폐수슬러지를 혼입한 콘크리트의 재료특성 및 강도특성

홍기호,하상훈,김정규,어석홍 國立 昌原大學校 產業技術硏究院 2004 産技硏論文集 Vol.18 No.-

The purpose of this study is to investigate the material characteristics and strength properties of concrete mixed with wastewater sludge, and to evaluate the leaching of environmentally harmful heavy metals from the wastewater sludge itself and from hardened concrete mixed with wastewater sludge. For this purpose, a reference mix with W/C ratio of 0.45 was used and the replacement proportion of wastewater sludge was varied with ratios of 0, 30, 50, 70 and 100% by volume of coarse aggregate in the reference mix. The variations of compressive and splitting tensile strength, workability and unit weight of concrete were considered. Test results showed that the strengths and unit weight decreased with increase in proportion of wastewater sludge replaced, but workability increased. Leaching test results showed that there would be no environmentally harmful problem from using wastewater as substitutes of coarse aggregates in concrete.

쓰레기 소각재를 잔골재로 혼합한 콘크리트의 기초적 물성연구

홍기호,하상훈,김정규,어석홍 國立 昌原大學校 產業技術硏究院 2004 産技硏論文集 Vol.18 No.-

The purpose of this study is to investigate the material characteristics and strength properties of concrete mixed with waste incinerated bottom ash(BA), and to evaluate the leaching of environmentally harmful heavy metals from the bottom ash itself and from hardened concrete mixed with bottom ash. For this purpose, two reference mixed with W/C ratio of 0.45 and 0.55 were used, and the replacement proportion of BA was varied with ratios of 0, 30, 50, 70 and 100% by volume of fine aggregate in the reference mixes. The variation of compressive and splitting tensile strength, workability and unit weight of concrete were considered. Test results showed that the strengths, workability and unit weight decreased with increase in proportion of BA replaced. Leaching test results showed that there would be no environmentally harmful problem from using BA as substitutes of fine aggregates in concrete.

한국인 선천성 난청에서 Connexin 26의 분자유전학적 분석

박홍준,박기현,송정환,정영훈,최호석 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.4

국내에서 분리된 Extended-Spectrum β-Lactamase 생성 Escherichia coli와 Klebsiella pneumoniae의 빈도 및 유형

홍성근,김선주,정성훈,장철훈,조성란,안지영,신종희,이혜수,송원근,어영,염종화,용동은,이경원,정윤섭 대한임상미샐물학회 2003 Annals of clinical microbiology Vol.6 No.2

휴대폰 케이스 가공업체에서 발생한 은피증 1예

탁기홍,윤석환,이미영,신동훈,정인성 대한산업의학회 2006 대한직업환경의학회지 Vol.18 No.4

배경: 은피증은 은의 피부 침착에 의해서 생기는 질환으로, 만성적인 노출에 의해 생기며, 치료법이 없는 영구적인 질병이다. 은의 흡입에 의한 은피증의 보고는 아주 드물며, 우리나라에는 현재까지 관련 보고가 없었다. 이에 휴대폰 도장제의 은 흡입에 의한 은피증을 보고하고자 한다. 증례: 30세 남자근로자로 5년 전부터 휴대폰 부품조립 및 도장업체에서 EMI부서와 가스켓부서에서 전자기파 차단제를 스프레이 도장하는 작업을 하였고, 3년 전부터 서서히 발생한 얼굴과 몸의 회색 및 회청색 피부색 변화를 주소로 내원하였다. 전자기파 차단제는 은, 구리, 용제들로 구성되어 있었다. 피부 조직 검사에서 에크린 한선 기저판(basal lamina)에 미세하고 둥근 흑갈색 과립들이 관찰되어 은피증의 소견을 보였으며, 작업중 노출된 은 흡입에 의한 직업성 은피증으로 진단하였다. 킬레이트 치료는 도움 되지 않으며, 노출 중단 및 자외선 차단 등의 보존적인 방법을 사용하고 있다. 고찰: 은피증은 은의 복용, 흡입, 접촉에 의해 발생한다. 본 증례에서는 은피증을 원인으로 작업시의 은 노출 이외의 은 노출을 발견할 수 없었다. 그러므로, 직업성 은피증으로 사료되며, 은의 첨가제에 의해 은피증이 발생 할 수 있음을 보여준다. 현재 전자기파 차단의 용도로 은과 은 화합물의 사용이 계속되고 있으므로, 이에 대한 대책이 필요하다고 본다. 적절한 치료법이 없기 때문에, 예 방이 가장 중요하며, 보호구 착용, 작업환경 개선, 산업 안전보건교육이 필요하다. Background: Skin contact with, and the breathing in of air containing silver compounds can occur in the workplace. Occupational exposure to silver and its compounds is mainly via airborne dust, metal fumes, and mists of solutions containing silver compounds. Argyria results from increased serum silver levels and the deposition of silver-containing particles in the dermis and mucous membranes. The author reports a patient with generalized argyria, who worked on the manufacture of cellular phone cases. Case report: The patient was a 30 year-old male, with extensive blue-gray discoloration of the whole body, especially sun-exposed area, of 3 years duration. He had been exposed to silver in the processing of EMI for the past 4 years and gaskets for 1 year. EMI is the process by which the internal electromagnetic wave in cellular phone cases are shielded, and gaskets play an important role in shielding the electric clashes between electronic circuits, as well as increasing the durability of cellular phone cases to impact. EMI had been processed manually but this was changed to automatic spraying by robots in 2003. On physical examination, the patient had diffuse blue-gray discoloration of the skin, which was most prominent in the sun-exposed areas of his face, neck and V of the chest. Histopathological examination of a punch biopsy specimen from the posterior neck revealed fine, minute, round, and brown-black granules deposited in the basement membrane zone surrounding the eccrine glands. The laboratory findings were positive for hepatitis B antigen, with a serum silver concentration of 150.3 ppb. From this evidence, he was diagnosed with argyria due to silver exposure. Discussion: The author reports a case of occupational systemic argyria due to inhalation exposure of silver compounds.

감염 조절용 차단막의 두께가 광중합기의 중합광에 미치는 영향

장훈상,이석련,홍성옥,류현욱,송창규,민경산 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.5

연구목적: 본 연구는 감염 조절용 차단막을 여러 겹으로 사용했을 때 광중합기의 광강도와 파장, light diffusion 등에 미치는 영향에 대해 조사하였다. 연구 재료 및 방법: 감염 조절용 차단막은 투명 랩 (크린랩)을 사용하였고 광중합기는 할로겐 광중합기 (Optilux 360)와 LED 광중합기 (Elipar FreeLight 2)를 사용하였다. 차단막을 1겹, 2겹, 4겹, 8겹으로 광중합기의 광섬유말단을 감싸고 휴대용 광강도 측정기 (Cure Rite)로 광중합기의 광강도를 측정하였다. 광중합기를 주문제작한 optical breadboard에 고정시킨 후 휴대용 spectroradiometer (CS-1000)를 이용하여 광중합기의 파장을 측정하였고, DSLR (Nikon D70s)을 이용하여 광중합기의 light diffusion을 사진 촬영하였다. 결과: 광강도 측정 결과는 차단막의 두께가 증가할수록 광강도가 유의하게 감소하였으나 할로겐 광중합기에서 1겹과 2겹 사이에는 유의차가 없었으며, 4겹 이상의 차단막을 투과할 때 광강도가 더 많이 감소하였다. 여러 겹의 차단막을 투과한 광중합기의 전체적인 파장 형태와 peak wavelength의 변화는 관찰되지 않았다. Light diffusion 사진 촬영 시, LED 광중합기에서는 차단막의 두께가 미치는 영향이 없었으나 할로겐 광중합기에서는 차단막을 4겹 사용했을 때부터 중합광이 조사되는 각도가 감소하기 시작하여 8겹 사용했을 때 통계적으로 유의하게 감소하는 것을 볼 수 있었다 (p < 0.05). 결론: 광중합형 복합레진을 광중합할 경우 감염 조절용 차단막이 찢어지는 경우를 대비하여 1겹으로 사용하기 보다는 2겹으로 사용하는 것이 환자간의 교차감염을 예방하는데 유리할 것으로 사료된다. Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

승용차량 추돌에서 후진등 필라멘트의 변형에 관한 연구

이홍석,김태훈,조건우 內務部 國立科學搜査硏究所 2002 國立 科學 搜査 硏究所 年報 Vol.34 No.-

개에서 디스템퍼 바이러스와 톡소플라즈마의 혼합 감염

강홍원,강상철,양형석,배종희,김재훈 한국임상수의학회 2004 한국임상수의학회지 Vol.21 No.1

A 3 month-old male dog with clinical signs of anorexia, soft stool, ocular and nasal discharge, cough and respiratory distress was submitted to the Cheju National University for diagnosis. At necropsy, tan to purple-red sublobar to lobar consolidations were presented in apical and cardiac lobe of lung. Histopathologically, severe diffuse bronchointerstitial pneumonia with necrotic bronchiolitis was noted in the lung. The demyelinating encephalitis and astrocytosis were presented in cerebellum and cerebrum. Numerous round, ovoid or cluster of tachyzoites were also identified in alveolar lumen, alveolar wall and cytoplasm of macrophages in the lung. The orgasnisms were demonstrated as Toxoplasma (T) gondii by immunohistochemistry. Intranuclear or intracytoplasmic eosinophilic inclusion bodies were seen in the glial cells of the cerebellum. Canine distemper virus (CDV) specific antigens were demonstrated in the cerebellum by the immunohistochemistry. In our knowledge, this is believed to be the first confirmed report of co-infection of CDV and T gondii in dog in Korea.

Mo 화학기상증착에 있어서 불순물 농도에 미치는 증착조건의 영향

배상석,서성교,홍은식,김승모,조미정,한혜정,이두성,김세훈,민석홍 국립7개대학공동논문집간행위원회 2001 공업기술연구 Vol.1 No.-

The thermal decomposition process of Mo(CO)_6 on chemical vapor deposition was investigated by analyzing the effects of deposition temperature, pressure, and reaction gas on the phase change of deposited films. Mo_2C was deposited at or below 350℃ due to the incompleteness of thermal decomposition of Mo(CO)_6, but Mo films was successfully deposited at 400℃ or higher temperatures. The variation of deposition pressure did not change the dependence of decomposition process on deposition temperature. The activation energy of surface reaction was 5.8 ㎉/mole.