• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.373-384
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• 2009

For the first step on the quantitative evaluation of shrinkage reduction and differential shrinkage analysis of lightweight aggregate concrete, this study sets the moisture transport model of concrete by pre-absorbed water of porous lightweight aggregates and measured effective moisture diffusion coefficient, moisture capacity, degree of humidity supply and degree of humidity consumption by water binder ratio and aggregate type. The effective moisture diffusion coefficient in steady state caused by humidity difference between inside and outside of concrete had low value as low water-binder ratio. And in case of same water-binder ratio, effective moisture diffusion of mixtures used normal aggregates were lower than those used lightweight aggregates. To determine moisture store capability of concrete - moisture capacity, moisture contents were measured in 9 humidity conditions. As a result moisture contents of mixtures used lightweight aggregates was higher than mixtures used normal aggregates in all humidity conditions. This study measured lightweight aggregates' degree of humidity supply that applicable to normal atmospheric environment (above RH 50%) and made it quantitatively. Also amount of moisture release was set as a exponential function that represents a clear trend proportion to time and inverse proportion to humidity of the surroundings. As the result of measurement about degree of moisture consumption inside concrete following the internal consumption caused by cement hydration self-drying, it was showed that rapid decrease of humidity, around 10%, at early ages (7~10 days) when water-binder ratio is 0.3 and slow decrease around 5% and 1% when water-binder ratio is 0.4 and 0.5.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.159-164
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• 2009

This study was carried out to elucidate changes in concentration of pesticide residues in Chinese matrimony vine and jujube during drying. Test pesticides, triadimefon and triforine for chinese matrimony vine and methoxyfenozide and thiacloprid for jujube, which are commonly used for the crops in Korea, were treated to the crops by spraying and dipping. The pesticide residues in both fresh and dried Chinese matrimony vine and jujube were analyzed by using a GLC-ECD and an HPLC-DAD. Processing factors of the pesticides in Chinese matrimony vine and jujube by drying ranged from 1.41 to 2.28 and from 1.50 to 4.20, respectively. And reduction factors of the pesticides in the crops ranged from 0.29 to 0.47 and from 0.68 to 0.98, respectively. These results indicate that concentrations of the pesticides in the test crops increased after drying, while amounts of pesticides in them were diminished by drying.

• Korean Journal of Remote Sensing
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• v.26 no.5
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• pp.497-510
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• 2010

In this study, comparisons of the backscattering coefficients and the coherence values which had been extracted from SAR (Synthetic Aperture Radar) images such as JERS-1, ENVISAT and ALOS satellites with surface roughness, surface geometric and soil moisture content were carried out. As the results of analysis using the backscattering coefficient and coherence values from SAR images, the coherence was shown high in the region containing more of mud fraction due to higher viscosity of fine grain-size. A lot of tidal channels were well developed in the Ganghwa tidal flat, affecting the drainage of seawater and subsequent soil moisture content by exposure time of tidal flat. The backscattering coefficient. consequently, appeared to be lower in sand flat and mix flat with decrease of soil moisture. In contrast, most mud flats were distributed at high elevation so that soil moisture was not much influenced by seawater. The backscattering coefficient in mud flat seemed to have a relationship with the density of tidal channel. In addition, lowering backscattering coefficients in the all Ganghwa tidal flat was observed when surface remnant water increased according to the amount of rainfall. The correlation between backscattering coefficient, coherence and sediment environment factors in the Ganghwa tidal flat was investigated. In the future, more quantitative spatial analysis will be helpful to well understand the sedimentary influence of various sediment environment factors.

• Composites Research
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• v.30 no.6
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• pp.422-428
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• 2017

The moisture absorption behavior, tensile properties, and thermal analysis properties of MWCNT embedded nanocomposites exposed to temperature and moisture were evaluated. The contents of MWCNT were 0 wt%, 1 wt%, and 2 wt%, respectively. The specimens were exposed to immersed conditions at $25^{\circ}C$ and $75^{\circ}C$ for up to 600 hours. According to the results, the apparent moisture content increased as the exposure time increased, but the difference between the maximum moisture content and the moisture content at 600 hours was almost constant. The tensile modulus decreased with increasing exposure time and the degree of decrease was increased significantly as the MWCNT content and exposure temperature increased. The tensile strength decreased with longer exposure time without MWCNT, but increased with MWCNT due to the reinforcing effect of MWCNT. The storage modulus, glass transition temperature, tan d peak magnitude were low as the exposure time increased, but tan d curves with two peaks appeared when exposed to high exposure temperature for more than 300 hours.

• Food Engineering Progress
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• v.21 no.2
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• pp.116-125
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• 2017

This study aims to make extruded rice snack with high quality in texture and nutrition by adding mealworm. Addition of the mealworm has the merit to fill in high-quality protein and unsaturated fatty acids which are insufficient in rice. Thus, the physicochemical properties were investigated through the process of extrusion cooking. As the extrusion process varied, the die temperatures were set to $120^{\circ}C$ and $130^{\circ}C$. Also, the moisture contents were adjusted to 30% and 35%. The specific length, the expansion ratio, and the water absorption index increased as the added content of mealworm became higher. On the contrary, the density, the breaking strength, the apparent elastic modulus, and the water solubility index decreased. As mealworm and moisture content increased, DPPH radical scavenging activity significantly increased but the rancidity decreased. As a result, the addition of mealworm to the extruded rice snack was effective in improving texture, nutrition, and antioxidation.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.249-255
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• 2009

In order to calculate the processing and reduction factor between fresh and dry Welsh onion which was widely used as a dried agricultural ingredient of food in Korea. 7 pesticides such as pyridalyl, kresoxim-methyl, spinosad, flufenoxuron, difenoconazole, metconazole, and tebufenozide were tested. After 2 sites field trial conducted and measured water contents by drying at $60^{\circ}C$ and analyzed the pesticide residue. Water contents of fresh and dried Welsh onion are 89.2 and 10.2% respectively. Averages of processing factor showed 7.24 of pyridalyl, 2.85 of kresoxim-methyl, 7.43 of spinosad, 3.17 of flufenoxuron, 4.38 of difenoconazole, 2.40 of metconazole and 8.13 of tebufenozide into 2 field samples. Averages of Reduction factor showed 0.87 of pyridalyl, 0.35 of kresoxim-methyl, 0.88 of spinosad, 0.38 of flufenoxuron, 0.52 of difenoconazole, 0.29 of metconazole and 0.98 of tebufenozide. Residual amounts of pesticides in/on fresh Welsh onion reduced during drying process.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.11
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• pp.107-120
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• 2000

무, 당근 및 감자를 대상으로 조리방법 (boiling, pressure cooking, microwave cooking)에 따른 dietary fiber 성분, 수분함량 및 조직감의 변화에 대하여 조사하였으며 조직감에 영향을 미치는 성분에 대해 연구해보았다. 시료내에 존재하는 pectin의 함량은 조리시 원료시료에 비해 현저하게 감소하였으며, microwave cooking>pressure cooking>boiling의 순서로 점차 감소하였다(P<0.05). ADF, NDF 및 Cellulose, Hemicellulose, Lignin은 boiling과 pressure cooking의 경우에는 원료시료에 비해 모든 성분이 증가현상을 나타내었으며, microwave cooking의 경우에는 감소하였다(P<0.01). Hemicellulose와 lignin은 조리에 의한 영향을 거의 받지 않는 것으로 나타났으며, cellulose는 조리 방법에 따라 상당한 영향을 받는 것으로 나타났다. 조리방법에 따른 수분함량의 변화는, boiling시에는 원료시료에 비해 현저한 증가를 보였으며, pressure cooking의 경우에는 조금 감소하였으나 뚜렷한 차이가 없었고, microwave cooking시에는 현저한 감소현상을 나타내었다(P<0.001). 조리 방법에 따른 조직감의 변화는 침투시험시에는 maximum force가 raw>microwave cooking>pressure cooking>boiling의 순서로 점차 감소하였으며, 절단 시험시에는 maximum force가 microwave cooking>pressure cooking>raw>boiling의 순서로 점차 감소하였다. 관능검사 결과, 견고성은 원료시료가 가장 컸으며, microwave cooking>pressure cooking>boiling한 시료의 순서로 점차 감소하였고 씹힘성은 microwave cooking방법으로 조리한 시료가 가장 컸으며, pressure cooking>raw>boiling의 순서로 점차 감소하였다. 기계적 측정 결과와 관능검사 결과를 연관시킨 결과, 높은 연관성이 있었다. 이러한 결과로부터 조리시 시료의 견고성은 pectin의 함량과 밀접한 관계가 있어서, 즉 pectin의 함량이 증가함에 따라 견고성이 증가되는 것을 알 수 있었고, 씹힘성은 수분함량과 밀접한 관련이 있어서, 즉 수분함량이 감소함에 따라 씹힘성이 증가되는 것을 알 수 있다. 이상과 같은 결과들은 무, 당근 및 감자에 있어서 모두 같은 경향을 나타내었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.824-830
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• 1996

In order to minimize the deterioration of osmotic dried apple quality, the characteristics of mass transfer during osmotic dehydration such as solid gain(SG), weight reduction(WR) and moisture loss(ML) were investigated. Moisture and solid transfer were analyzed by Fick's law. The highest (equation omitted)E value was observed with severe browning at $60^{\circ}C.$ The concentration effect on (equation omitted)E were higher at high temperatures than at low temperatures. SG, WR and ML increased as immersion temperature, sugar concentration and immersion time increased. Higher concentration of sucrose led to more sucrose absorption resulting increase in SG. Diffusion coefficients of moisture increased with immersion temperature and sugar concentration. As concentration increased, diffusion coefficients of solids increased at $20^{\circ}C$ while it decreased at $40^{\circ}C$ and $60^{\circ}C.$ Arrhenius equation was appropriately explain the effect of temperature on diffusion coefficients. Moisture and solid diffusion showed high activation energy in 20 。Brix solution, compared with in 40 and 60 。Brix.

• Food Science and Preservation
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• v.12 no.1
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• pp.54-61
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• 2005

The absorption characteristics and their physical properties of hot air, vacuum and freeze dried soybean curd powder were investigated. Absorption conditions were at 5, 15, and 25 t with $0.11\~0.93$ water activities. Equilibrium moisture content and the monolayer moisture content determined by prediction models showed highest value in the freeze dried soybean curd powder due to porous structure. Absorption energy decreased with increasing water activity was not affected by drying method. In the comparisons of the isothermal absorption models, Oswin model generally was the best fit model for isothermal adsorption of soybean curd powder.

• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.35-43
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• 2013

We analyzed the relationships between backscattering coefficients of wheat measured by COSMO-SkyMed SAR and biophysical measurements such as biomass, vegetation water content, and soil moisture over an entire wheat growth period. Backscattering coefficients increased until DOY 129 and then decreased along with fresh weight, dry weight, and vegetation water content. Correlation analysis between backscattering and wheat growth parameters revealed that backscatter correlated well with fresh weight (r=0.88), vegetation water content (r=0.87), and dry weight (r=0.80), while backscatter did not correlated with soil moisture (r=0.18). Prediction equations for estimation of wheat growth parameters from the backscattering coefficients were developed.