接觸變換에 의한 微分方程式의 解法에 관한 小考

李容斗 成均館大學校 1977 論文集 Vol.24 No.-

In this paper is presented a general method to get the solutions of the ordinary differential equations of first order and higher degree with aids of the contact transfromations when the solutions of the equations of first order and first degree are known.

카드뮴 중독 흰쥐에 대한 Noninvasive Biomarker로서의 요중 Ascorbic Acid에 관한 연구

이용우,김용호,안승주,류재두 THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 1997 Journal of biomedical laboratory sciences Vol.3 No.2

본 연구는 카드뮴의 이용 및 환경오염의 증가로 일어날 수 있는 카드뮴 중독에 대한 새로운 생물학적 지표로서의 요중 ascorbic acid를 평가하기 위하여 실험적으로 중독시킨 Sprague-Dawley종의 흰쥐를 이용하여 요중 ascorbic acid측정, 신장의 조직병리학적 조사 및 생화학적 간 기능 검사를 실시하였다. 측정된 요중 ascorbic acid농도의 전 실험기간 (50일) 평균치는 실험군Ⅰ(카드뮴 100ppm)이 214.0㎎/dl, 실험군Ⅱ(카드뮴 200ppm)가 254.3㎎/dl로 대조군 9.0㎎/dl에 비해 각각 24배 및 28배의 증가를 보였다. 조직병리학적 소견으로는 신장의 근위 세뇨관에서 단백뇨의 원인으로 추정되는 호산성 초자양 물질이 관찰되어 신장의 손상이 있었고, 생화학적 분석에서 실험군Ⅰ에서 AST, ALT의 수치가 대조군의 143㎎/dl, 50㎎/dl에 비해 각각 199㎎/dl, 88㎎/dl, 실험군Ⅱ가 270㎎/dl,226㎎/dl로 나타나 간 기능의 손상이 있었음을 알 수 있었다. 이상의 결과로 실험동물이 카드뮴에 노출됨에 따라 그 아만성 독성으로서 간장 및 신장 기능의 손상이 있었고 또한 요중의 ascorbic acid가 현저하게 증가되어 요중 ascorbic acid가 실험동물의 카드뮴 노출에 대한 noninvasive진단 지표로서 활용될 수 있을 것으로 기대된다. This study was planned to evaluate the urinary ascorbic acid as a new bilolgical marker for the intoxication of cadmium, which could possibly be driven by its increased utilization and environmental pollution. In order to meet this goal, we have performed measurement of urinary ascorbic acid concentration, histopathological examination of the kidney, and biochemical test for the liver function using cadmium-intoxicated rats by oral administration. The average concentrations of urinary ascorbic acid in the CdCl₂-treated rats were 214.0㎎/dl for 100ppm group and 254.3㎎/dl for 200ppm group during experimental period of 50 days. These levels are 24 and 28 times higher than one in the control group (9.0㎎/dl), respectively. Ultrastructural study showed the eosinophilic hyaline cast and focal effacement, fusion in the renal tubules, as well as loss of foot processes on the glomerular epithelial cells. These results suggested that cadmium may be responsible for renal glomerular injury. The blood levels of AST, ALT and LDH in the treated groups (199 IU/I, 88 IU/I, 1190 U/I for the 100 ppm group and 270 IU/I, 226 IU/I, 760 U/I for the 200 ppm group) were higher than ones in the control group(143 IU/I, 50 IU/I, 334 U/I). These results indicated the cadmium induced the damage of liver function. In conclusion, the administration of cadmium showed a remarkable increase of urinary ascorbic acid with renal and hepatic damage. Therefore, it is expected that measurement of urinary ascorbic acid would be an powerful method as a noninvasive biomarker for cadmium intoxication.

고분보존용 항온ㆍ항습 System의 동절기 운전특성

이금배,전용두,고석보,김홍기 公州大學校 工學硏究院 生産技術硏究所 2003 論文集 Vol.11 No.-

본 연구는 여러 가지 문화재 보존영역 중 개방된 고분의 장기보존을 위한 최적 공기 조화 시스템의 개발을 목표로 하여 수행되었다. 고분의 장기보존을 위해서는 고분 내 공기조성, 온ㆍ습도 및 기류환경을 모니터하여 고분내 자연 실내환경의 기초자료를 확보한 수 고분의 주 구성요소인 석재 및 전재의 보조측면에서 문제점을 검토하여 최적 유지환경조건을 정의하고, 이상의 요구조건을 실현할 수 있는 공조시스템의 적용이 필요하다. 본 논문은 이 중 모형고분에 적용된 공조시스템의 동계운전성능에 대하여 소개한다.

수중 가청음에 의한 쏨벵이의 청각능력 : 2. 청각 임계비

이창헌,박용석,문종욱,강창익,김고환,서두옥 제주대학교 해양연구소 1999 해양자원연구소연구보고 Vol.23 No.-

수중 가청음은 어군의 행동 제어와 해양목장화에서 음향 순치에 많이 이용되고 있다. 수중 가청음에 의한 어류반응 해석을 하기 위해서는 물고기의 청각능력을 정확히 파악할 필요가 있으며,오래전부터 여러물고기의 청각능력을 관련된 연구가 수행되었다.

수면확성기의 음향특성에 관한 연구

이창헌,문종욱,박용석,최찬문,서두옥 제주대학교 해양연구소 1998 해양자원연구소연구보고 Vol.22 No.-

To obtain the fundamental data on a surface speaker made to lure fish school by pure sound, three surface speakers were made of moving coil driver units of 75W and 50W respectively. Their frequency characteristic was measured in the range of 200 - 4mHz that could be used in luring fish school. The results of the measurements in air and sea are follows. 1. The input and output wave forms of a surface speaker were similar to each other in measurement frequencies in air. Then sound pressure of a surface speaker made of 75W driver units among them was over 130dB(0dB re 20μ Pa) in the range of 300 - 400Hz maximally. 2. When the surface speaker with 75W driver units emitted the measurement frequencies at sea. Sound pressure classified by the depth of water were over 140dB at 1m and 120dB at 20m(0dB re 1μ Pa) respectively.

P型 α-多孔 SiC. 的光致發光光潽硏究

이기환,김영유,두영뢰,우배매 公州大學校 基礎科學硏究所 1998 自然科學硏究 Vol.7 No.-

The photoluminescence (PL) spectra from p-type a-porous silicon carbides prepared under UV photo-assisted process and under dark-current condition are investigated in detail. Emission bands with peak energies of 2.35, 2.50, 2.70, and 3.43 are resolved. The PL stability in tune and the PL difference arising from different tuning excitation energies are studied. It is found that the PL spectra of the a-porous silicon carbide depend strongly on the preparation conditions for electrochemical etching. The PL spectrum of the sample prepared under photo-assisted process has an enhancement on the lower-energy side of the emission; on the contray, another one under dark-current condition has an enhancement at the higher energy side, and the former stability is better than the latter one, and the latter PL intensity decreases with the increase of the time in the air. The reasons about these differences are discussed.

가청수중음에 의한 넙치의 행동에 관한 기초적 연구 : 1.육상수조 양식장내의 환경소음

이유철,이창헌,최찬문,박용석,서두옥 제주대학교 해양연구소 1997 해양자원연구소연구보고 Vol.21 No.-

A fundamental experiment was carried out to confirm the behaviour of Bastard halibut Paralichthys olivaceus to audible underwater sound in a breeding ground around the coast of Cheju Island. To find characteristics of breeding water tank and experiment water tank. ambient noise, undcrwater noise and feeding sound of fish were measured and analyzied respectively. The results of measurement are as follows: 1. The maximum sound pressure level of ambient noise in breeding water tank was 81dB. average maximum sound level of underwater noise was 81dB at 120Hz. 2. The maximum sound pressure level of ambient noise in experiment water tank was 76dB and underwater noise was 84.2dB at 130Hz. 3. The maximum sound pressure level of feeding sound was 85dB at 120Hz.

SLAP Ⅱ 병변의 진단을 위한 관절 조영 자기 공명 영상에서 견관절 위치에 따른 비교

이영수,신동배,박수진,김진용,김희상,하두회 대한견.주관절학회 2000 大韓肩.주關節學會誌 Vol.3 No.2

고추, 포도 및 사과에서 분리한 탄저병균(Colletotrichum gloeosporioides)의 특징과 병원학적 연구

李斗珩,李龍範 서울市立大學校 1989 論文集 Vol.23 No.-

Three species of Colletotrichum Corda and Glomerella cingulata(Stonem). Spauld. & v.Schr. known to cause ripe fruit rots of apple, peach and pepper in Korea are compared with respect to culture characteristics, morphology, temperature reactions and pathogenicity determined by field collection and artificial inoculation. The following 4 species and 3 strains of anthracnose fungi reconized : C. coccodes (Wallr). Hughes, C. dematium (Pers. ex Fr.)Grove, C. gloeosporioides(Penz.) Sacc. G, chromogenic, and non-chromogenic strain and G. cingulata. The characteristic features of these organisms are discussed and on the evidence available it is found desirable to designate a new form of C. gloeosporioides or new species of Colletotrichum. It appears that the differences in virulence is not only among the different species of Colletotrichum and G. cingulata but also between isolates of the same species. C. dematium, G. gloeosporioides and G. cingulata are detected in seed samples of red pepper (Capsicum annuum) and C. gloeosporioides are the predominant species in seeds of red pepper which are naturally infected with anthracnose in field conditions. Plating of seed components showed that three species of anthracnose fungi are detected from seed coat, endosperm and plumule bud. C. dematium, C. gloeosporioides and G. cingulata caused seed rot, damping-off and seedling blight. In the effect of some fungicides to C. dematium and C. gloeosporioides on red pepper, Difolatan was the most effective to the fruit rot followed by Orthocide and Phaltan.

수중 가청음에 대한 멸치 어군의 행동 반응

이창헌,문종욱,박용석,최찬문,서두옥 제주대학교 해양연구소 1998 해양자원연구소연구보고 Vol.22 No.-

A field experiment was carried out to confirm the effect of underwater sound on the luring of fish school using a surface speaker at the coast of Cheju Island. Underwater sounds that were emitted for the luring of fish school were the pure sound of which frequencies were 200Hz and 300Hz. 1. The sound pressure level of 100Hz. 200Hz. 300Hz. 500Hz and 1000Hz classified by the depth of water at sea were 95dB. 100dB. l00dB 80dB and 60dB at 1m. 90dB. 95dB. 88dB. 70dB and 45dB at 10m. 87dB, 90dB. 82dB. 65dB and 42dB at 20m respectively. 2. The effect of the emitted pure sound of 200Hz and 300Hz was remarkable for luring of fish school in about 30 minutes after sound emission. Then Sound pressure was 120 - 130dB. The lured fish school was the shoal of anchovy 3. The fact that anchovy school geathered at 200Hz and 300Hz suggested that this fish school did not show sensitive response to the change of frequencies.