• 제목/요약/키워드: GRS

검색결과 126건 처리시간 0.02초

Ground-based model study for spaceflight experiments under microgravity environments on thermo-solutal convection during physical vapor transport of mercurous chloride

  • Choi, Jeong-Gil;Lee, Kyong-Hwan;Kim, Geug-Tae
    • 한국결정성장학회지
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    • 제17권6호
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    • pp.256-263
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    • 2007
  • For $P_B=50Torr,\;P_T=5401Torr,\;T_S=450^{\circ}C,\;{\Delta}T=20K$, Ar=5, Pr=3.34, Le=0.01, Pe=4.16, Cv=1.05, adiabatic and linear thermal profiles at walls, the intensity of solutal convection (solutal Grashof number $Grs=7.86{\times}10^6$) is greater than that of thermal convection (thermal Grashof number $Grt=4.83{\times}10^5$) by one order of magnitude, which is based on the solutally buoyancy-driven convection due to the disparity in the molecular weights of the component A ($Hg_2Cl_2$) and B (He). With increasing the partial pressure of component B from 20 up to 800 Torr, the rate is decreased exponentially. It is also interesting that as the partial pressure of component B is increased by a factor of 2, the rate is approximately reduced by a half. For systems under consideration, the rate increases linearly and directly with the dimensionless Peclet number which reflects the intensity of condensation and sublimation at the crystal and source region. The convective transport decreases with lower g level and is changed to the diffusive mode at $0.1g_0$. In other words, for regions in which the g level is $0.1g_0$ or less, the diffusion-driven convection results in a parabolic velocity profile and a recirculating cell is not likely to occur. Therefore a gravitational acceleration level of less than $0.1g_0$ can be adequate to ensure purely diffusive transport.

식품접촉물질에 부착된 Listeria monocytogenes의 증식 및 제거에 관한 연구 (Studies on Growth and Decontamination of Listeria Monocytogenes Attached to Food Contact Surface Materials)

  • 윤정희;고영림;나승식;이용욱
    • 한국환경보건학회지
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    • 제27권1호
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    • pp.75-82
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    • 2001
  • Microorganisms can attach firmly to food contact surface material and the resitance of adherent bacteria differ markedly from planktonic cells. Therefore, adherent cells are a potential contamination problem to the food preparation because of their high resistance. to sanitation and heat treatment. This study was carried out in order to investigate growth and decontamination of Listeria monocytogenes attached to stainless steel, glass and plastic. Listeria monocytogenes cells could attach to all types of surface at three temperatures after contact times for 24 hrs. The numbers of adherent cells were greater at higher temperatures, but not increased with incubation time. When recovery of adherent cells was investigated, after 24 grs, the numbers of adherent cells were about 10$^{7}$ , 10$^{10}$ , 11$^{11}$ at 4$^{\circ}C$, $25^{\circ}C$, 3$0^{\circ}C$ repectively. Planctonic cells decreased by 2 log cycles after exposure to the domestic sanitizer. Adherent cells showed high resistance to domestic sanitizers and that was dependent upon surface materials studied, being greatest on plastic followed by stainless steel and glass. Adherent cells were more resistant to heat treatment than planktonic cells. When adherent cells were exposed to the temperature of 5$0^{\circ}C$, 55$^{\circ}C$, 57.5$^{\circ}C$ for 10 min, their populations did not decrease significantly. When the temprature increased to 6$0^{\circ}C$, cells attached to all types of surfaces were completely inactivated for 10 min.

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Gamma-ray Full Spectrum Analysis for Environmental Radioactivity by HPGe Detector

  • Jeong, Meeyoung;Lee, Kyeong Beom;Kim, Kyeong Ja;Lee, Min-Kie;Han, Ju-Bong
    • Journal of Astronomy and Space Sciences
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    • 제31권4호
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    • pp.317-323
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    • 2014
  • Odyssey, one of the NASA's Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of $^{40}K$, $^{232}Th$ and $^{238}U$ in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

세계측지계 전환에 따른 지적 필지별 면적 변화 분석 (Analysis Change of Parcel Boundaries and Area by Transformation World Geodetic System)

  • 곽호선;최윤수;권재현;이원진
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2008년도 공동추계학술대회
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    • pp.350-351
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    • 2008
  • 현재 우리나라의 측량체계는 크게 측지분야와 지적분야로 이원화되어 있으며 측지분야에서는 2001년도에 측량법을 개정하여 ITRF2000좌표계와 GRS80 타원체를 측량기준으로 사용하는 세계측지계를 도입하였다. 하지만 지적 분야에서는 국민의 재산권과 직접적으로 관련이 있는 필지의 경계와 면적의 변화 연구는 미미한 상태이다. 따라서 본 연구는 2010년 세계측지계 도입 후 지적분야에서 발생할 수 있는 필지별 면적 변동에 따른 사회적 혼란 여부를 판단하기 위하여 서울특별시 종로구 숭인등 숭인4구역주택재개발지구를 연구 대상지로 선정하여 세계측지계 전환에 지적 필지별 면적 변화를 분석하였다. 분석결과 연구대상지는 세계측지계와 지역측지계가 종선(X)축으로 305.87m. 종선(Y)축으로 70.87m 편차로 두 좌표계 간 북동방향으로 313.97m의 차이가 있고, 현행성과와 비교한 결과 종선(X) 방향으로는 평균 +4.0cm, 횡선(Y) 방향으로는 평균 -3.0cm의 차이가 나타났으며, 필지별 면적의 변동량은 $1.0m^2{\sim}3.0m^2$ 차이가 있지만 허용오차 범위 내에 있으므로 세계측지계 전환에는 문제점이 없는 것으로 판단된다. 하지만 본 연구의 결과는 그 대상범위가 한정되어 있고 기 검증된 지적기준점 성과를 사용한 결과이므로, 향후 보다 효율적인 세계측지계 전환과 도입을 위해서는 현 지적기준점체계의 정확한 세계좌표계 변환 성과를 기준으로 한 대단위의 필지별 면적 변동량 및 허용범위 분석과 같은 추가적인 연구가 조속히 이루어져야 할 것으로 판단된다.

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흰점박이꽃무지 유충의 혈구세포에 대한 형태학적 특성 (Ultrastructure Characterization of Hemcytes in Larvae of Protaetia brevitarsis seulensis)

  • 조세열
    • 한국응용곤충학회지
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    • 제55권3호
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    • pp.215-221
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    • 2016
  • 본 연구는 흰점박이꽃무지(Protaetia brevitarsis seulensis (Colbe) (Cetoniidae, Coleoptera) 유충의 혈림프에 존재하는 혈구세포들의 형태학적 특성분석을 위하여 수행하였다. 흰점박이꽃무지 유충 혈강 내에는 과립혈구세포, 세포질혈구세포, 편도혈구세포, 구상적혈구세포, 전혈구세포, 지방혈구세포 총 여섯 종류의 혈구세포들이 관찰 되었다. 그 중 과립혈구세포는 핵, 미토콘드리아, 골지체를 포함하여 잘 발달된 세포소기관들이 관찰 되었고 외래물질 침입시 면역학적 식균작용을 수행하는 것으로 밝혀졌다. 특히, 과립혈구세포의 세포질에는 잘 발달된 리소좀(<$1{\mu}m$ 직경)들이 세포막 주변으로 분포되어 존재하고 있음을 알 수 있었다. 식균된 외래물질은 다양한 크기의 리소좀들과 서로 합쳐지면서 외래물질을 제거하는 것으로 판단된다. 그 외 다섯 종의 혈구세포들은 외래물질 침입시 면역학적 활성화와 관계가 없는 것으로 관찰되었다.

역지붕 녹화옥상시스템[KICT-GRS2004]의 우수유출 특성에 관한 실험적 연구 (A Experimental Study on Effluence Characteristic of the Rainfall in the IRMA Green Roof System of KICT)

  • 장대희;김현수;이건호;문수영
    • KIEAE Journal
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    • 제5권2호
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    • pp.11-18
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    • 2005
  • The Purpose of this study is development and analysis of Effluence Characteristic of the Rainfall in the IRMA Green Roof System(developed in KICT) Plus 50 program is an internal research project at KICT(Korean Institute of Construction Technology) which has it as an object ; to lengthen the building's life 50-year or more and reduce energy conception 50% than present. Green roof system is one of the most important theme in the Plus 50 program. Generally, a Green Roof System has a positive effect on the thermal conductivity in winter, the micro cooling effect on building and city by evaporation in summer, the flood-control effect by runoff-reduction or the treated rainwater-quality of green roof system and so on. However, inspection of the physical effect of green roof system does not consider in Korea. Above all, long-term monitoring and a whole observation of green roof system is needed to probate the effect. So a new experimental method could be tried in this research, which is never attempted in Korea. The measurement by a bucket with a great volume, 1L, gives a new dimension of measuring green roof effect to measure the permanent running flood from a wide roof. This offers a reasonable result on a long-term measuring of a running water. Additionally, the thermal behavior of the IRMA(Insulated Roof Membrane Assembly), known in the western europe as a reasonable solution at green roof system by economical benefits and easy construction, would be experimented.

The Effects of Addition Timing of NaCl and Sodium Tripolyphosphate and Cooking Rate on Pink Color in Cooked Ground Chicken Breasts

  • Bae, Su Min;Cho, Min Guk;Jeong, Jong Youn
    • 한국축산식품학회지
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    • 제40권2호
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    • pp.231-241
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    • 2020
  • The current study investigated the effects of timing of NaCl (2%) and sodium tripolyphosphate (STPP, 0.5%) addition and cooking rates on color and pigment properties of ground chicken breasts. Four treatments were tested as follows: treatment 1, no NaCl and STPP added and stored for 7 d; treatment 2, NaCl+STPP added on 0 d and stored for 7 d; treatment 3, NaCl added on 0 d and STPP added on 7 d; and treatment 4, stored for 7 d and NaCl+STPP added. All samples were cooked at a fast (5.67℃/min) or slow cooking rate (2.16℃/min). Regardless of the timing of NaCl and STPP addition, reflectance ratios of nitrosyl hemochrome, cooking yield, pH values, oxidation-reduction potential, and percent myoglobin denaturation were similar (p>0.05) across treatments 2, 3, and 4. The highest CIE a values were observed in treatment 4 (p<0.05), while treatment 2 was effective in reducing the redness in cooked chicken products. The fast cooking rate resulted in lower CIE a values and higher CIE L values and cooking yield in cooked chicken breasts compared to the slow cooking rate. Our results indicate that adding NaCl and STPP to meat, followed by storing and cooking at a fast rate, may result in inhibiting the pink color defect sporadically occurred in cooked ground chicken breasts.

Presalting Condition Effects on the Development of Pink Color in Cooked Ground Chicken Breasts

  • Bae, Su Min;Cho, Min Guk;Jeong, Jong Youn
    • 한국축산식품학회지
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    • 제40권2호
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    • pp.197-208
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    • 2020
  • The effects of presalting conditions (storage temperature and duration) with/without sodium tripolyphosphate (STPP) on the color and pigment characteristics of cooked ground chicken breast were investigated. Meat mixtures containing 2% NaCl (control) or 2% NaCl and 0.5% STPP (STPP treatment) were stored for 0, 3, 5, 7, and 10 d at 2℃ or 7℃, followed by cooking to 75℃, and cooling and storage at 2℃-3℃ until further analysis. The treatment was the most effective on the pink color defect of all independent variables. The effect of storage temperature was only observed on CIE L values and percentage myoglobin denaturation (PMD). The control was redder than the STPP treated samples and the CIE a values increased (p<0.05) from 0 to 5 d in the control and STPP treated samples. Compared to the STPP treatment, the control exhibited increased reducing conditions (more negative oxidation reduction potential), lower undenatured myoglobin, and greater PMD. No differences in the cooking yields of the control and STPP-treated samples were observed for various storage durations. Products with STPP showed higher (p<0.05) pH values than those without STPP, but no differences (p>0.05) in PMD were observed over the storage period in the control and STPP treated samples, except for day 0. Thus, STPP is effective at reducing the pink color in cooked chicken breasts. In addition, presalting for longer than 5 d resulted in increased pink color of the cooked chicken breasts.

LVC 통합 아키텍처 기반 실기동급 ACMI 모의기 개발 (Development of an ACMI Simulator Based on LVC Integrating Architecture)

  • 장영찬;오지현;명현삼;김천영;홍영석
    • 한국항공우주학회지
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    • 제43권6호
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    • pp.540-547
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    • 2015
  • 본 논문은 LVC 통합 아키텍처 기반의 실기동급 ACMI 모의기의 개발 내용 및 비행시험 수행 내용을 기술하였다. ACMI는 공군의 전투 및 작전능력 배양을 위한 모의 공중전투 및 지상폭격 훈련 체계로서 실제 사람이 실제 장비인 전투기를 운용하는 실기동급 시뮬레이션이다. ACMI 모의기는 LVC 통합 아키텍처 기반의 실기동급 전투기에서 데이터 링크 통신을 이용한 가상급, 구성급 시뮬레이션과의 연동 기술을 확보하기 위해 개발되었다. ACMI 모의기는 무인기를 운용하여 전투기의 기동을 모의하였는데, 전투기와 무인기는 상이한 기동 특성을 가진다. 이에 본 연구에서는 무인기의 비행 데이터를 활용한 전투기의 기동 모의 방법을 제안하였으며, 이를 무인기에 적용하여 전투기 기동과의 유사성을 검증하고자 비행시험을 수행하였다.

Deciphering the Genes for Taste Receptors for Fructose in Drosophila

  • Uchizono, Shun;Itoh, Taichi Q.;Kim, Haein;Hamada, Naoki;Kwon, Jae Young;Tanimura, Teiichi
    • Molecules and Cells
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    • 제40권10호
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    • pp.731-736
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    • 2017
  • Taste sensitivity to sugars plays an essential role in the initiation of feeding behavior. In Drosophila melanogaster, recent studies have identified several gustatory receptor (Gr) genes required for sensing sweet compounds. However, it is as yet undetermined how these GRs function as taste receptors tuned to a wide range of sugars. Among sugars, fructose has been suggested to be detected by a distinct receptor from other sugars. While GR43A has been reported to sense fructose in the brain, it is not expressed in labellar gustatory receptor neurons that show taste response to fructose. In contrast, the Gr64a-Gr64f gene cluster was recently shown to be associated with fructose sensitivity. Here we sought to decipher the genes required for fructose response among Gr64a-Gr64f genes. Unexpectedly, the qPCR analyses for these genes show that labellar expression levels of Gr64d and Gr64e are higher in fructose low-sensitivity flies than in high-sensitivity flies. Moreover, gustatory nerve responses to fructose in labellar sensilla are higher in Gr64d and Gr64f mutant lines than in mutant flies of the other Gr64a-Gr64f genes. These data suggest the possibility that deletion of GR64D or GR64F may indirectly induce enhanced fructose sensitivity in the labellum. Finally, we conclude that response to fructose cannot be explained by a single one of the Gr64a-Gr64f genes.