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37th International Conference on Lightning Protection, ICLP 2024

作者： Jayasinghe, Hasupama Arevalo, Liliana Morrow, richard Cooray, Vernon Department of Electrical Engineering Uppsala University Uppsala Sweden Hitachi Energy - HVDC R&D Department Sweden Department of Applied Physics Sydney University Australia

ISBN: (纸本)9783800764174

Lightning involves complex physical processes in atmospheric discharges, beginning with the development of streamer discharges. Therefore, to understand the mechanism of streamer discharges, it is important to develop a computationally efficient and an accurate numerical model. In this paper, we present the results of a 1.5-dimensional (1.5d) streamer discharge simulation using the well-established explicit finite difference method (Fd) with flux-corrected transport (FCT) method. The method was applied to a streamer propagating in a 1.25cm plane-plane air gap in standard atmospheric pressure and temperature. We compared our results to those from a previously published two-dimensional (2d) axisymmetric streamer paper which is focused on the same air gap but using different numerical approaches. One can observe that the electric field is obtained with good accuracy in this 1.5d numerical simulation. The streamer position and the streamer bridging time agree with 2d results. This model has the potential to deal with moving non-uniform meshes. © 2024 IEEE, © VdE VErLAG GMBH ∙ Berlin ∙ Offenbach.

关键词： Electric discharges

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Effect of boriding on wear and fatigue life of WC-Co die inserts in cold forming

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Engineering Failure Analysis 2025年 179卷

作者： Kubra Ozturk Guler Bahadir Uyulgan Burak Hizli Umut Ince Department of Metallurgical and Materials Engineering Dokuz Eylul University İzmir Turkey The Graduate School of Natural and Applied Sciences Department of Metallurgical and Materials Engineering Dokuz Eylul 35390 Izmir Turkey R&D Center Norm İzmir Cıvata San. ve Tic. A.Ş. AOSB İzmir Turkey

Cold forging is a key manufacturing process in fastener production, utilizing multi-stage die systems to plastically deform materials under high compressive stresses. In cold forming operations such as extrusion, reduction, and head forming, WC-Co materials are widely employed in die applications, selected based on the specific requirements of the process. These die materials used in cold forming must exhibit high wear resistance and fatigue strength due to the substantial forming forces that generate significant stresses within the dies. Boriding, a surface treatment method, is applied to enhance these mechanical properties. This study investigates the effects of pack-boriding treatment on the fatigue life and wear properties of WC-Co material containing 19 % Co, which are used as die inserts in cold forging die systems. Three sets of samples were pack-borided using EKABOr-2 boron powder at 1000 °C, 950 °C, and 900 °C for 4 h under each temperature condition to accomplish this process. Following the pack-boriding process, pin-on-plate wear tests were conducted under both non-lubricated and lubricated conditions to evaluate the wear performance of the samples. Three-point bending fatigue tests were performed to assess the fatigue behavior of the borided samples. After the fatigue test, Goodman-Haigh diagrams were obtained from the experimental results to be utilized in predictive die-life calculations. X-ray diffraction (Xrd) analysis confirmed the formation of CoB, Co 2 B, WB 2 and W 2 CoB 2 phases in the borided layer. results indicate that increasing boriding temperature significantly improves wear resistance and surface hardness, with the highest microhardness (4104 HV 0 . 1 ) and the lowest wear track width (183 µm non-lubricated, 70.76 µm lubricated) measured at 1000 °C. However, the thick and brittle boride layer induced stress concentrations, negatively affecting the material’s fatigue performance. According to the Goodman-Haigh diagrams, the highest fatigue

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3d-based Visual Assistance System for Teleoperation

3D-based Visual Assistance System for Teleoperation

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International Conference on Control, Automation and Systems

作者： Ga-ram Jang Yong-deuk Shin Jae-Shik Yoon Ji-Hun Bae Jae-Han Park Moon-Hong Baeg Department of Applied Robot Technology Korea Institute of Industrial Technology (KITECH) Ansan R&D Center

ISBN: (纸本)9781467322478

In this paper, we propose a 3d-based visual assistance system for teleoperation using 3d point cloud data. In a teleoperating system, it is essential to provide the teleoperator with highly realistic information. By using 3d point cloud data, the teleoperator can observe the working environment from different viewpoints and apply various task-solving methods to it.

关键词： Teleoperation 3d point cloud Visual assistance system

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Synthesis of Lithium manganese oxide (LMO) and Ti-Substituted LMO Sorbents (LMTO) for Lithium Extraction in a Spray drying Process

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ChemSusChem 2025年 e202500530页

作者： Laura Herrmann Nicole Bohn Alina Pfau Thomas Kölbel Helmut Ehrenberg Joachim Binder Fabian Jeschull EnBW Regional AG R&D Department GERMANY. KIT: Karlsruher Institut fur Technologie IAM-ESS GERMANY. Karlsruhe Institute of Technology Institute for Applied Materials - Energy Storage Systems Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen GERMANY.

Lithium manganese oxides (LMO) are highly promising sorbents for lithium extraction from Li+-containing brines with high salt contents due to their high sorption capacity and high selectivity towards lithium. However, conventional synthesis routes are limited in scale. Therefore, herein a novel spray drying method is presented, enabling a scalable synthesis of LMO sorbents for Li+-extraction. The ion exchange material was studied in both synthetic LiCl solutions and two different geothermal brines from the Upper rhine valley, demonstrating improved Li selectivity and extraction capabilities compared to materials from hydrothermal synthesis approaches. The extraction behavior in relevant mildly acidic environments was studied in detail. Further material improvements were achieved by substituting a fraction of Mn by Ti, which greatly reduced the dissolution of manganese during acid treatment in the first 5 extraction cycles from 5.6% to only 1.8%. In addition, the maximum sorption capacity of the Ti-containing LMO (LMTO) could be further increased from 5.05 mmol g-1 for LMO (35.1 mg g-1 ) to 5.66 mmol g-1 for LMTO (39.3 mg g-1 ) under optimized m/V-ratios. Hence, the results reported herein present a pathway towards LMO-based ion exchange materials for the direct lithium extraction (dLE) on an industrial scale.

关键词： direct lithium extraction (dLE) geothermal brine lithium manganese oxide (LMO) lithium recovery spray-drying

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Genetic Algorithm-Based Fundamental Frequency Optimization of Laminated Composite Shells Carrying distributed Mass

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Journal of The Institution of Engineers (India): Series C 2022年第3期103卷 389-401页

作者： Pal, Subham Kalita, Kanak Haldar, Salil Department of Aerospace Engineering and Applied Mechanics Indian Institute of Engineering Science and Technology Shibpur711 103 India Department of Mechanical Engineering Vel Tech Rangarajan Dr Sagunthala R&D Institute of Science and Technology Avadi600 062 India

Composite plates and shells are an inevitable part of the modern structural, aerospace and marine industry. Load-carrying plates and shells must be optimized from a frequency viewpoint to avoid resonance. In the present study, a global optimization framework is developed by combining the iterative improvement ability of genetic algorithm (GA) with the brute accuracy of finite element (FE) method to optimize the fundamental frequency of composite shells. Since composites are weak in shear, the shear deformation effect is considered by using the first-order shear deformation theory in the finite element formulation. The ply angles are considered as the design variables. However, only discrete ply angles with 5° increments in the ± 90° search space are considered. Various numerical studies are carried out to check the validity and accuracy of the present FE-GA approach. A wide range of results for rectangular and cylindrical shell panels with different radius of curvatures, boundary conditions and carrying distributed mass at different positions are presented. © 2022, The Institution of Engineers (India).

关键词： Genetic algorithms

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Interactive remote robot operation framework for rescue robot

Interactive remote robot operation framework for rescue robo...

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IEEE International Workshop on Safety, Security, and rescue robotics (SSrr)

作者： Yong-deuk Shin Jae-Han Park Ga-ram Jang Jae-Shik Yoon Moon-Hong Baeg Applied Robot Technology R&D Group Korea Institute of Industrial Technology Korea

Situation awareness and its ambiguities are some of the main problems for rescue robotics. In a disaster area, there are many obstacles and confined passages. The operator must perceive the environment and decide the robot motion based on limited sensor data. These make it difficult for the operator to perceive the situation. The operator should be aware of the relative size of the obstacles in comparison with the rescue robot and the direction of the robot to navigate the disaster area and avoid collisions with obstacles. In this paper, we propose a software framework to reduce these ambiguities. A 3d map constructed with a 3d laser scanner and a robot model in this map can reduce the ambiguities. We also estimate future robot paths using the control inputs. Then, we perform collision detection in the expected paths and their neighbors. The collision results are displayed in the reconstructed 3d map using iterative closest points(ICP) algorithm. In this paper, we define interactive remote robot operation(IrrO) by extracting the common properties for reducing the ambiguities and abstracting them. The IrrO is composed of two parts, a simulation and evaluation step for the future robot motion and an interactive user interface system.

关键词： robot sensing systems Three-dimensional displays Irrigation Image reconstruction robot motion robot kinematics

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TeO2: As a key component in improving radiation shielding of B2O3-based glass systems

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radiation Physics and Chemistry 2025年

作者： Sayyed, M.I. Yasmin, Sabina Faruque, M.r.I. Abdullah, S. Mahmoud, K.A. Khandaker, M.U. Department of Physics Faculty of Science Isra University Amman Jordan Renewable Energy and Environmental Technology Center University of Tabuk Tabuk47913 Saudi Arabia Universiti Kebangsaan Malaysia Selangor Bangi43600 UKM Malaysia R&D Office Vice Presidency for Scientific Research and Innovation Imam Abdulrahman Bin Faisal University P.O. Box 1982 Dammam31441 Saudi Arabia Ural Federal University 19 Mira St Yekaterinburg620002 Russia Applied Physics and Radiation Technologies Group CCDCU Faculty of Engineering and Technology Sunway University Selangor Bandar Sunway47500 Malaysia Faculty of Graduate Studies Daffodil International University Daffodil Smart City Birulia Savar Dhaka1216 Bangladesh Department of Physics College of Science Korea University 145 Anam-ro Seongbuk-gu Seoul02841 Korea Republic of Department of Physics and Technical Sciences Western Caspian University Baku Azerbaijan

New glasses with enhanced radiation shielding characteristics have potential applications in different fields requiring radiation protection. In the context of radiation shielding applications, this work aims to develop new lead-free B2O3–TeO2–Bi2O3–ZnO–CaO glass systems. A 15–30 mol% increase in TeO2 concentration results in a 4.070–4.498 g/cm3 density increase. The influence of increasing the TeO2 doping concentration on the mechanical properties of the prepared boro-tellurite glass was utilized using the Makishima-Makinze theory. Additionally, the influence of raising the TeO2 concentration on the radiation shielding properties of the prepared boro-tellurite glass was studied using the Monte Carlo simulation. The Monte Carlo simulation confirms that a 15–30 mol% TeO2 increase enhances LAC values, reducing half-value layer thickness (HVL), and improving radiation shielding. However, mechanical properties such as hardness and Young's modulus slightly decrease due to TeO2 substitution. © 2025 Elsevier Ltd

关键词： radiation shielding

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Instance segmentation based recognition system tracking tomatoes by ripeness in natural light conditions

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Journal of Institute of Control, robotics and Systems 2020年第11期26卷 940-948页

作者： Lee, Woo-Young Ko, Kwang Eun Kang, Jaehyeon Park, Hyun Ji Jang, Inhoon Applied Robot R&D Department Korea Institute of Industrial Technology Korea Republic of Department of computer Science & Engineering Hanyang University Korea Republic of

This paper describes a tomato recognition system to be applied to a harvesting robot used in farms under natural light conditions. The tomato recognition system is composed of a stereo camera, light, deep learning based instance segmentation model and Kalman filter based object tracking algorithm. In order to train the instance segmentation model, a large-scale dataset of the actual smartfarm background is made, and performance verification is performed on the test dataset. The average precision of the deep learning based instance segmentation model achieved 96.8% of performance when the threshold of the prediction score for classifying ripeness is over 0.75 (Table. 3), and the multiple object tracking accuracy of the Kalman filter based tracking method is approximately 74.3%. © ICrOS 2020.

关键词： Kalman filters

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Chatter Suppression of External Grooving Tools

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Procedia CIrP 2017年 58卷 216-221页

作者： J. Saffury Applied Mechanics Department R&D tool Division ISCAR LTD Israel

Generating deep grooves using long blades is a challenge due to excessive chatter vibrations. In the present paper, an analytical simplified solution of the critical grooving width is obtained. It is found that a cross FrF of the tool dominates the solution. A conventional grooving tool with long overhang is tested where chatter vibrations develop. A new tool with attached dynamic Vibration Absorber (dVA) is designed to replace the conventional one and a novel dVA tuning mechanism is presented. The cross FrF real part is optimized via modal experiments and the tuning mechanism. Machining experiments are conducted for both grooving systems in order to verify the model predictions. Grooving is unstable using the conventional blade while it is stable with the tuned new one.

关键词： Chatter Stability lobes Grooving dynamic vibration absorber tuning

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Widely Tunable and High Power Multi-THz Transients from a sub-ps Yb:YAG Thin-disk System and Parametric Amplification

Widely Tunable and High Power Multi-THz Transients from a su...

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CLEO: Science and Innovations, S and I 2022

作者： Schoenfeld, C. Heinrich, A.-C. Feuerer, L. Bossini, d. Sarkisov, S. Leitenstorfer, A. Department of Physics Center for Applied Photonics University of Konstanz KonstanzD-78464 Germany Laboratory of Optical Structures and Applied Photonics R&D Center «Advanced Electronic Technologies» Tomsk State University Tomsk634050 Russia

Phase-locked mid-infrared pulses tunable between 18 and 50 THz are generated with peak electric fields of 150 MV/cm. The compact and low-noise system aims at subcycle studies of matter under nonlinear driving or adiab... 详细信息

ISBN: (纸本)9781557528209

关键词： Yttrium aluminum garnet

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