주유동에 수직으로 분사되는 난류 비예혼합 분류 화염의 특성

이기만,박정,Lee, Kee-Man,Park, Jeong 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.1

An experimental study on the characteristics of stability of propane turbulent nonpremixed jet flames discharged normal to air free-streams with uniform velocity profile is conducted. Experimental observations are focused on the flame shape, the stability considering two kinds of flame, lift-off distance, and the flame length according to velocity ratio. In order to investigate the mixing structure of the flame base at the lower limit, we employ the RMS technique and measure the species concentration by a gas chromatography. In the results of the stability curve and lifted flame, it is fecund that the dependency of nozzle diameter is closely related to the large-scale vortical structure representing counter-rotating vortices pair. Also, the detailed discussion on the phenomenon of blowout due to this large vortical motion, is provided.

곤충병원성진균의 총 페놀 함량 및 DPPH 라디칼 소거능

이기만,남성희,송하석,여주홍,이광길,배윤환,Lee, Ki-Man,Nam, Sung-Hee,Song, Ha-Suk,Yeo, Joo-Hong,Lee, Kwang-Gill,Bae, Yoon-Hwan 한국응용곤충학회 2009 한국응용곤충학회지 Vol.48 No.3

곤충병원성진균 20종의 총 페놀 함량, 항산화활성 및 항균활성간의 관계를 조사하기 위해 본 실험을 수행하였다. 총 페놀 함량은 Aspergillus flavus에서 $553.0{\pm}52.15{\mu}g/g$, A. parasiticus에서 $529.9{\pm}60.10{\mu}g/g$으로 가장 높게 나타났으며, 다른 균주는 $26.6{\sim}121.9{\mu}g/g$으로 나타났다. DPPH(1, 1-diphenyl-2-picrylhydrazyl) radical 소거능은 대부분의 균주에서 나타났으며 다른 균주에 비하여 A. flavus와 A. parasiticus에서는 각각 $90.9{\pm}2.90%$와 $77.9{\pm}4.13%$로 높게 나타나 항산화활성과 총 페놀 함량 간 높은 연관성이 나타났다. 항균활성은 모든 식중독균에 대하여 나타났으며 Listeria monocytogenes와 Escherchia coli에 대하여 특히 강하였다. This study was conducted to investigate the total phenol contents, antioxidative activities and antibacterial activities of twenty species of entomopathogenic fungi. The total phenol content was highest in Aspergillus flavus ($553.0{\pm}52.15{\mu}g/g$) and A. parasiticus ($529.9{\pm}60.10{\mu}g/g$). On the other hand those in other strains were within the range of $26.6{\sim}121.9{\mu}g/g$. The antioxdative activity was shown in the most of strains and the highest DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging activity was observed in A. flavus ($90.9{\pm}2.90%$) and A. parasiticus ($77.9{\pm}4.13%$). This result indicated that the antioxidative activities were very correlated with the total phenol contents. The antibacterial activitiy was found in the every tested pathogenic bacteria. Especially, the antibacterial activity was strongest against Listeria monocytogenes and Escherchia coli.

횡분류(流)(橫噴流)에서 난류 비예흔합 화염의 화염날림에 대한 거대 와(渦)구조 혼합 모텔 적용

이기만,박정,Lee, Kee-Man,Park, Jeong 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.1

This article presents an application of a large-scale structural mixing model(Broadwell et at. 1984) to the blowout of turbulent reacting cross flow jets. Experimental observations, therefore, aim to identify the existence of large-scale vortical structure exerting an important effect upon the flame stabilization. In the analysis of common stability curve, it is seen that the phenomenon of blowout are only related to the mixing time scale of the two flows. The most notable observation is that the blowout distance is traced at a fixed positions according to the velocity ratio at all times. Measurements of the lower blowout limits in the liftable flame are qualitatively in agreement with the blowout parameter $\xi$, proposed by Broadwell et al. Good agrement between the results calculated by a modified blowout parameter $\xi$'and the present experimental results confirms the important effect of large-scale structure in the stabilization feature of blowout.

음향 가진된 층류 비예혼합 분류 화염에서 거대 와류 거동에 관한 가시화 연구

이기만,오세기,박정,Lee, Kee-Man,Oh, Sai-Kee,Park, Jeong 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.3

A visualization study on the effect of forcing amplitude in tone-excited jet diffusion flames has been conducted. Visualization techniques are employed using optical schemes. which are a light scattering photography. Flame stability curve is attained according to Reynolds number and forcing amplitude at a fuel tube resonant frequency. Flame behavior is globally grouped into two from attached flame to blown-out flame according to forcing amplitude: one sticks the tradition flame behavior which has been observed in general jet diffusion flames and the other shows a variety of flame modes such as the flame of a feeble forcing amplitude where traditionally well-organized vortex motion evolves, a fat flame. an elongated flame. and an in-burning flame. Particular attention is focused on an elongation flame. which is associated with a turnabout phenomenon of vortex motion and on a reversal of the direction of vortex roll-up. It is found that the flame length with forcing amplitude is the direct outcome of the evolution process of the formed inner flow structure. Especially the negative part of the acoustic cycle under the influence of a strong negative pressure gradient causes the shapes of the fuel stem and fuel branch part and even the direction of vortex roll-up to dramatically change.

백강균의 분생자병속 형성 조건

이기만,남성희,윤철식,전지영,여주홍,이광길,Lee, Ki-Man,Nam, Sung-Hee,Yoon, Cheol-Sik,Jeon, Ji-Young,Yeo, Joo-Hong,Lee, Kwang-Gill 한국응용곤충학회 2010 한국응용곤충학회지 Vol.49 No.1

백강균(Beauveria bassiana)의 분생자병속 형성 조건 구명을 위해 본 실험을 수행하였다. 균은 제주도 설악산 일대에서 치사한 참매미로부터 분리되었다. 분생자병속 형성 유도 배지는 현미와 누에번데기를 원료로 하여 90:10 비율로 조제한 경우가 가장 효과적이었으며, 기타 배지 상에서는 분생자병속 발생이 관찰되지 않았다. 분생자병속은 공기 유입량이 최소일 때 형성이 효과적이었으며, 분생자병속 발생의 최적 온도는 $20^{\circ}C$, 배지 수분함량은 60% 및 조도 300 lux이었다. 또한, 증식에 활용한 종균은 액체배양균이 무성포자보다 분생자병속 형성에 더욱 효과적이었다. This study was conducted to investigate optimal conditions for formation of synnemata from Beauveria bassiana. The strain of B. bassiana was isolated from a host of Oncotympana fuscata in Halla mountain of Jeju island. The yield of synnemata was the highest at application of brown rice (90%) and silkworm pupae (10%) media. On the other hand, the other media did not result in formation of synnemata. The highest formation of synnemata was achieved at conditions of moderate air inflow and $20^{\circ}C$. The optimal moisture and light intensity for formation of synnemata were 60% and 300 lux, respectively. In addition, inoculation of the liquid spawn resulted in higher yield than that of asexual spore.

노린재동충하초의 배양 최적화 및 NO 생성 저해 효과

이기만,이금선,남성희,임성실,강태진,Lee, Ki-Man,Lee, Geum-Seon,Nam, Sung-Hee,Lim, Sung-Cil,Kang, Tae-Jin 한국응용곤충학회 2011 한국응용곤충학회지 Vol.50 No.4

동충하초는 예로부터 아시아권에서 한방약재로 사용되어 온 곤충병원성진균이다. 이 중 노린재동충하초(Cordyceps nutans)는 자연 상태에서 비교적 많이 발견되나 이에 대한 연구가 미미한 편이다. 따라서 본 실험에서는 C. nutans 균사체의 최적 배양 조건을 확립하고 배양액 처치 시대식세포의 NO (nitric oxide) 생성 억제 효능을 조사하였다. 균사 생육 적정 온도는 $25^{\circ}C$이었으며 pH는 7.0~8.0 사이의 중성범위로 조사되었다. MCM (mushroom complete medium), V8A (V8 juice agar), YMD (yeast malt dextrose) 배지에서는 균사 생육이 우수하였으나 MMM (mushroom minimal medium) 배지의 경우 균사 생육이 이루어지지 않아 영양원이 필수적이었다. 영양원 선발에 있어 탄소원은 dextrose와 sucrose가 적합하였고 질소원은 ammonium citrate가 균사 생장에 적합하였다. RAW 264.7 세포에 대한 C. nutans 배양액의 세포 독성은 나타나지 않았으며 LPS (lipopolysaccharide)를 처리 한 세포의 NO 생성량은 농도 의존적으로 줄어들었다. 따라서 본 실험 결과는 C. nutans 배양 시 다량의 균사체를 확보할 수 있는 최적 조건을 제공할 뿐 아니라 C. nutans의 항염 관련 우수한 생리 활성이 있음을 보여준다. Cordyceps (vegetable wasp and plant worm), an entomopathogenic fungi, has been used as a herbal medicine in Asian countries since ancient times. Cordyceps nutans is common but there is little research on this species. This study investigated the optimal culture conditions of C. nutans and the inhibitory effect on nitric oxide (NO) production in RAW 264.7 cell treated culture broth. The optimal conditions for the mycelial growth were $25^{\circ}C$ and pH 7.0-8.0. Mycelial growth was highest on mushroom complete medium (MCM), V8 juice agar (V8A), and yeast malt dextrose (YMD) medium. Mycelial growth on mushroom minimal medium (MMM) did not occur, so nutrient source was essential. Dextrose and sucrose as carbon sources, and ammonium citrate as a nitrogen source were satisfactory for mycelial growth. Cytotoxicity of C. nutans culture broth was not found in RAW 264.7 cells. C. nutans culture broth suppressed NO production of lipopolysaccharide (LPS)-stimulated RAW 264.7 cell in a dose-dependent manner. Thus, our results provided the optimal conditions for cultivation of C. nutans and showed that C. nutans may have excellent physiological activities.

수소/이산화탄소/알곤 혼합 연료의 비예혼합 대향류 화염에서 NO 배출 특성 연구

이기만,Lee, Kee-Man 한국자동차공학회 2007 한국 자동차공학회논문집 Vol.15 No.4

The detailed chemistry with reaction mechanism of GRI 2.11, which consists of 49 species and 279 elementary reactions, have been numerically conducted to investigate the flame structure and NO emission characteristics in a non-premixed counterflow flame of blended fuel of $H_2/CO_2/Ar$. The combination of $H_2,\;CO_2$, and Ar as fuel is selected to clearly display the contribution of hydrocarbon products to flame structure and NO emission characteristics due to the breakdown of $CO_2$. Radiative heat loss term is involved to correctly describe the flame dynamics especially at low strain rates. All mechanisms including thermal, $NO_2,\;N_2O$, and Fenimore are also taken into account to separately evaluate the effects of $CO_2$ addition on NO emission characteristics. The increase of added $CO_2$ quantity causes flame temperature to fall since at high strain rates diluent effect is prevailing and at low strain rates the breakdown of $CO_2$ produces relatively populous hydrocarbon products and thus the existence of hydrocarbon products inhibits chain branching. It is also found that the ratio of the contribution by Fenimore mechanism to that by thermal mechanism in the total mole production rate becomes much larger with increase in the $CO_2$ quantity and strain rate, even though the absolute quantity of NO production is deceased. Consequently, as strain rate and $CO_2$ quantity increase, NO production by Fenimore mechanism is remarkably augmented.

돈의 혈정단백질에 관한 연구

이기만,한상기,정의용 ( Khi M . Lee,Sang K . Han,Eui Y . Chung ) 한국축산학회 1984 한국축산학회지 Vol.26 No.4

The phenotypes, genotypes and its gene frequency in genetic variant of Transferrin (Tf) and Pre-albumin (Pa) in serum proteins from total 134 individual pigs, Large White (LW), Duroc (D), Berkshire (B), Landrare (L) and Crossbred (C.B), reared in Korea were investigated by means of starch gel electrophoresis and their gene frequencies and genetic similarities were compared with those of foreign Pig breeds. The results are summarized as follows: 1. Tf and Pa of serum protein in pigs were controlled by co-dominant autosomal allelic gene of TF^A and Tf^B, and Pa^A and Pa^B, respectively. 2. In the phenotypes of Tf of LW, B, L and C.B breeds, Tf AB and Tf BB genetic variants were observed. In the D breed only Tf BB variant was found and the Tf AA homozygous was not observed in all breeds. In the phenotypes of Pa, genetic variants of Pa AA, Pa AB and Pa BB were commonly observed in all breeds. However, one pig of Tf AB heterozygous was appeared in the L breed. It was supposed to crossbred pig because of including A gene. Therefore, it was considered that the purity of a boar and a breed sow in Korea was in need of reexamination. Distribution of the phenotypes of serum protein loci in all the breeds with the exception of C.B breed agrees with Hardy - Weinberg equilibrium. 3. The gene frequencies of Tf B in LW, B, L, D and C.B breeds were 0.714, 0.833, 0.917, 1.000 and 0.160, respectively. In the Pa the LW, D and B breeds showed high gene frequency of the Pa^A variant with 0.571, 0.625 and 0.667, but Pa^B variant showed low gene frequency with 0.429, 0.375 and 0.333, respectively. However, Pa^B with a frequency of 0.583 was slightly higher than that of Pa^A (0.417) in the L breed. Frequencies of 0.571, 0.625 and 0.667 for the LW, D and B breeds showed high gene frequency of the Pa^A, whereas Pa^B showed low gene frequency (0.429, 0.375 and 0.333, respectively). The Pa^B with 0.604 gene frequency in C.B breed was also high, but Pa^A was in low gene frequency of 0.396.

번데기동충하초와 눈꽃동충하초의 배양특성 및 항균활성

이기만,홍인표,남성희,성규병,배윤환,Lee, Ki-Man,Hong, In-Pyo,Nam, Sung-Hee,Sung, Gyoo-Byung,Bae, Yoon-Hwan 한국응용곤충학회 2008 한국응용곤충학회지 Vol.47 No.4

Cordyceps militaris(번데기동충하초)와 Paecilomyces tenuipes(눈꽃동충하초)의 배양특성 및 항균활성을 비교하였다. 균사 생장 최적 배지는 C. militaris는 MCM, P. tenuipes는 YMA이며 MMM 배지 상에서는 두 균주 모두 생장이 저조하였다. 균사 생육 최적 온도는 $25^{\circ}C$이였고 C. militaris는 5회 이상 계대 시 균사 생육이 저하되었다. 적정 영양원 선발에 있어 두 균주 모두 탄소원은 단당류의 fructose, 이당류의 maltose 그리고 다당류의 dextrin이 적합하였다. 질소원은 유기태에서 C. militaris는 calcium nitrate, P. tenuipes는 sodium nitrate가 적합하였으며 무기태에서는 ammonium tartrate가 적합하였다. 항균활성은 Gram(+)의 Bacillus cereus에 대하여 C. militaris에서만 나타났다. The cultural characteristics and antibacterial activities of Cordyceps militaris and Paecilomyces tenuipes were compared. The mycelial growth was the highest on MCM (Mushroom Complete Medium) for C. militaris and on YMA (Yeast Malt Agar) for P. tenuipes. But the mycelial density on MMM (Mushroom Minimal Medium) was lower than other on media. The optimum mycelial growth was observed at $25^{\circ}C$. C. militaris was low mycelial growth when it was transferred over 5 times generation. The carbon source for the optimum mycelial growth was fructose of monosaccharide, maltose of disaccharide and dextrin of polysaccharide. The calcium nitrate of organonitrogen was found the best mycelial growth on C. militaris, while the sodium nitrate observed to be well for mycelial growth on P. tenuipes. The ammonium tartrate was observed to be the best among the inorganonitrogen used for mycelial growth. Antibacterial activities were found out just C. militaris against Bacillus cereus of Gram (+).

수소-산소 대향류 확산 화염에서 산화제와 연료측에 첨가된 Co₂의 화학적 효과에 관한 수치해석 연구

이기만,박정,Lee, Kee-Man,Park, Jeong 대한기계학회 2004 大韓機械學會論文集B Vol.28 No.4

Numerical simulation of $CO_2$ addition effects to fuel and oxidizer streams on flame structure has been conducted with detailed chemistry in H$_2$-O$_2$ diffusion flames of a counterflow configuration. An artificial species, which displaces added $CO_2$ in the fuel- and oxidizer-sides and has the same thermochemical, transport, and radiation properties to that of added $CO_2$, is introduced to extract pure chemical effects in flame structure. Chemical effects due to thermal dissociation of added $CO_2$ causes the reduction flame temperature in addition to some thermal effects. The reason why flame temperature due to chemical effects is larger in cases of $CO_2$ addition to oxidizer stream is well explained though a defined characteristic strain rate. The produced CO is responsible for the reaction, $CO_2$+H=CO+OH and takes its origin from chemical effects due to thermal dissociation. It is also found that the behavior of produced CO mole fraction is closely related to added $CO_2$ mole fraction, maximum H mole fraction and its position, and maximum flame temperature and its position.