콘크리트-폴리머 복합재료 개발(Ⅱ) : Physical Properties of Polymer(Resin) Concrete 폴리머(레진) 콘크리트의 물성

황의환,길덕수,황택성 공주대학교 자원재활용 신소재 연구센터 1999 1차년도 센터 성과집 Vol.1999 No.-

고기능성 건설재료로 활용하기 위하여 불포화폴리에스테르수지를 사용한 폴리머 콘크리트의 물성에 대하여 조사하였다. 탄산칼슘(충전제)의 첨가량(5~20 wt %)과 세골재의 첨가량(10~50 wt %)에 따라 다양한 공시체를 제작하여 압축 및 휨강도, 흡수시험, 내열수성시험, 내산성시험, 세공분포측정 및 SEM에 의한 미세조직 관찰등을 실시하였다. 그 결과 폴리머 콘크리트의 압축강도와 휨강도는 시멘트 콘크리트보다 4배 정도 향상되었고 흡수율은 1/100로 가소되었으며, 내산성시험에 의한 중량감소율은 1/27로 현저히 감소되었다. 내열수성시험후에 측정한 폴리머 콘크리트의 압축 및 휨강도는 모두 내열수성시험전에 측정한 강도에 비하여 67%, 47%로 각각 감소되었으며 폴리머결합체의 분해에 의하여 세공율은 크게 증가되었다. The phsical properties of polymer concrete were investigated for development of high performance construction materials. Various specimens of polymer concrete were prepared using unsaturated polyester resin as the ploymer binder with the various dosge of clcium carbonate as microfiller (5~20 wt %) and fine aggregate(10-50%). For the evaluation of the physical properties of polymer concretes, tests such as compressive strength, flexural stength, water absorption test, hot water immersion test, acid resistance test and pore size distribution analysis were conducted. As a result, it is concouded that compressive and flexural strengths of ployemr concretes increased up to 4times than those of conventional cement concrete. Whereas the compressive and flexural strengths of polymer concretes tested after hot water immersion, compared volume and porosity(%) of polymer concretes were remarkably increased due to decomposition of polymer binder. And also, it is showed that water absorption(%) and weight loss(%) of polymer concrete specimens by acid immersion, compared with those of ordinary portland cement cocrete decreased about 1/100, 1/27, respectively.

용접공들의 망간 폭로와 건강장해에 관한 연구

문덕환,강동묵,손병철 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : In order to evaluate the degree of manganese exposure and its health hazards effect on welders in manufacturing industry. Methods : The author measured airborne, blood and urine concentrations of manganese and blood chemistry, and also observed clinical symptoms and signs on 60 welders for case and 60 non-welders for control working in manufacturing industry by age maching method. Results : The geometric means of blood and urine concentrations of manganese were 1.13±1.38 ㎍/㎗ and 2.52±1.37㎍/ℓ for Welders group, 1.09±1.68 ㎍/㎗ and 1.86±1.34 ㎍/ℓ for Non-welders group. Airborne concentration of manganese was 0.15±1.66㎎/㎥ for exposured group, and the urinary mean concentration of manganese was statistically significant difference between exposured and non-welders group (P<0.05). Clinical signs in welders group were palmomentle reflex(23.3%), tremor(20.0%) and grabellar sign(5.0%). Symptoms in welders group were fatigue(66.7%), amnesia(66,7%), excessive sweating(51.7%), nervousness(51.7%), general weakness(48.3%) and arthralgia(46.7%) and so on, and there was statistically significant difference compared to non-welders group(P<0.05). Manganese effects on blood chemistry were not observed. There were statistically significant correlation between manganese concent- ration in blood and urine(r=0.269), airborne and urine(r=0.601) and airborne and blood(r=0.268). Conclusion : The author suggest that further studies are followed to evaluate the health status of welders whose blood and urine manganese concentrations were below normal reference level, and to establish the questionnaire and the diagnostic tools for early detecting the chronic manganese poisioning on welders.

유기용제 폭로가 여성 근로자들의 월경에 미치는 영향

김대환,이채관,김휘동,강동묵,문덕환,김정호,손병철,이창희,이채언 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.1

유기용제는 산업장에서 널리 사용되고 있다. 특히 여성근로자들의 폭로기회가 증가하고 있으며 이로 인한 자연유산, 수태능력 감소, 월경이상 등이 보고되고 있다. 따라서 유기용제 폭로가 여성근로자들의 월경에 미치는 영향을 보기 위해 설문조사와 월경주기별 여성생식 호르몬(progesterone, estrogen) 분석을 하였다. 그 결과 폭로군에서 progeterone의 억제효과가 유기용제에 폭로되는 여성근로자들의 다양한 월경이상을 초래할 가능성이 있는 것으로 생각된다. ■ Objectives This study was conducted to evaluate the effects of menstrual function in female workers exposed to organic solvents. ■ Methods Rates of menstrual disorders were studied in 87 female workers with exposure to organic solvents(Cn/Hn-value 0.713) in a factory manufacturing shoes and compared with 83 general female workers who had no exposure to organic solvents, Detailed menstrual and reproductive histories were obtained by personal interview using structured questionnaire, and plasma concentrations of progesterone and estrogen were assayed by radioimmunoassay(RIA). ■ Results The rates for menstrual irregularity, menstrual duration, blood clot in menstrual flow and dysmenorrhea were not significantly different in both groups. Number of using menstrual pad was significantly higher and the plasma level of progesterone during 6-11th day of menstrual cycle was significantly lower in the exposed group compared with non-exposed group(P<0.05). ■ Conclusions It seemed to be suppression effect of organic solvents on the reproductive hormones(progesterone and estrogen) in female workers. But there was no evidence that menstrual disorder was likely to result from exposure to organic solvents, because other behavioral, psychological and work related factors may also affect menstrual function.

X-Band 용 마이크로스트립 안테나 설계에 관한 연구

김환용,김태형,백덕수 圓光大學校 1992 論文集 Vol.26 No.2

마이크로스트립 안테나는 소형, 경량, 저가격, 평면구성의 장점을 가지므로 여러분야에 응용되고있다. 본 논문에서는 X-BAND용 마이크로스트립 안테나를 해석하고 설계하기위하여 이론적 해석이 용이한 사각형의 마이크로스트립 패치 안테나를 제작하여 전압정재파비(VSWR)와 복사패턴을 측정하여 좋은 결과를 보였다. Microstrip antenna is applied to various fields for his forte of compact-size, light-weight, low-cost and planar configuration. In this paper, rectangular microstrip patch antenna which give easy theoretical analysis is verified by the method of slot-transmission line modeling for the analysis and design of X-Band microstrip antenna. After that, microstrip patch antenna is fabricated and attained good measure results for VSWR and radiation pattern.

폐FRP 미분말을 재활용한 PAE 폴리머 모르타르의 물리적 특성

황의환,길덕수,노재성,이병기 공주대학교 자원재활용 신소재 연구센터 2002 센터사업 성과집 Vol.- No.1

In order to recycle the FRP wastes from SMC bathtubes, polymer-modified mortars containing a fine powder of fiber-rainforced plastics(FRP) as a part of the sand were prepared with various FRP replacements for sand and polymer cement rations. The polymer modifier used was polyacrylic ester(PAE) emulsion. The FRP waste fine powder was obtained by pulverizing FRP wastes. The water-cement ratio, compressive and flexural strength, water absorption and hot water immersion of the mortar were tested and the results compared to those of ordinary cement mortal and polymer-cement mortal. As the results, compressive and flexural strengths of ordinary portland cement mortars containing FRP wastes fine powder were remarkably decreased with an increase of a content of FRP wastes fine powder. But those strengths of ordinary portland cement mortars were greatly improved by adding PAE emulsion. When the replacement ratios of FRP wastes fine powder and adding rations of PAE emulsion were 5, 10, 20wt% and fine powder were showed as much those strengths of ordinary portland cement mortar. Otherwise heat curing of PAE-modified mortar containing FRP wastes fine powder accelerated the improvement of early compressive and flexural strengths. But the compressive and flexural strengths of PAE-modified mortar containing FRP wastes fine powder were remarkably decreased after hot water immersion test.

악성종양에서 혈청 Intercellular Adhesion Molecule-1의 혈청

조덕연,김현수,박상준,김종숙,최지영,윤환중,김삼용 충남대학교 의과대학 지역사회의학연구소 1995 충남의대잡지 Vol.22 No.1

Intercellular adhesion molecule-1 (ICAM-1) is a glycoprotein serving as ligands for leukocyte intergrin receptors, i.e. LFA-1, MAC-l. It has been suggested that the expression of ICAM-1 and the levels of circulating ICAM-1 were increased in several malignancies. We measured serum ICAM-1 by ELISA in patients with stomach cancer (n=25), acute lymphoblastic leukemia (n=7), non-Hodgkin's lymphoma (n=14), and metastasis of unknown origin (n=5). Serum levels of circulating ICAM-1 in all malignancies were significantly higer than in normal controls. And serum level of ICAM-1 in stomach cancer ptients having metastatic disease was higher than in patients with localized disease (p=0.027). These results suggest that elevated serum ICAM-1 is a rather common feature for malignancies, not unique for certain types of cancer such as malignant melanoma. It remains to be clalified whether marked increase of serum ICAM-1 in metastatic stomach cancers simply reflect tumor burden or this molecule plays a role in progression in stomach cancer.

급성골수백혈병에 대한 관해유도화학요법 후의 Granulocyte Colony-stimulating Factor의 효과

윤환중,최지영,전의건,길준영,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.2

Granulocyte colony-stimulating factor(G-CSF) have been shown to hasten the recovery of neutropenia following anti-cancer chemotherapy. There are controversial opinions on the use of G-CSF in acute myelogenous leukemia(AML) because clonogenic studies have shown that G-CSF stimulates leukemic colonies as well as granulocyte colonies. In this study, we evaluated the effectiveness and safety of recombinant human G-CSF after induction chemotherapy with DAV regimen(Ara-C 100mg/㎡ day 1-8, Doxorubicin 45mg/㎡ day 3-5, VP-16 100mg/㎡ day 6-8) in 9 patients with AML. G-CSF therapy(200 ㎍/㎡/day) was begun 2 days after the end of chemotherapy and continued for 10 days. 17 AML patients who recieved the same chemotherapy before the onset of this study were used as historical control. G-CSF shortened the duration of granulocytopenia (less than 500/㎣) significantly (13 vs 23 days, p<0.001), but it had no effect on platelet recovery. Although the incidence of febrile episodes was almost the same, the duration of febrile episodes was shorter in the group treated with G-CSF( 5 vs 12 days, p=0.03). There was no evidence that G-CSF accelerated the regrowth of leukemic cells and the complete remission rates between the 2 groups were not different. These results show that G-CSF accelerates the recovery of granulocytopenia and shortens the febrile days after chemotherpy in patients with AML, without affecting the regrowth of leukemic cells.

도금사업장의 작업환경의 유해인자 노출수준에 관한 연구

문덕환,도수영,이채관,황용식,선병관,손병철,김대환,이창희,김휘동,이채언 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

Objective : For the purpose of preparing the fundamental data and assessing the status of exposure level of chemical substances and physical agents. Methods and Material : Such as noise, two types of dust, four types of metals, seventeen types of organic solvents, and four types of other materials classified by specific chemical substances in 21 metal product plating factories classified by 28 processes. The author determined exposure level on those hazardous materials from Jan. to Dec. 2001. Results : The results were as follows: 1. The exposure level for noise was exceeded to Threshold Limit Value(TLV) in the process of 6 cases of Machining, 5 and 4 cases of pre and post-buffing, and 6 cases of waterdrop-removing, the mean noise level of all of processes was not exceeded to compliance level. 2. The exposure level for dust was not exceeded to TLV at all. 3. The exposure level for Chromium(Cr) was exceeded to TLV in Chromium plating process, metal exposure level including Zinc(Zn), Manganese(Mn), and Lead(Pb) was not exceeded to TLV. 4. The exposure level of toluene in case of organic solvents was exceeded to TLV in 1 case of finishing/cleaning, coating/developing process, respectively. 5. The exposure level of four types of other materials classified by specific chemical substances were not exceeded to TLV. 6. The exposure level for dust and metal including Zn, Mn, and Pb was decreased in comparison with two results of air monitoring performed. There was no difference of the exposure level for Cr, noise, and four types of other materials classified by specific chemical substances, and the exposure level for organic solvents was slightly increased. 7. The exposure level for noise in factories employing more than 21 workers was higher than that for noise in foadtories employing less than 20 workers. The more workers, the lower exposure level in metal including Zn, Mn. The exposure level for Cr was increasing in factories employing more than 51 workers, and the more workers the lower exposure level in organic solvents. Conclusion : According to above results, this study suggests positive work environment managements in processes exceeding exposure limit value as well as continuously consecutive work environment management in processes not exceeding exposure limit value and revealing no chronological difference of exposure level should be needed.

영국 쉐필드(Sheffield) 시 도심재생계획의 특징에 관한 연구

김영환,백기영,오덕성 대한건축학회 2003 대한건축학회논문집 Vol.19 No.9

This paper aims to search the characteristics of urban regeneration in England and find the suggestion for the urban regeneration in Korea. For this purpose, we reviewed the urban regeneration techniques in physical/spatial aspect and established analysis framework for case study, which is consisted of historic/cultural environment, pedestrian street, mixed-use, urban housing, retail facilities. Site for case study was chosen Sheffield City Center district, because she has various experiences concerning urban decline and urban regeneration in modern history. As a result of this study, we can draw some characteristics of city center regeneration in Sheffield such as consistent urban policy & organic linkage between related plans, clear strategic vision & masterplan-led approach, well-developed project oriented urban regeneration plan, collaborative partnership between public/private sector, reflecting resource in place to deliver based on baseline study, and citizen participation and community-based approach etc.

제조업 산업장의 유기용제 노출에 관한 연구

문덕환,김정하,김필자,박명희,황용식,이채관,이창희 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.3

Objective : For the purpose of preparing the fundamental data and health promotion and control program on organic solvents in air of manufacturing industry. Methods : The author surveyed number of organic solvent components which was used in working site and also determined the organic solvents concentration in air of 927 manufacturing industries and 1,267 working process with gas chromatography(NIOSH manual) for five years from 1995 to 1999. Results : Mean numbers of solvents components by type of industry, working process was number of 12. There were exceeded to TLV of 1,2-dichloroethane in textile manufacturing industry N,N-dimethyl furan in tanning and dressing of leather ; luggage, handbags, saddlery, harness and footwear manufacturing industry and chemical and chemical product manufacturing industry by type of industry. There were exceeded to TLV of 1,2-dichloroethane in handwriting and drawing process, cellosolove in adhesive spreading process, N,N-dimethly furan in production of solvent process and adhesion process by working process. Total exceeded rate to threshold limit values of organic solvents mixture were 12.9% for EI(Exposure index) and 10.0% for Em(Estimation of mixture) by type of industry, 11.3% for EI and 8.2% for Em by type of working process. The highest exceed rate was 36.7% for EI in tanning and dressing of leather ; luggage handbags, saddlery, harness and footwear manufacturing industry and 29.0% for Em in textile manufacturing industry. the highest exceeded rate was 23.1% for EI and 12.5% for Em in adhesive spreading process by working process. Mean values of total subjects by type of industry and type of working process were 0.7±1.8 for EI and 0.7±1.7 for Em respectively. Conclusions : As above results, the author suggest that it makes the environmental control program on 1.2-dichloro-ethane, N,N-dimethyl furan, cellosolve by kind of organic solvent and on textile manufacturing industry, tanning and dressing of leather ; luggage, handbags, saddlery harness and footwear manufacturing industry by type of industry, and on handwriting, drawing process and adhesive spreading process and adhesion process by type of working process.