• Title/Summary/Keyword: accelerating

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Fast-Curing of Phenol·Formaldehyde Resin Adhesives for Plywood (합판용 페놀수지 접착제의 속경화)

  • Roh, Jeang-Kwan
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.33-39
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    • 1995
  • To accelerate the cure of phenolic resin adhesives for plywood, the complexation with melamine resin and the addition of cure-accelerating agents were discussed. The hot-pressing temperature and time of phenol resin could be decreased by complexation with melamine resin. but the wet glue-joints strength of phenol melamine resin was lower than that of ordinary phenol resin in case of plywood using spruce veneer at core layer. Among the tested cure-accelerating agents. the sodium carbonate showed the greatest effect on shortening gelation time of phenolic resin. In addition, in the manufacturing scale test, the hot-pressing time of phenol resin with the addition of 5 parts sodium carbonate could be shortened about 20% compared with ordinary phenol resin which had same glue-joints properties.

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A technology State of Accelerating Degradation and Life Estimation on the Traction Motor for Railway Rolling Stock (철도차량 견인전동기의 가속열화수명평가 기술현황)

  • Wang, Jong-Bae;Kim, Ki-Jun;Choi, Young-Chan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.10a
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    • pp.25-28
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    • 2000
  • In this paper, the technology for accelerating degradation & life estimation on the traction motor was introduced with the stator form-winding sample coils of the 200 Class insulation system The accelerative degradation was performed in 10 cycles, which were composed of thermal stress, fast rising surge voltage, vibration, water immersion and overvoltage applying. After aging of 10 cycles, condition diagnosis test such as insulation resistance & polarization index, capacitance & dielectric loss and partial discharge properties were investigated in the temperature range of $20{\sim}160^{\circ}C$. Relationship between degradation conditions and diagnosis results were analyzed to find an dominative degradation factor at the end-life point

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Studies on the Treatment of Weight Loss of PET Fibers by Alkyldimethylbenzylammonium Chlorides (알킬디메틸벤질암모늄 클로라이드에 의한 PET섬유의 감량가공에 관한 연구)

  • Park, Hong-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.10 no.2
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    • pp.29-33
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    • 1993
  • n-Octyldimethylbenzylammonium chloride, dodecyldimethylbenzylammonium chloride, and octadecyldimethylbenzylammonium chloride were synthesized to be used as the accelerating weight loss agent. These synthesized compounds were used for the weight loss treatment of PET textile with sodium hydroxide. From the treatments, it was found that the lower carbon number of high alkyl group existed in quaternary ammonium salts, the better effect of weight loss was acquired. The proper concentration of accelerating weight loss agent was $8{\sim}10g/l$, the proper treatment time was $60{\sim}90$ minutes, the proper treating bath ratio was 1 : 50. It is proved that n-octyldimethylbenzylammonium chloride and dodecyldimethylbenzylammonium chloride are good accelerating weight loss agent.

Study on Setting Time Measuring Methods of a Cement Accelerating Admixture (시멘트 급결제의 응결시간 측정방법에 대한 연구)

  • Heo Gweon;Choi Hong Shik;Lee Si Woo;Yi Seong Tae;Jung Yi Seok;Kwak Hong Shin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.317-320
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    • 2004
  • The setting time is very important factor affecting the quality of tunnel lining and reinforcement of sloped slope etc. Currently, however, the quality criteria of accelerating admixture to improve it is not established well. In this study, evaluation on setting time measuring methods of a cement accelerating admixture was performed. Six types of measuring methods were checked and a proper measuring method of the admixture were proposed as fellows: (1) the temperature of materials used shall be controlled exactly and (2) to evaluate the properties of it, an admixture usage of $5\%$ (ratio of cement weight) is recommended.

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A Causal Map Analysis on the Accelerating Policies for Universities to Adopt NCS-based Educational Programs (인과지도를 활용한 4년제 대학 NCS 도입 활성화 방안 연구)

  • Juhn, Jaeho
    • Korean System Dynamics Review
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    • v.17 no.3
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    • pp.5-29
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    • 2016
  • The Korean government has constructed the national competency standards (NCS) rapidly since the year 2013. Also, it has pushed 2-year colleges to adopt NCS-based educational programs and public institutions to hire new employees by using NCS. It expects that NCS will deplete the mismatch between the requirements of employers and the abilities of employees. The purpose of this paper is to find correct accelerating policies for universities to adopt NCS-based educational programs. In order to achieve the purpose, primarily the government policies for NCS were analyzed by using causal map. And then, three accelerating policy recommendations for universities to adopt NCS were drawn by using the results of causal map analysis. The three recommendations are as follows. First, the quality of NCS should be kept highly. Secondly, the NCS-based hiring system of public institutions should also be standardized. Finally, the authorities of universities should be guaranted whenever they make educational programs.

Study on Long-term Deterioration Properties of Porcelain Insulators with Aluminous System (알루미나계 자기애자의 장기 피로특성에 관한 연구)

  • Han, Se-Won;Cho, Han-Goo;Lee, Dong-Il;Cho, In-Hyuk
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.562-563
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    • 2005
  • In case of aged porcelain, the failure in basic performance tests happened in cool-heat tests. Based on this characteristic, we studied the method predicting failure phenomena through more severe accelerated cool-heat ageing and accelerating thermal mechanical performance tests. Test results indicated that the thermal stress by temperature gradient was more severe parameter than thermal stress by quenching cycles within a category of standard or accelerating methods. And there is no the deterioration of statistic strength, but the deterioration of strength according to accelerating tests is serious.

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Study on Thermal Stress of Porcelain Insulator for T/L (송전용 자기애자의 열충격 특성 연구)

  • Han, Se-Won;Cho, Han-Goo;Choi, In-Hyuk;Lee, Dong-Ill
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.208-209
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    • 2006
  • This study presents the thermal stress characteristics of TL porcelain insulators(healthy and ageing) by the accelerating thermal mechanical ageing test with forced temperature gradient. The test temperature gradient is $95^{\circ}C(-35{\sim}60^{\circ}C)$, it was focused to high temperature thermal stress as compared with IEC 60575 standard. There was no a discrimination in the case of healthy aluminous porcelain insulators, dissimilarly in crystoballite insulators according to this test method. It was indicated that the long tenn reliability by thermal stress was conformed reasonably through the conventional accelerating ageing test methods.

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A Study on the Development of Driving Simulator for Improvement of Unmanned Vehicle Remote Control (무인차량 원격주행제어 신뢰성 향상을 위한 통합 시뮬레이터 구축에 관한 연구)

  • Kang, Tae-Wan;Park, Ki-Hong;Kim, Joon-Won;Kim, Jae-Gwan;Park, Hyun-Chul;Kang, Chang-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.86-94
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    • 2019
  • This paper describes the development of unmanned vehicle remote control system which is configured with steering and accelerating/braking hardware to improve the sense of reality and safety of control. Generally, in these case of the remote control system, a joystick-type device is used for steering and accelerating/braking control of unmanned vehicle in most cases. Other systems have been developing using simple steering wheel, but there is no function of that feedback the feeling of driving situation to users and it mostly doesn't include the accelerating/braking control hardware. The technology of feedback means that a reproducing the feeling of current driving situation through steering and accelerating/braking hardware when driving a vehicle in person. In addition to studying feedback technologies that reduce unfamiliarity in remote control of unmanned vehicles, it is necessary to develop the remote control system with hardware that can improve sense of reality. Therefore, in this study, the reliable remote control system is developed and required system specification is defined for applying force-feedback haptic control technology developed through previous research. The system consists of a steering-wheel module similar to a normal vehicle and an accelerating/braking pedal module with actuators to operate by feedback commands. In addition, the software environment configured by CAN communication to send feedback commands to each modules. To verify the reliability of the remote control system, the force-feedback haptic control algorithms developed through previous research were applied, to assess the behavior of the algorithms in each situation.

Strength Characteristics of 3D Printing Concrete for Exterior materials using Accelerating agent (급결제를 사용한 외장재용 3D 프린팅 콘크리트의 강도 특성)

  • Seo, Dae-Seuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.267-272
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    • 2021
  • In this study, the output results of 3D printed exterior materials for application to buildings of various shapes are output tests using test specimens, in which 3D printing concrete is cast in a mold and accelerating agents are used to ensure stackability. The unit weight and strength characteristics of the body were analyzed. Compared to the unit weight of concrete placed in the mold, the unit weight of 3D printing concrete using accelerating agents tends to decrease by approximately 3.5% to 5.0%, and the compressive strength is the compressive strength of the concrete placed in the mold. In comparison, the compression strength of the output by 3D printing tended to decrease by approximately 36% to 46%. In the flexural strength, the compressive strength of the output through 3D printing decreased by approximately 36% to 46% compared to the compressive strength of concrete placed in the mold. The impact on the strength characteristics of 3D printed concrete using accelerating agents tended to decrease by approximately 2.0 to 5.8%. Therefore, 3D printing output accelerating agents can be used.