bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of 316L stainless steel powder size distribution on selective laser melting process
Authors: Du Kaiping , Li Shengfeng , Jie Shtn , Gao Xiangzhou , Yu Yueguang 
Published: December 2019

Abstract
The product quality of selective laser melting (SLM) is closely related to the alloy powder size distribution. The small voidage of fine-sized alloy powder bed is beneficial to improve the density of SLM product. While, the fine-sized alloy powder would result in the poor powder spreading uniformity in the SLM equipment, which leads to the formation of holes in the SLM product. In this work, the 316L stainless steel powder was prepared by a vacuum atomization furnace and sieved into a coarse-sized distribution and a fine-sized distribution. Then, the coarse-sized powder and the fine-sized powder are mixed according to different ratios. The results show that, under the condition of same SLM parameters, the density and strength of the SLM sample gradually decrease, with the increasing amount of fine-sized powder. The main reason for this phenomenon is that the fine-sized powder, with the large specific surface, is easy to bond with the coarse-sized powder. It reduces the fluidity of powder, resulting in the pores and cracks during the SLM layering process. Furthermore, the addition of fine-sized powder to the coarse-sized powder results in a decrease in the elongation of SLM sample. However, with the increase of the addition amount of the fine-sized powder, the residual stress is released due to the formation of a large number of cracks and pores, so that the elongation of SLM sample is slightly increases.
Experimental and simulation study for rewelding defects during the flow process of Semi-solid die casting
Authors: Defu Li , Chen Song , Li Daquan 
Published: December 2019

Abstract
Semi-solid die casting process due to its advantages of compact process, high performance and low cost is widely applied in automobile, communication and other industries for the preparation with high performance aluminum alloy castings. Compared with liquid metal melt, the filling behavior is laminar flow for semi-solid metal melt with higher apparent viscosity. In the process of semi-solid die casting, the semi-solid metal melt from different directions came together, it will lead to “rewelding” defects if with insufficient fusion or uneven slurry state. In this paper, the formation reasons and forms of flow “rewelding” defects are analyzed. By numerical simulation and experimental analysis, the flow state of semi-solid metal melt at the junction of filling frontier is represented, and the state of “rewelding” defect is characterized. The effect of eliminating defects is analyzed by modifying the mold structure, such as redesigning overflow and venting systems at the confluence position. The results show that the microstructure of the “rewelding” defects in the confluence position of the semi-solid metal melts is the segregati12on of solid and liquid phase, gas, oxidation inclusions and other defects. Different semi-solid die casting process will affect the flow state and defect size at the location of different semi-solid metal melt coming together. By means of the process control and the mold structure optimization, “rewelding ” defects can be removed from the product cavity. The aluminum alloy semi-solid die-casting products with high performance are obtained finally.
Magnesium vapor reduction of complex double compounds of molybdenum with tungsten
Authors: Kolosov V N , Miroshnichenko M N , Prokhorova T Yu 
Published: December 2019

Abstract
The process of obtaining powder of the Mo-W alloy by magnesium vapor reduction of MgW
x
Mo1–x
O4 and CaW
x
Mo1–x
O4 oxide compounds (x = 0.3) with a residual inert gas pressure of 2-20 kPa in the temperature range 700-800°C was investigated. Argon or helium was used as an inert gas. Powders of Mo-W alloy with a specific surface area of up to 20 m2g-1 were obtained. When both types of compounds were reduced at a residual pressure in the reactor of more than 5 kPa, spatial separation of the reaction products was observed with removal of magnesium oxide from the reaction zone.
Measurement on the thermal barrier ability of ceramic coatings in a flame thermal shock tester
Authors: Yuan Kang , Hou Weiao , Peng Haoran 
Published: December 2019

Abstract
Ceramic materials are widely used at high temperatures due to their low thermal conductivity. Thermal barrier coatings (TBCs) have been applied in hot sections in industrial gas turbines and air engines. The measurement of the thermal barrier ability of the TBCs is very important for coating property evaluation, that can be done in hot gases with temperature gradient through the coatings. In this study, a flame thermal shock tester was used for such investigation. Thick TBC, containing a MCrAlY bond coat and a YSZ top coat, was sprayed onto a superalloy substrate by air plasma spray (APS) process. In the test, hot flame impacted on the top coat surface with the temperature controlled by an infrared thermometer. A thermocouple was attached onto the backside of the substrate to measure the backside temperature. Therefore, the temperature gradient in the TBC can be evaluated. The thermal barrier ability of the TBCs in different back cooling rate was studied.
Oxidising and carburising catalyst conditioning for the controlled growth and transfer of large crystal monolayer hexagonal boron nitride
Authors: Babenko Vitaliy , Fan Ye , Veigang-Radulescu Vlad-Petru , Brennan Barry , Pollard Andrew J , Burton Oliver , Alexander-Webber Jack A , Weatherup Robert S , Canto Barbara , Otto Martin , Neumaier Daniel , Hofmann Stephan 
Published: December 2019

Abstract
Hexagonal boron nitride (h-BN) is well-established as a requisite support, encapsulant and barrier for 2D material technologies, but also recently as an active material for applications ranging from hyperbolic metasurfaces to room temperature single-photon sources. Cost-effective, scalable and high quality growth techniques for h-BN layers are critically required. We utilise widely-available iron foils for the catalytic chemical vapour deposition (CVD) of h-BN and report on the significant role of bulk dissolved species in h-BN CVD, and specifically, the balance between dissolved oxygen and carbon. A simple pre-growth conditioning step of the iron foils enables us to tailor an error-tolerant scalable CVD process to give exceptionally large h-BN monolayer domains. We also develop a facile method for the improved transfer of as-grown h-BN away from the iron surface by means of the controlled humidity oxidation and subsequent rapid etching of a thin interfacial iron oxide; thus, avoiding the impurities from the bulk of the foil. We demonstrate wafer-scale (2″) production and utilise this h-BN as a protective layer for graphene towards integrated (opto-)electronic device fabrication.
Effects of Q&T parameters on phase transformation, microstructure, precipitation and mechanical properties in a PS-30Cr2Nb pipeline steel
Authors: Guan Jisheng , Yuan Qing , Xiong Zhiqiang , Zhang Qingxiao , Xu Guang 
Published: December 2019

Abstract
The heat treatments with different quenching and tempering temperatures were conducted to clarify the effects of Q&T (quenching and tempering) parameters on phase transformation, microstructure, precipitation, mechanical properties in a PS-30Cr2Nb pipeline steel. Results indicate that the optimum property of tensile strength of 892 MPa and elongation of 19.17% was obtained at a low quenching (950 °C) and low tempering temperature (570 °C). Finer prior austenite grains and carbides contributed to the higher strength. Besides, the content of coarsening carbides increased with tempering temperature and quenching temperature. The increased content of coarsening carbides is responsible for the deteriorative comprehensive performance. In addition, Fe3C particle was gradually substituted by the alloy carbides with the proceeding of tempering by the dynamic assignment of elements.
Heavy metal free thermal stabilizing-flame retarding modifier for plasticized poly(vinyl chloride)
Authors: I Al-Mosawi Ali , Marossy Kálmán 
Published: December 2019

Abstract
Our research aimed to find a new material that can be an efficient heavy metal free flame retardant for plasticized poly(vinyl chloride) comparable to the conventional flame retardants. One of these extraordinary materials is Oxydtron using as an admixture for concrete. Oxydtron showed unexpected efficiency as a flame retardant agent and an excellent heat stabilizer as well. Limiting oxygen index (LOI), static heat stability, Congo-red, and differential scanning calorimetry (DSC) were carried out. The thermal tests proved that Oxydtron is suitable to improve plasticized poly(vinyl chloride) performance at high temperatures applications in terms of flame retarding and thermal stability. Therefore, the positive result obtained by the addition of Oxydtron is reducing of plasticized poly(vinyl chloride) flammability by 25.23%, and increasing its thermal stability as well.
Material characterization and unconventional machining on synthesized Niobium metal matrix
Authors: Sivakandhan C , Babu Loganathan Ganesh , Murali G , Suresh Prabhu P , Marichamy S , Sai Krishnan G , Pradhan Raghuram 
Published: December 2019

Abstract
The Purpose of this work is to develop a niobium based metal matrix alloy through sintering based powder metallurgy technique. The 2, 4 and 6 weight percentage of Titanium Carbide (TiC) is added to the alloy. Various material properties such as hardness, tensile strength, impact strength and density are measured after the addition of TiC particle. The characterization, microstructure and particle size of the developed metal matrix are learnt through Scanning Electron Microscope (SEM) and Energy Dispersive Analysis of x-rays (EDAX). Finally, the synthesized niobium metal matrix is machined by unconventional machining processes namely Ultrasonic Machining (USM) and Laser Beam Machining (LBM) processes. The various input and output parameters have been considered for this experimental work. The most influential parameters on Material Removal Rate (MRR) and Surface Roughness (SR) are found by Analysis of variance. The systematic evaluation of optimal parameters of MRR and SR are carried out by using taguchi approach.
DFT-investigation on anisotropy degree of electronic, optical, and mechanical properties of olivine ZnRE2S4(RE = Er, Tm) compounds
Authors: Batouche M , Seddik T , Uğur S , Uğur G , Messekine S , Vu Tuan V , Khyzhun O Y 
Published: December 2019

AbstractUsing PP-APW method the electronic, optical and mechanical anisotropy of ZnRE2S4(RE = Er, Tm) olivine compounds was investigated. The calculated unit cell parameters are in good agreement compared to the experimental ones. In addition, the study of electronic properties reveals that ZnEr2S4and ZnTm2S4are semiconductors with a direct bandgap of about 2.37 eV and 2.35 eV, respectively. The optical constants such as refractive index, reflectivity, and absorption coefficient have been calculated and analyzed. These constants show a clear anisotropy in the UV region for both compounds caused by the different electron polarizability inx−,y− andz−direction. Moreover, the elastic constants are estimated for the first time for ZnEr2S4and ZnTm2S4indicating that the compounds are mechanically stable and reveal ductility behavior. The direct bandgap, optical absorption, and mechanical stability make ZnEr2S4and ZnTm2S4promising candidates for optoelectronic application.
Characterization, corrosion and failure strength analysis of Al7075 influenced with B4C and Nano-Al2O3 composite using online acoustic emission
Authors: Emmy Prema C , Suresh S , Ramanan G , Sivaraj M 
Published: December 2019

Abstract
This paper aims to establish the mechanical, corrosion and failure analysis using online acoustic emission of Al7075 alloy, Al7075-B4C composite and Al7075- B4C-Al2O3 hybrid composite with different Boron Carbide (B4C) content of 5, 10, 15 & 20% and Nano Aluminium Oxide (Al2O3) content of 2% on a weight basis with the high energy stir casting method. The casted samples have been characterized by x-ray Diffraction (XRD), Thermo gravimetric analysis (TGA/DSC), Energy Dispersive Spectrum (EDS), and Scanning Electron Microscope (SEM). In case of hybrid composite, the hardness and the tensile strength decrease when the content of Al2O3 increases. However, in the present research, the addition of B4C with nano Al2O3 particles in certain proportions has increased the hardness and tensile strength. In addition, the tensile fractographs of the specimens were analysed using SEM. Acoustic Emission (AE) method was used for monitoring the acoustic energy that are released at the time of deformation process and early crack detection. The influence of the volume fraction of the B4C particulates on the microstructural and corrosion characteristics of Al7075- B4C with nano Al2O3 metal matrix composites (MMCs) was also studied. It has been observed from the literature that the direct strengthening of composites occurs due to the presence of hard ceramic phase, while the indirect strengthening arises from the thermal mismatch between the matrix alloy and reinforcing phase during solidification. Based on the database for material properties, the application area of HAMCs has been proposed in the present review. The effects of nanomaterial dispersion in the metal matrix and the formation of interfacial precipitates on these properties are also addressed. Particular attention is paid to the fundamentals and the structure–property relationships of such novel Nano composites.
Solar-driven steam generation on nitrogen-doped graphene in a 2D water path isolation system
Authors: Chen Yuchao , Sha Changchang , Wang Wenju , Yang Fufeng 
Published: December 2019

Abstract
Solar-driven steam generation using photothermal materials is a green and promising approach to address clean water scarcity. In this work, the graphene oxide(GO) was synthesized by an improved Hummers method, and then GO was reduced by hydrothermal method and modified with nitrogen, called as NRGO. Then, we performed UV-VIS-NIR, XRD, Raman, FTIR and SEM characterization. In order to reduce the heat loss of bulk working liquid and improve the solar-to-heat conversion efficiency, the isolation system with 2D water path was used. The efficiency test of steam generation was performed under the solar intensity of 1000 Wm−2 for 1 h, and the photothermal conversion efficiency of reduced graphene oxide (RGO) and nitrogen-doped graphene (NRGO) was 73% and 87%, respectively. It was found that NRGO owned better solar absorption efficiency, lower thermal conductivity and porosity. NRGO was combined with insulated isolated system which can reduce the heat loss of bulk water, to improve photothermal conversion efficiency.
The prominent charge-transfer effects of trinuclear complexes with nominally high nickel valences
Authors: Yamagami K , Imada S , Yamanaka K , Yaji T , Tanaka A , Kouno M , Yoshinari N , Konno T , Sekiyama A 
Published: December 2019

Abstract
Recently synthesized Rh-Ni trinuclear complexes hexacoordinated with sulfur ions, 3-aminopropanethiolate (apt) metalloligand [Ni{Rh(apt)3}2](NO3)
n
(n = 2, 3, 4), are found to be chemically interconvertible between the nominal Ni2+ and Ni4+ states. In order to clarify the origins of their interconvertible nature and the stability of such a high oxidation state as the tetravalency from the physical point of view, we have systematically investigated the local 3d electronic structures of [Ni{Rh(apt)3}2](NO3)
n
by means of soft x-ray core-level absorption spectroscopy (XAS). The experimental data have been reproduced by the single-site configuration-interaction cluster-model simulations, which indicate that the charge-transferred configurations are more stable than the nominal d-electron-number configuration for n = 3, 4 leading to the prominent charge-transfer effects. These are also supported by S K-edge XAS of [Ni{Rh(apt)3}2](NO3)
n
. Our results imply that the found charge-transfer effects have a key role to realize the interconvertible nature as well as the stability of the high oxidization state of the Ni ions.
Light-induced charge transfer at the CH3NH3PbI3/TiO2 interface—a low-temperature photo-electron paramagnetic resonance assay
Authors: Mantulnikovs Konstantins , Szirmai Péter , Kollár Márton , Stevens Jeremy , Andričević Pavao , Glushkova Anastasiia , Rossi Lidia , Bugnon Philippe , Horváth Endre , Sienkiewicz Andrzej , Forró László , Náfrádi Bálint 
Published: December 2019

Abstract
The performance of organic–inorganic metal halide perovskites-based (MHPs) photovoltaic devices critically depends on the design and material properties of the interface between the light-harvesting MHP layer and the electron transport layer (ETL). Therefore, the detailed insight into the transfer mechanisms of photogenerated carriers at the ETL/MHP interface is of utmost importance. Owing to its high charge mobilities and well-matched band structure with MHPs, titanium dioxide (TiO2) has emerged as the most widely used ETL material in MHPs-based photovoltaic devices. Here, we report a contactless method to directly track the photo-carriers at the ETL/MHP interface using the technique of low-temperature electron paramagnetic resonance (EPR) in combination with in situ illuminations (Photo-EPR). Specifically, we focus on a model nanohybrid material consisting of TiO2-based nanowires (TiO2NWs) dispersed in the polycrystalline methylammonium lead triiodide (MAPbI3) matrix. Our approach is based on observation of the light-induced decrease in intensity of the EPR signal of paramagnetic Ti3+ (

S
=
1

/

2

) in non-stoichiometric TiO2NWs. We associate the diminishment of the EPR signal with the photo-excited electrons that cross the ETL/MHP interface and contribute to the conversion of Ti3+ states to EPR-silent Ti2+ states. Overall, we infer that the technique of low-temperature Photo-EPR is an effective strategy to study the transfer mechanisms of photogenerated carriers at the ETL/MHP interface in MAPbI3-based photovoltaic and photoelectronic systems.
MPF–BML: a standalone GUI-based package for maximum entropy model inference
Authors: Quadeer Ahmed A , McKay Matthew R , Barton John P , Louie Raymond H Y 
Published: December 2019

Abstract

Summary
Learning underlying correlation patterns in data is a central problem across scientific fields. Maximum entropy models present an important class of statistical approaches for addressing this problem. However, accurately and efficiently inferring model parameters are a major challenge, particularly for modern high-dimensional applications such as in biology, for which the number of parameters is enormous. Previously, we developed a statistical method, minimum probability flow–Boltzmann Machine Learning (MPF–BML), for performing fast and accurate inference of maximum entropy model parameters, which was applied to genetic sequence data to estimate the fitness landscape for the surface proteins of human immunodeficiency virus and hepatitis C virus. To facilitate seamless use of MPF–BML and encourage more widespread application to data in diverse fields, we present a standalone cross-platform package of MPF–BML which features an easy-to-use graphical user interface. The package only requires the input data (protein sequence data or data of multiple configurations of a complex system with large number of variables) and returns the maximum entropy model parameters.

Availability and implementation
The MPF–BML software is publicly available under the MIT License at https://github.com/ahmedaq/MPF-BML-GUI.

Supplementary information
Supplementary data are available at Bioinformatics online.
A comprehensive analysis of methods for assessing polygenic burden on Alzheimer’s disease pathology and risk beyond APOE
Authors: Altmann Andre , Scelsi Marzia A , Shoai Maryam , de Silva Eric , Aksman Leon M , Cash David M , Hardy John , Schott Jonathan M ,   Alzheimer’s Disease Neuroimaging Initiative
Published: December 2019

Abstract
Genome-wide association studies have identified dozens of loci that alter the risk to develop Alzheimer’s disease. However, with the exception of the APOE-ε4 allele, most variants bear only little individual effect and have, therefore, limited diagnostic and prognostic value. Polygenic risk scores aim to collate the disease risk distributed across the genome in a single score. Recent works have demonstrated that polygenic risk scores designed for Alzheimer’s disease are predictive of clinical diagnosis, pathology confirmed diagnosis and changes in imaging biomarkers. Methodological innovations in polygenic risk modelling include the polygenic hazard score, which derives effect estimates for individual single nucleotide polymorphisms from survival analysis, and methods that account for linkage disequilibrium between genomic loci. In this work, using data from the Alzheimer’s disease neuroimaging initiative, we compared different approaches to quantify polygenic disease burden for Alzheimer’s disease and their association (beyond the APOE locus) with a broad range of Alzheimer’s disease-related traits: cross-sectional CSF biomarker levels, cross-sectional cortical amyloid burden, clinical diagnosis, clinical progression, longitudinal loss of grey matter and longitudinal decline in cognitive function. We found that polygenic scores were associated beyond APOE with clinical diagnosis, CSF-tau levels and, to a minor degree, with progressive atrophy. However, for many other tested traits such as clinical disease progression, CSF amyloid, cognitive decline and cortical amyloid load, the additional effects of polygenic burden beyond APOE were of minor nature. Overall, polygenic risk scores and the polygenic hazard score performed equally and given the ease with which polygenic risk scores can be derived; they constitute the more practical choice in comparison with polygenic hazard scores. Furthermore, our results demonstrate that incomplete adjustment for the APOE locus, i.e. only adjusting for APOE-ε4 carrier status, can lead to overestimated effects of polygenic scores due to APOE-ε4 homozygous participants. Lastly, on many of the tested traits, the major driving factor remained the APOE locus, with the exception of quantitative CSF-tau and p-tau measures.
Association between Anterior Cingulate Neurochemical Concentration and Individual Differences in Hypnotizability
Authors: DeSouza Danielle D , Stimpson Katy H , Baltusis Laima , Sacchet Matthew D , Gu Meng , Hurd Ralph , Wu Hua , Yeomans David C , Willliams Nolan , Spiegel David 
Published: December 2019

Abstract
Hypnosis is the oldest form of Western psychotherapy and a powerful evidence-based treatment for numerous disorders. Hypnotizability is variable between individuals; however, it is a stable trait throughout adulthood, suggesting that neurophysiological factors may underlie hypnotic responsiveness. One brain region of particular interest in functional neuroimaging studies of hypnotizability is the anterior cingulate cortex (ACC). Here, we examined the relationships between the neurochemicals, GABA, and glutamate, in the ACC and hypnotizability in healthy individuals. Participants underwent a magnetic resonance imaging (MRI) session, whereby T1-weighted anatomical and MEGA-PRESS spectroscopy scans were acquired. Voxel placement over the ACC was guided by a quantitative meta-analysis of functional neuroimaging studies of hypnosis. Hypnotizability was assessed using the Hypnotic Induction Profile (HIP), and self-report questionnaires to assess absorption (TAS), dissociation (DES), and negative affect were completed. ACC GABA concentration was positively associated with HIP scores such that the higher the GABA concentration, the more hypnotizable an individual. An exploratory analysis of questionnaire subscales revealed a negative relationship between glutamate and the absorption and imaginative involvement subscale of the DES. These results provide a putative neurobiological basis for individual differences in hypnotizability and can inform our understanding of treatment response to this growing psychotherapeutic tool.