• Journal of Ginseng Research
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• 제16권2호
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• pp.111-123
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• 1992

Drying characteristic data for peeled ginseng were obtained to determine dominant drying factors and fitted with five selected drying models and an empirical model. Among air temperature, relative humidity and diameter of ginseng root, drying air temperature was found to be the most influencing factor on drying rate. Drying velocity appeared faster as the drying temperature increased but its effect was less at high temperature than at low temperature. Quality change during the drying process did not occur except when relative humidity was 75fb. At high relative humidity, skin color of ginseng was turned to light brown. Approximate-Diffusion and the Empirical model for drying were in a good agreement with experimental data. The models are as follows; $.$ Approximate-Diffusion model MR = A$.$exe(-k$.$1) A = 1.72 + 0.407 In(D) - 0.0000963T3 - 0.358 In(RH) + 0.0000945 RH2 B= 1.01 + 0.0195RH - 0.O0518D2 + 0.0708 In(T) - 0.492 In(RHI-D.0000933RH2$.$Empirical model MR= Cl + Cs$.$In(t) Cl= 1.14+0.382 In(D)-0.00008477a-0.139 In(RH)+0.0000664RH2 Cs=0.440-0.0224 In(D)-0.193 In(T)+0.0000464T2-0.00000771RH2

• Journal of Biosystems Engineering
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• 제6권2호
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• pp.58-64
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• 1982

1. 생탈곡(生脫穀)벼의 관행(慣行) 평건(平乾)의 건조특성(乾燥特性)과 각종건조(各種乾燥) 환경이 건조속도(乾燥速度)와 동할미(胴割米)의 발생(發生)에 미치는 영향을 수원 264와 미네히까리 2개(個)의 품종(品種)에 대(對)하여 조사(調査)하였다. 2. 생탈곡(生脫穀)벼 야외(野外) 건조시(乾操時) 벼의 水分含量(수분함량)은 주(主)로 조사(照射)된 누계일사량(累計日射量)에 따라 결정되었으며 건조(乾燥) 시기(初期) 벼의 수분함량(水分含量)과 일사량(日射量)과의 관계를 수식화(數式化)하였다. 3. 생탈곡(生脫較)벼 건조특성(乾燥特性)은 대체적으로 항율건조특성(恒率乾燥特性)을 따랐으며 벼층(層)의 두께가 클수록 항율건조(恒率乾燥)에 따르는 경향이 더욱 뚜렷하였다. 4. 벼층(層)의 두께와 건조속도(乾操速度)와의 관계는 지수적(指數的)인 수식(數式)으로 나타낼 수 있었다. 5. 건조기간중(乾燥期癎中) 환적효과(換積效果)는 건조속도(乾操速度)의 면(面)에서는 벼층(層)두께의 감소(減少)에 상당하는 효과(效果)를 보였으며 동할미(胴割米) 발생율(發生率)을 현격히 줄이는 효과(效果)를 나타냈으며 수원(水原) 264와 같은 장위종(長粒種)에서 그 효과(效果)는 더욱 뚜렷하였다. 6. 생탈곡(生脫穀)벼의 건조장소(乾燥場所) 간(間)에는 뚜렷한 차이(差異)는 없었으며 일사량(日射量) 기준(基準) 벼의 건조효율(乾燥效率), 건조속도(乾燥速度) 및 동할미(胴割米)등을 고려(考慮)할 때 최적(最適) 벼층(層)의 두께는 6cm정도(程度)이었다.

• 한국식품저장유통학회지
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• 제4권3호
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• pp.279-286
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• 1997

The effect of drying temperature (30, 40, 50, 60$^{\circ}C$) on chemical components of Shiitake mushroom(Lentinus edodss) was investigate. When compared proximate composition on pileus and stipe of raw and dried materials, all of them were found to be higher in the stipe part than in the pileus part. The major components of organic acid were oxalic, citric, malic, malonic and pyroglutaric acid. The contents of free and total amino acids in pileus and stipe were 3458.4, 7640.2mg% for pilueus; 2298.0, 6171.5mg% for stipe on dry basis, respectively. On the other hand, there was no significant difference in the changes of crude ash and organic acids content of Shiitake mushroom among drying temperatures. But the amount of crude fats was increased and that of reducing sugars was decreased with increase of drying temperature. The contents of crude proteins of pileus part of dried materials were increased with increased drying temperature, but those of stile part were gradually decreased. The contents of free amino acids decreased with increase in drying temperature, but those of total amino acids were gradually increased.

• 한국조경학회지
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• 제34권2호
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• pp.36-43
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• 2006

This study was carried out to determine the ways in which drying improves and develops dredged soils which exist widely in the lowlands of Korea. Before drying there were large variations in the fundamental physico-chemical properties of dredged soils collected from different places. In the sample soils, saturated hydraulic conductivity decreased gradually with an increase in bulk density with the exception that in air-dried soils a reverse trend was observed. Also in the sample soils, the sedimentation volume and the consistency limits decreased gradually with the decrease in soil water content after the air-drying treatment. The porosity of the sample soils decreased from $0.67{\sim}0.87m^3/m^3\;to\;0.58{\sim}0.66m^3/m^3$ and the liquid-phase range decreased from $0.41{\sim}0.83m^3/m^3\;to\;0.29{\sim}0.71m^3/m^3$. The solid-phase range of sample soils increased $0.13{\sim}0.33m^3/m^3\;to\;0.24{\sim}0.37m^3/m^3$ same as above with air-drying treatment. In conclusion the air-drying treatment caused an irreversible effect on some physical properties. Accordingly, these facts indicate that the effects of air-drying treatment on these properties are considered to be resulted from irreversible changes in the structural status of the sample soils.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.413-422
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• 2000

Samples of banana were dried in a two-stage heat pump dryer capable of producing stepwise control of the inlet drying air temperature while keeping absolute humidity constant. Two stepwise air temperature profiles were tested. The incremental temperature step change in temperature of the drying air about the mean air temperature of 30 $^{\circ}C$ was 5 $^{\circ}C$. The total drying time for each temperature-time profile was about 300 minutes. The drying kinetics and color change of the products dried under these stepwise variation of the inlet air temperature were measured and compared with constant air temperature drying. The stepwise air temperature variation was found to yield better quality product in terms of color of the dried product. Further, it was found that by employing a step-down temperature profile, it was possible to reduce the drying time to reach the desired moisture content.

• Journal of the Korean Wood Science and Technology
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• 제36권5호
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• pp.49-55
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• 2008

This study was carried to investigate the effects of steaming and four different drying methods on the longitudinal liquid permeability of Korean pine (Pinus koraiensis Sieb.et Zucc.) board. Four drying methods were air drying, conventional kiln drying, microwave-vacuum drying and high temperature drying. Darcy equation was used for calculating the specific permeability of the small sapwood specimens taken from the treated boards while capillary rising method was used for the heartwood specimens. The sapwood specimens were extracted with water and benzene-alcohol solution to examine the mechanism of liquid flow in treated wood. No significant correlation was found between specific permeability and the number of resin canals of the sapwood specimens. Extraction decreased the differences of specific permeabilities of the sapwood specimens between the five treatment methods. The effects of extraction on the longitudinal permeability are different between five treatments. The fluid path in heartwood was observed by dynamic observation method.

• 설비공학논문집
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• 제21권1호
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• pp.1-8
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• 2009

The simulation of a heat pump dryer has been carried out to figure out the effect of air flow rate on the drying performance represented by MER, SMER, and so on. The simulation includes the analyses of one-stage heat pump cycle and simple drying process using the drying efficiency. The heat pump cycle with Refrigerant 134a has been considered. In the dryer, some of drying air from the drying chamber flows through the heat pump system, the rest of air bypasses the heat pump system. The two air flows joins before the drying chamber inlet. The performance parameters considered in the present study are MER, SMER, the temperature and humidity of drying air. Those parameters are compared for different total air flow rate or bypass air flow rate.

• 한국축산식품학회지
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• 제42권1호
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• pp.98-110
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• 2022

Meat jerky is a type of meat snack with a long shelf life, light weight, and unique sensory properties. However, meat jerky requires a long manufacturing time, resulting in high energy consumption. In this study, beef jerky was prepared by injecting different concentrations of brine at different hot-air drying times (0-800 min). When the brine injection levels were increased to 30%, the drying characteristics of beef jerky, such as drying time and effective moisture diffusivity, were significantly improved owing to the relatively high water content and the formation of porous structures. The physicochemical properties (e.g. meat color, porosity, shear force, and volatile basic nitrogen) of the beef jerky injected with 30% brine were improved owing to the shortened drying time. Scanning electron microscopy images showed that the beef jerky structure became porous and irregular during the brine injection process. Our novel processing technique for manufacturing beef jerky leads to improved quality characteristics and shortened drying times.

• 한국지열·수열에너지학회논문집
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• 제11권4호
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• pp.1-6
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• 2015

In this study, energy performance of two types of food dryers which are electric heater and heat pump is studied experimentally. With drying chamber temperatures controlled at 45, 50 and $55^{\circ}C$, sliced radish is dried from an initial mass of 90 to final 7 kg. Moisture content, drying time, total power consumption, MER (moisture extraction rate, kg/h) and SMER (specific moisture extraction rate, kg/kWh) are measured and analyzed. As the drying chamber temperature is increased, drying time is shortened but energy efficiency is reduced for both types. For an electric heater dryer, the effect of chamber temperature on drying time is significant but less significant on energy efficiency. For a heat pump dryer, the dependence of chamber temperature on drying time is weak but strong on energy efficiency. Temperature levels have little effect on electric heater dryer performance but strong effect on heat pump dryer which operates on a vapor compression refrigeration cycle. The energy performance of the heat pump dryer is superior with an average SMER of 2.175 kg/kWh which is 2.22 times greater than that of the electric heater dryer with SMER of 1.224 kg/kWh.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.95-101
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• 2022

Due to the pandemic caused by COVID-19, the demand for face masks is soaring and has often caused a shortage. The aim of this study was to evaluate the effect of ultraviolet (UV) and drying treatments on microbial contaminants in facial masks. To conduct this study, standard procedures were designed to develop samples contaminated by the control bacteria Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The contamination level of the standard samples was approximately 6.30 × 10⁶ CFU/ml, and the UV light treatment was performed 1, 3, 5, and 7 times. To evaluate the effect of the UV and drying treatments, the masks were first treated with UV 1, 2, and 3 times, followed by the drying process. As a result, the mask contaminated with E. coli and P. aeruginosa showed a bacterial rate of approximately 99.9% after 1 UV irradiation, and in the case of the S. aureus-contaminated mask, it exhibited a bactericidal rate of approximately 99.9% after 7 UV irradiations. However, when the drying process was included after UV irradiation, all the samples contaminated with E. coli, S. aureus, and P. aeruginosa showed a bactericidal rate of 99.9% or more. The results of this study suggest that UV and drying treatments can effectively reduce the bacterial contaminants in facial masks. In addition, these results provide fundamental data and appropriate sterilization methods for reusing masks.