• Title/Summary/Keyword: Through Resistance

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The 4-channel Multiple Contact Resistance Measurement Systems using MQTT Broker Server for AC 22.9 kV COS/Lightning Arrester (MQTT 브로커 서버를 이용한 AC 22.9 kV 차단기/피뢰기의 4-채널 다중 접촉저항 측정 시스템)

  • Ra-Yun Boo;Jung-Hun Choi;Myung-Eui Lee
    • Journal of Advanced Navigation Technology
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    • v.27 no.2
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    • pp.203-208
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    • 2023
  • In this study, we propose a method to improve the precision of contact resistance measurement circuits using constant current method and voltage drop method, and implement a dashboard that monitors the measured data of contact resistance measurement systems through MQTT broker server. The contact resistance measurement system measures the resistance value and transmits the measured value to the MQTT broker server using wireless communications. This developed dashboard uses Node-RED and Node-RED-Dashboard to receive the resistance values of up to four contact resistance measurement systems and show them to user's monitor screen. Users can manage multiple measurement data using a single dashboard and easily interface with other devices through the MQTT broker server. Through the experimental results from real data measurements, the relative standard deviation about precision is improved to average 40.37% and maximum 64.73% respectively.

Platinum Transporters and Drug Resistance

  • Choi, Min-Koo;Kim, Dae-Duk
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1067-1073
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    • 2006
  • Cisplatin, a platinum coordinated complex, is a widely used antineoplastic agent for the treatment of metastatic tumors of the testis, metastatic ovarian tumors, lung cancer, advanced bladder cancer and many other solid tumors. The cytotoxic action of the drug is often thought to be associated with its ability to bind DNA to form cisplatin-DNA adducts. The development of resistance to cisplatin during treatment is common and constitutes a major obstacle to the cure of sensitive tumors. Although to understand the clinically relevant mechanisms of resistance, many studies have been aimed at clarifying the biochemical/molecular alterations of cisplatin-resistance cells, these studies did not conclusively identify the basis of cellular resistance to cisplatin. In this review, cisplatin resistance was discussed in terms of the relevant transporters, such as copper transporters (CTRs), organic cation transporters (OCTs) and multi-drug resistance related transporters (MDRs). These transporters seem to be contributed to cisplatin resistance through the reduction of drug accumulation in the cell. Better understanding the mechanism of cisplatin resistance associated with transporters will provide the useful informations for overcoming the cisplatin resistance.

Design of 1-Kb eFuse OTP Memory IP with Reliability Considered

  • Kim, Jeong-Ho;Kim, Du-Hwi;Jin, Liyan;Ha, Pan-Bong;Kim, Young-Hee
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.11 no.2
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    • pp.88-94
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    • 2011
  • In this paper, we design a 1-kb OTP (Onetime programmable) memory IP in consideration of BCD process based EM (Electro-migration) and resistance variations of eFuse. We propose a method of precharging BL to VSS before activation of RWL (Read word-line) and an optimized design of read NMOS transistor to reduce read current through a non-programmed cell. Also, we propose a sensing margin test circuit with a variable pull-up load out of consideration for resistance variations of programmed eFuse. Peak current through the non-programmed eFuse is reduced from 728 ${\mu}A$ to 61 ${\mu}A$ when a simulation is done in the read mode. Furthermore, BL (Bit-line) sensing is possible even if sensed resistance of eFuse has fallen by about 9 $k{\Omega}$ in a wafer read test through a variable pull-up load resistance of BL S/A (Sense amplifier).

A study on the stress distribution and nugget formation in resistance welding process using computer simulation (컴퓨터 시뮬레이션을 이용한 저항용접에 관한 연구)

  • 함원국
    • Journal of Welding and Joining
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    • v.9 no.3
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    • pp.41-51
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    • 1991
  • The thermomechanical coupling phenomena in the resistance welding process is complicated due to interactions of mechanical, thermal and electrical factors. Although experimental investigations of resistance spot welding have been carried out, but there are a few by computer simulation. so the purpose of this research is to decrease the time and cost much required in experimental investigation by carrying out the analysis of the resistance spot welding process through computer simulation based on the finite element method. The tool used in the computer simulation is the commercial ANSYS program package. A two dimensional axisymetric model is used to simulate the resistance spot welding for two stainless steel sheets of equal thickness and parametric study is carried out for variable welding current, workpieces of unequal thickness and dissimilar materials. The results from the computer simulation are in good agreement with the experimental one. Through these results, such items as stress distribution, temperature profiles, thermal expansion and weld nugget formation are predicted. Reliability and applicability of finite element models have been demonstrated to simulate and to analyze the resistance spot welding process.

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Designing method for fire safety of steel box bridge girders

  • Li, Xuyang;Zhang, Gang;Kodur, Venkatesh;He, Shuanhai;Huang, Qiao
    • Steel and Composite Structures
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    • v.38 no.6
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    • pp.657-670
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    • 2021
  • This paper presents a designing method for enhancing fire resistance of steel box bridge girders (closed steel box bridge girder supporting a thin concrete slab) through taking into account such parameters namely; fire severity, type of longitudinal stiffeners (I, L, and T shaped), and number of longitudinal stiffeners. A validated 3-D finite element model, developed through the computer program ANSYS, is utilized to go over the fire response of a typical steel box bridge girder using the transient thermo-structural analysis method. Results from the numerical analysis show that fire severity and type of longitudinal stiffeners welded on bottom flange have significant influence on fire resistance of steel box bridge girders. T shaped longitudinal stiffeners applied on bottom flange can highly prevent collapse of steel box bridge girders towards the end of fire exposure. Increase of longitudinal stiffeners on bottom flange and web can slightly enhance fire resistance of steel box bridge girders. Rate of deflection-based criterion can be reliable to evaluate fire resistance of steel box bridge girders in most fire exposure cases. Thus, T shaped longitudinal stiffeners on bottom flange incorporated into bridge fire-resistance design can significantly enhance fire resistance of steel box bridge girders.

Comparison of chemical resistance properties of anodized film according to anodized sealing treatment method of Al6061 alloy (Al6061 합금의 양극산화 봉공 처리 방법에 따른 양극산화 피막의 내화학 특성 비교)

  • Young Uk Han;Sang Sub Lee;Jun Seok Lee;Gibum Jang;Sung Youl Cho
    • Journal of the Korean institute of surface engineering
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    • v.57 no.3
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    • pp.201-207
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    • 2024
  • This study compared the chemical resistance properties according to various sealing treatment methods for the anode film formed during the anodization process of Al6061 alloy. Al6061 aluminum was used in four different sealing treatment methods: boiling water sealing, lithium sealing, nickel sealing, and pressurized sealing, and each sample was evaluated for corrosion resistance through a 5% HCl bubble test and the microstructure was observed through a scanning electron microscope(SEM). According to the results, corrosion resistance increased as time and temperature increased in all sealing treatment methods. Relatively, corrosion resistance was high in the order of boiling water sealing, lithium sealing, nickel sealing, and pressure sealing, and the best corrosion resistance was found in pressure sealing. These research results can be helpful in selecting a process necessary to improve the efficiency and performance of anodizing process in the industrial field using aluminum alloys.

Identification of Genes Related to Fungicide Resistance in Fusarium fujikuroi

  • Choi, Younghae;Jung, Boknam;Li, Taiying;Lee, Jungkwan
    • Mycobiology
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    • v.45 no.2
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    • pp.101-104
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    • 2017
  • We identified two genes related to fungicide resistance in Fusarium fujikuroi through random mutagenesis. Targeted gene deletions showed that survival factor 1 deletion resulted in higher sensitivity to fungicides, while deletion of the gene encoding F-box/WD-repeat protein increased resistance, suggesting that the genes affect fungicide resistance in different ways.

Improvement of Out-of-Plane Impact Damage Resistance of CFRP Due to Through-the-Thickness Stitching

  • Yoshimura, Akinori;Nakao, Tomoaki;Takeda, Nobuo
    • Advanced Composite Materials
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    • v.18 no.2
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    • pp.121-134
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    • 2009
  • The present study investigated, both experimentally and numerically, the improvement of low-velocity impact damage resistance of carbon fiber reinforced plastic (CFRP) laminates due to through-the-thickness stitching. First, we conducted drop-weight impact tests for stitched and unstitched laminates. The results of damage inspection confirmed that stitching did improve the impact damage resistance, and revealed that the improvement effect became greater as the impact energy increased. Moreover, the stitching affected the through-the-thickness damage distribution. Next, we performed FEM analysis and calculated the energy release rate of the delamination crack using the virtual crack closure technique (VCCT). The numerical results revealed that the stitching affected the through-the-thickness damage distribution because the stitch threads had a marked effect on decreasing both the modes I and II energy release rate around the bottom of the laminate. Comparison of the results for models that contained delaminations of various sizes revealed that the energy release rate became lower as delamination size increased; therefore the stitching improved the impact resistance more effectively when the impact energy was higher.

Nail Withdrawal Resistance and Embedding Strength of Structural Wood Panels with Water Absorption (수분의 흡수에 따른 구조용 목질판넬의 인발 및 함입성능)

  • 오세창
    • Journal of the Korea Furniture Society
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    • v.10 no.2
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    • pp.1-8
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    • 1999
  • The use of structural wood based panels like plywood, OSB in many applications involves the use of nails, and data on the performance of panel-nail connection are needed for design and comparative purpose. This study was carried out to develop basic information on nail performance(withdrawal, embedding, nailhead push through) with water absorption in plywood and OSB. In withdrawal resistance test, initial stiffness of plywood performed better than OSB in 24hr soaked condition. The soaked condition reduced average nail withdrawal resistance value about 46% (12d mail), 53%(8d nail) in OSB, 17%(12d mail), 24%(8d mail) in plywood. The nail embedding strength of plywood also performed better than that of OSB and retention value(wet strength/dry strength) yielded similar in each nail types. The nail head push through capacity of OSB was higher than that of plywood in dry condition, but equal or lower in soaked condition. Therefore, critical consideration about structural panels is required in moist applications. The average values of nail withdrawal, nail embedding strength and nail head push through resistance of tested materials meet the minimum requirement of various specification and standards.

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A Study on Wear Characteristics of Machine Structural Steel by Surface Modification (표면개질에 의한 기계구조용강의 마멸특성에 관한 연구)

  • Park Heung-Sik;Woo Kyu-Sung
    • Tribology and Lubricants
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    • v.22 no.2
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    • pp.73-78
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    • 2006
  • The surface modification of automobile parts is of great technological importance for the improvement of corrosion resistance, wear resistance, fatigue strength and so on. Recently, research on the development of the technology of surface modification substituting 6-balance chrome process has progressively been achieved in automobile parts. Although the innovation technology for the improvement of the corrosion-resisting and wear resistant properties through post oxidation after nitrocarburising process had attracted a great attention. For this, anodically potentiodynamic polarisation testing was carried out to corrosion resistance and friction and wear experiment according to applied load and sliding distance was carried out to evaluate the wear resistance of machine structural steel with nitrocarburising and non-nitrocarburising SM45C. The presumed wear volume was calculated with the image processing far evaluation of wear resistance of two materials. The results show that the nitrocarburising had a distinguished corrosion resistance and wear resistance than non-nitrocarburising.