• Food Science and Preservation
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• v.4 no.2
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• pp.147-153
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• 1997

Oriental melon has been increased in production amount, but its processed food was not made in spite of the fact that shelf-life of the fresh fruit is short. This study was carried out to develop a dried product with no use sulfur treatment. Fresh melons were peeled, cut into 6 pieces, and soaked to the following pretreatments soaking in sugar syrup(SS), sodium chloride(SC), ascorbic acid(AA) and sodium polyphosphate(SP). After preatreatments the melon pieces were dried by hot air drying at 5$0^{\circ}C$ for 9 and 12 hours, and the dried melons were air blown at $25^{\circ}C$ for 1 day. The dried samples were evaluated for moisture content, texture, rotor, and sensory quality. The moisture content of dried melons soaked in SS and SC were lower than those that were soaked in AA and SP after hot air drying. The melons dried for 12 hours were high in hardness, gumminess, chewness and adhesiveness and excellent in sensory evaluation compared to 9 hours. The "L" value of SS was higher and the "a" value was lower in Hunter color. And SS treatment inhibited browning of the dried melon and improved sensory characteristics in color, flavor, texture and taste. Sucrose concentration had no significant effect on color, hardness and sensory score in banal product. The combination of SS with SP represented a highly effective antibrowning treatment for the dried melon and the product was kept in good color for 3 months at room temperature.at room temperature.

• Journal of Environmental Science International
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• v.27 no.4
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• pp.251-259
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• 2018

This study was conducted to determine the effects of combination of air temperature and soil water content on the growth, physiological disorder rate, and yield of hot peppers. The study was carried out in a typical plastic house (open on one side and with ventilation fans on the other side), which was maintained with gradient air temperature (maximum difference in air temperature: $6^{\circ}C$). The deficit irrigation (DI) treatment commenced 65 days after transplanting. The height of plant and fresh and dry weights of the stem increased at high air temperature (ambient + $6^{\circ}C$, extreme high temperature; EHT). Furthermore, the leaf area decreased significantly with the DI treatment. There were no significant differences in the stem diameter, number of branches, and fresh and dry weights of the leaves among all the treatments. The net photosynthesis rate of the full irrigation (FI) treatment was higher than that of the DI treatment. The photosynthesis rate at ambient air temperature was $19.7{\mu}mol\;CO_2m^{-2}{\cdot}s^{-1}$, the highest among all the treatments; however, the photosynthesis rate of the EHT treatment decreased by 60% ($12.3{\mu}mol\;CO_2m^{-2}{\cdot}s^{-1}$). Additionally, the formation of guard cells in the leaf was abnormal with the EHT treatment, and there was a decrease in translocation efficiency. The effects of air temperature treatment were more pronounced on the physiological disorder rate and yield. The physiological disorder rate of the EHT treatment was the highest under the DI treatment condition. The yield of the AFI (ambient air temperature with full irrigation) treatment was 3,771 kg/10a, the highest among all the treatments; however, the yield of the EHT treatment with DI and FI was 1,282 and 1,327 kg/10a, respectively. These results indicate that growth and physiological disorder rate improved with the EHT treatment; however, there was a decrease in yield. Furthermore, the formation of guard cells was abnormal and malfunctional.

• Textile Coloration and Finishing
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• v.10 no.3
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• pp.10-19
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• 1998

This paper investigates the change of mechanical properties and thermal shrinkage in commercial multi-filament PET(polyethylene terephthalate) , namely, regular yarn, POY, DTY and composite yarn. To determine changing the effects of processing steps, these were examined at three steps process simulation conditions. The first step is sizing simulation$(S-1\;step\;:\;130^\circ{C}\times2\;min$., hot air treatment under 0.1 gf/d load), the second step is scouring simulation$(S-2\;step\;:\;100^\circ{C}\times20\;min$., boiling water treatment under free tension)and final step is setting simulation$(S-3\;step\;:\;180^\circ{C}\times2\;min$., hot air treatment under free tension). Regular yarn in multi-step treatment showed higher shrinkage at S-3 step and DTY showed higher in at S-1 step. While POY was relaxed at S-1 step, composite yarn showed different shrinkage properties depending on composite yarn type. Mechanical properties showed good relationship with shrinkage : high shrinkage makes initial modulus decrease and bleating strain increase. It also makes decreasing yield strain and yield stress decrease.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.10
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• pp.974-981
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• 2001

In this study, the minimum heat flux conditions are experimentally investigated for the spray cooling of hot plate. The hot plates are cooled down from the initial temperature of about$ 900^{\circ}C$, and the local heat flux and surface temperatures are calculated from the measured temperature-time history. The results show that the minimum heat flux point temperatures increase linearly resulting from the propagation of wetting front with the increase of the distance from the stagnation point of spray flow. However, in the wall region, the minimum heat flux point temperature becomes independent of the distance. Also, the velocity of wetting front increases with the increase of the droplet flow rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.33-37
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• 1970

The effect of the dehydration method and EDTA or BHA treatment upon the pigment degradation and water re-absorption of the dehydrated meat of the surf clam Mactra Sulcataria REEVE was studied. Sun drying Produced a realer decrease in pigment content as compared to that produced by hot-air dehydration. The hot-air dehydrated product which was treated with BHA showed little pigment loss in comparison with the pigment of the fresh surf clam meat. The BHA treatment upon the dehydrated surf clam products had an outstanding effect on the pigment retention and the EDTA treated one had a weak effect on it. The hot-air dehydrated products more rapidly re-absorbed water than the sun dried one. It could be seen that there was tittle difference among the rate of rehydration of the BHA or EDTA treated product and untreated one.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.2
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• pp.46-53
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• 2000

Hot forging of aluminum alloy has the bad machinability due to continuous chip formation caused from the ductility The bad machinability requires a labor and a high cost to produce final products after hot forging. In industrial field, T4 heat treatment is performed to improve the machinability, and the annealing and the cold sizing are followed. In this study, a series of heat treatments are introduced during hot forging operation without T4 heat treatment after forming so that it improves the machinability with reduction of the number of operations and machining cost. Instead of T4 heat treatment, water cooling and air cooling are tried and compared to find out an optimum cooling condition

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.417-420
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• 1993

Changes in color intensity of Hololeion maximowiczii(HM) roots which were treated with freeze drying (FD), $50^{\circ}C$ hot air drying (HAD) and $50^{\circ}C$ hot air drying after steam blanching (HADB) were investigated in this study. Color of HADB was yellow-green while other treatments showed bright brown color. In brown color intensity, optical density at 420 nm of FD treatment was highest but HADB treatment showed the highest value in ultra violet spectrum. Water soluble pigment of HM in state of aquous solution was more unstable for heat treatment than that in state of powder. Activation energy for decomposition of the pigment was 20.9 kcal/mole between $90{\sim}100^{\circ}C$ but 50.6 kcal/mole between $80{\sim}90^{\circ}C$.

• Food Science and Preservation
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• v.15 no.4
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• pp.524-531
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• 2008

To investigate tea prepared from Ixeris dentata root, color, and levels of free sugars, organic acids, cynaroside, total polyphenolics, and free amino acids were investigated using various thermal processing methods. These included natural drying(ND), hot-air drying(HAD, $75^{\circ}C$), hot-air drying after steam(HADS, steaming at $95^{\circ}C$ for 30 min) and roasting after hot-air drying(RHAD, roasting at $140^{\circ}C$ for $2{\sim}3$ min). Total free sugars, organic acids, cynaroside, and free amino acids contents were highest after ND treatment. Total polyphenolics was highest after RHAD processing. The level of cynaroside, a principal component of Ixeris dentata root, was significantly decreased by HADS. The major free sugars were fructose, glucose and sucrose. Succinic acid was prominent among organic acids, and was present at 2.25%(v/v) after ND treatment. The lightness(L), redness(a), and yellowness(b) of all dried Ixeris dentata root powders were best after RHAD treatment, but analysis of the leaching liquids after hot water treatment yielded variable results. Lightness and redness were the highest after RHAD and yellowness was the highest after ND treatment. Overall, the RHAD drying method was found to be superior to other methods, in sensory evaluation tests.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.731-736
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• 2013

To improve their shelf-life, domestic peaches were treated with hot air($46^{\circ}C$) for 0~9 hour, and the spoilage rate, changes of physico-chemical and sensory properties were investigated. The control showed spoilage at day 4, and then 50% of control showed spoilage on day 6. However, 12.5% of samples treated with hot air($46^{\circ}C$) for 6 hr showed spoilage on day 4. After 6 days, the spoilage rates of peaches treated with hot air treated for 3~9 hr were 16.7, 25.0, and 25.0%, respectively. Weight change of control was higher than that of hot air-treated samples for 6 days storage. There were no differences in pH of samples among the treatments, but pH increased with storage time. Hardness of hot air-treated samples was higher than that of control in the initial stage of storage. And then hardness of control sample was decreased faster than that of the hot air-treated samples for 6 days of storage. No significant changes in lightness and redness of the samples were observed after hot air treatment. Changes in yellowness of control occurred faster than that of hot air-treated samples during storage. The sensory parameters including taste, flavor, color, texture and overall acceptance at initial period were not different among treatments. The scores for taste, flavor, texture and overall acceptance of control decreased faster than those of hot airtreated samples during storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.848-852
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• 2011

The aim of our study was to develop drying process of apple slice. Quality characteristics of apple slices dried by hot-air and freeze drying after osmotic dehydration was investigated in different sucrose solution (20, 40, $60^{\circ}Brix$) and steeping time (2, 4, 8 hours). The weight of apple slice before and after osmotic dehydration was measured for characteristic of mass transfer. Consequently, osmotic dehydration increases weight reduction, water loss and solid gain of apple slice as the concentration of the sucrose solution and steeping time increased. Moisture contents of apples slices dried hot-air and freeze were about 3 to 7%. Hunter color L, a, b value was lower than non-treatment to osmotic dehydration of apple slice. In hot-air drying, L value decreased as the concentration of the sucrose solution and steeping time increased. The hardness increased as the concentration of the sucrose solution and steeping time increased. Contents of monosaccharide (glucose, fructose) decrease by osmotic dehydration but sucrose increased. In comparison with hot-air drying, freeze drying was high in contents of free sugar.