막 접촉기-탈거탑 복합 공정을 이용한 이산화탄소 분리회수

연순화,서봉국,박유인,이규호 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.6

중공사막 접촉기를 기존의 흡수장치에 흡수기로 도입하여 구축한 hybrid 시스템을 이용하여 이산화탄소의 분리·회수에 관한 연구를 수행하였다. 분리효율이 우수한 중공사막 접촉기를 개발하기 위해 다양한 구조적 특성을 가지는 PVDF, PTFE 및 PP 중공사막을 이용하여 혼합 기체 및 흡수제 유량 등의 운전조건에 따른 이산화탄소 제거효율 특성을 조사하였다. 그 결과 중공사막 접촉기가 기존의 충진 흡수탑에 비해 큰 기-액간의 접촉면적으로 인해 분리효율이 높았으며, 그 중에서도 PVDF 중공사 막이 안정된 기-액간의 계면을 유지함으로서 다른 중공사막에 비해 우수한 분리효율을 나타내었다. 또한, 흡수제의 종류(H_2O, K_2CO_3, MEA)에 따른 흡수성능을 조사하고, CO_2-MEA계에서 각 중공사막에 대한 물질전달 특성을 비교하였다. 이산화탄소 분리효율, 경제성, 물질전달 특성 등을 고려하면, MEA를 흡수제로 사용한 경우, PVDF 중공사막이 막 접촉기로서 가장 적합할 것으로 기대된다. Membrane contactor-stripper hybrid process was used to recover CO_2 from the flue gas. Porous PTFE, PVDF, PP hollow fiber modules were used as the membrane contactor. The CO_2 was removed by the porous polymeric hollow fiber membrane contactor using H_2O, K_2CO_3 or monoethanolamine(MEA) solution as the absorbent. Then, the CO_2 was recovered from the absorbent by the thermal stripping tower with steam. The membrane contactor increased the gas-liquid contactor area and mass transfer coefficient, and thus the hybrid process showed a higher CO_2 removal efficiency than the conventional absorption tower. PVDF module with smaller pore size showed the most stable gas-liquid interface and the highest removal efficiency among the hollow fiber membrane contactor modules. gas

카드뮴 정맥주사시 랏트의 치사율과 간, 신에서의 양-반응관계

김인봉,박정덕,홍연표,장임원 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.4

To investigate the lethality and dose-response relationship in liver and kidney of rats at 48 hours after cadmium exposure, single doses of cadmium chloride were given to Sprague-Dawley male rats by tail-intravenous injection with several groups of doses ranging from 2 to 8 mg CdCl_2/kg for lethality and from 0.2 to 3.2 mg CdCl_2/kg for dose-response relationship. In addition, control was treated with distilled water by same method. Hepatic and renal cadmium concentrations were analyzed with I.C.P.(Inductively Coupled Plasm) Emission Spectrometry (Jobin Yvon, Model JY 24, France). Dosages over 4 mg/kg were relevant to LD_100 and LD_50 was calculated as 3.3 mg/kg at 48 hours after cadmium chloride exposure in rat. The concentration in liver and kidney were increased according to given doses, and dose-response relationship was expressed as log Cd in liver= 0.8799+0.913×log Dose (F=1116.1, r=0.9877) and log Cd in kidney= 0.2542+0.0653×log Dose (F=884.8, r=0.9845), respectively. Also, the correlation between hepatic and renal cadmium concentration was highly significant(p<0.01), and dose-response relationship was expressed as long Cd in kidney = -0.6649+1.0259×log Cd in liver (F=411.1, r=0.9676). I consider that this data will be useful for the further studying of low-dose cadmium toxicity.

제주도 연안역 부유성 요각류의 출현과 주요종의 계절변화

고유봉,오봉철,고방연,손태준 제주대학교 해양연구소 1994 해양자원연구소연구보고 Vol.18 No.-

중성자 조사된 원자로압력 용기에 대한 풀림 효과

劉演奉 三陟大學校 1999 論文集 Vol.32 No.3

To estimate the thermal annealing effect of the nuclear reactor pressure vessel (RPV) by the fast neutron (En>1MeV) irradiation, we have studied the change of the Mossbauer parameters of RPV steel with the fast neutrons dosage of 1, ??, ?? n/㎠. DSC experiment was done to find annealing temperature of all samples, so all samples were annealed at 600℃ for 1, 2, 3 and 4 hours respectively. The influence of neutron irradiation on RPV steel was studied by Mossbauer effect. The Mossbauer spectra for all samples showed the superposition of two sextets and one doublet at room temperature. The isomer shift(I. S.) and quadrupole splitting(Q. S.) values of sextets were changed within experimental errors for all samples, but these values of doublet were rapidly changed at the sample of the dose ?? n/㎠. The magnetic hyperfine field was varied within ±3%. For thermal annealing, we can not found any particular change in the values of I.S. and Q. S. But in Geff. we think that there were any annealing effect for the dose 1016 n/㎠ after 3 hours annealing time.

하악과두의 인위적 병소에 대한 악관절 촬영법의 판독능 비교연구

조봉혜,정연화,정희정 大韓口腔顎顔面放射線學會 1997 Imaging Science in Dentistry Vol.27 No.2

The purpose of this study was to evaluate the detectability of various radiographic techniques for mandibular condylar lesions. Erowive lesion, osteophyte and flattening were formed on the artificial mandibular condyle, and panoramic, transcranial, transorbital radiography, lateral and frontal tomography were taken. The results were as follows; 1. The detectability for erosive lesions was superior in the order of frontal tomography(96%), lateral tomo-graphy (78%),transorbital(59%), transcranial(56%) and panoramic(48%)radiography. 2. The location of erosive lesion that showed the highest detectability was the medial third in panoramic, the lateral third in transcranial, the central portion of anteroposterior direction in transorbital, the central portion of mediolateral direction and the posterior third in lateral tomography. Frontal tomography disclosed all erosive lesions except one anterolateral lesion. 3. The detectability of osteophyte was 100% in lateral tomography, 78% in transcranial and 56% in panoramic radiography. 4. For flattening, lateral tomography showed the flattened condyle, but both panoramic and transcranial views showed only decreased bone density without the change of condylar shape.

Mo¨ssbauer 분광법에 의한 Ni_(0.8)Zn_(0.2)Fe₂O₄Ferrite에 대한 연구

유연봉,백승수 三陟大學校 産業科學技術硏究所 2003 産業科學技術硏究論文集 Vol.8 No.2

페라이트계 전파흡수체로 사용되이지고 있는 Ni_(0.8)Zn_(0.2)Fe₂O₄를 택하여 800~1100℃각 2시간씩 소결하여 자료를 합성하여 조사하였다. 고온에서 소결할수록 모분발의 XRD peak는 감소하여 spinel ferrite peak이 우세하였으며, 입자의 크기는 증가하였다. 또한 보자력은 감소한 반면 magnetization saturation은 증가하였다. 따라서 본 실험에서는 fernte 제주의 합성온도 1100℃에서 양실의 시료를 합성화하였고 보문말의 ferrite합성이 1100℃에서 가장 활발하였다.

하악 비대칭의 방사선학적 연구

정연화,조봉혜 大韓口腔顎顔面 放射線學會 1998 Imaging Science in Dentistry Vol.28 No.1

The purpose of this study was to perform the radiographic measurements and temporomandibular joint evaluation in mandibular asymmetry. For this study, thirty-two patients who have mandibular asymmetry were selected and submentovertex, panoramic and lateral corrected tomographic radiographs were taken. Horizontal and vertical analysis using various landmarks on these radiographs were performed. Also radiographic and clinical evaluation of temporomandibular joint were obtained. The results were as follows; 1. On the submentovertex radiograph, the mean distance of Pogonion to midline was 5.0±3.8mm. 2. The mean distance of Pogonion to Gonion was 100.6±9.2mm in deviated side and 104.3±9.1mm in contra-lateral side, and there was a significant difference between the deviated and the contra-lateral side(p<0.001). 3. The distance difference of Pogonion to Gonion between the deviated and the contra-lateral side was significantly related to the degree of asymmetry(p<0.001). 4. On panoramic radiograph, the condylar height of the contra-lateral side was significantly longer than the one of the deviated side(p<0.001). 5. On lateral corrected tomogram, bony changes of temporomandibular joint were observed in 11 condyles of the deviated side and 9 condyles of the contra-lateral side. Erosion and osteophyte were the most common changes in both the deviated and the contra-lateral sides.

농어촌 지역의 한방의료 이용 실태에 관한 조사 : 전남 신안군 장산면을 중심으로

宋峰根,黃忠演,文錫哉 圓光大學校 韓醫學硏究所 1992 원광한의학 Vol.2 No.1

The prevalence of disease is affected by cultural factors. Changing cultural and social pattern may modify patterns of disease. Today majority of labor force in rural community is elderly population with a concomitant increase in woman. We investigated prevalence of problems in rural population utilizing oriental medical clinic in Changsan-myon, Shinan-gun, Chunnam. The majority of patients in this area were female and in the 40 to 60s. Muscoskeletal problems had the highest incidence. Low back pain was leading complaints in the muscoskeletal problems and knee pain was the most common complaints in the digestive problems, headache in the neurologic problems. cough in the respiratory problems, hypertension in the circulatory problems, ear problems in the sense organ problems, pruritys in the dermatologic problems, leukorrhea and postmenopausal syndrome in the gynecologic problems, and dysuria and enuresis in the urinary problems. These results suggest that oriental medical physicians have attention to health care and management of the expanding population of elderly and female patients with high incidence of muscoskeietal problems in the rural community.

會計情報 公示量의 擴大가 意思決定의 有用性에 미치는 影響

李鳳連 혜전대학 1992 論文集 Vol.10 No.-

This thesis has put an emphasis on the subject that the users of accounting information should provide the useful information for the economic decision-making. To achieve this aim, accounting information in need of economic decision-making load has been studied, looking into accounting information disclosure load, the ability of its users, and the new field of accounting information disclosure, by means of the concept of accounting information disclosure and its theory to promote its utility. In this study I have found the following consequences: 1. The disclosure should be enlarged, promoting the possibility of information users' understanding. 2. Accounting Information may cause the confusion in the process of decision-making of accounting information user and the negative result to delay the unfair decision--making. 3. There should be an effort to decide the most suitable information load, by applying the person's information processing model' to promote the utility of decision-making. Nowadays the social responsibility of enterprise has increased, and so the persons who have interested group in enterprise have much interest in the enterprise's information. Therefore the managers should do their best to make a responsible decision to provide the useful information, with the responsible consciousness for the persons concerned with enterprise.

韓國人에서 血友病 B 遺傳子(血液凝固因子 Ⅸ)의 構造 및 制限酵素 Dde Ⅰ, MnI Ⅰ 切片길이 多形性에 關한 分子 遺傳學的 考察

이풍연,전봉균,이정민,권오병,권무식 성균관대학교 생명과학자원연구소 1996 生命資源科學硏究 Vol.2 No.2

Hemophilia B, a human chromosome X-linked recessive disease, is a bleeding disorder resulting from defect or abnormality in blood coagulation factor IX. DNA-based prenatal diagnosis or carrier detection for hemophilia B in Korean has been developed by analyzing restriction fragment length polymorphisms(RFLPs). Two polymorphisms( Dde I and Mnl I) were investigated as follow. Genomic DNAs were extracted from blood of 50 females at the age of twenty. The primers were chemically synthesized by the method of phosphoamidite. Mnl I primers were derived from exon 6, while Dde I primers, from the flanking sequences of intron 1 of the factor IX gene. Genomic DNAs were amplified with Mnl I primers to generate 405 nts long fragments in all cases. They were digested with Mnl I to analyze the polymorphic site on agarose gel. No MnlI polymorphic site was found in all cases. Also, the genomic DNAs were amplified with Dde I primers to generate ca. 320 nts long fragments in all cases. These results are not correlated with those obtained from the Caucasian. It suggests that Korean could exhibit different patterns of Dde I and Mnl I polymorphisms in the gene for blood coagulation factor IX. Direct sequencing of the polymorpic sites will confirm the above sugestion.