bluuebunny/crossref_metadata_2025_split huggingface dataset:
National round robin test (RRT) for delamination strength testing YBCO HTS wires at room temperature (RT) and 77K
Authors: Liu Chuanguang , Shi Yunfan , Liu Cong , Tao Shu , Liu Fang , Chen Sikan , Xia Huineng , Zhou Jun , Zhang Xing-Yi 
Published: July 2023

Abstract
Second generation high temperature superconducting coated conductors (2G HTS CCs) have become indispensable wires for high-field superconducting magnets. The transverse mechanical delamination strength (MDS) is a key parameter due to the multilayer structure of CCs. Determination of the MDS value is thus significant. In this study, we report the MDS results of national round robin test (RRT) conducted in china by the institutions of Lanzhou University, Institute of Plasma Physic, and Shanghai Superconductor Technology Co., Ltd at room temperature (RT) and 77 K, respectively, for the determination of 2G HTS CCs (copper-stabilized) transverse MDS by a standardized procedure. Data at RT and 77 K all showed good consistency, with the relative standard uncertainty of 2.22% and 2.35%, respectively, illustrating the reliability of the established procedure, which can be used as a reference for engineering CC manufacturing and design of application magnets.
Improving the accuracy of a weighing scale by rigorously combining measurements
Authors: Boguslawski M , Mirbach B 
Published: July 2023

Abstract
In this paper, we investigate the question of how much measurement accuracy of additive quantities can be increased by the method of combined measurements. Therefore, we consider measurements of all possible combinations of n labeled masses and then estimate the individual weights of the n masses by a linear regression approach. We present experimental results which motivate comprehensive simulation campaigns. These simulations provide valid statistical statements and reliable forecasts of the experimental results. A profound analytical treatment, in turn, supports these simulation outcomes with excellent consistency. One important achievement therein is a general analytical expression for the accuracy that can be achieved by combined measurements. It turns out this method allows to estimate the weight of mass elements with an accuracy that potentially under-runs by orders of magnitude the resolution of the scale used. In a broader sense, our work wants to promote the method and give inspirations to applications in various metrological fields beyond high-precision mass determination.
Lyapunov exponents and phase transitions of Born-Infeld AdS black holes
Authors: Yang Shaojie , Tao Jun , Mu Benrong , He Aoyun 
Published: July 2023

Abstract
In this paper, we characterize the phase transitons of Born-Infeld AdS black holes in terms of Lyapunov exponents. We calculate the Lyapunov exponents for timelike geodesics in background metric and photon geodesics in effective metric. It is found that black hole phase transitions can be described by multiple-valued Lyapunov exponents. And its phase diagram can be characterized by Lyapunov exponents and Hawking temperature. Besides, the change of Lyapunov exponents can be considered as order parameter, and exists a critical exponent 1/2 near critical point.
Constraining the spatial curvature with cosmic expansion history in a cosmological model with a non-standard sound horizon
Authors: Stevens Jordan , Khoraminezhad Hasti , Saito Shun 
Published: July 2023

AbstractSpatial curvature is one of the most fundamental parameters in our current concordance flat ΛCDM model of the Universe. The goal of this work is to investigate how the constraint on the spatial curvature is affected by an assumption on the sound horizon scale. The sound horizon is an essential quantity to use the standard ruler from the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAOs). As an example, we study the curvature constraint in an axion-like Early Dark Energy (EDE) model in light of recent cosmological datasets from Planck, the South Pole Telescope (SPT), and the Atacama Cosmology Telescope (ACT), as well as BAO data compiled in Sloan Digital Sky Survey Data Release 16. We find that, independent of the CMB datasets, the EDE model parameters are constrained only by the CMB power spectra as precisely and consistently as the flat case in previous work, even with the spatial curvature. We also demonstrate that combining CMB with BAO is extremely powerful to constrain the curvature parameter even with a reduction of the sound-horizon scale in an EDE model, resulting in ΩK= -0.0058± 0.0031 in the case of ACT+BAO after marginalizing over the parameters of the EDE model. This constraint is as competitive as the Planck+BAO result in a ΛCDM model, ΩK= -0.0001± 0.0018.
Coherent states of the free quantum particle in a viscous medium
Authors: Sazonov S V 
Published: July 2023

Abstract
On the basis of the canonical quantization procedure, the motion of a micro-particle in a viscous medium is considered, where the drag force consists of two components proportional to the first and second degrees of velocity, respectively. The wave function of a particle corresponding to its quantum coherent state is found using the quasi-classical approach. It is shown that due to the viscous of the medium, a static localized domain of the probability density is formed at relatively long times. It is shown that the parameters of this domain contain the information about the parameters of the particle on the input to medium.
Continuous synthesis of artificial speech sounds from human cortical surface recordings during silent speech production
Authors: Meng Kevin , Goodarzy Farhad , Kim EuiYoung , Park Ye Jin , Kim June Sic , Cook Mark J , Chung Chun Kee , Grayden David B 
Published: July 2023

Abstract

Objective. Brain–computer interfaces can restore various forms of communication in paralyzed patients who have lost their ability to articulate intelligible speech. This study aimed to demonstrate the feasibility of closed-loop synthesis of artificial speech sounds from human cortical surface recordings during silent speech production. Approach. Ten participants with intractable epilepsy were temporarily implanted with intracranial electrode arrays over cortical surfaces. A decoding model that predicted audible outputs directly from patient-specific neural feature inputs was trained during overt word reading and immediately tested with overt, mimed and imagined word reading. Predicted outputs were later assessed objectively against corresponding voice recordings and subjectively through human perceptual judgments. Main results. Artificial speech sounds were successfully synthesized during overt and mimed utterances by two participants with some coverage of the precentral gyrus. About a third of these sounds were correctly identified by naïve listeners in two-alternative forced-choice tasks. A similar outcome could not be achieved during imagined utterances by any of the participants. However, neural feature contribution analyses suggested the presence of exploitable activation patterns during imagined speech in the postcentral gyrus and the superior temporal gyrus. In future work, a more comprehensive coverage of cortical surfaces, including posterior parts of the middle frontal gyrus and the inferior frontal gyrus, could improve synthesis performance during imagined speech. Significance. As the field of speech neuroprostheses is rapidly moving toward clinical trials, this study addressed important considerations about task instructions and brain coverage when conducting research on silent speech with non-target participants.
Magneto-optical properties of water and saltwater in presence of a magnetic field
Authors: Dhobi S H , Nakarmi J J , Waiba R , Koirala B , Yadav K , Gupta S P , Das S K , Shah A K , Paudel K , Dahal K , Sah R L , Lemle L D 
Published: July 2023

Abstract
The magneto-optical (transmittance, absorbance, and reflectance) characteristics of water and saltwater in the presence of a magnetic field (0T to 0.880T) are investigated in this study. The authors studies Raman spectra shift and a magneto-optical response of water and saltwater in magnetic fields. In the case of water, the transmittance is high in a high magnetic field, but in the case of saltwater, the transmittance is low at the low wavelength of the spectrum. The transmittance of water was found to be 0.7 percent higher in the presence of a high magnetic field of 0.88T than in the absence of a magnetic field at the wavelength of 651nm–655.67nm. Similarly, under the same magnetic field (0.88T), transmittance of seawater was found to be 0.9 percent higher at 401.44nm and absorbance was found to be 3.4 percent higher at 622.72nm and 646nm. High magnetic fields, on the other hand, have higher absorbance and reflectance in saltwater than 0.222T and 0T. The MO response was found to be larger in water at 0.880T than in saltwater at 0.222T. At 0.880T, the maximal MO response of water and saltwater is reported to be 0.004983 and 0.009804, respectively, at wavelengths of 668.2 nm and 400 nm. When compared to 0T, the intensity ratio of water is deflected more in a high magnetic field than in a low magnetic field, whereas the intensity ratio of saltwater is deflected less in a high magnetic field than in non-magnetic and low magnetic fields.
Optimizing the operation of photovoltaic panels using mathematical regression models
Authors: Rat C L , Ichim-Burlacu C , Bistrian D A 
Published: July 2023

Abstract
Solar (PV) panel models are necessary for the implementation of solar panel control algorithms such as maximum power point tracking. If real-time control is required, these models will be used on microcontrollers and, therefore, will be subject to constraints of memory and execution time: the model implemented on the microcontroller must occupy a memory area as small as possible and the mathematical relationships it contains can be computed in the shortest possible time. Analytical models usually do not fit this criteria, therefore searching for equivalent models which do fit it is required. In this paper, equivalent mathematical models are determined in the MATLAB programming environment based on data obtained by simulating an analytical model in the LabVIEW programming environment. In this paper, the models were obtained by modeling the current distribution in the panel through regression methods, more specifically by using an optimal response surface which has been validated through the resolution of an optimization problem with restrictions. The optimal response surface was used to estimate the extreme values of the power produced by the panel for certain given weather conditions (maximum power in summer and minimum power in winter).
Control algorithm of the unstable 3DOF system
Authors: Erceg D , Grahovac Z , Knezevic B Z 
Published: July 2023

Abstract
The basic characteristics of a system with three degrees of freedom (3DOF) are nonlinearity and instability. An example of such a system is a double pendulum inverted on a moving platform, that is, a pendulum system with two joints and two rods. These characteristics make the system a perfect model for testing various control algorithms such as PID controllers, linear quadrature optimization (LQR) controllers, neural networks, fuzzy logic, etc. This paper presents the mathematical modeling and method for control of the 3DOF system by applying only the force acting on the platform. The system is modeled using Lagrange equations of the second type, which are used as a systematic method for obtaining differential equations of motion systems. To be able to apply the basic concept of control, it is necessary to linearize the system. Differential equations are solved numerically by applying the Runge - Kutta method ode45. A linear quadrature optimization (LQR) controller was used as the controller. The simulation and the results of the proposed control method are verified by computer simulations. This paper presents the difference between a linearized and a non-linearized system. The advantage of the proposed control concept is reflected in the fact that with very small changes it can be extended to the control of many other nonlinear systems.
Analysis of the problems of acquisition of digital photographs intended to determine the required dimensional accuracy of the product
Authors: Turinski D , Svalina I , Šarić T , Lujić R , Havrlišan S 
Published: July 2023

Abstract
In this paper, some of the problems arising from the acquisition of digital photography intended to determine the dimensional accuracy of products are discussed. Different equipment (digital cameras, lenses, and lighting) was used when acquiring photos in different formats. In mechanical engineering, the tolerances of dimensional measurements of products range from a few microns to 100 microns. Based on that, the technical specifications and capabilities of the cameras and lenses used are analyzed. In addition to the sensor, the resolution of the photo is often limited by the lens. Prior to the acquisition of photographs, problems such as lighting, contrast, sharpness, and the problem of central projection are addressed. During acquisition, technical specifications of the lens such as focal length, minimum focusing distance, aperture, and other lens features that cause acquisition problems are considered. This research and analysis led to valuable insights and conclusions that will facilitate the preparation of the acquisition of digital photography to determine the dimensional accuracy of the product.
The case study of new approach to robot programming and layout design by supporting virtual and augmented reality
Authors: Holubek R , Kusá M , Bocák R 
Published: July 2023

Abstract
In currently designed robotic systems, great emphasis is focused to optimal choice of the appropriate position (smart place) of a particular type of industrial robot. Depending on the chosen application, whether it is a handling, technological or assembly operation, it is very important to choose a suitable type of robot and end effector. Many problems in actually deployed production systems arise from the inappropriately chosen kinematic structure of an industrial robot, where either the robot cannot achieve the required production cycle, or its size or load capacity is incorrectly selected for a given type of the operation, or in some cases the robot does not achieve all required robot targets of the future robotic workplace. In the currently available methods of designing future robotic systems, the pre-production phase of designing and creating various robotic simulations scenarios a very important role in order to verify the robot’s reachability to the required positions, as well as eliminate possible collisions states with different peripherals, etc.. This article aims to point out to the new possibilities of deploying modern technologies in the form of the use of virtual and augmented reality in the chosen case study. The authors aim to show and verify in the VR and AR environment the suitability of the selected type of industrial robot for the selected operation, to simulate and validate the proposed robotic trajectories as well as the final robotic Pick and Place operation for the selected case study.
Management of experimental data resulting from the investigation of applications implemented through SAP UI technologies
Authors: Berdie A D , Rob R S , Raţ C L , Berdie A A , Păun A 
Published: July 2023

Abstract
The process of managing data from measurements involves a set of methods and algorithms to explore and analyze them in order to determine specific structures that reproduce as accurately as possible the essence of the information resulting from them. This paper focuses on the statistical processing and interpretation of measurement data sets derived from measurements in web applications using three SAP UI technologies: Web Dynpro ABAP, Floorplan Manager, and CRM WebClient UI. Aspects related to determining the main statistical parameters, eliminating the values affected by gross errors, checking the randomness of the data, determining the distribution functions corresponding to each data sample, and checking the distributions based on concordance tests are considered.
Topological optimization of vice jaws model for pipe clamping
Authors: Mumović M , Šibalić N , Vujović A , Jovanović J 
Published: July 2023

Abstract
This paper presents a model of the clamping vice jaw that is being developed for clamping the aluminium pipes. This model will be used on an available power hack for cutting the pipes to the desired length for further processing. In order to increase the stiffness to weight ratio of a given model, and thus optimize the material usage, the Topology Optimization method is implemented. The geometry of the jaw needs to adjust to the shape of the pipe, so it does not deform it when the clamping force is applied, and also be made from a material softer than aluminium, so that it does not damage the surface of the pipe. These conditions make the jaws a good candidate to manufacture by FDM 3D printing technology, from frequently used ABS material. As this process is a method of Additive Manufacturing, Topology Optimization benefits it not only in material usage but also in production time and cost. The presented procedure has a general character and as such can be applied to many mechanical parts, especially those made by Additive Manufacturing technologies.
Technical and ecological characteristics of utilizing the hydroelectric power potential of HPS “Gornja Drina” in Republic of Srpska
Authors: Kasikovic O , Dobrnjac N , Dobrnjac M , Golubovic D 
Published: July 2023

Abstract
Water has been extensively used as a renewable energy source. Many countries around the globe generally satisfy their demand for energy from precisely this energy source. In many countries of the world, the production of electricity is increasingly being created by hydropower capacities. Global demands for electricity are looking forward to being satisfied mostly from renewable energy sources, especially when it comes to hydropower. This paper presents the planned production of electricity in Republic of Srpska in 2022. The technical characteristics of HPS “Gornja Drina” are also considered, as well as the possible environmental impacts that would occur with the construction of new hydropower plants.
Increasing the fatigue strength of threaded joints of oil and gas equipment by plastic deformation of the thread under high load before make-up
Authors: Kopei V B , Onysko O R , Panchuk V G , Odosii Z M , Kusyi Y M 
Published: July 2023

Abstract
Uneven distribution of stresses in the thread can cause fatigue failure of the joint, usually in the area of the first roots of the thread. This problem is very relevant for shouldered threaded joints of oil and gas equipment, which operate under conditions of significant cyclic loads. One of the ways to equalize the stresses in the thread is plastic deformation of the thread with a high load before make-up. The influence of various methods of such pre-deformation of the tool joint of drill pipes and the connection of sucker rods on the fatigue life in the thread roots of the pin and box has been studied. A method for optimizing the load for pre-deformation was proposed and it was found that the optimal load can increase the fatigue life by 5 times. The study was carried out by finite element analysis of the axisymmetric model in Abaqus/CAE and calculation of the fatigue life from the Brown-Miller dependence using fe-safe.
Cavitation behavior study of the aging heat treated aluminum alloy 7075
Authors: Luca A N , Bordeasu I , Ghiban B , Demian A M , Ghera C 
Published: July 2023

Abstract
Aluminium-based alloy type 7075 is known for its good ductility, high mechanical strength, toughness and high fatigue strength, which is why it is mainly used in the construction of dynamically stressed parts in the structure of airplanes, vehicles and ships. Although it has these qualities, at present its behavior has not been studied at the hydrodynamic stresses that allow it to be used in parts that work in cavitation conditions, such as pump rotors and boat propeller blades. Therefore, the research in this paper highlights the behavior of laminated semi-finished structures and obtained by heat treatment of artificial aging at 180°C, with a maintenance time of one hour. Of the 7075 alloy at the demands generated by the vibrating cavity, created by the standard vibrating device with piezoceramic crystals (frequency of 20 kHz, amplitude of 50 µm and electrical power of 500 W). Analysis based on the curves MDE (t) and MDER (t), of the specific parameters of cavitation erosion MDEmax and MDERs as well as of the macro and microscopic images of the eroded structures of cavitation show that, compared to the delivered state (semi-finished), by the heat treatment applied the microstructure does not change cavitation
Improvement of mechanical properties of bevel gears by nitrocarburizing
Authors: Mihuţ G , Ardelean M 
Published: July 2023

Abstract
The automotive industry is one of the most important consumers of materials and especially metal materials. Competition in this area, technical progress and vehicle requirements require knowledge of the properties of materials, processing technologies that ensure operating requirements, reliability, and aesthetic requirements, with minimum costs.
This work is part of modern trends to improve the surface layers of parts used mainly in the automotive industry and beyond. A nitrocarburizing study is presented on the tapered gears that make up the machine differential, as well as the optimization of the nitrocarburizing technology.
The paper describes the objectives of nitrocarburizing, the materials used for this purpose, ending with the structures and properties obtained after nitrocarburizing.
Deflection Compensation Analysis of a 3-RRS Parallel Mechanism
Authors: Li Lanbin , Chen Qiusheng , Wang Manxin 
Published: July 2023

Abstract
Parallel mechanisms have the advantage of high rigidity, large payload capability, and so on, but the positioning accuracy is affected by the elastic deflection arising from external load and gravity. An approach to improving accuracy by compensating elastic deflection is presented with a 3-RRS parallel mechanism as the research object. The approach is implemented by introducing springs on the moving platform and the limbs. Taking the external load, spring force, and gravity, the mechanical and deflection models are established, which can effectively separate the influence of spring force and gravity on the deflection at the endpoint. In addition, considering the constraints of the mechanism’s operating capacity, the springs’ layout and parameters optimization design are studied based on the compensation effect of springs on the global deflection of the platform. The example shows that the method can effectively compensate for the deflection, and the spring applied on the moving platform has the best compensation effect, which can compensate for 91% of the deflection.
Additive Manufacturing of Silicon Oxycarbide Ceramics with Minimal Surface Structures
Authors: Li Jinghan , Shi Yu , Cao Lei , Zhang Zhuoqing , Zhang Xing 
Published: July 2023

Abstract
The traditional ceramic powder sintering forming method severely limits the performance of the fabricated parts. Many new solutions have been achieved by precursor derived ceramics (PDC). Silicon oxycarbide ceramics as one of them has many performance advantages such as excellent mechanical properties, low density, excellent thermal stability, low thermal conductivity, and resistance to thermal shock and corrosion. In this paper, a photosensitive polysiloxane resin (PPR) with excellent light curing properties was prepared, which has high precision in the process of additive manufacturing. In addition, samples with minimal surface features in different porosity were fabricated. The compressive strength of the structure with 85%, 75%, and 65% porosity was about 9.51 MPa, 13.76 MPa, and 21.69 MPa, respectively. These porous silicon oxycarbide ceramics are likely to have a wide range of potential applications in aerospace, aviation, and other fields.