• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.1
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• pp.1-11
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• 2012

This paper reports on a prototype cooling garment applying a cooling module. The cooling module was composed of a Peltier device, a cold sink, a heat sink and two fans. A constant box was used to evaluate the cooling effect of the module. Two cooling modules were attached on each side of the garment. The wear trial was conducted using 10 male subjects in an environmental chamber maintained at $30{\pm}0.5^{\circ}C$, $50{\pm}5%$RH. Subjective sensations of thermal, humidity, and comfort were surveyed. Statistical package SPSS12.0 was used for the t-test and the Wilcoxon signed-rank test. The results showed that most effective cooling module decreased the temperature of the constant temperature box by $-4.9^{\circ}C$. The micro-temperature of the cooling garment with a Peltier device was lower than the control garment during the exercise. In particular, the chest skin temperature was $1.5^{\circ}C$ lower with the cooling garment than the control. The maximum temperature difference was $-2.57^{\circ}C$ on the sides of the $1^{st}$ layer. Subjective thermal sensation from wear trials of the Peltier device attached garment was lower than the control garment. Subjects felt more comfortable with the cooling garment in almost all the periods.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.957-966
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• 1996

An attempt was made to measure the availability of waste heat, released from the cooling system of a small engine, which can be utilized for grain drying. An engine powered flat-bed rough rice dryer was constructed and the performance of the dryer with available engine-waste heat was analyzed for 10 , 20, 30 and 40 cm rough rice bulk depths with a constant dryer base area of 0.81$m^2$/min. The waste heat was sufficient to increase the drying air temperature 7 to 12$^{\circ}C$ at an air flow rate of 8.8 to 5.7㎥/min, while the average ambient temperature and relative humidity were 24$^{\circ}C$ and 70%. The minimum energy requirement was 3.26 MJ/kg of water removed in drying a 40 cm deep grain bed in 14h. A forty to fifty centimeter deep grained seems to be optimum in order to avoid over-drying in the top layers. On the basis of minimum energy requirement (3.26 MJ/kg ) , an estimation was made that the waste heat harvest from an engine of a power range of 1 to 10.5PS can dry about 0.1 to 1 metric on of rough rice from 23% to 15% m.c. (w.b) in 12 h at an average ambient temperature and relative humidity of $25^{\circ}C$ and 80%, respectively. The engine-waste heated grain dryer can be used in the rural areas of non industrialized countries where electricity is not available.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.67-73
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• 2022

The food cold chain refers to a technology and distribution supply chain applied to maintain a constant temperature suitable for the product from production (harvest) to delivery to consumers. In particular, in Korea, the insulation material used in the food cold chain is mostly EPS (Expanded Polystyrene), which is used as a transport container for various food cold chains. However, according to the government's eco-friendly policy, companies charge environmental contributions to the use of EPS, but due to its low price and convenience of handling, it is still used as a container for delivering food. In this study, in order to measure the domestic delivery environment of general refrigerated foods, changes in impact, temperature, and humidity during transport of the EPS packaging system containing foods and ice pack refrigerants were measured. As a result, there were 2?3 sections in which a high impact force of 40 G or more was generated during transport. This can cause damage to the product and EPS container. The difference in temperature and humidity changes by parcel transport routes is more than 30%, so it is necessary to present accurate standards for the domestic cold chain distribution environment. As a result of microbial experiments. the transportation period had a dominant effect on the increase in total viable count and E. coli count.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1479-1483
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• 2008

The three main physiological functions of nose are air-conditioning, filtering and smelling. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal and deformed nasal cavity models by PIV under both constant and periodic flow conditions. In this time, airflow inside normal nasal cavity is investigated numerically by the FVM general purpose code. The comparisons with PIV measurement are appreciated. Heat and humidity transfer is dealt numerically. Dense CT data and careful treatment of model surface under the ENT doctor’s advice provide more sophisticated cavity models for both PIV experiment and numerical grid system. Average and RMS velocity distributions have been obtained for inspirational and expirational nasal. Temperature distribution, heat and humidity transfer through the mucosa are obtained.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.187-187
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• 2011

Nowadays, the issue of solar cell durability in local weather and environment is a crucial issue. Above all, surface corrosion on solar cell multilayers is a major factor that determines the durability of commercial solar cells; corrosive chemical interactions between air, humidity and chemical species and solar cell multilayers can unfavorably affect the durability. Here, we study microscopic and spectroscopic surface techniques to investigate the corrosive interaction on the antireflective layers of solar cell multilayers under various conditions such as acid, base, constant temperature and humidity. Surface morphology and adhesion force were characterized with atomic force microscopy before and after chemical treatment. Chemical composition, and transmittance factors were studied with X-ray photoelectron spectroscopy, and ultraviolet-visible spectroscopy, respectively. Based on these studies, we suggest the dominant factors in the corrosive chemical processes, and their influences on the structural, compositional, and optical properties of the antireflective layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.152-155
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• 2006

Carbon nitride ($CN_X$) films were prepared by reactive RF magnetron sputtering system at various deposition conditions and the C-V characteristics of MIS(metal - insulator - semiconductor) capacitors that have the structures of Al/$CN_x$/p-Si/Al and Al/$CN_x$/$Si_3N_4$/p-Si/Al were investigated. The resistivity of carbon nitride was above $2.40{\times}10^8{\Omega}{\cdot}cm$ at room temperature. The C-V plot showed a typical capacitance-voltage characteristics of semiconductor insulating layers, while it showed hysterisis due to interface charges. Amorphous carbon nitride (a-$CN_x$) films, that have relatively high resistivity and low dielectric constant could be useful as interlayer insulator materials of VLSI(very large-scale integration) and ULSI(ultra large-scale integration).

• Journal of Korean Society of Forest Science
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• v.1 no.1
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• pp.1-6
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• 1962

Hysteresis Loops explaining relationship between E.M.C. and relative humidities of some commercial woods grown in Korea which have not been inspected were studied. Because of Hysteresis Loops are differently constructed among species, the loop of each species is necessary to plot in order to apply for seasoning of wood directly. Therefore relationship between E.M.C. and relative humidities, and Hysteresis Loops were inspected and compaired between species. Small sized ($3{\times}3{\times}1.3cm$) twenty pieces of wood blocks for each species were taken from log which cut few years ago and already attained air dry condition. Five relative humidity conditions (9, 32, 58, 82 and 91%) were controlled to keep constant in the cabinet under temperature $25^{\circ}C$. According to the results, it is concluded that there are considerable differences on the E.M.C. among two types of sorption, eight species and five different relative humidity conditions. Adsorption and desorption curves are showing characteristic Sigmeid Curves and desorption curves always are on the adsorption curves at all compaired species. Average hysteresis ratio is 0.75, the constructed loops of tested species are showing open hysteresis generally and flatten loop constructions of Qnerets aemitissima and Robinia pseudoaeaeia of hard wood species than other soft wood are considered to be established by differences of stability between hard and soft wood.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.5
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• pp.31-36
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• 2010

When corrugated board is folded at the severely low humidity condition, crack can occur along the scored (or creased) lines of linerboard. This phenomenon is called as score (or crease) crack. It is mainly resulted from the excessive concentration of stress on the outer layer of linerboard. To overcome score crack, many approaches including the installation of constant temperature and humidity system, displacement of low grade raw material by long and strong fibers, or application of water have been tried. We examined the effect of the weight fraction of top layer in two-ply sheet, freeness of top layer stock and wet pressing on strain and elastic modulus of sheet to prevent score crack. Lower freeness and higher press load increased the density and elastic modulus of sheet. Pressing load over the $50kgf/cm^2$, however, decreased the strain of sheet. The weight fraction of top layer had positive effect on strain as well as elastic modulus without increasing the density of sheet.

• The Korean Journal of Ecology
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• v.8 no.4
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• pp.201-204
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• 1985

The author reared the bandwinged grasshoppers, Oedaleus infernalis infernalis in the growth cabinet controlled as temperature of 25。C and 30。C under the conditiion of photoperiod 16L:8D, light intensity 510$\pm$240lux, relative humidity 65$\pm$3%. The results are summarized as follows: The female has six instars and male five instars. The larva reared in the temperature of 25。C died at the second larva stage, and the development to the third instar was impossible. The developmental periods of the egg stage of both sexes in the 30。C are 24.06 days. In the larval development periods, the fourth statge (19.73 days) was longer than that of any stage, and the second stage has the shortest period (9.9 days) in female. In male, the developmental period (9.59 days). The total developmental periods of female and male from the egg to the fifth instar were approximately 95.02 and 95.04 days, respectively. The total developmental period of female was as long as the period (15.75 days) of sixth instar which is not in the male. The survivorship curve in the temperature of 30。C shows concave type.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.843-851
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• 2022

This paper was conducted to study the conditions for the manufacture and operation of artificial snow removal and ice-making test facilities so that the test equipment can be tested in a low-temperature environment using the polar environment performance test facility. The polar environment performance test Facility is designed to artificially simulate extreme environments up to -65 ℃, and is a mid-to-large low-temperature environment test facility that can perform performance tests on offshore plant equipment, ships, leisure, and offshore structures. To verify the safety of deck work of ships operating in polar environments, artificial snow removal and artificial ice making devices were manufactured, and we conducted research on various operating environments using these facilities. For the efficient operation of artificial snow and ice making facilities, it is important to continuously supply dry air, and it has been found that installing an additional heater at the tip of the nozzle is effective in preventing freezing.