• Journal of Ocean Engineering and Technology
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• v.11 no.2
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• pp.48-56
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• 1997

This work has been investigated in order to study the influence of the moisture absorption on the mechanical pf the glass fiber/epoxy resein composites and the carbon fiber/epoxy resein composites. The types of glass fiber used in the glass fiber/epoxy resein composites were randomly oriented fiber and plain fabric fiber. And carbon fiber.epoxy resein composites was laminated with fabric prepreg which was formed with carbon fiber and epoxy resein. Both composites were immersed up to 100 days in distilled water at $80^{\circ}C$, and then dried up to 3 days in an oven at 80$80^{\circ}C$. Both composites were measured for the weight gain of water(wt.%) and tensile strength through immersion and dry time. Consequently, it was found that the tensile strength of thw glass fiber/epoxy resein composites and the carbon fiber/epoxy resein composites were reduced proportionally to the moisture absortion rate. Also, the tensile strength of glass fiber composites was decreased more than that of the carbon fiber composites. Additionally, it was found that the tensile strength of all composites which decreased by moisture absorption were partly recovered by drying in an oven at 80$80^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.155-159
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• 1983

Alpha-barley were prepared by means of soaking, heating, and drying treatment. The degree of gelatinization ${\alpha}-barley$ were determined. The yield of ${\alpha}-barley$ prepared by microwave heating, steaming, and autoclaving were in the range of 95-98%, whereas by boiling, only 74-89% of ${\alpha}-barley$ were obtained. The degree of gelatinization of ${\alpha}-barley$ prepared by 5 min microwave heating and 10 min and 20 min steaming were around 90%. Alpha-barley prepared by boiling, autoclaving and 30 min steaming showed above 95% of degree of gelatinization.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.55-59
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• 2001

Pressure-puffing system or extruder has been used to puff rice kernel or rice flour. Most of the study on rice puffing were the effect of process conditions such as moisture content and heating temperature on physical and chemical characteristics of popped rice. The study on mechanism and development of instant puffed rice like popcorn has been limited. Extruded waxy rice pellets were puffed in a microwave oven after drying and conditioning. Extruded pellets were formed with extrusion conditions of $20{\sim}27%$ moisture content, 2.76 MPa $CO_2$ gas injection pressure and 200 rpm screw speed. Under these conditions, puffed waxy rice pellets in microwave oven had low density and soft texture. Density and texture of puffed waxy rice pellet could be optimized by control of moisture content, $CO_2$ gas injection pressure and screw speed that affect significantly when puffing extruded waxy rice pellet.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.51-56
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• 2016

The most widely used glue in a corrugator is starch, which is a natural polymer. This material needs thermal energy to achieve a binding force, so a heating section is installed in a corrugator. However, this heating section can cause quality problems in linerboards and corrugating medium and increase the production cost because of the high cost of fossil resources. Therefore, a new adhesive that provides the binding force at lower temperatures than the conventional one must be developed. In this study, SB-latex was selected as a co-adhesive and added to the starch solution. The addition of the SB-latex was determined based on the viscosity of the new adhesive. The adhesive strength and the drying energy reduction of a corrugated board were measured to evaluate the functionalities of the new adhesive. The addition of SB-latex was determined to be under 20% of the oven-dried starch based on the viscosity of the new adhesive. The adhesive strength was improved and the drying energy was reduced by applying the new adhesive.

• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.641-646
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• 2012

Objectives : The purpose of this study is to analyze the sterilizing effects of toothbrushes by administering bacteria into toothbrushes and reproducing the antibacterial effects using a microwave oven. Methods : The heads of four-row mid-strength toothbrushes were cut, put in a bacterial solution ($3{\times}10^9cells/ml$) for vortexing, and sterilized with microwaves for 0, 30, and 60 seconds. They were then moved into four tubes containing DW 10 ml and suspended in a vortex mixer for two minutes to separate bacteria from them. DW 9ml was added by 1ml of bacteria for dilution of $10{\sim}10^6$ times. It was then administered to the BHI agar plate by 0.1ml and cultured at $37^{\circ}C$ for 24 hours. Total number of bacteria adhered to a toothbrush was obtained by multiplying the number of colonies by the dilution factor. The experiment was done in the first, second, and third step, being repeated in a normal temperature drier ($23^{\circ}C$) after 5, 9 and 24 hours. Results : The results of the experiment revealed that the sterilizing effects were 95% or over. When toothbrushes were sterilized for 60 seconds, the number of colonies is about 11 after drying for 5 hours, 7 after drying for 9 hours and 2 after drying for 24 hours. The sterilizing effects reached 98% when the bacteria-administered toothbrush was sterilized for 1 minute after drying for 24 hours. Conclusions : The results demonstrated that toothbrush sterilizing by using microwave is a suitable way to prevent cross-contamination of toothbrushes by oral bacterial infection and thus easy to use at home. However, this study suggests that toothbrush sterilizing by using microwave should be limited within two times a week because the physical properties of toothbrush might be changed.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.7-16
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• 2017

BACKGROUND: Increased value added by rapeseed (Brassica napus) by-product and the development of a usable rapeseed functional tea. METHODS AND RESULTS: To develop a usable rapeseed functional tea, the total flavonoid content in the varieties Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111 was investigated. Effect of three treatments, i.e., drying, leaching, and roasting, on flavonoid contents or flower was tested using multiple processing methods per treatment. Total flavonoid content decreased under the various drying methods, confirming that flavonoid content is heat-dependent. This finding was more pronounced for freezing and oven-drying (15.3 and 13.8 mg/g DW, respectively), with a 10% difference in the total flavonoid content between the two methods. Under leaching conditions, the flavonoid content decreased with increasing treatment time. Notably, roasting methods did not result in loss of flavonoid content. The total flavonoid content in the rapeseed varieties decreased in the following order: Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111. CONCLUSION: The flavonoid content in rapeseed flower was higher in Youngsan than in the other varieties, under processing conditions such as freeze-drying, leaching at $90^{\circ}C$ for 5 min, and roasting.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.25-31
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• 1999

The differences in seed germination rates of Korean Native Plants were observed depending on the harvest years, the seed companies, the storage periods, the drying methods and the plant morphological types. The seed germination rates were changed significantly by the harvest years and the seed companies in all 4 species tested. The seed germination rates were decreased after 1 year storage at $4^{\circ}C$ in all 8 species tested and three of them did not germinate at all. A rapid drying method at $35^{\circ}C$ with a convection oven was not suitable for Chrysanthemum spp., but there were no significant changes of germination rates in Aster spp. The germination rates were decreased more at seeding in soil than at lab. test with Dicotyledon but no significant changes with Monocotyledon. Especially, the germination rates of fine seed on 5mm soil covering treatment were significantly decreased.

• Clean Technology
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• v.24 no.2
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• pp.119-126
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• 2018

This study introduced a treatment process that was developed to treat Indonesian low-rank coal with high-ash content, which has the same characteristics as residual coal from the biosolubilization process. The treatment process includes separation of ash, solid-liquid separation, pelletizing, and drying. To reduce the ash content, flotation was performed using 4-methyl-2-pentanol (MIBC) as frother, and kerosene, waste oil, and cashew nut shell liquid (CNSL) as collectors. The increasing amount of collector had an effect on combustible coal recovery and ash reduction. After flotation, a filter press, extruder, and an oven drier were used to make a dried coal pellet. Then another coal pellet was made using asphalt as a binder. The compressive strength and friability of the coal pellets were tested and compared.

• 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 $50{\sim}90^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.746-756
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• 2015

The goal of this study was to review the wood shrinkage published in Journal of The Korean Wood Science and Technology from 1976 to 2015. Previous studies reported that shrinkage from Larix kaempferi in the tangential, radial, longitudinal directions ranged from 4.21%-9.79%, 2.09%-4.67%, 0.17%-0.33%, respectively. When different drying methods including closed cylinder drying, oven drying, and room temperature drying were used, volumetric shrinkage of Dipterocarpus grandiflorus was different, ranging from 31.6% to 21.0%. With an increment of the drying temperature of $115^{\circ}C$, $120^{\circ}C$, $125^{\circ}C$, the shrinkage of Larix kaempferi did not show a consistent trend. When sample size of Pinus densiflora was increased from $20{\times}20{\times}20mm$ to $100{\times}100{\times}100mm$, the tangential, radial and volumetric shrinkage decreased 2.61%, 1.32%, 0.80%, respectively. When a caliper having a sensitivity of 0.01 mm was used to measure $20mm^3$ specimen from Cryptomeria japonica, the measurement error occurred 1.97% in the radial direction and 35.7% in the longitudinal direction. From the previous studies, wood shrinkage could be influenced by sample size, drying method and measurement technique.