• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.356-362
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• 2018

Hot pepper is a kind of seasoning vegetables, which is a major item in the Korean vegetable market. Since the use of hot pepper is processed into pepper powder, which is a powder form of dried hot pepper, improvement of quality and productivity of dried hot pepper is important. Therefore, this experiment was conducted to suggest proper drying method by comparing the changes of hot pepper powder ingredients considering production cost according to the drying method. As a drying method, we used sun drying and heat drying which are widely used in practice. We also compared the productivity and quality of dried hot pepper by applying a dehumidifying drying method using a dehumidifier. Drying rate of hot pepper was highest of 85.1% at heat drying. Accordingly moisture content of hot pepper powder was lowest of 13.5% at heat drying. The American Spice Trade Association (ASTA) color value, which influenced the coloring of red pepper, showed higher in heat drying and dehumidified drying treatment than the sun drying treatment. The content of capsaicinoids was higher at sun drying treatment than that of at both heat drying and dehumidified drying treatments. The content of sugar was higher at heat drying and dehumidified drying treatment where drying time was relatively short than that of sun drying treatment. Also, there was no significant difference in sugar content between the two treatments. The production cost of dried hot pepper with dehumidified drying was 9.9% more efficient than heat drying. Through this study, it was found that heat and dehumidified drying method were effective in increasing sugar content and coloring of hot pepper powder. In order to improve the capsaicinoid content of red pepper, it is considered that appropriate drying temperature and drying time should be added in the process of heat drying and dehumidified drying.

• Clean Technology
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• v.14 no.1
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• pp.40-46
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• 2008

The dehumidifiers were prepared by the impregnation of the zeolites such as MCM 48, USY, beta on the silica ceramic paper. Their capacities for $H_2O$ absorption and regeneration of the bed were tested in a fixed bed reactor system. The $H_2O$ absorption capacities of the dehumidifiers impregnated with the zeolites were $1.5{\sim}2$ times higher than those without the zeolites. Especially, the humidifier using MCM 48 and colloidal silica showed an excellent capacity (42.1g $H_2O/g$ absorbent). It was found that the $H_2O$ absorption capacities of the dehumidifiers were improved because the amount of silica gel, the main component in absorbing $H_2O$, increased due to the large surface area and pore volume of the zeolites. In addition, $H_2O$ was easily desorbed from the dehumidifiers with zeolites at $80^{\circ}C$ of regeneration temperature and the desorption amount of $H_2O$ was the same as that absorbed. It was confirmed that the $H_2O$ absorption capacities of the dehumidifiers impregnated with zeolite were maintained without deactivation through the repeated cyclic experiments.

• Solar Energy
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• v.19 no.4
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• pp.45-53
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• 1999

This report Introduces a total heat exchanger in a solar air-conditioning system using Lithium Chloride(LiCl) solution. The hot and humid outside air is cooled and dehumidified by LiCl solution that is sprayed on the packed layer of the total heat exchanger. LiCl solution once diluted is concentrated again in a regenerator using solar energy. Three types as the packed materials were used in this experiment and the dehumidification performance was evaluated by the value of $k_xa(kg/h{\cdot}m^3{\cdot}{\Delta}x)$, overall mass transfer coefficient based on a humidity ratio potential difference, the influence of inlet LiCl solution flow rate, air flow rate, packed layer height on $k_xa$ was investigated. It was found that air flow rate, LiCl solution flow rate, packed layer height for all types had a great influnce on the value of $k_xa$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.206-211
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• 2016

Various applications require dry air at low temperature, such automation equipment, semiconductor manufacturing, chemical production lines, and coating processes for the shipbuilding industry. Four evaporators for low temperature (below $0^{\circ}C$) were installed for a dehumidification system. Moist air is cooled sequentially over three evaporators. The first evaporator has an evaporation temperature of $13^{\circ}C$, that of the second evaporator is $5^{\circ}C$, and that of the third evaporator is maintained at $-1.3^{\circ}C$. In the fourth evaporator implantation thereby the moisture contained in the moisture air. A pressure regulator (CPCE 12) is used at this point and is defrosted when the vapor pressure is below a set value. The non-implantation moisture of the air is a heating system that uses the waste heat of a condenser with high temperature. It develops the cooling type's dehumidifier, which is important equipment that prevents the destruction of protein and measures the temperature and humidity at each interval by changing the front air velocity from 1.0 m/s to 4.0 m/s. The cooling capacity was also calculated. The greatest cooling capacity was 1.77 kcal/h for a front air velocity of 2.0 m/s

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.732-740
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• 2019

Evaporative humidification using a humidifying element is widely used for humidification of a building or a data center. The performance of a humidifying element is commonly expressed as humidification efficiency, which is used independent of air temperature, humidity and water temperature. In this study, a series of tests were conducted at two air conditions (data center and commercial building) using two different humidifying elements (cellulose/PET and Glasdek) changing the frontal air velocity and water temperature. Results showed that the measured humidification efficiency was dependent on the air condition and water temperature. In fact, even dehumidification occurred at the inlet of the humidifying element at the air condition of commercial building. The reason was due to the inlet water temperature, which was lower than the dew point air temperature. As the difference between the inlet water and the dew point air temperature increased, the humidification efficiency decreased. This suggest that proper thermal model should account for the inlet region, where the amount of moisture transfer may be different from the other part of the humidification element. A simple analysis on the thermal performance of the cellulose/PET humidification element showed that the Sherwood number was adequately predicted, whereas the friction factor was ovepredicted, probably due to the simplification of the channel geometry and the neglection of the water film on the element surface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.326-331
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• 2018

Evaporative humidification using a humidifying element is used widely for the humidification of a building or a data center. The performance of a humidifying element is commonly expressed as the humidification efficiency, which is assumed to be independent of the air temperature or humidity. To verify this assumption, a series of tests were conducted under two air conditions - data center ($25^{\circ}C$ DBT, $15^{\circ}C$ WBT) and commercial building ($35^{\circ}C$ DBT, $21^{\circ}C$ WBT) - using humidifying elements made from cellulose/PET and changing the frontal air velocity from 1.0 m/s to 4.5 m/s. Three samples having a 100 mm, 200 mm, or 300 mm depth were tested. The results showed that the humidification efficiency is dependent on the air condition. Indeed, even dehumidification occurred at the inlet of the humidifying element at the air condition of commercial building. This suggests that a proper thermal model should account for the inlet area, where the amount of moisture transfer may be different from the other part of the humidification element. As the depth of the element increased from 100 mm to 200 mm, the humidification efficiency increased by 29%. With further increases to 300 mm, it increased by 42%. On the other hand, the pressure drop also increased by 47% and 86%.

• Membrane Journal
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• v.24 no.3
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• pp.213-222
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• 2014

In this study, 2-stage recirculation membrane process was developed for purification of high purity bio-methane for the vehicle fuel application. Pure gas permeation and mixture gas permeation test were done as a function of methane content and pressure in the feed using polysulfone membrane modules. 2-stage membrane plant was designed, constructed in a food waste treatment cite. Dehumidification, dry desulfurization, and desiloxane plants are installed for the removal of $H_2O$, $H_2S$ and siloxane in the biogas. Permeation test were done with the pre-treated methane mixture in terms of methane purity and recovery by adjusting the ratio of membrane area (1:1, 1:3, 2:2) in the first and second membrane modules in the plant. When membrane area of 2 stage increased to $3m^2$ from $1m^2$ at 1-stage membrane area of $1m^2$, the feed rate and $CH_4$ recovery at 95% methane purity were increased from 47.1% to 92.5% respectively. When the membrane area increased two-fold (1:1 to 2:2), $CH_4$ recovery increased from 47.1% to 88.3%. When the feed flow rate was increased, in 1:3 ratio, final purity of the methane is reduced, the methane recovery is increased. When operating pressure was increased, the feed rate was increased and recovery was slightly decreased. From this result, membrane area, feed pressure and feed rate could be the important factor to the performance of the membrane process.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.987-995
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• 2009

The effects of Kwamaegi on serum lipid profiles and ROS(reactive oxygen spices) generating and scavenging enzyme activities were investigated in rats. The three experimental groups were divided as follows: normal control diet group (NC), 5% naturally prepared and freeze-dried Kwamaegi supplemented diet group (NPK) and 5% chitosan-ascorbate treated and artificially dried (CWDD: Chilly Wind & Dehumidification Drier) Kwamaegi supplemented diets group (CAK). There were no significant differences in weight gain, feed intake, feed efficiency ratio or organs weights per body weight including liver, kidney, heart and spleen among the group. In addition, there were no significant differences in serum triglyceride and total cholesterol contents. The HDL-cholesterol contents of the NC, CAK and NPK groups were 62.00, 36.48 and 78.44 mg/dL while LDL-cholesterol contents were 62.00, 36.48 and 78.44 mg/dL, respectively, which were significantly different. The atherogenic indeces in the experimental groups were 0.62, 1.20 and 0.13, respectively. There were no significant differences in total XOD (xanthine oxidoreductase) activities; however XOD type O activity was higher in the NPK group than un the NC group and in the CAK group XOD type O activity was 21~45% lower compared to NC and NPK groups. SOD (superoxide dismutase) activity was significantly higher in the CAK group than in the NC and NPK groups, while there were no significantly differences in GST (glutathione S-transferrase) activity among the groups. Furthermore, serum ALT activity was higher in the NPK group versus the NC and CAK groups. GSH (glutathione) content was higher and LPO (lipid peroxide) content lower in the CAK group compared to the NC and NPK groups. Forem the above results, we suggest that CA treated and artificially dried Kwamaegi is not only a hygienic product but also has lowering effects on LDL-cholesterol and the atherogenic index together with the lowering of ROS-generating and increasing of ROS-scavenging enzyme activities compared to other natural products.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.844-861
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• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.