• Journal of Power System Engineering
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• v.9 no.2
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• pp.93-98
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• 2005

The performance of cooling tower is dependent on the thermal performance of the packings. It's assessed by heat transfer rate and fan power. In this study, new packing was developed for application in compact type cross-flow cooling tower. The packing characteristic curve and the pressure drop curve were obtained by measuring packing characteristic values and pressure drops of small sized filler in comparison to existing mid-large sized filler. The heat transfer characteristics on small sized filler are about 66% higher than existing mid-large sized filler. The pressure drop characteristics on small sized filler are about two times of the pressure drop characteristics on existing mid-large sized filler.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.3
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• pp.358-367
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• 1998

Since the performance of cooling tower is strongly dependent on the thermal performance of the packing, the evaluations of heat transfer rate and fan power from various packing have attracted intense interest. In the present study, two new packings have been devised and their performances have been compared with those of two existing packings to find better shape characteristic. It is found that one of the existing packings, which showed high heat transfer rate and medium fan power due to zig -zag flow passages and highly irregular surfaces, should be adapted.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.129-134
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• 2000

Recently, HIPS(High Impact Polystyrene) materials are spot-lighted as office equipment, home electronics, electronics appliances housing, packing containers, etc. But its using are occur to problem caused by fatigue fracture. However, its strength is larged affected by environmental conditions. So, in this paper it tried to analyze the effect of temperature by tensile test and fatigue test. It was observed that yield strength and ultimate strength, fatigue life of same stress decreased relatively with increase temperature. Further, this paper predict S-N curve using the result of tensile test and micro vickers hardness test. For this purpose, the management in the engineering department is able to design the fatigue life of HIPS(HR-1360) materials.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.265-272
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• 2000

This study introduces the current theory of the SWCC and tries to verify the theory by performing laboratory tests for the local soils of Korea. First, the SWCCs of Poi-dong soil and Shinnae-dong soil, the most typical weathered residual soils in Korea, were experimentally obtained and the results were compared among others. Second, a SWCC model for deformable soils was proposed. For deformable soils, which show huge volume change during desaturation, the volume change behavior should be considered, and the SWCC should be expressed as a function of void ratio as well as suction.

• Polymer(Korea)
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• v.26 no.4
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• pp.516-522
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• 2002

The ion exchange characteristic of quaternary ammonium as functional group containing aminated acrylic fibrous ion exchanger were studied for the adsorption of linear alkylbenzene sulfonate (LAS) in a continuous ion exchange process. The adsorption capacities of aminated acrylic for LAS as the adsorption temperature were increased with increasing adsorption temperature and were equilibrated at $40^{\circ}C$. The maximum adsorption capacities as column packing ratio (L/D) were obtained at L/D>2. The adsorption capacity for LAS was increased with increasing pH and the maximum adsorption capacity as pH was obtained at pH 7. The effects of temperature and pH were similar to those of flow rate and concentration of LAS tin the breakthrough curves, the breakthrough time and slope of breakthrough corves decreased with increasing flow rate and concentration of LAS in adsorption process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.763-769
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• 2010

In recent times, there has been considerable interest in HIPS (High Impact Polystyrene) materials for their use in construction of office equipments, home electronics, housing for electronics appliances, packing containers, etc. However, these materials suffer from problems caused by fatigue fracture. Further, their strength is substantially affected by environmental conditions. Therefore, in this study, the effect of temperature was analyzed by performing a tensile test and a fatigue test. It was observed that the yield strength, the ultimate strength, and the fatigue life decreased relatively with an increase in temperature. Further, an S-N curve can be predicted by using the results of the tensile test and a micro-Vickers hardness test.

• Progress in Medical Physics
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• v.14 no.4
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• pp.225-233
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• 2003

The goal of a radiation treatment plan is to deliver a homogeneous dose to a target with minimal irradiation of the adjacent normal tissues. Dose uniformity is especially important for stereotactic radiosurgery using a linear accelerator. The dose uniformity and high dose delivery of a single spherical dose distribution exceed 70％. This also results with a similar stereotactic radiosurgical plan using a Gamma Knife. The dose distribution produced in a stereotactic radiosurgical plan using a Gamma Knife and Linear accelerator is spherical, and the application of the sphere packing arrangement in a real radiosurgical plan requires much time and skill. In this study, we found a characteristic of dose distribution with transformation of beam parameters that must be considered in a radiosurgical plan for effective radiosurgery. First, we assumed a cylinder type tumor model and a cube type tumor model. Secondly, the results of the tumor models were compared and analyzed with dose profiles and DVH_(Dose Volume Histogram) representative dose distribution. We found the optimal composition of beam parameters_(i.e. collimator size, number of isocenter, gap of isocenters etc.), which allowed the tumor models to be involved in the isodose curve at a high level. In conclusion, the characteristics found in this study are helpful for improving the effectiveness and speed of a radiosurgical plan for stereotactic radiosurgery.