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A Study on Advanced Small Punch Test for Evaluation of Fracture Strength in Heat Resisting Stell Weldment (내열강 용접부의 파괴강도 평가를 위한 Advanced Small Punch 시험에 관한 연구)

  • 이동환;이송인;권일현;유효선
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.99-99
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    • 2002
  • In order to evaluate the proper fracture strength of microstructures in a steel weldment, smaller size loading ball than used for a conventional small punch(CSP) testing is required due to regional limitation on constitutive structures. In this study, the minimized loading ball(φ 1.5mm) and bore diameter of lower die(φ 3mm) were designed for an advanced small punch(ASP) test. The results obtained from the ASP test were compared with those from a CSP testing for a X20CrMoV121 steel weldment. It was found that the ASP test clearly showed the microstructural dependance on fracture strength and ductile-brittle transition behavior of the weldment. In the ASP test, especially, the cracks tend to initiate for various directions within hemispherical indentation region of an objective structure in SP test. This indicates that the evaluation of more proper fracture strength for F.L+CGHAZ, FGHAZ and ICHAZ can be performed by means of the ASP test in a steel weldment.

Two new generic records in the orchid flora of Myanmar

  • KANG, Dae-Hyun;CHO, Seong-Hyun;ONG, Homervergel G.;LING, Shein Man;KYAW, Naing Oo;KIM, Young-Dong;KURZWEIL, Hubert
    • Korean Journal of Plant Taxonomy
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    • v.49 no.1
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    • pp.96-99
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    • 2019
  • The species diversity of Orchidaceae is believed to be extremely high in Myanmar. Like in other plant groups, little basic inventory work has been done thus far. During floristic surveys conducted in Popa Mountain Park (Mandalay Region), Natma Taung National Park (Chin State), and in the Ywangan area (southwestern Shan State), we encountered two interesting orchid species which were determined to be new generic records in the flora of Myanmar. Thuniopsis cleistogama was previously considered endemic to Yunnan Province (China) and was only known from the type locality. However, here the species is newly reported from two localities in central and western Myanmar. Disperis neilgherrensis is known from several widely scattered localities in tropical and subtropical Asia. This tiny orchid species was discovered in the Ywangan area in the southwestern area of the Shan State of Myanmar. These two species will be valuable additions to the updated checklist of the orchids of Myanmar.

Determination of Fission Products in Simulated Nuclear Spent Fuels by Cation.Anion Exchange Chromatography and Inductively Coupled Plasma Atomic Emission Spectrometry (양.음이온교환 크로마토그래피와 유도결합플라스마 원자방출분광법을 이용한 모의 사용후핵연료 중 핵분열생성물 분석)

  • Choi, Kwang Soon;Sohn, Se Chul;Pyo, Hyung Yeol;Suh, Moo Yul;Kim, Do Yang;Park, Yang Soon;Jee, Kwang Yong
    • Analytical Science and Technology
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    • v.13 no.4
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    • pp.446-452
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    • 2000
  • The simulated nuclear spent fuel (SIMFUEL) containing the platinum group elements which will not be dissolved in a nitric acid was completely dissolved with a acid digestion bomb. The metallic elements separated in the SIMFUEL were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). Because the peaks of metallic elements were spectrally interfered by uranium spectrum, uranium and metallic elements were separated by cation exchange resin for Mo, Pd, Rh and Ru and by anion exchange resin for Ba, Ce, La, Nd, Rh, Sr, Y and Zr, respectively. The recovery of Mo, Pd, Rh and Ru after separation by cation exchange chromatography found to be 99-103% and anion exchange separation showed 96.5-107% of recovery except Y with the simulated solution whose concentration was similar to the spent nuclear fuel. The relative standard deviation of this method showed 1.3-6.7% in the SIMFUEL whose concentrations of metallic elements were between several $10^2-10^3$ppm.

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Hydrogen production by plasma pyrolysis-gasification of waste (폐기물의 플라즈마 열분해-가스화에 의한 수소생산)

  • Lee, Jin-Ho;Kim, Young-Suk;Do, Chul-Jin;Hwang, Soon-Mo;Jeong, Seong-Jae
    • New & Renewable Energy
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    • v.3 no.4
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    • pp.77-89
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    • 2007
  • 폐기물의 플라즈마를 이용한 열분해-가스화-용융 처리공정은 청정연료 형태로 정화된 합성가스를 얻을 수 있고, 이 합성가스를 WGS 반응과 PSA 공법을 이용하면 고순도 수소로의 전환 및 회수가 가능하다. (주)애드플라텍에서는 자체 보유하고 있는 3톤/일급 플라즈마 폐기물 처리설비와 수소 정제/회수시스템을 연계하여, 페기물로부터 고순도 수소 생산($20Nm^3/h$이상)을 위한 플라즈마 폐기물 처리 추소 생산 통합시스템 개발을 진행하고 있다. 합성가스 내 질소 농도를 낮추기 위해 산소를 매질로 하는 100kw급 산소 플라즈마 토치를 제작하였다. 수소 정제/회수 시스템은 폐기물의 플라즈마 처리 후의 합성가스 생성량과 조성의 변화에 대응할 수 있도록 하였으며, WGS 반응기로 들어가는 합성가스를 가스 컴프레서를 통하여 최대 10기압으로 승압시키고, 고농도 일산화탄소의 효과적인 제거 및 열 회수 극대화가 이루어질 수 있는 최적의 가스처리 시스템으로 구현되도록 하였다. 설치 완료된 WGS 반응기의 성능시험을 플라즈마 처리설비와 연계하여 수행하였다. 합성가스 내 각각 34%와 25%의 일산화탄소 및 수소의 농도가 WGS 반응기를 거친 후, 일산화탄소는 0.1% 미만으로 제거되었으며 수소는 44%로 증가하여 WGS 반응기의 성능 수준이 매우 우수함을 확인하였다. 차기 년도에 설치/가동 예정인 수소 생산용 PSA는 최대 10기압 운전 및 상압재생 방식으로 운전되며 생산된 수소는 최소 99.99%이상의 고순도를 유지할 것으로 기대된다.

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EFFECT OF AGE ON THE LEVEL OF SERUM ALKALINE PHOSPHATASE ACTIVITY OF JAPANESE BLACK STEERS

  • Sekine, J.;Udagawa, K.;Morita, Z.;Oura, R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.2 no.2
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    • pp.99-102
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    • 1989
  • The level of serum alkaline phosphatase activity was determined in 7 Japanese Black steers at different ages. The isoenzyme activity of non-bone origin was estimated using a heat-inactivation technique. The activity of serum alkaline phosphatase (SALP, K-A unit) decreased as age (AGE, mo.) increased: SALP = 14.15 - 0.17 (${\pm}\;0.03$) AGE, r = -0.81, P<0.01, $S.E.\;{\pm}\;0.28$. The variation of the activity was greater in younger age than the older. The temperature of $58^{\circ}C$ for the treatment of heat inactivation of bovine serum appeared to be suitable. The percentage of heat inactivated enzyme activity negatively correlated with age and positively with the level of serum alkaline phosphatase activity. The activity of SALP of non-bone origin was inferred to stay at about constant level irrespective of age and that of bone origin decreased with age.

Full Rig Test and High Altitude Ignition Test of Micro Turbojet Engine Combustor (초소형 터보제트엔진 연소기의 리그시험 및 고고도 점화시험)

  • Lee, Dong-Hun;Kim, Hyung-Mo;Park, Poo-Min;You, Gyung-Won;Paeng, Ki-Suk
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.05a
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    • pp.373-376
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    • 2009
  • A full rig combustor test and altitude ignition test were carried out for radial-annular combustor of micro turbojet engine. 11.2% total pressure loss and 99.85% of combustion efficiency were measured at design point of engine under sea level standard condition and $2{\sim}6$ of air excess ratio for ignition envelope was achieved on engine starting regime. Finally, A 30,000 ft high altitude ignition test was also performed and finally we found out that the developed radial-annular combustor is appropriate to micro turbojet engine.

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Hydrogen production by plasma pyrolysis-gasification of waste (폐기물의 플라즈마 열분해-가스화에 의한 수소생산)

  • Lee, Jin-Ho;Kim, Young-Suk;Do, Chul-Jin;Hwang, Soon-Mo;Jeong, Seong-Jae
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.627-632
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    • 2007
  • 폐기물의 플라즈마를 이용한 열분해-가스화-용융 처리공정은 청정연료 형태로 정화된 합성가스를 얻을 수 있고, 이 합성가스를 WGS 반응과 PSA 공법을 이용하면 고순도 수소로의 전환 및 회수가 가능하다. (주)애드플라텍에서는 자체 보유하고 있는 3톤/일급 플라즈마 폐기물 처리설비와 수소 정제/회수시스템을 연계하여, 폐기물로부터 고순도 수소 생산 ($20Nm^3/h$ 이상)을 위한 플라즈마 폐기물 처리 수소 생산 통합시스템 개발을 진행하고 있다. 합성가스 내 질소 농도를 낮추기 위해 산소를 매질로 하는 100kW급 산소 플라즈마 토치를 제작 하였다. 수소 정제/회수 시스템은 폐기물의 플라즈마 처리 후의 합성가스 생성량과 조성의 변화에 대응할 수 있도록 하였으며 WGS 반응기로 들어가는 합성가스를 가스 컴프레서를 통하여 최대 10기압으로 승압시키고, 고농도 일산화탄소의 효과적인 제거 및 열 회수 극대화가 이루어질 수 있는 최적의 가스처리 시스템으로 구현되도록 하였다. 설치 완료된 WGS 반응기의 성능시험이 플라즈마 처리설비와 연계하여 수행되었으며 WGS 반응기를 거친 일산화탄소의 농도는 1.5% 미만으로 분석되었다. 차기 년도에 설치/가동 예정인 수소 생산용 PSA는 최대 10기압 운전 및 상압재생 방식으로 운전되며 생산된 수소는 최소 99.99%이상의 고순도를 유지할 것으로 기대된다.

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The Effects of Fabrication Variable on the Characteristics of Simulated Spent Fuel (모의 사용후핵연료의 특성에 미치는 제조변수의 영향)

  • 강권호;류호진;배정현;송기찬;양명승
    • Journal of Energy Engineering
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    • v.10 no.3
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    • pp.278-285
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    • 2001
  • In this study, the effects of the variables on sintering of simulated fuel to simulate the spent fuel are described. Mainly, the effects of compaction pressure, sintering temperature and time on the density of pellet are described. The experimental is performed with compaction pressure of 1 ton/$\textrm{cm}^2$~4 ton/$\textrm{cm}^2$, sintering temperature of 167$0^{\circ}C$, 173$0^{\circ}C$ and 178$0^{\circ}C$ and sintering time of 4 hr, 8 hr and 24 hr. The green density of simulated fuel is proportional to the one third power of compaction pressure and the sintered density is 90.5~99.6% of theoretical density. The grain growth exponent and activation energy of simulated fuel is 2.5 and 287.97 kJ/mol, respectively.

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A Study on the Friction and Wear Characteristics with Purity on $AL_{2}O_{3}$ Ceramic ($AL_{2}O_{3}$ 세라믹의 순도에 따른 마찰 마모 특성 연구)

  • Jeon Chan-Yeal;Oh Seong-Mo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.5
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    • pp.439-445
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    • 2005
  • The tribological properties of ceramics are very important in the application to engineering ceramic parts such as seal rings, pump parts, meter parts, and so on. In this study, the effects of each other purity on the mechanical and tribological properties of alumina and zirconia ceramics were investigated. Sliding distance, sliding speed, contact load. friction coefficient, the amount of worn out material at a certain time, and the prepared composites were measured. Crystalline phases and microstructure were examined with XRD and SEM. We obtained the good properties of friction coefficient and wear resistance at the purity 99.7$\%$ of alumina. However, The purity 95$\%$ were great at the wear amount of worn out material.

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Development and Test of Slinger Combustor for Micro Turbojet Engine (초소형 터보제트엔진 슬링거 연소기의 개발과 시험)

  • Lee, Dong-Hun;You, Gyung-Won;Choi, Seong-Man;Kim, Hyung-Mo;Park, Poo-Min;Choi, Young-Ho;Jeon, Byung-Ho;Park, Soo-Hyung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.11a
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    • pp.149-152
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    • 2008
  • A slinger combustor which can be applied to micro turbojet engine has been developed with the combustor rig test. A rotating fuel injector with high speed rpm was designed, manufactured and tested to apply into slinger combustor through spray test and adequate droplet size and spray distribution were achieved. The CFD was used to analyze internal flow of the combustor. We found out that the combustor shows 11.2% of pressure loss and 99.8% of combustion efficiency at full combustor rig test.

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