• 제목/요약/키워드: mechanical device

검색결과 2,854건 처리시간 0.024초

인출력 저감을 통한 SSD Test Gender의 장수명 설계 (Long Life Design of SSD Test Gender by Reducing Ejecting Force)

  • 김재경;박형석;이기석;전의식
    • 반도체디스플레이기술학회지
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    • 제19권4호
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    • pp.139-144
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    • 2020
  • Recently, the electronic equipment industry has become active due to the continuous increase in portable storage media with high-speed information communication, and in particular, the production of SSD(Solid State Drives) for miniaturization of mobile devices and high-speed information communication has increased rapidly. When the SSD is ejecting in the SSD test gender, the necessary ejecting force must be kept constant to have a lifespan applicable to the test device. When the ejecting force increased, it leads to wear of the link for ejecting, which causes a problem in that repeated durability decreases and the ejecting of the SSD becomes impossible. In this paper, the repeated durability test analysis according to the material and the reducing ejecting force design were performed to increase the life of the test gender for SSD inspection. The wear level of the pusher head and ejector was analyzed through repeated durability tests according to the material of the pusher head. The validity of the design was verified through the ejecting force test and repeated durability test of the Test gender, which was designed by carrying out the design to reduce the size and ejecting force of the test gender.

리튬이온 배터리의 분리막 손상 요인별 방전펄스의 검출과 분석 (Detection and Analysis of Discharge Pulses by Failure Mechanisms of the Separator inside Lithium-Ion Batteries)

  • 임승현;이경렬;김남훈;김동언;길경석
    • 한국전기전자재료학회논문지
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    • 제34권5호
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    • pp.327-332
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    • 2021
  • Lithium-ion batteries (LIBs) have become a main energy storage device in various applications, such as portable appliances, renewable energy facilities, and electric vehicles. However, the poor thermal stability of LIBs may cause explosion or fire. The thermal runaway is the result of a failure of the separator inside LIB. Damages like tearing, piercing, and collapsing of the separator were simulated in a mechanical, an electrical, and a thermal way, and small discharge pulses of a few mV were detected at the time of separator damages. From the experimental results, this paper provided a method that can identify the separator failure before thermal runaway in the aspect of a potential explosion and fire prevention measures.

송풍 시스템의 공기유량측정 방법에 관한 연구 (Research on Air Flow Rate Test Method for Blower System)

  • 이준식
    • 한국산업융합학회 논문집
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    • 제25권1호
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    • pp.55-60
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    • 2022
  • This study conducted the measurements of air flow rate for blower systems with experiment and numerical. A new airflow rate test method is suggested, with which it is possible to accurate measurements and calculate the air flow rate for blower systems. The blower(axial fan) is an industrial fluid machine device that supplies a large amount of air by driving an impeller with an electric motor, and it is widely used throughout the industry such as steel, power plant, chemical, semiconductor, LC D, food, and cement. The airflow from the blower is for exchanging the heat in the cooling unit or heat exchanger. The temperature of coolants and hydraulic oil primarily depends on the amount of airflow rate through the cooling package so its accurate estimation is very important. Moreover, it required a larger investment in time and cost since it could not be executed until the system is actually made. Therefore, this research is intended to examine the phenomenon of air flow pattern when testing air flow rate, suggested new test method, and show the result of the validation test.

Solution-Processed Two-Dimensional Materials for Scalable Production of Photodetector Arrays

  • Rhee, Dongjoon;Kim, Jihyun;Kang, Joohoon
    • 센서학회지
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    • 제31권4호
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    • pp.228-237
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    • 2022
  • Two-dimensional (2D) nanomaterials have demonstrated the potential to replace silicon and compound semiconductors that are conventionally used in photodetectors. These materials are ultrathin and have superior electrical and optoelectronic properties as well as mechanical flexibility. Consequently, they are particularly advantageous for fabricating high-performance photodetectors that can be used for wearable device applications and Internet of Things technology. Although prototype photodetectors based on single microflakes of 2D materials have demonstrated excellent photoresponsivity across the entire optical spectrum, their practical applications are limited due to the difficulties in scaling up the synthesis process while maintaining the optoelectronic performance. In this review, we discuss facile methods to mass-produce 2D material-based photodetectors based on the exfoliation of van der Waals crystals into nanosheet dispersions. We first introduce the liquid-phase exfoliation process, which has been widely investigated for the scalable fabrication of photodetectors. Solution processing techniques to assemble 2D nanosheets into thin films and the optoelectronic performance of the fabricated devices are also presented. We conclude by discussing the limitations associated with liquid-phase exfoliation and the recent advances made due to the development of the electrochemical exfoliation process with molecular intercalants.

송전선로용 고전압 절연체의 최적 형상에 대한 유한요소 해석 (Finite Element Analysis for the Optimal Shape of the High Voltage Insulator for Power Transmission Lines)

  • 김태용;산얄 심피;라벨로 마데우스;이준신
    • 한국전기전자재료학회논문지
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    • 제35권1호
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    • pp.66-71
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    • 2022
  • The insulator used for the transmission line is a device that is bonded with a cap, pin, ceramic, and cement to withstand insulation capacity and mechanical load. The insulator design can help to reduce the dispersion of the electric field; thus, the optimization of today's design, especially as demanded power grows, is critical. The designs of four manufacturers were used to perform a comparative analysis. Under dry circumstances of the new product, an electric field distribution study was done with no pollutants attached. Manufacturer D's design has the best voltage uniformity of 24.33% and the arc length of 500 mm or more. Manufacturer C's design has an equalizing voltage of more than 2% higher than that of other manufacturers. The importance of the design of the insulator and the number of connections according to the installation conditions is very efficient for transmission lines that will increase in the future.

Development and performance evaluation of large-area hybrid gamma imager (LAHGI)

  • Lee, Hyun Su;Kim, Jae Hyeon;Lee, Junyoung;Kim, Chan Hyeong
    • Nuclear Engineering and Technology
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    • 제53권8호
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    • pp.2640-2645
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    • 2021
  • We report the development of a gamma-ray imaging device, named Large-Area Hybrid Gamma Imager (LAHGI), featuring high imaging sensitivity and good imaging resolution over a broad energy range. A hybrid collimation method, which combines mechanical and electronic collimation, is employed for a stable imaging performance based on large-area scintillation detectors for high imaging sensitivity. The system comprises two monolithic position-sensitive NaI(Tl) scintillation detectors with a crystal area of 27 × 27 cm2 and a tungsten coded aperture mask with a modified uniformly redundant array (MURA) pattern. The performance of the system was evaluated under several source conditions. The system showed good imaging resolution (i.e., 6.0-8.9° FWHM) for the entire energy range of 59.5-1330 keV considered in the present study. It also showed very high imaging sensitivity, successfully imaging a 253 µCi 137Cs source located 15 m away in 1 min; this performance is notable considering that the dose rate at the front surface of the system, due to the existence of the 137Cs source, was only 0.003 µSv/h, which corresponds to ~3% of the background level.

FPGA application for wireless monitoring in power plant

  • Kumar, Adesh;Bansal, Kamal;Kumar, Deepak;Devrari, Aakanksha;Kumar, Roushan;Mani, Prashant
    • Nuclear Engineering and Technology
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    • 제53권4호
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    • pp.1167-1175
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    • 2021
  • The process of automation and monitoring in industrial control system involves the use of many types of sensors. A programmable logic controller plays an important role in the automation of the different processes in the power plant system. The major control units are boiler for temperature and pressure, turbine for speed of motor, generator for voltage, conveyer belt for fuel. The power plant units are controlled using microcontrollers and PLCs, but FPGA can be the feasible solution. The paper focused on the design and simulation of hardware chip to monitor boiler, turbine, generator and conveyer belt. The hardware chip of the plant is designed in Xilinx Vivado Simulator 17.4 software using VHDL programming. The methodology includes VHDL code design, simulation, verification and testing on Virtex-5 FPGA hardware. The system has four independent buzzers used to indicate the status of the boiler, generator, turbine motor and conveyer belt in on/off conditions respectively. The GSM is used to display corresponding message on the mobile to know the status of the device in on/off condition. The system is very much helpful for the industries working on plant automation with FPGA hardware integration.

격막 파열과 충격파 터널 시험 시간에 대한 수치 연구 (Effect of a Diaphragm Opening Process on Flow Condition in Shock Tunnel)

  • 김세환
    • 한국추진공학회지
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    • 제25권6호
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    • pp.20-28
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    • 2021
  • 극초음속 유동 시험에 활용되고 있는 충격파 터널 등은 원하는 시험 조건을 얻기 위해 격막의 파열 압력비를 맞추어 운용한다. 주로 금속 재질로 이루어진 격막은 정확한 압력비를 맞추기 위해 특정 형태로 가공하거나 강제 파열 장치를 사용하여 개방한다. 격막의 개방 과정은 수백 microsecond 동안 파열과 변형을 통해 이루어지는데, 동일한 압력비에서도 개방 정도와 개방 소요 시간에 따라 시험 조건이 달라질 수 있을 것으로 예상된다. 본 연구에서는 격막의 두께 및 재질 차이를 반영할 수 있는 파열모델을 적용하여 수치 해석을 수행하고 충격파의 형성과 정체 조건의 특성에 대해 살펴보았다. 격막 파열로 인해 생성된 충격파의 속도는 격막 개방 속도에 비례하였으며, 격막의 최종 개폐율 및 소요 시간에 따라 저압관 끝단에 형성되는 정체 압력과 시험 시간에 차이가 나타나는 것을 확인할 수 있었다.

Compound damping cable system for vibration control of high-rise structures

  • Yu, Jianda;Feng, Zhouquan;Zhang, Xiangqi;Sun, Hongxin;Peng, Jian
    • Smart Structures and Systems
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    • 제29권4호
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    • pp.641-652
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    • 2022
  • High-rise structures prone to large vibrations under the action of strong winds, resulting in fatigue damage of the structural components and the foundation. A novel compound damping cable system (CDCS) is proposed to suppress the excessive vibrations. CDCS uses tailored double cable system with increased tensile stiffness as the connecting device, and makes use of the relative motion between the high-rise structure and the ground to drive the damper to move back-and-forth, dissipating the vibration mechanical energy of the high-rise structure so as to decaying the excessive vibration. Firstly, a third-order differential equation for the free vibration of high-rise structure with CDCS is established, and its closed form solution is obtained by the root formulas of cubic equation (Shengjin's formulas). Secondly, the analytical solution is validated by a laboratory model experiment. Thirdly, parametric analysis is conducted to investigate how the parameters affect the vibration control performance. Finally, the dynamic responses of the high-rise structure with CDCS under harmonic and stochastic excitations are calculated and its vibration mitigation performance is further evaluated. The results show that the CDCS can provide a large equivalent additional damping ratio for the vibrating structures, thus suppressing the excessive vibration effectively. It is anticipated that the CDCS can be used as a good alternative energy dissipation system for vibration control of high-rise structures.

열안정성을 고려한 초소형 정보저장기기용 액추에이터 구조설계 (Structural design of small form factor swing arm type actuators with thermal stability)

  • 박철;유정훈;박노철;박영필;도야건;중촌자남
    • 정보저장시스템학회논문집
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    • 제2권3호
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    • pp.208-213
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    • 2006
  • The present state of the design of swing arm actuators for optical disc drives is to obtain the high efficient dynamic characteristics within a very compact volume. As a necessary consequence, the need of the small form factor (SFF) storage device has been arisen as major interests in the information storage technology. In this paper, we suggest the miniaturized swing arm type actuator that has high efficient dynamic characteristics for SFF optical disk drive (ODD). For the operating mechanism, it uses a tracking electromagnetic (EM) circuit for a focusing motion together. Moreover, due to the size constraint, the thermal stability of optical head is important. Therefore, the actuator is designed to emit the heat, which is generated by optical pick-up, along the actuator body easily. Initial model is designed based on the topology optimization method considering the thermal conductivity. Then, the structural parts of the actuator are modified to maintain the high sensitivity and to have wide control bandwidth by the design of experiments method (DOE) and new concept of decreasing mass and inertia. Finally, a swing arm type actuator for SFF ODD is suggested and its dynamic characteristics are verified.

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