• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.876-882
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• 2015

The aim of this study was to investigate changes in the biochemical characteristics of the Pacific oyster Crassostrea gigas in response to boiling water bath ($85^{\circ}C$, $100^{\circ}C$) and autoclaving ($100^{\circ}C$) heat treatments for 5, 10, 15, and 20 min. The weight loss (7.6-9.5%) of oysters exposed to a $100^{\circ}C$ boiling water bath for 15 min was lower compared to those receiving no treatment. Oysters exposed to the $100^{\circ}C$ boiling water bath for 20 min lost 27.8% of their total weight. The $100^{\circ}C$ autoclaving treatment resulted in weight loss of 13.0-26.1%, with the highest weight loss occurring after 10 min of treatment (26.1%). Heat-treated oysters had significantly higher levels of crude lipid and crude protein relative to untreated oysters (P<0.05). In the heat-treated oysters, total amino acids (including proline and glutamic acid) were increased, but they were decreased by the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments. The fatty acid composition of oysters was not significantly affected by the water bath heat treatment, but oysters treated with $100^{\circ}C$ autoclaving for 20 min had decreased polyunsaturated fatty acids. Oysters exposed to the water bath heat treatment had significantly increased vitamin A content, but $100^{\circ}C$ autoclaving for 20 min was associated with reduced vitamin A content, as compared to all of the other heat treatments. Therefore, oysters were affected by heat treatment, undergoing metamorphosis and weight loss, but nutrient quality did not change significantly compared to controls, except with the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.57-64
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• 2002

Finite element program(ANSYS) estimated thermal deformation quantity in high frequency heat treatment process of a machine tool fred drive system slideway and apply deformation quantity in roughing process. Having processed the heat treatment minimizing methods of the quantity of deformation heat treatment process. Having done heat treatment with high frequency after taper processing with considering the existed heat treatment generating the quantity of deformation, existed quantity of deformation can be reduced down to 80%, consequently productivity and material saving can be achieved. When high frequency heat treatment finite element method estimated deformation quantity at difference temperature and time, it is progress at cost don and saved time.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.523-528
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• 2006

The digestibility of heat- or high-pres sure-treated beef extracts was evaluated with an in vitro simulated gastric digestion model and each sample also underwent immune assay to detect its antigenicity with the sera of beef allergic patients. Heat treatment of the beef extracts considerably decreased their digestibility, whereas high-pressure treatment at 200 MPa improved their digestibility compared with the control, but the difference was not significant. The digestibility of the high pressure-treated beef extract was generally higher than that of the heat-treated samples. Depending on the degree of digestion, the degree of antigenicity of the main beef allergens decreased. On the basis of these results, we hypothesized that the allergenicity of beef could be eliminated if the allergenic proteins are sufficiently digested in the digestive organ, leading to the suggestion that the digestibility of allergenic proteins must be improved in food processing. In conclusion, high-pressure processing is a more acceptable food processing technique for beef considering its digestibility.

• Transactions of Materials Processing
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• v.15 no.8 s.89
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• pp.539-543
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• 2006

Experimental studies are carried out in order to investigate the effects of heat treatment on the surface machined by W-EDM. In this work, two ways of heat treatment after W-EDM are considered. As a comparison, the machined surface by a traditional method such as milling/grinding is also considered. Thereby, specimens are prepared by four different machining methods. Those are (1) milling and then grinding, (2) wire-cut electric discharge machining (W-EDM), and (3) low temperature heat treatment or (4) high temperature heat treatment after W-EDM. The resulting surface roughness are measured and the changes of surface microstructures are investigated using the scanning electron microscope (SEM) with energy dispersive X-ray spectrometer (EDS). In general, heat treatment after W-EDM result in smoother surface and better chemical composition at the machined surface. Especially, high temperature tempering could remove defects in the thermally affected zone, which cause an overall deterioration of the surface machined by W-EDM.

• Journal of Korea Foundry Society
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• v.41 no.4
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• pp.331-341
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• 2021

The effects of austempering temperature, austenitizing temperature and time, added copper content and prior heat-treatment on the processing window of 3.6wt%C-2.5wt%Si ductile cast iron during austempering. The maximum processing window was obtained at 350℃ of austempering temperature. The processing window was increased with increased austenitizing temperature from 850 to 900℃; however, it decreased at 950℃. The processing window was increased with increased austenitizing time from 0.5 to 2 hours and rather decreased for 4 hours. The optimum condition of austenitizing was obained at 900℃ for 2 hours. The processing window was increased with copper content added in the range of 0.0~0.8wt%. The processing window was increased by prior normalizing heat-treatment and decreased by prior annealing in comparison with that for the as-cast state,

• Food Science of Animal Resources
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• v.37 no.1
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• pp.44-51
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• 2017

Heat treatment of milk aims to inhibit the growth of microbes, extend the shelf-life of products and improve the quality of the products. Heat treatment also leads to denaturation of whey protein and the formation of whey protein-casein polymer, which has negative effects on milk product. Hence the milk heat treatment conditions should be controlled in milk processing. In this study, the denaturation degree of whey protein and the combination degree of whey protein and casein when undergoing heat treatment were also determined by using the Native-PAGE and SDS-PAGE analysis. The results showed that the denaturation degree of whey protein and the combination degree of whey protein with casein extended with the increase of the heat-treated temperature and time. The effects of the heat-treated temperature and heat-treated time on the denaturation degree of whey protein and on the combination degree of whey protein and casein were well described using the quadratic regression equation. The analysis strategy used in this study reveals an intuitive and effective measure of the denaturation degree of whey protein, and the changes of milk protein under different heat treatment conditions efficiently and accurately in the dairy industry. It can be of great significance for dairy product proteins following processing treatments applied for dairy product manufacturing.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.1
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• pp.42-48
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• 2001

• Transactions of Materials Processing
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• v.12 no.3
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• pp.221-227
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• 2003

Heat treatment is widely used in various manufacturing Processes to enhance the quality of a Product such as strength, surface hardness, and service life. In the heat treatment, there is dimensional change or distortion of the product, which critically influences the dimensional accuracy of precision parts. In this study, the distortion of a straight bevel gear induced by heat treatment is investigated in two cases. In the first case, the distortion induced by heat treatment we compared between a forged bevel gear and a machined bevel gear. In the second case, the distortion of an annealed gen is compared with that of a quenched gear. And finite element analysis has been Performed to predict the distortion of a heat-treated and machined bevel gear. The predicted values are compared with the experimental values.

• Journal of the Korean Wood Science and Technology
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• v.51 no.6
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• pp.447-447
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• 2023

This study aimed to convert underutilized moso bamboo into high-value added products such as fences, interior materials, lighting fixtures, and accessories. Green moso bamboo poles with a diameter of approximately 10 cm and a length of approximately 3.7 m were heat treated at 140℃ using a large-scale kiln. The processing time was meticulously adjusted through various stages, including pretreatment (6-8 hours at 60℃), cooking (8-10 hours at 100℃), steaming (26-30 hours at 120℃), heating (4-6 hours at 140℃), and finally, cooling (below 80℃). A meticulously designed heat treatment process has enabled efficient mass production of moso bamboo poles with improved qualities, including minimal splitting, moisture levels below 3%, and a specific gravity of 1.05. The focus of this study was to present the physical and drying properties, such as color, dimensional change, specific gravity, moisture content, and splitting, observed during the heat treatment process.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.2
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• pp.96-102
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• 2006

Development of Rotation-Cylinder Method(RCM) is given for Mg-Al-Zn-X(X=Sr) alloys, identifying some of the key factors that need to be controlled and indicating subsequent casting processes. Effects of Sr addition on the microstructure and mechanical properties of as-cast and T6 heat-treated Mg-Al-Zn-X alloys fabricated by the RCM were investigated. The microstructural and mechanical characterizations were performed by utilizing optical microscope, scanning electron microscope, transmission electron microscope, hardness test and ultimate tensile test. The solution and aging treatment time was varied to optimize the T6 heat treatment conditions, and experimental results were discussed. The grain size of Sr containing alloys was refined by increasing Sr content, but the tensile and yield strengths were increased by addition up to 1wt% Sr.