• Title/Summary/Keyword: expansion pressure

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A Study on the Color of Medical Robot Bed from the Universal Design Perspective -A Case Study on the Universal Color Design of Ninebell Corporation's Medical Robot Bed- (유니버셜 디자인 관점에서 본 의료 로봇 침대 색채에 관한 연구 -(주)나인벨의 의료용 로봇 침대의 유니버셜 디자인 색채 사례를 중심으로-)

  • Cho, Hyun Kyung
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.4
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    • pp.203-208
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    • 2019
  • Medical color graphic research will serve as the basis for globally expanding and disseminating the design quality of the company's products through the era of production of medical robots. This study was based on technologies and contents suitable for the era of medical robot bed expansion, universal medical color application, ergonomic color, etc. In addition, the medical bed robot's color research direction was presented from the perspective of universal design. Accordingly, a universal color design was proposed, taking the functions of a medical robot under development by a domestic company as an example. The characteristics of this robot bed can be divided into three types of functions: first, treatment characteristics for prevention of pressure ulcers with curative, second, automatic seat exchange with cleanliness for medical environment, and third, Convenient, which can implement patient transport. The main idea is to present a combination of functional colors appropriate for this. The resulting color analysis and universal color design techniques could be a useful methodology for illustrating the appearance and function of a modern medical robot bed.

A Preliminary Configuration Design of Methane/Oxygen Bipropellant Small-Rocket-Engine through Theoretical Performance Analysis (이론성능해석에 의한 메탄/산소 이원추진제 소형로켓엔진의 예비형상설계)

  • Bae, Seong Hun;Jung, Hun;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.3
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    • pp.47-53
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    • 2015
  • Design parameters required for Methane/oxygen bipropellant small-rocket-engine were derived through a theoretical performance analysis. The theoretical performance of the rocket engine was analyzed by using CEA and optimal propellant mixture ratio, characteristic length, and optimal expansion ratio were calculated by assuming chemical equilibrium. A coaxial-type swirl injector was chosen because of its outstanding atomization performance and high combustion efficiency compared to other types of injector and also a bell nozzle with 80% of its full length was designed. The rocket engine configuration with 1.72 MPa of chamber pressure, 0.18 kg/s in total propellant mass flow, and O/F ratio of 2.7 was proposed as a ground-firing test model.

A Study on Analytical Approach for Performance Evaluation of Pyrotechnically Actuated Device (파이로작동기구 성능평가를 위한 해석모델 연구)

  • Choi, Joo-Ho;Sung, Hong-Gye;Kim, Jun-Sik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.63-64
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    • 2012
  • A pyrotechnic actuated device (PAD) is a component that delivers high power in remote environments by combustion of a self-contained energy source. Historically, the design of these devices has been largely empirical and considered to be an art. In this study, an overview for developing an analytical model is introduced that efficiently evaluates performance of PAD. The model is integrated by three parts of different disciplines that are coupled in sequence with each other. First is the solid explosive burning to form product gas within an actuator and transport to an expansion chamber. Second is the insertion of initially tapered piston into a small hole by gas pressure in the chamber. Third is the shear cutting of the diaphragm from the piston to enable gas flow into the conduit. Some results of preliminary study for each of three parts are introduced in the presentation.

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Design of Excess Flow Device for Automotive Cylinder Valve Based on Finite Element Analysis (유한요소 해석을 이용한 자동차 압력 용기 밸브용 과류 방지 장치의 설계)

  • Lee, Hyo-Ryeol;Kwon, Dae-Hwan;Shin, Jin-Oh
    • Journal of the Korean Institute of Gas
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    • v.25 no.5
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    • pp.19-29
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    • 2021
  • Due to the climate changing, the world's countries are tightening regulations on CO2 and air pollutants emission to solve them. In addition, eco friendly vehicles is increasing to replace automobiles in internal combustion engine. Recently, the government is supporting the expansion of hydrogen refueling infrastructure and localization of core equipment in refueling facilities according to the hydrogen economy road map. In this study, design of the Excess flow limiting device in FCEV cylinder valve using by finite element analysis and performed performance tests on prototype. Major test results as hydrostatic strength, continued operation, operation, pressure impulse, leakage showed that the excess flow limiting device meets the performance requirements according to ISO 12619-2 and ISO 12619-11.

A Comparative Study on the Interior Design of Korean-Chinese Coffee Shop - Focusing on the Starbucks (한·중 커피전문점의 실내 공간 환경 디자인 비교 연구 - 스타벅스를 중심으로)

  • Zhou, LIng;Cho, joung-hyung
    • Journal of the Korea Convergence Society
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    • v.10 no.1
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    • pp.123-132
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    • 2019
  • As the rapid pace of modern society, people's daily life is becoming tenser and busier. We need a place to relax and to release our pressure. Coffee shops therefor become one of our best choice. With the strengthening of the expansion of the localized Starbucks coffee shop, it becomes extremely urgent for other coffee shops to enhance the space environment design to become outstanding in the coffee shop market. This paper researches and compares the indoor environment design of Starbucks coffee shops in four cities in China, namely Shanghai, Suzhou, Shenzhen and Beijing and four cities in Korea, namely Busan, Seoul, Seoul and Jeju. By comparing the design characteristics and the style of the interior environment of Korea-China coffee shops, we analyze the various elements of space design and summarize the differences in the environmental design of Korea-China Starbucks coffee shops. Moreover, we propose the strategic direction for the future design and the future development of coffee shops. The survey results show that the indoor environment design of Starbucks coffee brand mainly highlights the regional cultural characteristics. Starbucks shops utilize the fashion culture elements based on the local economic and cultural characteristics, aiming at creating a characteristic coffee brand culture and promoting the vigorous development of the coffee market.

Analysis of Shear Behavior and Fracture Characteristics of Plywood in Cryogenic Environment (극저온 환경 하 플라이우드의 전단 거동 및 파손 특성 분석)

  • Son, Young-Moo;Kim, Jeong-Dae;Oh, Hoon-Kyu;Kim, Yong-Tai;Park, Seong-Bo;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.33 no.5
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    • pp.394-399
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    • 2019
  • Plywood is a laminated wood material where alternating layers are perpendicular to each other. It is used in a liquefied natural gas (LNG) carrier for an insulation system because it has excellent durability, a light weight, and high stiffness. An LNG cargo containment system (LNG CCS) is subjected to loads from gravity, sloshing impact, hydrostatic pressure, and thermal expansion. Shear forces are applied to an LNG CCS locally by these loads. For these reasons, the materials in an LNG CCS must have good mechanical performance. This study evaluated the shear behavior of plywood. This evaluation was conducted from room temperature ($25^{\circ}C$) to cryogenic temperature ($-163^{\circ}C$), which is the actual operating environment of an LNG storage tank. Based on the plywood used in an LNG storage tank, a shear test was conducted on specimens with thicknesses of 9 mm and 12 mm. Analyses were performed on how the temperature and thickness of the plywood affected the shear strength. Regardless of the thickness, the strength increased as the temperature decreased. The 9 mm thick plywood had greater strength than the 12 mm thick specimen, and this tendency became clearer as the temperature decreased.

A Numerical Analysis on Performance of Parallel Type Ejector for High Altitude Simulation (고공 환경 모사를 위한 병렬형 이젝터 구성에 따른 특성 연구)

  • Shin, Donghae;Yu, Isang;Shin, Minku;Oh, Jeonghwa;Ko, Youngsung;Kim, Sunjin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.1
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    • pp.52-60
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    • 2019
  • In this study, the performance and structure of a parallel ejector comprised of multiple single ejectors were confirmed through numerical analysis. The same design variables (mass suction ratio, compression ratio, and expansion ratio) relevant to the performance of a single ejector were considered in the design of the parallel ejector. Analytical results showed that there was no significant difference in the performance of either system related to the operating mass suction ratio; however, the systemsize was significantly reduced. In addition, it was confirmed that when ejectors of the same performance capacity are arranged in parallel, the combined mass suction ratio is lower than that of the single ejector, allowing a lower pressure to be realized. The results of the analysis indicated that the parallel ejector's performance is not significantly different from that of any single ejector, but confirmed that the parallel ejector can offer a configurationdependent advantage in size and operation.

Three-dimensional numerical simulation of hydrogen-induced multi-field coupling behavior in cracked zircaloy cladding tubes

  • Xia, Zhongjia;Wang, Bingzhong;Zhang, Jingyu;Ding, Shurong;Chen, Liang;Pang, Hua;Song, Xiaoming
    • Nuclear Engineering and Technology
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    • v.51 no.1
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    • pp.238-248
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    • 2019
  • In the high-temperature and high-pressure irradiation environments, the multi-field coupling processes of hydrogen diffusion, hydride precipitation and mechanical deformation in Zircaloy cladding tubes occur. To simulate this hydrogen-induced complex behavior, a multi-field coupling method is developed, with the irradiation hardening effects and hydride-precipitation-induced expansion and hardening effects involved in the mechanical constitutive relation. The out-pile tests for a cracked cladding tube after irradiation are simulated, and the numerical results of the multi-fields at different temperatures are obtained and analyzed. The results indicate that: (1) the hydrostatic stress gradient is the fundamental factor to activate the hydrogen-induced multi-field coupling behavior excluding the temperature gradient; (2) in the local crack-tip region, hydrides will precipitate faster at the considered higher temperatures, which can be fundamentally attributed to the sensitivity of TSSP and hydrogen diffusion coefficient to temperature. The mechanism is partly explained for the enlarged velocity values of delayed hydride cracking (DHC) at high temperatures before crack arrest. This work lays a foundation for the future research on DHC.

The Analysis of Thermal Conductivity and Basic Quality Performances of Decoration Wood-based Flooring Board Laminated with PVC Surface Decoration Materials (PVC 표면치장재를 적층한 치장목질마루판의 열특성 및 기초 품질성능 분석)

  • Park, Cheul-Woo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.1
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    • pp.53-60
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    • 2018
  • For test on flooring board laminated with PVC decoration materials in order to replace the current surface materials such as HPL in decoration wood-based flooring board. the Results of comparison and analysis are as follows: For thermal conductivity, flooring board decorated with PVC did not show huge differences when temperature was rising and lowering compared to the flooring materials laminated with the existing HPL surface materials. It seems the most meaningful results for using it as indoor flooring materials. That is, in Korea where there is the culture focusing on ondol heating, use amount of heat energy and efficiency of flooring materials are very important and sensitive issues, involving immediately with household economy of final consumers, and it might be a criteria to judge basic performances required as flooring materials. As a result of the analysis on mandatory durability test items such as abrasion resistance, absorption width expansion rate, impact resistance, surface hardness, and impact absorption for flooring materials, compared to flooring board laminated with general HPL surface decoration materials, decoration wood-based flooring board laminated with PVC surface decoration materials which is higher abrasion resistance with smaller transformation and has better durability and impact absorption of the surface, is available for actual application as indoor flooring board, and for replacing surface decoration materials impregnated with heat-hardened resion such as HPL.

Evaluation of Structural Safety and Leak Test for Hydrogen Fuel Cell-Based Truck Storage Systems (수소트럭 수소저장시스템에 대한 구조안전성 및 기밀성능평가)

  • Kim, Da-Eun;Yeom, Ji-Woong;Choi, Sung-Joon;Kim, Young-Kyu;Cho, Sung-Min
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.11
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    • pp.1-7
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    • 2020
  • Recently, hydrogen has gained considerable attention as an eco-friendly fuel, which helps in reducing carbon dioxide content. Specifically, there is a growing interest in vehicles powered by a hydrogen fuel cell, which is spotlighted as an environmental-friendly alternative. A hydrogen transport system, fuel cell system, fuel supply system, power management system, and hydrogen storage system are key parts of a hydrogen fuel cell truck. In this study, a hydrogen storage system is built and analyzed. The expansion length of the storage vessel at maximum operating pressure (87.5 MPa) was calculated with ABAQUS, and then the optimized system was designed and built. The leak and bubble tests were performed on the built storage system. The leakage of the system was measured to be under 5 cc/hr. Hence, it can be used as a research test for the safety evaluation of leading systems of hydrogen fuel-powered commercial vehicles.