다단 유체통로를 가진 현열축열조의 열역학 제2법칙에 의한 효율성 해석

이근식 울산대학교 1986 연구논문집 Vol.17 No.1

다단 유체통로를 가진 현열축열조의 효율해석이 열역학 제2법칙에 바탕을 둔 생성 엔트로피 개념을 도입하여 수치해석을 통하여 이루어졌다. 생성엔트로피 개념을 도입함으로써 현열축열조의 설계 매개변수들과 새로 정의된 효율들과의 직접적인 관계가 제시되었으며, 효율적인 축열을 하기 위한 매개변수들의 범위가 본 계산범위내에서 제시되었다. 아울러 기존의 제1법칙에 입각한 효율들과도 비교되었다. The numerical analysis for the effectiveness of a sensible heat storage unit with multi-flow channels of working fluid is presented. The irreversibility concept(entropy generation) by the 2nd Law of thermodynamics establishes a relationship between design parameters(e.g. Biot number, Ntu, heat capacity ratio, aspect ratio and the difference between fluid inlet temperature and initial one of heat storage unit) and the usefulwork wasted due to finite temperature difference in heat storage process. This paper presents the conditions for more effective sensible heat storage method according to the variation of heat storage design parameters and compares the new efficiency based on entropy generation with the traditional one based on the lst Law of Thermodynamics.

소아 확장성 심근증의 임상적 고찰

이성환,김준식,박근수,김명성,권태찬,김천수,이상락 啓明大學校 醫科大學 1996 계명의대학술지 Vol.15 No.1

A Clinical assessment of the 25 patients with dilated cardiomyopathy who were admitted to the Department of Pediatrics, Keimyung University Dong San Hospital from January, 1982 to June, 1993 was performed. The result were as follows: 1) Among 25 patients with dilated cardiomyopathy. 8(32%) were younger than 1 year of age at the time of admission. 2) Adriamycin toxicity was the only encountered etiologic factor in 1 patient. 3) On admission, hepatomegaly and tachycardia were noted in almost all patients. 4) The Chest X-rays showed cardiomegalies in all 25 patients, pulmonary vein congestions in 15(60%) and pleural effusion in 2(8%). 5) The electrocardiography showed left ventricular hypertrophy in 72% and supraventricular tachycardia in 32%. 6) The echocardiographic examination showed left ventricular dilatations in all patients and left atrial dilatations in 20(80%). 7) Of 18 patients who had followed mean period of 2.9 years, 10 patients died within 9 months after the diagnosis.

Poplar 組織培養에 의한 anthocyanin 生成

李承雨,崔根元,鄭印植 경희대학교 유전공학연구소 1993 遺傳工學論文集 Vol.5 No.-

Poplar(Populus nigra)를 대상으로 組織培養時 callus 生長과 anthocyanin形成에 影響을 미치는 環境條件으로써 最適培地, 糖의 效果, 植物生長調節劑, 糖의 種類 및 日長의 影響을 검토하고자 遂行한 결과는 다음과 같이 요약된다. 1. SH 培地가 callus 및 anthocyanin형성에 효과적이었고 sucrose濃度는 5.5%가 우수하였다. 2. Auxin류의 효과에 있어서는 2,4-D 2.0 ㎎/ℓ에서 callus 및 anthocyanin형성에 가장 효과적 이었다. 3. Cytokinin류에서 BA가 kinetin에 비하여 callus生育을 顯著하게 抑制하였고 kinetin 0.2㎎/ℓ에서 anthocyanin형성이 가장 우수하였다. 4. 糖의 종류로는 fructose가 sucrose나 glucose에 비하여 callus增殖에 월등히 높은 효과를 보였고 anthocyanin形成量에는 큰 차이를 보이지 않았다. 5. 日長의 效果에서 anthocyanin形成은 日長이 길어질수록 促進되었으며 callus형성은 日長에 따른 차이를 보이지 않았다. The experiments were conducted to optimize culture conditions for callus growth and anthocyanin formation by in vitro culture of Populus nigra through tests of basal media, inorganic salts, plant growth regulators, sucrose concentrations, sugar and photoperiods. SH media supplemented with 55 g/l sucrose gave the best results in callus and anthocyanin formation. For the effects of plant growth regulators, anthocyanin formation was promoted by treatment with 2.0 ㎎/l 2,4-D. On the other hand, 0.2 ㎎/l kinetin showed the highest activity for anthocyanin synthesis while BA severely suppressed callus growth. Fructose compared with glucose remarkably promoted callus growth but anthocyanin formation showed no difference with sugar type. Anthocyanin pigment accumulation hastened by increasing photoperiod in culture room while callus growth was not affected with photoperiod.

상부 암모니아 사이클을 도입한 드라이아이스 제조 사이클의 해석

이근식 울산대학교 1999 공학연구논문집 Vol.30 No.2

대기 중의 이산화탄소를 감소시키는 방법 중의 하나로 암모니아 냉동사이클을 상부 사이클로 하는 드라이아이스 제조 사이클을 고안하여 해석하였다. 상.하부 각 사이클은 2단 압축을 하며 플래쉬 드럼에서 중간냉각함으로써 압축 각 단에 유입되는 질량유량이 달라 진다. 압축 각 단의 압축동력, 질량유량, 출구온도를 이산화탄소의 응축압력에 따라 구하였다. 본 연구에서는 이산화탄소와 암모니아 사이클의 중간압력들을 계산하기 위하여 종래의 이산화탄소의 응축압력(26 bar)를 사용하였다. 그 결과, 종래의 이산화탄소의 응축압력(26bar)은 최소압축동력과 최적의 이산화탄소의 응축압력의 관점에서 충분히 타당한 압력임을 입증하였다. 본 사이클은 수냉식 응축기를 가진 3단 압축 이산화탄소 제조 사이클의 응축압력(63bar)보다 휠씬 낮은 응축압력(19-26bar)으로 작동되며, 상업적인 드라이아이스 제조 시스템 (260kW/(ton/hr) of dry ice)보다 휠씬 낮은 압축동력이 소요되는 장점이 있다. A dry ice cycle with topping ammonia cascade refrigeration was devised and analyzed as a mean of mitigating the CO₂ concentration in the air. The trends of compression power, mass flow rate, and exit temperature of each compressor were investigated as a function of CO₂ condensing pressure. In this cycle,, the conventional design pressure (26 bar)of CO₂condenser was used to calculate the intermediate pressures of both CO₂-cycle and ammonia-cycle. Results show that the conventional design pressure of CO₂ condenser has an enough validity in point of both minimum compression power and optimum CO₂condensing pressure. The present cascade cycle has advantages in much lower CO₂condensing pressure (19-26bar) than that (63bar)of 3-stage compression system using CO₂as both working fluid and refrigerant and much lower compression power (206-208 kW) in comparison with that (260 kW/(tom/hr) of dry ice) of typical commercial dry ice production system.

地域社會의 情報化 促進方案에 관한 硏究 : 大田·忠淸地域을 中心으로

李根植,金能鎭,鄭相喆 충남대학교 경상대학부설 경영경제연구소 1991 경영논집 Vol.7 No.2

열역학 제2법칙에 의한 이중관 대향류 열교환기의 해석

이근식,남궁규완 울산대학교 1991 공학연구논문집 Vol.22 No.1

비압축성유체를 작동유체로 하고 뜨거운 흐름은 직렬이고 찬 흐름은 병렬로 된 이중관 대항류 열교환기에 대한 성능을 열역학 제1법칙적 관점과 제2관점에서 이론적 및 실험적으로 해석 하였다. 주어진 열교환기 형상과 입구조건에 대하여 펌핑동력에 대한 열교환량 및 엔트로피 생성율을 찬 흐름분율, 유량비열, 입구온도비에 대하여 계산하고 실험치와 비교하였다. 아울러 찬 흐름측을 직렬로 하였을 경우의 값들과도 비교하였다. The performance of the double pipe counterflow heat exchanger which uses an incompressible fluid as a working fluid and is connected in series on the hot side and in parallel on the cold side, was analysed both theoretically and experimentally in the view of 1st and 2nd law of thermodynamics. The ratio of heat transfer rate to pumping power and the rate of entropy generation for the given geometry of the heat exchanger and inlet conditions, were calculated and compared with the experimental results for the cold side fraction, the ratio of capacity rate, and the ratio of inlet temperatures of both sides. In addition, the ratio of heat transfer to pumping power and the rate of entropy generation were compared with those values of the case connected in series on the cold side.

포플라 Callus의 배양환경에 따른 Anthocyanin 생합성

방혜진,이승우,최근원,정인식,설일환 경희대학교 생명자원과학연구원 1997 遺傳工學論文集 Vol.9 No.-

Studies were carried out to investigate the effects of various cultural and environmental conditions on callus growth and anthocyanin biosynthesis of the callus derived from the leaf discs of the Populus hybrid (Populus nigra × Populus maximowiczii cv. Yanghwangchul). Even though the largest amount of anthocyanin was obtained from the calli grown in the vessels illuminated with white fluorescent light, no significant differences in callus growth could be obtained among other vessels illuminated with different light qualities, i.e., red, yellow, blue, green and dark. Callus growth and anthocyanin biosynthesis were promoted by long-day conditions (16-hour photoperiod or longer). The calli grown in Schenk & Hildebrandt (SH) medium continuously (SH→SH) showed the best growth whereas the highest amount of anthocyanin biosynthesis was obtained in the calli grown in SH→SH or SH→White media.

Fin이 부착된 PCM 축열조의 효율성 분석

원성필,이근식 울산대학교 1985 연구논문집 Vol.16 No.2

Fig.1과 같이 PCM(Phase Change Material)蓄熱 system內의 熱傳達을 증가시킬 目的으로 PCM內에 얇은 금속 fin을 설치한 것을 model로 하여 善熱單位의 길이와 폭, fin 두께 및 벽면온도의 변화에 대한 效率的인 蓄熱條件을 熱力學 第一法則과 第二法則을 適用하여 提示하였다. A thermal energy storage using a PCM with fins is shown in Fig.1. Fins are set up increase the heat transfer rate within a PCM. Effective storage contraints have been presented by applying the first and the second law of thermodynamics when various parameters, e.g., the length and width of the storage unit, the thickness of the fin, and the wall temperature, are changed.

Agrobacterium을 이용한 치커리의 형질 전환

김대성,최근원,정인식,이승우 경희대학교식량자원개발연구소 2005 硏究論文集 Vol.24 No.-

본 실험은 치커리 'Radicchio'(Cichorium intybus L.)에서 Agrobacterium을 이용한 형질전환에 영향을 주는 요인들을 적정화하기 위하여 실시되었다. 치커리 'Radicchio'의 자엽절편체를 이용한 kanamycin과 cefotaxime 항생제 감응성 검정 결과 20 mg·L^(-1) 이상의 kanamycin 농도가 형질전환 신초의 선발에 적당하고 200 mg·L^(-1)의 cefotaxime 농도가 절편체 생장에 부정적인 영향을 주지 않으며 배지 내 Agrobacteria를 제거하기에 적절함을 나타내었다. Terpene cyclase 유전자가 재조합된 PILTAB 벡터를 갖는 Agrobacterium tumefaciens LBA4404와의 효과적인 공동배양 기간은 3일간으로 결정되었다. IAA 1.0 mg·L^(-1), BAP 1.0 mg·L^(-1), kanamycin 20 mg·L^(-1) 그리고 cefotaxime 200 mg·L^(-1)를 함유한 선발배지에서 형질전환 된 것으로 여겨지는 신초들이 생산되어 발근을 위해 kanamycin 40 mg·L^(-1)와 cefotaxime 200 mg·L^(-1)이 첨가된 1/2MS 발근배지에 옮겨져 87%의 발근율을 보였다. 발근된 형질전환체들을 대상으로 terpene cyclase 유전자특이 primer를 이용한 PCR 분석이 실시되어 재분화 치커리 내로 1.64 kb 크기의 terpene cyclase 유전자의 성공적인 도입을 확인하였다. This experiment was initiated to optimize factors affecting Agrobacterium-mediated transformation in Cichorium intybus L. cv. Radicchio. The results from the antibiotic sensitivity test for kanamycin and cefotaxime using cotyledon explants of chicory 'Radicchio' suggested that the concentration of kanamycin above 20 mg·L^(-1) might be an appropriate level to make a selection on transgenic shoots possible and 200 mg·L^(-1) of cefotaxime also could be a proper concentration to remove Agrobacteria from the media without any negative effect on explants. The efficient duration for co-cultivation of cotyledon explants with Agrobacterium tumefaciens LBA4404 harboring the recombinant binary vector PILTAB carrying 1.64 kb terpene cyclase gene was decided as 3 days. Putative transgenic shoots were produced on the selection media containing 1.0 mg·L^(-1) IAA, 1.0 mg·L^(-1) BAP, 20 mg·L^(-1) kanamycin, and 200 mg·L^(-1) cefotaxime and transferred to 1/2MS media supplemented with 40 mg·L^(-1) kanamycin and 200 mg·L^(-1) cefotaxime for rooting. The rooting ratio was 63% and putative transgenic plants with roots were obtained. Results from PCR analysis with terpene cyclase gene specific primers confirmed a successful insertion of 1.64 kb terpene cyclase gene into the genomic DNA of the regenerated chicory.

방사선 조사에 의한 흰주 난포의 퇴축과 난포세포의 방사선 감수성

김수일,한승로,조근자,허대영,이영호,조문준,김무강,김원식 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

The aim of this study were to investigate radiation-induced atresia and radiation susceptibility in the rat ovary morphologically. Female rats (Sprague Dawley strain) of 4 weeks old were irradiated with dose of 4 Gy and 8 Gy, and sacrificed at hour 6, 12, and 24 after radiation. The H & E stain, the TUNEL method (ApopTag kit) and transmission electron microscopy (TEM) were used. In light microscopic observation, the number of atresia of ovarian follicles were increased significantly at 6h after irradiation (p<0.01). There was no significant difference between 4 Gy and 8 Gy irradiated groups. In TEM observation, granulosa cells in radio-sensitive follicles were characterized by several structural features including condensation of nuclear chromatin granules, nuclear fragmentation and apoptotic body formation. An apoptotic cell is observed to have been phagocytosed by a normal granulosa cell. Granulosa cells in radio-resistant follicles were characterized by several structural features including nuclear indentation, partial condensation of chromatin granules, mitochondrial swelling, dilatation of RER cisterns, accumulation of dense irregular masses, accumulation of lipid droplets, and increased lysosomal bodies. Number of gap junctions between granulosa cells were decreased, and intercellular space were widen than that of control animals. These findings were prominent at 6h after irradiation and were diminished at 12h and 24h after irradiation. With these results, it was concluded that radiation-induced follicular cell apoptosis and ovarian follicular atresia in rat ovary increased considerably at 6h after irradiation. Further studies are needed to reveal the more extensive differences between radiosensitive and radioresistant follicular granulosa cells.