• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.82-87
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• 2011

Lubrication has an important role to reduce frictional forces and temperature between cutting chips and the face of a tool. However, it has harmful effects to workers' health and working environment. The purpose of this thesis is to find cutting conditions through the quality analysis in boring for SM45C steel using MQL(Minimum Quantity Lubrication). Machining process is super drill, tip drill, end mill and boring in order. Experimental factors of boring and the quantity of mist air are properly selected. With the analysis of experimental data, this thesis shows that boring with MQL improves the surface roughness when spindle speed is 934rpm or feeding speed is 74mm/min.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.117-123
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• 2011

The purpose of this study is to show the friction and wear characteristics on the vapor deposited coating layers on the SCM415 steel. In this research, frictional wear characteristic of coating materials such as Ti-series, Cr-series & WC/C and TiAlN+WC/C multilayer coating was investigated under room temperature, normal air pressure and no lubricating condition. Therefore, this study carried out research on the friction coefficient, micro hardness(Hv), surface roughness and wear quantity on the vapor deposited coating layers on the SCM415 steel. As the wear experimental result, the excellence of TiAlN+WC/C multilayer coating has been proven by high micro-hardness, low friction coefficient and wear quantity.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.465-470
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• 2001

The entrainment of air into spray jets has been considered. Entrainment is defined as the quantity of ambient gas that is drawn into a spray. Numerical study is performed to investigate an air entrainment into spray jets and compared with results of experiment of air entrainment. Experimental measurements were performed with PDA and PIV system. Experimental and numerical results show that the air entrainment was affected droplet size and velocity.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.4
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• pp.100-107
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• 2007

We proposed the concatenation of logistics' Information to constructing the intelligent logistics city that is to manage efficiently cargo distribution as providing at real-time information of cargo location trace and management through the Telematics/RFID. Case of the Incheon of the "Air Logistics Hub", this area is on an increasing trend on the quantity of cargo transport of the Air & Sea cargo system until 2006. As intelligent project of the Air's and the Sea's field is independently developed at each area, it is a problem on the concatenation of logistics' information such as freight location trace and management, operation management and route information of cargo vehicles. Therefore, we propose the advanced transport service model for the concatenating smoothly of Air & Sea cargo system. In this paper, we only manage the model of Air & Sea cargo system of the advance logistics city.

• International Journal of Automotive Technology
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• v.3 no.2
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• pp.57-62
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• 2002

It is well known that the entrained air in oil causes appreciable reduction in the stiffness of hydraulic systems. It makes the response delay of the systems and sometimes destroys the stability. Because the hydraulic systems of automatic transmissions are operated in relatively low pressure and high temperature, it is very important to analyze the effects of the air included in automatic transmission fluid. However, it is difficult to derive the generalized model to describe the effective bulk modulus theoretically or measure it in actual operating conditions of automatic transmissions. This paper reviews previous studies of the air effects in hydraulic systems and the measurement techniques of the effective bulk modulus in operating conditions. Based on this work, the theoretical model with moderate complexity and the measurement technique of the effective bulk modulus considering entrained air effect at real operating conditions are suggested. Our paper also shows that the quantity of the entrained air in the automatic transmission fluid can be estimated from the experimental results.

• Journal of ILASS-Korea
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• v.5 no.3
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• pp.9-16
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• 2000

In a SI engine, three-way catalyst converter has the best efficiency when A/F ratio is near the stoichiometry. The feedback control using oxygen sensors in the commercial engine has limits caused by the system delays. So it is necessary to control fuel quantity in accordance with intake air amount in order to reduce exhaust emission and improve the specific fuel consumption. Precise A/F ratio control requires measurement of air amount with respect to the cylinder and injection fuel according to the air amount In this paper, we applied nonlinear fuel injection model and developed the algorithm of A/F ratio control. This algorithm includes the methods of measurement of transient air mass flowing into each cylinder, of calculation of injection pulse width for measured air mass, and the method of feedback and engine control by using lambda sensor. Also we developed control program for IBM-PC by using C++ Builder, and tested it in the commercial engine.

• Transactions of the KSME C: Technology and Education
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• v.2 no.2
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• pp.105-111
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• 2014

Generally the lower part of the Earth's atmosphere, which is 20km above the ground, is called "air." The composition of this area is almost consistent consisting of nitrogen, oxygen, and other gases. Air density refers to the mass per unit volume of earth atmosphere. Though air is made of the mixed gases in a constant composition, the water vapor is one of the very changeable components. The density of moist air is lower than the dry one at the same temperature and pressure. As the density varies according to the pressure and temperature, this paper attempts to explore the main factors in the air quantity calculation by examining first the density calculation process according to the air property, and second the relation between the actual and standard air flow.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.2
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• pp.3430-3437
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• 1974

.It is very importaut to know the water consumption of crops in planning irrigation works and practicing suitable soil moisture management. For the purpose of making it clear that how much water be consumed to cultivate the Chinese cabbage, Chamber method has been applied. Main equipments in the transpiration chamber are flowers, manometer and electric thermograph. The chamber made of vynyl plate has a small entrance at the base and an exit at the top, and the ventilation in the chamber was carried out by a flower through the entrance and exit. Air-flow adjusted by an orifice manometer enters the chamber from the outside over the crop canopy through the pipe like a chimney and finally goes out to the outside. Two sets which consist of a pair of dry and wet bulb made by thermistor are installed in the entrance and exit tube, and record air temperature automatically. Evapotranspiration amount is computed from the air-flow quantity and difference in absolute humidity between at the entrance and exit of the chamber by the following equation: ET=(X2-X1)${\times}$Q where ET=evapotranspiration amount X1=absolute humidity at the entrance(g/㎥) X2=absolute humidity at the exit(g/㎥) Q=air-flow quantity(㎥) This study was carried out at the upland farm of the Institute of Agriculture Engimeering and Utilization, Suwon, Korea. from 1971 to 1973. The results obtained in this experiment are as follows: 1. The total amount of evapotranspiration of Chinese Cabbage that is cultivated in autumn is 408.1mm during growth period. 2. Chinese cabbage rapidly grows up in the second ten days of September, 40th to 50th days after seeding. At the same time, the maximum amount of evaportranspiration of Chinese cabbage is 61.6mm/10 days 3. The correlation between Pan-evaporation and evapotranspiration is high, coefficient of correlation r=0.88**, and can be shown as The following regression equation: ET=0.913E+20.273 4. Evapotranspiration is closely related with meteorological factors: r=0.85**, for insolation, r=0.76** for air temperature, respectively. 5. The percentage of evapotranspiration amount, at the beginning of growth stage, gradually increases in proportion as the Chinese Cabbage grows but is largely affected by meteorological factors after the green cover formation. 6. By Blaney and Griddle formula, evaportranspiration coefficient "K" are within from 0,85 to 1.27.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.844-849
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• 2008

In recent semiconductor manufacturing clean rooms, in order to improve clean room air quality, air washers are used to remove airborne gaseous contaminants such as $NH_3$, SOx and organic gases from outdoor air introduced into clean room. Meanwhile, there is a large quantity of exhaust air from clean room. From the energy saving point of view, heat recovery is useful for the reduction of air conditioning energy consumption for clean room. Therefore it is desirable to recover heat from the exhaust air and use it to reheat the outdoor air. However, so far there have not been sufficient studies of analyzing the comparison of the amounts of energy consumption and saving. In the present study, an experiment was conducted to investigate the energy consumption and heat recovery of a fin-coil type air washer system for semiconductor manufacturing clean rooms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.11-17
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• 1976

Put four different kinds of Jangdongsi, Pasi, Gamsi, and Taebongsi etc. into glass bottle(Fig. 1) of 1150ml and after modulated constitution of air girding this, by means of $CO_2$ the keep in cold storage on $0{\sim}5^{\circ}C$. The results are as follows : 1. $CO_2$ non-addition group was not changed it's own color to four months regardless of kind of persimmons 2. $CO_2$ added test group by double quantity of container was not more rapidly discoloration. 3. One - half quantity of test group added double, same, one-half and one of fifth quantity of container was the most effect, $CO_2$ as the same kind in S. T. P. 4. Taebongsi of test group of four different kinds added one-half quantity of $CO_2$ was maintained effectually possible it's natural color till seven months. 5. In taste, non-addition of $CO_2$ existed astringency taste but addition of $CO_2$ showed sweet taste like a Gamsi since two months of storage.