새로운 무기 응집제 개발에 따른 특성

최성우,우성훈,윤철종,곽명화,서향미,박승조 동아대학교 환경문제연구소 2000 硏究報告 Vol.23 No.1

This study has carried out the coagulation tests for tannery wastewater including high-level suspended solids and organic matters to determine the optimum pH and coagulant dosage and to characterize several coagulants for coagulation. In case of optimum pH range test, we know that multi-coagulants are not only cost-effective but also applicable from acidic pH range to alkaline pH range widely, while single-coagulant are useful in limited pH range. Removal efficiency for using of the multi-coagulants appeared more efficient than that of single-coagulant. Especially, sulfates(alum-ferric sulfate : AFS & alum-magnesium sulfate : AMS) are more effective than chlorides (alum-ferric chloride : AFC & alum-magnesium chloride AMC). In comparison of residual turbidity related to settling time between alum and alum-ferric sulfate-magnesium sulfate(AFM), it took to 40 minutes using of alum but 5 minutes using of alum-ferric sulfate-magnesium sulfate(AFM) until constant residual turbidity are reached.

호기성 미생물을 이용한 크롬의 생물학적 환원

최성우,이봉섭,곽명화,윤철종,박승조 동아대학교 환경문제연구소 2001 硏究報告 Vol.24 No.2

Chromium occurs naturally in the earth's crust as well as in air, surface, and ground water. However, chromium is released to the environment in much larger amounts as a result of human activities. Hexavalent chromium, Cr(Ⅵ), is very soluble in water in natural environment and very toxic, carcinogenic, and mutagenic in animal and man. On the other hand trivalent chromium, Cr(Ⅲ), is less toxic and less soluble and thus is a lesser problem. This study has been carried out in order to reduce toxicity of Cr(Ⅵ) by an Escherichia coli strain. After adding E. Coli., the results were obtained from concentration of total Cr, Cr(Ⅵ). Cr(Ⅲ), pH, turbidity, and VSS in aerobic condition was summarized as follows : After 48hr aerobic condition in experiment of synthetic wastewater, the reduction rate of Cr(Ⅵ) was 20%. Also, the reduction rate of Cr(Ⅵ) was 60% in experiment of raw wastewater.

콘크리트 포장의 플라이애쉬 재활용 방안연구

정영화,최성용,윤경구,용석응,김태경 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

한국 대부분의 고속도로는 콘크리트로 포장되고 있으며, 플라이애쉬를 포장용 콘크리트에서 재활용하면 콘크리트의 성능을 향상시킴과 동시에 경제적 이익과 환경보호에 큰 기여를 할 것이다. 본 연구에서는 플라이애쉬를 포장 콘크리트에 재활용하고자, 플라이애쉬 치환율, 물-시멘트비, 굵은골재 최대치수를 주요실험 변수로 하여 이들이 플라이애쉬를 혼입한 포장용 콘크리트의 역학적 특성에 미치는 영향을 살피기 위해서 실험하여 통계처리 분석하였다. 이러한 분석결과를 바탕으로 포장 콘크리트의 적정배합을 제시하였으며 결과는 다음과 같다. 플라이애쉬를 혼입한 포장콘크리트의 휨강도에 영향을 미치는 인자는 플라이애쉬 치환율이 가장 큰 것으로 나타났으며, 다음으로 굵은골재 최대치수와 물-시멘트비 순으로 영향을 미친다. 또한, 플라이애쉬 치환율과 굵은골재 최대치수의 상관관계가 가장 큰 것을 알 수 있었다. 목표압축강도를 목표 휨강도의 6배로 선택하여 적정구간을 결정하였으나, 적정배합구간이 목표압축강도에 의해서 결정되었다. 이는 플라이애쉬의 작은 수화물이 공극을 효과적으로 채움으로써 휨강도의 증진에 크게 기여하기 때문으로 판단된다. 고속도로 포장에 적용할 수 있는 32mm의 굵은골재 최대치수와 45%의 물-시멘트비를 사용하는 목표 휨강도 45kg/㎠의 적정배합에서는 5.0%까지 플라이애쉬를 치환 가능하고, 50kg/㎠의 적정배합에서는 2.5%까지 치환 가능하다. 공항 포장에 적용할 수 있는 40mm의 굵은골재 최대치수와 37%의 물-시멘트비를 사용하는 목표 휨강도 45kg/㎠의 적정배합에서는 4.5%까지 플라이애쉬를 치환 가능하고, 50kg/㎠의 적정배합에서는 2.0%까지 치환 가능하다. The most of highway in Korea have been paved by concrete since last ten years. The recycling of fly ash in pavement concrete may result in economics, the improvement of concrete quality and the reservation of environment. This paper focused on the series of experiment and statistics analysis with experimental variables such as fly ash substitute ratio, water-cement ratio and maximum size of coarse aggregate in order to investigate the feasibility of recycling of fly ash in pavement concrete, to see the strength characteristics and t propose the optimum mix design based on previous results. The results of experiments and analysis were follows; The fly ash substitute ratio affected most seriously to the flexural strength of concrete among main variables, followed by maximum size of coarse aggregate and water-cement ratio. The interaction between fly ash substitute ratio and coarse aggregate size was the biggest. The optimum mix design was determined by target compressive, which was selected as 6 times of flexural strength. This indicated that the small hydrate of fly ash in concrete filled in effectively and resulted in the enhancement of flexural strength. the optimum mix design for highway pavement concrete with 32mm of maximum size of coarse aggregate and 45% of W/C can incorporate up to 5.0% and 2.5% of fly-ash at 45 kg/cm² and 50 kg/cm² of target flexural strength, respectively. The optimum mix design for airport pavement concrete with 40mm of maximum size of coarse aggregate and 37% of W/C can incorporate up to 4.5% and 2.0% of fly ash at 45 kg/cm² and 50 kg/cm² of target flexural strength, respectively.

한국인에서 미맹출 견치와 소구치의 근원심 폭경 예측을 위한 최적의 치아조합

김소화,김성오,최형준,최병재,이제호 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.3

peat moss를 이용한 폐수중의 중금속 제거

이경화,김정섭,유현철,최성우,윤철종,우성훈,박승조 동아대학교 환경문제연구소 2001 硏究報告 Vol.24 No.1

Adsorption equilibrium of heavy metals ion on the peat moss was confirmed Frundlich isotherm Removal efficiency of heavy metals ion was increased from pH 2 to 10 and heavy metal removal efficiency was increased in the sequence of Cu(Ⅱ) > Pb(Ⅱ) > Cd(Ⅱ) > Mn(Ⅱ) on the PM(Peat Moss). The PM is likely to be more effective adsorption than the PAC to removal of metal ions in the solution, since PM's weakly acidic functional groups which is not founded on the PAC, in addition to its high surface area and porosity. But, the PM is not separated from the solution water by sedimentation process. So, a liquid and solid seperation between the PM and the solution water could be considered for the PM's field application. But peat moss was low cost adsorbent. Thus author propose to adopt PM as a adsorbent for heavy metal removal.

인체 혈장에서 염산시프로플록사신(시프로플록사신으로서 250㎎) 정량을 위한 HPLC 분석법의 유효성검토

하용화,조성희,천성국,서성훈,류재환,최영욱,이경태 한국약제학회 2004 Journal of Pharmaceutical Investigation Vol.34 No.4

A simple HPLC method with ultraviolet detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation with trichloroacetic acid, chromatographic separation of ciprofloxacin in plasma was achieved at 50℃ with a C_18 column and methanol-phosphate mixture (pH 2.5), as mobile phase. Quantitative determination was performed by ultraviolet detection at 278 nm. The method was specific and validated with a limit of quantification of 100 ng/ml. The infra- and inter-day coefficients of variation were between 1.67% and 10.55% and accuracy between 92.01% and 106.09%. The method has been successfully applied in a bioavailability study of 250 ㎎ ciprofloxacin hydrochloride tablet.

FPGA를 이용한 문자인식 모듈의 구현에 관한 연구

박선화,이규원,최명아,엄성용 서울여자대학교 자연과학연구소 1999 자연과학연구논문집 Vol.11 No.-

Generally, character recognition needs complicated algorithms and transaction processes. Existing systems require high computing power and expensive devices, because they consist of softwares only. So they had no practical use. This paper proposes a solution for this problem, where image processing and character recognition processes are implemented into hardware using FPGA's. This paper focuses on the following points : (1) it attempts to extend usage of VHDL by embodiment of the complicated processes of character recognition field. (2) it provides an effective solution which combines practicality and economical efficiency. Test on the implemented hardware shows us that it works correctly as described in VHDL. We believe this work can be extended easily for other areas such as finger printing recognition.

플라이애쉬를 혼입한 콘크리트포장의 배합특성에 관한 실험적 연구

이주형,최성용,윤경구,정영화 江原大學校 産業技術硏究所 1997 産業技術硏究 Vol.17 No.-

As the weight of trucks increases, the need for concrete pavement also increases. Therefore, the addition of fly-ash may improve the properties of pavement concrete as well as recycle fly-ash. A full factorial experiment was performed using the primary variables, such as water-cement ratio, fly-ash substitution ratio, and maximum size of coarse aggregate, as a preliminary study for optimum mixture design for pavement concrete. The results of preliminary study indicates that the addition of fly-ash is the most important factor determining concrete strength, followed by the maximum size of coarse aggregate and water-cement ratio. It, also, shows the relative importance of fly-ash substitution ratio, compared to the water-cement ratio, and the interaction effects between the primary variables. Optimum mixture designs for pavement concrete incorporating fly-ash, that satisfied the target responses, were proposed in terms of fly-ash substitution ratio, water cement ratio and maximum size of coarse aggregate.

부신피질 자극호르몬 단독결핍 1례

박경식,이승현,최석영,박태규,이동화,이찬우,정성복,이인규 啓明大學校 醫科大學 1997 계명의대학술지 Vol.16 No.3

부신피질 자극호르몬 단독결핍은 국내에서 7례만이 보고된 희귀 질환이며 병인 및 경과 등 아직 불분명한 측면이 많다. 이는 질환지체의 희귀성도 있지만 치료후 자연경과에 대한 장기적인 추적검사가 이루어진 경우가 드물기 때문이기도 하다. 저자들은 비특이적인 전신증상을 주소로 내원한 폐경기후의 56세 여자 환자에서 자가면역질환의 증거없이 고프로릭틴혈증을 보인 부신피질 자극호르몬 단독결핍 1례를 경험하고 1년간의 부신피질호르몬 대치요법후 추적검사를 실시하였기에 문헌 고찰과 함께 보고하는 바이다. Isolated ACTH deficiency is a rare disorder which shows secondary adrenal insufficiency with normal states of other pituitary hormones. A 56-year-old postmenopausal woman complaining general weakness and intermittent mental confusion presented negligible serum cortisol and ACTH level with hyperprolactinemia and mild hyponatremia. Rapid ACTH stimulation test did not show significant increase of serum cortisol level. Combined pituitary stimulation test showed negligible response of cortisol and ACTH, and slightly decreased response of prolactin and gonadotropin. But the responses of TSH and GH were normal. There was no evidence of organic pituitary of hypothalamic lesion in brain MRI and antithyroid autoantibody was not detected in serum. After receiving 12 months of glucocorticoid replacement therapy, she skipped the medicine for 3 weeks and we performed follow-up endocrinologic tests. Serum ACTH and cortisol level was also negligible and prolonged ACTH simulation test showed normal response of serum cortisol. CRF stimulation test showed no response of serum ACTH. Basal prolactin level was decreased to near normal and combined pituitary stimulation test showed normal response of prolactin with slightly blunted response of TSH and GH. We concluded that the case was nonautoimmune origined isolated ACTH deficiency which was accompanied by hyperprolactinemia and resultant deficiency of gonadotropin, so we report this case with review of literatures.

제7차 교육과정에 따른 산ㆍ염기 단원의 STS과학 교육에 적합한 CBL 실험 프로그램의 개발

이광필,김동화,최성호,류재정,이무상 慶北大學校 師範大學 科學敎育硏究所 2001 科學敎育硏究誌 Vol.25 No.-

This study developed the 'advanced-supplementary' course experimental program with CBL(Calculator-Based Laboratory) system in conformity with the reform of the 7th science curriculum and applied the CBL experimental program to 'acid-base' chapter of middle-high school. The results of this study shows that a practical use of CBL system as powerful instrument can be applied to experiment program of 'acid-base' chapter in order to causes learner's motivation and enlarge a sphere of inquiry-activity in science.