bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensorless control of submersible permanent magnet synchronous motor under long-line cable model
Authors: Yue Youjun , Zheng Lihua 
Published: February 2024

Abstract
In the process of oil production, the submerged oil motor works 1-3 km downhole and is connected to the inverter by a long-wire cable, which generates overvoltage at the motor end due to the problem of matching the impedance of the motor with the impedance of the power cable. The downhole environment is not suitable for the installation of precision devices, such as position sensors. To solve these problems, a sensorless control method of submerged oil motors based on a high-frequency voltage injection method is proposed. A motor terminal voltage and current observer under a long-wire cable model is designed to estimate the actual values of motor terminal voltage and current by collecting the voltage and current at the inverter terminal. A three-level inverter is used to provide energy to the submersible oil electric pump through the long-wire cable, which can effectively suppress the motor terminal overvoltage compared to the two-level inverter. The control algorithm is verified by modeling the whole system using simulation software.
Control Method for Inhibiting Chain Reaction of Commutation Failure
Authors: Ouyang Jinxin , Pang Mingyu , Pan Xinyu , Lei Xiao , Li Baowei 
Published: February 2024

Abstract
Due to the coupling effect between the DC/AC system as well as between different LCC-HVDC, the first commutation failure can cause a series of chain reactions, including successive commutation failure, overvoltage of the rectifier station, and subsequent commutation failure. The existing control methods for suppressing overvoltage or commutation failure cannot simultaneously meet the needs of the sending and receiving end grid of MIDC. It may expand the impact and scope of a single fault. Therefore, a commutation failure chain reaction suppression method is proposed based on the characterization of chain reaction boundary conditions. The effectiveness is verified by using the CIGRE standard test model.
Research on Multi-point Measurement System of Mine Gas Based on TDLA
Authors: Liu Yahui , Liu Xu , Zhang Sheng , Zhang Yuxi , Yin Chuanye 
Published: February 2024

Abstract
Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology combines the advantages of wavelength modulation technology and direct absorption spectroscopy technology, and the system achieves highly sensitive and full-range detection of methane gas concentrations. In the system, only the pure optical methane probe is positioned under the mine, which establishes connectivity with the host computer on the surface through the optical fiber. This setup enables the simultaneous detection of 16 channels of methane gas through time-sharing multiplexing technology. Experimental results demonstrate a measurement error of less than ±6.0×10−4 at low concentrations (0∼1%) and within ±6% of the true value at high concentrations under normal temperature and pressure conditions. The full-range linear fit attains 0.9998. According to the one-fold standard deviation, the minimum detection lower limit of the system stands at 68.36 ppm and the measured gas concentrations across different channels of the methane probes remain consistent inhe same environment. This technology provides a new solution for continuous, accurate, and multi-point monitoring of mine gas.
Design of human lower limb motion data acquisition system based on multi-sensor
Authors: Pang Peng , Shi Yunling , Liu Gang , Tang Leilei 
Published: February 2024

Abstract
In order to protect the health of older people, a wearable lower extremity motion data acquisition system was designed. With STM32F103C8T6 as the core, the system uses an inertial attitude sensor to collect lower limb motion attitude information. In view of the large difference in plantar pressure data of different fall types, the distributed flexible film plantar pressure sensor is used to collect plantar pressure information as an auxiliary discrimination means, which can accurately distinguish the fall behavior from other behaviors, and carry out data transmission through the wireless module. The device is small in size, light in weight, low in power consumption, and wearable, which is easy to apply in the field of health monitoring, and can also be used as a reference for the implementation of corresponding protection strategies for active lower limb prosthetics.
Observer based fault diagnosis of aircraft active landing gear system
Authors: Sun Zhongzhou , Wu Zheng , Li Fanbiao 
Published: February 2024

Abstract
A landing gear system is vital in aircraft landing and taxiing. In this paper, an observer-based fault detection and fault reconstruction means is adopted for the aircraft’s active landing gear. Firstly, a six-degree-of-freedom (6-DOF) landing gear model is established by analysing the dynamics of the fuselage and landing gears. By analysing the fault mechanism of actuators and sensors, the fault model of actuators and sensors is established. Secondly, according to the above model, the unknown input observer (UIO) is designed to obtain the residuals, and the fault detection of actuators and sensors is realized according to the comparison between residuals and thresholds. On this basis, an adaptive unknown input observer (AUIO) is designed, through which the state values and fault values can be reconstructed. Finally, simulation experiments are tested under different fault types to prove the validity of the fault detection and reconstruction based on UIO and AUIO.
Research on vision control methods based on multi-sensor fusion
Authors: Wang Yi , Qu Fengrui , Wang Xijun , Zeng Songtao , Sun Qizhen , Li Mengyang , Ge Jiafei 
Published: February 2024

Abstract
This paper focuses on the application scenarios of electric power live line working robots, addressing tasks such as live wire stripping and live wire connection/disconnection. It utilizes Mixed Reality (MR) technology for rapid environment modeling and visual signal acquisition. Through the research on robot contact force sensing, real-time force feedback, and obstacle avoidance through the fusion of robot motion paths and environmental data, it establishes a novel electric power live line working robot system centered around dexterous dual arms at the operation end, force feedback teleoperation controllers, multi-sensor fusion acquisition systems, and robot motion planning and control technology. Through prototyping, a demonstration application is realized, showcasing a semi-autonomous electric power live line working robot system that employs remote operation combined with sensor-based MR for task execution. This teleoperation and Mixed Reality-based semi-autonomous electrified operation approach is poised to play a significant role in advancing and demonstrating the use of robots in the field of electrical grid operations.
Simulation study on firing parameters optimization of parallel salvo of active acoustic homing torpedo
Authors: Xu Zhaopeng , Zhang Yan , Cheng Fei 
Published: February 2024

Abstract
In the process of submarine anti-submarine warfare, single acoustic homing torpedo or parallel salvo acoustic homing torpedo to attack enemy submarine is usually used. According to the search sector of torpedo and the method of submarine avoiding torpedo maneuver, the model for submarine running out of search zone is established. Therefore, the necessity of using parallel salvo in anti-submarine warfare is verified. On this basis, the calculation model of firing parameters is established, and the simulation results show that the Optimization of firing parameters has great influence on the hit probability of parallel salvo. The research results have certain reference value for implementation.
Direct synthesis of WSe2/PtSe2 heterostructures
Authors: Minev N , Dimitrov D , Dimov D , Rafailov P , Napoleonov B , Videva V , Kovacheva D , Strijkova V , Avramova I , Dikov H , Marinova V 
Published: February 2024

Abstract
The results of a successful synthesis of a WSe2/PtSe2 heterostructures are presented. High quality crystalline films were achieved through a one–step selenization of a pre-deposited tungsten film with pre-deposited platinum as an underlayer. The role of the PtSe2 layer, formed during selenization, was to assists the growth of crystalline WSe2. The existence of WSe2 was confirmed using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The crystallinity of the samples was investigated using X-ray diffraction (XRD). Surface measurements were performed using atomic force microscopy (AFM).
Investigation of optical properties of nanoparticle-dispersed polymer films
Authors: Kasarova S , Sultanova N , Kiryakova D , Nikolov I 
Published: February 2024

Abstract
Composite films of polystyrene and polymethyl methacrylate with added ZnO and ZrO2 nanoparticles have been prepared. Effective medium approximations have been applied to calculate final refractive indices. Results are compared to the experimental values of films with different thickness. Transparency of neat polymer and nanocomposite layers is also studied.
Influence of the pulse duration at the laser processing of nitride ceramics
Authors: Nedyalkov N , Dikovska A , Dilova T , Atanasova G 
Published: February 2024

Abstract
This paper presents results on laser ablation of AlN and Si3N4 ceramics by laser pulses with different duration. Three types of laser systems, a Nd:YAG one, operated at wavelength of 1064 nm and pulse duration of 15 ns, a Nd:YAG, operated at wavelength of 1064 nm and pulse duration of 10 ps, and a femtosecond laser system, operated at 800 nm, with a pulse duration of 75 fs, are used for experiments. Details on the ablation efficiency, surface morphology, and the chemical composition of the irradiated zones as a function of the pulse duration are given and discussed. It is demonstrated that the ablation rate (ablation depth per pulse) is highest for processing with nanosecond pulses and it is lowest for the femtosecond regime. The laser ablation results in significant change of the surface morphology, as its characteristics are influenced by the pulse duration. For all pulse durations conditions for formation of ripples structures are found. The ablation process is realized by decomposition of the ceramics and the composition of the remaining surface layer is governed by oxidation and carbonization.
Remote detection of the conductivity of current-carrying metallized traces
Authors: Taskova E , Stankova N , Petrov N , Ranev V , Nedyalkov N , Armyanov S , Andreeva C 
Published: February 2024

Abstract
The weak magnetic fields generated by a current-carrying metallized traces are detected in view of their applications in bionic systems and neural-electrode interface technologies. The traces are formed by femtosecond laser processing of the surface of polydimethylsiloxane polymer substrate and further functionalization by electroless metallization. The measurements are performed by means of magneto-optical spectroscopy involving two optical beams, serving as pump and probe, where the magnetic field sensor is 87Rb atoms confined in a paraffin-coated optical cell. The experimental results show the feasibility of remote detection of the conductivity of metallized nickel traces.
Co-sputtered CuO/TiO2 coatings with varying copper content deposited on Ti6Al4V alloy
Authors: Nikolova M P , Tzvetkov I 
Published: February 2024

Abstract
In this study, mosaic target material of titanium (Ti) and copper (Cu) was used to deposit CuO/TiO2 coatings on Ti6Al4V alloy. The aim was to examine the change in composition, structure and adhesion of the deposited films on titanium alloy when varying the titanium/copper (20:1, 41:1, 179:1, 418:1 and 837:1) ratio of the target material. The coatings were obtained by sputtering in a glow-discharge in a pure O2 atmosphere for a deposition time of 240 min. All coatings showed homogenous Cu distribution and the film thickness decreased with the reduction of Cu content in the composite target. Cu content in the coatings followed a power function of decrease with reduction of Ti-Cu content in the target while the increase of Ti showed logarithmic dependence. In all coatings, anatase and rutile TiO2 phases were detected whereas Cu atoms participated only in the formation of monoclinic CuO. TiO2-rich coatings demonstrated better adhesion to the Ti6Al4V alloy, whereas the critical loads of CuO-rich films were dependent on coating thickness.
Electron beam melting efficiency at multiple hafnium e-beam processing
Authors: Markov M , Stefanova V , Vutova K , Vassileva V , Tanaka T , Kakugawa K 
Published: February 2024

Abstract
The method of electron beam melting and vacuum refining has clear advantages over other metallurgical methods since it enables manufacturing of refractory and chemically active metals. This study focuses on the efficiency of removing impurities from technogenic hafnium under multiple electron beam melting. Assessments are performed on the efficiency of double and triple e-beam melting processing of refractory metal hafnium. The influence of different e-beam melting technological modes on the refining effectiveness is investigated. A highest hafnium purity of 99.2% was achieved after double and triple e-beam refinements of the investigated materials, with the highest process efficiency reaching 61.58% and 51.07%, respectively.
First experiments looking at the symmetry of the plasma formation phase of the dense plasma focus using d-dot probes
Authors: Blagoev A B , Yordanov V , Auluck S K H 
Published: February 2024

Abstract
The Dense Plasma Focus is being considered as the basis of sophisticated technologies such as an energy producing fusion machine, space propulsion for interplanetary and deep space missions and nanomaterial fabrication. However, there are problems with ensuring a reliable and reproducible operation of the device. It does not operate well immediately after the device is exposed to atmosphere and re-evacuated. A series of training shots is required after which the operation stabilizes until the vacuum chamber is opened again. Our previous work on numerical simulation of the formation phase shows that plasma behaviour on hydrodynamic time scales is difficult to predict because of simultaneous presence of many time scales and scale lengths. A systematic understanding of the role of the training shots in the formation process therefore requires a new experimental approach. This paper presents the first experiments looking at the symmetry of the discharge during its formation phase. The new diagnostic uses 3 d-dot probes symmetrically placed outside the squirrel cage cathode looking at the insulator through gaps between cathode rods. First results are presented and discussed.
Association between social vulnerability and place of death during the first 2 years of COVID-19 in Massachusetts
Authors: Charpignon Marie-Laure , Onofrey Shauna , Chen Yea-Hung , Rewegan Alex , Glymour Medellena Maria , Klevens R Monina , Majumder Maimuna Shahnaz 
Published: February 2024

Abstract
We investigated the relationship between individual-level social vulnerability and place of death during the infectious disease emergency of the COVID-19 pandemic in Massachusetts. Our research represents a unique contribution by matching individual-level death certificates with COVID-19 test data to analyse differences in distributions of place of death.
Impact of a pharmacy technician on an interprofessional antithrombotic stewardship program at an academic medical center
Authors: Hammonds William M , Bowman Emily A , Chiplinski Amber N , Keeting Tessa A , Pagenhardt Sarah M , Valdez Patricia , Street Ashley F , Caccamo Marco , O’Neil Daniel P , Peters Julie E , Stoffa Stephanie L 
Published: February 2024

Abstract

Purpose
The need for monitoring and standardization of anticoagulation management has garnered the attention of national organizations, driving the implementation of antithrombotic stewardship programs (ASPs). Established ASPs have highlighted interdisciplinary collaboration between physicians, nurses, and pharmacists and demonstrated financial benefits and positive patient care outcomes. While pharmacy technicians are key members of the pharmacy profession, they are rarely utilized to expand clinical programs. The aim of this report is to describe the impact of adding a pharmacy technician to an ASP at an academic medical center.

Summary
The departments of pharmacy and quality at West Virginia University Hospitals (WVUH) developed a business plan and financially justified an ASP. The ASP was implemented in January 2022 and consisted of 2 full-time clinical pharmacist specialists, 1 full-time clinical pharmacy technician, 2 full-time clinical nurse specialists, and 1 part-time physician medical director. The clinical pharmacy technician’s primary role was to review patients’ sequential compression device (SCD) compliance and newly started oral anticoagulants prior to discharge. The clinical nurse specialists educated patients newly started on oral anticoagulants within 24 hours of discharge and triaged any postdischarge medication access issues. The medical director provided high-level program oversight and acted as a clinical consultant on complex patient cases. In the first 6 months after the program’s implementation, the clinical pharmacy technician made 174 recommendations to the clinical pharmacist specialists regarding discharge transitions of care and assessed SCD compliance in 246 patients. Of the 246 patients assessed, 217 patients (88%) were deemed to be noncompliant.

Conclusion
The pharmacy department at WVUH successfully justified and implemented an interprofessional ASP at an academic medical center, which is the first ASP to date to incorporate a clinical pharmacy technician.
The potential of historical spy-satellite imagery to support research in ecology and conservation
Authors: Munteanu Catalina , Kraemer Benjamin M , Hansen Henry H , Miguel Sofia , Milner-Gulland E J , Nita Mihai , Ogashawara Igor , Radeloff Volker C , Roverelli Simone , Shumilova Oleksandra O , Storch Ilse , Kuemmerle Tobias 
Published: February 2024

Abstract
Remote sensing data are important for assessing ecological change, but their value is often restricted by their limited temporal coverage. Major historical events that affected the environment, such as those associated with colonial history, World War II, or the Green Revolution are not captured by modern remote sensing. In the present article, we highlight the potential of globally available black-and-white satellite photographs to expand ecological and conservation assessments back to the 1960s and to illuminate ecological concepts such as shifting baselines, time-lag responses, and legacy effects. This historical satellite photography can be used to monitor ecosystem extent and structure, species’ populations and habitats, and human pressures on the environment. Even though the data were declassified decades ago, their use in ecology and conservation remains limited. But recent advances in image processing and analysis can now unlock this research resource. We encourage the use of this opportunity to address important ecological and conservation questions.
Effect of thyroid hormone replacement therapy on mortality rate in patients undergoing total or hemithyroidectomy for benign multinodular goitre
Authors: Nordenström Erik , Ranstam Jonas , Bergenfelz Anders 
Published: February 2024

Abstract

Background
Thyroid surgery for benign non-toxic nodular goitre is a common endocrine surgical procedure. It is not known whether thyroid hormone replacement therapy following surgery for benign thyroid disease influences mortality or morbidity rates.

Methods
A retrospective observational study was conducted using national registries in Sweden. Overall mortality and morbidity rates were compared for patients with or without thyroid hormone replacement therapy in patients operated on with hemithyroidectomy or total thyroidectomy for a diagnosis of benign non-toxic nodular goitre.

Results
Between 1 July 2006 and 31 December 2017, 5573 patients were included, 1644 (29.5%) patients were operated on with total thyroidectomy and 3929 patients with hemithyroidectomy. In the hemithyroidectomy group, 1369 (34.8%) patients were prescribed thyroid hormone replacement therapy in the follow-up. The patients who underwent hemithyroidectomy and did not use thyroid hormone replacement therapy in the follow-up had a standard mortality ratio of 1.31 (95% confidence interval, 1.09–1.54). The mortality ratio was not increased in patients who underwent total thyroidectomy or hemithyroidectomy and used thyroid hormone replacement therapy. The risk of death analysed by multivariable Cox regression for patients operated on with hemithyroidectomy without later thyroid hormone replacement therapy, adjusted for age and sex, showed an increased hazard ratio of 1.65 (1.19–2.30) compared with hemithyroidectomy with hormone replacement therapy.

Conclusion
Patients subjected to hemithyroidectomy without later hormone replacement therapy had a 30% higher risk of death compared with the normal Swedish population and a 65% increased risk of death compared with patients undergoing hemithyroidectomy with postoperative hormone replacement therapy.
Cognitive and neural mechanisms of voluntary versus forced language switching in Chinese–English bilinguals: an fMRI study
Authors: Geng Libo , Zhao Xinyu , Xu Qihui , Wu Haiyan , Hu Xueping , Liu Zhiyuan , Ming Lili , Xue Zixuan , Yue Chenyi , Yang Yiming 
Published: February 2024

Abstract
The ecological validity of bilingual code-switching has garnered increasing attention in recent years. Contrary to traditional studies that have focused on forced language switching, emerging theories posit that voluntary switching may not incur such a cost. To test these claims and understand differences between forced and voluntary switching, the present study conducted a systematic comparison through both behavioral and neural perspectives. Utilizing fMRI alongside picture-naming tasks, our findings diverge from prior work. Voluntary language switching not only demonstrated switching costs at the behavioral level but also significantly activated brain regions associated with inhibitory control. Direct comparisons of voluntary and forced language switching revealed no significant behavioral differences in switching costs, and both shared several common brain regions that were activated. On the other hand, a nuanced difference between the two types of language switching was revealed by whole-brain analysis: voluntary switching engaged fewer language control regions than forced switching. These findings offer a comprehensive view of the neural and behavioral dynamics involved in bilingual language switching, challenging prior claims that voluntary switching imposes no behavioral or neural costs, and thus providing behavioral and neuroimaging evidence for the involvement of inhibitory control in voluntary language switching.