bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Evaluation Model of Grouting Effect in Weak and Water-Rich Stratum
Authors: Jie Cai 
Published: January 2021

Abstract
The development of underground engineering promotes the development of grouting technology, but due to its particularity, the research of grouting theory lags behind the application requirements of actual engineering, and the evaluation of grouting effect is a weak link in grouting theory. Grouting effect is influenced by many factors with uncertainty and nonlinear characteristics. Four factors, anti-inference method of slurry filling rate, displacement monitoring method, exposure observation method, core method in access hole, were proposed, and the corresponding quantitative indexes were determined. In this study, a novel evaluation model was developed using analytic hierarchy process and ideal point method to study grouting effect in weak and water-rich stratum. The results show that this method is feasible. With its strong operability, the proposed method provides a new means to evaluate grouting effect.
Discussion on evaluation method of water energy in strong water drive gas reservoir
Authors: Li Guohui 
Published: January 2021

Abstract
In the process of gas reservoir development, as the pressure of gas reservoir decreases, water will invade into the gas reservoir and form a certain scale of water body, so it is very necessary to know the water body energy correctly. This paper takes strong water drive gas reservoir as an example, and uses equation of state method, pressure drop curve method and material balance method respectively to complete the water body energy evaluation of this block, so as to find the water body energy evaluation method suitable for strong water drive gas reservoir, which plays an important role in implementing water control measures.
The Calibration of an Array Induction Logging Tool in half-space
Authors: Wang Zhao , Zhang Peipei 
Published: January 2021

Abstract
Array induction logging tools are currently relatively widely used resistivity logging tools. The scale of array induction logging tools includes workshop scale and half space scale. The main purpose of the workshop scale is to use the ring scale to determine the instrument constant (K value). The half-space scale determines the system error of the instrument coil, that is, the basic value. The longest sub-array of the array induction logging tool MIT has a detection depth of 2.5m in the air. Signals over 14m account for 10%, and signals over 28m account for 5%. The ground conductivity must be considered during the half-space calibration process. Influences. This topic studies the method of eliminating grounding conductivity and coil system errors. The completion of the subject will be of great significance to the accurate calibration of the instrument measurement signal.
Research on Sustainable Utilization of Rural Resources in Tourism Development in Mountain Area
Authors: He Jianbo , Zhu Zi’ang 
Published: January 2021

Abstract
In the new era, with the acceleration of urbanization, the ecological environment is increasingly destroyed and deteriorated, and people's desire to get close to nature is increasingly strong. To meet this demand, people combine agriculture with leisure tourism, giving birth to sightseeing agriculture. The sightseeing agriculture in most mountain areas integrates leisure vacation, ecological tour, experience participation, popular science education and integrates farming culture into it. Taking Mingyue Mountain of Jiangxi province as example, this paper analyzes the problems existing in exploitation and utilization of rural resources in tourism development in mountain area, and puts forward some countermeasures for the further sustainable utilization of rural resources so as to make agricultural tourism in mountain areas more attractive.
Technological factors affecting the occurrence of foot diseases in high-producing cows
Authors: Rukol V. M. , Medvedeva E. G. , Kochetkov A. V. , Solyanchuck P. V. , Nikolaevich Borisik Roman 
Published: January 2021

Abstract
In conditions of intensification of dairy cattle breeding, limb diseases in highly productive cattle are widespread. On the farms under investigation, diseases of digital and hoof diseases range from 60.5 to 85.6%. Based on the work we have done, we consider that the main causes that lead to the development of hoof diseases in cows are failures associated primarily with feeding cattle, non-compliance with zoohygienic standards and technological factors (design features of premises and recreation areas, mismatch of floors and floor coverings of premises, lack of isolated rooms for medical care and maintenance of operated cows with purulent-necrotic diseases). The lack of daily orthopedic work on functional hoof trimming, care and treatment of cows with digital and hoof diseases. Improper technological use of preventive foot baths also affects the spread of limb diseases, reduces the period of production use of animals and leads to their premature loss.
FDS simulation of fire spreading on facade heat insulating system
Authors: Yakovchuk Roman , Kuzyk Andriy , Kagitin Olexander , Ivanusa Andriy , Yemelyanenko Sergiy 
Published: January 2021

Abstract
The main purpose of this work was to determine the parameters of the fire test of the exterior wall construction with facade heat insulation and plaster to spread the fire by FDS simulation, to reproduce the real conditions of fire test and to verify the developed model by comparing the obtained data with experimental results. Satisfactory error was obtained when measuring temperatures experimentally and by computer simulation during experiments.
An experimental study of the spread of fire on the surface of external walls with facade insulation and computer simulation of full-scale tests using computer methods of gas hydrodynamics. Using computer simulation of the parameters of the fire test of the facade insulation system for the spread of fire in the FDS environment, numerical and graphical indicators were obtained that characterize the process of occurrence, spread and development of fire by the surface of the facade insulation system. Computer modelling of fire dynamics using FDS numeric tool was implemented and results obtained were compared with experimental data in order to check possibility of use of appropriate software for the reproduction of real conditions of fires at residential buildings.
Speech spectrum analyses for estimating operator functionality
Authors: Korsun O N , Yurko V N , Beyseev S A , Naukenova A S , Tulekbaeva A K 
Published: January 2021

Abstract
The paper deals with the problem of estimating human operator functional characteristics using frequency analysis of operator’s speech. The analysis is carried out using operator’s speech transfer function based on the classical definition of transfer function in the automatic control theory. The algorithms for calculating the operator’s speech transfer function are presented, the experimental results are discussed.
To the question of calculating the run distance of the lightweight WIG plan at the stage of preliminary design
Authors: Luchkov A N 
Published: January 2021

Abstract
The work is devoted to the study of the take-off characteristics of high-speed vessels of the WIG type. On the basis of the conducted research, a method for calculating the range of range was developed, considering different types of launch devices during take-off from the water surface. The development of such a method is conditioned by the presence in the design of WIG plans of the problem of determining the most advantageous starting device at takeoff from water under given operating conditions. The proposed method is based on the law of momentum conservation. The method takes into account aerodynamic, hydrodynamic characteristics of WIG plans, characteristics of the power plant from the ship’s speed. According to the results of this method it is possible to make a decision on the choice of the most advantageous starting device, providing the performance of the technical task at the stage of preliminary or conceptual design of the ekranoplan. Verification of the technique was carried out using data obtained at the stage of running tests of Orion-10 and Orion-20 WIG plans. The satisfactory coincidence of calculation results and experimental data was obtained.
Production expert system to determine aircraft take-off and landing performance
Authors: Melnichuk A V , Nesterov V A , Sudakov V A , Sypalo K I 
Published: January 2021

Abstract
This paper deals with the design of automated system for take-off and landing performance computing which is applicable to a wide range of aircrafts. The designed solution uses expert systems technology based on rules. The algorithm for logical inference of the expert system is developed.
Criterion and principles of easily-modified program
Authors: Prutzkow A 
Published: January 2021

Abstract
Ease of modifying is one of the characteristics of the program. The existing approaches do not clarify this concept. These approaches are clean code and maintainability. We formulate simple and explicit criterion and principles of easily-modified programs. The criterion is an E.W. Dijkstra’s criterion. The principles are (1) the names of the elements should reflect their purpose in the program; (2) use indentation for nested statements and blank lines; (3) one program element must have one assignment and one assignment must correspond to only one element; (4) optimize dependencies between program elements. We introduce a metric for easily-modified programs as well. It’s a number of commands in methods and static blocks in a class.
Dissimilar heat transfer enhancement by introduction of a vortex tube in plane Couette flow
Authors: Kubo A , Kawahara G , Shimizu M 
Published: January 2021

Abstract
Recent studies have suggested that a cyclonic vortex, which has the same signed vorticity as that of background shear, can lead to dissimilar heat transfer enhancement, i.e. more heat transfer than momentum transfer. However, it has not yet been known how the cyclonic vortex achieves dissimilarity, or if other types of vortices would also lead to dissimilarity. In order to tackle these problems, we introduce a straight vortex tube into laminar plane Couette flow under various conditions and numerically investigate heat and momentum transfer therein. The essential process for dissimilarity is isolated from complex ingredients of realistic flow to consider the interaction of a vortex with background shear. It is found that introduction of a strong spanwise anti-cyclonic vortex, which has the opposite signed vorticity to that of background shear, can realize more dissimilar heat transfer than the known cyclonic vortex as a consequence of the long-term interaction with the background flow, whereas the spanwise cyclonic vortex achieves larger dissimilarity in the early stage of its time evolution. The physical mechanisms of dissimilarity due to these vortices are elucidated by interpreting the distribution of the streamwise pressure gradient and the resulting difference between temperature and streamwise velocity around the vortex.
Investigation of the influence of graded-gap layer formed by annealing on the electrical properties of the near-surface of LPE HgCdTe using MIS structure
Authors: Lu Qi , Wang Xi , Wei Yanfeng , Sun Quanzhi , Lin Chun 
Published: January 2021

Abstract
The influence of the near-surface graded-gap layer formed by annealing of HgCdTe grown by liquid phase epitaxy on the capacitance-voltage characteristics of its MIS structure was studied. We found that HgCdTe grown by LPE can form a near-surface graded-gap layer by annealing under specific conditions after CdTe passivation. After the near-surface graded-layer is generated, the performance of the HgCdTe surface layer has been changed significantly, showing as an increase of slow states, a decrease of fixed charge and the generation of single-level trap in the band gap. Furthermore, a Fermi level pinning phenomenon have been observed on the HgCdTe with graded-gap layer, highlighting the huge density of interface traps at the edge of the band. This effect may be attributed to the electric field generated by the graded-gap layer in HgCdTe driving minority carriers away from the interface. As a result, the surface recombination velocity of minority carriers is reduced. At the same time, it inhibits the oxidation reaction on the surface and consequently reduces the accumulation of fixed charges. During the annealing process to form the graded-layer, the defect system on the surface is reorganized, and the defect aggregation produces single-level defects and higher electron traps.
Ag-containing aluminum-silicon alloys as an alternative for as-cast components of electric vehicles
Authors: Gomes Leonardo Fernandes , Silva Bismarck Luiz , Silva Jr Paulo Sérgio da , Garcia Amauri , Spinelli José Eduardo 
Published: January 2021

Abstract
The development of new light and efficient systems in electric vehicles (EV) opens up new research opportunities. One of these fronts involves the development of alternative Al-Si alloys. With the current demands for increased EV autonomy, alloys that are more conductive yet strong enough should be developed. Within this context, the present research work evaluates the addition of Ag (0.1 and 2.0 contents) in the high silicon Al-10 wt.% Si alloy. This Si content is due to the typical content of cast alloys normally used in EV components. Several samples with different dendritic scales were solidified. After, their microstructures, electrical conductivity and tensile properties have been evaluated. It is demonstrated that samples of the Al-10 wt.% Si-0.1 wt.% Ag alloy corresponding to λ
2 of 30 μm allow tensile properties of: 160 MPa of strength, 12% of ductility and electrical conductivity of 34% IACS. These properties show promise for adding Ag to new EV alloys.
Adsorption of SO2 on pristine and defective single-walled MgO nanotubes: a dispersion-corrected density-functional theory (DFT-D) study
Authors: Wang Mengxin , Chen Yingrui , Wang Wenju , Zhang Teng 
Published: January 2021

Abstract
The dispersion-corrected density functional theory (DFT-D) has been used to study the interactions of SO2 on the pristine and defective single-walled MgO nanotubes (MgONTs). A geometric optimization was performed for MgONTs and adsorbents/MgONTs. The adsorption energies of SO2 molecules at different layers of MgONTs were considered. The adsorption property of SO2 was analyzed in terms of the adsorption energy, the electron donation (basicity), and the atomic charges on the adsorbed materials. The densities of states (DOS) have been calculated and used for examining the adsorption properties. In addition, the presence of vacancy defects increases the adsorption energies of the SO2molecules. The band gaps of the defective MgONTs are sensitive to SO2 molecules.
Mechanical and tribological performance of Al-Fe-SiC-Zr hybrid composites produced through powder metallurgy process
Authors: Raghav G R , Janardhanan Sheeja , Sajith E , Chandran Vidya , Sruthi V 
Published: January 2021

Abstract
In this work a ternary Al-Fe-SiC metal matrix composites were reinforced using Zr particles through powder metallurgy process. The Al matrix and the reinforcements were mixed in high energy ball mill at a speed of 250 rpm over a period of 5 h so as to develop a homogenously dispersed composite material. The composite powders are then pressed at 500 MPa using hydraulic press. The compressed composite green compacts are then sintered at 500 °C for 2 h and allowed to cool under furnace atmosphere. The densities, micro hardness and compressive strength of Al-Fe-SiC-Zr composites were investigated and reported. The composite materials were characterized using SEM, EDS and XRD. The density of Al-10Fe-10SiC-10Zr hybrid composites was found to be around 3.44 g cm−3. The Zr particles have influenced the micro hardness of the composite materials. The micro hardness of the Al-10Fe-10SiC-10Zr hybrid composites was found to be better compared to Al-10Fe and Al-10Fe-10SiC hybrid composites. The compressive strength of the Al-10Fe-10SiC-10Zr hybrid composites was around 205 MPa which is 44% higher than the Al-10Fe composite material. The porosity of the hybrid composites has reduced when compared to that of Al-10Fe and Al-10Fe-10SiC hybrid composites. The wear studies reveal that Al-10Fe-10SiC-10Zr bear out better wear resistance. The predominant wear mechanism was identified as adhesive wear followed by plastic deformation. This improved wear resistance was due to the formation of oxides layers such Al2O3, Fe2O3 and also due to the presence of AlFe3 and Al3Zr4 intermetallics.
Orbital angular momentum of twisted light: chirality and optical activity
Authors: Forbes Kayn A , Andrews David L 
Published: January 2021

Abstract
Optical activity is conventionally understood as a natural difference in the optical responses of chiral materials with opposite handedness. It stems from the quantised spin angular momentum ±ħ per photon, with the ± representing either left- or right-handed circular polarisations. Less well known, until recently, was the possibility that matter might also respond in a similar, discriminatory way to the handedness of twisted light, or ‘optical vortices’, whose orbital angular momentum (OAM) is quantised as

ℓ
ℏ

per photon, where

ℓ

is the topological charge whose sign determines a wavefront twist to the left or right. Initial studies focusing on whether, in spectroscopic applications, chiral matter might respond differently to the vortex handedness of

+
ℓ

and

−
ℓ

beams, failed to identify any viable mechanism. However, in the last few years, theory and experiment have both supplied ample evidence that, under certain conditions, such forms of interaction do exist—and as a result, the field of chirality and optical OAM is beginning to flourish at a pace. This topical review presents a survey of this new field, working up from a description of those initial studies to the cutting-edge experiments now taking place. Analysing the fundamental mechanisms provides for a revision of previous precepts, broadening their scope in the light of recent advances in understanding, and highlighting a vibrant synergy between the fields of optical activity and twisted light.
2021 roadmap on lithium sulfur batteries
Authors: Robinson James B , Xi Kai , Kumar R Vasant , Ferrari Andrea C , Au Heather , Titirici Maria-Magdalena , Parra-Puerto Andres , Kucernak Anthony , Fitch Samuel D S , Garcia-Araez Nuria , Brown Zachary L , Pasta Mauro , Furness Liam , Kibler Alexander J , Walsh Darren A , Johnson Lee R , Holc Conrad , Newton Graham N , Champness Neil R , Markoulidis Foivos , Crean Carol , Slade Robert C T , Andritsos Eleftherios I , Cai Qiong , Babar Shumaila , Zhang Teng , Lekakou Constantina , Kulkarni Nivedita , Rettie Alexander J E , Jervis Rhodri , Cornish Michael , Marinescu Monica , Offer Gregory , Li Zhuangnan , Bird Liam , Grey Clare P , Chhowalla Manish , Lecce Daniele Di , Owen Rhodri E , Miller Thomas S , Brett Dan J L , Liatard Sebastien , Ainsworth David , Shearing Paul R 
Published: January 2021

Abstract
Batteries that extend performance beyond the intrinsic limits of Li-ion batteries are among the most important developments required to continue the revolution promised by electrochemical devices. Of these next-generation batteries, lithium sulfur (Li–S) chemistry is among the most commercially mature, with cells offering a substantial increase in gravimetric energy density, reduced costs and improved safety prospects. However, there remain outstanding issues to advance the commercial prospects of the technology and benefit from the economies of scale felt by Li-ion cells, including improving both the rate performance and longevity of cells. To address these challenges, the Faraday Institution, the UK’s independent institute for electrochemical energy storage science and technology, launched the Lithium Sulfur Technology Accelerator (LiSTAR) programme in October 2019. This Roadmap, authored by researchers and partners of the LiSTAR programme, is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the LiSTAR consortium. In compiling this Roadmap we hope to aid the development of the wider Li–S research community, providing a guide for academia, industry, government and funding agencies in this important and rapidly developing research space.
Transition to synchrony in chiral active particles
Authors: Pikovsky Arkady 
Published: January 2021

Abstract
I study deterministic dynamics of chiral active particles in two dimensions. Particles are considered as discs interacting with elastic repulsive forces. An ensemble of particles, started from random initial conditions, demonstrates chaotic collisions resulting in their normal diffusion. This chaos is transient, as rather abruptly a synchronous collisionless state establishes. The life time of chaos grows exponentially with the number of particles. External forcing (periodic or chaotic) is shown to facilitate the synchronization transition.
Data-driven enhancement of cubic phase stability in mixed-cation perovskites
Authors: Park Heesoo , Ali Adnan , Mall Raghvendra , Bensmail Halima , Sanvito Stefano , El-Mellouhi Fedwa 
Published: January 2021

Abstract
Mixing cations has been a successful strategy in perovskite synthesis by solution-processing, delivering improvements in the thermodynamic stability as well as in the lattice parameter control. Unfortunately, the relation between a given cation mixture and the associated structural deformation is not well-established, a fact that hinders an adequate identification of the optimum chemical compositions. Such difficulty arises since local distortion and microscopic disorder influence structural stability and also determine phase segregation. Hence, the search for an optimum composition is currently based on experimental trial and error, a tedious and high-cost process. Here, we report on a machine-learning-reinforced cubic-phase-perovskite stability predictor that has been constructed over an extensive dataset of first-principles calculations. Such a predictor allows us to determine the cubic phase stability at a given cation mixture regardless of the various cations’ pair and concentration, even assessing very dilute concentrations, a notoriously challenging task for first-principles calculations. In particular, we construct machine learning models, predicting multiple target quantities such as the enthalpy of mixing and various octahedral distortions. It is then the combination of these targets that guide the laboratory synthesis. Our theoretical analysis is also validated by the experimental synthesis and characterization of methylammonium–dimethylammonium-mixed perovskite thin films, demonstrating the ability of the stability predictor to drive the chemical design of this class of materials.
Combined depth-resolved cathodoluminescence spectroscopy and transmission electron microscopy on Al(Ga)N multi quantum well structures
Authors: Hocker Matthias , Thonke Klaus , Li Yueliang , Biskupek Johannes , Kaiser Ute , Scholz Jan-Patrick , Hubáček Tomáš , Rettig Oliver , Scholz Ferdinand 
Published: January 2021

Abstract
A stack of five Al(Ga)N-based quantum wells is investigated by combined laterally and depth resolved cathodoluminescence (CL) spectroscopy in order to distinguish lateral and vertical inhomogeneities of these wells. Transmission electron microscopy (TEM) micrographs provide data for the real sample structure, which enters into the Monte-Carlo simulation of the depth-resolved CL measurements to refine the depth resolution. The comparison of these CL measurements to the results of electron energy loss spectra (EELS) allows to identify local thickness variations of the lower three quantum wells to be the origin of two different luminescence contributions to the overall spectrum. The differentiation of the two groups of quantum wells by depth-resolved CL is demonstrated.