냉간시동 중 스파크 점화 엔진의 탄화수소 배출에 관한 연구

홍명석,안철봉,장원 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

The emission characteristics of hydrocarbons during the cold start have been investigated. The measurements are focused upon the first 20 seconds of operation after starting with the engine and coolant initially at ambient temperature because this period has a major effect on HC emissions, over the FTP cycle, therefore decreasing cold start enrichment and decreasing the time to catalyst light-off are desirable. The engine examined is a 4-cylinder, 4-valve SI engine. The Motec engine control system is used to control ignition timing and fuel injector pulse width throughout the starting and warm-up transient. The engine started using the starter motor. Speciated HC emissions from the exhaust system of the engine have been obtained with 3 second time resolution during cold start using a exhaust gas sampling equipment. The emissions were initially enriched in light fuel alkanes and depleted in heavy aromatic species. The light alkanes feIl rapidly while the lower vapor pressure aromatics increased over a period of 50 sec. These results indicate early retention of low vapor pressure fuel components in the intake manifold and exhaust system. The atmospheric reactivity of the exhaust HC emissions for photochemical smog formation increases as the engine warms.

Pyridine 촉매하의 Cyclohexene의 Ozonolysis

홍원표,양현수,장자순,김철규 忠南大學校 産業技術硏究所 1988 산업기술연구논문집 Vol.3 No.2

Terminally functionalized molecules are essential building block for the formation of polymers by polycondensation reactions. It is the major goal of this research to establish new routes for the preparation of such molecules by selective oxidation reaction of cyclohexene, using ozone as an oxydizing agent. To this purpose, it has been explored, whether the usual course of the ozonolysis of olefins can be modified with the help of specific catalyst in order to introduce the desired functional groups. In particular, the ozonolysis of cyclohexene in hydrocarbon solvents and in the presence of pyridine has been tested with the goal of preparing molecules containing one aldehyde and one carboxylic acid group. Ozonolysis of cyclohexene in hydrocarbon solvents such as methylene chloride and pentane can be guided by catalysis with pyridine, such that the reactions afford desired molecules. In this manner, pyridine catalized ozone oxidation converted cyclohexene into the corresponding 6-oxohexanoic acid(45.87%), adipaldehyde(14.68%), and polymeric ozonide(39.45%), via the ω-formyl carbonyl oxides in CH₂Cl₂at 0℃.

잎들깨 수량과 단백질체 발현에 미치는 UV-B의 영향

홍성창,황선웅,장안철,신평균,장병춘,이철원 한국환경농학회 2006 한국환경농학회지 Vol.25 No.1

복합사이클 발전소의 효율에 관한 연구

전철호,장길홍 동아대학교 공과대학 부설 한국자원개발연구소 1993 硏究報告 Vol.17 No.2

The use of a combined cycle leads to an updating of power output, at the same time, increasing power plant efficiency. In this paper, the dissipation energy was calculated from two conventional and combined cycle processes, and then the efficiencies of many types of the combined cycle were compared. The efficiency of combined cycle power plant is evaluated by given data and its performance characteristics from the simulation. As a result, the total efficiency is increased as the compression ratio is increased.

새로운 방법에 의한 1,1-R,R'-2,3,4,5-테트라페닐-1-실라사이크로펜타디엔의 합성

주완철,흥장환,최석봉 성균관대학교 기초과학연구소 1988 論文集 Vol.39 No.1

A new synthesis of 1,1-R, R',-2, 3, 4, 5-tetraphenyl-1-silacyclopentadiene was described. It was synthesized from one-pot reaction of 1,4-dilithio-1, 2, 3, 4-tetraphenylbutadiene with R_nSiCl_4-n (n=0, 1, 2), where 1, 4-dilithio-1, 2, 3, 4-tetraphenyl butadiene was prepared from the reaction of diphenyl acetylene and lithium metal in ether solution with good yield (80∼85%).

Rieger syndrome : 증례보고 A CASE REPORT

이홍모,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.4

Rieger syndrome은 눈의 전안방 기형과 치아결손을 특징으로 하는 희귀한 유전질환으로 두 개안면 이상과 체성기형을 동반하기도 한다. Rieger syndrome은 상염색체 우선유전(autosomal dominant inheritance)되며, 발생빈도는 약 200,000분의 1이고, Paired-like homeodomain transcription factor2(PITX2)의 변이가 이 질환과 연관이 있는 것으로 보고되고 있다. 본 증례는 Rieger syndrome으로 진단 받은 4세 7개월 된 여아에 대한 것으로, 양안에 다동공증과 후태생환을 보이고, 측모두부계측에서 상악골 열성장이 나타났으며, 상악유측절치와 더불어 다수의 영구치 결손이 방사선 상에서 관찰되었다. 이 증례를 통하여 Rieger syndrome 환아의 구강 및 두 개안면의 소견을 관찰하고, 관련 문헌을 고찰하여 다소의 지견을 얻었기에 보고하는 바이다. Rieger syndrome is a rare, autosomal dominant gentic disorder characterized by malformation of the anterior chamber of the eye(goniodysgenesis) coincident with hypodontia. It may also be accompanied by a spectrum of dental, craniofacial and somatic anomalies. Mutations in paired-like homeodomain transcription factor2(PITX2) are associated with the syndrome, and its frequency in the general population has been estimated to be 1 : 200.000. In the present case, the patient, 4 year 7 month-old female, had posterior embryotoxon and polycoria. The maxilla was retrusive in cephalometric radiography. She had congenital missing on #52, #62 and some tooth germs of permanent tooth were not detected in panoramic radiography. The purpose of this paper is to report the dental and craniofacial findings and review the pertinent literature through this case.

성장기 아동의 single tooth scissors bite의 교정 치료: 증례 보고

김지인,현홍근,김영재,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2011 大韓小兒齒科學會誌 Vol.38 No.4

A scissors bite in the posterior teeth occurs when the upper teeth are positioned totally buccal to the lower teeth in centric occlusion, either unilaterally or bilaterally. This malocclusion can result from either excessive width of the maxilla or deficient width of the mandible, or sometimes combination of the both. Scissors bite, when left untreated without a proper dental intervention, interferes with the normal mandibular growth leading to a state where consequent disharmony in dental arch width evokes occlusal disturbances. Therefore, early preventive orthodontic treatment is necessary in patients with scissors bite. Scissors bite rarely involves anterior and posterior sites concuttently across the dental arch but usually affect single tooth. Even in the single tooth scissors bite cases, more likely to be met in the clinical fields, immediate dental intervention is indicated because continuous occlusal forces that exacerbate the already adverse axis of the posterior teeth. In this case study, patients with single tooth scissors bite, each 7, 14, 12, and 16 years old, were each treated with criss-cross elastic, fixed appliance, removable appliance, and miniscrews. With the proper selection of appliances appropriate to each specific cases, good treatment outcome can be achieved without resulting any side effects. 중심교합위의 상태에서 편측 혹은 양측으로 상악 구치부의 치아가 하악 구치부의 협측으로 위치한 경우를 scissors bite라 고 한다. 이는 상악의 폭경이 크거나 하악의 폭경이 좁은 경우 발생한다. Scissors bite의 경우 방치하게 되면 하악의 성장이 방해받게 되고 그 결과, 악궁 폭경의 부조화가 심해져 저작 장애를 일으킬 수 있으므로 조기 차단 교정이 반드시 필요하다. 실제 임상에서는 여러 치아의 scissors bite보다 최후방 구치 혹은 그 외 하나의 구치만의 single tooth scissors bite(STSB)을 보이는 경우가 많다. 이러한 STSB의 경우도 방치하게 되면 저작력으로 인하여 구치의 각도가 더욱 악화되므로 즉각적인 치료가 필요하다. 본 증례에서는 STSB를 보이는 7세, 14세, 12세, 16세의 환자에게 각각 criss-cross elastic, 고정성 장치, 가철성 장치, miniscrew를 사용하여 치료한 증례를 보고하였다. 각 환자의 증례에 적합한 장치를 잘 선택하여 사용한다면 치아를 정출시키는 등의 부작용을 야기하지 않고 양호한 결과를 얻을 수 있을 것이다

기관지 방선균증의 임상 1례

이은영,장태원,정만홍,옥철호,이규원,손창배,이지숙,신은경,서정아,백종현,김영옥 고신대학교의과대학 2007 고신대학교 의과대학 학술지 Vol.22 No.2

Actinomycosis is a chronic suppurative infection, whitch infiltrates mucosa-associated tissues. Thoracic, pelvic and cervicofacial infections of actinomyces are not uncommon, but endobronchial actinomycosis is rarely reported. We report a case of a 29 year old man who presented with a recurrent pneumonia and chronic cough. Fiberoptic bronchoscopy revealed occlusion of the right. lower medio-basal segment bronchus with exophytic endobronchial mass. The diagnosis was confirmed histologically by demonstration of sulfur granules in the bronchoscopic biopsy of the mass. Intravenous administration of amoxacillin and clindamycin followed by oral amoxacillin and clindamycin therapy resulted in complete recovery.

자연정화공법에 의한 인공습지 하수처리장에서 최적 수생식물의 선정

서동철,장병일,조인성,임석천,이홍재,조주식,김홍출,허종수 한국환경농학회 2006 한국환경농학회지 Vol.25 No.1

상악 제2유구치와 상악 제1대구치의 치관 형태: 치아계측학적 연구

김지인,현홍근,김영재,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2011 大韓小兒齒科學會誌 Vol.38 No.4

The basic structure of the primary crowns usually resemble their succeeding permanent teeth. However, maxillary second primary molars resemble ipsilateral first permanent molars. Accordingly in this study, odontometric data of the two teeth was obtained, then analyzed to verify the morphological relationship and sex difference between the two teeth. Dental study casts were examined for their mesiodistal and buccolingual width of the crowns, diameter of each cusps, and intercuspal distances. Photographs of the crowns were taken to measure the angles between each cusp tip. The results are as follows : 1. In boys, PrI, PaI, DBC angle, and MBC angle did not show any statistically significant difference between the two teeth(p>0.05), and moderate level of correlations were observed. 2. In girls, crown index, DBC angle, and MBC angle of the two teeth did not show any statistically significant difference(p>0.05), and moderate level of correlations were recognized. 3. Measurements that did not show statistically significant difference between the two teeth in both boys and girls were DBC angle and MBC angle(p>0.05). In DLC angle, however, statistically significant difference was observed(p<0.01). 4. Most of the measurements showed sex differences, except DBC angle, which did not show any sex difference in both teeth(p>0.05). 유치 치관의 기본적인 구조는 대개 계승 영구치를 닮는다. 그러나 제2유구치는 계승 영구치인 제2소구치보다 오히려 제1대 구치와 더 유사한 경향이 있다. 이에 본 연구는 한국인에서 상악 제2유구치와 제1대구치의 치아계측학적 자료(odontometric data)를 얻어 두 치아의 형태와 크기 사이의 연관성을 살펴보고, 나아가 남녀간의 차이점 유무를 고찰해 보고자 하였다. 남아 150명, 여아 150명 총 300명의 모형을 이용하여 상악 제2유구치와 상악 제1대구치의 근원심 치관 폭경, 협설측 치관 폭경, 각 교두의 직경, 교두정간 거리를 계측하였고, 치관의 교합면 사진을 촬영하여 각 교두정 사이의 각도를 측정하여 다음과 같은 결과를 얻었다. 1. 남아에서 Protocone index, Paraconeindex, Distobuccal cusp(DBC)각, Mesiobuccal cusp(MBC)각은 상악 제1대 구치와 제2유구치 사이에 통계적 유의차가 관찰되지 않았고(p>0.05), 중등도의 상관관계가 확인되었다. 2. 여아에서 crown index, Distobuccal cusp(DBC)각, Mesiobuccal cusp(MBC)각은 상악 제1대구치와 제2유구치 사 이에 통계적 유의차가 관찰되지 않았고(p>0.05), 중등도의 상관관계가 확인되었다. 3. 남, 여 모두에서 Distobuccal cusp(DBC)각, Mesiobuccal cusp(MBC)각은 두 치아 사이에 유의할만한 차이를 보이 지 않았고(p>0.05), Distolingual cusp(DLC)각에서는 통계적 유의차가 관찰되었다(p<0.01). 4. 대부분의 계측치에서 남녀 차이를 나타냈지만, Distobuccal cusp (DBC)각은 상악 제1대구치와 제2유구치 모두에서 남녀 차이를 보이지 않았다(p>0.05).