bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time saving technique for studying thermal processes in magnetron sputtering of titanium target
Authors: Pavlov V A , Shapovalov V I , Shestakov D S , Rudakov A V , Shabalin A E 
Published: March 2021

Abstract
The kinetics of thermal processes on a substrate during magnetron sputtering of a titanium target has been studied. A technique is proposed for reducing the time of the substrate heating temperature measurement, which is useful in performing extensive experiments in multifactorial problems. The selection criterion for the duration of the observation interval can be the relative error in extrapolating the stationary temperature of the substrate. The technique is universal in nature and allows to reduce the time of a single experiment by a factor of 2 - 3 with an error of no more than 5%.
Tribological properties of CrAlSiC coatings fabricated under various conditions for generating carbon plasma
Authors: Rubshtein A P , Zavalishin V A , Vladimirov A B , Plotnikov S A 
Published: March 2021

Abstract
There were investigated tribological properties of CrAlSiC coatings deposited by two techniques. In both techniques a plasma source of a cathode-arc discharge with Cr-Al-Si composite target served the source of Cr, Al, and Si atoms during coating deposition. A plasma source of a pulsed cathode-arc discharge with graphite cathode and a gas discharge device to generate a non-self-sustained discharge in argon-acetylene mixture have been used for generating carbon plasma in first and second techniques, correspondingly. First coating has a low coefficient of friction. Under frictional action, coating wears out uniformity without chipping. Second coating is less resistant to frictional action.
Magnetron discharge with molybdenum target in argon
Authors: Shestakov D S , Shapovalov V I , Rudakov A V , Shabalin A E , Pavlov V A 
Published: March 2021

Abstract
This paper presents an analysis of the results of original experimental studies of magnetron sputtering of molybdenum cold and hot targets in argon at a pressure of 1-4 mTorr. The current-voltage characteristics (the I-V characteristics) of a magnetron discharge were measured at a discharge current of up to 10 A. It was found that the I-V characteristics of a magnetron with a cold target in the range of 5-6 A contain an inflection point. The intensities of the molybdenum and argon lines in the optical emission spectra of the discharge depend on both the discharge current and the argon pressure. With an increase in the discharge current, regardless of the argon pressure, the process of excitation of argon atoms passes the inflection point and enters a stationary state. The I-V characteristics of the hot target magnetron contain a maximum. The optical spectra of a magnetron discharge with a hot target contain two components: the emission spectrum of the discharge and the emission spectrum of the heated target. The dependence of the target temperature, calculated from these spectra, on the discharge power is described with a high confidence by an exponential. Similarly, the target temperature depends on the discharge current and pressure.
Atomic-molecular and acoustoelectronic processes in a rarefied gas medium
Authors: Simakov I G , Gulgenov Ch Zh , Bazarova S B 
Published: March 2021

Abstract
The features of the interaction of surface acoustic waves with a rarefied gas medium are considered. The relationship between acoustoelectronic and atomic-molecular phenomena accompany the processes of adsorption and desorption of atoms and molecules on the surface of a solid is analyzed. Two types of sorption processes are discussed: adsorption and desorption of gas on a solid surface; adsorption and vapour desorption. In the first process, the temperature of the adsorbent is higher than the boiling point of the corresponding liquid. In the second, the adsorbent temperature corresponds to the area of coexistence vapour and liquid. In each case, the use of vacuum technology in the processes under investigation is noted.
Study of partial pressures of gases in vacuum chamber using multifunctional high-vacuum plant
Authors: Sokolov A N , Rozanov L N , Schedrincky M Z , Bebyakov V M , Vorobev M G , Sinkova V A , Sukharev K N 
Published: March 2021

Abstract
The article studies the mass spectrum of gases inside the vacuum chamber of a multifunctional high-vacuum plant during pumping by different types of high-vacuum pumps. The most effective method to provide the high vacuum inside the cryovacuum systems is to jointly use turbomolecular and cryoadsorption pumps with the ion pump operating periodically.
Test bench to study thermal modes of photodetectors in aerospace applications
Authors: Sokolov A N , Rozanov L N , Schedrincky M Z , Larin M P , Rybas K V , Vorobev M G , Sinkova V A , Koldyba A I 
Published: March 2021

Abstract
The article describes a thermal vacuum bench for studying the thermal modes of photodetectors. The bench allows simulating various thermal impacts on photodetectors in a wide range of temperatures.
Development of a high-voltage divider for kilovoltmeters used in testing and training of electrovacuum devices
Authors: Uhov A A , Kostrin D K , Martsinukov S A 
Published: March 2021

Abstract
The paper discusses the main approaches to the design of high-voltage dividers intended for use in devices that provide voltage control during testing and training of electrovacuum devices. The main circuits of such dividers, namely resistive, capacitive and compensated, are modeled. As a result of research, the optimal parameters of the compensated divider that is most suitable for use in such devices were found, and the design of this device was developed.
Simulation of the spacecraft supersonic jets in vacuum on small-sized laboratory installations
Authors: Zarvin A E , Dubrovin K A , Yaskin A S , Kalyada V V , Khudozhitkov V E 
Published: March 2021

Abstract
The paper presents the experience of modeling supersonic jets of rarefied gases expanding into a vacuum or highly rarefied medium of any given gas composition, as well as interacting flows from nozzle blocks on experimental installations developed at Novosibirsk State University. Examples of visualization of complex sparse flows, results of measurements by electron-beam spectroscopy and molecular-beam mass spectrometry of the density and flows composition under different flow conditions are given. The obtained experimental data validation problems and natural conditions modeling possibilities on small-sized laboratory installations, model and real flows conditions and parameters of similarity are discussed.
An Intrusion Detection Model Based on SMOTE and Convolutional Neural Network Ensemble
Authors: Tian Luyao , Lu Yueming 
Published: March 2021

Abstract
Massive, multi-dimensional and imbalanced network traffic data has brought new challenges to traditional intrusion detection systems (IDSs). The detection performance of traditional algorithms is closely related to feature extractions, which are not effective in the massive and imbalanced data environments. In this paper, we propose an intrusion detection model based on synthetic minority oversampling technology (SMOTE) and convolutional neural network (CNN) ensemble. It converts original traffic vectors into images, designs a CNN structure, and combines SMOTE and CNN ensemble to solve the problem of imbalanced datasets. Using the standard KDD CUP 99 dataset to evaluate the performance of the proposed model and analysing the contribution of features to model decision-making show that the model’s F1 score are better than traditional algorithms in the classes with few samples and the model improves the efficiency of network intrusion detection.
Modeling and Simulation Analysis of Rigid-flexible Coupling Dynamics of Ramming Mechanism Based on Reissner-Mindlin’s Medium-thick Plate Theory
Authors: Li Yong , Qian Linfang , Chen Guangsong 
Published: March 2021

Abstract
In order to obtain the dynamic characteristics of a ramming mechanism, the multi-rigid-body and rigid-flexible coupling dynamic models were established in Recurdyn. Considering the structural characteristics of the link, the deformation motion of the link is described by using the Reissner-Mindlin plate theory, and the dynamic model of a bomb feeder is established considering the influence of non-ideal factors such as transmission clearance, friction and so on, the dynamic characteristics of a bullet-feeding machine are simulated and analyzed. Compared with the multi Rigid body dynamics model, the simulation results of the rigid flexible coupling model are more consistent with the experimental results, in addition to the polygon effect, other factors such as transmission gap and so on are also the causes of the fluctuation of the chain head speed of the ammunition conveyer. In addition, with the periodical movement of the Ammunition Conveyer, the wear between the pin holes of the connecting links will become more and more serious, and the closer you get to the end of the chain, the greater the trend
A Hybrid Gray Wolf Weed Algorithm for Flexible Job-shop Scheduling Problem
Authors: Wang Yi , Song Yu-chuan , Zou Yu-ji , Lei Qi , Wang Xin-kun 
Published: March 2021

Abstract
For the flexible job shop scheduling problem with the goal of makespan, a mathematical model is established and a hybrid algorithm (GIWO) based on gray wolf and invasive weeds is proposed. In this paper, the intrusive weed optimization algorithm is embedded on the basis of the gray wolf algorithm to improve the algorithm’s global search and local search ability. And an effective initial population generation mechanism is added to improve the quality of the initial solution. A variable neighborhood search structure that adaptively changes according to the search is proposed. Finally, other improved gray wolf algorithms are compared with the algorithm in this paper through different benchmark instances. Experimental results show that the proposed algorithm performs better than the other algorithms in effectiveness and superiority. The algorithm can effectively solve the flexible job shop scheduling problem.
Coaxial electrospun biomimetic copolymer fibres for application in diffusion magnetic resonance imaging
Authors: Zhou Feng-Lei , McHugh Damien J , Li Zhanxiong , Gough Julie E , Williams Gareth R , Parker Geoff J M 
Published: March 2021

Abstract

Objective. The use of diffusion magnetic resonance imaging (dMRI) opens the door to characterizing brain microstructure because water diffusion is anisotropic in axonal fibres in brain white matter and is sensitive to tissue microstructural changes. As dMRI becomes more sophisticated and microstructurally informative, it has become increasingly important to use a reference object (usually called an imaging phantom) for validation of dMRI. This study aims to develop axon-mimicking physical phantoms from biocopolymers and assess their feasibility for validating dMRI measurements. Approach. We employed a simple and one-step method—coaxial electrospinning—to prepare axon-mimicking hollow microfibres from polycaprolactone-b-polyethylene glycol (PCL-b-PEG) and poly(D, L-lactide-co-glycolic) acid (PLGA), and used them as building elements to create axon-mimicking phantoms. Electrospinning was firstly conducted using two types of PCL-b-PEG and two types of PLGA with different molecular weights in various solvents, with different polymer concentrations, for determining their spinnability. Polymer/solvent concentration combinations with good fibre spinnability were used as the shell material in the following co-electrospinning process in which the polyethylene oxide polymer was used as the core material. Following the microstructural characterization of both electrospun and co-electrospun fibres using optical and electron microscopy, two prototype phantoms were constructed from co-electrospun anisotropic hollow microfibres after inserting them into water-filled test tubes. Main results. Hollow microfibres that mimic the axon microstructure were successfully prepared from the appropriate core and shell material combinations. dMRI measurements of two phantoms on a 7 tesla (T) pre-clinical scanner revealed that diffusivity and anisotropy measurements are in the range of brain white matter. Significance. This feasibility study showed that co-electrospun PCL-b-PEG and PLGA microfibre-based axon-mimicking phantoms could be used in the validation of dMRI methods which seek to characterize white matter microstructure.
Fabrication and characterization of an injectable reinforced composite scaffold for cartilage tissue engineering: an in vitro study
Authors: Ravari Mojtaba Khozaei , Mashayekhan Shohreh , Zarei Fatemeh , Sayyahpour Forough Azam , Taghiyar Leila , Baghban Eslaminejad Mohamadreza 
Published: March 2021

Abstract
There are limitations in current medications of articular cartilage injuries. Although injectable bioactive hydrogels are promising options, they have decreased biomechanical performance. Researchers should consider many factors when providing solutions to overcome these challenges. In this study, we created an injectable composite hydrogel from chitosan and human acellular cartilage extracellular matrix (ECM) particles. In order to enhance its mechanical properties, we reinforced this hydrogel with microporous microspheres composed of the same materials as the structural building blocks of the scaffold. Articular cartilage from human donors was decellularized by a combination of physical, chemical, and enzymatic methods. The decellularization efficiency was assessed by histological analysis and assessment of DNA content. We characterized the composite constructs in terms of storage modulus, gelation time, biocompatibility, and differentiation potential. The results showed that mechanical behavior increased with an increase in microsphere content. The sample that contained 10% microsphere had an enhanced storage modulus of up to 90 kPa. Biocompatibility and preliminary differentiation investigations revealed that this composite hydrogel might have potential benefits for cartilage tissue engineering.
Anthropogenic warming of Tibetan Plateau and constrained future projection
Authors: Zhou Tianjun , Zhang Wenxia 
Published: March 2021

Abstract
Serving as ‘the water tower of Asia’, the Tibetan Plateau (TP) supplies water resources to more than 1.4 billion people. It is warming more rapidly than the global average over the past decades, affecting regional hydrological cycle and ecosystem services. However, the anthropogenic (ANT) influence remains unknown. Here we assessed the human contribution to the observed TP warming based on coupled climate simulations and an optimal fingerprinting detection and attribution analysis. We show that the observed rapid warming on the TP (1.23 °C over 1961–2005) is attributable to human influence, and particularly, to the greenhouse gases with a contribution of 1.37 °C by the best estimate, which was slightly offset by anthropogenic aerosols. As the multi-model ensemble tends to underestimate the ANT warming trend, the constraint from the attribution results suggests an even warmer future on the TP than previously expected, implying further increased geohazard risks in the Asian water tower.
Perspectives of application of simultaneous water and gas injection for utilizing associated petroleum gas and enhancing oil recovery in the Arctic fields
Authors: Drozdov Alexander , Gorbyleva Yana , Drozdov Nikolay , Gorelkina Evgeniya 
Published: March 2021

Abstract
At present, it is becoming more relevant to use other displacing agents, which are more effective in comparison with waterflooding, for increasing oil and gas condensate deposits component recovery. One of such promising methods is simultaneous water and gas injection. In this article, we present the principal options for using simultaneous water and gas injection in Arctic fields, case study of the Urengoyskoye and Prirazlomnoye fields. Technological schemes for its implementation in the Urengoyskoye field at low reservoir pressures are considered. Filtration studies of oil from reservoir models with water-gas mixtures at various gas contents allow increasing hydrocarbon recovery efficiency by determining the area of rational gas contents. For the conditions of the Prirazlomnoye field, the possibility of using pump-ejector system for the utilization of associated petroleum gas has been established.
Experimental investigation of the tool radius and micro-cutting speed influence on micro-cutting mechanisms for marble based material
Authors: Pjević Miloš , Popović Mihajlo , Tanović Ljubodrag 
Published: March 2021

Abstract
In this paper, a detailed experimental analysis of the effect of tool tip radius and cutting speed on the proposed mechanism of micro-cutting Plavi tok marble was performed. Although Plavi tok marble belongs to extremely brittle materials, experiments have shown that it can be processed in ductile mode (plastic deformation mode), i.e. without the presence of brittle fracturing of the material. Moreover, it has been established that the range of plastic deformation zone is a function of the tool tip radius and the cutting speed. The diamond tools used during the experiments had tip radius values of r = 0.15 and r = 0.2 mm, while cutting speeds were 15 and 25 m s−1. When using tools with higher tip radius values, with increasing cutting speed, the critical penetration depth (ductile-brittle transition) increased from 8.8 to 9.3 μm. On the other hand, tools with lower radius value led to a reduction of the plastic deformation zone range. This declining trend of plastic deformation zone continued during increased cutting speed, with critical penetration depths of 8.6 and 8.3 μm for cutting speeds of 15 and 25 m s−1, respectively. The intensity of lateral/radial destruction in the brittle fracturing mode was also directly dependent on the processing conditions. The reduction was achieved by using tools with a lower value of the tip radius while processing at lower speeds. In this paper, the identification of the components of the cutting force was carried out, whose intensities indicate the occurrence of the brittle destruction within the material.
A closed-loop feature-based FTS patterning and characterisation of functional structured surfaces
Authors: Tong Zhen , Zeng Wenhan , Zhong Wenbin , Jiang Xiangqian 
Published: March 2021

Abstract
To improve the feasibility and efficiency of ultra-precision surface structuring, a closed-loop fast-tool-servo (FTS) surface patterning and measurement system is developed with functional modules of feature-based tool path generation, embedded surface measurement and integrated surface characterisation toolkit. A dedicate controller HUDCNC is developed for the process control of FTS surface patterning and on-machine surface measurement (OMSM). Algorithms are developed for data formatting and transformation of designed patterns into the FTS cutting points (maximum number of 5 million points). The feasibility and performance of the proposed closed-loop FTS machining system are demonstrated by successfully generating typical functional structured surfaces including periodic structures, patterns and tessellations, biological surfaces, profile and character combinations. The results indicate that the feature-based FTS patterning and surface characterisation system provides a promising solution to the design and manufacturing of high-precision functional structured surfaces. The integrated OMSM system and the surface characterisation toolkit allow the fast inspection and quality control of the machined functional surfaces.
In-situ reduction by Joule heating and measurement of electrical conductivity of graphene oxide in a transmission electron microscope
Authors: Hettler Simon , Sebastian David , Pelaez-Fernandez Mario , Benito Ana M , Maser Wolfgang K , Arenal Raul 
Published: March 2021

Abstract
Graphene oxide (GO) is reduced by Joule heating using in-situ transmission electron microscopy (TEM). The approach allows the simultaneous study of GO conductivity by electrical measurements and of its composition and structural properties throughout the reduction process by TEM, electron diffraction and electron energy-loss spectroscopy. The small changes of GO properties observed at low applied electric currents are attributed to the promotion of diffusion processes. The actual reduction process starts from an applied power density of about 2 × 1014 Wm−3 and occurs in a highly uniform and localized manner. The conductivity increases more than 4 orders of magnitude reaching a value of 3 × 103 Sm−1 with a final O content of less than 1%. We discuss differences between the reduction by thermal annealing and Joule heating.
Enhanced single-ion conduction and free-standing properties of solid polymer electrolyte by incorporating a polyelectrolyte
Authors: Mengistie Tewuhibo S , Ko Jang Myoun , Kim Jung Yong 
Published: March 2021

Abstract
A free-standing solid polymer electrolyte (SPE) composed of poly(ethylene oxide) (PEO), bis(trifluoromethanesulfonyl)imide (LiTFSI), and poly(lithium 4-styrenesulfonate) (PLSS) was developed in this work. Thermal analysis indicated that the melting points of PEO were depressed with increasing the salt additives, LiTFSI and PLSS. At the composition of [EO]:LiTFSI:[LSS] = 14:1:1, the SPE exhibited a crystallinity of 7.75%, and a crystallite size of 30.62 nm on the (120) crystallographic plane. [EO] and [LSS] represent the structural unit of PEO and PLSS, respectively. This SPE also exhibited an ionic conductivity (σ) of 1.70 × 10−5 S cm−1 at 25 °C and 1.04 × 10−4 S cm−1 at 45 °C. For analyzing the temperature dependence of σ, the Vogel-Tammann-Fulcher equation was employed. Resultantly, a pseudo activation energy (E

a
= 0.1552 eV), a prefactor (A = 206.0338 S cm−1 K1/2), and an empirical constant (B = 1800.5879 K) were obtained using the optimized [EO]:[Li+] = 7:1 complex. The SPE showed an electrochemical stability window of ∼4.7 ± 0.1 V versus Li/Li+. Through DC polarization and AC impedance, the Li-ion transference number of 0.66 was obtained at 70 °C. Finally, when a Li/SPE/LiFePO4 cell was prepared, the device exhibited a discharge capacity of 121 mAh g−1 at 50 °C with a coulombic efficiency close to 100%.
Corruption: An Impediment to Delivering Pathology and Laboratory Services in Resource-Limited Settings
Authors: Glynn Emily H , Amukele Timothy , Vian Taryn 
Published: March 2021

Abstract

Objectives
Corruption is a widely acknowledged problem in the health sector of low- and middle-income countries (LMICs). Yet, little is known about the types of corruption that affect the delivery of pathology and laboratory medicine (PALM) services. This review is a first step at examining corruption risks in PALM.

Methods
We performed a critical review of medical literature focused on health sector corruption in LMICs. To provide context, we categorized cases of laboratory-related fraud and abuse in the United States.

Results
Forms of corruption in LMICs that may affect the provision of PALM services include informal payments, absenteeism, theft and diversion, kickbacks, self-referral, and fraudulent billing.

Conclusions
Corruption represents a functional reality in many LMICs and hinders the delivery of services and distribution of resources to which individuals and entities are legally entitled. Further study is needed to estimate the extent of corruption in PALM and develop appropriate anticorruption strategies.