• 한국연초학회지
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• 제3권1호
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• pp.30-40
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• 1981

The moisture sorption and desorption isotherms of various tobaccos were obtained over a relative humidity range from 0 to 90% at $20^{\circ}C$ and $30^{\circ}C$. The hysteresis effect, constant and rate of moisture sorption and desorption, monomolecular-layer moisture content, and specific surface area were analyzed from the obtained data. The moisture sorption and desorption isotherms showed a different characteristics for different tobacco varieties. At a lower humidity range below 50% RH, Burley tobacco had higher moisture sorption and desorption figures than Hicks and Basma, while, at a higher humidity range above 50% RH, Hicks had higher values than the others. The hysteresis effect of tobacco were greater in an intermediate humidity range (40-70% RN), and Basma showed a greater effect than the others. The sorption and desorption constant (K) increased with temperature, but decreased with RH, and Burley tobacco had larger K values, while Hicks had smaller K values than others. The sorption and desorption rate of Burley tobacco were greater than the other tobaccos. The monomolecular-layer moisture was 27.8 and 51.4mg/g, and the specific surface was 101 and $186m^2/g$, for Basma and Burley, respectively.

• 한국연초학회지
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• 제26권1호
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• pp.43-49
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• 2004

This study was carried out to investigate moisture sorption and desorption characteristics followed by tobacco type. Experiments were performed at various temperature(5, 15, 25, 40 $^{\circ}C$) and relative humidity range (11～84 %) controlled by saturated salt solution. Regression equation was obtained to predict equilibrium moisture according to various relative humidity, temperature and tobacco types. The obtained regression equation showed high $R^2$(above 0.95) and predicted accurate equilibrium moisture. Equilibrium moisture contents declines in the following order when a relative humidity is 50 % or above: expanded stem, flue-cured, expanded tobacco, reconstituted tobacco, USA flue-cured, orient, burley. To maintain 13 % moisture of each tobacco type in the range of 5～40 $^{\circ}C$ it is recommendable to control relative humidity 49～56 % for expanded stem, 50～57 % for flue-cured, 54～61 % for USA flue-cured, 56～60 % for reconstituted tobacco, 57～62 % for expanded tobacco, 58～64 % for orient and 58～65 % for burley, respectively. It means that the relative humidity of each tobacco type should be differently controlled to maintain the same moisture under the same temperature. In the range of 5～25 $^{\circ}C$, the lower temperature showed the higher equilibrium moisture content.

• 대한기계학회논문집A
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• 제37권9호
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• pp.1151-1158
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• 2013

습기 수착 물성은 전자 패키징 장치의 신뢰성에 있어서 층간의 수증기 압력에 의해 공정과정 동안 발생되는 박리 불량의 고장 분석 및 최적의 재료 개발에 있어서 필수적이다. 본 논문에서는 온습도 모델에 따른 전자 패키징 재료의 온도 의존적인 흡습 및 탈습 물성을 변수화 하였고 이에 대한 온도 및 습도의 영향에 대해 고찰하였다. 변수화된 확산성에서 얻어진 확산 활성화 에너지는 등가의 습기 수착 수준을 위한 가속 수명 비율을 결정하고 신뢰 수명 평가에 요구되는 등가의 소요 시험 시간에 미치는 습기 확산성의 영향을 예측할 수 있게 한다. 신뢰성 시험 표준에서 평가된 유연 전자 모듈의 가속 수명비율을 예시하였다.

• Journal of Ginseng Research
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• 제6권1호
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• pp.30-37
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• 1982

This study was conducted to investigate the water vapor permeability of packaging film, Al- foil laminated paper, and sorption properties of dehydrated and powdered foods. The results are as fellows. 1. Absorption rate of each products was greately affeoted by physicochemical properties of foods rather than initial moisture contents of the products. 2. The absorption rate of each products were in the order of freeze dried coffee, spray dried coffee, freeze drie4 ginseng extract, spray dried ginseng extract, ginger tea, black tea, citrus juice Powder and ssang wha tea. 3. Most of the products such as freeze dried coffee, spray dried coffee, freeze dried ginseng extract, ginger tea and black tea have shorter than a month of shelf life. 4. The stability of the products were greatly affected by its desorption properties than the degree of desorption of moisture. 5. Water vapor permeability of packaging materials which are laminated Al-foil with polythylene and glassin paper were mainly affected of thickness of Al-foil and polyethylene.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.52-61
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• 1991

In this paper, the difference of the property of absorption and desorption for five species in semi-steady state are studied. The species used are listed in Table 1 and the dimension of specimen was $8\times8{\times}T$(Tangential direction)cm and tested in various conditions. A change of average moisture content with time were measured in each cycles. The results obtained are summarized as follows. When the relative humidity in air was maximum or minimum, the distribution of moisture In wood of all specimens were illustrated by exponential curves of decrease or increased from lace 10 center of wood. From the consideration of coefficient of decrease(C), the amount of moisture change of spruce was larger than the others. The pheonomenon was considered no relation to the specific gravity in air dry, but the wood structures. The velocity of the absorption and desorption for species decreased in the order spruce(Picea sitchensis) neodobam(Fagus crenata), solsong(Tsuga heterophylla), meranti(Shorea sp.) and kaesoo(Cercidiphyllum japoicum). In case of constant temperature and water vapor pressure is changed. the amount of absorbed moisture was larger than that of constant water vapor pressure and temperature vaned. In this fact, it is considered that the property of sorption of wood is strongly influenced by vapor pressure gradient than temperature gradient.

• 한국식품과학회지
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• 제22권5호
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• pp.530-532
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• 1990

옥수수의 장기저장을 위한 기초연구로서 건조옥수수 또는 침지옥수수를 $80^{\circ}C$에서 삶고 건조한 다음 이들 시료의 수분흡습성질을 저장온도 $25^{\circ}C$, 상대습도 23-97%에서 비교하였다. 건조옥수수는 상대습도 23% 이하에서, 침지옥수수는 33% 이하에서 탈습현상을 보였고, 상대습도 97%에서 건조옥수수는 192시간 후에, 삶은 옥수수는 288시간 후에 곰팡이가 발생되었다. 동일한 수분활성도에서 침지옥수수는 가장 높은 평형수분함량을 보였다. 단분자막층 수분함량과 흡습열은 침지옥수수의 경우가 가장 높았으며, 등온안정곡선으로부터 얻은 저장안정의 상대습도는 60-70%이었다.

• 한국식품영양과학회지
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• 제20권3호
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• pp.281-283
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• 1991

The effect of temperature on hysteresis of rough rice grown in Korea was investigated. The maximum hysteresis effect of Chucheongbyeo paddy rice at 5$^{\circ}C$ amounted to an average 1.7% moisure content. However, their values at $25^{\circ}C$ and 4$0^{\circ}C$ averaged 1.2% and 0.7% moisture, respectively. It may be suggested that the exteents of hysteresis are affected by the temperature of hysteresis are affected by the temperature of adsorption and desorption.

• 한국식품영양과학회지
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• 제18권4호
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• pp.398-402
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• 1989

우리나라 장려콩 2품종(장엽과 황금)을 대상으로 흡습 및 조리성질을 조사하였다. 시료콩을 상대습도 $33{\sim}86%$, 온도 $16^{\circ}C$에서 125시간 저장할 때 상대습도 33%와 44%에서는 탈습, 그 이상의 저장습도에서는 흡습현상을 보여주었다. 흡습속도는 저장시간에 따라 크게 감소하였으며, 그 절대값은 저장습도가 높을수록 컸었다. 저장시간과 흡습속도와의 관계는 흡습속도식 $log\frac{dw}{dt}=b\;logt+loga$(여기에서 w는 수분함량, t는 시간, b와 a는 상수)에 잘 적용되었으며, 식에서 구한 수분함량과 실측치는 일치 하였다. 한편 $106{\sim}121^{\circ}C$의 온도에서 증자후 최대절단력으로 조리도를 비교한 결과 증자온도의 상승에 따라 일정한 조리도에 도달하는 시간은 대수적으로 감소하였다. 일정한 조리도를 나타내는 온도-시간과의 관계로부터 구한 z-값은 장엽콩이 $13.3^{\circ}C$, 황금콩이 $12.8^{\circ}C$이었다.

• 한국식품과학회지
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• 제17권2호
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• pp.101-106
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• 1985

콩우유 비지를 acetone과 ethyl alcohol로 세척한뒤 $60^{\circ}C$에서 건조시킨 건조비지의 흡습특성(吸濕特性)과 건조비지를 밀가루에 혼합하였을때 수분함량과 수분활성도 간의 관계를 밝히고져 본 연구를 시행하였다. 건조비지는 상대습도(相對濕度)(RH)별(別)로 $20^{\circ}C$에서 저장중 평형 수분함량에 도달하기 전에 과흡습(過吸濕) 경향을 보였으며 저장중의 흡습농도(吸濕溫度)는 모든 RH에서 높은 상관계수를 갖는 log(dw/dt)=b log t+log a의 관계식으로 계산이 가능하였다. 또한 건조비지를 밀가루와 혼합하였을때 등온흡습곡선(等溫吸濕曲線)으로부터 얻어지는 수분함량(Mi)과 수분활성도(Aw)간의 관계는 Mi=b Aw+ a의 직선 관계식을 보여 주었다. 이 식(式)을 타연구자(他硏究者)들이 제안한 식(式)들과 비교할때 실측치(實測値)에 더 유사한 계산값을 보여 본 연구에서 제안한 식(式)이 건조 비지와 밀가루의 혼합물(混合物)에는 적합(適合)한 관계식이라 할 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.418-421
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• 2000

A model was developed to describe the microbial decontamination of diesel contaminated soil in a soil column. The biodegradation rate of diesel in nature depends on temperature and the pH of soil, availability of nutrients, oxygen and water. The soil moisture content is one of the essential factors because it characterizes the availability not only of water to microorganisms but also of oxygen and nutrient dissolved in soil. In this work, the rate of biodegradation was modeled by coupling Michaelis-Menten kinetics for the aqueous-phase solute with adsoption-desoption equation for diesel sorption and desorption from soil.