• 대한기계학회논문집B
• /
• 제30권12호
• /
• pp.1188-1195
• /
• 2006

This paper examines the critical air temperature at which frost formation does not occur on a cold plate in order to improve the efficiency of a heat pump. The critical air temperature on test points is obtained from numerical analysis and a correlation of the critical air temperature is derived as a function of frosting factors (air absolute humidity, air velocity, and cold plate temperature) by least square method. Experiments are carried out to verify the correlation proposed in this study, and the prediction obtained with the correlation agrees well with the experimental data. Based on the correlation, we propose the non-frosting regions according to frosting factors.

• 한국자동차공학회논문집
• /
• 제5권2호
• /
• pp.173-182
• /
• 1997

The instantaneous flame temperature and soot formation and oxidation in a D. I. diesel engine are measured by using a two-color method. The proposed method based on the continuous spectral radiation from the soot particles in flames is applicable to industrial diesel engines without major modifications of their main characteristics. Measurements are performed at one location inside the combustion chamber of a D.I. diesel engine. Effects of different engine speeds and loads on flame temperature and KL factor which is an index of soot concentrations were examined. A little temperature change were observed with increasing engine speed, while increased with loads. The higher the flame temperature is, the lower the KL factor is.

• 한국버섯학회지
• /
• 제13권3호
• /
• pp.223-227
• /
• 2015

느타리버섯 '수한 1호'와 '곤지 7호'품종의 균사배양중 후배양 기간과 온도처리가 발이 균일도 및 생육에 미치는 영향을 조사한 결과는 다음과 같다. 배양중 전배양 $20^{\circ}C$, 20일 동안에는 두 품종 모두 11~15일에 $24{\sim}26^{\circ}C$까지 배지 내 온도가 상승되었다가 21일부터 후배양 온도처리와 동일한 수준으로 배지 내 온도가 유지되었다. 또한, 배지내 온도가 가장 높게 상승되는 시점에서 '수한 1호'의 $CO_2$는 6,500 ppm, '곤지 7호'는 5,800 ppm까지 발생되었으며 배양중인 균사생장에는 영향이 거의 없었다. '수한 1호'의 후배양 온도 $26^{\circ}C$에서 10일, 15일간 처리시 측발이율이 대조대비 40%, 비상품화율은 10.5% 감소 되었으며, '곤지 7호'는 후배양 온도 $26^{\circ}C$, 후배양 10일 처리에서만 측발이율은 19%, 비상품화율은 9.5% 감소되었다. 따라서, 느타리버섯 두 품종의 후배양 적합온도는 $26^{\circ}C$, 적합 후배양 처리기간은 '수한 1호'는 10일, 15일, '곤지 7호'는 10일이 발이 균일도가 높았다.

• Journal of Plant Biotechnology
• /
• 제30권1호
• /
• pp.41-45
• /
• 2003

Iris 속 식물인 꽃창포의 번식 특성에서 종자의 잡종성과 적은 분얼로 인한 분주 번식의 어려움을 해결하고 고유한 품종의 특성을 유지하기 위해서는 조직배양을 통한 대량 번식의 구명이 필요하므로 Iris 속 식물의 화기부위 별 절편체를 이용하여 기내 번식에 의한 대량 증식방법을 정립하고자 본 실험을 수행하였다. 자생꽃창포의 화피기부조직, 자방, 소화경, 화경을 치상하여 기내배양환경에 적절한 환경을 구명하고자 조도 2000 Lux에서 일장 (0~24시간), 온도 (10~3$0^{\circ}C$), sucrose (l~9%)의 조건에서 배양하였다. 자생꽃창포의 화기 절편체로부터 유식물체 재분화에 적합한 일장은 16시간의 장일조건이, 온도 조건은 $25^{\circ}C$에서, sucrose 농도는 3%에서 가장 적합한 것으로 나타났으며 특히 화기 부위 중 화피기부조직과 자방 배양에서 높은 신초 형성을 보였다. 화기조직 치상절편체로부터 부정근의 분화는 암상태에서 촉진되어지고 sucrose는 6%에서 뿌리를 생장시키며 1$0^{\circ}C$, 15$^{\circ}C$의 저온에서는 신초,뿌리의 분화가 저조하였다.

• 미생물학회지
• /
• 제6권4호
• /
• pp.113-121
• /
• 1968

This study has been aimed to determine the ecological factors with relationship to the Jongkok production in view of fermentation technology by means of some strains, Asp. kawachii, which is now preserved by the author and the following factors are included during the study; inorganic salts, nitrogen, sugar, water contents and temperature. The results, are as follows: (a) Sugar among other above-mentioned factors is increasingly affecting the number of the short type of conidiophore on culture medium and the conidiophore is increased by direct ratio until glucose concentration of 50%, at which concentration is mostly effective for the short type of conidiophore, while other factors did not affect on it. (b) Until glucose concentration of 50% sugar component of culture medium is favorable for the spore formation of Asp. kawachii by direct ratio. And peptone or asparagine on nitrogen medium, calcium-phosphate among other inorganic salts, wheat bran and rice branare also favorable, but other factors rientioned earlier show no relationship with the spore formation. Sugar, however, also related with the spore color clearness of crimson and light brown, and spore color is mostly clear at the point of glucose concentration until 50%. And asparagine on nitrogen medium, calcium phosphate among other inorganic salts, rice bran did all affect on the color clearness, while other factors did not concern with color clearness. (c) Water, sugar and temperature have related with the acid formation which is promoted, by direct ratio at the point of water-saturated condition and glucose concentration of 50%, while temperature at $25^{\circ}C$favorably affected on the acid formation which is increased by inverse ratio at the temperature$25^{\circ}C$ to $45^{\circ}C$ And pH did not relate with the acid formation. (d) Cylindrical plate method devised by the author is mostly favorable for the preservation and isolation of culture, compared with the traditional slant medium method.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
• /
• pp.339-342
• /
• 2014

Rotary kiln produces lime from limestone through thermal decomposition. Ring formation in kiln internal wall is known issue that decreases productivity. The cause of ring formation is temperature imbalance as flame leans toward upper wall. Therefore, burner nozzle geometry was changed to improve air-fuel mixing state which leads to prevention of ring formation. CFD simulation and experimental test were performed in this study to investigate the effect of air-fuel mixing on flame structure, temperature and $NO_X$ concentration. It is shown that combustion efficiency has been enhanced and $NO_X$ concentration has been decreased by using swirl flow for secondary combustion air. It's also shown that flame has been straightened by using straight flow for secondary combustion air.

• 전자공학회논문지A
• /
• 제28A권11호
• /
• pp.887-893
• /
• 1991

To take advantage of Ti-polycide, when it is contacted with both n+ and p+ active area of silicon, the effects of BF$_2$ on the formation of Ti-silicide were investigated with RTA temperature and dopant concentration. The intermediate phase C49 TiSi$_2$ appeared at $650^{\circ}C$ and the stable phase C54 TiSi2 was formed at $700^{\circ}C$. And the formation of Ti-silicide was hindered by BF$_2$ doping and this trend was decreased with increasing temperature. The out-diffusion phenomena of BF$_2$ into Ti silicide were not observed. And significantly, the native oxide was a chief factor preventing the formation of Ti-silicides.

• Ocean and Polar Research
• /
• 제26권3호
• /
• pp.515-521
• /
• 2004

The processes of formation and dissociation of gas hydrates were investigated by monitoring pressure and temperature variations in a pressure cell in order to understand the kinetic behavior of gas hydrate and the controlling factors fur the phase transition of gas hydrate below freezing. Gas hydrates were made kom guest gases ($CH_4,\;CO_2$, and their mixed-gas) and fine ice powder. We found that formation and dissociation speeds of gas hydrates were not controlled by temperature and pressure conditions alone. The results of this study suggested that pressure levels at the formation of mixed-gas hydrate determine the transient equilibrium pressure itself.

• 한국가시화정보학회:학술대회논문집
• /
• 한국가시화정보학회 2003년도 추계학술대회 논문집
• /
• pp.107-110
• /
• 2003

Characteristics of PAH and soot formation in coflow diffusion flames of methane, methane, propane, and ethylene have been experimentally studied to investigate the temperature and fuel structure effect on soot formation. PAH and soot images were acquired by applying PAH LIF and LII techniques, respectively and temperature was measured using R-type thermocouple. Direct photographs of soot particles have also been taken by transmission electron microscopy (TEM) through a thermophoretic sampling. Comparison of PAH and soot formation between the aliphatic fuels has shown the importance of fuel structure effect in diffusion flames.

• 전자공학회논문지A
• /
• 제28A권10호
• /
• pp.814-820
• /
• 1991

TaSi$_2$ was formed by rapid thermal annealing(RTA) on BF$_2$ doped single crystalline silicon substrates. The formation and various properties of TaSi$_2$ have been investigated by using 4-point probe, HP414, XRD, and SEM. And the redistribution of boron with RTA has been observed by SIMS. Implanted boron was diffused out into the TaSi$_2$ for RTA temperature but did not significantly affect the formation temperature of TaSi$_2$. Also, the contact resistance for TaSi$_2$/p$^{+}$ region had a low value 22$\Omega$, at contact size of 0.9$\mu$m, and the native oxide formed on Si-substrates by BF$_2$ implantation retarded the formation of TaSi$_2$.