말단선량계의 광자선량당량환산인자에 대한 이론적 계산

김광표,이원근,김종수,윤여창,윤석철,Kim, Kwang-Pyo,Lee, Won-Keun,Kim, Jong-Su,Yoon, Yeo-Chang,Yoon, Suk-Chul 대한방사선방어학회 1996 방사선방어학회지 Vol.21 No.1

중성자 및 전자 그리고 광자 수송코드인 MCNP 4A코드를 이 용하여 ANSI N13.32에 제안된 말단팬텀과 한국원자력연구소 제작한 말단팬텀 각각에 대하여 감마선량당량환산인자를 커마근사법에 근거하여 계산하였다. 본 계산은 $15keV{\sim}1.5MeV$ 에너지영역에 대해 단일광자에너지 선원을 고려하였으며 이러한 단일광자에너지함수로서 계산한 공기커마에 대한 선량당량의 비로서 선량당량환산인자를 이론적으로 도출하였다. 본 연구에서 이론적 방법으로 도출한 ANSI와 KAERI의 말단팬텀 각각에 대한 광자선량당량환산인자를 ANSI N13.32의 실험적 방법에 의해 제시된 값들과 비교한 결과 50keV 이상의 단일 광자에너지영역에서는 실험적 방법에 의한 값들과 최대차이 5.7% 내에서 잘 일치함을 보였다. 그러나 40 keV 이하의 에너지영역에서는 본 연구의 계산 결과가 최대 13.6%까지 낮게 평가됨을 알 수 있었으며, 이러한 차이는 낮은 에너지영역에서 두드러지는 단일에너지의 생성과 관련된 실험의 불확실성과 MCNP코드에서 모사한 Geometry의 영향에 기인하는 것으로 사료된다. In this study, the theoretical calculation of the air kerma-to-dose equivalent conversion factors was performed with a Monte Carlo N-Particle transport code for the two types of extremity phantom of the ANSI and the KAERI, respectively. Considering the distribution of absorbed dose due to the interaction of homogeneous Parallel broad beam of monoenergetic primary photons in the range between 15keV and 1.5MeV, the air kerma-to-dose equivalent conversion factors based on the kerma approximation were calculated. It is showed that all the theoretical conversion factors of the two types of the extremity phantom for the ANSI and the KAERI agree well with the experimental values of the ANSI N13.32 draft(1995) for each energy within 5.7%, maximum difference ratio, except for 13.6%, difference ratio in the case for the energy of less than 40keV. It is due to uncertainties of experiment occurred in the low X-ray energy range and geometry considered in the MCNP code.

KSTAR 토카막 장치 진공 기술 현황

김광표,김현석,Kim, Kwang-Pyo,Kim, Hyun-Seok 한국진공학회 2017 진공 이야기 Vol.4 No.1

Recently, KSTAR, Korea's superconducting fusion energy research and development device, has succeeded in driving the high performance plasma for 70 seconds for the first time in the world. Continuous plasma operation technology is an essential factor for commercialization of fusion energy power generation. Therefore, this achievement is expected to play a major role in the research of fusion technology required for future fusion power plants. In order to operate the KSTAR, the discharge process in which the neutral gas is turned into the plasma should be preceded in the start-up (breakdown) phase of tokamak operation. This process essentially involves the vacuum environment in the tokamak device. KSTAR has successfully operated a vacuum pumping system to achieve the target level of the vacuum environment through a high temperature baking operation, a discharge cleaning process and boronization.

KSTAR PFC GN<SUB>2</SUB> BAKING SYSTEM 의 최적설계와 운전결과에 관한 연구

김상태(Kim Sang Tae),김영진(Kim Young Jin),정남용(Jung Nam Yong),임동석(Im Dong Seok),김광표(Kim Kwang Pyo),방은남(Bang Eun Nam),김경민(Kim Kyung Min),김양수(Kim yang Su),권면(Kwon Myeun),유성연(Yoo Seong Yeon) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

PFC nitrogen gas (GN<SUB>2</SUB>) baking system is a closed-loop system and consists of a compressor (nitrogen gas), a electric heater, a pre-cooler (gas vs. gas), a cooler (gas vs. water), a vacuum pump, etc. The system has the following characteristics: 1)Because the compressor cannot be operated at 350℃, the cooler is installed at its suction pipe in order to keep its suction gas temperature below 90℃; 2) The high temperature nitrogen gas fed into the PFC source an energy from compression heat of the compressor and heat retrieved of the pre-cooler to reduce the heaters capacity and those become saving operational energy highly; 3) The heater power is regulated by the temperature of the heater outlet gas through feedback control. For the heating operation in the fourth campaign, the temperature of GN<SUB>2</SUB> supplied was raised to 300℃; PFC temperature reached 250℃. This paper describes the optimum design of PFC GN<SUB>2</SUB> baking system and its operating results.

산소공급이 제한된 상태에서 자란 대장균 하이드로지나아제 동위효소 1 의 순수분리

정현순,김광표,양철학 ( Hyun Soon Jong,Kwang Pyo Kim,Chul Hak Yang ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.4

The hydrogenase isoenzyme I from anaerobically grown E. coli has been purified to homogeneity. The hydrogenase isoenzyme I was solubilized from the membrane fraction by sodium deoxycholate, and purified by (NH₄)₂SO₄ precipitation, DEAE chromatography, gel filtration by Sephacryl S-300, second DEAE chromatography, and hydrophobic interaction chromatography. This isoenzyme I was purified 56-fold to a specific activity or 34.1 U/㎎ of enzyme, with a recovery of 1.35% as judged by hydrogen microevolution assay. The molecular weight of this enzyme was about 180 kDa. The hydrogenase isoenzyme I was composed of equimolar polypeptides of molecular weights 64 kDa and 30 kDa.

대장균 하이드로지나아제 동위효소의 순수분리 및 동위효소의 특성 연구

정현순,김광표,양철학 ( Hyun Soon Jong,Kwang Pyo Kim,Chul Hak Yang ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.4

The hydrogenase isozyme I and II from E. coli were electrophoretically distinct. The hydrogenase isoenzyme I has been purified to homogeniety by using of non-dissociating neutral PAGE containing 0.1% (v/v) Triton X-100. The hydrogenase isoenzyme I was solubilized from the membrane fraction by sodium deoxycholate, and purified by (NH₄)₂SO₄ precipitation, DEAE chromatography, gel filtration by Sephacryl S-300, second DEAE chromatography, and hydrophobic interaction chromatography. The isoenzyme I was purified 56-fold to a specific activity of 34.1 U/㎎ of enzyme, with a recovery of 1.35% as judged by hydrogen microevolution assay. The hydrogenase isoenzyme I was a tetramer (α₂β₂) composed of equimolar polypeptides of molecular weights 64 kDa and 29 kDa. The molecular weight of this enzyme was about 180 kDa.

파이프의 고유진동수를 이용한 액체밀도측정 센서개발

장경호,이용재,김광표,안병덕 ( KYung Ho Chang,Yong jae lee,kwang Pyo kim,Byung Duk Ahn ) 한국센서학회 1995 센서학회지 Vol.4 No.3

For the development of liquid density measuring sensor using the natural frequency of a pipe, its principle and construction method were described. The stainless steel pipe, which has length of 3 cm, inside diameter of 2.3 cm and outside diameter of 2.5 cm, was used for the sensor. The exciting coil and the photo sensor were used to excite and to pick-up it, and the feedback circuit was designed to continue its vibrating. The natural frequency was consistent with the result of the spectrum analysis. It had a linearity of 0.0027 % and a sensitivity of 0.032 in liquid density range from 0.8 g/㎤ to 1.4 g/㎤ and its frequency variation ratio was 0.024 %/℃ in temperature range from 10℃ to 35℃.

우유와 커피 모델 시스템에 적용된 저열량 감미 소재의 감미도와 감미질

최지혜(Ji-Hye Choi),김광표(Kwang-Pyo Kim),정서진(Seo-Jin Chung) 한국식품과학회 2013 한국식품과학회지 Vol.45 No.6

본 실험에서는 바나나향 우유와 커피시스템에 저칼로리 감미료를 첨가할 때 설탕 대비 상대감미도를 측정하고자 하였다. 아울러 바나나향 우유와 커피시스템에서 유지방과 식물성크림이 각 시스템의 관능적 특성에 끼치는 영향을 함께 보고자 하였다. 감미료의 종류는 설탕과 더불어 대체감미료로 tagatose, xylose, erythritol, sucralose, 그리고 효소처리 stevia를 분석하였다. 바나나향 우유의 경우 설탕 5% 첨가 수준을 기준으로 이전 연구에서 도출된 수용액상의 상대감미도를 적용하여 각 대체 감미료의 농도를 이에 맞게 첨가하였으며 커피시스템의 경우 설탕 5.9% 농도 수준으로 적용하여 실험을 진행하였다. 각 감미료 별 적용된 설탕 대비 상대감미도는 다음과 같다: Tagatose 0.83배, xylose 0.63배, erythritol 0.60배, sucralose 556배, 그리고 stevia 64배이다. 각 감미료가 바나나향 우유시스템과 커피시스템에서 발현되는 단맛강도와 기타 관능적인 특성을 이해하기 위해 묘사분석 전문 패널 10명을 활용하여 묘사분석을 실시하였다. 실험결과 바나나향 우유시스템의 경우 stevia를 제외하고는 일반수용액상의 상대감미도와 동일하였으며 stevia는 상대감미도가 감소하였다. 식물성크림 첨가 커피도 동일한 경향을 보였으나 블랙커피의 경우 stevia 외에 xylose와 tagatose의 상대감미도 또한 감소하였다. 바나나향 첨가 우유시스템의 경우 설탕 첨가 시료와 감미질이 유사한 시료는 tagatose와 sucralose 첨가 시료였던 반면 커피시스템의 경우 tagatose와 erythitol첨가 시료인 것으로 나타났다. 지방함량에 따라 바나나향 우유와 커피시스템의 관능적 특성은 매우 달라지는 것으로 분석되었다. 본 연구에서는 기존 수용액상 도출된 감미도가 적용되는 식품시스템에 따라 새롭게 조정되어야 하며 설탕을 대체할 최적 감미료는 적용되는 식품시스템에 따라 달라진다는 것을 보여 주었다. This study investigated the relative sweetness of various sweeteners (tagatose, xylose, erythritol, sucralose, and enzyme treated stevia) in milk and instant coffee systems. Additionally, the effects of interactions with other ingredients on the sensory characteristics of milk and coffee were explored. In the case of a banana-flavored milk system, sucrose was added to a concentration of 5%, and the five types of sweetener were added to a concentration of equal sweetness to a 5% concentration of sucrose. For coffee systems, 5.9% sucrose level and sweeteners concentration equivalent to this level was added. A generic descriptive analysis was performed using ten trained panelists. The results showed that the relative sweetness of all the sweeteners was identical to that identified in the aqueous system, except for stevia in the milk system and in the coffee system with added vegetable cream. For the black coffee system, the relative sweetness decreased for tagatose, erythritol and for stevia. Fat and vegetable cream significantly affected the sensory qualities of milk and coffee, respectively.

Effect of flow imbalance on the operational performance of the KSTAR PF superconducting magnets system

Hyunjung Lee(이현정),Jinsub Kim(김진섭),Chu Young(추용),Kwang Pyo Kim(김광표),Kabrai Park(박갑래) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12

A cryogenic circuit for large scaled superconducting device like a tokamak is installed quite complex. In the KSTAR tokamak, the five cryogenic circuits are managed for cooling of each components (Toroidal Field magnets, Poloidal Field magnets, structures current leads, thermal shield, buslines) independently. The circuit for the Poloidal Field magnets branches into one hundred cooling channels. Five cryogenic valves are controlling the flow rates according to cooling channel length. The KSTAR PF1 upper and lower magnets have ten cooling channels parallel respectively. The pressure drop of the magnets is adjusted by cryogenic valve and is maintained by a supercritical helium circulator. The flow rate should be uniform among the cooling channels or magnets but the flow imbalance was observed during the flow test of magnet individually. The measured imbalance was around 10 % between KSTAR PF1 upper and lower. To investigate for effect of the flow imbalance on the magnet, the simple model of the PF1 upper and lower magnets has been developed using SUPERMAGNET code. The maximum temperature trends are studied in details depending on the imbalance.

전후 자본주의경제의 동향에 관한 고찰

박철범(Park, Chul-Bum),김광표(Kim, Kwang-Pyo) 조선대학교 지식경영연구원 1999 기업과 혁신연구 Vol.22 No.2

The novel serine/threonine protein kinase of Streptomyces coelicolor A3(2) regulates SAM induced-antibiotics production

Soo Jae Lee(이수재),Jihye Kim(김지혜),Choonshik Shin(신춘식),Yoongho Lim(임융호),Joong-Hoon Ahn(안중훈),Kwang Pyo Kim(김광표) 한국생물공학회 2005 한국생물공학회 학술대회 Vol.2005 No.10