점화시기가 LPG 엔진의 배기특성에 미치는 영향

한덕수,장영민,전봉준,김성준 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

As an automobile fuel, LPG has many environmental advantages compared to gasoline or diesel. However, current LPG engine which is provided with LPG fuel as gas form has lower power and worse fuel efficiency than gasoline engine. These problems of low power and bad fuel efficiency come from lower volumetric efficiency. Also there is a new rising problem of high failure ratio in an engine emission test. Although there are many factors which affect engine performance of exhaust gas emission, one believes that the fact that ECM of gasoline engine is used for LPG engine when retrofitting gasoline engine to LPG engine is one of the main problems, which lower engine power and emit more noxious gas due to wrong ignition timing. To solve these problems, one studied the effects ignition timing on the exhaust gas to find out the optimum condition of ignition timing. The experimental results show that noxious exhaust gas is reduced and engine power is increased if the optimum control of ignition timing is applied in accordance to the revolution speed of engine.

점화시기가 LPG 엔진의 배기특성에 미치는 영향

한덕수,장영민,전봉준,김성준 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.A

As an automobile fuel, LPG has many environmental advantages compared to gasoline or diesel. However, current LPG engine which is provided with LPG fuel as gas form has lower power and worse fuel efficiency than gasoline engine. These problems of low power and bad fuel efficiency come from lower volumetric efficiency. Also there is a new rising problem of high failure ratio in an engine emission test. Although there are many factors which affect engine performance of exhaust gas emission, one believes that the fact that ECM of gasoline engine is used for LPG engine when retrofitting gasoline engine to LPG engine is one of the main problems, which lower engine power and emit more noxious gas due to wrong ignition timing. To solve these problems, one studied the effects of ignition timing on the exhaust gas to find out the optimum condition of ignition timing. The experimental results show that noxious exhaust gas is reduced and engine power is increased if the optimum control of ignition timing is applied in accordance to the revolution speed of engine.

PLD 박막의 물리적 성질

한용진,조봉균,정재훈,이수빈,박해윤,이태기,채희백,홍진수 순천향대학교 기초과학연구소 1998 순천향자연과학연구 논문집 Vol.4 No.2

Thin amorphous carbon films were deposited by a Q-switched Nd;YAG 532nm with beam power density of ?? on the high purity graphite (99.7%). The pressure of vacuum chamber was ?? Torr. In order to estimate the quality of the Pulsed Laser Deposition films one of the most important optical properties, bandgap energy, was characterized by transmission and reflection in the range of the visible, and an optical direct bandgap energy of 2.45eV and indirect bandgap energy 0.36eV were obtained. Surface morphology of amorphous film was investigated by AFM (Atomic Force Microscopy). Its surface roughness is 70nm. Comparing our results with the published values in the literature we have confidence that our films show the good quality for optical properties.

韓國企業의 對中國直接投資 現況과 投資成果分析

한봉수,김상호 大邱大學校 社會科學硏究所 1998 社會科學硏究 Vol.5 No.4

한국기업의 대중국 투자성과를 알아보기 위하여 사용한 지표로는 투자동기의 달성, 현지 법인의 수익성, 현지법인의 성장성, 본사와의 관계, 합작파트너와의 관계등의 항목을 사용하였으며 그 결과는 업종별·투자지역별·규묘별로 상이한 양상을 보이고 있다. 제3국 수출 또는 대한국 수출을 목적으로 투자한 기업이 내수시장 진출을 목적으로 투자한 기업에 비하여 현지적응력 즉 투자성과가 높은 것으로 나타나고 있으며 지역별로는 청도, 천진 등 발해만 지역에 투자한 기업이 기타지역 투자기업에 비하여 높은 투자성과를 보이고 있다. 그리고 기업규모별로는 경공업중심의 소규모기업이 중공업중심의 대기업보다 투자수익성이 월등히 높았으며 또한 제조업이 비제조업보다 투자수익성이 높게 나타났다. 그러나 중국에 진출한 많은 한국기업들이 양적 확대에 버금가는 질적인 투자성과를 내고 있지 못함을 알 수 있었다.

濕式法에 依한 γ-MnO_2 製造에 關한 硏究(第2報) : Purification of Manganes Oxides by Acid Treatment

金鳳杰,姜泰範,韓正洙 慶熙大學校 1982 論文集 Vol.11 No.-

Studies on the effect of reaction temperature, reaction time and concentration of acid on the purification of manganese oxides was conducted to manufacture γ-MnO₂ available as dry cell depolarizer by wet process. The results obtained were follows: 1.When oxidized the precipitates of OH￣/Mn^++ mole ratio 2.2 by aeration at 13℃ for 6 hours, MnO₂content obtained 89.99%, which was identified as crystalline γ-MnO₂by X-ray diffraction analysis. 2. When manganese oxides was treated at 70℃ for 2hrs with 30% H₂SO₄and 30% HNO₃, the highest content, of MnO₂was obtained as 96.90% and 96.60%, respectively, which was identified as crystalline γ-MnO₂by X-ray diffraction analysis and different thermal analysis.

메조포어 물질을 이용한 TiO_2의 제조와 광촉매 산화반응에의 적용

이한수,윤봉국,우창수,김소영,He, NongYue,이호인 한국공업화학회 2003 응용화학 Vol.7 No.1

TiO_2-loaded mesoporous materials were prepared by sol-gel method. Mesoporous materials suppressed the phase transformation of TiO_2 from anatase to rutile and increased the bandgap of TiO_2 which was explained in terms of the quantum size effect. Several kinds of nano-sized TiO_2 with particle sizes of 5∼20 nm, were obtained through the removal of the mesoporous materials by etching in 2 M NaOH or the calcination under air condition. They showed good activites in the photocatalytic oxidation of 2-isopropyl-6-methyl-4-pyrimidinol.

PVA-ECC를 활용한 Half PC 복합체의 역학적 특성에 관한 실험적 연구

김재환,김영덕,김갑수,조봉석,장종호,김무한 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

ECC represents one particular class of HPFRCC, which are defined by an ultimate strength higher than their first cracking strength and the formation of multiple cracking during the inelastic deformation process. This study is to provide the fundamental data for the development of hybrid construction method such as the half PC(Precast concrete) reinforced by PVA-ECC, the mechanical properties of half PC according to the alteration of properties of PVA-ECC in terms of the type of fiber, Vr, S/M, placing height of PVA-ECC, are experimentally investigated. As the results. it is found that the half PCs of PVA-ECC have very higher mechanical performance in terms of yield load, strain capacity beyond yield point and maximum flexural load than that of mortar. Also, flexural crack in the half PCs of PVA-ECC are not localized at first crack and are growed to many micro crack, especially multiple cracking in specimen of P(12)-30-0.1ㆍ3 occurred.

도시 거주 노인 수면 습관 및 불면증상의 요인 : 인구학적,질병 및 정신증상의 관련성

홍진표,안준호,윤영국,박종익,이소영,함봉진,김장규,한오수,조맹제 대한신경정신의학회 2000 신경정신의학 Vol.39 No.6

연구목적 : 본 연구는 국내 노인의 습관을 조사하고 불면 증상과 연관 있는 인구학적, 질병학적 요인을 알고자 했다. 방 법 : 1997년 12월부터 1998년 1월까지 약 1개월에 걸쳐 2단계 층화집락표본추출의 역학조사법을 통해 선정된 3개 4개동 거주의 만 65세 이상 노인을 대상으로 수행되었다. 대상자 중 723명에서 등답을 받았으며 응답률은 73.8였다. 대학생인 설문조사요원들을 훈련시킨 뒤, 이들로 하여금 대상지역의 노인거주가정을 방문하여 개개 노인을 대상으로 반구조화된 면담으로 수면습관 및 불면증상 설문을 실시하였으며 그 외 한국어판 노인정신장애평가척도, 삶의 질 척도를 이용한 설문조사와 과거 질병력을 청취조사하게 하였다. 결 과 : 국내 노인들은 평균 오후 10시 16분에 자리에 누워 오전 5시22분에 일어나서 총 7시간 6분의 수면시간을 보였다. 노인의 11.7%가 거의 매일 밤 불면증을 14.8%가 간헐적 불면증을 호소하였다. 남자에서는 연령이 증가할수록 침상에 누워있는 시간이 증가하고, 또, 입면시까지 소요되는 시간과 수면 중의 각성회수가 증가되었으나 여성에서는 명확하지 않았다. 단변수 분석에서 요통, 중풍 병력의 환자에서 불면증상이 심했다. 다변량분석 결과 불면 증상과 관련 깊은 요인으로 남자에게서는 고령과 우울증상이 여자에게서는 남자의 위험요인에다 신체통증과 피부병력이 추가로 관련이 있었다. 결 론 : 지역 거주 노인에서 불면 증상은 매우 흔한 증상이며 우울증상과 명확한 상관관계를 보이고 있었다. 불면증을 극복하기 위해 불면증 위험요인의 인과관계에 대한 추후 연구가 필요하다. Objectives : The purpose of this study is to analyze sleep habit and investigate the association between insomnia and demographic, health and psycho-behavioral symptomatology in Korean urban elderly Method : A total of 723 community residents aged 65 years or older were surveyed by two stage, random cluster sampling method. The response rate was 76.2%. Interviewers performed door to door visits and administered a questionnaire about sleep, past medical history, and several scales as the Psychogeriatric Assessment Scale(PAS), the short form Quality of Life Scale (SF-36) and etc. Results : The mean scores are as follows : retiring time was ten-sixteen p.m., wake-up time was five twenty two a.m., duration of sleep was seven hours and six minutes. Among the elderly, 11.6% and 14.8% of the subjects reported chronic and intermittent difficulty in sleeping, respectively. The patients with back pain and history of stroke complained of more insomnia symptoms in univariate analysis. In ANCOVA analysis, insomnia symptoms were associated with an old age, depressive symptoms in male. Bodily pain and history of dermatologic disease were additional risk factors in female. Conclusions : The data suggest insomnia is one of most common health problems among elderly Koreans living in the community. Strong positive relationship between depressive symptoms and insomnia were found. Further research is needed to explore the causal relationship between insomnia and risk factors.

Evaluation of Fumigation Trials of Ethyl Formate in Greenhouse Cucumber to Eradicate Horticultural Insect Pests

Bong-Su Kim,Jin-Hoon Cho,Jeong-Oh Yang,Min-Su Kim,Han-Young Lee 한국응용곤충학회 2016 한국응용곤충학회 학술대회논문집 Vol.2016 No.10

Ethyl formate (EF), a methyl bromide alternative fumigant which is commercially used for quarantine and pre-shipment(QPS) purpose, has a potential to control various insect pests. Based on CTP (concentration × time products), we've firstly evaluated fumigation trials of EF on cucumber plants to eradicate horticultural insect pests in greenhouse. In the preliminary test, EF achieved 100% control of cotton aphid, western flower thrip and tobacco whitefly when CTP of EF was 4.4, 5.6 and 3.3 g h m-3, respectively. In 1300m3 scale cucumber greenhouse trial, EF was applied with 2g m-3 dosage for 15 hrs, and cotton aphid, western flower thrip and tobacco whitefly were completely controlled without phytotoxic symptom. EF fumigation could be suitable for greenhouse cultivation in terms of good efficacy on horticultural insect pests with labor-saving benefit than current insecticide spraying applications.

Enantioselective Carbonyl Reverse Prenylation from the Alcohol or Aldehyde Oxidation Level Employing 1,1-Dimethylallene as the Prenyl Donor

Han, Soo Bong,Kim, In Su,Han, Hoon,Krische, Michael J. American Chemical Society 2009 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.131 No.20

<P>Enantioselective transfer hydrogenation of 1,1-dimethylallene 1a in the presence of aromatic, alpha,beta-unsaturated, or aliphatic aldehydes 2a-i mediated by 2-propanol and employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, m-nitrobenzoic acid, and (S)-SEGPHOS delivers reverse-prenylation products 4a-i in good to excellent isolated yields (65-96%) and enantioselectivities (87-93% ee). In the absence of 2-propanol, enantioselective carbonyl reverse prenylation is achieved directly from the alcohol oxidation level to furnish an equivalent set of adducts 4a-i in good to excellent isolated yields (68-94%) and enantioselectivities (86-91% ee). Competition and isotopic labeling experiments suggest rapid alcohol-aldehyde redox equilibration in advance of carbonyl addition along with capture of the kinetically formed pi-allyl complex at a higher rate than reversible beta-hydride elimination-hydrometalation. This protocol represents an alternative to the use of allylmetal reagents in enantioselective carbonyl reverse prenylation and represents the first use of allenes in enantioselective C-C bond-forming transfer hydrogenation.</P>