• Journal of Aquaculture
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• v.11 no.2
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• pp.183-191
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• 1998

To substitute fromzed and freeze-dried food for live food in the development of the artificial seedling production of bivalve larvae, the dietary value of live T. suecica was compared with those of freeze-dried T. suecica, frozed T. suecica, live T. suecica (50%)+frozen T. suecica (50%), and live T. suecica (50%)+freeze-dried T. suecica (50%) in the rearing of oyster (Crassotrea gigas) and hen clam (Mactra chinensis) larvae, and manila clam (Tapes philipninarum) spats. Oyster larvae fed live T. suecica showed the highest growth (shell hight $231.9^{\mu}$m) and survival rate (72.6%) and those fed freeze-dried T. suecica showed the lowest growth (shell height $168.9^{\mu}$m) and survival rate (35.3%). However, in the hen clam larvae, there were not significantly different among diet group in growth and survival rate. The small spats of manila clam fed live t. suecica or live T. suecica (50%)+freeze-dried T. suecica (50%) showed higher growth and survival rate than those fed other diet group. In the case of large spats of manila clam, live T. suecica and live T. suecica (50%)+frozen T. suecica (50%) showed better growht. But, survival rates were not different among diet groups. Dietary valuse of frozen and dried T. suecica were different on species and growth stage, and frozen and freeze-dried T. suecica can be partially used as substitute food for T. suecica live T. succica in shellfish hatchery.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.118-127
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• 2014

This study was investigated to compare the physicochemical properties between hot air dried ramie leaf (HR) and freeze dried ramie leaf (FR). There were no significant differences in moisture, crude protein, crude fat, crude ash, and carbohydrate content depending on the drying methods, but the dietary fiber content was significantly higher in FR than in HR. The major amino acids were aspartic acid, glutamic acid, and leucine, and the contents of total amino acids, total essential amino acids, and essential amino acid ratios were higher in FR compared with HR. Major fatty acids were linoleic acid, palmitic acid, arachidic acid, and linolenic acid. Hot air drying caused a decrease in unsaturated fatty acids and an increase in saturated acids; however, there was no significance difference between the two different drying methods. The contents of vitamin A, E, and C in FR were higher than those in HR, and there were significant differences in the contents of vitamin A and C depending on the drying methods. Regardless of the drying methods, both HR and FR were abundant in order of Ca, K, Mg, Mn, Fe, Na, and Zn. The contents of total minerals, total organic acids and total free sugars in HR were significantly higher than those in the FR.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.223-230
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• 1994

A practical study on a drying and fermentation system equipped with a stirring machine operated mechanically, of pig manure was conducted to prove the efficiency of and practicability to an ordinary pig farm. The type of the drying bed was a round-shaped (r=3m) concrete structure and the stirring machine was adopted to stir and transfer dried pig manure to the fermentation tank. The dried pig manure was put into a fermentation tank ($V=18m^3$), which was aerated from pipe lines installed at the bottom. While water content of pig manure passing through a drying bed was remarkably reduced than before drying, the drying efficiency of this system decreased in winter. However, the temperature of pig manure piled up in the fermentation room in winter reached over $60^{\circ}C$ and excess water of pig manure was removed during the fermentation process. The reduction rate of water content of pig manure, to which dried pig manure was added as bulking material on the drying bed, was 52.1%, but when dried without bulking material it was only 19.7%. Although the content of $P_2O_5$ of dried pig manure was slightly higher than that of fresh pig manure, progressive changes in chemical composition between fresh and dried pig manure made no great difference. Among the contents of minerals of fresh and dried pig manure, CaO was the highest and the rest were in the decreasing order of $K_2O$, MgO, and $Na_2O$. Population density of E. coli and Streptococci of dried pig manure was reduced by 142 and 236 times that of fresh pig manure, respectively. The installation cost of this drying and fermentation system was 4,185,630 won (approximately 5,232 US $) and operating cost per year was 190,000 won (237.5US $) on the basis of self-labor condition.

• 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.32 no.1
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• pp.52-58
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• 2004

Oak is one of major species in this country as well as pine, but has been less utilized because of its refractory properties. The purpose of this study is to develope an effective method for drying the boards and disks of Quercus variabilis. Among four end-coaters used in this study thick coating with polyvinyl acetate chrolide glue (PVAc) was proved as the most effective. The average air-drying rate of boards was 1.2%MC/day, which did not exceed the safe drying rate recommended by United States Department of Agriculture (USDA). The kiln drying schedule used in this study gave a good result in drying the air-dried boards to 8%MC without any internal checks. An attempt to prevent oak disks from V-cracking during air-drying using special pallet-type stickers was not successful.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.58.2-58.2
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• 2010

FPD (Flat Panel Display) 제조 공정에서 사용되는 패턴은 수 ${\mu}m$ 수준까지 감소하였으며, FPD의 크기는 급격하게 대형화 되여 현재 8세대(2200mm*2500mm)에 이르고 있다. 이에 따라, $1\;{\mu}m$ 이상의 크기를 갖는 오염입자에 의한 수율 저하를 극복하기 위한 세정효율의 향상 및 다량의 초순수 사용에 따른 폐수 발생으로 인한 환경오염, 또한 장비의 크기에 따른 공간 효용성 감소와 이에 따른 공정 비용의 증가 등의 어려움에 직면하고 있다. 따라서, 현장에서는 고효율, 저비용의 세정 공정 기술 개발에 대한 연구가 활발히 진행되고 있다. 이러한 문제점들을 해결 하고자 이류체 노즐 세정 장치와, 화학액 린스를 위한 초순수 Spray, 건조 공정에 해당하는 Air-knife, Halogen lamp로 구성된 소형화 된 고속 FPD(Flat Panel Display) 세정기에 대한 연구를 진행 하였다. 이류체 노즐은 초순수와 $N_2$ 가스를 내부에서 혼합하여 액적(Droplet)을 형성하여 고압으로 분사시키는 장치로서 화학액을 사용하지 않고 물리적인 방법으로 오염입자를 제거한다. Spray는 유기 오염입자 제거를 위한 오존수의 린스 공정을 위해 설치 하였다. 세정 후 표면에 남아있는 기판의 액막(water film)은 고압의 가스를 분사하는 Air-knife를 통해 제거하였으며, 고속 공정시 발생할 수 있는 Air-knife에서 제거하지 못한 잔류 액막을 Halogen lamp를 사용하여 효과적으로 제거함으로써, 물반점(water mark) 없는 건조 공정을 얻을 수 있었다. 실험에는 미세 입자의 정량적인 측정을 위하여 유리 기판 대신에 6인치 실리콘 웨이퍼(P-type (100))를 사용하였으며, > $\;1{\mu}m$ 실리카 입자를 스핀방식을 사용하여 정량적으로 균일하게 오염하였으며, 오염물의 개수 및 분포는 파티클 스캐너 (Surfscan 6200, KLA-Tancor, USA)를 사용하여 분포 및 개수를 정량적으로 측정 하였다. 이류체 노즐은 $N_2$ 가스의 압력과 초순수의 압력을 변화시켜 측정하여, 각각 0.20 MPa, 0.01 MPa에서 최적의 세정 결과를 얻을 수 있었으며, 건조 효율은 Air-Knife의 입사 각도와 건조면 간격, 할로겐 램프의 온도를 조절 하여 최적의 조건을 얻을 수 있었다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.3
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• pp.145-152
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• 1989

Volume phase diffraction grating is formed in 5${mu}m$ Agfa 8E75 photographic emulsion film using He-Ne laser. It is dependent on the chemical processing rather than materials themselves that high diffraction efficiency can obtained in silver halide emulsions. With potassium dichromate bleach and alcohol drying, overall efficiency of 71% (81% after allowing for reflection at the two surfaces) has been achieved at an exposure of 180${mu}J/cm^2.$ Dichromate cross-linkage and air void by rapid dehydration increase refractive index modulation depth. The grating is swollen, which is newly identified by Scanning Electronic Microscope(SEM) photography, and it causes on-Bragg at larger angle than the recording angle. It is pointed out that controlling the emulsion thickness has an important role as a potential source for high diffraction efficiency.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.19-25
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• 1980

Trials of investigating the effect of freezing and lyophilization, as the practical lactic starter preservation methods, on the viability and lactic acid producing activity of Lactobacillus bulgaricus NLS-4 have been carried out. After the treatments, both of viability and activity were decreased. However, when the initial cell cocentration was increared, the survival rate against freezing could be raised to 46% and the activity to 0.25% lactic acid whereas those against lyophilization were 22 ％ and 0.29% lactic acid, respectively. There were further increased maximally when the cell suspension was subjected to freezing and lyophilization after the addition of protective agents such as glycerol and the G. C. G. S. suspending medium.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.19-22
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• 2007

반도체 산업은 회로의 고밀도화, 고집적화에 따라 웨이퍼 표면의 입자, 금속, 금속 이온, 유기물 등 오염물의 크기가 미세해 지고 세정에 대한 요구 조건이 더욱 엄격해지고 있다. 현재 세정 공정은 반도체 제조공정 전체에서 약 30%를 차지하고 있으며, 습식 세정 방식이 주로 사용되고 있다.[1] 습식 세정방식은 탈이온수로 린스하고 건조하는 공정이 필연적으로 따르며, 기판 표면에 건조과정에서 물반점이 남는 문제가 가장 큰 이슈로 남아 있다. 본 연구는 웨이퍼의 습식 세정 공정에 사용되는 DHF Final Clean Process후 IPA Vapor를 이용한 건조 방법을 기술 하였다. Single wafer spin process를 이용하였으며, 웨이퍼 Process 공간을 밀폐 후 N2가스를 충진하여 대기중의 산소 오염원 유입을 차단하고 수세 및 건조 가스를 이용하여 건조시킴으로써 SiFx의 SiOx로의 치환을 방지 하여 건조 효율 향상을 목적으로 한다. Bare 웨이퍼에서 65nm 이상 오염 발생 증가량을 측정 하였으며, 공정 후 웨이퍼 오염 발생량을 35개 이하로 확보 하였다.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.313-320
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• 1993

A sublimation model of the freeze drying process, which accounted for the removal of free water, was presented and used to study the operation conditions of freeze driers for carrot juice. It was found that the shortest drying time was obtained when the condenser temperature and chamber pressure were kept at heir lowest values and the plate temperature was controlled independently so that the scorch and melting constraints were both held throughout the drying period. The effect of sample thickness on the drying time was significant. Optimal policies were investigated experimentally in laboratory freeze dryer.