• The Journal of Engineering Geology
• /
• v.23 no.4
• /
• pp.435-445
• /
• 2013

Since design response spectrum does not reflect local soil characteristics, site specific response spectrum of observed ground motions appears relatively higher than design response spectrum at high frequency range. These problems have been pointed out from the domestic seismic design industry. Among various estimation methods, this study used the method H/V ratio of ground motion for estimating site amplification. This method has been extended to background noise, Coda waves and S waves recently for estimating site amplification. This study applied this method to the background noise and Coda wave energy. This study analysed more than 267 background noises from 15 macro earthquakes including main Fukuoka earthquake (2005/03/20, M=6.5) and then compared to results from S waves, at 8 main domestic seismic stations. The results showed that most of the domestic seismic stations gave similar results to those from S waves. Each station showed its own characteristics of site amplification property in low, high and specific resonance frequency ranges. Comparison of this study to other studies using different method can give us much information about dynamic amplification of domestic sites characteristics and site classification.

• Journal of agriculture & life science
• /
• v.45 no.4
• /
• pp.135-141
• /
• 2011

This research was conducted to provide basic data of surplus heat for designing solar heat-storage systems. The surplus heat is defined as the heat exhausted by forced ventilations from the greenhouses to control the greenhouse temperature within setting limits. Various simulations were performed to compare the differences of thermal behaviors among greenhouse types as well as among several domestic areas by using pseudo-TMY (Typical Meteorological Year) data manipulated based both on the weather data supplied from Korean Meteorological Administration and the TMY data supplied from The Korean Solar Energy Society. Additional analyses were carried out to examine the required heating energy together with some others such as the energy balances in greenhouses to be considered. The results of those researches are summarized as follows. Regional surplus solar heats for the nine regions with 4-type were analyzed. The results showed that the ratio of surplus solar energy compared to heating energy was the highest in Jeju (about 212.0~228.0%) for each greenhouse type. And followed by Busan, Kwangju, Jinju, Daegu, Daejeon, Jeonju, Suwon and Daekwanryung. And irrespective of greenhouse types, surplus solar energy alone could cover up nearly all of the required supplemental heating energy except for a few areas.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.4
• /
• pp.381-386
• /
• 2015

Environmental pollution and alternative energy has attracted increasing interest. The use of diesel engines is expected to increase in the world owing to their fuel economy. The problem of air pollution emissions from marine engines is causing a major concern in many areas. An alternative fuel was introduced as an environmentally friendly fuel to reduce the toxic emissions from conventional fossil fuels. Biodiesel fuel, which is a renewable energy is highlighted as environmentally friendly energy. This energy can be operated in regular diesel engines when it is blended with invariable ratios without making changes. In this study, a bio-diesel fuel was produced from waste cooking oil and applied to a marine diesel engine to examine the effects on the characteristics of combustion. Waste cooking oil contains a high cetane number and viscosity component, a low carbon and oxygen content. As a result, the brake specific fuel consumption was increased, and the cylinder pressure, rate pressure rise and rate of heat release were decreased.

• Korean Journal of Poultry Science
• /
• v.18 no.2
• /
• pp.85-95
• /
• 1991

The investigation concerned an effect of the ground charcoal powder and organic acids on the digestibilities of protein and energy or the contents of uric acid, ammonia, creatine and urea in excreta of 113 week-old White Leghorn strain layers. Birds were fed basal (control) diet composed of mainly corn-soybean meal during a week of previous feeding and subsequent experimental diets during 12 weeks of experimental feeding . The experimental diets were the control diet(CON). diet(CPD) substituted 0.5% of the ground charcoal powder with the defatted rice bran of the CON, diet(PWV) added 0.1mM(based on the acetic acid) wood vinegar in the CPD and diet(PFA) added 0.1mM (based on the acetic acid) fermented acetic acid in the CPD. Birds fed CPD excreted significantly(P＜0.05) more fecal nitrogen(FN) and lower urinary nitrogen (UN) than those of birds fed CON. Digestibility of protein was lower significantly (P＜ 0.05) in CPB-fed bird than in bird fed CON. while birds fed CON. PWV and PFA showed similar values. Also urinary nitrogen per nitrogen intake (UN/NI) or absorbed nitrogen (UN/AN) was significantly (P＜0.05) lower in birds fed CPD compared with those in birds fed CON. And birds fed PWV tended to increase UN/NI and UN/AN, while PFA-fed birds excreted significantly (P＜0.05) higher UN/Nl and UN/Ah than those of birds fed CPD diet. The uric acid nitrogen (UAN) per nitrogen intake (UAN/NI) or absorbed nitrogen (UAN/AN) were lower significantly(P＜0.05) in CPD-fed birds and were tended to decrease in birds fed PWV compared with those in birds fed CON and PFA The ammoniacal nitrogen(AMN) per nitrogen intake (AMN/NI) or absorbed nitrogen (AMN/NI) was tended to increase in birds fed experimental diets and was increased significantly(P＜0.05) in birds fed PFA compared with those of birds fed CON. The excretion of creatine and urea nitrogen per nitrogen intake or absorbed nitrogen was shown similar values among birds fed experimental diets Digestibility of energy (DE/GE) was not shown any significant effect of experimental diet and were in the range of 80~84%. But metabolizability (ME/GE or MEn/GE) was increased in birds fed CPD and PWV and was decreased in birds fed PFA compared with those in birds fed CON. Although birds fed PWV showed significantly(P＜0.05) higher ME/GE than bird fed PFA, the MEn/GE were higher significantly (P＜0.05) in birds fed CON and CPD compared with that in birds fed PFA. Fecal energy affects 10~23% in the change of metabolizability though significant effect of fecal energy on the metabolizability were not found. But the effect of urinary energy on the metabolizability of diet was lowered as 2.3~3, 0% and the effect of experimental diets on the metabolizability of diets was due to change of urinary energy which also was originated from the change of uric acid energy.

• Transactions of the KSME C: Technology and Education
• /
• v.3 no.4
• /
• pp.285-290
• /
• 2015

Oxy gasification was performed for the production of high quality syngas from the waste. $CO_2$ was used as reactant with $O_2$ for $CO_2$ gasification and greenhouse gas reduction. Therefore, gasification was performed at high temperature of $1000-1400^{\circ}C$. RPF was gasified in the thermobalance and 0.5 ton/day pilot plant gasifier. Weight variation with temperature and CO production by Boudouard reaction were studied for $CO_2$ gasification of RPF in thermobalance reactor. Syngas of high $H_2$ concentration was produced from oxy gasification in 0.5 ton/day pilot system, which showed appropriate $H_2$/CO ratio for the production of transport fuel and chemical products.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.4
• /
• pp.373-378
• /
• 2011

The freeze desalination cycle with seawater heat pump system is simulated and designed for the basic data for the design of freeze desalination system. The basic model of seawater heat pump system is refrigeration cycle and indirect freeze desalination method is used for seawater desalination. The cycle performance of seawater heat pump such as COP, compressor work, condensing capacity was analyzed and the desalination performance such as fresh water productivity and energy per unit fresh water productivity was compared with respect to the seawater temperature of condenser inlet and ice ratio in the evaporator. The compressor work and condensing capacity decreased with respect to the decrease of seawater inlet temperature. The energy per unit fresh water productivity in case of $8^{\circ}C$ seawater inlet temperature showed 28.9% lower than that of $20^{\circ}C$.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.2 no.6
• /
• pp.50-56
• /
• 1994

This is an experimental study on the performance characteristics of Diesel Automobile with ultrasonic fuel feeding system. For this purpose, ultrasonic fuel feeding system was made and atomization characteristics was measured. Base on this result, carried out engine dynamometer test to investigate the performance characteristics of diesel automobile with ultrasonic fuel feeding system in comparison with conventional diesel fuel injector. The results are as follows. 1) In the spray characteristics test, fuel particle sizes were decreased about 11%~21%. 2) In engine dynamometer test, -The power was increased about 5%~11%. -The thermal efficiency was improved about 6%~11%. -The specific fuel consumption was improved about 6%~19%. -The smoke concentration was decreased about 11%~50%.

• Transactions of the Korean hydrogen and new energy society
• /
• v.28 no.1
• /
• pp.92-97
• /
• 2017

Kerosene (Coal oil) is a particularly attractive fuel because it is widely used to power jet engines of aircraft as jet fuel and some rocket engine. This paper describes the performance and emission characteristics according to the collant temperature of combustion chamber head of spark ignition engine fuelled with kerosene. As a result, the following knowledge is obtained. As the collant temperature of combustion chamber head is decreased, torque, volumetric efficiency and brake specific fuel consumption have been increased. When coolant temperature of combustion chamber lower, THC emission increased but CO and $NO_x$ emission decreased.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.4
• /
• pp.32-37
• /
• 2011

Biodiesel fuel is already remarkable alternative fuel in many countries. So, many studies are performed on the environmental or economic effects as well as the characteristics of diesel engine fueled biodiesel in combustion and emission. In this study, an CRDI diesel engine used to commercial vehicle was fueled with diesel fuel and 20% biodiesel blended fuel (BDF 20%) with city mode in excess of 300 hours. Engine dynamometer testing was completed at regularly scheduled intervals to monitor the engine performance and exhaust emissions. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. To check the engine parts (valve and injector), the engine was inspected after test. It was concluded that there were no unusual deteriorations of the engine, or any unusual changes in engine power and exhaust emissions in spite of operation of 300 hours with BDF 20%.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.11a
• /
• pp.525-528
• /
• 2006

아임계 및 초임계수에 의한 목질바이오매스의 당화특성을 분석하기 위하여 분해공정 동안 압력을 23MPa(물의 임계압력)로 고정하고 물의 아임계 온도$(325^{\circ}C,\;350^{\circ}C)$와 초임계 온도$(380^{\circ}C,\;400^{\circ}C,\;425^{\circ}C)$에서 현사시나무 목분을 각각 60초 동안 처리하였다. 생성된 현사시나무의 분해산물에는 액상과 고형분의 분해산물이 섞여 있었다. 각 처리조건에 따른 목질바이오매스의 분해율은 온도가 상승함에 따라 증가하였으며 초임계 온도인 $425^{\circ}C$에서 최고 83.1%의 분해율을 나타냈다. 아임계 및 초임계수에 의해서 생성된 단당류는 고성능 음이온 교환 크로바토그래프(HPAEC)를 이용하여 분석하였다. 목질바이오매스의 초임계수 분해과정에서 처리 온도가 높아지면서 단당류 수율은 증가하는 경향을 보였으며, $425^{\circ}C$에서 가장 높은 7.3%의 단당류 수율을 나타내었다. 아임계 온도 범위에서는 현사시나무의 섬유소 성분 중에서 자일란이 우선적으로 분해되어 자일로스의 생성비율이 비교적 높았으며, 처리온도가 높아지면서 셀롤로오스의 분해에 의한 글루코오스 생성율이 급격히 상승하였다. 이렇게 생성된 단당류 성분들은 고온의 반응조건하에서 열분해 반응에 의해서 더욱 분해되어 퓨란계 화합물로 변형되었다.