bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatially and temporally non-uniform plasmas: microdischarges from the perspective of molecules in a packed bed plasma reactor
Authors: van ‘t Veer K , van Alphen S , Remy A , Gorbanev Y , De Geyter N , Snyders R , Reniers F , Bogaerts A 
Published: January 2021

Abstract
Dielectric barrier discharges (DBDs) typically operate in the filamentary regime and thus exhibit great spatial and temporal non-uniformity. In order to optimize DBDs for various applications, such as in plasma catalysis, more fundamental insight is needed. Here, we consider how the millions of microdischarges, characteristic for a DBD, influence individual gas molecules. We use a Monte Carlo approach to determine the number of microdischarges to which a single molecule would be exposed, by means of particle tracing simulations through a full-scale packed bed DBD reactor, as well as an empty DBD reactor. We find that the fraction of microdischarges to which the molecules are exposed can be approximated as the microdischarge volume over the entire reactor gas volume. The use of this concept provides good agreement between a plasma-catalytic kinetics model and experiments for plasma-catalytic NH3 synthesis. We also show that the concept of the fraction of microdischarges indicates the efficiency by which the plasma power is transferred to the gas molecules. This generalised concept is also applicable for other spatially and temporally non-uniform plasmas.
Accelerated decomposition of Bi2S3 nanorods in water under an electron beam: a liquid phase transmission electron microscopy study
Authors: Kim Su Yeon , Kim Ji Hyeon , Jeong Taehyeon , Kim Kyung Bin , Kim Hyung Joong , Nam Ki Min , Ahn Sang Jung , Kwon Ji Hwan , Kim Young Heon 
Published: January 2021

Abstract
Evaluating the stability of semiconductor photocatalysts is critical in the development of efficient catalysts. The morphological and microstructural behaviors of nanorod-shaped Bi2S3 semiconductors in aqueous solution were studied using a liquid cell transmission electron microscopy (TEM) technique. The rapid decomposition of Bi2S3 in water was observed under electron beam irradiation during TEM. Rounded bright spots due to a reduction in thickness were observed on the Bi2S3 nanorods at the initial stage of the decomposition, and rounded dark particles appeared outside of the nanorods in the solution, continuing the decomposition. This was confirmed by analyzing the atomic structure of the newly formed small particles, which consisted of an orthorhombic Bi2S3 phase. The stability-related decomposition of the Bi2S3 nanorods was demonstrated by considering the reduction and oxidation potentials of Bi2S3 in an aqueous solution. The effect of water radiolysis by the incident electron during TEM observations on the decomposition process was also determined by considering the time-dependent concentration behavior of the chemical species. Our study therefore reflects a novel route to evaluate the stabilities of semiconductor photocatalysts, which could ultimately solve a range of energy and environmental pollution problems.
3D MXene microspheres with honeycomb architecture for tumor photothermal/photodynamic/chemo combination therapy
Authors: Guo Yaping , Wang Hongshui , Feng Xin , Zhao Yunbo , Liang Chunyong , Yang Lei , Li Mingjun , Zhang Yongguang , Gao Wei 
Published: January 2021

Abstract
The MXene combining high surface area, prominent biocompatibility, and wide near infrared (NIR) absorption has been recognized as one of the most promising materials for tumor therapy. The application of MXene in tumor therapy is negatively affected by the current design methods lack the control of size distribution and the great tendency to agglomerate as well as poor photodynamic therapy. To solve the above problems, we report a facile strategy to process Ti3C2 nanosheets into three-dimensional (3D) structure with honeycomb structure and anti-aggregation properties for synergistic therapy of chemotherapy, photothermal and photodynamic therapy. The 3D MXene is synthesized by spray drying, in which the MXene surface is oxidized to TiO2. The microspheres present prominent NIR light trigger photothermal effect and excellent NIR light photostability, which respond in an on–off manner. Moreover, the microspheres exhibit outstanding drug-loading capability of doxorubicin (DOX) as high as 87.3%, and substantial singlet oxygen generation (1O2) was shown under 808 nm laser and UV light irradiation. Our studies indicate that 3D MXene-DOX could effectively achieve Hela cells killing in vitro, which provides a multifunctional drug delivery platform as a prospective candidate for future combined cancer therapy.
Visible light-induced antibacterial and osteogenic cell proliferation properties of hydrogenated TiO2 nanotubes/Ti foil composite
Authors: Zhao Yu , Lu Ran , Wang Xin , Huai Xiaochen , Wang Caiyun , Wang Yuji , Chen Su 
Published: January 2021

Abstract
We successfully fabricated the hydrogenated TiO2 nanotubes/Ti foil (H-TNTs/f-Ti) composite via one-step anodization and two-step annealing. H-TNTs/f-Ti composite had a higher visible light-induced photoelectric response and more hydroxyl functional groups compared with Ti foil and unmodified TiO2 nanotubes/Ti foil composite, which contributed to limiting the proliferation of Streptococcus mutans and Porphyromonas gingivalis, promoting the proliferation of MC3T3-E1 cell on the hydroxylated surface, and improving the biocompatibility with osteogenic cells. Our study provides a simple and effective method for significantly improving dental implant efficacy.
The experimental solution of the elevator problem
Authors: Lopes Coelho Ricardo 
Published: January 2021

Abstract
This paper combines the physics of the Atwood machine and the classic elevator problem. An Atwood machine equipped with accelerometers is used to determine the acceleration in the bodies’ frames. The product of this acceleration by the mass of the body gives us the weight of the body in that frame. The body that accelerates up weighs more than in the laboratory and the body that accelerates down weighs less. The elevator is then a particular case of this. The upward or downward accelerated motion of an elevator will have the same effect on the acceleration inside the elevator, as the acceleration of the bodies on an Atwood machine has on the accelerations in the bodies’ frames. The weight of a body inside the elevator is given by the product of mass and the inside acceleration, as the weight of the body in its own frame. As this acceleration is greater or smaller than the free fall acceleration in the laboratory, the body’s weight in an elevator will be greater or smaller than the weight in the laboratory.
Shear-lag modelling of surface-bonded magnetostrictive transducers for shear horizontal wave generation in a non-ferromagnetic plate
Authors: Wen Fuzhen , Shan Shengbo , Radecki Rafal , Staszewski Wieslaw J , Cheng Li 
Published: January 2021

Abstract
The fundamental shear horizontal (SH) wave in thin-walled structures shows appealing features for structural health monitoring (SHM) applications. Its efficient generation and reception however remain a critical and challenging issue. Magnetostrictive transducers (MsTs) show proven ability in exciting strong SH waves due to the high piezomagnetic coefficient of the ferromagnetic foil. In this study, to investigate the fundamental SH wave generation using MsTs and their design, a theoretical model is established based on the shear-lag model and the normal mode expansion method. The coupling of an MsT with a host plate is achieved by a bonding layer, whose mechanical property is modelled through the continuous shear stress across the thickness. The theoretical model is validated using finite element simulations in terms of generation mechanism and some typical features associated with the fundamental SH wave component. Meanwhile, wave field is visualized using a 3D Laser scanning vibrometer system. Experimental results within a wide frequency range show a good agreement with the theoretically predicted results. Influences of the coil configuration and bonding conditions are further investigated using the proposed model. The study offers guidelines to system design and optimization for fundamental SH wave generation in views of guided-wave-based SHM applications.
The influence of temperature on levitation properties of CC-tape stacks
Authors: Osipov M , Starikovskii A , Anishenko I , Pokrovskii S , Abin D , Rudnev I 
Published: January 2021

Abstract
This article presents the study of the temperature effect on the levitation characteristics of stacks of CC-tapes from various manufacturers SuperOx, Theva and Sunam. Tapes differ in the values of the critical current density, architecture, and parameters of the metal substrate. Stacks of tapes were assembled from 12 by 12 mm square pieces of CC-tape. The number of elements in the stacks varied from 5 to 70. The dependences of the levitation force Fz
(the vertical component of the force in the system permanent magnet—HTSC stack) on temperature were obtained both in zero field cooling (ZFC) and in field cooling (FC) modes. The measurements were carried out in the temperature range of 32–100 K. We have established that, down to the minimum operating temperatures, a decrease in temperature leads to a continuous increase in levitation force in ZFC mode. In FC mode, the Fz
value tends to saturate after the initial increase in force. Cooling below the boiling point of liquid nitrogen up to 65 K gives a levitation force gain of 5%–10%. At the same time, cooling to 35 K gives an increase in levitation force by 7%–23%. It was found that an increase in the number of elements in the stack from 5 to 70 leads to an increase in the levitation force with a tendency to saturation for all temperatures studied. Excellent agreement between the experimental and calculated dependences of the levitation force on temperature and the number of elements in the stacks is demonstrated. Calculations show that for Sunam tapes, 90% of the levitation force is achieved with a stack thickness of 100 tapes at the boiling point of liquid nitrogen, and with 70 tapes at lower temperatures. The distributions of the magnetic field during the approach/removal of magnets, as well as the distribution of the trapped magnetic flux at different temperatures and numbers of elements in the stacks are modelled.
Combined atomic clock with blackbody-radiation-shift-induced instability below 10−19 under natural environment conditions
Authors: Yudin V I , Taichenachev A V , Basalaev M Yu , Prudnikov O N , Fürst H A , Mehlstäubler T E , Bagayev S N 
Published: January 2021

Abstract
We develop a method of synthetic frequency generation to construct an atomic clock with blackbody radiation (BBR) shift uncertainties below 10−19 at environmental conditions with a very low level of temperature control. The proposed method can be implemented for atoms and ions, which have two different clock transitions with frequencies ν
1 and ν
2 allowing to form a synthetic reference frequency ν
syn = (ν
1 − ɛν
2)/(1 − ɛ), which is absent in the spectrum of the involved atoms or ions. Calibration coefficient ɛ can be chosen such that the temperature dependence of the BBR shift for the synthetic frequency ν
syn has a local extremum at an arbitrary operating temperature T
0. This leads to a weak sensitivity of BBR shift with respect to the temperature variations near operating temperature T
0. As a specific example, the Yb+ ion is studied in detail, where the utilized optical clock transitions are of electric quadrupole (S → D) and octupole (S → F) type. In this case, temperature variations of ±7 K lead to BBR shift uncertainties of less than 10−19, showing the possibility to construct ultra-precise combined atomic clocks (including portable ones) without the use of cryogenic techniques.
Asteroid Observations from the Transiting Exoplanet Survey Satellite: Detection Processing Pipeline and Results from Primary Mission Data
Authors: Woods Deborah F. , Ruprecht Jessica D. , Kotson Michael C. , Main Erin L. , Evans Elizabeth W. , Varey Jacob D. , Vaillancourt John E. , Viggh Herbert E. M. , Brown Joshua J. , Pál András 
Published: January 2021

Abstract
The Transiting Exoplanet Survey Satellite (TESS) is a NASA Explorer-class mission designed for finding exoplanets around nearby stars. TESS image data can also serve as a valuable resource for asteroid and comet detection, including near-Earth objects (NEOs). In order to exploit the TESS image data for moving object detection and potential object discovery, our team has developed an image processing pipeline as part of the Lincoln Near-Earth Asteroid Research (LINEAR) program, sponsored by the NASA NEO Observations Program. The LINEAR-TESS pipeline is currently in operation and reporting asteroid observations to the Minor Planet Center. In this paper we discuss the algorithms and methodology utilized to push the limits of the astrometric accuracy and photometric sensitivity of the TESS instrument for asteroid detection without a priori information on the ephemerides of the objects, and report on observation statistics from the first two years of TESS mission data.
An improved semi-empirical relationship for cluster radioactivity *
Authors: Wang Yanzhao , Xing Fengzhu , Xiao Yang , Gu Jianzhong 
Published: January 2021

Abstract
An improved semi-empirical relationship for cluster radioactivity half-lives is proposed by introducing an accurate charge radius formula and an analytic expression of the preformation probability. Moreover, the cluster radioactivity half-lives for the daughter nuclei around 208Pb or its neighbors and the 12C radioactivity half-life of 114Ba are calculated within the improved semi-empirical relationship. It is shown that the accuracy of the new relationship is improved significantly compared to its predecessor. In addition, the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead and trans-tin nuclei are predicted by the new semi-empirical formula. These predictions might be useful for searching for the new cluster emitters of the two islands in future experiments.
Preparation of Si3N4-YAG mixtures for the spark plasma sintering method
Authors: Andreev P V , Drozhilkin P D , Alekseeva L S , Rostokina E Ye , Karazanov K O , Boldin M S , Balabanov S S 
Published: January 2021

Abstract
In order to obtain ceramics based on Si3N4 with improved physical and mechanical properties, methods of creating composites for their subsequent consolidation by the spark plasma sintering method were investigated. Four different methods of producing mixtures based on the Si3N4 and Al5Y3O12 (YAG) precursor were considered in order to obtain a homogeneous distribution of the YAG sintering additive on the surface of the Si3N4 particles. It is shown that the YAG and Y-Si-Al-O-N phases are formed by co-precipitation, deposition in a gelatin matrix and Pecini methods. The spray drying method does not lead to the formation of the YAG phase. This may indicate a high homogeneity of the YAG coating on the surface of the Si3N4 particles, preventing the growth of crystalline particles.
Degradation of the creep resistance of a Re-containing 10%Cr steel upon creep testing at low applied stress
Authors: Fedoseeva A E , Nikitin I S , Fedoseev A E , Kaibyshev R O 
Published: January 2021

Abstract
New Re-containing steel is a promising material for steam blades of fossil power plants worked at ultra-supercritical parameters of the steam. This steel was subjected to creep testing at 650°C under the applied stresses ranging from 200 to 100 MPa. The steel exhibits excellent creep resistance at high applied stresses; the time to rupture comprises 10,987 hours after the creep test at 650°C/140 MPa. However, a dramatic drop in the creep strength is observed at low applied stresses. A possible reason for this decrease in the creep resistance may be a significant coarsening of the Laves phase particles.
Effect of thermal treatment on the structure and hardness of the laser powder bed-fused Ti-Zr-Nb shape memory alloy
Authors: Kalinicheva V , Sheremetyev V , Letenneur M , Konopatsky A , Prokoshkin S , Brailovski V 
Published: January 2021

Abstract
A new biomedical Ti-18Zr-14Nb (at.%) alloy was processed using the laser powder bed fusion additive manufacturing technology and subjected to post-fusion annealing in the 400 to 900 °C temperature range. The meltpool and grain structure features, the phase composition and hardness of samples fabricated using different laser energy densities and build rates, while having identical printed material densities, were analyzed. It was shown that the microstructure of the alloy differs depending on the printing parameters used. The higher the energy density, the coarser in size and the more elongated towards the build plate grains are formed during the process. Subsequent annealing results in the formation of different structures depending on the printing conditions, and the smaller the as-built grain size, the lower the onset temperature of recrystallization, which starts up to 100 °C lower for the finer grain structure than for the coarser grain structure of this study.
Ultralow-cobalt hard alloys obtained by spark plasma sintering
Authors: Lantsev E A , Chuvil’deev V N , Nokhrin A V , Boldin M S , Malekhonova N V , Blagoveshchenskii Y V , Isaeva N V , Tsvetkov Y V , Andreev P V , Smetanina K E 
Published: January 2021

Abstract
The features of spark plasma sintering (SPS) of plasma-chemical nanopowders WC-(0.3, 0.6, 1) wt.% Co were studied. The SPS process of ultralow-cobalt hard alloys can be sequentially represented as a change of the following mechanisms: rearrangement of particles at lower temperatures (Stage I) → sintering of WC-Co particles due to Coble diffusion creep of cobalt, the intensity of which is determined by the grain boundary diffusion rate (Stage II ) → sintering due to diffusion creep, the rate of which is limited by the bulk diffusion in cobalt (Stage III-1) → sintering of tungsten carbide particles along the intergranular boundaries of WC / WC under conditions of intensive grain growth (Stage III-2). Samples with a high density (96.4-98.4%) and high mechanical properties were obtained (for the WC-0.3% Co hard alloy: Hv ∼ 20.5 GPa, KIC = 7.1 MPa · m1/2).
Method of molecular dynamics investigation of diffusion in solid solutions with consideration of ordering effects on the example of V50W50 and V90W10 alloys
Authors: Lipnitskii A G , Maksimenko V N , Nelasov I V 
Published: January 2021

Abstract
This paper presents the development of methods for the theoretical study of diffusion processes in solid solutions based on molecular dynamics (MD), taking into account the effects of ordering. The influence of concentration and temperature on the features of diffusion characteristics in substitution alloys is studied using the example of solid solutions V50W50 and V90W10. Modeling has shown that the V-W ordering is associated with the separation of plates enriched with tungsten in the planes (100). Vanadium atoms are more mobile and the difference in diffusion coefficients decreases with the equalization of component concentrations and temperature increases.
Methodological approaches to the study of reverse martensitic transformation in metastable austenitic steels
Authors: Panov D O , Smirnov A I , Simonov Y N , Stepanov N D , Salishchev G A 
Published: January 2021

Abstract
Methodological aspects of the high-resolution dilatometry analysis of the reverse α→γ-transformation in cold-worked metastable austenitic steel Fe-0.07C-18.7Cr-9.2Ni-0.6Ti-1.1Mn-0.4Si (wt.%) were considered. It was shown that the reverse α→γ-transformation occurs in the temperature range from AS=520 °C to AF=920 °C. Two consecutive stages corresponding to shear and diffusion transformations were revealed. An abnormal increase in the sample length of the program steel during the reverse α→γ-transformation was found. The recrystallization process also developed during austenitization and was accompanied by a decrease in length of the specimen.
Creep behavior and microstructure of a Ta-added 9%Cr steel with high B and low N contents
Authors: Tkachev E , Belyakov A 
Published: January 2021

Abstract
The creep behavior and microstructure of an advanced a Ta-added 9%Cr steel were investigated. The steel is characterized by increased strength in the long-term creep regime, which can be associated with fine dispersion of (Nb,Ta)(C,N) particles. Strengthening of the studied steel due to the fine MX particles was estimated using the Orowan particle strengthening model.
Creep strength and microstructure of a modified P911-type steel weld joint
Authors: Tkachev E , Belyakov A 
Published: January 2021

Abstract
The creep strength and microstructure of the weld joint of the modified P911-type steel has been studied. The creep rupture time of the welded joint at 650° of 1375 h is close to that of the base metal. The heat affected zone-is found to be the weakest area due to the increased size and relatively high coarsening rate of precipitates. The increased boron content in the weld steel effectively stabilizes the M23(C,B)6 particles and is beneficial for the creep strength of the weld joint in the fusion zone.
Structure and corrosion properties of stainless steel after high-power ion beam processing
Authors: Zhidkov M V , Gazizova M Y , Ligachev A E , Pavlov S K , Remnev G E 
Published: January 2021

Abstract
In this study, the surfaces of AISI 321 stainless steel samples were irradiated with one shot of a high-power ion beam (HPIB) at pulse energy densities of 1 and 3 J/cm2. The surface morphology and structural-phase state in the near-surface layers of the treated samples were analyzed using scanning electron microscopy and electron backscatter diffraction. Additionally, the influence of HPIB processing on the resistance to intergranular corrosion was investigated using electrochemical experiments.
New high-entropy oxide phases with the magnetoplumbite structure
Authors: Zhivulin V E , Trofimov E A , Starikov A Yu , Gudkova S A , Punda A Yu , Zherebtsov D A , Zaitseva O V , Vinnik D A 
Published: January 2021

Abstract
In the studied BaO–SrO–CaO–La2O3–Fe2O3–TiO2–Al2O3–Mn2O3–CoO–In2O3–Ga2O3–Cr2O3 system there were synthesized three new high-entropy magnetoplumbite phases by solid-state sintering in air at 1300, 1350, and 1400 °C.
The average composition of the high-entropy phases obtained at 1350 °C can be described by the formulas:
Ba0.48Sr0.30Ca0.05La0.15Fe1.62Ti1.78Al1.55Mn1.45Co1.11In1.29Ga1.52Cr1.71O19;
Ba0.39Sr0.37Ca0.05La0.18Fe2.88Ti1.60Al1.69Mn1.09Co0.92In1.20Ga1.27Cr1.38O19;
Ba0.37Sr0.29Ca0.05La0.28Fe5.85Ti1.15Al0.97Mn0.74Co0.56In0.85Ga0.94Cr0.97O19.
The data obtained indicate that a significant portion of calcium was not incorporated into the high-entropy phase. This must be taken into account in the course of subsequent experimental work on the creation of homogeneous phases necessary for the study of their electrical and magnetic properties.
Stack fabric felting to get PCM GIIc improvement and LVI tolerance
Authors: Forental G A , Kheruvimov A V , Nikonov A V , Sapozhnikov S B 
Published: January 2021

Abstract
In this work, there was developed a three-axis CNC felting machine with one barbed needle. Felting is a kind of needle-punch technology for joining fabric stack by broken and pulled fibres. The density of needle hits is a valuable factor to make the required shear strength of polymeric composite materials in the specified places. Using the glass-fibre reinforced plastic (GFRP) with plain weave felted fabric, a noticeable decrease in strength with an increase in the needle hits density from 0 to 90 cm−2 is shown. For a laminated GFRP made from a stack of fabrics, it has been shown that the shear strength of the single-lap joint and the interlaminar shear fracture toughness GIIC significantly increase with an increase in the needle hits density. This is important for modern aircraft shells exposed to random low-velocity impacts during ground or flight operations.