인공모래 부산물 재활용 방안

김경남,신대용,이현종 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

인공모래 제조시 부산물로 발생하는 석분슬러지에 의한 환경문제와 폐기되는 자원의 활용문제를 해결하기 위하여 석분슬러지와 점토 및 폐유리분말을 이용하여 900∼1,100℃로 소성하여 세라믹스 건자재를 제조하였다. 석분 슬러지는 평균입경 16.3㎛, 비표면적 0.42㎡/g, 화학조성은 CaO 46.43wt%, SiO_2, MgO 와 Al_2O_3가 7.83 wt% , 6.17 wt% 및 3.13 wt%이며, 주결정상은 calcite (CaCO_3)와 dolomite (CaMg(CO_3)_2)로서 약 800℃에서 CaCO_3나 CaMg(CO_3)_2의 열분해에 의한 32.52wt% 의 강열감량을 나타내었다. 석분슬러지와 점토를 이용한 시편(No. 1, 4, 7, 10 및 13)은 점토의 첨가량과 소성온도가 증가함에 따라 시편의 부피비중 및 압축강도는 증가하였으나 기공률과 흡수율은 감소하여 No. 1, 4, 및 7 시편은 부피비중 1.78∼1.98, 기공률 6.4∼12.5%, 흡수율 10.3∼12.7%, 압축강도 264∼370kgf/㎠을 나타내었다. 폐유리분말을 첨가한 시편(No. 2, 5, 6, 8, 9, 10 및 12)의 부피비중과 압축강도는 1.91∼2.63 및 213∼895kgf/㎠로서 폐유리분말의 첨가가 시편의 소결성과 압축강도의 향상에 기여하여 세라믹스 건자재로 사용이 가능하였다. The utilization of waste stone powder sludge produced secondarily from artificial sand plants of Ssangyoung resource development (Co.) and general waste, as was classified, became very important to solve the environmental problem and waste materials recycle. In the chemical composition of stone powder sludge, the amount of CaO was 46.43wt%, SiO_2, MgO and Al_2O_3 were 7.83 wt% 6.17 wt% and 3.13 wt%, respectively. The mean average particle size was 16.3㎛ and specific surface area was 0.42㎡/g. Main crystal phases were calcite (CaCO_3) and dolomite (CaMg(CO_3)_2) and ignition loss was 32.52wt% because of decomposition of CaCO_3 or CaMg(CO_3)_2. Specimens were fabricated by mixing the waste stone powder sludge, low-grade clay, waste glass powder and sintering at 900∼1,100℃ for 2 hours. The density and compressive strength of specimen increased with increasing the sintering temperature and the amount of clay. The specimen showed the bulk density of 1.78∼1.98, porosity of 6.4∼12.5%, water absorption 10.3∼12.7% and compressive strength of 264∼370 kgf/㎠. Those of the specimen heated at 1,050℃ increased with increasing the added amount of waste glass powder, bulk density was 1.91∼2.63 and compressive strength was 213∼895 kgf/㎠. Therefore, the waste stone powder sludge can be used as a constructional materials.

Budd-Chiari 증후군 : 1례 보고 A Case Report

김승현,오연희,이현경,이성우,서정욱 동국대학교 경주대학 1997 東國論集 Vol.16 No.1

하대정맥의 막성폐쇄로 인한 Budd-Chiari 증후군은 비교적 드문 질환으로 알려져 있다. 저자들은 우상복부 동통을 주소로 내원한 환자에게 방사선학적 검사와 임상적으로 확진된 하대정맥의 막성폐쇄에 의한 Budd-Chiari 증후군 1례를 경험하였기에 문헌고찰과 함께 보고 하고자한다. The Budd-Chiari syndrome is a rare, often fatal illness resulting from hepatic venous outflow occlusion. It occurs secondary to intrinsic vascular thrombosis, tumor invasion, or rarely a congenital web. We report a case of primary Budd-Chiari syndrome with membranous obstruction of inferior vena cava, with a brief review of literature.

窒素, 燐酸 및 加里의 施肥水準이 藥用作物 仙鶴草(Agrimonia pilosa L.)의 生育 및 收量에 미치는 影響

김현경,황필성,이용호,김기영,정대수 東亞大學校 大學院 2000 大學院論文集 Vol.25 No.-

This study was carried out to determine the effect of various fertilizer levels on the growth and yield of Agrimony. this experiment was conducted for 2years from 1998 to 1999 in Medicinal Plant Experiment Station, Kyungnam ARES. The results obtainned were summarized as follows : 1. The growth characteristics such as plant height, tillers and leaf numbers were more increased at 22-10-10 plot than of other fertilizer levels. 2. Variations of percent flowering of Agrimonia pilosa L. treated with different fertilizer levels were more increased at 22-10-10 plot than of other fertilizer levels. 3. Yield per 10a of Agrimonia pilosa L., Fresh weight was 1,500kg in 22-10-10 plot, and 243kg in non-treatment plot. The dry weight was 736kg in 22-10-10 plot, and 96kg in non-treatment plot. Yield of Seed and Fruit following to different application levels was highest at the fertilizing plot of N, P2O5, K2O=22-10-10.

植物 生長調整劑의 處理가 水稻幼苗의 蛋白質 含量 및 酵素 活性에 미치는 影響

金度勳,金賢勍,鄭大守 東亞大學校 1996 東亞論叢 Vol.33 No.-

A study was carried out to investigate the effect of growth regular on protein content, PAL and peroxidase activity in rice seedling plants, Akibare, a Japonica type variety. ABA(0.1, 1, 10ppm), 2.4-D(10, 100, 1000ppm), and GA(0.05, 0.5, 5ppm) were respectively treated for 5 days to the nee seedling plants which were grown for 20 days. The results were summarized as follows. In stems, the protein content showed the highest value in the plot treated with GA for 5 days, although ABA and 2.4-D treated plots showed no significant differences compared with the control. PAL activity in the plot treated with GA for 5 days and in the plot treated with 2.4-D for 10 days were respectively higher than control. On the contrary, it was low in the plot treated with ABA. PAL activity in roots was respectively higher in the plots treated with GA for 5days and 2.4-D for 10 darts than the control. According to increment of days seedling growth, peroxidase activity was respectively maintained in the plot treated with ABA, 2.4-D, and GA, although it was decreased in the control.

實驗水路에서 數値解析法에 의한 跳水에 관한 硏究

金成原,趙顯景,趙廷錫 대구대학교 과학기술연구소 1997 科學技術硏究 Vol.4 No.2

In this study, Boussinesq equations describing on dimensional unsteady, rapidly varied flows are integrated numerically to simulate both the sub- and supercritical flows and the formation of a hydraulic jump in a rectangular channel having a small bottom slope. for this purpose MacCormack (second -order accurate in space and time) and two-four (second -order accurate in time and fourth-order in space)explicit finite-difference schemes are used to solve the governing equations subject to specified end conditions until a steady state reached. Complete test results for a range of Froude numbers are presented that may be used by other researchers for the verification of mathematical models. A comparison of the computed and measured results shows that it is satisfactory for the fourth-order finite-difference schemealthough the second-order scheme does not accurately predict the location of the jump. These simulations show that the Boussinesq terms have little effect in determining the location of the hydraulic jump.

Hydroa Vacciniforme의 1예

김홍직,이종석,김영근,현경준 순천향대학교 1989 논문집 Vol.12 No.3

Hydroa vacciniforme is a rare, light sensitive dermatitis characterized by discrete vesicles followed by varioliform scar formation, which was first described by Bazin on 1862. Our case was a 10-years-old girl who had umblicated vesicles, crusts, varioliform scars on both cheeks, nose, dorsum of hands in symmetrical distribution with itching sensation, which had used to recur in every summer since last five years ago. Histologic examination showed necrosis and multilocular bullae due to reticular degeneration in the epidermis, extravasation of red blood cell and lymphohistiocytic infiltration in the dermis. On urine examination, porphyrin was negative. Diagnosis was established by clinical characteristics and laboratory findins and histologic pictures.

p-Anisaldehyde가 조골세포 분화에 미치는 영향

김경민 ․ 이도원 ․ 김현준 ․ 김아랑 ․ 장원구 대구대학교 산업기술연구소 2018 産業技術硏究 Vol.29 No.2

p-Anisaldehyde is a natural fragrance extracted from Pimpinella anisum L., and used as a preservative. This study examined the effect of p-anisaldehyde on osteoblast differentiation. First, cytotoxicity tests were carried out after examining the concentrations that did not show toxicity to the cells. The expression of osteoblast differentiation marker gene was confirmed by RT-PCR and was not effective in the treatment with p-anisaldehyde alone. However, p-anisaldehyde decreased the expression levels of inhibitor of differentiation-1 (Id1), distalless related homeobox (Dlx5), and runt-related transcription factor 2 (Runx2), which are osteogenic differentiation marker genes, which are increased in osteogenic condition. alkaline phosphatase (ALP) activity was also confirmed by ALP staining that p-anisaldehyde reduced ALP activity. These results show that p-anisaldehyde is effective in reducing osteoblast differentiation.

인공지능형 학습 엔진의 설계

김현경 한신대학교 정보과학연구소 2000 한신정보대학교 정보과학연구소 Vol.- No.2

施肥條件이 사탕무의 生育과 Betacyanin 含量에 미치는 影響

金度勳,朴賢眞,金賢勍,鄭大守 東亞大學校生命資源科學大學附設 農業資原硏究所 1996 農業生命資援硏究 Vol.5 No.1

사탕무의 生育과 betacyanin 含量의 變化에 대한 施肥條件의 影響을 알아보기 위하여 室素 0, 10, 15 및 20㎏/10a와 加里 0, 10, 15 및 20㎏/10a 處理하여 試驗한 結果는 다음과 같다. 草長과 葉數는 室素 15㎏/10a 處理區까지는 增加되었으나, 20㎏/10a 處理區에서는 오히려 減少되었으며, 根直徑과 根長도 室素 施用量의 增加에 따른 有意的인 差異가 認定되었다. 그리고 根重은 無處理區에 비해 室素 處理區에서 增加되었으나, 室素 處理區間에는 큰 差異를 나타내지 않았다. Betacyanin 含量은 室素 15㎏/10a와 加里 20㎏/10a 處理區에서 0.126%로 가장 높았고, 生育段階別로는 파종후 110日에 가장 높은 含量을 나타내었다. These experiments were carried out to investigate the effect of nitrogen and potassium application on growth and betacyanin content of sugar beet. The experiments were respectively treated with 0, 10, 15 or 20㎏/10a nitrogen and 0, 10, 15 or 20㎏/10a of postassium, and the results were summarized as fellows. Plant height and number of leaves were increased by 15㎏/10a of nitrogen, otherwise; it was decreased by 20㎏/10a of nitrogen. There were significant differences root diameter and root length by increament of nitrogen application. Root weight was progressively increased by nitrogen treatments compared to the control, although there was no significant differences among the amount of nitrogen treatments. Betacyanin content was high 0.126% in the plot treated with 15㎏/10a of nitrogen and 20㎏/10a of potassium respectively. For the growth stage the corresponding value showed the highest level at the 110th day after seeding.

폴리카보네이트 브라켓 부착 시 결합강도 증진을 위한 표면처리 효과

김석필,김년경,이현정,황현식 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.5

본 연구는 폴리카보네이트 브라켓 부착 시 표면처리가 결합강도를 증진시키는지 알아보고자 시행되었다. 소의 하악 중절치를 포매하여 만든 100개의 시편에 광중합형 레진 접착제를 이용하여 폴리카보네이트 브라켓(Alice, 광명 데이콤, 대한민국)을 부착하였다. 대조군의 경우, 표면처리 없이 부착한 반면, 실험군의 경우 샌드블라스팅 처리한 경우, plastic conditioner 처리하여 부착한 경우, 그리고 샌드블라스팅과 함께 plastic conditioner 처리한 경우로 구분하여 접착하였다. 만능시험기를 이용하여 전단결합강도를 측정하고 파절양상을 비교 분석한 결과, plastic conditioner나 샌드블라스팅으로 표면처리를 시행한 경우 표면처리를 시행하지 않은 경우에 비해 높은 결합강도를 보였다 (p<0.001). 샌드블라스팅과 Plastic conditioner를 모두 처리한 경우는 샌드블라스팅만이나 plastic conditioner만 처리한 경우보다 높은 결합강도를 보였으며, 특히 샌드블라스팅만 처리한 경우에 비해서는 통계적 유의차를 보였다 (p<0.05). 이상의 연구결과는 폴리카보네이트 브라켓 부착 시 결합강도 증진을 위해서 베이스의 표면처리가 필요하며 샌드블라스팅 후 plastic conditioner 도포가 가장 효과적임을 보여주었다. Objective: The purpose of this study was to evaluate whether the bond strength of polycarbonate brackets can be increased through surface treatment. Methods: One hundred polycarbonate brackets (Alice) were bonded to bovine incisors with light-cured adhesive. The bracket bases were treated with one of three methods; sandblasting, plastic conditioner application, and combined treatment with sandblasting and plastic conditioner. The brackets without any surface treatment served as the control. The shear bond strength was tested with a universal testing machine, and failure pattern was assessed with the adhesive remnant index. Results: The shear bond strength in all experimental groups was higher than that of the control group (p<0.001). The group treated with plastic conditioner after sandblasting showed statistically higher shear bond strength than the sandblasting only group (p<0.05). The group treated with plastic conditioner after sandblasting showed higher shear bond strength than plastic conditioner only group, but the difference was not statistically significant. Conclusion: The above results suggest that the surface treatments of polycarbonate bracket is mandatory to improve bond strength, and the most effective method is an application of plastic conditioner after sandblasting.