• Journal of Biosystems Engineering
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• v.35 no.6
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• pp.393-400
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• 2010

Uniform and rapid pre-drying of mandarin is important to improve the storage quality. The aim of this study was to suggest the basic design of forced ventilated pre-drying facility for mandarin by thermal flow analysis using computational fluid dynamics software (FLUENT 6.2). Developed CFD simulation model was verified by comparison with experimental data. Airflows and temperature distributions in the five conceptional designs including existing ordinary temperature storage rooms were analyzed and appropriate basic design was determined. Analysis of the effect of arrangement of windows and exhaust fans on thermal flow in facility was carried out for more detailed design. The results of this investigation showed that the predicted airflow velocity by CFD simulation showed a good agreement with the measured value and optimum design condition for simulated forced ventilated pre-drying facility of mandarin has two exhaust fans and two windows on both sidewalls and cover on loaded mandarin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.171-176
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• 1975

Gae-bul, Urechis unicinctus, fresh or sun-dried has been esteemed as one of the most tasty sea foods in Korea. In this paper, the degradation of nucleotides and their related compounds in Gae-bul during sun drying was studied. The nucleotides and their related compounds were extracted with cold perchloric acid and their amounts were determined by anion exchange column chromatography. In fresh Gae-bul, the results showed that AMP was dominant and the content of ATP, ADP, AMP and inosine were 0.6, 3.5, 6.8 and $0.7{\mu}\;mole/g$ on dry base respectively while IMP was not detected. AMP tended to degrade slowly and ATP and ADP decreased rapidly while inosine ana hypoxanthine increased remarkably sun drying. In dried sample, the content of AMP was the highest, $5.6{\mu}\;mole/g$ on dry base, whereas ATP, ADP, inosine and hypoxanthine were lower.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1182-1187
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• 2007

Changes in composition of fatty acids and free amino acids in three differently dried Alaska pollack (sun dried, naturally cyclic freeze-thaw dried, and 1-year-aged cyclic freeze-thaw dried Alaska pollack (Hwangtae)) were investigated to correlate them with browning reactions in drying and aging Alaska pollack. Major fatty acids of the sun dried Alaska pollack were palmitic acid, oleic acid, and eicosapentaenoic acid (EPA), and those in the Hwangtae were palmitic acid, oleic acid, and gondoic acid. Hwangtae showed the lowest amount of polyunsaturated fatty acids among the three types of dried Alaska pollack. Free amino acids content of sun dried Alaska pollack was higher than that of the cyclic freeze-thaw dried Alaska pollack and Hwangtae. Lesser amount of histidine in Hwangtae (0.02%) than that in the cyclic freeze-thaw dried Alaska pollack (0.087%) may indicate the degradation of histidine due to the browning reaction in aging the cyclic freeze-thaw dried Alaska pollack. Significant changes in compositions of fatty acids and free amino acids among the dried products revealed the browning reaction resulted from carbonyl compounds produced by decomposition of lipid hydroperoxides and free amino acids. Aging the cyclic freeze-thaw dried Alaska pollack for a year contributed to the development of browning.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.354-361
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• 2011

In order to product dry goods of Gastrodiae Rhizoma with high quality, tubers were treated with various dry methods such as cutting, drying methods and steaming. In cutting than no cutting, they were shown shorter drying hours and lower drying yield. Drying hours in freeze drying was shorter than those of hot air and far-infrared ray. Total polyphenol content was higher in cutting than no cutting. According to steaming, it was increased in freeze drying but decreased rapidly in the other dry methods. Among all treatments, hot air dry treatment with cutting and no steaming had the highest total polyphenol content. Gastrodin and 4-hydroxybenzyl alcohol contents generally were similar or higher in cutting than no cutting. By steaming, gastrodin content in freeze drying was decreased but 4-hydroxybenzyl alcohol content was increased. But hot-air and infrared ray dry, they were shown opposite results. Gastrodin and 4-hydroxybenzyl alcohol contents showed opposite reaction to each other and were shown various response by dry methods.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.85-91
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• 2010

In this study, the drying shrinkage strains were compared of 24~60 MPa concrete specimens subjected to various curing conditions and measurement methods were compared. And, the applicability of the test and prediction methods were investigated. According to the results, drying shrinkage was significantly reduced in 28 day curing condition. In the sealed curing case, drying shrinkage strain from demolding time was identical to the one of the standard curing case for low strength concrete, however, drying shrinkage strain was greatly increased than the standard case for high strength case because of the effect of autogenous shrinkage. The efficient measurement was possible using the embedded gage for concrete drying shrinkage, but, the measured value by contact gage was lower than the one by the embedded gage. The test results agreed with EC2 model better than the other.

• Journal of Radiation Industry
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• v.6 no.1
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• pp.89-94
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• 2012

Three-dimensional network hydrogels were prepared by ${\gamma}$-irradiation of aqueous solutions of poly(vinyl alcohol) (PVA) and glycerol (Gly). Oven-drying was used to measure the gel fraction (G), hydration (H) or swelling behavior (S) of the prepared hydrogels. This study made a hypothesis that hydrogen bonds due to addition of glycerol and change of dry states such as freeze-drying (FD), room-drying (RD) and oven-drying (OD) acts on the G, H, and S. Interesting results on the hydrogen bonding effect in the prepared hydrogels are monitored at different drying conditions. The FD samples have a higher G values with increase in glycerol content as compared with the OD and RD samples. The formation of strong hydrogen bonding network among Gly molecules and hydrogel matrix was considered as the main driving force, resulting in the changes in the G, H, and S of the hydrogels under different drying conditions.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.805-813
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• 1994

Zucchini slices, sweet potato stems, taro stems, and platycodon treated with various methods such as dipping in citric acid solution, sulfite solution, or sulfur fumigation were dried by the natural sun drying method or the forced air drying method at 50, 70, 90, or $105^{\circ}C$. Mold growth of the dried vegetables and sensory quality of the dried and rehydrated vegetables were investigated. Limiting moisture contents to prevent mold growth over 3 month storage under room temperature were 15, 20, 25, and 15% for zucchini slices, sweet potato stems, taro stems, and platycodon, respectively. The chlorophyll containing vegetables dehydrated by the forced hot air showed better sensory quality than those by the natural sun. Among the pretreatments, dipping in the sulfite solution provided the best sensory quality to the dried vegetables. The sensory quality of dried platycodon was improved to a small extent by sulfur fumigation and sulfite solution treatment. The sensory quality of the dried platycodon was not found to be affected by the drying methods. All the tested vegetables dried at $105^{\circ}C$ had the worst sensory quality. Except drying temperature of $105^{\circ}C$, the lower the drying temperature, the better the sensory quality and the rehydration rates were obtained for the tested vegetables except platycodon. The sensory quality of the platycodon was little affected by the drying temperature tested in the range of $50{\sim}90^{\circ}C$.

• Fashion & Textile Research Journal
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• v.1 no.3
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• pp.259-263
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• 1999

This study was carried out to investigate the changes of thermal properties such as warmth retaining and contact warm/cool feeling of commercial dress shirts by repeated washing and drying by sun and dryer. Three kinds of fabrics such as cotton 100%, cotton/polyester 80/20% and polyester 100% were repeatedly washed and dried, and then used as specimen. Thermo Labo II type was employed to measure the thermal properties. At the same time, structural properties such as thickness, weight, bulk density, porosity, moisture vapor permeability and air permeability were analysed.

• Journal of computational fluids engineering
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• v.20 no.3
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• pp.70-78
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• 2015

Turbulent flow and heat transfer characteristics of textile machine are numerically investigated. To examine the influence of flow structures on the drying performance of fabrics, the nozzle shape of high temperature chamber is changed. For several nozzles, flow and heat transfer characteristics are discussed. The results show that the drying performance is improved by controlling the angle and arrangement of nozzles corresponding to different drying conditions. This feature is strongly related to the enhancement of turbulent fluctuations and secondary flows.

• Plant Resources
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• v.5 no.2
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• pp.124-140
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• 2002

The effects of drying agents and ethyl alcohol treatment on the flower color of Gentiana uchiyamai. The flower color was not much changed in flower sheet, in the case of absorbtion papers only. The color was least changed in Korean and China hwasunjis, in the case of absorbtion papers and silica gel treatment. The color was less changed in flower sheets, window papers, and China hwasunjis, and was most changed in newspapers, in the case of absorbtion papers and Na$_2$SO$_4$ treatment. The color was least changed in China hwasunjis, and most changed in dampened papers, in the case of absorbtion papers and CaO treatment. The color tended to change far from the original one, as treatment time got longer, in the case of 0.01M and 0.lM of tartaric acid. The longer the treatment time and the bigger the concentration of ethyl alcohol, the bigger flower color.