• Journal of Biosystems Engineering
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• v.23 no.6
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• pp.583-590
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• 1998

This study was performed to determine the kinetic friction coefficient bulk density, dynamic and static angle of repose, and terminal velocity of the chopped rice straw in the moisture range of 8~23%, which could be used for better design and operation of the processing machinery and handling facilities. Friction coefficient was determined from the horizontal traction force measured by pulling the container holding the mass of rice straw on the various plate materials. Bulk density was measured with an apparatus consisting of a filling funnel and a receiving vessel. Dynamic angle of repose was calculated from the photos of bulk samples piled by gravity flow on a circular platform. Static angle of repose was determined by measuring the side angle of the bulk material which was left in the cylindrical container after natural discharge of the bulk sample through a circular hole in the bottom plate. Kinetic friction coefficients of rice straw on the PVC, mild steel, stainless steel, and galvanized steel were in the range of 0.303~0.434, 0.222~0.439, 0.204~0.448, and 0.206~0.407, respectively. and indicated linear increase with moisture content. The effects of moisture change on the friction coefficients were in the order of PVC, mild steel, galvanized steel, and stainless steel. Bulk density, dynamic and static angle of repose, and terminal velocity were in the range of 56.8~60.3 kg/m$^3$, 41.4~45.9$^{\circ}$, 94.4~100.8$^{\circ}$, and 1.07~4.48 m/s, respectively, and were increased linearly with the moisture content.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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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.

• Korean Journal of Food Science and Technology
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• v.19 no.3
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• pp.231-238
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• 1987

Two kinds of soy pastes with different colors (reddish brown and yellowish white) were dehydrated by freeze drying in powder form. Hygroscopic behaviors of powdered soy pastes were investigated under the conditions of various water acitivities (0.11-0.88) and three different temperatures (25,40 and $50^{\circ}C$), and presented a kinetic and thermodynamic interpretatons in the view point of qualities and storage stability. Moisture absorption isotherms of powdered soy pastes were of type II according with BET classification and can be described by the Henderson's empirical equation. The safe storage moisture levels calculated by the Laurie's equation were ranging from 5.5 to 3.98% dry basis with oaring temperatures. The moisture absorption process for powdered soy paste followed the Ist order kinetic in the difference of equilibrium moisture content and arbitrary moisture content and the initial step was characterized by very fast absorption of moisture. The change of, dispersion capacity and color difference for powdered soy paste were extremely dependent upon water activity under the storage and the maximum stability was found at safe storage moisture levels. Also, the variation of thermodynamic parameters with moisture content was significant at safe storage moisture content levels and suggested d the considerable correspondence to storage stability of powdered soy paste.

• Nuclear Engineering and Technology
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• v.33 no.1
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• pp.62-72
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• 2001

The one-dimensional finite element program was developed to analyze the coupled behavior of heat, moisture, and air transfer in unsaturated porous media. By using this program, the simulation results were compared with those from the laboratory infiltration tests under isothermal condition and temperature gradient condition, respectively. The discrepancy of water uptake was found in the upper region of a bentonite sample under isothermal condition between numerical simulation and laboratory experiment. This indicated that air pressure was built up in the bentonite sample which could retard the infiltration velocity of liquid. In order to consider the swelling phenomena of compacted bentonite which cause the discrepancy of the distribution of water content and temperature, swelling and shrinkage factors were incorporated into the finite element formulation. It was found that these factors could be effective to represent the moisture diffusivity and unsaturated hydraulic conductivity due to volume change of bentonite sample.

• Journal of Biosystems Engineering
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• v.11 no.1
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• pp.52-63
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• 1986

This study was performed to find out drying characteristics and develop drying model for the design of an efficient dryer or drying system of red peper. The basic model which describes drying phenomenon of red pepper was firstly established, and drying tests were conducted at 14-different drying conditions. In this test, the effects of drying air temperature and relative humidity on the rate of drying were undertaken. Finally, a new drying model based on these experimental results was developed to describe the drying characteristics of red pepper. The results from this study may be summarized as follows. 1. Drying constant of the basic model established from Lewis' experimental model and diffusion equation was theoretically deduced as a function of moisture content and inner-temperature of red pepper. 2. From the results of drying tests, drying air temperature was found to have the greatest effect on the rate of drying. However, the effect of temperature was small for the condition of high relative humidity, and for low temperature, the effect of relative humidity was found to be large even though the range of relative humidity was low. 3. Modified Henderson equation was found to be better than Chung equation as the EMC model for the estimation of the equilibrium moisture content of red Pepper. 4. Constant-rate drying period did not exist in the red pepper drying test. And falling-rate drying period was divided into three distinct phases. Drying rate was dependent on the moisture content, the inner-temperature of red pepper and the change of physical property due to drying. 5. Drying constant increased with decrease of free moisture content, but it decreased at the end of the drying period. Also, drying constant was dependent on the drying air temperature and relative humidity. 6. The new drying model developed in this study was found to be most suitable in describing the drying characteristics of red pepper. Therefore, it may be concluded that drying time could be accurately estimated by the new drying model.

• Journal of the Korean Society of Food Culture
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• v.22 no.1
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• pp.77-82
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• 2007

The general composition like moisture content, and the physical and sensory characteristics of the steamed rice cake added with powder of roots of balloonflowers were as follows. The moisture content in the roots was 4.13${\pm}$0.01%, crude protein 9.24${\pm}$0.11%, crude fat 3.07${\pm}$0.04%, crude fiber 33.82${\pm}$0.01%, and crude ash 8.16${\pm}$0.02%. The moisture content of the cake was decreased with increase of the root’s powder added. In physical characteristic, the hardness of the cake was increased with increase of the powder. The control cake was the highest in the cohesiveness. The springiness tended to be increased with increase of the powder. The gumminess was higher with increase of the powder, being 530.33% in the control and 284.44% in the sample with 12.0% powder added. The adhesiveness was decreased with increase of the powder. The color change was significantly decreased with increase of the powder. With increase of the powder, the value a was decreased, while the value b showed to be increased. In a sensory test, the favorite degree to color, flavor, bitter taste, moistness, soft-ness and overall acceptability was measured to get the follow result. To color, the lot with 6% of the balloonflower powder added showed the highest accept-ability with the same highest result also to flavor and bitter taste. The moistness and the softness were revealed as the highest at the control, and the chewiness was also highest at the lot with 3% of the powder added. The overall acceptability was highest as 5.75 at the lot with 6% of the powder added, coming out to be higher in order of the 3% added-lot, the control, the 9%-lot and the 12%-lot.

• Fashion & Textile Research Journal
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• v.10 no.3
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• pp.389-393
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• 2008

The purpose of this study is to provide beauticians with the fundamental material for them to use effectively heat permanent wave and satisfy their customers. It carried out an experiment with hair of a woman in her late twenties to investigate the change of physical and morphologic characteristics by its water content when performing heat permanent wave. It evaluated the water content as 0g, 1g, 2g, 3g and 4g respectively when performing the heat permanent wave on hair, then it compared and observed the wave type, tensile strength and elongation for its physical change also observed the morphologic change by scanning electronic microscope and transmission electronic microscope. The result of experiment on the physical specificity revealed that the wave was the most ideal when the water content was 2 g. The material with much water content made wave but the result was not satisfied. In the case of hair with water content of nearly 0g didn't make wave. In terms of tensile strength and elongation, the tensile strength was generally reduced as hair was damaged, on the contrary, the elongation was increased. It observed the change of morphologic characteristic and got the result that the damage on hair cuticle was deepen as its water content was decreased. It also showed the result that damage happened on hair cuticle more than hair cortex with the observation of fine structure on hair section by transmission electronic microscope. Generally chemical treatment damaged hair. Under consideration of this aspect, the ultimate goal of this thesis is to minimize the damage of hair caused by chemical treatment and get the satisfaction on the hair style. The result of experiment presented that the hair showed the best result when its water content was 2 g.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.6
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• pp.99-110
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• 1997

The study was conducted in order to investigate the basic geotechnical properties of sand-bentonite mixtures with the various bentonite contents. The results obtained are as follows : 1. Optimum moisture content of sand-bentonite mixtures was approximately 17.10~18.52% corresponding to the maximum dry density of 1.58~1 .64gf/$cm^3$. As the bentonite contents and curing peroid increased, both the maximum dry density and optimum moisture content of sand-bentonite mixtures increased. 2. The unconfined compressive strength of sand-bentonite mixtures increased as the increase of bentonite content, but it did not change along the curing period. 3. The sand-bentonite mixtures ruptured at 8~15% of the axial strain and the maxi-mum shearing stress was about O.7Okgf/$cm^2$. 4. According to the increase of bentonite content, the cohesion intercept and internal friction of the sand-bentonite mixtures increased slightly in the shear test, while the cohesion intercept increased largely, and the internal friction angle decreased largely in the triaxial test. 5. Both the initial void ratio and swelling of the sand-bentonite mixtures were very low with respect to the consolidation pressure increase. 6. The swelling and shrinkage of sand-bentonite mixtures increased slightly according to the increment of bentonite content.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.3
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• pp.222-228
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• 2000

The experiment was conducted to investigate the physico-chemical characteristics of vacuum and aerobically packed meat from Elk deer weighing 170 $\pm$ 10kg of 28 to 30 months old, chilled at 4$^{\circ}C$for 10days. The moisture content, crude protein, crude fat and crude ash in deer loin were 74.46%, 22.11%, 1.27% and 1.13%: the leg parts had 75.47%, 22.68%, 1.58% and 1.27%, respectively. The decrease in moisture content was greater in aerobic packaging than in vacuum packaging. The lysine content of loin and leg parts were 2,380mg% and 2,270mg% and the glutamate content of loin and leg parts were 4,145mg% and 3,987.5mg% respectively. On the whole, the loin contained more amino acids than leg part. Of the mineral contents, phosphorus, potassium and sodium were present in large amounts and mineral content was decreased with longer chilling period. The leg parts contained more potassium, sodium, phosphorus, zinc, magnesium and calcium than loin parts. In conclusion, vacuum packaging is considered more advantageous in preventing meat color change and microbial deterioration for consumers interest.

• Journal of the Korea Furniture Society
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• v.23 no.3
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• pp.324-331
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• 2012

The domestic pine was used to investigate the change of specific gravity, moisture contents, color and anatomical structure by accelerated weathering test (AWT). According to visual inspection, a few knot separation and looseness as well as considerable surface discoloration was found out. However, the crack and split of surface texture have been never occurred till the last step of AWT. On the whole, as the time of accelerated weathering test has increased, the specific gravity has decreased. Finally, after the 9th week of AWT, the specific gravity was 0.38 that reached to 82% compared to the control specimen. In case of moisture content (MC), it showed rising trend in its early stages, however, after 3th week of AWT it have displayed steady state. A deterioration of cell-wall components was not remarkably observed by scanning electron microscope (SEM), however the ray fractures of AWT specimen were observed more than those of control specimen. The full fracture of epithelial cell around resin canal was observed by optical microscope. The fracture of ray of 2th cycle AWT specimen was first, followed by 1th week and control group. A distortion of tracheid for early spring wood and fracture of epithelial cell were generally observed by a similar level, regardless of duration time of AWT. Therefore, it is obvious that increasing duration time of AWT does not affect the deterioration of micro-structure for wood members from this study. Although a considerable change of anatomical properties was not found, there is a need of further research to understand how will the changes of specific gravity and MC on the physical properties of wood member.