• 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.

• Applied Microscopy
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• v.50
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• pp.15.1-15.6
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• 2020

Sample preparation including dehydration and drying of samples is the most intricate part of scanning electron microscopy. Most current sample preparation protocols use critical-point drying with liquid carbon dioxide. Very few studies have reported samples that were dried using chemical reagents. In this study, we used hexamethyldisilazane, a chemical drying reagent, to prepare plant samples. As glandular trichomes are among the most fragile and sensitive surface structures found on plants, we used Millingtonia hortensis leaf samples as our study materials because they contain abundant glandular trichomes. The results obtained using this new method are identical to those produced via critical-point drying.

• Analytical Science and Technology
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• v.10 no.6
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• pp.418-426
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• 1997

Dewatered digested sewage sludge were heated with microwave and their drying characteristics were investigated on the effect of their surface area, shape, diameter and thickness. The drying characteristics of identical samples in a conventional drying oven were studied. In conventional drying, constant rate period was not found and moisture was evaporated with capillary action. Moisture in the sludge was a bound water and free water was not exist. In microwave drying, the falling rate period was divided into two zones. In falling rate drying period, moisture movement occured by diffusion. The evaporation surface area was a significant variable, the greater heating surface area promoted water removal rate over wide region of water content. Drying rate was slow and constant rate drying period was found in wide moisture content region with increasing diameter. Drying characteristics appeared differently in various shape. In microwave heating, first of all temperature of sludge center was increased and was the highest. Temperature in the constant rate drying period was remained constantly at $80{\sim}100^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.121-135
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• 2020

This study aims to evaluate applicability for the continuous drying process using saturated and superheated steam for large-square timber. During drying of the boxed heart square timber, changes in moisture content were examined through the slices of the surface, inner and core layers. The results showed that there was a large moisture content difference between the surface and inner layers during saturated steam drying and between the inner and core layers during superheated steam drying. However, despite the moisture content difference between the layers, no surface check occurred, and an internal check occurred only near the pith or juvenile parts of the wood. The maximum value of the drying stress of the dried larch boxed heart square timber, calculated from the elastic strain of the slice and the tangential elastic modulus of the larch, was 1.30 MPa. The tangential tensile strength of the larch was estimated at 5.21 MPa under temperature and moisture content conditions when drying stress was at a maximum. That is, in the continuous drying process, the saturated and superheated steam did not generate a check in the surface because the drying stress of the wood did not exceed the tangential tensile strength. In further studies, the superheated steam drying conditions will need to be relaxed to suppress the occurrence of internal checks. Such studies would make the continuous drying process using saturated and superheated steam available for the drying of large-square timber.

• Korean journal of food and cookery science
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• v.27 no.1
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• pp.75-84
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• 2011

The aim of this study was to develop a convenient brown sauce product with long shelf life that has similar taste and quality characteristics with sauce used in restaurants. Response surface analysis was carried out to optimize brown sauce. Extracted brown sauce powder was subjected to hot air drying, infrared drying, freeze drying, and spray drying to determine the appropriate drying method for brown sauce manufacturing. The optimum extraction conditions were set by superimposing and reading each reaction surface that satisfied all of the sensory characteristics such as color, smell, taste, concentration, and overall preference level in order to set the optimum conditions for brown sauce production. The optimum extraction conditions for brown sauce were determined to be heating time 30 min, gelatin addition quantity 9.00%, and tomato paste addition quantity 11.25%. Reliability test showed a similar value to the predicted scope when compared to the experimental value obtained under the same conditions as the predicted value according to RSM (response surface methodology), enabling verification of the derived regression formula. Product powder of ideal brown sauce by heating, infrared radiation, freezing, and spray drying and investigate result for functional tests of color, flavor, taste, viscosity, overall acceptability and show highly acceptability on powder by infrared rays and freeze-drying methods. Especially, infrared radiation method resulted in favorable color and flavor values while freeze-drying method produced good taste and viscosity values and high overall acceptability. Therefore, infrared radiation drying method and freeze-drying method to product powder.

• Journal of the Korean Society of Food Culture
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• v.18 no.5
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• pp.437-442
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• 2003

This study was conducted to confirm the effect of drying method on quality of popped rice for making salyeotgangjung(popped rice lump with malt syrup) in process of drying gelatinized rice. The drying were performed at dry oven or convection oven, at $30^{\circ}C,\;50^{\circ}C\;and\;105^{\circ}C$, respectively. There were not significant differences in the hardness of popped rice among the drying methods. The dry at $30^{\circ}C$ constant in dry oven showed higher popping rate, good external surface, uniformed and well developed internal cell size. The dry at $30^{\circ}C$ in convection oven and $50^{\circ}C$ constant temperature in dry oven showed low expansion and poor external surface, respectively. In conclusion, the drying at $30^{\circ}C$ in non-convection oven had the highest quality of popped rice for salyeotgangjung.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.61-66
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• 1993

24mm-thick specimens from three species of plantation-grown softwood were press dried under two platen pressures of 1.75kgf/$cm^2$ and 3.50kgf/$cm^2$ to obtain drying information regarding to drying rate, thickness shrinkage and drying defects. The influence of platen pressure on drying fare in range of moisture content (30 to 10 percent) increased for pitch pine and larch, but reduced for korean white pine at higher pressure. Thickness shrinkage was increased at the higher pressure, and estimated thickness shrinkage at final MC of 10 percent became unrealistically greater for specimens containing higher final moisture content under the great influence of compressive strain. The effects of pressure on the amount of surface checks and honeycombing were different from species used. These species should have applied lower temperature than 177$^{\circ}C$ in this study to reduce surface checks and honeycombing.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.1057-1063
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• 1996

Y2O3-CeO2-ZrO2 powders were prepared from water-soluble salts using a coprecipitation method. The forming process of oxide and the characteristics of the calcined powders treated in different drying conditions were investigated. The oxidation was occurred at the temperature of around 40$0^{\circ}C$ and the main crystallization of ZrO2 around $600^{\circ}C$. On calcination at $600^{\circ}C$ heating lamp-dried powders consisted of agglomerates of globular morphology with average agglomerate size of 2.27${\mu}{\textrm}{m}$ and specific surface area of 68.3m2/g and spray dried powders contained dense spheric particles with average agglomerate size of 1.35${\mu}{\textrm}{m}$ and specific surface area of 11.0m2/g which exhibited low agglomeration tendency. Removal of the water by a freeze-drying technique produced calcined powders containing flake-like secondary particle structures with wide agglomerate size distri-bution of 0.1-60${\mu}{\textrm}{m}$ and specific surface area of 24.5${\mu}{\textrm}{m}$. The 20 MPa-pressed density (36.8-41.4% T,D) of calcined powders did not nealy depend on drying methods whilst compaction ratio of calcined powders derived from freeze-drying was the highest ( 6.24) among three drying methods. On continuous heating up to 150$0^{\circ}C$ the sinterability of calcined powders derived from heating lamp-drying was superior to those derived from spray-and freeze-drying. The final sintered density of calcined powders was the highest (96% T,D at 150$0^{\circ}C$) in case of heating lamp-drying.

• Food Science and Preservation
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• v.10 no.4
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• pp.470-475
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• 2003

The response surface methodology was performed by central composite design for moisture content, titratable acidity, hunter's color value and organoleptic properties based on drying temperature and time of Citrus, to apply basic data to preparation of dried Citrus. Moisture content, b value and organoleptic color were affected by drying temperature ; That decreased with increase of drying temperature. Titratable acidity was affected by drying time. Organoleptic flavor and taste were affected by drying temperature and time. The optimum drying conditons for organoleptic taste were 67.56$^{\circ}C$ in drying temperature and 8.06 hr in drying time.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.51-58
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• 2020

As interest in lunar exploration increases, studies on lunar surface environment simulation including a lunar soil simulant are being conducted. One of the problems when creating a vacuum environment with lunar soil is that it takes long time to reach high vacuum due to outgas from the soil. Most of the outgas is water, and the time to reach high vacuum can be significantly reduced by a pretreatment process that removes moisture adhering to the surface of the lunar soil before putting soil into a vacuum chamber. The existing soil drying methods were examined to determine how these methods were effective to remove moisture from the lunar simulant soil. Drying experiments of lunar soil samples were carried out using a dry oven, a microwave oven, direct heating method and a vacuum oven, and the results of the drying experiment were presented. Drying soil at 110℃ using a dry oven and drying soil by a microwave oven were not enough to remove moisture, and vacuum oven drying method and direct heating drying method at more than 200℃ were effective in water removal.