유산 완충용액의 pH 및 포화도 변화에 따른 법랑질 내 수산화인회석 결정 형태의 변화

전영의,정일영,노병덕,이찬영 大韓齒科保存學會 2007 Restorative Dentistry & Endodontics Vol.32 No.6

Since it was reported that incipient enamel caries can be recovered, previous studies have quantitatively evaluated that enamel artificial caries have been remineralized with fluoride, showing simultaneously the increase of width of surface layer and the decrease of width of the body of legion. There is, however, little report which showed that remineralization could occur without fluoride. In addition, the observations on the change of hydroxyapatite crystals also have been scarcely seen. In this study, enamel caries in intact premolars or molars was induced by using lactic acidulated buffering solutions over 2 days. Then decalcified specimens were remineralized by seven groups of solutions using different degree of saturation (0.212, 0.239, 0.301, 0.355) and different pH (5.0, 5.5, 6.0) over 10 days. A qualitative comparison to changes of hydroxyapatite crystals after fracturing teeth was made under SEM (scanning electron microscopy) and AFM (atomic force microscopy). The results were as follows : 1. The size of hydroxyapatite crystals in demineralized area was smaller than the normal ones. While the space among crystals was expanded, it was observed that crystals are arranged irregularly. 2. In remineralized enamel area, the enlarged crystals with various shape were observed when the crystals were fused and new small crystals in intercrystalline spaces were deposited. 3. Group 3 and 4 with higher degree of saturation at same pH showed the formation of large clusters by aggregation of small crystals from the surface layer to the lesion body than group 1 and 2 with relatively low degree of saturation at same pH did. Especially group 4 showed complete remineralization to the body of lesions. Group 5 and 6 with lower pH at similar degree of saturation showed remineralization to the body of lesions while group 7 didn't show it. Unlike in Group 3 and 4, Group 5 and 6 showed that each particle was densely distributed with clear appearance rather than crystals form clusters together. 법랑질 초기 우식이 회복된다는 것이 보고된 이래 법랑질에 대하여 불소를 첨가한 상태에서 행했던 이전의 연구들은 법랑질 인공우식의 재광화가 표면층의 증가와 함께 병소본체의 폭 감소가 일어난다는 정량적인 평가는 많이 하였으나 불소를 첨가하지 않은 상태에서는 재광화가 일어났다는 연구는 부족하였고, 또 수산화인회석 결정의 입자 변화에 대한 관찰도 미비하였다. 본 연구는 탈회나 균열이 없는 소구치 및 대구치를 대상으로 탈회 완충용액을 이용하여 법랑질을 2일간 탈회시키고, pH와 포화도가 상이한 7가지 유산 완충용액으로 10일 동안 재광화를 유도한 후 치아를 파절시켜 수산회인회석 결정의 변화를 원자현미경과 주사전자현미경을 이용하여 정상적으로 비교 관찰하여 다음과 같은 결과를 얻었다. 1. 탈회된 부위에서 관찰된 수산화인회석 결정은 정상적인 수산화인회석 결정보다 크기가 작았으며 결정 사이의 공간이 증가하면서 결정들이 불규칙하게 존재하는 것이 관찰되었다. 2. 재광화된 부위에서는 탈회에 의하여 형성된 빈 공간에 작은 수산화인회석 결정이 새로 침착되는 양상과 결정들이 융합하여 다양한 모습을 갖는 더 커진 결정들을 관찰할 수 있었다. 3. 동일한 pH에서 포화도가 더 높은 3군, 4군은 1군, 2군에 비하여 표면층에서부터 병소본체까지 작은 결정들이 모여 큰 cluster를 형성하였으며 특히 4군에서는 병소본체까지 완전한 재광화가 일어났다. 비슷한 포화도에서는 pH가 더 낮은 5군, 6군은 7군에 비하여 병소본체까지 재광화가 일어났으며 3군, 4군처럼 결정들이 모여 cluster를 형성하기보다는 개개의 입자들이 뚜렷한 외형을 가지며 매우 치밀하게 분포되어 있었다.

이산화질소의 연직분포 특성에 관한 연구

전의찬,이성기 조선대학교 환경연구소 1991 環境公害硏究 Vol.8 No.-

Recently, a number of high-rise buildings have been constructed in big cities such as Seoul. The air pollution levels at these buildings are expected to be generally different from those at the ground level. The purpose of this study is to show the vertical distribution of nitrogen dioxide(NO_(2)) in Seoul City. The concentration of NO_(2) with height were measured at the Korea Exhibition(KOEX) building(54 stories), one of the new high storied buildings. At the same time, the vertical variation of the temperature were measured and the effect of the atmospheric stability on the vertical distribution of air pollutants was analyzed. The result are as follows; 1) In the morning. the minimum concentration was found at 50m above the ground, and the maximum value at the ground level and 110m above the ground. In the afternoon, the minimum value was found at 110m above the ground, and the maximum value at 50m above the ground. At night, the minimum value was found at 50m above the ground, and the maximum value at 160m above the ground. 2) The minimum value of daily average concentration was found at 50m above the ground, and the maximum value at the ground level and 160m above the ground. 3) The daily variation of air pollution concentration turned out to have a close relationship with the atmospheric stability. The NO_(2) concentration was higher in the morning exceeding the long-term air quality standard.

이산화티타늄계 광촉매를 이용한 톨루엔의 처리 특성

전의찬,송민종,김전희 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

각종 급ㆍ만성의 건강장해를 일으킬 뿐만 아니라, 광화학 반응에 의해 오존을 형성하는 것으로 알려진 휘발성유기화합물 중 대표적인 물질인 톨루엔을 광촉매산화법으로 처리할 경우 최적 처리조건을 분석하고자 광촉매의 결정구조, 광원의 세기, 전자수용체로서 산소의 유무 등에 따른 톨루엔의 처리효율을 분석하였다. 실험결과 루틸령 결정구조에 비해 아나타제형 결정구조를 갖는 이산화티타늄의 톨루엔 처리효율이 높게 나타났으며, 광원의 세기가 높을수록 전자수용체로서 산소가 존재할 경우 높은 처리효율을 나타내었다. 시간과 공간적인 제약으로 물, 오존 그리고 증기와 같은 다양한 전자수용체가 존재할 경우의 톨루엔의 처리효율을 파악하지 못하였으며, 온도, 습도 및 촉매활성에 영향을 주는 여러 가지 인자들을 대상으로 그것들의 변화에 따른 처리효율의 고찰을 못하였다. 앞으로 보다 효율적인 이산화티타늄계 광촉매의 제조방법 개발과 이산화티타늄계 광촉매를 이용한 다양한 VOC 처리방법의 개발이 요구된다. An available methods for abating VOC(including Toluene) are thermal or catalytic incineration, liquid absorption, solid adsorption, condensing, membranes, biodegradation and plasma discharge, but a number of defects are these VOC abating methods, including ; requires a auxiliary fuel, generate secondary pollutants(waste catalysts, waste absorbents, waste adsorbents, ozone, etc.), a large scale, etc.. But photoactive catalysts, when illuminated with UV-light, generate highly reactive radicals that can oxidize the organic contaminants in gas. One methods to increase the efficiency of the process, and thereby reduce the light energy requirement, is by developing more active catalysts. Because of, ball type TiO2 catalyst were obtained commercially and/or prepared in laboratory were examined for their photoacivity, and they are TiO2 added some annex(Al203, SiO2, KsO, P205, etc.). The organic compounds used to identify the best photocatalysis condition were toluene. This study also examined the impact of catalyst structure, light intensity, existence of oxygen as an electron acceptor and Toluene initial concentration on the reaction kinetics. Labratory experiments were performed to investigate TiO2 photocataysis for treating test gas contaminated with Toluene. and TiO2 photocatalysis efficiency for mineralization of Toluene is also evaluated. The photooxidation of Toluene was carried out in a photocatalytic reactor at room temperature. I performed Toluene photocatalytic oxidation experiments using a single-pass annular reactor. The organic-contaminated gas was prepared in teflon sampling bag(25L) and passing through photocatalytic reactor by vacuum pump which is located reactor outlet. The Toluene diluted with mixture air or nitrogen gas. Flow rates for test gas stream were controlled by micro flow meter going out the reactor. The reactor illuminated with 15W near-UV lamp, BLB lamp or Fluorescent lamp. The light intensity at the catalyst surface were estimated to be 0.8 to 6㎽ ㎝-2s-1. The inner cell of the reactor was packed with ball type titanium dioxide(φ 6㎜). Toluene was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor outlet by gas-tight syringe. TiO2 photocataysis for treating test gas contaminated with Toluene. and TiO2 photocatalysis efficiency for mineralization of Toluene is also evaluated. Using the anatase type photocatalyst, Touene conversion rate is greater than that of rutile(86.1% conversion of 100ppmv Toluene using anatase type photocatalyst, 78% conversion of 100ppmv Touene using rutile type photocatalyst at 0.5L/min) Effect of light intensity on the rate of Toluene photocatalytic decomposition was investigated by three type lamps within the reactor. When light intensity to increase, the Toluene conversion rate to increase. Using the BLB lamp showed higher activity than the Fluorescent lamp, but UV lamp showed the hight photocatalytic activity(19.1% conversion of 100ppmv Toluene with Fluorescent lamp, 60.4% conversion of 100ppmv Toluene with BLB lamp, 86.1% conversion of 100ppmv Toluene with UV lamp at 0.5L/min). Experiments with added oxygen as an electron acceptor improved the reaction rate considerably(86.1% conversion of 100ppmv Toluene without oxygen, 62.5% conversion of same Toluene concentration with mixture air at 0.5L/min).

이산화티타늄계 광촉매를 이용한 벤젠의 처리 특성

전의찬,송민종,김전희 동신대학교 환경연구소 1999 환경연구 Vol.4 No.1

An available methods for abating VOC(including Benzene) are thermal or catalytic incineration, liquid absorption, solid adsorption, condensing, membranes, biodegradation and plasma discharge, but a number of defects are these VOC abating methods, including ; requires a auxiliary fuel, generate secondary pollutants(waste catalysts, waste absorbents, waste adsorbents, ozone, etc.), a large scale, etc.. But photoactive catalysts, when illuminated with UV-light, generate highly reactive radicals that can oxidize the organic contaminants in gas. One methods to increase the efficiency of the process, and thereby reduce the light energy requirement, is by developing more active catalysts. Because of, ball type TiO₂ catalyst were obtained commercially and/or prepared in laboratory were examined for their photoacivity, and they are TiO₂ added some annex(Al₂O₃, SiO₂, KsO, P₂O_(5), etc.). The organic compounds used to identify the best photo catalysis condition were benzene. This study also examined the impact of catalyst structure, light intensity, existence of oxygen as an electron acceptor and Benzene initial concentration on the reaction kinetics. Labratory experiments were performed to investigate TiO₂ photo catalysis for treating test gas contaminated with Benzene. and TiO₂ photo catalysis efficiency for mineralization of Benzene is also evaluated. The photo oxidation of Benzene was carried out in a photo catalytic reactor at room temperature. I performed BTX photo catalytic oxidation experiments using a single-pass annular reactor. The organic-contaminated gas was prepared in Teflon sampling bag(25L) and passing through photo catalytic reactor by vacuum pump which is located reactor outlet. The BTX diluted with mixture air or nitrogen gas. Flow rates for test gas stream were controlled by micro flow meter going out the reactor. The reactor illuminated with 15W near-UV lamp, BLB lamp or Fluorescent lamp. The light intensity at the catalyst surface were estimated to be 0.8 to 6mW cm-2s-1. The inner cell of the reactor was packed with ball type titanium dioxide(Ø 6mm). Benzene was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor outlet by gas-tight syringe. TiO₂ photo catalysis for treating test gas contaminated with Benzene. and TiO₂ photo catalysis efficiency for mineralization of Benzene is also evaluated. Using the anatase type photo catalyst, Benzene conversion rate is greater than that of rutile(92% conversion of 100ppmv Benzene using anatase type photo catalyst, 80% conversion of 100ppmv Benzene using rutile type photo catalyst at 0.5L/min) Effect of light intensity on the rate of Benzene photo catalytic decomposition was investigated by three type lamps within the reactor. When light intensity to increase, the Benzene conversion rate to increase. Using the BLB lamp showed higher activity than the Fluorescent lamp, but UV lamp showed the hight photo catalytic activity(26% conversion of 100ppmv Benzene with Fluorescent lamp, 63.5% conversion of 100ppmv Benzene with BLB lamp, 92% conversion of 100ppmv Benzene with UV lamp at 0.5L/min). Experiments with added oxygen as an electron acceptor improved the reaction rate considerably(92% conversion of 100ppmv Benzene without oxygen, 66.1% conversion of same Benzene concentration with mixture air at 0.5L/min). The Benzene conversion rate begins to decrease while Benzene initial concentration begins to increase. We have thus concentrated our effects on the study of Benzene degradation kinetics in vary initial Benzene concentration.

農村에 있어서의 腸管系寄生蟲의 豫防對策 三槽式腐敗槽便所의 살아있는 寄生蟲卵 및 病原性腸內細菌의 環境汚染 遮斷效果

金東燦,李溫永,金舜姬,韓義正,金南洙 國立保健硏究院 1977 국립보건연구원보 Vol.14 No.-

'지방의제 21 실천계획' 수립을 위한 시민 환경의식 조사 연구

전의찬,사재환,조순철 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

數種 根管充塡用 sealer의 根管密閉機能에 대한 比較硏究

洪燦義 단국대학교 1987 論文集 Vol.21 No.-

The purpose of the present study was to compare the sealing ability of several root canal sealers commonly used in endodontic therapy. One hundred maxillary anterior canals from artificial Epoxy resin block were employed and prepared to a size 50 K-file in a conventional method. The canals were divided into five groups of twenty each and obturated with the following materials. Z.O.E. cement, Tubliseal, Nogenol, Calcipulpe, and Vitapex. After canal obturation, all the specimens were immersed in 2% Methylene blue dye solution and stored in an incubator at 37℃. At the end of 24 hours, 2 days, 3days, 5days, 7days, 10days, and 14days, ald the specimens were removed from the dye solution in order to evaluate the dye penetration. The sealing ability was evaluated by measuring the distance of dye penetration from the apical foramen into the pulp chamber under a macroscope. The results were as follows; 1. All the tested sealers showed varying degree of dye penetration. 2. All the tested sealers showed increasing pattern in dye penetration over time. 3. Nogenol, Tubliseal, and Vitapex showed a better sealing ability than Z.O.E cement or Calcipulpe. 4. Nogenol showed the best sealing ability among the tested sealers, and Calcipulpe showed the worst within 2 weeks. 5. Vitapex showed nearly the same sealing ability as Tubliseal.

환경기초시설 중 하·폐수처리과정으로부터의 GHG 배출량 예측 : 광주·전남지역을 중심으로 Kwang ju·Chollanado

전의찬,김전희,송민종 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

본 연구는 환경기초시설 중에서 생활하수와 산업폐수 처리장에서 발생하는 특히 광주·전남 지역을 중심으로 온실가스의 배출량과 장래 저감 잠재성을 평가하고, 기후변화협약을 대비한 국가 Inventory의 기초자료로 이용될 수 있도록 하였으며, 결론적으로 하ㆍ폐수부문에서 온실가스 배출 잠재성을 감소시키기 위한 방안으로 먼저 하수 및 폐수의 체계적인 수집이 이루어져야 하며, 수집된 하ㆍ폐수는 반드시 적절한 처리과정을 통하여 수계에 배출되어져야 한다. 또한 적절한 처리과정 중에 배출되는 온실기체의 대기 중으로의 누설을 억제하고 회수율을 높이는 관리대책이 수립되어야 하며, 회수율을 높이는 대책은 하ㆍ폐수부문에서 온실가스 배출 잠재력에 대한 저감율에 대하여 좀더 효율적임을 알 수 있다. 또한 상기와 같은 저감방법 외에도 하ㆍ폐수부문에서의 온실가스 저감잠재력을 위하여 정부는 온실가스 배출량을 계산하는데 필요한 여러 가지 자료를 확보하고, 좀더 신뢰할 수 있는 온실가스 배출량을 산출하며, 이들 자료를 토대로 정부는 하ㆍ폐수부문에서의 온실가스 저감잠재력을 위하여 연차적으로 관리대책을 설정해야 한다. 그리고 이에 대한 검중체계를 마련하여 전ㆍ후 효과분석을 해야 할 것이다. This study evaluated greenhouse gas(GHG) emissions and future reduction potential emitted from domestic and industrial wastewater treatment system in Kwangju city and Chollanamdo. For decreasing of GHG emissions potential, systematic collection method of domestic and industrial wastewate is established and collected domestic and industrial wastewater is treated reasonal wastewater treatment process. GHG which is leak from wastewater treatment process to air was controled, Control policy which are increasing recovery ratio was established. In addition to decreasing method, Government make sure of variable data fro estimating GHG emissions quality and evaluated GHG emissions quality reliable method.

비구개관낭종에 관한 X선학적 연구

전찬덕,이상래,황의환 大韓口腔顎顔面 放射線學會 1993 Imaging Science in Dentistry Vol.23 No.1

The purpose of this study was to evaluate the clinical and radiographic features of 35 cases of nasopalatine duct cyst by means of the analysis of periapical and/or occlusal radiograms in 35 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chonbuk National University. The obtained results were as follows: 1. The incidence of nasopalatine duct cysts was higher in males(74.3%) than in females(25.7%). 2. The nasopalatine duct cysts were the most frequently occurred in the 4th decades(34.3%). The 6th and 7th decades(17.1%, 17.1%) were next in order to frequency followed by the 5th decades(14.3%), the 3rd decades(8.6%), the 2nd decades(5.7%), and 8th decades(2.9%). 3. In the signs and symptoms of nasoplatine duct cysts, 25.7% were swelling, 17.1% were swelling and tenderness, 20.0% were swelling and pain, and 37.2% were a symptom. 4. In the shape of nasopalatine duct cysts, 40.0% were round type, 48.6% were oval type, and 11.8% were heart type, In symmetry of the nasopalatine duct cysts to the median palatine surture, 85.7% were symmetry, 14.3% were asymmetry. 5. In the width of nasopalatine duct cysts, 11.4% were 6-10mm, 48.6% were 11-20mm, 25.7% were 21-30mm, and 14.3% were 31-40mm. 6. In the periphery of nasopalatine duct cysts., 82.9% were distinct, 17.1% were relatively distinct. 7. In the change of root, 51.5% were intact, 17.1% were root divergence, 20.0% were root resorption, and 11.4% were root divergence and resorption.

광주광역시의 점오염원 배출자료체계 구축에 관한 연구

전의찬,송민종 東新大學校 1997 論文集 Vol.9 No.-

For the development of point source emission inventory system in Kwangju, we reserched into point source location, physical characteristics and fuel consumption for air pollutant discharge facilities classification(class 1 to class 3). And we estimated quantity of air pollutants by source scale, drawing up distribution chart of air pollutants. It was found that there were 51 point sources located in Kwangju and Metal products are the most numerous industry. Also, Emmision quantity of air pollutants were estimated at SO_2 4,224ton/yr, NO_2 1,004ton/yr and TSP 76ton/yr and 'Rubber and plastic products' emited the most air pollutants in Kwangju.