메탄 공기 층류 부분 예혼합화염에서 예혼합 정도에 따른 화염구조와 질소산화물의 배출에 미치는 영향에 관한 연구

오정석(Jeong Seog Oh),정용기(Yong Ki Jeong),전층환(Chung Hwan Jeon),장영준(Young June Chang) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11

It is shown that the effect of variable parameters on flame structures and NOx emissions in the laminar<br/> partially premixed methane-air flames with a co-axial Bunsen burner. Objectives of this paper is to<br/> understand the effects of flow variables on NOx emissions and the flame structure with OH<br/> chemiluminescence, including reconstructed image by abel inversion processing at each conditions. A fuel<br/> flowrate of 200 [cc/min] was fixed and the amount of air was varied from 400 to 1200 [cc/min]. The<br/> experimental variables were equivalence ratio( ), fuel split percentage( ) and inner tube recess(x/D). Flow<br/> conditions were ranged from 1.36~4.76(equivalence ratio), 50~100(fuel split percentage) and 0~20(inner<br/> tube recess). NOx analyzer and ICCD camera with a OH filter were used as a main experimental<br/> apparatus. In addition, Abel inversion, which is a kind of tomography and valuable to estimate a<br/> two-dimensional structure of co-axial flames from cubical information, was employed for combustion<br/> diagnostics. Results from this study indicate that the main effects depend on equivalence ratio and next<br/> sigma, x/D for NOx production and OH formation. Throughout Abel inversion, we could affirm the<br/> maximum position and the tendency of OH radical intensity by variants at five axial heights above the<br/> burner exit.

메탄/공기 층류 부분예혼합화염의 상세 라디칼(OH*, CH* 그리고 C₂*) 정보와 배기매출물에 관한 실험적 연구

정용기,오정석,전충환,장영준,Jeong Yong Ki,Oh Jeong Seog,Jeon Chung Hwan,Chang Young June 대한기계학회 2005 大韓機械學會論文集B Vol.29 No.2

An experimental study was performed to investigate the effects of partially premixing, varying the equivalence ratios from $0.79{\sim}{\infty}$, on NOx emissions and chemiluminescence of excited $OH^{\ast},\;CH^{ast}\;C_2^{\ast}$ radicals in laminar partially premixed flames. the signal from the electronically excited state of $OH^{\ast},\;CH^{ast}\;C_2^{\ast}$ was detected through a band pass filter with a photo multiplier tube, which are processed to the intensity ratio ($C_2^{\ast}/CH^{\ast},\;C_2^{\ast}/OH^{\ast},\;and\;CH^{\ast}/OH^{\ast}$) to reveal the correlation with local equivalence ratio. And measurements of NOx emission were made to investigate the relationship between visible flame appearance, chemiluminescence, and EINOX. The results demonstrated that (1) the flames at ${\phi}<1.59$ exhibited classical double flame structure, at ${\phi}>4.76$, the flames exhibited diffusion flame structure, and the intermediate flames at $1.59<{\phi}<4.76$ was a merged flame, (2) the $OH^{\ast}$ peak was located inside the $CH^{\ast}\;and\;C_2^{\ast}$ radical for all measured conditions and the emission intensity ratio of $C_2^{\ast}/CH^{\ast}\;and\;C_2^{\ast}/OH^{\ast}$ were identified as good marker for local equivalence ratio over a range of ${\phi}=0.79{\sim}1.2\;and\;CH^{\ast}/OH^{\ast}\;is\;0.79<{\phi}<1.9$. However, it was difficult to predict the equivalence ratio in partially premixed flames using this system for ${\phi}>2.38$, (3) the minimum NOX emission index (EINOx) is obtained for a equivalence ratio of 3.19 in the intermediate flames.

이중동축 메탄/공기 층류 부분 예혼합화염에서의 화염구조와 자발광 배출 특성 안쪽관 연료주입의 영향

오정석(Jeong Seog Oh),정용기(Yong Ki Jeong),전충환(Chung Hwan Jeon),장영준(Young June Chang) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11

In this study, the effect of central fuel injection on a coaxial laminar CH₄/air flame was experimented at the defined premixing condition(φ=1.90, σ=50/75/100%, x/D=10). The partial premixing parameter are the equivalence ratio that total fuel is fixed at 200cc/min, the fuel split degree which means the percentage of fuel entering the outer tube to the total amount, and the mixing distance indicating the nonreactant mixture's homogeneity between inner tube top and burner exit. The object is to investigate the flame structure and chemiluminescence characteristics of laminar partial premixed flame as changing mixing parameters. The radical signal was acquired from ICCD camera and PMT. Each intensity was compared with Abel inverted value for measuring the effect of background light on the peak signal location and the intensity at central preheat zone. The results show that the peak location of each radical was broaden as the fuel split degree increasing because the mixing quality was enhanced. and OH* is a good indicator for flame front between reaction and preheat zone. At last C₂* has the same tendency with CH* but a thinner reaction zone than CH* due to a rapid decay on the burned gas side.

ESO기법을 이용한 신뢰성 기반 형상 최적설계

오영규,박재용,황승민,임민규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based shape optimization (RBSO) using the evolutionary structural optimization (ESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. The deterministic optimization (DO) is obtained without considering uncertainties related to uncertainty parameters. However, the RBSO can consider the uncertainty variables because it has the probabilistic constraints. In order to determine whether the probabilistic constraint is satisfied or not, simulation techniques and approximation methods are developed. In this paper, the reliability-based shape design optimization method is proposed by utilizing the reliability index approach (RIA), performance measure approach (PMA), single-loop single-vector (SLSV), adaptive-loop (AOL) are adopted to evaluate the probabilistic constraint. In order to apply the ESO method to the RBSO, a sensitivity number is defined as the change in the displacement. Numerical examples are presented to compare the DO with the RBSO. The results of design example show that the RBSO model more reliable than deterministic shape optimization.

흰쥐 하부뇌간에서의 Cholecystokinin octapeptide의 분포

오석희,박매자,조희중,주강 慶北大學校 醫科大學 1990 慶北醫大誌 Vol.31 No.3

흰쥐의 하부뇌간에서 cholecystokinin-octapeptide(CCK-8)의 분포를 관찰하기 위하여 Peroxidase-Antiperoxidase법으로 염색하여 관찰해 본 결과 다음의 많은 부위에서 CCK-8양성세포 및 양성섬유를 관찰할 수 있었다. 중뇌: 흑질, 복측피개야, n. linea rostralis, 중심회백질, n. parabrachialis colliculi posterioris, 하구 및 외측모대핵에서 CCK-8양성세포가 관찰되었고 양성섬유의 경우 각간핵, n. parabrachialis co lliculi posterioris, parabigeminal n., 하구, 외측모대핵 및 배측 봉선핵에서 관찰되었다. 후뇌: CCK-8양성세포는 n. parabrachialis lateralis, n. of group O, 고속핵, 최후야 및 삼차신경 척수로핵에서 분포하였고, 양성섬유는 교봉선핵, 교핵, n. parabrachialis lateralis, 청반핵, n. parolivaris superior, 와우신경핵, 고속핵, 미주신경배측핵, inferior olivary complex, 박속핵, 설상속핵, 삼차신경척수로핵 및 망양체의 일부등에서 존재하였다. In order to investigate the distribution of immunoreactive cholecystokinin octapeptide(CCK-8)-containing neurons in the lower brain stem of the rat, brains of the rats perfused with fixative were extirpated, fronzen sectioned and processed for Peroxidase method. The results obtained were as follows. Mid brain; CCK-8-containing cells were found in the ventral tegmental area, substantia nigra, nucleus(=n.) linea rostralis, substatia grisea centralis, n. parabrachialis lateralis, inferior colliculus and lateral lemniscus and fibers were distributed in the interpeduncular n., n. linea rostralis, ventral tegmental area, substantia nigra, superior colliculus, substantia gricea centralis, n. parabrachialis, lateralis parabigeminal n., inferior colliculus, lateral lemniscus and n. raphe dorsalis. Pons and Medulla oblongata; CCK-8-containing cells were detected in the n. parabrachialis lateralis, n. of group O, n. tractus solitarii, area postrema and n. tractus spinalis nervi trigemini, and fibers were found in n. centralis superior, pontine n., n. parabrachialis lateralis, locus coeruleus, n. parolivaris superioris, cochlea n., n. tractus solitarii, dorsal n. of vagus nerve, inferior olivary compex, n. gracilis, n. cuneatus, n. tractus spinalis nervi trigemini and reticular formation.

THMs 저감을 위한 고도정수처리 기술 연구

강석규,오재원 大田産業大學校 1999 한밭대학교 논문집 Vol.16 No.1

At the time when the application of advanced water treatment process is required, a pilot plant consisting of ozonation, granular activated carbon(GAC) column and conventional water treatment treating 30㎥/day was conceived. As Daechung lake was in eutrophicated state, treatment of the polluted raw water by the pilot plant was studied. Especially, TOC removal which is the THM precursor and the optimum operating condition were investigated. The results obtained were as follows ; 1. Advanced water treatment using the pilot plant was effective for reducing THM formation potential : at the early stage - 90% reduction, after 8, month - 30% reduction were achieved. 2. Removal efficiency of organic pollutants(COD_Mn, TOC, DOC) by ozonation was about 10%, and it was not particularly sucessful comparing to GAC alone. 3. In order to remove such slow diffusivity pollutants as DOC, TOC in GAC column, it was confirmed that the bed depth was one of the most important design parameters. 4. For GAC column, imported GACI showed the better removal efficiency than GAC2(domestic product).

학습목표 성취를 위한 CAI 프로그램의 개발

주경수,권오석 순천향대학교 1994 논문집 Vol.17 No.1

We planned 5 grade mathematics fraction by CAI program in order to help the accomplishment of learning by the correct knowledge of learning objection. We are embodied by making use of GREAT with authoring tools. This was that heteogeneous students were able to shorten learning period in the circumstances of learning in a class room, to extend remarkably personal ability with individual learning adjust to each student. In addition to, we made a program so as to compensate for high level process for superior student, the supplementation of learning less for inferior students.

합성하수를 이용한 금속 막의 정밀여과 특성 및 막 오염 제어

정종태,김종오,김학균,김석구,이용재 7개 국립대학교 환경연구 논문집 공동발행 위원회 2004 공업기술연구 Vol.4 No.-

This study was to evaluate the filtration performance of metal membrane with synthetic wastewater and to investigate the effective control of membrane fouling using ozone backwashing. The increase of substrate concentration caused the increase of cake layer resistance and total resistance, however, plugging resistance decreased. Total resistance of metal membrane was mainly attributed to the permeate resistance of cake layer, which was formed by deposited particles from the physico-chemical interactions of solids on membrane surface. Intermittent ozone backwashing was more effective then the air backwashing for fouling reduction. The permeation flux recovery of air backwashing decreased over 50%, however, ozone backwashing decreased less than 10% for 4 hours filtration. This may be ascribed to the degradation of foulants in pore structure by the strong oxidation of ozone and physical exfoliation of cake layer on membrane surface with backwashing.

신뢰성 지수에 의한 위상최적화

임민규,박재용,황승민,오영규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

The objective of this work is to integrate reliability analysis into topology optimization problems. The reliability index determines design domain and uncertainty value. The elemental sensitivity numbers are calculated from finite element analysis and then converted to the nodal sensitivity numbers in the design domain. A mesh-independency filter using nodal variables is introduced to determine the addition of elements and eliminate unnecessary structural details below a certain length scale in the design. To further enhance the convergence of the optimization process, the accuracy of elemental sensitivity numbers is improved by its historical information. Application of the RBTO model gives a different topology relative to DTO. It is found that the RBTO model yields more reliable optimal topologies than those produced by DTO.

체적제어를 이용한 신뢰성 기반 위상 최적화

박재용,황승민,임민규,오영규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. Deterministic topology optimization (DTO) is obtained without considering of uncertainties related to the uncertainty parameters. However, the RBTO can consider the uncertainty variables because it has the probabilistic constraints. In this paper, the reliability index approach (RIA) is adopted to evaluate the probabilistic constraint. RBTO based on BESO starting from various design domains produces a similar optimal topology each other. Numerical examples are presented to compare the DTO with the RBTO.