• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1337-1344
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• 1999

Lactic acid bacteria fermented foods were prepared from egg white powder, casein and growth stimulating agent. pH change and growth of Lactbacillus acidophilus(KCTC 2182) during freeze drying were studied. The effects of freeze drying on sensory evaluation. hardness and volatile aroma compounds in freeze dried sample or reconstituted sample were also studied. Freezing and freeze drying did not affect pH of fermented samples. Number of viable cells in original fermented samples was markedly reduced during freezing or freeze drying. When number of viable cells in original fermented sampler was considered at 100%. survival ratio of viable cells after freezing was $72.0{\sim}82.4%$ and that after freeze dying $10.0{\sim}20.4%$. When sensory properties of original fermented samples were compared with those of freeze dried/reconstituted samples, sensory properties of original samples were generally better than those of freeze dried/reconstitute samples. However, the reconstitution property and the acceptability of freeze dried samples were good. Volatile aroma compounds in original fermented samples were reduced during freeze drying. The reduction degree of volatile aroma compounds varied with sample.

• Journal of the Korean Wood Science and Technology
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• v.14 no.3
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• pp.3-15
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• 1986

This study was carried out to investigate the drying rate and drying defects of Populus euramericana using the SDR (Saw-Dry-Rip) process. Flitches for SDR process were rough edged for compact kiln stacking, and then kiln-dried to 10 percent moisture content with dimensions in the same run, using the kiln-drying schedule ($T_8-F_4$) recommended by Rasmussen. The results obtained were as follows: 1. Drying rate of dimensions was slower than that of flitches. 2. Final moisture content and moisture distribution of dimensions were lower than those of flitches. 3. Average bowing, cupping, crooking, and twisting were reduced 20 percent, 25 percent, 54.9 percent, and 13.4 percent by SDR process respectively. 4. Bowing and cupping were more severe in dimensions from the area near the pith than in those from the area near the bark, and for crooking and twisting the reverse was true. 5. Surface checking of dimensions developed less than that of flitches and end checking of dimensions was similar to that of flitches. 6. Honeycomb, thickness shrinkage, and collapse of dimensions were similar to those of flitches. 7. The degree of casehardening of dimensions was higher than that of flitches.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.224-231
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• 2012

We investigated the effects of various washing methods on the quality of semi-dried Pacific saury Cololabis saira, known in Korea as Guamegi. We immersed samples for 5 min in seawater, tap water, chlorinated water (100 mg/kg), ammonia water (100 mg/kg), citric acid (0.1 M), butylated hydroxyanisole (BHA, 0.2 g/kg), or sesame oil (5 g/100 g), and then dried them in the sun for 3 days. The moisture and crude lipid contents after drying were 26.62-32.49 g/100 g and 26.40-33.01 g/100 g, respectively. The moisture content significantly decreased while the crude lipid content increased during drying. The different washing methods did not have a significant effect on the acidity, peroxide values, or levels of thiobarbituric acid or biogenic amine in Guamegi. The lightness of Guamegi during drying significantly decreased, but this decrease was not significantly different among washing methods. The degree of acceptance in a sensory evaluation was higher for Guamegi treated with sesame oil. Our results suggest that these washing methods should not be used to inhibit lipid oxidation, biogenic amine formation, or color changes in semi-dried Pacific saury, because effective components are extracted by the lipids during drying.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.392-398
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• 1988

Gelatinized rice flours were prepared by drum drying at different moisture contents of slurry made from dry milled and wet milled rice flours. Milled rice samples were prepared from the Chuchung and the Samgang varieties. Degree of gelatinization of drum-dried rice flours revealed over 92% at 60% moisture content of wet milled rice flours and 80% moisture content of dry milled ones. With regards to amylogram and rheological properties, drum-dried rice flours prepared from wet milled raw materials showed higher viscosity than from dry milled ones. Increasing water contents in the slurry increased water absorption index(WAI) and decreased water solubility index(WSI). Hunter's color values of drum-dried rice flour at high moisture contents showed higher L values and lower b values. For the preparation of gelatinized rice flours by drum drying process, the higher water content caused more gelatinized network structure of rice starch in scanning electron micrographs. With regards to farinogram properties of dough with drum-dried rice flours and wheat flours in mixing ratio of 1 to 9 by weight, drum-dried rice flours made from wet milled raw rice flours revealed higher MTI than from dry milled ones.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.22-40
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• 2015

Cellulose fibers is one of the most abundant in nature. It has many distinctive features: abundant in nature, biodegradable, non-toxic, eco-friendly, sustainable, easy to fabricate, hydrophilic, and cost-effective. Cellulose fibers, known as pulp, is produced from cellulose-containing materials by the pulping process. As the raw material, wood has been most commonly used while recycled pulp has been also used to some degree. Thus, pulp usually refers to wood pulp. Generally, the pulp and paper industry is regarded as the commodity market where the cost should be much more important than the quality. It also belongs to a mature market where the growth is slow, or even in decline. Accordingly, technological development has been rather stagnant for the industry. Recently, however, the pulp and paper industry has faced very serious challenges. First, due to digital technology, there has been a steady decline in the need for pulp and paper products. The digital industry has continuously replaced printed products such as books, newspapers, and magazines. Second, there has been a trend initiated by developed countries to limit the use of wood as the raw material for the sake of environmental protection. This forces the industry to find a more efficient use of wood pulp as well as finding alternative, non-wood sources. Third, as an individual becomes wealthier and more conscious of health-care, the quality of a product becomes more important than the cost. Thus, a paradigm shift is needed from the cost-conscientious to the quality conscientious. The objective of this article is to review the technologies aimed at engineering cellulose fibers for producing high-value added paper products.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.39-47
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• 2015

In this study, the properties of strength and drying shrinkage of alkali-activated slag cement (AASC) with magnesium oxide (MgO) contents between 0 and 16 wt% were investigated. The ground granulated furnace blast slag (GGBFS) was activated by potassium hydroxide (KOH) and dosage of activator was 2M and 4M. The MgO was replaced with 2% to 16% of GGBFS by weight. The water-binder ratio (w/b) was 0.5. In the result, the higher MgO content leads to a slightly higher degree of reaction and thus to a higher compressive strength at all ages. The compressive strength and ultra sonic velocity (UPV) increased with increases MgO contents. The drying shrinkage of AASC was decreased as the contents of MgO increases. The results from SEM confirmed that there were densified reaction product of higher MgO content specimens.

• Korean journal of food and cookery science
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• v.31 no.5
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• pp.596-604
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• 2015

This study investigated changes in the chemical properties and antioxidant activity of dried shredded radish (Raphanus sativus L.). Shredded radishes with a thickness of either 3.5 mm or 7.0 mm were dried using hot air at $45^{\circ}C$ or were sun dried. The degree of browning for the 3.5 mm sun dried radish, the 7.0 mm sun dried radish, the 3.5 mm hot air dried radish and the 7.0 mm hot air dried radish was 0.12, 0.14, 0.04 and 0.04, respectively. The DPPH radical scavenging activity (EDA%) of the hot air dried radish had a higher value than the sun dried radish. In contrast, the ABTS values of the sun dried radishes were higher than the hot air dried radishes. The total polyphenol content of the 7.0 mm and 3.5 mm hot air dried radishes reached high values of 15.99 and 11.62 mg/g, respectively. The total polyphenol contents of the 7.0 mm and 3.5 mm sun dried radishes were 9.63 and 6.77 mg/g, respectively. In sensory evaluation of the stir-fry dried shredded radishes, the 7.0 mm hot air dried sample scored the highest in terms of smell, color, gloss and overall preference. In conclusion, hot air drying ($45^{\circ}C$) and a thickness of 7.0 mm were found to be the optimal conditions for dried shredded radish and stir-fried dried shredded radish products.

• Journal of Powder Materials
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• v.26 no.1
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• pp.6-10
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• 2019

In this study, freeze drying of a porous Ni with unidirectionally aligned pore channels is accomplished by using a NiO powder and camphene. Camphene slurries with NiO content of 5 and 10 vol% are prepared by mixing them with a small amount of dispersant at $50^{\circ}C$. Freezing of a slurry is performed at $-25^{\circ}C$ while the growth direction of the camphene is unidirectionally controlled. Pores are generated subsequently by sublimation of the camphene during drying in air for 48 h. The green bodies are hydrogen-reduced at $400^{\circ}C$ and then sintered at $800^{\circ}C$ and $900^{\circ}C$ for 1 h. X-ray diffraction analysis reveals that the NiO powder is completely converted to the Ni phase without any reaction phases. The sintered samples show large pores that align parallel pores in the camphene growth direction as well as small pores in the internal walls of large pores. The size of large and small pores decreases with increasing powder content from 5 to 10 vol%. The influence of powder content on the pore structure is explained by the degree of powder rearrangement in slurry and the accumulation behavior of powders in the interdendritic spaces of solidified camphene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.635-640
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• 2006

This study was conducted to determine the effect of far infrared ray drying on the microbial and quality changes of vacuum packaged waxy corns, such as microbial growth, rehydration, color differences, weight loss and hardness during the storage at $4^{\circ}C$ and $25^{\circ}C$ for 7 months. After far infrared ray drying for 6 hours at $60^{\circ}C$, 2.32 log CFU/g of total microbial counts in raw waxy corns was enumerated, but no microorganism was detected in steamed or sugar-treated waxy corns. However, no microorganism was observed in all treatments except for control samples until 3 month storage at $4^{\circ}C$, whereas steamed and sugar-treated waxy corns showed 2 and 2.7 log reduction compared to that of control after 3 month storage. Yeasts and molds were more resistant than bacteria against far infrared ray drying at the same conditions. Similar results were observed in $25^{\circ}C$ storage. The degree of gelatinization in raw waxy corns far infrared ray drying changed from 98% to 96.2% after 7 month storage at $4^{\circ}C$, whereas steamed waxy corns with far infrared ray drying changed from 81.14% to 58.73%. Water contents in sugar-treated waxy corns with far infrared ray drying gradually reduced compared to steamed waxy corns as drying time increased. The L values in raw waxy corns far infrared ray drying increased as drying time increased, but L values in steamed or sugar-treated waxy corns significantly reduced after 12 hour far infrared ray drying. Hardness in raw waxy corns was higher than in steamed or sugar-treated waxy corns before storage, but similar hardness was observed between raw- and sugar-treated waxy corns after 9 hour drying. This results showed that the microbial reduction, the enhancement of shelf life and quality establishment of steamed or sugar-treated waxy corns could be maximized by using far infrared ray drying.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.429-432
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• 2006

The shrinkage mechanism of high strength concrete is different from that of normal concrete. The shrinkage of normal concrete is subjected to evaporate moisture in concrete, but most shrinkage in high strength concrete is caused by chemical reaction. To analyze shrinkage of concrete exactly, it is necessary to divide drying shrinkage with autogenous shrinkage in terms of degree of hydration, especially in concrete with low W/C ratio. The proposed method can provide a rational basis for prediction of shrinkage in high strength concrete structure.