Tetracycline이 白鼠의 骨成長 및 鑛化作用에 미치는 影饗에 關한 實驗的 硏究

金宗哲 최신의학사 1974 最新醫學 Vol.17 No.7

For the purpose of studying the effect of tetracycline on mineralization and growth, the rats were given a daily dose of 40mg. /kg. /day and 80mg. /kg. /day of tetracycline during the 8th-15th day of gestation. The effect of tetracycline on young rats delivered from adult rats receiving tetracycline had been assessed mainly through studies of body weight, length of tibia, size of mandible and contents of calcium. The latter was determined by atomic absorption spectrophotometry. The results were drawn as follows. 1. Tetracycline had the inhibitory effects on growth and mineralization in rats. 2. The more dosage of tetracycline had the severer inhibitory effects on growth and mineralization in rats. 3. The inhibitory effect on body weight was observed in group 1 (40mg. /kg. /day) during the 1st week after delivery, in group 2 (80mg. /kg. /day) during the 3rd week after delivery. The highest value of depression rate on body weight was 28.7% in group 2 (80mg. /kg. /day) at the 1st day after delivery. 4. The inhibitory effect on growth rate of tibia was observed in group 1 (40mg. /kg. /day) during the 2nd week after delivery, in group 2 (80mg. /kg. /day) during the 3rd week. after 4elivery. The highest value of depression rate on tibia growth was 36. 2% in group 2 (80mg. /kg. /&a.y) at the 1st day after delivery. 5. The inhibitory effect on growth rate of mandible was observed in group 1 (40mg. /kg. /day) during the 1st week after' delivery, in group 2 (80mg. /kg. /day) during the 3rd week after deiivery. 6. The calcium contents on mandible, tibia, anterior teeth and posterior teeth were incraasel in group 1 (40mg. /kg. /day) during the 1st week after delivery, in group 2 (80mg. /kg. /day) during the 4th week after delivery.

대향류형 볼텍스 튜브의 溫度 分離에 관한 實驗 硏究

金鍾喆 충주대 산업과학기술연구소 2000 産業科學論文集 Vol.8 No.-

Every vortex tube is different in geometric condition. Especially, inner diameter of tube and the ratio of length to inner diameter are various, And in each case of geometric conditions, effect of temperature separation is all different. Generally as temperature difference between inlet air and outlet cold air is larger, effect of temperature separation is better. From the experiment, the following conclusive remarks can be proposed. When the inner diameter of the nozzle increases, we can observe that the temperature separation effect is better. And we find the geometry condition of the orifice that makes the temperature separation effect better. And when we use the 60˚ cone, the temperature separation effect is better.

출혈이 동반된 신장 이행세포암종의 방사선학적 소견

김종철 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

Transitional cell carcinoma (TCC) of the urinary tract is usually hypovascular, with no frequent hemorrhagic tendency. The purpose of this study was to evaluate whether this kind of tumor would be diagnosed on preoperative radiologic imaging, through the analysis of radiologic findings of pathologically proven renal TCC with hemorrhage. Of 30 patients with pathologically proven renal TCC during recent five years, five patients of TCC with hemorrhage in whom ultrasonography (US), computed tomography (CT), or magnetic resonance (MR) imaging was performed were included in this study. In addition to excretory urography, CT was performed in three patients, US and CT in one, and MR imaging in one. Compared with pathological findings, radiologic ones were retrospectively evaluated for size, location, echogenecity/density/signal intensity, degree of contrast enhancement of the tumor, and associated findings of hemorrhage or other lesion. Images demonstrated renal TCC with the preservation of the reniform outline of the kidney in all patients. The largest diameter of the tumor ranged from 1.5 cm to 4 cm (mean = 2.5 cm). The location of the tumor was renal pelvis (left : right = 3 : 1) in four patients and right lower pole calyces in one. US showed an isoechoic tumor in one patient, and CT showed minimally enhancing iso- or hypodense tumors with internal or surrounding hyperdense portions in four patients. TI-weighted MR image demonstrated minimally enhancing hypointense masses in the right lower pole calyces and hyperintense fluid in the adjacent dilated pelvis and calyces. Pathology proved hemorrhage in or around the TCC in four patients and in dilated renal pelvis and calyces adjacent to the TCC in one patient of MR imaging. When CT or MR imaging reveals that pelvicalyceal filling defects on excretory urography or retrograde pyelography are minimally enhancing neoplasms with internal or surrounding hyperdense/hyperintense areas, the radiologic diagnosis of the tumor may be rare renal TCC with hemorrhage.

大學敎育課程의 實態와 發展方向에 관한 硏究

김종철,길형석,이종숙,송영경,김병주 덕성여자대학교 고등교육연구소 1992 敎育硏究 Vol.3 No.-

Drill 加工에서 Chip 生成過程과 工具壽命에 關한 硏究

金鍾喆 忠州大學校 1988 한국교통대학교 논문집 Vol.22 No.-

Recently there have been many studies on various drill working with the development of mechanical industry. In this research I examined chip formation and tool life changing cutting condition in cutting working with drilling machine. The results are as follows: 1. In chip formation when the cutting speed is fast and the feed speed is slow, we can get a good result of the surface roughness and chip. but tool life is shorter. 2. In relation between cutting speed and feed speed, the larger is cutting speed than feed speed, the more rapidly increases web wear. 3. In tool life the relation between cutting speed and feed speed is as follows: V=C₁D?? F=C₂D??

切削性과 切削油에 關한 硏究

金鐘喆 忠州大學校 1983 한국교통대학교 논문집 Vol.16 No.2

All technicians hope a high efficience of production and a long tool life when they use a cutting tool. However cutting tools wear out by their crater wear, flank wear or chipping wear. The writer made an experiment on oblique dimension of cutting in oil-off and oil-on to see the wear. The results are as follows; 1. Flank wear and crater wear functioned by their depth of cut and feed speed. 2. Under a cutting condition, crater wear and flank wear increased according to the depth of cut rather than the feed speed. 3. Crater wear was more remarkable than the flank wear in tool wear.

多孔 蒸氣 Diffuser의 길이가 eJector 性能에 미치는 影響에 關하여

金鍾喆 충주대학교 1978 한국교통대학교 논문집 Vol.11 No.1

This paper present, the experimental study of multinozzle steam ejector by using the motive steam pressure of 6.0㎏/㎠ in order to obtain the effect of variations in diffuser parallel length 6 kinds of different parallel part were used. The investigation on the effect of diffuser length on the performance characteristics of ejector is performed by changing the in haled airflow under the constant throat area ratio and motive stea ratio and motive steam pressre.

初期 琺瑯質 우식증의 走査電子顯微鏡的 硏究

金鐘喆 大韓小兒齒科學會 1987 大韓小兒齒科學會誌 Vol.14 No.1

The author examined the early enamel caries in the proximal surface of extracted deciduous teeth with scanning electron microscope. The results are as follows. 1. Surface structure of eary enamel caries of deciduous teeth is different from that of unaffected sound enamel. 2. Typical findings of surface structure examined are as follows; focal hole, micro pore, irregular fissure, decalcification of prism core, exfoliation of enamel surface and granular crystallite. 3. Prismless layers are seen in the enamel surface with in 20μm - 30μm depth of several deciduous teeth.

비조영 복부 전산화 단층 촬영에서 디지털 영상 처리를 이용한 신장 용적 계측에 관한 동물 실험 : 예비 보고 Preliminary Report

김종철 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

To evaluate the usefulness of automatic segmentation and volume measurement of the kidney using newly developed digital image processing on unenhanced abdominal computed tomography(CT) in pigs. Unenhanced abdominal CT scans of two anesthetized four-month-old Landrace pigs were performed with 3-mm slice interval. Both kidneys on CT were extracted by two steps of image processing: (1) automatic segmentation in a single slice using the character of pixel distribution of the kidney, and (2) removal of residual noise using batch processing with folding method. The volume of kidney was determined using information of slice thickness and pixel size. Finally the measured renal volume by this digital image processing method was compared with the actual renal volume obtained by means of three consecutive water displacement measurements on surgically removed specimen of both kidneys. As a result of comparison between mean renal volume of both sides measured by digital image processing (78.3. 67.4cm^(3); right & left respectively) and mean actual renal volume(80, 70cm^(3)), the error was less than 3.7%. The renal volume determined by this digital image processing was almost as same as the actual renal volume. The method used in this study will be clinically applicable to determine renal volume both in normal persons and patients.

급확대 디퓨져에서의 박리제어에 관한 실험적 연구

金鍾喆 충주대 2001 한국교통대학교 논문집 Vol.36 No.1

The aim of using diffuser is that convert dynamic pressure to static pressure.But, if diffusion angle of diffuser is very large, separation is generated.This separation products energy loss and reduces pressure recovery coefficient.To overcome this energy loss vortex flow is put into by vortex generator jet to the tangential direction main pipe. In this study, flow separation and pressure recovery coefficient in two annular diffusers, diffusion angle(2 α) of one is 14˚ and the other is 30˚ are investigated using pressure manometer and hot-wire anemometer.Experimental parameter is velocity ratio(Vjep/Um) 0, 0.5, 1.0, 1.5 and 2.0.Main results obtained through this study are summarized as follows ; 1) In case of diffusion angle 14˚ diffuser, pressure recovery coefficient is improved 16.2% at velocity ratio(Vjep/Um) 2.0, and in case of diffusion angle 30˚ diffuser, pressure recovery coefficient is improved 64.7% at velocity ratio (Vjep/Um) 2.0. 2) Result of velocity distribution experimental, constraint by vortex generator jet of separator is confirmed.