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.

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.

전형적인 DISIDA scan 소견의 Rotor 증후군 1예

황의태,염동한,권지혜,임종주,최창수,김태현,김학철 圓光大學校 醫科學硏究所 2008 圓光醫科學 Vol.23 No.2

만성의 비용혈성 직접형 고빌리루빈혈증은 Rotor 증후군과 Dubin-Johnson 증후군의 특징적인 소견으로, Rotor 증후군은 드문 양성 유전성 질환이며, Dubin-Johnson 증후군과 감별을 필요로 한다. 본 저자들은 황달을 주소로 내원한 26세 남자 환자에서 고빌리루빈혈증에 대한 검사를 시행하여 담도폐쇄 소견없이 간담도 스캔상 전형적인 Rotor 증후군의 소견 즉, 강한 심장 배후방사능이 지속되면서, 간담도계의 조영은 지연 촬영에서도 관찰되지 않으며 신장으로의 배설이 계속 관찰되는 특징적인 소견과 정상 간조직 검사 결과로 Rotor 증후군으로 진단한 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. Chronic nonhemolytic conjugated hyperbilirubinemia characterizes both Rotor and Dubin-Johnson syndromes. Rotor syndrome is a rare, benign familial disorder and needs to be differentiated from Dubin-Johnson syndrome. Cholescintigraphy is a simple and informative procedure for the diagnosis, which can differentiate Rotor syndrome from Dubin-Johnson syndrome. A 26-year-old man was admitted due to asymptomatic persistent jaundice. Physical examination revealed icteric sclera without hepatosplenomegaly. Laboratory findings showed increased serum bilirubin with direct bilirubinemia. Markedly decreased hepatic uptake and poor visualization of the gallbladder and biliary tract were shown in ^(99m)Tc-DISIDA scan. Histology of the liver showed no diagnostic abnormality without pigmentation. But, we report a case of Rotor syndrome that showed characteristic cholescintigraphic findings with normal urinary total coproporphyrin excretion.

두부회전에 따른 측모두부방사선 계측치의 변화

김광수,황미선,최의환,김광원,윤영주 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.1

본 연구는 측모두부방사선사진 촬영시 발생될 수 있는 두부회전이 측정된 선, 각계측치들에 어느 정도의 투사오차를 야기시키는지 알아보기 위해 조선대학교 의과대학 해부학교실에 소장중인 건조두개골 중 비교적 상태가 양호하고 특별한 비대칭이 없는 영구치열기의 건조두개골 17개를 표본으로 선택하여 시행하였다. 각각의 건조두개골을 수직축(Z축)을 중심으로 기준위치(0˚)에 대해 1˚ 간격으로 ±15˚ 까지 실험적으로 회전시켜 총 527장의 측모두부방사선사진을 촬영하였다. 이를 근거로 기준위치(0˚)에서의 계측치와 각 회전각에서의 계측치들 사이에 paired t-test를 시행하여 측모두부방사선사진 계측치 간의 차이를 규명하였으며, 이를 통해 투사오차의 관점에서 교정학적으로 유용한 측모두부방사선 계측항목을 구한 결과 다음과 같은 결론을 얻었다. 1.각계측항목이 선계측항목에 비해 투사오차가 작았다. 2.각계측항목은 정중시상면에 위치한 기준점들을 많이 포함할수록 투사오차가 작았다. 3.수평선계측항목의 길이는 필름방향으로 회전됨에 따라 점진적으로 감소되었으나, 초점 방향으로 회전됨에 따라서는 증가되다가 감소되었으며 상대적으로 그 변화양이 작았다. 4.두부회전에 따른 투사오차는 수직선계측항목에 비해 수평선계측항목에서 컸다. 5.수직선계측항목은 회전축으로부터 거리가 증가함에 따라 투사오차가 증가하였다. 이상을 종합해 볼 때 두부회전에 따른 측모두부방사선사진 계측치의 투사오차를 최소로 하기 위해서는 선계측항목보다는 각계측항목을 사용하는 것이 유용할 것으로 사료된다. This study was performed to find out the effect of projection errors on cephalometric linear and angular measurements according to head rotation during taking lateral cephalometric radiographs. Seventeen skulls with permanent dentition and no gross asymmetry were obtained from the Department of Anatomy, Medical School, Chosun University. Total 527 x-ray films were taken with 1˚ interval from the reference position(0˚) to ±15˚ around the vertical axis (Z axis) which is perpendicular to the midpoint of the line connecting the center of two ear rods in submento-vertex direction. Statistical analysis was performed by faired t-test if there were statistically significant differences between the mean of the reference position(0") and that of each rotation angle. The following results were obtained. 1.The projection errors of angular measurements were smaller than those of linear measurements. 2.The projection errors of angular measurements including midline landmarks were smaller than those including bilateral landmarks. 3.The horizontal linear measurements were gradually decreased when the skull was rotated toward the film, but slightly increased and then decreased when the skull was rotated toward the focal spot. However, the changes were smaller in focal direction. 4.The projection errors of horizontal linear measurements were larger than those of vertical linear measurements. 5.The projection errors of vertical linear measurements were increased with increased distance from the rotation axis to vertical measurements. It is concluded that the use of angular measeurements rather than linear measurements is recommended to minimize the projection errors.

하악 제3대구치와 하악관과의 위치관계에 대한 파노라마 방사선사진과 cone beam형 전산화단층영상의 비교

최형수,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.3

Purpose : To assess the diagnostic accuracy and value in an imaging technique field through the comparison of cone beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars. Materials and Methods : Participants consisted of 100 patients offered the images through cone beam computed tomography and panoramic radiography. PSR-9000 Dental CT system (Asahi Roentgen Ind. Co., Ltd, Japan) was used as the unit of cone beam computed tomography. CE-II (Asahi Roentgen Ind. Co., Ltd, Japan) and Pro Max (Planmeca Oy, Finland) were used as the unit of panoramic radiography. The images obtained through panoramic radiography were classified into 3 types according to the distance between mandibular canal and root of mandibular third molar. And they were classified into 4 types according to the proximity of radiographic feature. The images obtained through cone beam computed tomography based on the classification above were classified into 4 types according to the location between the mandibular canal and the root and were analyzed. And they were classified into buccal, inferior, lingual, and between roots, according to the location between mandibular canal and root. The data were statistically analyzed and estimated by χ²-test. Results : 1. There was no statistical significance according to 3 types (type l, type ll, type lll) through CBCT. 2. The results of 4 types (type A, type B, type C, type D) through CBCT were as high prevalence of CBCT 1 in type A, CBCT 2 in type B, CBCT 3 in type C, and CBCT1 in type D and those of which showed statistical significance (P value=0.03). 3. The results according to location between mandibular canal and root through CBCT recorded each 49, 25, 17, 9 as buccal, inferior, lingual, between roots. Conclusion : When estimating the mandibular canal and the roots through the panoramic radiography, it could be difficult to drive the views of which this estimation was considerable. Thus it is required to have an accurate diagnostic approaching through CBCT that could estimate the location between mandibular canal and roots.

급성 포름알데히드 가스 흡입에 의한 흰쥐 후각상피의 형태학적 변화

백선용,전재기,문용석,황승영,노환중,고의경,왕수건 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.3

외부광궤환에 의한 레이저 다이오드의 출력특성

이세영,오차환,김필수,황의중 漢陽大學校 自然科學硏究所 1997 自然科學論文集 Vol.16 No.-

외부 광궤환 반도체 레이저의 출력 특성을 비율방정식의 수치해를 이용하여 분석하였다. 출력의 세기와 위상과 전자밀도를 시간에 대한 함수로 알아보았다. 또한 bifurcation diagram과 phase diagram을 통하여 궤환비율 k에 따른 레이저의 동작 특성을 조사하였다. 궤환광이 없을때는 이완발진이 감쇄한 후 안정한 출력특성이 나타나지만 되먹임 비율이 증가하면서 안정한 해의 갯수가 증가하다가 ??????이상의 매우 강한 광궤환에서는 출력특성이 극도로 불규칙해지고 무수히 많은 해를 갖는 혼돈현상이 나타남을 알 수 있었다. The output characteristics of a laser diode with external optical feedback were analyzed by numerical solutions of rate equations. The output power, phase and carrier density were plotted as a function of time. Dynamics of external cavity laser were investigated by the bifurcation diagram and the phase diagram with respect to the feedback rate k. If there was no feedback, relaxation oscillation reduced and laser showed stable output. For increasing feed back level, the number of stable state was increased. In very strong feedback rate above ??????, laser output showed extremely unstable and chaotic behavior.

콘크리트 - 폴리머 복합재료 개발 (2) - 폴리머 ( 레진 ) 콘크리트의 물성 -

황의환(Eui Hwan Hwang),황택성(Taek Sung Hwang),길덕수(Deog Soo Kil) 한국공업화학회 1999 공업화학 Vol.10 No.7

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호지킨병 초기에 주증상으로 발현된 거대세포바이러스 유발 위궤양

황의태 ( Eui Tae Hwang ),이준영 ( Jun Young Lee ),정진수 ( Jin Soo Chung ),이재훈 ( Jae Hoon Lee ),최창수 ( Chang Soo Choi ),김태현 ( Tae Hyeon Kim ),최석채 ( Suck Chei Choi ) 대한소화기학회 2009 대한소화기학회지 Vol.54 No.2

Cytomegalovirus (CMV) is an important cause of opportunistic infection in immunocompromised patients. CMV infection occurs as a result of the cell-mediated immunity change in lymphoma patients. Although CMV can cause ulceration anywhere in the gastrointestinal (GI) tract in immunocompromised patients, only a few case reports about CMV GI infection in malignant lymphoma have been documented in literature. Furthermore, it was rare that CMV gastric ulcer with massive bleeding presented as an initial manifestation in a patient who has been not diagnosed lymphoma. We report a case of CMV induced gastric ulcer as an initial manifestation in patient with Hodgkin`s disease. (Korean J Gastroenterol 2009;54:117-122)

Establishment of transgenic fibroblasts for producing recombinant human interferon-α and erythropoietin in bovine milk.

Jung, Eui-Man,An, Beum-Soo,Kim, Yu-Kyung,Hwang, Inho,Lee, Jong-Yun,Shin, Tae-Young,Hyun, Sang-Hwan,Hwang, Woo-Suk,Jeung, Eui-Bae D. A. Spandidos 2013 MOLECULAR MEDICINE REPORTS Vol.7 No.2

<P>Human interferon α (IFN-α) and erythropoietin (EPO) have been used for a variety of purposes in clinical medicine. Human IFN-α has been used to treat several types of viral infection and cancer, as well as renal anemia, via stimulation of erythrocyte formation in the bone marrow. Transgenic cattle are excellent candidates for pharmaceutical production for humans due to their ability to produce recombinant proteins in milk. The purpose of the present study was to generate bovine transgenic fibroblasts capable of producing recombinant human IFN-α and EPO proteins in transgenic cattle milk. First, we analyzed the promoter activities of various bovine milk protein genes in HC11 mouse mammary epithelial cells. The bovine milk protein gene promoters were cloned into the Luc gene in a promoter-less pGL3-Basic vector. Presence of the αS1-casein promoter (-175 to +796 nt) resulted in an up to 16-fold increase in luciferase activity compared with that of the promoter-less construct. In addition, the human IFN-α and EPO genes were identified as significantly overexpressed in HC11 cells compared with the promoter-less construct. Together, the present results demonstrate that the construct with the αS1-casein promoter may induce secretion of recombinant human IFN-α and EPO into bovine milk. Furthermore, we generated transgenic fibroblasts expressing human IFN-α and EPO cDNA controlled by the αS1-casein promoter and two screening markers, enhanced green fluorescent protein and neomycin resistance. These transgenic fibroblasts may be a source of somatic cells for generating transgenic cattle that produce recombinant human IFN-α and EPO proteins during lactation.</P>