아토마이징 제강 환원슬래그를 사용한 폴리머 콘크리트 복합재료의 특성 (I) (PMMA 수축저감재를 사용)

황의환,김진만,Hwang, Eui Hwan,Kim, Jin Man 한국공업화학회 2014 공업화학 Vol.25 No.2

In order to use the spherical atomizing reduction steel slag (ladle furnace slag, LFS) instead of the fine aggregate of polymer concrete composites, various specimens were prepared with various replacement ratios of atomizing reduction steel slag and the addition ratios of polymer binder. Physical properties of these specimens were investigated through the absorption test, the compressive strength test, the flexural strength test, the hot water resistance test, the pore analysis and the micro-structure using scanning electron microscope. Results showed that the compressive strength and flexural strength of specimens with 7.5% of polymer binders increased with the increase of replacement ratios of atomizing reduction steel slag, but those of the specimens with 8.0% or more of polymer binders showed a maximum strength at a certain replacement ratio due to the material segregation causing the increase of fluidity. By hot water resistance tests, the compressive strength, flexural strength, average pore diameter, and bulk density decreased but the total pore volume and pore diameter increased. It was concluded that the amount of polymer binders could be reduced by maximum 23.8%, because the workability of the polymer concrete was remarkably improved by using the atomizing reduction steel slag instead of fine aggregate. However, since the use of atomizing reduction steel slag decreased the resistance of the polymer concrete to hot water, further studies are required. 구형의 아토마이징 제강 환원슬래그(래들로 슬래그)를 폴리머 콘크리트 복합재료의 잔골재 대신 사용하기 위하여 아토마이징 제강 환원슬래그의 대체율과 폴리머 결합재의 첨가율을 다양하게 변화시켜 공시체를 제작하였다. 공시체의제 물성을 조사하기 위하여 흡수시험, 압축 및 휨강도, 내열수성시험, 세공분포측정 및 SEM에 의한 미세조직 관찰을 실시하였다. 그 결과 폴리머 결합재 7.5% 첨가한 공시체는 제강 환원슬래그의 대체율이 증가됨에 따라 압축 및 휨강도가 증가되었으나 폴리머 결합재 8.0% 이상에서는 유동성의 증가로 인한 재료분리 현상으로 특정한 대체율에서 최대값을 나타내었다. 내열수성시험에 의하여 압축강도, 휨강도, 세공의 평균직경 및 밀도는 감소되었으나 총세공량과 공극률은 증가되었다. 아토마이징 제강 환원슬래그를 잔골재 대신 사용함으로써 유동성이 현저히 증가되어 폴리머 결합재의 사용량을 최대 23.5%까지 절감할 수 있는 것으로 나타났다. 그러나 아토마이징 제강 환원슬래그를 사용함으로써 내열수성이 감소되기 때문에 더 많은 연구가 요구된다.

2P-664 아토마이징 제강 산화슬래그를 잔골재로 대체한 폴리머 콘크리트의 강도특성

황의환,송민규,조원희,하금수,정은서,고정욱,김병규 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

Metastatic adenocarcinoma of the mandible

황의환,황지영,이상래 대한영상치의학회 2004 Imaging Science in Dentistry Vol.34 No.4

Metastases to the jawbones are found predominantly in the mandible and are rare in relation to the overall spectrum of oral malignancy. Analysis of the literature shows that the most frequent primary sites are the breast, lung, kidney, thyroid, and prostate. Adenocarcinoma of the mandible, whether primary or metastatic, are usually difficult to diagnose clinically. We report a case illustrating the clinical, radiographic, and histologic findings of a metastatic lung adenocarcinoma of the anterior mandible in a 58-year-old male. (Korean J Oral Maxillofac Radiol 2004; 34 : 219-23)

폐콘크리트 미분을 재활용한 폴리머 복합재료 개발

황의환 공주대학교 자원재활용 신소재 연구센터 2003 센터사업 성과집 Vol.- No.4

중.저준위 방사성 폐기물 처분용기용 보강 콘크리트의 특성

황의환,황선태,홍원표,조헌영 한국세라믹학회 1988 한국세라믹학회지 Vol.25 No.5

Concrete used for radwaste container should have excellent properties such as mechanical strength, water-tightness, durability, etc. In order to improve such properties of ordinary portland cement concrete, superplasticizer, steel fiber, and/or epoxy resin were added to ordinary portland cement concrete respectively. Various concrete specimens were prepared and the physical properties of each concrete specimen were tested. From the experimental results, the properties of steel fiber and epoxy resin reinforced concrete were proved to be better qualified than others for low-and intermediate-level radwaste container.

상악중절치부위에 발생된 정중과잉치의 X선학적 연구

김영일,이상래,황의환 大韓口腔顎顔面 放射線學會 1991 Imaging Science in Dentistry Vol.21 No.2

The clinical and radiographic features of 1,171 mesiodenses were studied with periapical radiograms and/or pantomograms in 942 persons visited the Department of Oral Radiology, School of Dentistry, Kyung Hee University during January 1980 to December 1989. The obrained results were as follows: 1. The incidence of mesiodens was higher in males (75.4%) than in females (24.6%). 2. In number of mesiodenses per individual, a single mesiodens was found to be 75.9%, 2-mesiodenses to be 23.8%, and 3-mesiodenses to be 0.2%. 3. In mesiodenses according to erupted and impacted status, the erupted mesiodens was found to be 16.5%, the impacted mesiodens in the interdental alveolar bone to be 66.6%, and in the region below root apex to be 16.9%. 4. In impacted mesiodenses according to direction of tooth crown, the inverted impaction was found to be 68.8%, the vertical impaction to be 15.1%, and the angulated impaction to be 16.1%. Among the impacted mesiodenses, a palatally located impaction was 87.5%, a middle 4.9%, and a labially 7.6%. 5. In mesiodenses according to shape of the tooth crown, a incisor-like type was found to be 1.6%, a canine-like type to be 6.8%, a conical type to be 79.2%, and a tuberculated type to be 12.4%. 6. In effect of mesiodens on adjacent tooth, non-specific influences were found to be 73.4%, crowing to be 0.3%, diastema to be 11.8%, rotation to be 5.7%, delayed eruption to be 3.8%, root resorption to be 2.6%, and dentigerous cyst to be 2.4%.

메틸메타크릴레이트를 수축저감재로 사용한 UP-폴리머 복합재료의 내약품성

황의환,이다혜,이태희 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

불포화폴리에스테르 수지의 희석제로는 메틸메타크릴레이트와 아크릴로니트릴을 사용하였고, 경화제로 methyl ethyl ketone peroxide, 가속제로 cobalt octoate를 사용하였다. 20종류의 공시체를 제작하여 4종류의 시약(황산, 초산, 수산화나트륨 및 염화칼슘) 수용액에 28일간 침적시켜 중량 변화율과 강도 감소율을 측정하였다. 측정결과, 내약품성은 이소-타입 불포화폴리에스테르 수지를 폴리머 결합재로 사용한 공시체가 올소-타입 불포화폴리에스테르 수지를 사용한 공시체보다 내약품성이 더 우수한 것으로 나타났다. 아크릴로니트릴을 20% 대체하여 제조한 공시체는 황산, 초산 및 염화칼슘 수용액 시험에서는 올소-타입 불포화 폴리에스테르 수지 공시체가 우수하였으나 이소-타입 불포화폴리에스테르 수지 공시체는 열등한 것으로 나타났다. 수산화나트륨 수용액시험에서는 올소-타입과 이소-타입 모두 열등한 것으로 나타났다. ** 본 연구는 2017년도 한국연구재단의 기초연구사업 지원을 받아 수행된 것임(과제번호: 2017R1D1A3B03030614).

방사선조사가 Porphyromonas gingivalis에 미치는 영향

이창환,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.1

Purpose : The aim of this study was to observe a direct effect of irradiation on the periodontopathic Porphyromonas gingivalis (P. gingivalis). Materials and Methods : P. gingivalis 2561 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Changes in viability and antibiotic sensitivity, morphology, transcription, and protein profile of the bacterium after irradiation were examined by pour plating method, disc diffusion method, transmission electron microscopy, RT-PCR, and immunoblot, respectively. Results : Viability of irradiated P. gingivalis drastically reduced as irradiation dose was increased. Irradiated P. gingivalis was found to have become more sensitive to antibiotics as radiation dose was increased. With observation under the transmission electron microscope, the number of morphologically abnormal cells was increased with increasing of irradiation dose. In RT-PCR, decrease in the expression of fimA and sod was observed in irradiated P. gingivalis. In immunoblot, change of profile in irradiated P. gingivalis was found in a number of proteins including 43-kDa fimbrillin. Conclusion : These results suggest that irradiation may affect the cell integrity of P. gingivalis, which is manifested by the change in cell morphology and antibiotic sensitivity, affecting viability of the bacterium.

LiAlH₄를 이용한 탈염화 반응에 의한 PCS-DMVS 세라믹 전구체의 합성과 열분해 특성에 관한 연구

손원근,신경섭,이존태,황택성,황의환 忠南大學校 産業技術硏究所 1998 산업기술연구논문집 Vol.13 No.2

The new ceramic precursors, Polycarbosilane(PSC)-dichloromethylvinylsilane(DMVS) were synthesized by hydrosilation reaction with Platinum catalyst and reduction with LiAlH₄. The structure and thermal degradation properities of new PCS-DMVS copolymers were characterized by using FT-IR, ¹H-, Si-NMR spectrometers and thermogravimetric analysis(TGA).

Primary intraosseous carcinoma of the mandible

황의환,최용석,이상래 대한영상치의학회 2005 Imaging Science in Dentistry Vol.35 No.4

A very uncommon tumor, primary intraosseous carcinoma (PIOC), is a carcinoma arising within the jaw. Thedefinite diagnosis of PIOC is often difficult as the lesion must be distinguished from alveolar carcinoma that may invade the bone from the overlying soft tissues or from the tumors that have metastasized to the jaw from a distant site. A case of PIOC arising in the mandible is presented. The clinical, radiologic, and histologic features are described. This rare lesion should be considered in any differential diagnosis of a jaw radiolucency.