유동장 자극이 화염의 질소산화물 배출에 미치는 영향

이기만 한국화재소방학회 2004 한국화재소방학회논문지 Vol.18 No.2

The effects of external flow excitation with various frequencies and amplitudes on the flame behavior and pollution emission characteristics from a laminar jet flame are experimentally investigated. Measurements of NOx emission indices (EINOx), performed in vertical lifted flame like turbulent with various exciting amplitude at a constant resonance frequency, have been conducted. It was also conducted to investigate the effects of excited frequency at a constant exciting amplitude on NOx emissions with a various frequency ranged 0 Hz to 2 kHz. From the vertical lifted turbulent flame of the excited jet with resonance frequency by strong excitation was shown that the dependence of NOx emission could be categorized into three groups : Group I of long flame length with high disturbances yielding high NOx emission, Group II of intermediate flame length and relative narrow flame volume with low disturbance yielding low NOx emission and Group III of long flame length and large flame volume with high time & space disturbances behaviour yielding high NOx emission. 층류 비예혼합 분류 화염에서 다양한 주파수와 강도로 외부에서 유동장에 자극을 주었을 때 화염의 배 출특성과 거동에 대해서 실험적으로 조사하였다. 먼저 일정한 관 공명 주파수에서 가진 강도를 가변시켜 난류화염 된 부상화염에서 질소산화물 배출 지수(EINOx)를 측정하였다. 또한, 가진 강도가 일정한 상태에 서 주파수를 0 Hz에서 높은 주파수인 2 kHz까지 다양한 주파수 조건으로 가진을 한 경우에도 질소산화물 의 배출지수를 측정하였다. 큰 가진 강도의 관공명 주파수로 가진된 경우 부상된 난류화염에서 NOx 배출 특성은 다음과 같이 크게 세 가지 형태의 특성을 보였다. Group I의 화염에서는 공간적인 섭동이 크며 비교적 화염길이가 길고 높은 NOx 배출 특성을 보였으며 Group II에서는 상대적으로 짧은 길이와 좁은 폭의 화염거동에 낮은 NOx 배출 특성을 보였다. Group III에서는 약간 긴 화염길이에 매우 큰 화염체적 으로 상당한 높이까지 시공간적으로 섭동이 큰 운동양태로 부상되는 거동과 가장 높은 NOx 배출 특성 을 보였다.

김선환박사의 공적을 칭송함

이기만 한국동물번식학회 1981 Reproductive & developmental biology Vol.5 No.2

탄소분산형 촉매에서의 암모니아를 이용한 질소 및 황 산화물 동시제거 특성

이기만,신동남,고동준,변영철,고경보,조무현,남궁원 한국공업화학회 2008 한국공업화학회 연구논문 초록집 Vol.2008 No.1

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.

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.

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 (+).

스마트팜과 노지에서 재배한 병풀의 생약학적 비교

이기만,박진홍,이다희,조성민,최정환,김남준,김민수,박영민 한국생약학회 2022 생약학회지 Vol.53 No.4

This study aimed to compare bioactivities of Centella asiatica (CA) cultivated in smart farms and fields. Component analysis, cell viability, anti-inflammatory activity, neuroprotection activity, and antioxidant activity were examined with 70% ethanol extracts of CA cultivated in smart farm (SEE) and field (FEE), respectively. Asiaticoside was analyzed by high performance liquid chromatography (HPLC) and as a result, SEE had more asiaticoside content than FEE. After treatment of RAW 264.7 cells with SEE and FEE, there was no cytotoxicity within the treated concentrations. SEE and FEE showed nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 inhibitory activities in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Moreover, SEE inhibited more NO, TNF-α, and IL-6 production levels than FEE. SEE and FEE reversed the H2O2-induced SH-SY5Y cell death. Especially, SEE was more effective in changing the H2O2-induced SH-SY5Y cell death than FEE. The antioxidant activity was confirmed by various methods such as total phenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide dismutase (SOD). As a result, SEE showed the most potent antioxidant activities about TPC, DPPH, and SOD methods. This study suggested that SEE has higher bioactivities such as effect of anti-inflammation, neuroprotection, and antioxidation than FEE.

예방 가능한 심정지 사망률 추정을 위한 기초연구

이기만,정성필,송근정,신준섭,김영택,김민정 대한응급의학회 2010 대한응급의학회지 Vol.21 No.6

Purpose: The wide range of survival rates after out-of-hospital cardiac arrest (OHCA) suggests that some deaths are preventable if an optimal emergency medical service (EMS)system is operated. The objective of this study was to propose a definition of preventable cardiac arrest death (PCAD) and to estimate the rate of PCAD in an area. Methods: This was a prospective cohort study of OHCA patients in the Gangnam-gu area of Korea. We collected data for OHCA patients from January to December 2009. PCAD was defined as an arrest case who is expected to survive if the patient received optimal first aid from bystanders and EMS personnel. A consensus panel of three emergency physicians determined whether each event was preventable or not. The survivability of each event was calculated using formulas from previous studies. Results: Among 104 arrests (an incidence of 18.3 per 100,000/year), 44 unexpected, non-traumatic arrests were analyzed. According to expert opinion, 16 of 30 (53%) who died within 24 hours after cardiac arrest were considered cases of PCAD. Survivability calculated using a previous formula was above 50% in 70% of patients. The Kappa value between the two estimations was only 0.247. Conclusion: The PCAD rate of Gangnam-gu area was estimated to be 53.3~70%. No bystander cardiopulmonary resuscitation, a delay in EMS activation, no use of an automated external defibrillator, or a delay in EMS arrival were considered problems in the process of pre-hospital care for sudden cardiac arrest.

마우스 모델에서의 생약복합제의 여드름 치료 효능

이기만,이금선,심홍,오세군,박일호,임동술,강태진 한국생약학회 2012 생약학회지 Vol.43 No.4

Acne, also known as Acne vulgaris, is a common disorder of human skin involving the sebaceous gland and Propionibacterium acnes (P. acnes). The purpose of this study was to demonstrate whether anti-acne herbal complex (AAHC), a functional extract from herbal complex can be used for acne treatment as a natural product. We first demonstrated anti-acne activity of AAHC in mouse acne model. Acne was induced by injecting P. acnes on the backside 2×10^7CFUs in ICR miceand then the mice were treated with AAHC by dermal application once daily. ACFREE®(clindamicin phosphate) was used as a positive control. Treatment with AAHC decreased the P. acnes-induced skin swelling and inflammation. AAHC treatment significantly decreased serum DHT concentration in acne-induced mice. Especially, treatment of 20% AACH in mice was more effected than 40%. We next evaluated the antimicrobial property of AAHC against P. acnes, Staphylcococcus aureus (S. aureus), and Escherichia coli (E. coli). Incubation of P. acnes, S. aureus, and E. coli with AAHC showed minimal inhibitory concentration (MIC) values against the bacterial growth lower. Alamar blue method was also carried for the antibacterial activity. It was effectively MIC level at 6.25% of P. acnes. AAHC effectively inhibited the growth of S. aureus and E. coli at 0.097%on MIC level, respectively. Our results showed the potential of using AAHC as an alternative treatment for antibiotic therapy of acne and the application of AAHC as a herbal medicine for acne treatment.

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.