• Journal of the Korean Wood Science and Technology
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• v.14 no.1
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• pp.45-54
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• 1986

A study was conducted to determine the physical properties related to drying characteristics, the seasonal air drying curves and the kiln drying schedule for taun lumber imported and utilized. This kiln drying schedule was found by oven drying and developed by pilot testing of green lumber and partially air dried lumber. The results of this study were as follows; 1. Average green specific gravity and standard deviation of heartwood lumber were 0.60${\pm}$0.03 and those of sapwood lumber were 0.64${\pm}$0.02. 2. Radial shrinkage from green to air dry and from green to oven dry were 3.05 percent and 5.96 percent respectively, and tangential shrinkage from green to air dry and to oven dry were 5.49 percent and 8.74 percent respectively. 3. Drying time for 25mm thick green lumber (50 percent moisture content) air dried to 30 percent moisture content were 14 days in springtime. 6 days in summertime, and 12 days in autumntime, whereas for 50mm thick lumber in 36 days in springtime, 18 days in summertime, 38 days in autumntime. 4. Kiln drying schedules developed by oven drying were T8-B3 for 25mm thick lumber and T5-B2 for 50mm thick lumber. 5. Kiln drying curves of green 25mm and 50mm thick lumber were similar to those of partially air dried lumber from the level of 30 percent average moisture content. Green 25mm thick lumber (55.7 percent moisture content) was dried to 9.3 percent moisture content in 101.5 hours and green 50mm thick lumber (65.6 percent moisture content) was dried to 11.5 percent moisture content in 526 hours. 6. End checking for green 25mm thick lumber occured in 49.6 percent moisture content and reached maximum amount in 27.6 percent moisture content and closed in 15.8 percent moisture content. 7. End checking for green 50mm thick lumber and partially air dried lumber developed and reached maximum amount earlier then for 25mm thick lumber. 8. Final moisture content of surface layer for 50mm thick lumber was one half of that of core, and moisture content equalized in the lumber after nine days of room conditioning. 9. Casehardening for 50mm thick lumber was slight and was conditioned after nine days of room stroage. 10. Drying defects, such as end checking and surface checking, were not observed and the quality of dry lumber was first.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.538-545
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• 2017

Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. The equilibrium properties of moisture are described by means of water vapor sorption isotherms, which illustrate the hysteretical behavior of materials. In this paper, the prediction method of the moisture distribution inside the concrete members at fire is presented. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member. And the moisture diffusivity model of high strength concrete by high temperature is proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test result of other researcher. The proposed algorithm shows a good agreement with the experimental results including the vaporization effect inside the concrete.

• Fire Science and Engineering
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• v.23 no.5
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• pp.17-23
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• 2009

Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. The equilibrium properties of moisture are described by means of water vapor sorption isotherms, which illustrate the hysteretical behavior of materials. In this paper, the prediction method of the moisture distribution inside the concrete members at fire is presented. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member. And the moisture diffusivity model of high strength concrete by high temperature is proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test result of other researcher. The proposed algorithm shows a good agreement with the experimental results including the vaporization effect inside the concrete.

• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.127-134
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• 1992

Generally speaking, the internal moisture of concrete is mainly distributed in inner part and concrete surface which is exposed are dned according to influence of temperature and humidity. So, the properties which are compressive strength, modular elasticity, and volume change are different at each part even in same concrete. This is because moisture distribution is changed according to the evaporation and move ment of moisture, exist in the inner porosity of concrete. Therefore, it is necessary that we investigate the properties of concrete according to moisture distribution. The purpose of this study is investigating correlation between the moisture content and mechanical properties in concrete. Compressive and tenslle strength decrease according to increasing moisture content, but modular elas ticity increase. Those increasing or decreasing ratio at drying ratio 100% (absolute dries) is as follows in comparative of drying ratio 0 % (saturated condition).tion).

• Preventive Nutrition and Food Science
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• v.6 no.3
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• pp.163-169
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• 2001

To produce expanded, minimally hard extrudates from blends of raw pork meat (20%), defatted soy flour (25%), and corn starch using a single-screw extruder, various combinations of feed moisture, process temperature, and screw speed were evaluated. First series of extrusion runs were conducted according to a central composite rotatable design/response surface methodology (RSM). Upon assessing the full model for each response, insignificant terms were eliminated to determine final response surface models. Screw speed within the range evaluated was found to have no significant effect on expansion ratio (ER) or shear force (SF) of extrudates. Since examinations of the response surfaces and their generated grids of predicted values indicated that maximum ER and minimum SF were likely to be attained with a moisture-temperature combination outside the RSM experimental range, the second series of extrusion runs were conducted with several selected combinations of moisture and temperature to determine a practical optimum extrusion condition. The combination of 22.78% feed moisture, 16$0^{\circ}C$ process temperature, and 170 rpm screw speed was chosen as such a condition, and used in the final extrusion. The final product required less force to break than did commercial pretzel sticks.

• Journal of Biosystems Engineering
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• v.33 no.2
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• pp.101-105
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• 2008

Some physical properties of rapeseed such as geometric properties (linear dimensions, sphericity, seed volume, surface area) and gravimetric properties (the mass of one thousand seeds, bulk density) were analyzed at five levels of moisture content of 10.03, 14.91, 20.07, 25.06 and 30.12% (w.b.). The physical properties of rapeseed were evaluated as a function of seed moisture content. In the moisture range, when the moisture content increase, sphericity decreased from 0.946 to 0.927, and geometric mean diameter, seed volume and surface area increased from 2.17 to 2.31 mm, 5.58 to $6.88 \;mm^3$ and 14.76 to $16.77\;mm^2$ respectively. Mass of one thousand seeds increased from 5.04 to 6.46 g. Bulk density decreased from 579.3 to $549.2\;kg/m^3$ due to swelling of the seed.

• Restorative Dentistry and Endodontics
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• v.37 no.3
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• pp.155-159
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• 2012

Objectives: To investigate the effect of dentin moisture degree and air-drying time on dentin-bond strength of two different one-step self-etching adhesive systems. Materials and Methods: Twenty-four human third molars were used for microtensile bond strength testing of G-Bond and Clearfil $S^3$ Bond. The dentin surface was either blot-dried or air-dried before applying these adhesive agents. After application of the adhesive agent, three different air drying times were evaluated: 1, 5, and 10 sec. Composite resin was build up to 4 mm thickness and light cured for 40 sec with 2 separate layers. Then the tooth was sectioned and trimmed to measure the microtensile bond strength using a universal testing machine. The measured bond strengths were analyzed with three-way ANOVA and regression analysis was done (p = 0.05). Results: All three factors, materials, dentin wetness and air drying time, showed significant effect on the microtensile bond strength. Clearfil $S^3$ Bond, dry dentin surface and 10 sec air drying time showed higher bond strength. Conclusions: Within the limitation of this experiment, air drying time after the application of the one-step self-etching adhesive agent was the most significant factor affecting the bond strength, followed by the material difference and dentin moisture before applying the adhesive agent.

• Food Science and Preservation
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• v.8 no.3
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• pp.313-319
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• 2001

In order to produce the high quality rehydrated acorn Mook(Korean tradition gel flood) that enhance acceptability, the optimum condition was investigated for the rehydration process of dried Monk as salt concentration(0, 1, 2%), temperature(20, 70, 80, 90$^{\circ}C$) and time. The estimation of moisture gain, rehydration efficiency was analyzed statistically. The surface color md seniory evaluation were undertaken to evaluate the rehydrated Mook quality The optimum rehydration time was decided to 15 minutes and it takes 3 minutes for the cooling tilde. The moisture gain increased as the rehydration temperature increase. And the moisture gain and moisture gain rate were higher at 1% salt solution than other concentration. As the rehydration efficiency, surface color and sensory properties of rehydrated Mook, 1% salt treatment was superior.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.154-161
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• 2001

We have treated polyester fabric with $CF_4,\;C_2F_6,\;SF_6\;and\;C_3F_6$ glow discharge plasmas to develop functional fabrics which preserve moisture transportation and water proofing nature. Modified properties were evaluated by water vapor permeation rate and breakthrough water pressure. The change of surface morphology was observed by SEM. Fiber interstice of the plasma treated fabric was calculated as $0.32{\mu}{\textrm}{m}$, and this value was sufficiently ideal as water repellent material. The moisture transportation of ${CF_4}-treated$ fabric was good as much as untreated fabric, and those of $C_2$F(sub)6-treated, SF(sub)6-treated fabrics were reduced by 1~3%, and that of ${C_3F_6}-treated$ fabric was reduced by 15%. The best treatment condition were 0.06 torr 120 seconds in $CF_4$, 0.05 torr 30 seconds in $SF_6$, 0.08~0.15 torr 90 seconds in $SF_6$ and 0.1 torr 45 seconds in $C_3F_6$ respectively. The grade of moisture transportation effect was $CF_4>C_2F_6>SF_6>>C_3F_6$, and water proofing effect was $C_2F_6{\approx}CF_4>C_3F_6>SF_6$. It was observed by SEM that the thin film was formed on the surface of the treated substrate by the fluorocarbon plasma treatment.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.279-284
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• 2016

Assessing the handling properties of coal becomes a major issue for the operation of a fuel supply system in power plants, due to the increased types of coal imported into Korea. In this study, the cohesion strengths of 13 bituminous and sub-bituminous coals from different countries were tested by measuring the amount of force that leads to a failure of consolidated particles. The particle size was in the range of 0.1-2.8 mm, which represents the coarse particles before pulverization. While the cohesion strength was proportional to the compression force in the tested range, the effects of the surface moisture content and the weight fraction of fines were crucial for cohesive coals. At fixed conditions of surface moisture and particle size, large variations were found in the cohesion propensity between coals. For coals of 0.1-0.5 mm with the moisture added close to the critical value, cohesive coals had the density over $900kg/m^3$ after consolidation. The cohesion propensity was not correlated with the basic properties of coals with sufficient statistical significance.