• Title/Summary/Keyword: W-W Test

Search Result 4,648, Processing Time 0.035 seconds

Development of an Inert Gas Water Mist System -A Numerical Study on Ventilation of the Fire Test Room- (불활성가스 미분무소화설비의 개발 -화재시험실의 급기에 관한 수치연구-)

  • Park, Woe-Chul;Jeong, Lee-Gyu
    • Journal of the Korean Institute of Gas
    • /
    • v.12 no.1
    • /
    • pp.25-30
    • /
    • 2008
  • A Numerical study was carried out for a propane gas pool fire in the fire test room of $2.5m{\times}2.0m{\times}2.5m$ for testing a inert gas water mist system, to investigate a possible under-ventilation in the fire test room. For the fire sizes of 60 kW and 120 kW, changes in the temperature and CO concentration with and without a window were investigated. It was confirmed that the influence of the window on the distributions of temperature and CO concentration was small in the two fire sizes, and hence the under-ventilation was not occurred in the room.

  • PDF

Measurements of In-situ Thermal Conductivity of Closed Type Ground Heat Exchanger in Korea (국내의 주요 지역에서 밀폐형 열교환기의 열전도도 측정)

  • Jung, Kye-Hoon;Lim, Hyo-Jae;Han, Ji-Won;Park, Kyung-Woo
    • Proceedings of the KSME Conference
    • /
    • 2007.05b
    • /
    • pp.3401-3406
    • /
    • 2007
  • This study was performed to acquire the reliable in-situ thermal conductivity of closed type ground heat exchanger used in ground source heat pump. We selected four sites(Cheonan, Daejeon, Daegu, Gwangju) which are central area of South Korea. Test results show that the effective thermal conductivities are 2.33 W/m$^{\circ}C$, 2.50 W/m$^{\circ}C$, 2.75 W/m$^{\circ}C$ and 2.86 W/m$^{\circ}C$. From this data, we can see that thermal conductivity varies about the range of 23% with the sites. Also, thermal conductivity increases up to 20% by changing grouting material from low salica sand to high one.

  • PDF

Genetical and Biochemical Studies on White Egg Strains of Silkworm, Bombyx mori (누에 백란 계통의 유전적 특성구명을 위한 유전.생화적 연구)

  • 이은정;임봉학
    • Journal of Sericultural and Entomological Science
    • /
    • v.39 no.2
    • /
    • pp.134-139
    • /
    • 1997
  • To elucidate genetical and biochemical characters of the white egg strains preserved in National Sericultural and Entomology Research Institute(NSERI), RDA of Korea, the genetic segregation ratios in egg colours were investigated by crossing test, and egg pigment precursors were also analyzed by paper chromatography and UV-spectrophotometer scanning. The result obtained by crossing test between the white egg strains and normal one illustrated that the most of white egg strains showed typical segregation ratio of white egg-2(w-2), while maternal inheritance which can be seen in white egg-1(w-1) was not found in any white egg strains. Paper chromatographic analysis showed that egg extracts of all the white egg strains contained 3OH-kynurenine, while kynurenine which is known to existed in white egg-1(w-1) could not be detected at all. From the results of these experiments, it was found that all the white egg strains preserved in NSERI were classified as the white egg-2(w-2) strain.

  • PDF

Characteristics of cold startup in automotive PEMFC (차량용 고분자전해질 연료전지의 냉시동 특성)

  • Ko, Jae-Jun;Kwon, Soon-Kill;Kum, Young-Bum;Lee, Jong-Hyun
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2007.11a
    • /
    • pp.137-141
    • /
    • 2007
  • The startup behaviour of PEM fuel cells at subfreeze zero is one of the most challenging tasks to be solved before PEM fuel cell vehicle is commercialized. Automotive companies are trying to increase cold statup capability of fuel cell. In this study, we found out the design factor of the stack to increase cold startup capability using 4kW stack and then cold startup test was performed at the various shutdown condition and the various current. In order to test the cold startup possibility and capability in vehicle, we installed 80kW stack in the vehicle and this 80kW fuel cell vehicle was housed in an environmental chamber to investigate the characteristics of cold startup and driving. We found that it is possible for fuel cell vehicle with 80kW stack to self-heated cold startup and drive at $-15^{\circ}C$.

  • PDF

Quality Characteristics of Snack with Added Dongchimi Powder (동치미 분말을 이용한 스낵의 품질 특성)

  • Choi, Jin Joo;Park, Yoo Ri;Chung, Chang-Ho
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.24 no.6
    • /
    • pp.819-826
    • /
    • 2014
  • Consumer's demand for higher dietary fiber and lower fat in processed foods are increasing. This study developed a low fat and high dietary fiber snack using egg whites and dry fermented radish powder obtained from Dongchimi fermentation. Quality characteristics, such as hardness, color, fat content and total dietary fiber, of the developed snack were conducted along with a hedonic test. As the amount of the fermented powder increased in the formulation, water content and snack hardness decreased. Up to 14.5% radish powder was added (or 9.54% dietary fiber; dry weight, w/w) to the formulation, and hedonic test found snack containing 4.8% (w/w) powder showed the highest scores for overall acceptability.

Durability Prediction of Door W/H System Using FEM Analysis (전면 도어 와이어하니스 시스템의 내구 수명 예측에 관한 연구)

  • Kim, Byeong Sam;Lim, Kwangkyu
    • Journal of Auto-vehicle Safety Association
    • /
    • v.5 no.2
    • /
    • pp.51-56
    • /
    • 2013
  • In vehicle's door wiring harness (W/H) system is more toward to arrange a passenger compartment than a hinge and a weatherstrip. An opening/closing member of a vehicle is attached to a vehicle by a hinge in a manner enabling easy opening and closing of the opening/closing member. Such members include doors, such as side-doors and rear doors, and other opening/closing members, such as trunk lids. This article gives some insight into the dimensioning process, with special focus on large deflection analysis of wiring harness(W/H) in vehicle's door structures for durability problem. The Finite elements analysis for door wiring harness(W/H) is used for residual stresses and dimensional stability with bending flexible. Durability test data for slam test specimens were compared with the numerical predicted fatigue life for verification. The final testing of the component combines the effects of these microstructural features with the complex stress state arising from the combined service loading and residual stresses.

Electrochemical Behavior and Biocompatibility of Co-Cr Dental Alloys

  • Kang, Jung-In;Yoon, Jun-Bin;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2015.05a
    • /
    • pp.107-107
    • /
    • 2015
  • In order to investigate electrochemical behavior and biocompatibility of Co-Cr dental alloy by electrochemical corrosion test and MTT assay, the xCo-25Cr-yW-zNi alloys were used in this study. Samples of Co-Cr-W-Ni alloys were manufactured using arc melting furnace. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. Corrosion resistance increased slightly as cobalt (Co) content increased. And bioactivity was concerned with nickel (Ni) and tungsten (W). Biocompatibility of Co-Cr alloy depended on Ni and W contents.

  • PDF

Fabrication and test of MRI superconducting magnet with 20cm room temperature bore (20cm 상온 보아를 갖는 MRI용 초전도 마그네트의 제작 및 평가)

  • Jin, H.B.;Oh, B.H.;Cho, J.W.;Oh, S.S.;Kwon, Y.G.;Ha, D.W.;Lee, E.Y.;Ryu, K.W.;Ryu, K.S.;Nah, W.S.;Kim, S.R.;Han, I.Y.
    • Proceedings of the KIEE Conference
    • /
    • 1995.07a
    • /
    • pp.153-155
    • /
    • 1995
  • We fabricated superconducting magnet for MRI and tested it using automatic field mapping system. This magnet has 20cm diameter of room temperature bore for the sample access. In this paper, the fabrication of MRI magnet system and the test results of field homogeneity are described.

  • PDF

Probability Models of W-CDMA Signals in Realistic Wideband Multipath Channels (광대역 다중경로 실측채널에서 W-CDMA 수신 신호의 화률 모델)

  • 오동진;이주석;이귀상;김철성
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.27 no.4B
    • /
    • pp.308-315
    • /
    • 2002
  • This paper proposes new probability models for wideband code division multiple access (W-CDMA) signals. The performance of a W-CDMA system is evaluated by calculating the average bit error rate(BER) which is derived from the probability distribution of the W-CDMA receiver output. If a probability model of the receiver output is available, the performance evaluation becomes much simpler and it enables diverse analyses of the system for channel coding and other purposes. In this paper, probability distributions of W-CDMA signals, more specifically those of the receiver output, are represented as Rayleigh and noncentral chi distribution, considering various bandwidths and channel environments. The adequacy of a probability model is verified by chi-square test of 1% significance level. The BER of the system obtained from the simulation results is compared to that obtained from the probability model to demonstrate the usefulness of the proposed models.

An Influence of W/B and Curing Temperature on Autogenous Expansion of MgO Concrete (물-결합재비(W/B)와 양생온도가 MgO혼입 콘크리트의 자기팽창 변화에 미치는 영향)

  • Jang, Bong-Seok;Kwon, Yong-Gil;Lee, Kwang-Myong;Choi, Seul-Woo
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2010.05a
    • /
    • pp.293-294
    • /
    • 2010
  • In this study, it was analyzed that autogenous expansion of MgO concrete was affected by W/B and curing temperature. Autogenous expansion test was performed for MgO concrete, which is mixed MgO of 0%, 5% of cement weight. With autogenous expansion based on long-term time variation was measured, it was observed an influence with W/B and curing temperature.

  • PDF