• Design & Manufacturing
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• v.8 no.2
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• pp.23-29
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• 2014

Salt bath heat treatment is usually used but recently vacuum heat treatment is increased for the heat treatment of hot work die steels. The differences in two heat treatment processes were compared by testing the mechanical properties of heat treated products. With two different features of processes, mechanical properties such as hardness, tensile strength and impact strength of products show very different results. In this study salt bath heat treated products showed higher tensile strength and impact strength than vacuum heat treated products but hardness was not much different. These lower mechanical properties of vacuum heat treated products are due to differences in heating and quenching process.

• Textile Coloration and Finishing
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• v.24 no.3
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• pp.173-179
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• 2012

Silk fabric treated with fluorocarbon resins (Asahi Guard AG-7005 and AG-E061) were washed and subsequently heat treated varying the washing cycles and the temperature. After the processing, the water and oil repellencies, and contact angle to water were evaluated. The water and oil repellencies decreased by the washing and recovered by following heat treatment. Also ESCA measurement was carried out to investigate the surface chemical composition of the treated fiber. The $F_1s$ intensity of the treated fabric decreased by the washing and recovered by the subsequent heat treatment. On the other hand, the $O_1s$ intensity increased by the washing and decreased by following heat treatment. From the results, it is clear that change of the water and oil repellencies of the silk fabric treated with fluorocarbon resin occurred by the washing and subsequent heat treatment. Considering a change of the water repellency of the silk fabric treated with fluorocarbon resin, it seems likely that the fluoroalkyl group of the fluorocarbon resin rotates from surface to inside of the fiber by the washing to adapt to the hydrophilic circumstance, and the orientation of the fluoroalkyl groups of the resin disturbed by the washing recovers the orientation to the fiber surface after the subsequent heat treatment.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.98-112
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• 2020

There is a strong connection between the diet rich in antioxidants and the decreased incidence of inflammatory bowel disease and cancerous diseases. Diets that are rich in anti-oxidants particularly include fruits and vegetables containing the high amounts of vitamin A-E, carotenoids, and minerals. The supercritical heat-treated radish extracts of the research result had an inhibitory effect on the development of aberrant crypt foci (ACF), namely, preneoplastic lesions having a potential to become cancer cells and reduced the number of the aberrant crypt foci (ACF) consisting of four or more aberrant crypts (AC) having high risk to become tumors by about half. The supercritical heat-treated radish extracts can reduce the incidence of preneoplastic lesions having a high risk of developing cancer by about 28 %. DSS-treated mice developed symptoms similar to those of human UC, such as severe bloody diarrhea and weight loss. Supercritical heat-treated radish extracts, as well as sulfasalazine, suppressed colonic length and mucosal inflammatory infiltration. In addition, supercritical heat-treated radish extracts treatment significantly reduced the expression of pro-inflammatory signaling molecules through suppression both mitogen-activated protein kinases (MAPK) and nuclear factor-kappa B (NF-kB) signaling pathways, and prevented the apoptosis of colon. Moreover, supercritical heat-treated radish extracts administration significantly led to the up-regulation of anti-oxidant enzyme including SOD and Catalase.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.193-201
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• 2006

Thermal performance model was developed for a cross-flow aluminum heat exchanger with relatively short passage. Appropriate heat transfer coefficient and friction factor equations for laminar channel flow were obtained considering developing regions. The heat exchanger was analyzed using the unmixed cross-flow ${\epsilon}$-NTU relationship considering leak-age between streams. Thermal contact between corrugations and plates was also considered. Tests were separately conducted for two samples - one made of non-treated aluminum sheets, and the other made of varnish-treated ones. The samples were made by stacking corrugations and plates one after another. The model adequately predicted the thermal performance and pressure drop of the non-treated heat exchanger. The thermal performance of the varnish-treated one was $7{\sim}12%$ overpredicted, and the pressure drop of the varnished-treated heat exchanger was $5{\sim}15%$ underpredicted. The air leakage ratio of the non-treated heat exchanger was $23{\sim}26%$. The ratio decreased to less than $10%$ with the varnish treatment.

• Textile Coloration and Finishing
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• v.20 no.6
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• pp.87-91
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• 2008

It is commonly known that water repellency of the fabric treated with fluorocarbon resin brings about a decrease by the washing and recovers by the subsequent heat treatment. In this article, effect of the water repellency was investigated on the nylon 6, triacetate and silk fabrics treated with hydrocarbon and silicon resins. Hydrocarbon and silicon resins have been widely used in the textile finishing as the softening and water proofing agents. The fabrics were treated with hydrocarbon resins, Paragium JQ and RC (Ohara Paragium Chemical Co.) and a silicon resin, Poron MR (Shinetsu Chemical Co.), and then washed and subsequently heat treated. Although the water repellency increased by the resin treatment, it decreased by the washing apparently and recovered a little by the heat treatment. The effect of the heat treatment was small comparing with that of the fluorocarbon resin. Furthermore, as a mechanical property of the treated fabric, KES shearing and bending hysteresis parameters, modulus and hysteresis width of the hydrocarbon resin-treated nylon 6, triacetate and silk fabrics decreased by the heat treatment after washing. Therefore, the treatment is effective at improving the softening of the fabric in water repellent finish.

• Journal of Powder Materials
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• v.24 no.3
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• pp.216-222
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• 2017

Synthesized monocrystalline nanodiamond (nD) particles are heat-treated at various temperatures to produce highly structured diamond crystals. The heat-treated nDs show different weight loss ratios during thermogravimetric analysis. The crystallinities of the heat-treated nDs are analyzed using Raman spectroscopy. The average particle sizes of the heat-treated nDs are measured by a dynamic light scattering (DLS) system and direct imaging observation methods. Moreover, individual dispersion behaviors of the heat-treated nD particles are investigated based on ultrasonic dispersion methods. The average particle sizes of the dispersed nDs according to the two different measurement methods show very similar size distributions. Thus, it is possible to produce highly crystallized nD powder particles by a heat-treatment process, and the nD particles are relatively easy to disperse individually without any dispersant. The heat-treated nDs can lead to potential applications such as in nanocomposites, quantum dots, and biomedical materials.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.588-595
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• 2016

This paper is a study on head bolts that are used in A/C compressors to reduce production cost and solve leak problems on the head bolt seat area that causes massive intermittent malfunctioning during production. In this study, the pre-heat treated steel, which was used as a material in the head bolt, eliminated the heat treatment process after forging. The pre-heat treated steel head bolts, which have 10 % lower tensile strength than the conventional SCM 435 head bolts, were selected after considering the results of creeping rupture properties, axial force, and stress concentration per tensile strength variation. Then, the performance test and the durability test with the A/C compressor that was assembled with the pre-heat treated steel head bolts were performed and verified. Based on the results, the pre-heat treated steel head bolts developed in this study saved 7.3 % in production cost by eliminating the heat treatment process and the logistics process. Furthermore, the leak problem on the head bolt seat area in the A/C compressor was addressed significantly on the mass production assembly line.

• Journal of Power System Engineering
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• v.7 no.4
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• pp.55-60
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• 2003

This paper is to investigate the fatigue crack growth of plasma-sprayed coating steels according to heat treatments. The experimental materials are carbon steels(substrate: S45C) with plasma-sprayed coating layers of Ni-4.5%Al and $TiO_2$. The fatigue test is conducted on compact tension specimen by a servo-hydraulic fatigue testing machine. The specimens are heat-treated at $400^{\circ}C\;and\;800^{\circ}C$, respectively. Loading condition is a constant amplitude sinusoidal wave with a frequency of 10Hz and a load ratio of 0.1. The fatigue crack growth length is automatically measured by a compliance method. In the case of non-heat treated specimens, the fatigue crack growth rates of both substrate and coating specimen are almost same. The crack growth rates of substrates and coating steels by heat treatment are larger than those of the non-heat treated one, because the ductile property increase by heat treatment. In ${\Delta}K<18MPa{\cdot}m^{1/2}$, the crack growth rates of the heat-treated specimens are slightly taster than non-heat treated one. But the both heated and non-heated one are almost same in ${\Delta}K>18MPa{\cdot}m^{1/2}$.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.293-295
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• 1987

This paper deals with the dielectric properties dielectric breakdown strength and mechanical tensile properties according to heat - treatment condition of polyurethane resin. This resin is heat - treated over a range of temperature from $50^{\circ}C$ to $150^{\circ}C$. It is shown that the dielectric dissipation factor decreases with increase of heat - treatment temperature of the sample exept for the sample heat - treated at $150^{\circ}C$. The maximum dielectric breakdown strength is appeared for the sample heat - treated for 10 hours at $100^{\circ}C$, after curing for 24 hours at room temperature. The optimal heat - treatment condition in the view point of the electrical and mechanical properties is appeared for the sample heat - treated for 10 hours at $100^{\circ}C$, after curing for 24 hours at room temperature.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.183-190
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• 2013

Mistletoe (Viscum album) has been widely used as a functional food material for various therapeutic purposes from ancient time. In this study, we examined anti-diabetic and cytotoxic activities of heated-treated mistletoe and the effects of gamma-irradiation on its activities. Heat-treated mistletoe extract was prepared by heating during different time (3, 6, 9 and 12 h) and gamma-irradiated with different doses of 0, 10, 30, 50, 70 and 100 kGy. Heat-treated mistletoe extracts showed a concentration-dependent cytotoxicity on rat insulinoma RINm5F cells and the effect was gradually decreased as heating time increased up to 12 h. 12 h heat-treated extract was no cytotoxic. Gamma-irradiation enhanced the reduction of heat-treated mistletoe-induced cytotoxicity and the decreasing effect was an irradiating dose-dependent. In particular, all of 70 kGy irradiated and heat-treated mistletoe extracts did not showed the cytotoxicity and the effect was comparable to 12 h heat-treated mistletoe extract. Among those extracts, 3 h heat-treated mistletoe extract gradually increased the insulin secreting activity by gamma-irradiation and the effect was the best at 70 kGy, whereas 12 heat-treated extract was no effect. On the test of ${\alpha}$-glucosidase inhibitory activity, 3 h heat-treated mistletoe extract showed the concentration dependent effects and gamma-irradiation induced more activity at 70 kGy, compared to non-irradiated 3 h and 12 h heated mistletoe extracts. These results suggest that the combination of heat treatment and gamma-irradiation might be more effective than only heat-treatment for improving the anti-diabetic activity of mistletoe extract and reducing its cytotoxicity.