고감도 CaSO_4 : Dy TL 분말의 TL 특성 및 고감도 TL 소자 제작 Dy TL powder and development of high sensitivity CaSO_4 Dy TL pellet

양정선,박재우,김두영,김장렬,장시영 제주대학교 방사능이용연구소 2002 연구보고 Vol.16 No.-

CaSO_4 : Dy series TL material is widely used as a personal dosimeter because of its high sensitivity to radiation. KAERI(Korea Atomic Energy Research Institute) has been produced CaSO_4 TL powder activated by Dy(rare earth elements) for several years and continually tried to improve its sensitivity having more than that of commercialized Teledyne CaSO_4 : Dy TL powders(USA). The TL powder is prepared by adding 0.1mol% Dy as an activator and by the acid evaporation method at first. And new step of washing this powder by distil-water is appended to separate non-crystalized powder in the initial crystal of CaSO_4 : Dy powder. CaSO_4 : Dy crystal TL powder which is produced by applying this new method has higer sensitivity than before washing step, and it has also higher sensitivity than that of Teledyne CaSO_4 : Dy TL powder. This CaSO_4 : Dy TL powder shows good TL characteristics such as dose response, energy response and fading. It is not possible to make solid detectors of only CaSO_4 : Dy TL phosphor without any binding material. Until now widely used sintered pellets. which were made from a mixture of CaSO_4 : Dy TL phosphor and Teflon. But, due to reduction in content of CaSO_4 : Dy TL phosphor in pellets(15∼20wt%) the TL sensitivity of pellets was reduced correspondingly. To variously use the CaSO_4 : Dy TL phosphor, research for preparing detectors by mixing CaSO_4 : Dy TL phosphor with different binding substances has been conductedThis paper described development of a new type of CaSO_4 : Dy pellets by using P-compounds as a bonding material(KCT-300), and compared the TL sensitivity with that of the commercialized Teledyne CaSO_4 : Dy pellets. Sensitivity of a new developed KCT-300 shows about 6 times than Teledyne ones, and can be used to measure very low radiation dose.

데페록사민 전처치가 토끼 심근경색 크기의 감소에 미치는 효과

양관모,오동렬,박승현,박규남,이원재,김형국,황두영,최승필,채장성 대한응급의학회 1998 대한응급의학회지 Vol.9 No.4

Background: Reperfusion of ischemic myocardium has been postulated to result in a specific oxygen radical mediated tissue injury. Iron may liberate during ischemia and we hypothesized that administration of the iron chelator, deferoxamine during ischemia would result in improved recovery after postischemic reperfusion. Purpose: To test whether iron-catalyzed processes contribute to myocardial necrosis during ischemia and reperfusion, deferoxamine was administered to block iron catalyzed hydroxyl radical formation in rabbits. Methods: Eleven rabbits were divided into two groups : control group (n=5) and deferoxamine pretreatment group (n=6). The left circumflex coronay artery was ligated for 30 minutes and reperfused for 180 minutes. Area at risk (AR) was measured by non-stained area with methylene blue injection into left atrium after left circumflex coronary artery ligation. Infarct size was measured by weighing after triphenyltetrazolium chloride staining. Heart rate was measured using electrocardiographic recording and systemic blood pressure was monitored by pressure transducer connected to the catheter in the left ventricle. Results: 1. There was no significant difference of heart rate and blood pressure in deferoxamine pretreatment group compared with control group. 2. There was significant decrease of serum iron concentration after continuous infusion of deferoxamine compared with serum iron concentration before ligation of coronary artery(P<0.05). 3. There was no significant difference of area at risk between control and deferoxamine pretreatment group. 4. Area at necrosis to area at risk was significantly reduced in deferoxamine pretreatment group compared with control group(P<0.05). The results suggest that deferoxamine infusion prior to coronary artery occlusion has a significant benefit in reducing infarct size in this model.

위의 유암종과 선종의 병발 1례

장재식,강혁주,이중현,서영범,윤병구,김용섭,이구,서정일,양창헌,이창우,김정란,윤환중 東國大學校醫學硏究所 2000 東國醫學 Vol.7 No.-

유암종은 전신에 퍼져 잇는 장크롬친화성 세포에서 기원하는데 위의 유암종은 비교적 드문 질환으로 모든 유암종의 1.9~2.2%에 해당하며 위에 발생하는 종양의 1% 미만에서 보고되고 있다. 유암종은 일반적으로 증상이 비특이적이고 면역조직화학검사에 의해서 진단되기 때문에 과거에는 드물게 발견되었으나 최근 내시경 기기 및 술기의 발전과 검사 빈도의 증가 및 면역조직화학검사의 발달로 진단율이 증가 추세에 있으며, 드물지만 유암종에서 선암과 공존하는 예들이 보고되고 있다. 저자들은 심와부 동통을 주소로 내원한 70세 남자 환자의 상부위장관내시경 검사에서 위체상부의 대만곡에서 0.4×0.4 cm 크기의 중간 함몰을 가진 Yamada 1형의 용종과 함께 전정부의 전벽에서 0.8×0.5 cm 크기의 융기된 점막 소견을 보여 조직학적으로 각각 위유암종 및 위선종임을 확진한 후 내시경적 용종 절제술로 치료한 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Carcinoid tumors are arisen from enterochromaffin cells, which are scattered throughout the body. These tumors are composed of variable numbers of cells that contain endocrine granules in their cytoplasm, which can be identified by immunohistochemistry and electron microscopy. Gastric carcinoid tumors are relatively rare tumor, the reported incidence being 1.9~2.2% of all carcinoid tumors and less than 1% of all gastric tumors. Sometimes, composite carcinoid tumors and adenocarcinoma is reported. We experienced a case of the coincidence of carcinoid tumor and adenoma at the other site of the stomach in a 70 year old male patient. Gastrofiberscope showed 0.4×0.4 cm sized Yamada type I polyp with central depression on the greater curvature of the proximal body and 0.8×0.5 cm sized focal slightly elevated mucosa on the anterior wall of the antrum. The endoscopic biopsy specimens revealed carcinoid tumor and tubular adenoma with moderate atypism, respectively. The carcinoid tumor and adenoma were removed by endoscopic polypectomy. According to the follow-up gastrofiberoscopy after 7 month later, both lesions were nearly normal mucosa except whitish atrophic change after polypectomy.

國産運動用具의 使用에 關한 考察 : 品質水準과 使用實態를 中心으로

梁在根,林繁藏 師範大學 體育硏究所 1984 서울大學校 體育硏究所論集 Vol.5 No.1

The gim of this study is to help the development of athletic competency through the consideration of the use of domestic sporting goods. The conclusions of the study and proposals for desirable plans are as follows; ① Because the kinds and sizes of sporting goods are various, manufactures are consisted of multikinds-little production system and are still scant. ② In 27 sport entries of The Olympics, sporting goods needed to acquire international primary official recognition are 42 kinds of goods, but sporting goods which acquired international primary official recognition by this time, Dec. 31, 1983, are only 6 kinds of goods-target paper of shooting, football, basketball, ping-pong ball, and ping-pong table. ③ Most of the manufactures of sporting goods are small and mediumsized business and have an excessive burden of cost of domestic official recognition. ④ The usable domestic goods and their qualities is the level of 60∼90%. ⑤ The level of qualities is low, for the ball for the domestic ball game is used nearly as the authorized ball of the meeting in The National Athletic Meeting. Proposals for desirable plans are as follows; ① We must produce high-grade goods by a technical tie-up or joint venture with foreign famous company. ② We must shape the brand image of the domestic sporting goods and make domestie brand of our own by acquring the official recognition of game organizations. ③ We must formulate the KS standard and establish quality testing organization. ④ The cost of domestic official recognition for the manufactures of sporting goods which are mostly scant and small and mediumsized business must be diminished. ⑤ We must use our domestic sporting goods acquired international official recognition, then we hold domestic games and international games in our country.

탄화수소에 의한 NO의 선택적 촉매 환원 반응에서 Pt/MCM-48 촉매의 반응 메커니즘에 관한 연구

양재승,이성철,장재훈,이병용,정석진 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

기본형의 Si-MCM-48에 알루미늄 치환량과 귀금속 담지량의 변화에 따라 다양한 촉매를 제조하였고, 이를 탄화수소에 의한 선택적 촉매 환원(HC-SCR)반응에 적용하여 각각의 NO 환원반응 특성을 비교 고찰하였다. Pt/MCM-48 촉매의 NO 환원 활성을 고찰한 결과, 문헌상 보고 되고 있는 Pt/ZSM-5 촉매를 이용한 NO의 제거 활성과 비교하여 매우 우수한 결과를 보였다. 또한 5 vol% 이하의 산소 조건에서 그 활성이 현저하였으며, 특이하게 최고 활성에 도달한 후에 반응온도가 600℃까지 증가하여도 계속하여 그 활성을 유지하였다. XRD, TPD, TGA, XPS 등의 특성화를 통해 촉매의 표면 특성 및 반응 mechanism에 관한 연구를 수행하였으며, 이러한 결과로부터 Pt/MCM-48 촉매가 기존 촉매보다 일정 산소 조건에서 우수한 성능을 보이는 것은 담체의 표면 산특성과 촉매 고유의 redox mechanism에 기인한 것으로 해석하였다. Pt supported on MCM-48 was tested as a new catalyst for hydrocarbon-SCR process. MCM-48 is a new support material of the catalyst for SCR. Characterization and de-NO, activity test were performed for the newly synthesized MCM-48-supported catalysts. Pt(l wt%)/MCM-48 showed 90% of NO reduction at 250-500℃. It should be concluded, from what has been said above, that Pt/MCM-48 catalysts showed higher NO reduction conversion than zeolite based catalyst, and it was not affected by 5 vol% O₂ concentration and water vapor addition. It would be supposed that sustention of activity in that oxygen condition might be caused by surface acidic characteristic and its characteristic redox mechanism.

Global-MAHN에서 라우팅 오버헤드 개선에 대한 연구

張良根,金玄旭,李光培,吳世德,裵振勝,金在浩 明知大學校 産業技術硏究所 2007 産業技術硏究所論文集 Vol.26 No.-

In this Paper, we studied the mechanism that increases the network reliability and decreases network load in GMAHN environment based on the AODV routing protocol. This proposed algorithm is the research on the algorithm, minimizing network overhead by preventing unnecessary network overhead previously and adapting Local repair mechanism to efficient data transmission when route error happens in network, in GMAHN environment. To evaluate the proposed algorithm's performance, we analyzed the proposed algorithm and adapting in various experiment environment according to 5 experiment viewpoint such as node movement, gateway network zone, mobile node number, flow number. After evaluating the experiment, we confirmed better network improvement altogether through following result such as total average data reception rate's increase, average data transmission time's decrease, network overhead's decrease than existing GMAHN algorithm.

보안정책 검증용 사양언어를 위한 파서의 구현 : SPSLP

장재혁,양태연,최용락 대전대학교 산업기술연구소 2001 산업기술연구소 論文集 Vol.12 No.1

It in vary difficult to guarantee the system security when security policy systems have different policy syntax in it. It means that policy data can't be transported correctly because the security negotiation could be failed. So, we have to verify the database of security policy through investigating the syntax and function of the security policy system whether wrong or not. This paper presents the parser, which is developed for the verification of security policy. The implemented SPSL parser makes offers to classify the error, to create the information of the verified security policy used for building the SPS DB and to give both the convenience of management and the flexibility of security policy.

Li 화합물을 첨가한 CaSO₄:Dy 열중성자 측정용 TLD 소자 개발

양정선,김두영,박재우,김장렬,장시영 제주대학교 방사능이용연구소 2003 연구보고 Vol.17 No.-

Personal neutron dosimetry is quite a difficult area because a neutron is always accompanied with gamma radiation, which is required of a capability for mixed field dosimetry. CaSO₄:Dy phosphor is known to have a very high sensitivity to gamma, but the neutron capture cross section of the constituents of CaSO₄:Dy are so small that the interactions between the thermal neutron and the phosphor are rare. One method to improve the neutron interaction is by introducing an impurity ion with a large thermal neutron captures cross section into the phosphor to act as a neutron target centre such as 6Li. In neutron-gamma mixed radiation fields, if two detectors for the 6Li-7Li compounds embedded CaSO₄:Dy TL pellets are used, a 6Li-compound embedded pellet can detect the neutron and gamma radiation together, and the other pellet can only detect the gamma radiation. Recently Korea Atomic Energy Research Institute (KEARI) has developed a new type of CaSO₄:Dy TL materials embedded with phosphorous (KCT-300) to detect beta and gamma radiation with a very high sensitivity[1]. This paper presents the development of CaSO₄:Dy TL pellets embedded with 6Li compound for a thermal neutron measurement, and the detection method of the neutron and gamma dose in mixed fields with CaSO₄:Dy TL pellets embedded with a 6Li compound(KCT-306) and CaSO₄:Dy TL pellets embedded with a 7Li compound(KCT-307) is introduced. The net neutron sensitivity of CaSO₄:Dy TL pellets embedded with 6Li compound developed in this study is higher than that of the TLD-600 (Harshaw Co.) dosimeter which is available in the open market.

Siloxane-Epoxy(s) Copolymer合成에 관한 硏究

梁在乾,韓貞璉,裵長淳 단국대학교 1981 論文集 Vol.15 No.-

Oligosiloxane prepared which has moleculae weight 900∼1,000 was prepared from O.M.C.S. and epoxy(S) resine was prepared from pisphenol(S) and epichlorohydrin. The siloxane-epoxy(S) copolymer was synthesized through the copolymerization of oligosiloxane and epoxy(S) resine under alkaline acetone solution at 50∼55℃ for 5 hours. Thermal properties of epoxy(S) resine and siloxane-epoxy(S) copolymer was measured by thermogravimetric analysis, copolymer with 8.2% silicon content had the higher degradation temperature 300℃ than epoxy(S) reine which degradation at 250℃.

열형광 CaSO₄:Dy 소자의 최적 제조조건에 관한 연구

김장렬,남영미,장시영,김두영,양정선,박재우 제주대학교 산업기술연구소 2000 尖端技術硏究所論文集 Vol.11 No.1

An experimental investigation has been performed to determine optimal conditions for preparing the thermoluminescent CaSO4:Dy pellets which have been widely used as personal radiation dosimeter material. Our investigation has shown that an optimal weight concentration of the dopant Dy in the bulk CaSO4:Dy is 0.1 mol%, and an optimal temperature of adding Dy in the preparing process is 320 ℃. An optimal time and temperature for sintering the CaSO4:Dy crystal produced from the chemical process are found to be 2 hours and 800 ℃, respectively. The maximum thermoluminescent sensitivity was observed when the CaSO4:Dy crystal was pulverized to grain sizes of 63 - 200 ㎛ in diameter before being fabricated into pellets. The commercial Teflon was selected as an adhesive for the fabrication of the CaSO4:Dy pellets with an optimal mixing ratio of the Teflon and CaSO4:Dy being 70 to 30 in weight.