본 연구에서는 운전자의 피로감을 경감시킬 수 있는 자동차용 향 분사 시스템을 개발하였다. 또한 향 분사시스템의 운전자 적응 특성을 분석하였다. 향 분사 시스템은 휘발된 향을 산소 (공기)와 혼합시켜 외부로 분사하는 방식을 이용하였다. 8051 마이크로프로세서를 이용하여 2-Port Solenoid Valve의 on/off 시간을 변경 가능하도록 하였고 이를 통해 향 분사량을 제어할 수 있도록 하였다. 평균나이 22±2세인 남녀 대학생 20명을 대상으로 네 가지 천연 향 (쟈스민 30%, 쟈스민 50%, 페파민트 30%, 페파민트 50%)을 사용하여 향의 적응화가 발생하는 시간과 향에 대한 적응화가 제거되는 시간을 결정하는 실험을 수행하였다. 실험 결과 쟈스민 30% 향의 적응화 발생시간은 1분 28초, 적응화 제거시간은 3분 15초, 쟈스민 50% 향의 적응화 발생시간은 2분 41초, 적응화 제거시간은 4분 3초, 페파민트 30% 향의 적응화 발생시간은 1분 47초, 적응화 제거시간은 2분 59초, 페파민트 50% 향의 적응화 발생시간은 1분 58초, 적응화 제거시간은 4분 11초였다.

Water jet trajectories and velocity deficits from a high pressurize nozzles were experimentally observed. In this article, several parameters affecting plugging and erosion onto the steam generator tube were quantitatively analyzed. Visualization, velocity distribution, and spray growth rate with different nozzle configurations have been mainly focused using a 2-D PDPA (Phase Doppler Particle Analyzer) system. The results indicated that trajectories along the centerline regardless of their momentum has its potential core region. However, the phenomena from the peripheral part need to be meticulosly considered. Accordingly, it is evident that quantitative velocity deficits at the outer region are outstanding due to the aerodynamical drag and entrainment.

To comparison the surface treatment methods of stone board materials, the results of Dorry's abrasive test were 23.4 for water-jet system and 18.9 for flame-burner system. Therefore abrasive hardness, the stone board materials by the water-jet system was greater than one by flame-jet system. As a result of Shore's hardness test, the stone board materials by water-jet system was twice greater than one by flame-jet system. Authors carried out microscopic observation to survey a defection of the composition minerals for two methods, but all of the both methods have not founded a defection. Therefore, the stone board materials by water-jet system was greater durability than one by flame-jet for the surface treatment methods.

Al-l4wt.%Ni-l4wt.% Mm(Mm=misch metal) alloy powders rapidly solidified by the gas atomization method were subjected to mechanical milling(MM). The morphology, microstructure and hardness of the powders were investigated as a function of milling time using scanning electron microscopy(SEM), transmission electron microscopy(TEM) and Vickers microhardness tester. Microstructural evolution in gas-atomized Al-l4wt.%Ni-l4wt.% Mm(Mm=misch metal) alloy powders was studied during mechanical milling. It was noted that the as-solidified particle size of decreases during the first 48 hours and then increases up to 72 hours of milling due to cold bonding and subsequently there was continuous refinement to on milling to 200 hours. Two microstructurally different zones, Zone A, which is fine microstructure area and Zone B, which has the structure of the as-solidified powder, were observed. The average thickness of the Zone A layer increased from about 10 to in the powder milled for 24 hours. Increasing the milling time to 72 hours resulted in the formation of a thicker and more uniform Zone A layer, whose thickness increased to about . The TEM micrograph of ball milled powder for 200 hours shows formation of nano-particles, less than 20 nm in size, embedded in an Al matrix.

The contamination problem is getting worse now a day because of the industrial activities. Recently it has been announced that there's environmental hormone in river and lake which produces clean water, also there's too many of algae reproduces under the water and some virus in the drinking water. The quality of water is very important. pure and clean water is not only a precondition for human being to live but a basic factor to improve the quality of life. so a water purification system must be developed. This study is about the surface washing treatment technique. We tried to use a rotary nozzle to get a tush degree of efficiency, for it was not enough with present way of washing. The nozzle is run by water pressure. The results of the experiment are as follows. We got a clean and equal surface after washing. After washing, the water's maximum consistency was 330NTU and it shows that this way is better than before one with 215NTU. Clean level of the filter was 6˚and it's 2.8 times higher than 17˚with the old way. We can see the results that the new way of washing is more effective than old way based on this study.

An experimental study of the fire protection performance of water mist spray subjected to thermal radiation was presented. Downward-directed water mist sprays to interact with an under. gasoline pool fire were experimentally investigated in underground environment. The mass mean diameters of water mist droplet were measured by PMAS under various flow conditions. The developed water mist spray nozzle was satisfied to the criteria of NFPA 750. The mechanism of the fire extinguishment by water mist spray was concluded to be cooling of the fire surface which lead to suppressed of' file1 evaporation. It was proved that the water mist spray system under. lower pressures could be applied to underground fire protection system.

In order to investigate the effectiveness of methanol, which has high latent heat of evaporation and oxygen contents, for DI diesel engine performance and exhaust emission, the methanol was injected at the suction port of DI diesel engine. The injector used for test was conventional gasoline engine injector and controlled the quantity of methanol per cycle by the power supply controller which designed specially for injector. The results shown that the maximum pressure point was delayed, the value of maximum pressure was decreased, and the concentrations of both NOx and Soot were decreased, as the methanol injection quantity increased, and also the thermal efficiency of engine injected methanol under the high load condition was similar to no methanol injection but under the medium load condition was decreased within the experimental conditions.

육묘장의 두상관수장치는 균일하게 관수되어야 모종도 균일하게 성장한다. 본 연구에서는 부채꼴 분사노즐을 이용한 두상관수장치의 노즐 설치위치에 따른 관수상태를 조사하여 균일관수방법을 구명하였다. 살수량은 주행속도에 반비례하였고, 관수균일도는 노즐과 관수면과의 거리에 큰 영향을 받으며 주행속도의 영향은 없었다. 단일노즐에 의한 두상관수인 경우 노즐 끝에서 관수면이 60cm 이상 멀어질수록 관수균일도가 향상되며, 연속노즐에 의한 두상관수인 경우 관수면이 노즐분사 각도의 2차 교차점에 위치할 때 관수균일도가 가장 좋은 것으로 나타났다. 두상관수장치의 균일관수를 위해서는 작물의 머리높이가 분사노즐의 2차교차점에 일치하도록 노즐의 위치를 정해야 하며 작물의 자람에 따른 노즐대 놀이를 조절해 주는 것이 바람직한 것으로 판단된다.

현재까지 박막코팅 분야에 주로 이용해 오던 플라즈마 용융분사법을 이용하여 고밀도의 두꺼운 세라믹 침적물을 제조하였다. 용융점이 2910K인 ZrO2-20wt%Y2O3분말을 이용하여 최적조건에서 이론밀도의 약 97%의 침적물을 얻었다. 고밀도 침적에 영향을 미치는 변수는 챔버 내부압력, 플라즈마동력, 플라즈마 가스조성, 분사거리, 분말입자 크기 등이었으며, 침적밀도 및 침적된 splat의 형태는 분말의 용융정도 및 챔버 내부압력에 크게 좌우되었다. 높은 밀도으 침적물을 만들기 위해서는 분말을 완전히 용융시키는 것이 중요하며, 완전히 용융된 조건에서는 챔버 내부압력이 낮고 분말분사거리가 짧은 조건 즉, 분사되는 분말이 높은 모멘텀을 가질수록 침적물의 밀도가 증가함을 알 수 있었다. 실험에서 얻어진 결과는 ANOVA 통계방법으로 분석하여 단일변수의 영향뿐만 아니라 이들 변수가 서로 조합하여 밀도에 미치는 영향도 분석하였다.

Atomizing mode and powder characteristics of CuA1Ni base shape memory alloy in rotating disk atomization were investigated in accordance with disk materials and additional elements. Produced powders were classified into two types of spherical and flake shape. In the case of CuAlNiBTi and CuAlNiZr alloy, high yield rate and fine powder were obtained. This tendency was same when we used oxide coated disks. We concluded that this results were steno from the wetting characteristics change between molten metal and disk surface. Especially, due to the reactive properties of Ti and Zr with ceramic disk, the change of atomizing appearance and powder characteristics were noticeable.