• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.167-167
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• 1982

Italian poplar (Populus euramericana) rotary veneers were press-dried and air-dried to study drying curves, thickness shrinkage and width shrinkage of them under several drying conditions such as drying temperatures and veneer thicknesses. The results of the study are summarized as follows; 1. In press-drying, drying times from green condition to about final moisture content of 10 percent with veneer thickness of 0.6mm by platen temperatures required about 10 minutes at platen temperature of $100^{\circ}C$, 3 minutes at $110^{\circ}C$, 1 minute at $120^{\circ}C$ and $130^{\circ}C$, respectively. 2. In press, drying, drying times from green condition to about final moisture content of 10 percent by veneer thicknesses required 2 minutes at veneer thickness of 0.6mm, 4 minutes at 1.2mm,6 minutes at 1.8mm and 9 minutes at 3.6mm, respectively. 3. In air-drying, drying times from green condition to air-dried moisture content by veneer thicknesses required 15 hours at veneer thickness of 0.6mm, 18 hours at 1.2mm and 23 hours at 2.4mm, respectively. 4. Thickness shrinkage of press-drying was remarkably greater than that of air-drying, but width shrinkage of press-drying was rather smaller. 5. Difference of thickness shrinkage among platen temperatures was insignificant, and width shrinkage at platen temperature of $130^{\circ}C$ was the least.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.453-459
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• 1996

This study was carried out to determine the changes in quality during the drying process and the optimum drying condition for utilizing soybean curd residue. The quality criteria for soybean curd residue were acid value, peroxide value, fatty acid composition and microbial concentration. The acid values of soybean curd residue were 7.5, 4.5 and 5.9 KOH mg/g upon 12 hour drying with open-air sun, ambient-air blast and warm-air blast, respectively. The numbers of total aerobic bacteria and molds increased remarkably during drying with open-air sunlight, ambient-air blast and warm-air blast except for hot air blast. Among different drying methods, the hot air blast drying(1kg of sample) was the most effective methods, which completed in three hours. Also, the drying method demonstrated a typical drying curve ; settling down, constant rate drying and falling rate drying period were shown within one hour, from one and three hours and after three hours, respectively. Moreover, there was significant variation in the constant drying period for the quality of soybean curd residue.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.71-77
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• 2004

Drying Shrinkage has much complexity as it has relations with both internal elements of concrete and external factors. Therefore, experiments on Concrete Drying Shrinkage are carried out in this study under simplified circumstances applying temperature & Humidity test chamber which enables constant temperature and humidity. Comparative analyses have been made respectively according to the consequences aiming at modelling for prediction of Concrete Drying Shrinkage and making out measures to reduce it. Strain Rate of Drying Shrinkage of concrete under the condition of dry air appears to rise by about 20%-30% in proportion as the temperature rises $5^{\circ}C$ when the humidity was held below 10% compared under the condition of dry temperature & Humidity test chamber. Strain Rate of Drying Shrinkage in pit sand concrete increased 20% higher than measured when in river sand under the condition of 90-day material age. A general formula with two variables is derived as follow ${\varepsilon}={\alpha}_1＋{\beta}_1x_1＋{\beta}_2x_2＋{\beta}_3x_1^2＋{\beta}_5x_2^2$. and also graphed in 3 dimensions, enabling to apply to actual design and predict Strain Rate of Drying Shrinkage in concrete. The results of prediction of Rate of Drying Shrinkage by Response Surface Analysis are as follows. The coefficient of correlation of Drying Shrinkage in Concrete was over 90%.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.10-17
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• 2002

This study was carried out to investigate a heat treatment condition and suitable drying schedule of bamboo material(Phyllostachys nigra var. henonis) for a vertical flute with small-notched bamboo. It is very important to prevent drying defects during its drying process. We investigated the effort of heat treatment the most suitable drying schedule for small-notched bamboo vertical flute without drying defects in this research. A direct heat treatment method and drying conditions of 3($20^{\circ}C$ 65%, $40^{\circ}C$ 40%, and dry at air condition) were applied to the Bamboo specimen that felled in several areas for a month. The result suggested that the most suitable drying schedule with the less split and the shortest time was to dry at $40^{\circ}C$, 40% condition and it was useful to direct heat-treatment because of reducing the number and size of split during drying bamboo.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.277-280
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• 2003

Material, mix proportion, curing condition, temperature, humidity and wind velocity have an influence on drying shrinkage of concrete. In this paper, to evaluate the effect of curing condition at early age on the drying shrinkage of concrete was investigated varying curing age for different binder. The principal conclusions from this research were as follows: 1) In case of 14 days of water curing, the drying shrinkage of concrete is smaller than 7 days of water curing, independence of type of binder. 2) In case of 4 days of water curing, the ratio of increase of drying shrinkage of concrete using fly-ash and slag powder is more remarkable than using portland cement alone, comparing the drying shrinkage of 7 days of water curing.

• Journal of the Korean Wood Science and Technology
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• v.18 no.1
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• pp.39-51
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• 1990

This research was carried out to offer the basis data for development of optimum drying schedule for a domestic oak species (Quercus grosseserrata B1.) by investigating drying rate. stress, defect, and moisuture gradient with board thicknesses and drying schedules (code number T4-C2 and T3-B1). The results were obtained as follows: 1. Average drying rate and total drying time from 52.2% to 5.8% were 0.105%/hr and 486 hours for drying schedule T4-C2 and those from 62.1% to 8.3% were 0.070%/hr. and 811 hours for drying schedule T3-B1. 2. Drying rates for 28mm- and 31mm-thick boards showed similar tendency, but were significantly different from 25mm- thick board in drying schedule T4-C2 and those for 22mm-, 25mm- 28mm- and 31mm-thick boards showed similar tendency but were significantly different from 19mm- thick boards in drying schedule T3-B1. 3. The moisture gradients for drying schedule T4-C2 were steeper than those for drying schedule T3-B1 during drying period. and especially in early drying stage slow slope of moisture gradients of drying schedule T3-B1 was effective in preventing serious problem of surface checks. 4. Drying stresses were lower in drying schedule T3-B1 than in drying schedule T4-C2 during drying period. 5. Drying schedule T4-C2 was appropriate for 25mm-thick board but not for 28mm- and 31mm-thick board because of strong drying condition. Drying schedule T3-B1 was appropriate for 28mm- and 31 mm-thick board but not for 19mm-, 22mm-, and 25mm-thick board because of weak drying condition.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.981-992
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• 2004

Freeze drying under vacuum condition is a complex process that involves simultaneous heat and mass transfer, sublimation of ice, and motion of sublimation front. Proper treatment of the motion of sublimation interface is crucial for an accurate prediction of the freeze drying process. Based on the enthalpy formulation that has been successfully used in liquid/solid phase change problems. a fixed grid method. streamlined for the freeze drying analysis. was developed in this study. The accuracy of the fixed grid method was checked by solving a one-dimensional tray freeze drying and a two-dimensional vial freeze drying problem and then comparing the results with those by the moving grid method. Finally. the freeze drying characteristics of two-dimensional slab and axis-symmetric cylinder was investigated using the fixed grid method.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.501-505
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• 2003

SrZrO$_3$ resistive oxides on Ag tapes were prepared by the sol-gel and dip coating method to investigate the effect of PVP content and drying condition on microstructure of the films. Although the film thickness increased with the addition of PVP, the amount of PVP and heat treatment were not effective to reduction of formation of microcracks at the films. However, lower drying temperature and longer drying time were beneficial to control the microcracks of the SrZrO$_3$ films, indicating that the microcracking of the films was governed primarily by the drying condition.

• Journal of Biosystems Engineering
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• v.16 no.1
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• pp.60-82
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• 1991

Drying process of red pepper is very important in terms of drying cost and quality of the end product. Recently, many studies on red pepper drying have been performed. Nevertheless, an optimum drying condition is not established yet. Drying characteristics of red pepper is much affected by drying factors such as variety and initial state of red pepper as well as by environmental drying factors such as temperature and relative humidity of drying air. Various varieties of red pepper are being cultivated and the initial state of red pepper at harvest is very ambiguous. For this reason, it is very costly and time-consuming to establish an optimum drying condition of red pepper by experiment. A general drying model to descirbe a drying process has not been developed due to diversity of drying characteristics of red pepper. This study was, therefore, performed to develop a general drying model describing a drying process of red pepper. The results from this study are summarized as follows. 1. A basic model was established to develop an appropriate mositure content model and temperature model describing a drying process of red pepper, and the basic model was validated with experimental data. 2. The bone dry weight of fruit and mositure content were accepted satisfactorily as parameter to define the arbitrary red pepper. 3. The equilibrium moisture content of red pepper was found out to be different according to the variety of red pepper, air temperature and relative humidity. Also, the EMC model was developed using the parameters of air temperature, relative humidity and bone dry weight of fruit. 4. A general drying model for red pepper was developed, parameters of which were expressed as the function of drying factors related with drying phenomena. The developed drying model was found out to describe well the drying process of red pepper.

• Journal of computational fluids engineering
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• v.16 no.2
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• pp.75-80
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• 2011

In this study, three-dimensional transient numerical simulations were carried out for a paint drying system of vehicle. The vehicle on assembly line passes through the drying system consisting of hot and cool air blow region. For the moving motion of the vehicle, moving of inlet boundary condition and MRF technique are used. The transient distribution of temperature and velocity in the drying system were predicted numerically. In order to validate the numerical results, transient distribution of the vehicle surface temperature was compared with experimental data, showing a good agreement. As a result of present study, optimal operating condition of the drying system are to be suggested.