STL method was demonstrated by the synthesis of rabbit S‐palm sarcolipin (SLN) and S‐palm matrix‐2 (M2) ion channel. The synthesis of S‐palm membrane proteins highlights the importance of developing non‐NCL methods for chemical protein synthesis.
A Cofactor‐Substrate‐Based Supramolecular Fluorescent Probe for the Ultrafast Detection of Nitroreductase under Hypoxic Conditions
Authors: Jiao Yang , Zhang Lei , Gao Xu , Si Wen , Duan Chunying 
Published: December 2019

AbstractIdentifying the location and expression levels of enzymes under hypoxic conditions in cancer cells is vital in early‐stage cancer diagnosis and monitoring. By encapsulating a fluorescent substrate,L‐NO2, within the NADH mimic‐containing metal–organic capsule Zn‐MPB, we developed a cofactor‐substrate‐based supramolecular luminescent probe for ultrafast detection of hypoxia‐related enzymes in solution in vitro and in vivo. The host–guest structure fuses the coenzyme and substrate into one supramolecular probe to avoid control by NADH, switching the catalytic process of nitroreductase from a double‐substrate mechanism to a single‐substrate one. This probe promotes enzyme efficiency by altering the substrate catalytic process and enhances the electron transfer efficiency through an intra‐molecular pathway with increased activity. The enzyme content and fluorescence intensity showed a linear relationship and equilibrium was obtained in seconds, showing potential for early tumor diagnosis, biomimetic catalysis, and prodrug activation.
Guanine‐Stabilized Formamidinium Lead Iodide Perovskites
Authors: Hong Li , Milić Jovana V. , Ahlawat Paramvir , Mladenović Marko , Kubicki Dominik J. , Jahanabkhshi Farzaneh , Ren Dan , Gélvez‐Rueda María C. , Ruiz‐Preciado Marco A. , Ummadisingu Amita , Liu Yuhang , Tian Chengbo , Pan Linfeng , Zakeeruddin Shaik M. , Hagfeldt Anders , Grozema Ferdinand C. , Rothlisberger Ursula , Emsley Lyndon , Han Hongwei , Graetzel Michael 
Published: December 2019

AbstractFormamidinium (FA) lead iodide perovskite materials feature promising photovoltaic performances and superior thermal stabilities. However, conversion of the perovskite α‐FAPbI3 phase to the thermodynamically stable yet photovoltaically inactive δ‐FAPbI3 phase compromises the photovoltaic performance. A strategy is presented to address this challenge by using low‐dimensional hybrid perovskite materials comprising guaninium (G) organic spacer layers that act as stabilizers of the three‐dimensional α‐FAPbI3 phase. The underlying mode of interaction at the atomic level is unraveled by means of solid‐state nuclear magnetic resonance spectroscopy, X‐ray crystallography, transmission electron microscopy, molecular dynamics simulations, and DFT calculations. Low‐dimensional‐phase‐containing hybrid FAPbI3 perovskite solar cells are obtained with improved performance and enhanced long‐term stability.
Synergy effects in dielectric and thermal properties of layered ethylene vinyl acetate composites with carbon and Fe3O4 nanoparticles
Authors: Bertasius Povilas , Macutkevic Jan , Banys Juras , Gaidukovs Sergejs , Barkane Anda , Vaivodiss Romans 
Published: December 2019

ABSTRACTProperties of layered composites with carbon nanotube (CNT), GnP, Fe3O4 nanoinclusions, and hybrid composites with these nanoinclusions were investigated in the wide frequency range (from 20 Hz to 2 THz). All investigated composites (except with single Fe3O4 inclusions) are above percolation threshold. The strong enhancement of microwave and terahertz radiation absorption is observed in hybrid composites in comparison with composites with single inclusions. The synergy effect is discussed in terms of the complex impedance and the distribution of relaxation times. At low temperatures (below 200 K), the electrical conductivity of all hybrid composites follows the tunneling law model and the lowest potential barrier was estimated for composites with CNT inclusions. The best thermal properties are observed for composites with CNT inclusions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48814.
Geometric scaling applied to lepton–ion collisions
Authors: Ben Felipe G. , Machado Magno V. T. , Sauter Werner K. 
Published: December 2019

AbstractIn this article, we discuss a scaling function for the cross section in deeply virtual compton scattering (DVCS) and exclusive vector meson production in both γ*p and γ*A processes. Our description relies on the geometric scaling phenomenon in which cross sections are a function of a single variable , where Q2 is the photon virtuality and represents the saturation scale that drives the energy dependence and nuclear effects. We make a prediction to be tested in future electron–ion colliders.
The influence of magnetic field geometry in neutron stars' crustal oscillations
Authors: de Souza Gibran H. , Kemp Ernesto 
Published: December 2019

AbstractIn this work, we have studied oscillations in the crust of a neutron star whose magnetic field has both dipolar and toroidal components; the former extends from the stellar interior to the outer space, and the latter is confined inside the star radius. Our study is based on the solutions we have obtained for perturbations in the star fluid, confined to the crust thickness. Our results are compared to the frequencies observed in the soft gamma repeaters signals.
Eu3+–Eu2+‐doped xAl2O3–ySiO2 and xAl2O3–zMgO composites phosphors
Authors: Guo Qihuang , Wu YuHeng , Wu Yuansheng , Yu Lixin , Gao Zhenyu , Zhong Jianlin , Zou Yingxuan 
Published: December 2019

AbstractIn this paper, the Eu3+–Eu2+ (4%, molar ratio)‐doped xAl2O3–ySiO2 (x = 0–2.5, y = 1–5) and xAl2O3–zMgO (x = 0–1.5, z = 0–3) composites phosphors with different Al2O3 to SiO2 (A/S) and Al2O3 to MgO (A/M) ratios were prepared using a high‐temperature solid‐state reaction under air atmosphere. The effects of the A/S and A/M on luminescence properties, crystal structure, electron spin resonance, and Commission Internationale de l’Eclairage chromaticity coordinates of the samples were systematically analyzed. These results indicated that the different A/S and A/M ratios in the matrix effectively affected the crystal phase, degrees of self‐reduction of Eu3+, and led the relative emission intensity of Eu2+/Eu3+ to change and adjust.
Evaluation, Pitfalls and Recommendations for the “Water Layer Test” for Solid Contact Ion‐selective Electrodes
Authors: Hambly Bradley , Guzinski Marcin , Pendley Bradford , Lindner Ernő 
Published: December 2019

AbstractThe “water layer test” is a crucial validation step of solid‐contact ion‐selective electrodes. It can confirm or contest the claim that the tested electrode is indeed a genuine solid contact electrode without an aqueous film between the ion‐selective membrane and its solid contact. Information about the presence of a water layer is essential for the interpretation of drifts in the electrode potentials commonly experienced with solid contact electrodes. Since its publication, the water layer test has been ubiquitously used, but without a standardized protocol the interpretation (or misinterpretation) of the test results led to uncertainties in the conclusions. Through both experiments and simulations based on theoretical models we have investigated the experimental parameters that can influence the results of the water layer test. We propose guidelines to minimize the possibility of misinterpretation of the results of the water layer test by considering the key factors that affect the shape of transients recorded during the water layer test. Most importantly, we emphasize the importance of allowing sufficient time for conditioning the tested electrode before the water layer test and providing adequate time for equilibration during the experiment. Using a thin ion‐selective membrane and thin solid‐contact layer for the tests is also recommended.
Shear‐wave elastography of the liver in a healthy pediatric population
Authors: Yang Hanning , Sun Yue , Tang Yueyue , Lu Yongping , Hu Bing , Ying Tao 
Published: December 2019

AbstractPurposeThe aim of this study was to determine the elastic modulus values of normal liver tissue in school‐age children by shear wave elastography (SWE) and to study the factors that influence these stiffness measurements.MethodsSix hundred and four school‐age children (295 girls and 309 boys) who were recruited at a hospital and had normal results of specific laboratory tests and imaging studies underwent SWE examinations. The elastic modulus values were obtained in segment V and VI for each subject and comparisons were made between age groups.ResultsThe mean elastic modulus values for school‐age children were 6.3 ± 1.1 kPa for segment V and 6.2 ± 1.1 kPa for segment VI. A positive linear trend in liver stiffness was found for the 6 to 9‐year‐old age group in segments V and VI (R2 = 0.076 vs R2 = 0.085, respectively, P < .05). No statistically significant difference in liver stiffness was found between genders and between segment groups (P > .05).ConclusionSWE is a feasible method to measure liver stiffness in the school‐age population. We established a normal range of liver elastic modulus values in school‐age children, which will provide a basis for evaluating the changes in liver stiffness caused by various diseases.
A generalization of Tuza's conjecture
Authors: Aharoni Ron , Zerbib Shira 
Published: December 2019

AbstractA famous conjecture of Tuza is that the minimal number of edges needed to cover all triangles in a graph is at most twice the maximal size of a set of edge‐disjoint triangles. We propose a wider setting for this conjecture. For a hypergraph let be the maximal size of a collection of edges, no two of which share or more vertices, and let be the minimal size of a collection of sets of vertices, such that every edge in contains a set from . We conjecture that the maximal ratio is attained in hypergraphs for which . This would imply, in particular, the following generalization of Tuza's conjecture: if is 3‐uniform, then . (Tuza's conjecture is the case in which is the set of all triples of vertices of triangles in any given graph.) We show that most known results on Tuza's conjecture go over to this more general setting. We also prove some general results on the ratio , and study the fractional versions and the case of ‐partite hypergraphs.
On DP‐coloring of digraphs
Authors: Bang‐Jensen Jørgen , Bellitto Thomas , Schweser Thomas , Stiebitz Michael 
Published: December 2019

AbstractDP‐coloring is a relatively new coloring concept by Dvořák and Postle and was introduced as an extension of list‐colorings of (undirected) graphs. It transforms the problem of finding a list‐coloring of a given graph with a list‐assignment to finding an independent transversal in an auxiliary graph with vertex set . In this paper, we extend the definition of DP‐colorings to digraphs using the approach from Neumann‐Lara where a coloring of a digraph is a coloring of the vertices such that the digraph does not contain any monochromatic directed cycle. Furthermore, we prove a Brooks’ type theorem regarding the DP‐chromatic number, which extends various results on the (list‐)chromatic number of digraphs.
Effect of bound water on the quality of dried Lentinus edodes during storage
Authors: Yang Wenjian , Pu Haoliang , Wang Liuqing , Hu Qiuhui , Mariga Alfred M , Zheng Huihua 
Published: December 2019

AbstractBACKGROUNDWater absorption is the dominant factor affecting the quality deterioration of dried Lentinus edodes. We therefore analyzed the effect of moisture content and dynamic water status on physical properties of the mushroom stored at water activity (aw), 0.33, 0.43, 0.67, 0.76, and 0.84 for 50 days. Moisture mobility and water status were analyzed using low‐field nuclear magnetic resonance, while hardness and microstructure were determined as texture characteristics. Meanwhile, an electronic nose and headspace solid‐phase micro‐extraction combined with gas chromatography–mass spectrometry (HS–SPME–GC–MS) were used to analyze the flavor properties of dried L. edodes.RESULTSThe results showed that bound water was the dominant water status in dried L. edodes. The content and molecular mobility of bound water increased at aw = 0.67, 0.76, and 0.84. This contributed to discoloration, hardness loss, and microstructure sparsity of dried L. edodes. The increasing content and molecular mobility of bound water aggravated the deterioration of characteristic flavor by reducing acid, aldehyde, and ketone content.CONCLUSIONUnlike immobilized or free water, bound water had a critical influence on the quality deterioration of dried L. edodes during storage. © 2019 Society of Chemical Industry
The recovery properties under load of a shape memory polymer composite material
Authors: Basit A. , L'Hostis G. , Durand B. 
Published: December 2019

AbstractIn many applications, shape memory alloys are being replaced by shape memory polymers as they have some better properties than shape memory alloys. Nevertheless, shape memory alloys can recover under load which shape memory polymers cannot. Shape memory polymers are not capable of giving full recovery even lifting a tiny load. The melting temperature or the glass transition temperature is the transition temperatures to which shape memory polymers are closely heated. Then a deforming force up to a certain position is applied to the heated shape memory polymers. After that shape memory polymer is permitted to cool while keeping it deformed. After the cooling, shape memory polymer obtains the temporary shape which can be recovered by reheating it at the similar transition temperature (glass transition or melting). Consequently, it recovers at its initial state. Shape memory polymer can achieve constrained recovery and unconstrained recovery, nonetheless; under stress, it is partly recovered. In current work, recovery under load has been investigated of an asymmetrical shape memory composite. It is established that it is capable to recover under various loads. Under various loads, it shows full recovery in reference to initial state. The ability to recover under load can be potentially used in diverse applications.
Effect of pre‐processing annealing and ram speed on mechanical properties for low carbon steel processed by constrained groove pressing
Authors: El Mahallawy N. , George P. , Gad E.H. , Abdelhaleem A.M. 
Published: December 2019

AbstractConstrained groove pressing (CGP) has emerged for producing ultra‐fine‐grained materials with distinguished properties. Low carbon steel sheets were subjected to severe plastic deformation by constrained groove pressing process. The effect of pre‐processing annealing temperature, ram speed and number of passes on microstructure, mechanical properties and wear behaviour of the sheets were investigated. The 3 mm thick sheets were deformed by a constrained groove pressing die at ram speeds: 5 mm/min, 10 mm min−1 and 20 mm min−1. Furthermore, the as received sheets were annealed at 600 °C and 900 °C, then deformed at ram speed 20 mm min−1. The annealing temperature 900 °C led to slightly coarser grains, lower strength and larger ductility compared to those obtained after annealing at 600 °C. With lowering the ram speed to 5 mm min−1, the number of passes could be increased to 10 passes while increasing ram speed from 5 mm min−1 to 20 mm min−1 improved the mechanical properties; after 3 constrained groove pressing passes, the ultimate tensile strength increased from 420 MPa to 490 MPa, the hardness from 174 HV 1 to 190 HV 1 and the elongation from 7.6 % to 9.5 %. Finer grains were also obtained by increasing ram speed. Wear resistance was greatly enhanced by constrained groove pressing and by the increase in ram speed.
Experimental and numerical research on high‐temperature thermal insulation performance of lightweight porous ceramic/nanomaterial composite structure
Authors: Ren H.Y. , Wu D.F. , Wu W.J. , Li J.N. , Lin L.J. 
Published: December 2019

AbstractThe thermal protection structure of hypersonic vehicles must meet the design requirements of high efficiency and light weight, and its heating surface must also be able to withstand thermal erosion by high‐speed and high‐temperature airflow. In this paper, a light‐weight porous ceramic material and a lightweight nanoscale thermal insulation material with excellent thermal insulation performance are combined to form an integrated thermal protection structure. Experimental study and numerical simulation of the structure's high‐temperature thermal insulation performance are carried out. The experimental results show that a composite sheet made from a 20 mm‐thick lightweight porous ceramic material and a 10 mm‐thick nanomaterial exhibit a temperature drop of 85 % between its back surface and front surface in four thermal environments (1200, 1000, 800 and 600 °C) at 1800 s. This indicates excellent thermal insulation performance of the composite sheet. In addition, the operating temperature limit (<1000 °C) is obtained through high‐temperature thermal performance tests on single‐layer nanomaterial sheets and scanning electron microscopy results. This provides an important basis for determining and optimizing the thickness ratio of the two materials in composite structure.
Mechanical characterisation of the shear, bending and friction behaviour of bindered woven fabrics during the forming process
Authors: Coutandin S. , Wurba A. , Luft A. , Schmidt F. , Dackweiler M. , Fleischer J. 
Published: December 2019

AbstractA critical process step within the liquid composite moulding constitutes in the preforming of two‐dimensional textile material into a near‐net‐shape and load‐capable fibre structure by stamp forming. This paper presents fundamental material experiments on the shearing behaviour, bending properties and friction behaviour considering the binder quantity and forming temperature. In addition, the influence of the process time on the resulting stability of the preform is examined. The findings indicate that the quantity of the binder as well as the forming temperature and the process time have a great influence on the preform quality.