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

養漁飼料의 添加物로서 라이신 效果에 關한 硏究

劉奉錫,李廷烈,金鐘連 군산대학교 1991 群山水産專門大學 硏究報告 Vol.25 No.2

To investigate the effect of lysine as a additive to fishfeed, a series of studies on Israeli carp(Cyprinus carpio) and eel(Anguilla japonica) were carried out during the cultivation period of 124 days. During the cultivation periods, the daily growth and growth rate were appeard 0.55g and 6.7times for elver, 1.11g and 4.0 times for young eel, 40.97g and 2.8 times for preadult eel, 1.96g and 3.8 times for fingerling carp, 14.94g and 6.1 times for preadult early, and 161.31g and 2.0 times for adult Israeli carp, respectively. The effect of lysine as a additive to fishfeed were respectively showed superior results in 0.3% for elver, in 0.1% for young eel, and in 0.5% for Israeli carp. But not shown the effect of lysine in preadult of eel. As a results, it was considered that a amounts of lysine added recommend to fishfeed 0.1% of lysine for elver and 0.5% for Israeli carp.

측두하악관절 내장 환자의 관절원판과 관절원판 후조직의 자기공명영상 신호강도

정연화,조봉혜 대한구강악안면방사선학회 2001 Imaging Science in Dentistry Vol.31 No.2

Purpose : To analyze the possible association between magnetic resonance imaging signal intensity of temporomandibular joint disk and posterior attachment, and the type and extent of disk displacement, disk configuration, effusion and clinical signs in patients with internal derangement. Materials and Methods : Magnetic resonance images of the 132 temporomandibular joints of 66 patients with temporomandibular joint displacement were analyzed. The clinical findings were obtained by retrospective review of the patients' records. The type and extent of disk displacement, disk configuration and effusion were evaluated on the proton density MR images. The signal intensity from the anterior band, posterior band and posterior attachment were measured on MR images. The associations between the type and extent of disk displacement, disk configuration, effusion and clinical signs and the MR signal intensity of disk and posterior attachment were statistically analyzed by student's t-test. Results : Of 132 joints, 87 (65.9%) showed anterior disk displacement with reduction (ADR) and 45 (34.1%) showed anterior disk displacement without reduction (ADnR). The signals from posterior attachments were lower in joints with ADnR than those of ADR (p〈 0.05). The results showed statistically significant (p〈 0.05) association between the type and extent of disk displacement and disk configuration, and decreased signal intensity of posterior attachment. There were no statistical associations between pain, noise and limited mouth opening, and signal intensity of disk and posterior attachment. Conclusions : The average signal from posterior attachment was lower in joints with ADnR than that of ADR. The type and extent of disk displacement and disk configuration appeared to be correlated with the signal intensity from posterior attachment. (Korean J Oral Maxillofac Radiol 2001;31:93-9)

The Copepods(Calanoida, Cyclopoida and Harpacticoida)around Cheju Island, Korea(Crustacea)

오봉철,고유봉,고방연 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.

장구균의 동정에 대한 PCR 방법의 유용성

최연화,이영선,김홍빈,김치경,김봉수 대한감염학회 2001 감염 Vol.33 No.2

Background : Enterococci are important cause of nosocomial infections. Recently, vancomycin-resistant enterococci (VRE) has been increasingly reported as significant nosocomial pathogens. Therefore, accurate identification of enterococcal species is a prerequisite step for the appropriate antibiotic treatment and epidemiologic surveillance. We wanted to know the usefulness of PCR method compared with Vitek automatic identification system. Methods : Totally 105 isolates were identified on the species level by Vitek (GPI card and software version R06.1), methyl-α -D-glucopyranoside test, and PCR methods. Results : Among 105 enterococcal isolates, 59 were identified as E. faecium, 11 E. faecalis, 6 E. gallinarum by Vitek. But 29 isolates (28%) were unidentified. Subsequently all of these isolates were analyzed by PCR, the results of which were as follows : 17 E. faecium, 5 E. casseliflavus, 7 E. gallinarum. Two isolates identified as E. gallinarum by Vitek were reidentified as E. casseliflavus by PCR and other methods far phenotypic characterization. Conclusoin : PCR method was more accurate and sensitive than Vitek for the identification of enterococci species. (Korean J Infect Dis 33:123∼127, 2001)

계면활성제 혼합 천연지방산유지 고형 비누의 세척성 및 생분해성 연구 : 생분해성을 중심으로 On Based Biodegradation

이봉연,류덕환,이태관 한국의류산업학회 2003 한국의류산업학회지 Vol.5 No.3

The purpose of the study was to get the valuable data for developing the new natural fat soaps which have an excellent biodegradation performance. Thus, natural fat soaps mixed with the two types of detergents (AOS and LAS) on the various concentrations were made and the biodegradation of the samples were analysed by Dissolved Oxygen method using active sludge. Also, the results were compared with the commercial synthetic detergents and market soaps. The results from the study were the followings: I. The plant fat soap and the wasted oil soap with the concentration of 5 mg/i and 15 mg/1 had an excellent biodegradation rather than animal fat soap. 2, There was little difference among samples with the concentration of 5 mgtl, but there was much difference among them with the concentration of 15 mg/l. 3. The periods for consuming oxygen of wasted oil soap mixed AOS and LAS was the fastest.

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.

Cation이 Europium, Praseodymium인 Nitroprusside [Fe(CN)?NO]²­ 분말내의 중심 원자인 철에 대한 M?ssbauer parameters

劉演奉 삼척대학교 1997 論文集 Vol.30 No.3

We observed the ?Fe Mossbauer spectra for the ground states at room temperature of sodium nitroprusside. Na₂[Fe(CN)?NO]·2H₂O single crystal. europium notroprusside. Eu₂[Fe(CN)?NO]₃·9H₂O powder. praeseodymuim nitropruside and Pr₂[Fe(CN)?NO]₃·6H₂O powder which is substituted cations as rare earth metal element. The M??ssbauer parameters. isomer shifts (I.S.). quadrupole splittings (Q.S.) and full width half maxima (F.W.H.M.T.) of the ground state in two powder samples are compared with ground state of sodium nitroprusside single crystal for analysis of the electronic properties of the materials. We have found that values of quadrupole splitting for ground state in two powder samples are positive larger than these parameter in sodium nitroprusside single crystal and values of ?????? shifts of these for ground state in there samples are equal within experimental errors.

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.