• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.145-155
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• 2009

There is a great deal of merit in CR system but artifact not produced in old system of film or screen newly is created. we studied 3 cases of artifact with CR system in one hospital, Gwangju. In the first case of the delay time and density, As the time was delayed, the density of the artifact was increased up to 67 percent in the natural radiation. The Second, Fading of the artifact decreased 33 percent in the rate of the emission after 10 hours, and the more the time was delayed, the less the quality of image was deteriorated. Third, Artifact was produced by the collimation when the radiologic technologist was performed, and by the Guiding plate and Suction cup when the radiation equipment was done. Therefore, when health care provider have to understand the artifact exactly and check regularly, the quality of the picture and the satisfaction of the medical examination is increased.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.63-74
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• 2016

The objective of this study was to investigate the variations of physico-chemical properties during the swine manure composting, sawdust as the bulking agent was composted at different points (Top layer, Side of middle layer, Bottom layer). Air suction system with constant bottom aeration in bench scale reactors (30 L). The highest temperature was reached in the range of $58^{\circ}C$ to $62^{\circ}C$ on $3^{rd}$ day and this thermophilic phase (> $50^{\circ}C$) was continued for 3 days in all the treatment mixtures. However, the temperature was gradually decreased to room temperature at the end of 60 day composting process. Except control, the discharged ammonia ($NH_3$) was a maximum in the treatment order of Top layer>Bottom layer>Side of middle layer as 500 ppm, 162 ppm and 120 ppm, respectively, on the $4^{th}$ day and showing that Top layer point Air suction produce much more ammonia content than the other point. During the composting process, the total Kjeldahl nitrogen (TKN) was gradually increased due to the mass loss in the composting mixtures. At the same time, C/N ratio was decreased to Top layer, 13; Side of middle layer, 12 and Bottom layer, 13 at Air suction points. The significant reduction of C/N ratio in all different air suction system when manure was matured. The $NH_4-N$ to $NO_3-N$ ratio was recorded as 10.52 at the initial stage of the compost mixtures and reduced to 0.97 (Top layer), 0.70 (Side of middle layer), 3.2 (Bottom layer) because of manure decomposition. The overall results revealed that Top layer and Side of middle layer Air suction is a suitable option when compared other point for high quality composts.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.2
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• pp.59-67
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• 2017

The aim of this experiment was to investigate the effect of air suction rate (SR) during the composting process of swine manure mixed with sawdust used as a bulking agent. In the 25 L composting reactors, the suction rate (SR) was at four different treatment levels (100%, 200%, 300%, 400%), and were fixed on the based on constant aeration rate into the composting mixtures. The temperature reached to thermophilic phase within 2 days and it was maintained up to the $5^{th}$ day of the composting process in all reactors and then gradually decreased to room temperature at the end of the composting process. The moisture content (MC, %) of the initial mixtures was 64.27%, and it was reduced to 38.4, 33.08, 14.59 and 11.93 in the different suction rate of 100%, 200%, 300%, 400%, respectively in the end process. During the composting, the level of pH was increased from 6.83 to 8.67 and it gradually decreased to 7.56 in 100% and 200%(SR). At the same time, the pH values were reduced only up to 8.19 at 300%, and 8.08 at 400%(SR), showing that suction strengths of 100% and 200% were the better option for composting than those of 300% and 400%. The total Kjeldahl nitrogen (TKN) of initial composts mixtures was 2.3% and were changed in 3.3, 3.1, 2.5, and 2.3% at the end of the composting period from the 100%-400% (SR) variations respectively. These results also indicated that 100% and 200% (SR) were more affected by the dry mass loss as $CO_2$ and water evaporation. The initial value of C/N ratio was 25.17 and were significantly reduced to 11.88, 11.97, 14.31, and 14.72 at the end of the experiment, respectively from the 100%-400% (SR) variations. These results suggest that the suction rate (SR) of 100% and 200% relative to constant air supply would be the optimal conditions to produce high-quality compost.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.777-783
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• 2000

Composting by negative aeration is a reasonable proposition to control odor generated during composting process. Cattle manure and rice hulls mixtures were composted in a bin composting system by negative aeration. Continuous(CA) and intermittent(IA) aeration methods were applied to analyze the composting characteristics. The composting temperature and the ammonia emission during composting were investigated according to the aeration methods. The main problem for the negative aeration was the generation of condensate in the suction line of blower. The quantity of condensate was significant for continuous aeration. The aeration method should be modified to escape from the cooling effect of continuous aeration at the initial stage of composting. It took a longer time to finish a composting for intermittent aeration on account of lower aeration. It was concluded that the composting by negative aeration could be accomplished by either continuous or intermittent aeration method if the flow rate would be controlled more efficiently and the water vapor in suction line of blower could be removed effectively. Ammonia emission increased up to maximum value of 675ppm for continuous aeration while 300ppm for intermittent aeration. However, the cumulative value of ammonia emission was larger for intermittent aeration than for continuous aeration.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.1 no.1
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• pp.75-83
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• 1995

Traction is the treatment of choice for a small nuclear protrusion. The nucleus is soft and can be influenced by suction. Traction provides a method of improving on recumbency-the only effective treatment before traction was devised. The intention is to achieve rapid reduction by distraction the joint surfaces mechanically-a positive purpose-instead of merely avoiding the compression of the upright posture by putting the patient to bed and leaving him there. Recumbency, usually successful in the end, wastes an endless amount of the patient's time and money. Traction carries the further advantage of enabling the patient to be up and about, attending to his bussiness, during treatment. Traction brings the joint surfaces much farther apart than just lying in bed, a greater centripetal force acts on the protruded part of the nucleus. Traction has three beneficial effects; 1. Suction : a sub-atmospheric pressure induces a centripetal effect on the contents. 2. Distraction : increases the distance between the articular edges. X -rays have shown an increase in width of the joint of 2.5 mm. 3. Ligamentous tightening : the posterior longitudinal ligament tightens which then exerts centipetal force on a central protrusion.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.29-37
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• 2003

Using a wind tunnel testing, the aerodynamic load characteristics of an elliptic airfoil was described. The experimental data was obtained for angles of attack $-20^{\circ}$ to $+20^{\circ}$ with $2^{\circ}$ increments at a chord Reynolds number of $0.99{\times}105$ and $2.48{\times}105$. For each test case, chordwise suction pressure distributions and wake surveys were obtained. Static pressure measurements were made over a 10 sec averaging time at a 10 Hz sampling rate. For each case, wake survey was conducted with a pilot-static probe at 1.0c downstream from the trailing edge at very fine spacing to resolve the wake velocity deficit profile. As can be expected, suction pressure coefficient was increased with angle of attack. The normal force, CNmax, appeared peak value at the incidence angle of $12^{\circ}~14^{\circ}$, and the significant increase in profile drag at this range of angles of attack.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.3
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• pp.131-139
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• 2009

The simulation of refrigeration cycle is important since the experimental approach is costly and time-consuming. The present paper focuses on the simulation of a refrigeration cycle equipped with a capillary tube-suction line heat exchanger(SLHX), which is widely used in small vapor compression refrigeration systems. The present simulation is based on fundamental conservation equations of mass, momentum, and energy. These equations are solved through an iterative process. The non-adiabatic capillary tube model is based on homogeneous two-phase flow model. This model is used to understand the refrigerant flow behavior inside the non-adiabatic capillary tube. The simulation results show that both of the location and length of heat exchange section influence the coefficient of performance (COP).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.63-67
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• 2007

The high pressure turbopump carries out supplying the oxidizer in the liquid propulsion rocket in the combustion chamber. Because an LRE requires a very short starting time , the turbine at the turbopump experiences high torque that was produced by the high pressure and the high temperature. The purpose of this study is to evaluate a turbine blade surface temperature profiles at initial starting 0 ${\sim}$ 0.5 sec. Using $Fine^{Tm}$/turbo, three dimensional Baldwin-Lomax turbulence models are used for numerically analysis. The turbine is composed of 108 blades total, but only 7 rotors were considered because of periodic symmetry effect. Because of interaction with a bow shock on the suction surface, the boundary layer separates from suction surface at inner area of turbine blade. The averaged temperature of the turbine blade tip at 1000 rpm is higher than that of 9000 rpm. Especially at 1000 ${\sim}$ 9000 rpm, temperatures increases on the hub side of the turbine blade tip. Moreover at 9000 rpm, the temperatures from the hub to the shroud of the blade tip increase as well.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.6
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• pp.599-604
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• 2015

Currently, the coolant system in industrial sites is an efficient process to keep clean cutting oils. However, the damage to a pump occurs due to a chip and debris when inhaled into the pump, and thus problems such as the reduction of both efficiency and lifespan might arise. In this study, a new type of filter was developed in order to primarily prevent the damage from the pump impeller and make it unnecessary to have the replacement and cleaning at the same time. This study found the problem reducing the suction volumetric efficiency and cavitation when inhaled, and conducted a method to solve the problem compared to the result of fluid analysis according to two velocity conditions. As a result, this study achieved the effect of lowering the pressure and meeting the suction flow rate by connecting the four filters.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.53-60
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• 2010

The natural soils are classified in saturated soils and unsaturated soils according to level of ground water but the research for only saturated soils has been conducted by this time. However, there are many proble.ms which are not solved by using the concept and principle of saturated soils on the natural soils. In fact, it is known that unsaturated soils represent the behavior characteristic unlike completely saturated soils because of the adhesion under the influence of negative pore water pressure, the high angle of friction and the low water permeability by the air entry. So it needs to conduct the various researches on insufficient unsaturated soils. In this paper, unsaturated triaxial compressive tests are conducted in order to do research on shear strength characteristic on sands and silty sands of Nakdong river. As a result of the tests, the cohesion is increased in non-linear type according to the change of the matric suction, but the angle of internal friction is not changed much.