착색사출성형품에서 안료 및 성형조건이 수축에 미치는 영향

정영득,한성렬 釜慶大學校 1999 釜慶大學校 論文集 Vol.4 No.1

The pigments used for coloring of plastic parts influence considerably on the parts quality such as precision, appearance and strength. In this research, we explored the effects of injection molding condition and pigment's material properties on the shrinkage in the injection molded PP(polypropylene) parts. Injection molding experiments were conducted to collect data that were used to relations between parts qualities and injection condition such as melt temperature, injection pressure and holding pressure with various pigment. The results for injection conditions show that shrinkage was increased according to increasing melt temperature and decreased according to increasing injection pressure and holding pressure. And the results for pigments show that shrinkage in case of adding organic pigments was shown larger that inorganic pigments and red among all pigments were shown largest shrinkage in all case.

여수국가산업단지 인근 지역 대기오염물질 농도에 영향을 미치는 요인분석

김민영,변정훈,이영훈,이건영,한지은,이예림,임지현,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

Eight monitoring stations in the Yeosu National Industrial Complex will determine the concentration of air pollutants measured every hour in 2019, analyze what factors affect them, and how they correlate with the air pollutant measurements. Six air pollutants (SO2, NO2, O3, CO, PM-10 and PM-2.5) measured at eight monitoring stations around Yeosu National Industrial Complex (Seogang-dong, Wolnae-dong, Munsu-dong, Yeocheon-dong, Deokchung-dong, Hwayang-myeon, Yulchon-myeon, Samil-dong) the measurement data for each hour of the year were downloaded to analyze the concentration by weather condition, time zone, season, separation distance from Yeosu Industrial Complex, and separation distance from Gwangyang Industrial Complex. SO2, NO2, and CO concentrations were significantly higher in winter, significantly lower in summer, and O3, PM-10, and PM-2.5 concentrations were significantly higher in spring. SO2, CO, PM-10, and PM-2.5 concentrations were significantly higher between 10 a.m. and 12 p.m., NO2 concentrations were significantly higher between 7 a.m. and 9 a.m., and O3 concentrations were significantly higher between 13 p.m. and 15 p.m.(p<0.001). The concentration of air pollutants (SO2, NO2, CO, PM-10, PM-2.5) excluding O3 was found to have a negative (-) correlation with weather condition, and in the case of O3, it was found to have a positive (+) correlation with PM-10, PM-2.5, temperature and wind speed. It was confirmed that the concentration of air pollutants emitted from the Yeosu National Industrial Complex differs depending on the season, time and distance to the industrial complex. This study aims to establish measures to minimize health damage to residents living relatively close to the industrial complex and contribute to the establishment of management and response measures according to the properties of substances to reduce the concentration of air pollutants in the future.

잣버섯 (Lentinus Iepideus DGUM 25050)의 균사생육을 위한 배지조성의 최적화

정광교,한영환 동국대학교 경주대학 1997 東國論集 Vol.16 No.2

The fruiting body of Lentinus lepideus has been used as an edible mushroom, which has good taste, typical pine flavor and medicinal components for immunostimulation and antitumor activity. In this study, the culture condition and medium composition of L. lepideus DGUM 25050 isolated were optimized for higher mycelial production. The optimal temperature and pH for mycelial culture were 30℃ and pH 5.0, respectively. Among the complex media tested, yeast-malt extract was most favorable for stimulating mycelial growth of L. lepideus. When the Czapek-Dox medium was used as a minimal medium for mycelial culture, starch of polysaccharide was very excellent and both lactose of dissacharide and xylitol of monosaccharose were prominent as a sole source of carbon and energy. As a source of nitrogen, organic nitrogen complex was better than inorganic one and organic soytone was best. When Na_2HPO_4 as a phosphorus source and p-amino benzoic acid as a vitamin were supplemented to the minimal medium, mycelial growth was enhanced. The optimal C/N ratio was 6.0 and stimulated a favorable growth of L. lepideus, when 3.0% of starch and 0.5% of soytone were added to the medium. The optimized medium for mycelial growth of L. lepideus DGUM 25050 was determined and named as LLM, of which composition was as follows: starch 3.0%, malt extract 1.2%, soytone 0.5%, Na2HPO4 0.72%, formic acid 0.1%, ethyl alcohol 0.1%, p-aminobenzoic 0.5 ㎎/l. When the mycelia were cultivated for 15 days, 9.2 g/ℓ of dry weight in LLM broth was higher than 6.8 g/ℓ in the medium used generally for mycelial culture of L. lepideus.

동결속도제어에 의한 동결건조기 성능개선 및 동결건조품의 물리적 특성에 관한 연구

김정한,신영우,김민용,박기원,강정길 여수대학교 1998 論文集 Vol.12 No.2

It is essential to establish optimum operating condition in order to decrease freeze drying time and energy cost on freez-drying process. In this study freezing point, thermal condutivity and permeability of vapour on freeze-drying process of coffee solution were measured. The results of abtained were summarized as follows: 1) thermal conductivity were not affected by freezing rate but were increased with increasing concentration of coffee solution 2) permeability of vapour was increased with decreasing freezing rate and concentration of coffee solution These result suggested that freezing temperature of freeze-drying material must be determined through measuring freezing point of material for the purpose of saving energy cost and ahortening freezing time 1) thermal conductivity depend on solids porosity and was not concerned with size and shape of pore 2) permiability decrease with lowering freezing temperature beacuse radius of freeze drying layer was smaller and permiability decrease with higher concentration because of porosity was decreased

제대혈 분리방법의 차이에 따른 단핵구 및 조혈모세포의 수득 효과에 관한 비교연구

박정숙,이영호,최안홍,노신애,김태겸,한진영 대한조혈모세포이식학회 1998 대한조혈모세포이식학회지 Vol.3 No.1

연구배경 : 최근에 보고된 변형적 Ficoll-Hypaque 방법을 이용한 제대혈 분리방법이 지금까지의 고식적 Ficoll-Hypaque 분리방법에 비하여 조혈모세포의 수득효과면에서 얼마나 차이가 있는지 또한 비교적 수득효과가 크다고 알려져 있는 3% gelatin을 이용한 분리방법에 비하여 얼마나 효과적인지를 알아보고, 제대혈 분리방법의 차이에 따라 단핵구와 조혈모세포 사이에 어떤 상관관계가 있는지 알아보기 위하여 본 연구를 시행하였다. 방법: 21명의 건강한 산모로부터 정상 질식 및 제왕절개 분만 후 제대정맥에서 해파린 처리한 주사기를 사용하여 제대혈을 채취하였다 채취한 제대혈은 동일하게 3개월 시험관에 나누어 실온에서 24시간 이내에 고식적 Ficoll-Hypaque분리법, modified Ficoll-Hypaque 분리법, 3% gelatin 분리법을 이용하여 각각 단핵구 분리를 시도하였으며 이들의 단핵구수 및 생존률, CD34 양성세포수, 집락수를 측정 비교 하였다. 또 상관분석을 이용하여 단핵구수, CD34양성세포수와 CFU-GM집락수 사이의 상관관계를 알아보았다. 결과: 1) 세포 생존률은 고식적 Ficoll-Hypaque 분리법, 변형적 Ficoll-Hypaque 분리법, 3% gelatin 분리법 사이레 통계적 차이가 없었다. 2) 단핵구수는 3% gelatin으로 분리했을 때가 4.56±1.86 (×10^(6)/mL)로 수득효과가 가장 높았으며 (P=0.0001), Ficoll-Hypaque으로 분리했을때는 각각 1.54±0.06(×10^(6)/mL), 1.36±0.67(×10^(6)/mL)로서 고식적 방법과 변형적 방법 차이에 통계적 차이가 없었다. 3) CD34 양성세포수는 3%gelatin으로 분리했을 때가 6.08±3.99(×10⁴/mL)로 수득효과가 가장 높았으며 (P=0.0001), Ficoll-Hypaque으로 분리했을 때는 각각 2.18±2.17(×10⁴/mL), 2.24±1.63(×10⁴mL)로서 고식적 방법과 변형적 방법사이에 통계적 차이가 없었다. 4) CFU-GM 집락수는 3% gelatin으로 분리했을 때가 15.72±8.93(×10³/mL)로 수득효과가 가장 높았으며 (P=0.0002), Ficoll-Hypaque으로 분리했을 때는 각각 3.12±1.45(×10³mL), 2.35±0.82(×10³/mL)로서 고식적 방법과 변형적 방법 사이에 통계적 차이가 없었다, 5) 제대혈 고식적 Ficoll-Hypaque 방법으로 분리하였던 경우는 단핵구수와 CFU-GM집락수 사이에 상관관계가 없었으며CD34 양성세포수만 CFU-GM집락수와 상관관계가 있었다. (r=0.57). 또 변형적 Ficoll-Hypaque 방법에 의하여 분리하였던 경우는 단핵구수나 CD34 양성세포수 모두가 CFU-GM 집락수와 상관관계가 없었다. 그러나 제대혈을 3% gelatin법으로 분리하였던 경우는 CFU-GM집락수 가 단핵구수 (r=0.88) 및 CD34양성세포수(r=0.86)양자 모두와 상관관계가 있었다. 결론 : 3%gelatin을 이용하여 제대혈을 분리하는 것이 단핵구 및 조세모세포의 수득효과면에서 가장 효과적이었다. 한편 변형적 Ficoll-Hypaque 분리법이 고식적 Ficoll-Hypaque 분리법보다 시간과 경비면에서 비효율적이면서 수득효과도 높지 못하였다. 또 제대혈 분리법의 차이에 따라 단핵구나 CD34 양성세포와 VFU-GM사이에 상관관계에 차이가 있었으며, 실제로 제대혈이식 후에 생착 여부를 예측할 수 있는 인자가 제대혈 분리법의 차이에 따라 달라지는지에 관해서 보다 많은 임상적 연구가 필요할 것으로 사료된다. Background : Cord blood banking for stem cell transplantation requires volume reduction and red cell depletion for cost effective storage. To determine which technique could minimize the loss of progenitor cells during cord blood processing, we compared the efficacy of cord blood separating methods which were conventional Ficoll-Hypaque method, modified Ficoll-Hypaque method, and 3% gelatin method. Methods : Twenty-one cord blood samples were obtained with heparinized syringes from the umbilical vein following delivery. Three aliquots of each 20mL cord blood were stored at room temperature and processed by 3 different techniques within 24 hours after collection. We compared mononuclear cells(MNCs) counts and their viability, CD34+ cells counts, and CFU-GMs counts and also observed their correlations among three techniques. Results : 1) The yield of MNCs or CD34+ cells was highest in the cord blood processed with 3% gelatin method than conventional or modified Ficoll-Hypaque method(P=0.0001). 2) There were no significant difference in the yield of MNCs and CD34+ cells between conventional and modified Ficoll-Hypaque method. 3) Both MNCs counts (r=0.800) and CD34+ cells counts (r=0.86) were significantly correlated with CFU-GM counts in the cord blood processed with 3% gelatin method. 4) CD34+ cells counts were significantly correlated with CFU-GM counts in the cord blood processed with conventional Ficoll-Hypaque method (r=0.57), but MNC counts were not. 5) Both MNC counts and CD34+ cell counts were not correlated with CFU-GM counts in the cord blood processed with modified Ficoll-Hypaque method. Conclusion : Cord blood separation with 3% gelatin method could provide better yield of progenitor cells than with FICOLL_Hypaque methods. And between two Ficoll-Hypaque methods, modified method is more laborsome but not better in terms of clonogenic potential than conventional method.

기관골 신생증 1예

오영상,이은우,정종혁,문승원,김수현,김동한,양혁승,박정환,박경옥,강성수,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Tracheobronchopathia osteoplastica is a rare disorder of unknown cause characterized by the projection of numerous bony or cartilaginous submucosal nodules into the tracheobronchial lumen with sparing of the posterior membranous portion of tracheobronchial tree. In the past, most of the cases were diagnosed as secondary finding at autopsy. Nowaday, the key component of the evaluation is flexible fiberoptic laryngoscopy and bronchoscopy, which typically demonstrates irregular spicules of subrnucosal bone and cartilage projecting into the tracheobronchial lumen and causing various degrees of airway obstruction. A 45 years old man was visited Sunchon St. Carollo hospital due to discomfort on throat. We saw several nodules just below vocal cord via laryngoscope. The computed tomography revealed multiple small calcified nqdules on trachea and both main bronchi. Pathologic finding of bronchoscopic biopsy showed abnormal proliferation of bony and cartilagious nodules in the tracheal submucosa. These fingdings were consistent with tracheobronchopathia osteoplastica. We report here on a case of tracheobronchopathia osteoplastica with review of literature.

S.D. Rats를 이용 1, 1-Dichloro-1-fluoroethane의 아민성 흡입독성 연구

김현영,이성배,임철홍,김철우,점용현,한정희,전윤석,최수영,강대봉,이용묵 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.1

There were no specific effects for test materials on Sprague-Dawley (S.D.) rats in clinical symptoms, amounts of food intakes, weight changes, laboratory findings, and pathology after whole body l, l-Dichloro-1 -fluoroethane (used as coolant, metal cleaner and solvents) exposure(0, 1,500, 3,000, and 6,000 ppm) for 13 weeks (6 hour/day, 5 days/week). However, the loss of capillary vessels in eyeball (pupil) was observed in a female rat among 6,000 ppm group. Though there was a tendency for MCHC (Mean Corpuscular Hemoglobin Concentration) in rat to be decreased (p<0.05), it was not regarded as abnormal because the values were within normal limits. In asthma-stimulation related evaluations, there was also a tendency for inflammatory cell counts in bronchoalveolar lavages to be increased. But it had no statistical significance, and also no dependency on sex and the exposed concentration. Based on this result, the non observed effect level (NOEL) induced by 1, 1-Dichloro-l -fluoroethene inhalation was evaluated in groups with 3,000 ppm below (S .D. Rats, 13 weeks). Finally, it was concluded that the short term exposal of 1, 1-Dichloro-l-fluoroethane is not considered as a asthma stimulant by inhalation despite of some study limitations such as test animals use and short-term exposure .

Rifampicin에 의한 것으로 추정되는 위막성 대장염1예

김수현,이은우,정종혁,문승현,김동한,양혁승,오영상,김호동,김도현,박혁,박정환,박경옥,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Pseudomembranous colitis, caused by altering the normal colonic flora and allowing the multiplication of Clostridium difficile, is an deleterious adverse effect of antibiotics. But it is rarely reported by rifampicin. Rifampicin is one of the first line drug in the treatment of tuberculosis and many patients are exposed to its potential adverse effects. We experienced a patient that had abdominal discomfort and hematochezia due to pseudomembranous colitis after receiving antituberculous medication, and which was probably caused by rifampicin. A 82 years old man was admitted with abdominal discomfort and hematochezia for one week. On the past history he had been diagnosed as endobronchial tuberculosis about 4 months ago. Colonoscopy revealed multiple discrete whitish mucosal lesion on rectosigmoid colon, and histologic findings were consistent with pseudomembranous colitis. The antituberculous agents were discontinued and vancomycin was administered. The patient's symptoms were resolved within several days. There was no recurrence after reinstitution of the antituberculous agents excluding rifampicin. We report here on a case of pseudomembranous colitis probably due to rifampicin.

BLDC 모터를 이용한 PV 양수 펌프 시스템

최성호,조정민,전기영,김성남,성낙규,김용주,한경희 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

In this paper, we adapted BLDC motor to PV water pumping systems to maintain high efficiency in the wide speed area. Also to design confidence, we adapted the vector control that drive the maximum torque at each speed limit. We designed optimal gain value of current, speed and pressure PI controller. Inverter gate pulse used Space Vector PWM to reduce torque pulsation of BLDC motor. Finally it was improve general matters of high water storage tank method by direct water supply pumping method.

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.