bluuebunny/crossref_metadata_2025_split huggingface dataset:
Planning of an experimental research of the organization of townhouses’ construction
Authors: Svintsov A P , Abd Noor A A 
Published: November 2020

Abstract
One of the most important ways in improving the research’s efficiency is an experiment’s planning. The aim of the study is to identify and study various factors that can affect the productivity of brick layers during bricklaying of townhouses in Iraq. Visual observation, timing and photographs of the working day were carried out during eight working weeks. In the process of daily monitoring, causal relationships of the formation of downtime and overtime work of bricklayers were identified. The most significant factors are untimely delivery of materials and alteration of performed work. The data obtained are the basis for the development of a mathematical model of labor productivity indicators. An analysis of the data on the functioning of the construction technological system for erecting brick walls of buildings shows that its states can be modeled by regular Markov processes. The data obtained are the basis for the development of a mathematical model of labor productivity indicators.
Properties of metallic materials near the edges of fatigue crack
Authors: Kornilova A V , Zaya Kyaw , Paing Thet , Dobrolyubova M F 
Published: November 2020

Abstract
This paper discusses the condition in the magnetic and mechanical properties of metal materials near the edges of a fatigue crack (samples example – steel20). On the special samples with straight fatigue cracks, the coercive force and hardness were measured near the crack edges. The coercive force drop on the crack was 25%. Therefore, if the magnetic properties of ferromagnetic material fall during the survey, this means that there is a crack in the structure being examined, which is not always detected visually or by non-destructive testing methods with a different physical basis. The obtained results of hardness measurements allowed us to formalize the dependence of the straight crack depth on the drop in hardness near its edges relative to the same parameter in the defect-free section. By calculating and experimentally, the relationship angle between normal and the tangent to the surface of crack inclinationswas identified and formalized. The results of the work can be used in the technical diagnostics of engineering objects.
Synthesis of core-shell Al/Al2O3 composite through aluminum powder oxidation in hot water and its characterization
Authors: Ambaryan G N , Vlaskin M S , Shkolnikov E I , Zhuk A Z 
Published: November 2020

Abstract
Simple and potentially energy efficient way for synthesis of Al/Al2O3 composites is described. Synthesis method is based on aluminum powder oxidation in water at 100-200 °C and following drying and calcination at 600 °C. Aluminum powder with average size of about 40 urn that is currently applied in additive manufacturing was used. Present work was devoted to the study of oxidation degree of aluminum and so the propagation depth and structure of Al2O3 shell in composite’s matrix. AI/Al2O3 composites were produced in different regimes with different maximum temperature and duration of the process of aluminium oxidation in water. Aluminum oxidation degree and aluminium content in obtained Al/Al2O3 were changed in the range from 5.5 % and 90.1 % to 21.3 % and 66.2 % respectively. The size of single crystals of Al2O3 in shell was changed from about 6 nm to 200 nm and the thickness of Al2O3 shell was changed from about 400 nm to 1000 nm by changing the regime for Al/Al2O3 composite production. Experimental results showed that Al2O3 shell was well clutched with aluminum core. Shell structure had cracks aroused by calcination process. Size distribution for obtained composites was very close for that of initial aluminum powder. All of these characteristics recommend the obtained Al/Al2O3 composites for additive manufacturing.
Effect of high pressure processing in the formation of castings of aluminum alloys
Authors: Batyshev K A , Yu Malkova M , Zadiranov A N , Zaya Kyaw 
Published: November 2020

Abstract
The effect of high pressure on the formation conditions of aluminum castings has been investigated. It was established experimentally that the crystallization of castings under high mechanical pressure proceeds at a higher temperature difference across the cross section than at atmospheric pressure. The cooling rate of a cylindrical casting in various zones on the section, which is characteristic for cooling alloy in the crystallization range, is determined. The formula for calculating the solidification time of a casting and the time of its holding pressure during piston compression is recommended. The influence of the scale factor on the solidification time of cylindrical castings is considered. It is shown that with increasing height at a constant diameter of the casting, the relationship between the solidification time and diameter of the casting is linear. It has been experimentally established that the solidification coefficient of an alloy depends on its thermophysical properties of the alloy and the applied pressure. Its value increases with decreasing silicon content in the alloy and increasing pressure. The pressure significantly reduces the difference in the values of the solidification coefficient of castings from alloys of different compositions.
Monolayer MoS2 on sapphire: an azimuthal reflection high-energy electron diffraction perspective
Authors: Xiang Yu , Sun Xin , Valdman Lukas , Zhang Fu , Choudhury Tanushree H , Chubarov Mikhail , Robinson Joshua A , Redwing Joan M , Terrones Mauricio , Ma Yuan , Gao Lei , Washington Morris A , Lu Toh-Ming , Wang Gwo-Ching 
Published: November 2020

Abstract
Molybdenum disulfide (MoS2) on the c-plane sapphire has been a very popular system to study in the two-dimensional (2D) materials community. Bottom-up synthesis of monolayer (ML) MoS2 with excellent electrical properties has been achieved on sapphire by various methods, making it a very promising candidate to be used in the next generation nano-electronic devices. However, large-area ML MoS2 with comparable quality as the relatively small size exfoliated ML remains quite a challenge. To overcome this bottle neck, a comprehensive understanding of the structure of the as-grown ML material is an essential first step. Here, we report a detailed structural characterization of wafer-scale continuous epitaxial ML MoS2 grown by metalorganic chemical vapor deposition on sapphire using an azimuthal reflection high-energy electron diffraction (ARHEED) technique. With ARHEED we can map not only 2D but also 3D reciprocal space structure of the ML statistically. From the oscillation in the ARHEED intensity profile along the vertical direction of the ML, we derived a real space distance of ~3 Å at the interface of ML and sapphire. Quantitative diffraction spot broadening analyses of the 3D reciprocal space map reveals low density defects and a small angular misalignment of orientation domains in ML MoS2. Based on atomic force microscopy height distribution analysis, cross-section scanning transmission electron microscopy, and density functional theory calculations, we suggest that there exists a passivation layer between MoS2 ML and sapphire substrate. This ARHEED methodology also has been applied to ML WS2 and is expected to be applicable to other ML transition metal dichalcogenides on arbitrary crystalline or non-crystalline substrates.
Study on precipitates in AgGaSe2 single crystal grown by vertical gradient freezing method
Authors: Yang Deng-Hui , Cao Xin-Ling , Yang Ling , Zhou Yong-Ling 
Published: November 2020

Abstract
In this study, AgGaSe2 single crystal was successful grown by vertical gradient freezing method. Meanwhile, the precipitates on AgGaSe2 single crystal were investigated by x-ray photoelectron spectroscopy (XPS). This technique was recommended as a practicable method to study the precipitates while they are difficult to be detected by other measurements owing to their components and fairly low content. In addition, Energy Disperse Spectroscopy (EDS) and x-ray diffraction (XRD) were employed to characterize the quality of the as-grown AgGaSe2 single crystal. The EDS results indicate a slight deviation from stoichiometric ratio along growth defects. The XRD results manifest that AgGaSe2 crystal has single phase and high purity. The XPS results indicate that precipitates exist on as-grown AgGaSe2 single crystal mainly in the form of Ga2Se3. Ga2O3 and Ag2O were detected by XPS on the polished surface of the as-grown crystal wafer which was regarded as an oxide layer. The study on precipitates may provide important reference for growth process improvement and post-treatment to obtain high quality AgGaSe2 single crystal.
Adsorptive defluoridation from aqueous solution using a novel blend of eggshell powder and chitosan nanofibers
Authors: Abbasi Aamir , Memon Sheeraz Ahmed , Qureshi Raja Fahad , Mehdi Mujahid , Khatri Muzamil , Ahmed Farooq , Khatri Zeeshan , Kim Ick Soo 
Published: November 2020

Abstract
Groundwater mostly contains many impurities thus can not be consumed as drinking water directly. The acceptable limit of fluoride in drinking water is 0.5–1.5 mg l−1 recommended by World Health Organization (WHO). In this research, a novel nanofiber hybrid; based on Chitosan (CTS) and Eggshell (EGG) was prepared via electrospinning technique and investigated for deflouridation from aqueous solution. SEM images reveal bead-free, smooth morphology and the FTIR confirmed the presence of chitosan and egg within the novel nanofiber blend. The defluoridation efficiency was assessed by varying the different parameters like pH, mass of nanofibers, contact time and initial concentration for adsorption. Studies revealed that CTS/EGG nanofibers hybrid shows incredible adsorption efficiency of 86%. Furthermore, isotherm studies show that the Langmuir isotherm model was well fitted for both CTS and CTS/EGG nanofibers.
Effect of Sn addition on the microstructure and mechanical properties of AZ31 alloys
Authors: Ma Jiaxuan , Wei Qi , Le Taihe , Wang Jinhui , Jin Peipeng 
Published: November 2020

Abstract
An Mg-3Al-1Zn-xSn (x = 0, 3, 6, 9) alloy was prepared by die-casting and analyzed by XRD, SEM, and EBSD. The microstructure, second phase, and grain orientation of the AZT31x alloy were characterized. As the Sn content increased from 3 wt.% to 9 wt.%, the tensile and yield strength of the alloy were effectively improved. With the addition of Sn, the grain size of alloys decreases gradually blocking the dislocation by the grain boundary and the dispersion of the Mg2Sn second phase in the AZT31x(x = 3, 6, 9) alloys contributes to the strength via grain boundary pinning. According to theoretical analysis and calculation, the high strength of AZT319 alloy is partly attributed to the grain fine strengthening

σ

H

P

=
13.76

Mpa

) and second phase strengthening

Δ
σ
=
9.27
∼
12.67

MPa

.

The total increased strengthening value is lower than experimental value (

Δ
σ
=
31.82

MPa

). The ratio about

τ

p
r
i
s
m

/

τ

b
a
s
a
l

and

τ

c
+
a

/

τ

b
a
s
a
l

in die-cast alloys tensioned to 0.08 deformation gradually decrease, which can reflect that high-Sn content contributes to the strain hardening behavior. The ductility of AZT313 alloy was lightly improved due to the {10-12} tensile twins. When excessive Sn was added, the Mg2Sn second phase coarsened and acted as the nucleus of micro-cracks during the stretching process, thereby reducing the ductility of the alloy.
Study of gadolinium aluminate nanoparticles with perovskite structure prepared by citric acid chelation method
Authors: Dai Shiyu , Wang Gang , Qi Pengyuan , Xu Xiaochen , Jiang Lili , Zhong Jingyu , Yuan Shuo , Wang Lei 
Published: November 2020

Abstract
Gadolinium aluminate (GdAlO3, GAP) is a rare earth compound with perovskite structure. Its optical isotropic structure prevents the defects of refractive index difference in any direction. GAP has unique and excellent properties in electricity, magnetism, luminescence and catalysis, especially as a high-quality luminescent matrix material. Sol-gel method has the advantages of accurate control of chemical composition, particle size and purity of products. The main preparation parameters include chelating agent concentration, alcohol water ratio, calcination temperature and so on. In this paper, the citric acid chelating agent was used to prepare gadolinium aluminate nanoparticles by sol-gel method, thermogravimetry-differential thermal analysis (TG-DTA), x-ray diffraction (XRD) and scanning electron microscope (SEM) were employed to analyze the effects of chelating agent, dispersant, solvent and calcination temperature on the phase and morphology changing in precursor and final product. The results show that GAP nanoparticles with high degree of crystallinity, nearly spherical morphology and 60–100 nm particle size can be obtained at the molar ratio of citric acid to cationic of 1:1, the ammonium citrate to citric acid of 1.5:1 and the calcination temperature of 900 °C for 4 h. When the calcination temperature is higher than 1100 °C, a new phase of Gd3Al5O12 (GdAG) will be formed with calcination neck shape.
Percolative magnetic correlation and competing-antiferromagnetism in highly oriented pyrolytic graphite with hexagonal Moiré superlattices at the magic-angle
Authors: Boi Filippo S , Gao Shuai , He Yi , Wang Shanling 
Published: November 2020

Abstract
Occurrence of magnetic-correlation-phenomena in multi-layered carbon-materials has recently attracted an important attention for applications in magnetic devices and spintronics. In this study, exfoliated highly-oriented-pyrolytic-graphite (HOPG) lamellae exhibiting hexagonal-Moiré-superlattices, with periodicity of ∼13 nm (1st category, θ
rot ∼ 1.09° ) and ∼36 nm (2nd category, θ
rot ∼ 0.39°) were investigated. Raman-spectroscopy evidenced weak D, D’ and intense G bands. In 1st category, magnetization versus field, ZFC- FC magnetic-curves from 2 K to 300 K and T-ESR revealed presence of uncorrelated and correlated ferromagnetic clusters at T* ∼ 150 K together with a critical transition at Tc ∼ 50 K, compatible with percolative-ferromagnetic-correlation. Comparative measurements on the 2nd category, revealed an analogue trend, with at T* ∼ 50–60 K together with an irreversibility at Tc ∼ 40 K, indicative of competing ferromagnetic/antiferromagnetic-correlations.
Boron doping in gallium oxide from first principles
Authors: Lehtomäki Jouko , Li Jingrui , Rinke Patrick 
Published: November 2020

Abstract
We study the feasibility of boron doping in gallium oxide (Ga2O3) for neutron detection. Ga2O3 is a wide band gap, radiation-hard material with potential for neutron detection, if it can be doped with a neutron active element. We investigate the boron-10 isotope as possible neutron active dopant. Intrinsic and boron induced defects in Ga2O3 are studied with semi-local and hybrid density-functional-theory calculations. We find that it is possible to introduce boron into gallium sites at moderate concentrations. High concentrations of boron, however, compete with the boron-oxide formation.
High-fidelity imaging through multimode fibers via deep learning
Authors: Zhao Jun , Ji Xuanxuan , Zhang Minghai , Wang Xiaoyan , Chen Ziyang , Zhang Yanzhu , Pu Jixiong 
Published: November 2020

Abstract
Imaging through multimode fibers (MMFs) is a challenging task. Some approaches, e.g. transmission matrix or digital phase conjugation, have been developed to realize imaging through MMF. However, all these approaches seem sensitive to the external environment and the condition of MMF, such as the bent condition and the movement of the MMF. In this paper, we experimentally demonstrate the high-fidelity imaging through a bent MMF by the conventional neural network (CNN). Two methods (accuracy and Pearson correlation coefficient) are employed to evaluate the reconstructed image fidelity. We focus on studying the influence of MMF conditions on the reconstructed image fidelity, in which MMF for imaging is curled to different diameters. It is found that as an object passes through a small bent diameter of the MMF, the information of the object may loss, resulting in little decrease of the reconstructed image fidelity. We show that even if MMF is curled to a very small diameter (e.g. 5 cm), the reconstructed image fidelity is still good. This novel imaging systems may find applications in endoscopy, etc.
Effect of camera position on egocentric localisation with Simulated Prosthetic Vision
Authors: Prabhu Deepa , Wise Lisa , MacMahon Clare , De Man Marten , Petoe Matthew , McCarthy Chris 
Published: November 2020

Abstract

Objective: The positioning of the external camera in current designs of retinal prostheses may affect the egocentric spatial frame of reference and lead to pointing and localisation errors. The present simulated prosthetic vision (SPV) study investigated the immediate effects of four camera positions: (i) centre-mounted (CM), (ii) head-mounted (HM), (iii) left-mounted (LM), (iv) right-mounted (RM) on egocentric localisation. Approach: Fifteen sighted participants performed a pointing task while viewing the stimulus through a simulation of Bionic Vision Technologies’ 44-channel retinal prosthesis. Pointing responses were recorded immediately after exposure to different camera positions and prior to adaptation. The direction and magnitude of pointing errors and associated head movement behaviour were analysed using linear mixed effects analysis. Main results: Our results showed lower errors for medial camera positions (CM and HM) and overall improved accuracy and precision for CM position. Head orientation was found to largely influence the direction of pointing. There was a high positive correlation between direction of head orientation and direction of pointing with CM and HM camera positions, suggesting medial camera positions facilitated intuitive head orientation cues that are important for reliable egocentric direction estimation. Significance: The empirical evidence derived from the present SPV study offers practical guidance to reduce the effect on spatial dissociation of camera position in localisation tasks and inform design of future prosthetic vision devices and improve rehabilitation approaches.
An XFEM-based computational homogenization framework for thermal conductivity evaluation of composites with imperfectly bonded inclusions
Authors: Erkmen E , Malek S , Ayranci C 
Published: November 2020

Abstract
In many engineering applications, such as thermal coating and structural insulation, 2D modelling is deemed sufficient to identify design parameters. For the effective thermal conductivity evaluation of heterogeneous composites, a 2D computational homogenization procedure is developed in this study. The inclusions are distributed randomly within the plane. The boundary conditions tested for homogenization procedure introduced include the periodic temperature, uniform temperature, and uniform flux boundary conditions. The bond between the inclusions and the surrounding matrix is assumed imperfect allowing partial heat transfer at the interface. Randomly distributed inclusions can be introduced without altering the underlying regular mesh of the matrix by using the XFEM, providing an efficient way of introducing the inclusions. Implementation details of the proposed computational homogenization scheme based on the XFEM are provided. The results are validated by comparisons with available analytical solutions. Effect of assumed boundary conditions on the results are shown. Parametric studies illustrate the influence of the interface properties, volume ratio of inclusions as well as the distributions of the inclusions on the effective thermal conductivity of composites.
Emerging antibody-based therapeutics against SARS-CoV-2 during the global pandemic
Authors: Sun Yaping , Ho Mitchell 
Published: November 2020

AbstractSARS-CoV-2 antibody therapeutics are being evaluated in clinical and preclinical stages. As of 11 October 2020, 13 human monoclonal antibodies targeting the SARS-CoV-2 spike protein have entered clinical trials with three (REGN-COV2, LY3819253/LY-CoV555, and VIR-7831/VIR-7832) in phase 3. On 9 November 2020, the US Food and Drug Administration issued an emergency use authorization for bamlanivimab (LY3819253/LY-CoV555) for the treatment of mild-to-moderate COVID-19. This review outlines the development of neutralizing antibodies against SARS-CoV-2, with a focus on discussing various antibody discovery strategies (animal immunization, phage display and B cell cloning), describing binding epitopes and comparing neutralizing activities. Broad-neutralizing antibodies targeting the spike proteins of SARS-CoV-2 and SARS-CoV might be helpful for treating COVID-19 and future infections. VIR-7831/7832 based on S309 is the only antibody in late clinical development, which can neutralize both SARS-CoV-2 and SARS-CoV although it does not directly block virus receptor binding. Thus far, the only cross-neutralizing antibody that is also a receptor binding blocker is nanobody VHH-72. The feasibility of developing nanobodies as inhaled drugs for treating COVID-19 and other respiratory diseases is an attractive idea that is worth exploring and testing. A cocktail strategy such as REGN-COV2, or engineered multivalent and multispecific molecules, combining two or more antibodies might improve the efficacy and protect against resistance due to virus escape mutants. Besides the receptor-binding domain, other viral antigens such as the S2 subunit of the spike protein and the viral attachment sites such as heparan sulfate proteoglycans that are on the host cells are worth investigating.
Reduced Remodeling Biomarkers Tissue Expression in Nanotextured Compared With Polyurethane Implants Capsules: A Study in Rats
Authors: Pontes Gisela Hobson , Carneiro Filho Fernando Sérgio Mendes , Vargas Guerrero Luis Alejandro , Lipinski Leandro Cavalcante , de Noronha Lucia , Silva Eduardo Nascimento , Serra-Guimarães Fernando 
Published: November 2020

Abstract

Background
In the biological response to biomaterials, the implant shell plays a key role in immune and inflammatory reactions. We hypothesized that the capsules formed around nanotextured implants exhibit an immunohistochemical behavior different to those formed around polyurethane implants.

Objectives
The aim of this study was to evaluate through immunohistochemistry markers the capsules formed around nanotextured and polyurethane implants.

Methods
Sixty albino female Wistar rats were divided into 2 groups (nanotextured and polyurethane), with 30 animals in each group. A mini silicone implant was inserted on the back of the animals. After a predetermined period, the animals were killed, and the capsules formed around the implants were studied. The capsules in the 30-, 60-, and 90-day subgroups were analyzed via immunohistochemistry to detect markers for fibroblast α smooth muscle actin (α-SMA), transforming growth factor β (TGF-β), cluster of differentiation 34 (CD34), and CD68, via picrosirius staining to determine the density of type I and III collagen fibers and via hematoxylin and eosin staining to assess capsule thickness. A Wilcoxon-Mann-Whitney test was used to compare the groups, and a Kruskal-Wallis test was used to compare the subgroups.

Results
Lower α-SMA, TGF-β, CD34 and CD68 immunoexpression was observed in the nanotextured 30- and 60-day subgroups than in the corresponding polyurethane subgroups. In the 90-day subgroup, more pronounced α-SMA and CD34 immunoexpression was observed in the nanotextured group; however, TGF-β and CD68 immunoexpression remained lower. The nanotextured implants showed reduced capsular thickness and greater formation of type I collagen in all the analyzed subgroups.

Conclusions
Nanotextured implants led to reduced immune and inflammatory reactions compared with polyurethane implants according to all analyzed variables.