• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.2
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• pp.128-136
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• 2008

It is necessary to estimate the cooling load of the next day for effective control of ice thermal storage system. In this paper, new methodology is proposed to estimate the cooling load using design parameters of building and predicted weather data. Only six input parameters such as sensible heat coefficient and constant, latent heat coefficient and constant, maximum and minimum temperature are necessary to obtain hourly distribution of cooling load for the next day. Two benchmarking buildings(hospital and research institute) are selected to validate the performance of the proposed method, and the estimated cooling loads in hourly and daily bases are calculated and compared with the measured data for E hospital. The estimated results show fairly good agreement with the measured data for both buildings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2344-2349
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• 2015

In Korea, summer is hot and humid, and air-conditioners consume too much electricity due to large amount of latent heat. Simultaneous usage of dehumidifier may reduce the latent heat and save the electricity. In this study, dehumidification performance was measured in a constant temperature and humidity chamber for a small-sized dehumdification rotor made of inorganic fiber impregnated with metallic silicate. Variables were rotor speed, room temperature, regeneration temperature, room relative humidity and frontal velocity to the rotor. Results showed that there existed optimum rotor speed (1.0 rpm), and optimum regeneration temperature ($100^{\circ}C$). Above the optimum rotor speed, incomplete regeneration is responsible for reduced dehumidification. Above the optimum regeneration temperature, increased temperature difference between regeneration and dehumidification process is responsible for reduced dehumidification. The amount of dehumidification also increases with the increase of relative humidity, dehumidification temperature and flow velocity into the rotor.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.667-672
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• 2011

The purpose of this work is to present the experiment results by a dynamic adsorption of water vapor on pelletized zeolites (ADZ300, ADZ400, and ADZ500) in fixed bed. The breakthrough curves of water vapor with several different concentrations and temperature in the range of 25~45 $^{\circ}C$ on zeolite bed were investigated. In the same conditions, the breakthrough time on ADZ400 and ADZ500 were little longer than ADZ300, and the equilibrium adsorption capacity on ADZ500 was highest. The higher the concentration of water vapor was, the faster the breakthrough time was, and the slope of breakthrough curves showed a tendency to increase. The faster the flow rate of water vapor was, the faster the breakthrough time was relatively, but variations between flow rate and breakthrough time did not have a proportional relationship. The breakthrough curve maintained constant gradient in spite of variation of flow rate in the same concentration. The temperature rise in zeolite bed by adsorption heat was occurred in the early stage of adsorption. After water molecule layers were formed on the surface of zeolite, the temperature was slowly cooled by water vapors continuously flowed in as constant temperature. The greater the concentration of water vapor and adsorption temperature were, the temperature difference in zeolite bed was increased.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.2
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• pp.159-162
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• 2012

The Chinese windmill butterfly, Atrophaneura alcinous, is an important butterfly for exhibition in butterfly garden. The objective of this study was to determine the effect of temperature on A. alcinous in the laboratory. Development of A. alcinous reared on leaves of Aristolochia contorta was investigated at five constant the laboratory condition (20, 22.5, 25, 27.5 and $30^{\circ}C$) and at relative humidity of 60% with a photoperiod of 14:10 (L:D). Temperatures have been suggested as an important determinant of developmental rate, lifespan and mortality in invertebrates. As the temperature increased, the length of the developmental period gradually decreased. The developmental time (pupation) from egg hatching to pupation was respectively 25.8, 23.6, 19.6, 15.5, and 12.9 days at the temperatures of 20, 22.5, 25, 27.5 and $30^{\circ}C$. And pupation was respectively 40.0, 30.0, 63.4, 50.0, 23.3% at the temperatures of 20, 22.5, 25, 27.5 and $30^{\circ}C$. The developmental threshold temperature estimated for egg-to-pupae was 10.8, with a thermal constant of 230.4 degree-days. Therefore, the optimal developmental temperature for A. alninous was determined to be $25^{\circ}C$. To compare the effects of the total duration of chilling on the termination of diapause, larvae were subjected to a temperature of $8^{\circ}C$ from 60 to 120 days. The rate of termination of diapause was significantly higher at 60 days compared to other incubation period.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.427-434
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• 2000

In tradition, there have been two kinds of drying methods, which are sun drying and artificial drying. The sun drying method which has been adopted traditionally has been replaced by the hot-air drying method which is one of the most general methods of artificial drying, with its simple drying system, low initial cost of drying plant, and easy operating method. But the hot-air drying method has some defects; (1) much energy loss happens due to the discharge of hot air during the drying process, (2) control of drying rate is not easy on account of changing relative humidity of inlet air for uniform hot air temperature, (3) high temperature of foods in drying process brings about the production of low-grade drying products. Vacuum drying takes advantage of energy saving and mass production because it reduces the drying time by increasing the drying rate under low temperature condition. The aim of this paper is to develop the low temperature vacum dryer, with low initial investments and operating costs, easy operating method and trouble-free operation.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.425-435
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• 2020

This study aims to investigate the impact of the physical structure, such as altitude, slope gradient, slope direction, and topographical structure, and the vegetation pattern, such as existing vegetation, diameter of breast height (DBH), and crown density, on climate. The analysis results showed the significant difference in relative humidity, wind speed, and solar radiation at varying altitudes, the significant difference in all climate factors except for the wind speed at varying slope gradient, and significant difference in temperature and relative humanity at varying slope direction. The topographic structures were divided into valleys, slopes, and ridges. They were found to differ in relative humidity. However, the differences between constant trends and types were found to be insignificant concerning temperature, wind speed, and solar radiation. Significant differences in temperature, relative humidity, and wind speed were recorded with changing existing vegetation. The DBH showed a significant difference in temperature, wind speed, and solar radiation. The crown density showed a significant difference in temperature and solar radiation. The result of the relationship analysis for the analysis of the effect of vegetation pattern and physical structure on the meteorological environment showed that temperature was affected by slope gradient, slope direction, DBH, and crown density. The relative humidity was correlated with the altitude, slope gradient, slope direction, and topological structure in physical structure and the existing vegetation and crow density in vegetation pattern. The wind speed was correlated with the altitude, existing vegetation, and DHB, and the solar radiation was correlated with the slope gradient, DHG, and crown density. The crown density was the most overall significant factor in temperature, relative humidity, and solar radiation, followed by the slope gradient. DBH was also found to be highly correlated with temperature and solar radiation and significantly correlated with wind speed, but there was no statistically significant correlation with relative humidity.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1207-1208
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• 2006

We developed the copper core ball electroplated with Sn-Ag-Cu of the eutectic composition which used mostly as Pb free solder ball with high reliability. In order to search for the practicality of this developed copper core ball, the evaluation was executed by measuring the initial joint strength of the sample mounted on the substrate and reflowed and by measuring the joint strength of the sample after the high temperature leaving test and the constant temperature and the humidity leaving test. This evaluation was compered with those of the usual other copper core balls electroplated with (Sn,Sn-Ag,Sn-Cu,Sn-Bi) and the Sn-Ag-Cu solder ball.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.245-250
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• 2003

In order to control indoor air quality and save energy, it is needed to install a suitable ventilation system equipped with heat exchanger for heat recovery. The purpose of this research is to find the performance of paper heat exchanger for exhaust heat recovery, which exchanges latent heat as well as sensible heat. Experimental apparatus comprises heat exchanger model, constant temperature and humidity chamber, fan and measurement systems for temperature, pressure and flow rate. Thermal performance and pressure loss of the paper heat exchanger are measured and compared at various air velocities and outdoor conditions. Experimental results show that paper heat exchanger can recover $50{\sim}70%$ of the enthalpy difference between supply and exhaust air.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.62-68
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• 1978

Equilibrium moisture content of rough rice is an important factor because it has a close relationship to storage and drying problems. Determination of the EMC for 10 different varieties of rough rice were made in atmospheres of various constant humidities at three different constant temperatures. In addition , some physical properties were also measured for two different levels of moisture content of the samples. The results may be summarized as follows ; 1. Several physical properties of ten different varieties of rough were measured. Significant difference of the properties was appeared between the varieties in which the difference was pronounced in the dimensions of the varieties. Also, all the dimensions were increased as the moisture content of the rough rice was increased from 14 % to 16%. 2. Significant difference of the equilibrium moisture content was also appeared between some of the varieties in which the equilibrium moisture content of Josaengtongil and Minehikari was 24.26% while that of the others was in the range between 18 to 19% at the conditions of relative humidity of 84% and temperature of 47℃ , respectively. Similar pattern was also observed in other conditions. 3. The values of the constant of Henderson's equation were calculated from the data obtained but they are believed to be useful until more precise and complete data are obtained. There was a good agreement between the calculated and experimental results.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.458-463
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• 1996

Fresh ginger harvested in Seosan, Choongchengnam-do, was used to investigate the pretreatment effect before long-term storage. Wounded ginger were cured at the temperature of 25, 30, $35^{\circ}C$ and the RH 83 and 93% for 1, 3, 5, 7 days, respectively Then the cured ginger were stored in the laboratory scale storage room ($12^{\circ}C,$ 95% RH) in order to find out the optimum curing condition. At a constant temperature and a RH. the longer ginger were cured, the more their weight was decreased; at a constant temperature and a curing period, the higher RH was, the less weight was lost. During the curing process, sprouting rate was accelerated at temperature higher than $30^{\circ}C$ and humidity higher than 90%; mold growing was observed at any temperature and humidity, but especially at $35^{\circ}C$ the rate was relatively faster when the curing time was increased. Hardness of wound surface cured at 93% RH was relatively higher than those cured at 83% RH at all temperatures. The weight loss of store ginger after curing was $2.0{\sim}8.2$ after 30 days and $7.2{\sim}14.2%$ after 60 days storage. Compared with all results through a screening procedure, the condition of 3-days curing at $25^{\circ}C$ and 93% RH showed th best result for minimizing quality changes during storage.