• 제목/요약/키워드: thermal treatment

검색결과 2,703건 처리시간 0.035초

Effect of Thermal Treatment Temperature on Lifespan of Conductive Oxide Electrode

  • Yoo, Y.R.;Chang, H.Y.;Jang, S.G.;Nam, H.S.;Kim, Y.S.
    • Corrosion Science and Technology
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    • 제6권2호
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    • pp.44-49
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    • 2007
  • Dimensionally stable anodes have been widely used to cathodically protect the metallic materials in corrosive environments including concrete structure as the insoluble anode. Lifespan of the anode for concrete construction can be determined by NACE TM0294-94 method. Lifespan of conductive oxide electrode would be affected by thermal treatment condition in the process of sol-gel coatings. This work aims to evaluate the effect of thermal treatment temperature on the lifespan of the $RuO_{2}$ electrode. $450^{\circ}C$ treated conductive oxide electrode showed the excellent properties and its lifespan was evaluated to be over 88 years in 3% NaCl, 4% NaOH, and simulated pore water. This behavior was related to the formation of $RuO_{2}$.

열처리 조건에 따른 비닐절연전선의 특성 변화 (Characteristics of Vinyl Insulated Wire with Thermal Treatment Conditions)

  • 최충석;박창수;송길목;이경섭;이덕출
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1401-1403
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    • 1998
  • The composition, weight decrease, DTA, and surface structure of vinyl insulated wire with thermal treatment conditions have been investigated. The composition of Cu by EDX analysis indicates Cu, Cl, and O lines, and oxidation reaction results from thermal treatment. Thermal treated IV and HIV appeared chemical reaction at $269^{\circ}C$ and $265^{\circ}C$, respectively. SEM of thermal treated Cu at $250^{\circ}C$ disappears an elongation structure, and appears an original structure.

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가지 열수추출물의 피부생리활성에 관한 연구 (A Study of Physiological Activities of the Thermal Treated Eggplant on the Skin)

  • 김란
    • KSBB Journal
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    • 제31권3호
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    • pp.151-157
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    • 2016
  • The purpose of the present research was to investigate the physiological activities of the thermal treated eggplant on the skin. Five minute of thermal treatment at $100^{\circ}C$ had the highest polyphenol content of eggplant. However, below and over 5 min of thermal treatment time, they did not increase. When water and ethanol extracts were used, the maximum DPPH radical scavenging activities were obtained, 66.3 and 62.8%, respectively. Among various extracts, the acetone extract gave the highest cosmetic activity. Especially, when acetone extract (15.0 mg/mL) was used, the maximum inhibition activities of tyrosinase, elastase, and collagenase were obtained, 83.4, 78.2 and 62.5%, respectively. These results suggest the anti-wrinkle and whitening and effects of acetone extract were excellent. Therefore, it is should be considered as a promising candidate for novel cosmetic agents.

인코넬 690의 강화기구에 관한 연구 (On the Strengthening mechanisms of INCONEL 690)

  • 허무영;박용수;안성욱
    • 소성∙가공
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    • 제6권3호
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    • pp.213-220
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    • 1997
  • The microstructure of the inconel 690 alloy was varied by the solution treatment and the thermal treatment. The specimens having different microstructures were examined in order to understand the strengthening mechanism of the inconel 690. The level of supersaturation of carbon in the solid solution was increased by applying a longer solution treatment at 115$0^{\circ}C$. As increased carbon content in the solid solution, more carbides precipitated during the thermal treatment at $700^{\circ}C$. Since the carbides played a role of obstacle on the movement of dislocations, a higher tensile strength was obtained in the sample having a large number of carbider. The accumulation of dislocations at the grain boundary carbides caused the development of intergranular fracture which led to a lower elongation.

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Effects of Flux Treatment on the Glass Forming Ability and Magnetic Properties of Fe-based Ternary Amorphous Alloys

  • Zuo, Mingqing;Yi, Seonghoon
    • 한국주조공학회지
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    • 제40권4호
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    • pp.113-117
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    • 2020
  • A series of Fe-P-B and Fe-Si-B amorphous alloys with high Fe contents exceeding 90 wt.% was successfully prepared by combining flux treatment and melt-spinning technique. The effects of Fe content and the flux treatment on the thermal and magnetic properties of amorphous alloys were studied. The glass-forming ability and the thermal stability of amorphous ribbons can be improved by a flux treatment, revealing the effective removal of heterogeneous nucleation sites in the ribbons through the flux treatment. It was found that Fe-Si-B ribbons exhibit higher saturation magnetization levels than Fe-P-B ribbons.

저온 태양열 이용 생물학적 오수 처리 (Biological Waste Water Treatment with Solar Thermal Energy)

  • 정모;이동원;김정배;윤응상;변무룡;변무원
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.559-562
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    • 2006
  • A low-temperature solar thermal system assisting a biological nitrogen treatment reservoir was designed and field-tested. A large tank whose temperature was maintained at about $25{\sim}30^{\circ}C$ to enhance the performance of a biological nitrogen treatment process was heated by an array of flat plate solar collectors. Test results revealed that the overall collector efficiency was above 50% for the most cases tested. This high efficiency was possible owing to the relatively low collector temperature that can be traced back to the reservoir temperature. A substantial enhancement in nitrogen treatment was observed as a result of maintaining the reservoir temperature higher.

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저밀도 폴리에틸렌의 결정화도에 대한 저온 열처리 효과: 수소 핵자기공명 연구 (Effect of Low-temperature Thermal Treatment on Degree of Crystallinity of a Low Density Polyethylene: $^{1}H$ Nuclear Magnetic Resonance Study)

  • 이창훈;최재곤
    • Elastomers and Composites
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    • 제43권4호
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    • pp.259-263
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    • 2008
  • 저밀도 폴리에틸렌에 대한 장시간 저온 열처리가 저밀도 폴리에틸렌 고분자의 결정화도에 미치는 효과를 고체 수소 핵자기공명을 이용하여 연구하였다. 장시간 열처리는 첫째, 저밀도 폴리에틸렌의 색깔을 엷은 노란색으로 변하게 하였고 둘째, 저밀도폴리에틸렌에서 수소 핵의 스핀-스핀 및 스핀-격자 완화시간을 증가시켰으며, 셋째, 결정화도를 줄어들게 하였다. 먼저, $T_1$의 증가를 저밀도폴리에틸렌의 전체 스핀-격자 완화시간을 결정하는 비정질 영역의 부피 감소에 의한 것이거나 분자간 가교나 수소결합에 의한 특정 분자 운동 성분의 느려짐에 의해 발생하는 것으로 고려하였다. 하지만 결정화도의 감소는 열처리에 의한 비정질 영역의 감소를 의미하므로 전자와는 배치되었다. 따라서 $T_1$의 증가는 후자에 의한 결과임을 알 수 있었다.

표면처리 및 윤활제에 따른 열간 단조 금형의 수명 평가 (Die Life Estimation of Hot Forging for Surface Treatment and Lubricants)

  • 이현철;김병민;김광호
    • 한국정밀공학회지
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    • 제20권7호
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    • pp.26-35
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    • 2003
  • This study explains the effects of lubricant and surface treatment on hot forging die life. The mechanical and thermal load, and thermal softening which is happened by the high temperature of die, in hot and warm forging, cause die wear, heat checking and plastic deformation, etc. This study is fur the effects of solid lubricants and surface treatment condition for hot forging die. Because cooling effect and low friction are essential to the long life of dies, optimal surface treatment and lubricant are very important to improve die life for hot forging process. The main factors, which affect die hardness and heat transfer, are surface treatments and lubricants, which are related to thermal diffusion coefficient and heat transfer coefficient, etc. For verifying these effects, experiments are performed for hot ring compression test and heat transfer coefficient in various conditions as like different initial billet temperatures and different loads. The effects of lubricant and surface treatment for hot forging die life are explained by their thermal characteristics. The new developed technique in this study for predicting tool life can give more feasible means to improve the tool life in hot forging process.

Treatment of Refractory Melasma with Microwave-generated, Atmospheric-pressure, Non-thermal Nitrogen Plasma

  • Kim, Hyun-Jo;Kim, Heesu;Kim, Young Koo;Cho, Sung Bin
    • Medical Lasers
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    • 제8권2호
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    • pp.74-79
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    • 2019
  • Periorbital melasma is often refractory to treatment and highly associated with rebound hyperpigmentation or mottled hypopigmentation after laser treatment in Asian patients. In this report, we describe 2 patients with cluster-1 periorbital melasma and 1 patient with cluster-2 periorbital melasma who experienced remarkable clinical improvements after microwave-generated, atmospheric-pressure, non-thermal nitrogen plasma treatments. All patients exhibited limited clinical responses after combination treatments with topical bleaching agents, systemic oral tranexamic acid, and low-fluenced Q-switched neodymium (Nd):yttrium-aluminum-garnet (YAG) lasers. Low-energy nitrogen plasma treatment at 0.75 J elicited remarkable clinical improvement in the periorbital melasma lesions without post-laser therapy rebound hyperpigmentation and mottled hypopigmentation. We deemed that a single pass of nitrogen plasma treatment at 0.75 J induces mild microscopic thermal tissue coagulation and modification within the epidermis while preserving the integrity of the basement membrane in patients with periorbital melasma. Accordingly, nitrogen plasma-induced dermal tissue regeneration could play a role in the treatment of melasma lesions.

Chemical Composition of Thermal Treatment Yam (Dioscorea batatas DECNE.)

  • Kim, Han-Soo;Duan, Yishan;Ryu, Jae-Young;Kim, Sang-Woo;Jang, Seong-Ho
    • 한국응용과학기술학회지
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    • 제32권1호
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    • pp.7-15
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    • 2015
  • In this study, the thermal treatment yam (Dioscorea batatas DECNE.) was analyzed for its proximate and nutritional compositions including mineral, vitamin, amino acids and fatty acids. Thermal treatment yam is mainly consisted of carbohydrate (70.3%) with small amounts of crude protein (15.8%), crude ash (5.1%) and crude fat (1.6%). It was found to be a good source of essential minerals such as K (1100.2 mg/100 g), Mg (99.4 mg/100 g), Ca (54.8 mg/100 g) and Na (44.9 mg/100 g) but Zn (4.8 mg/100 g) and Fe (0.2 mg/100g) content was low. Little amounts of vitamin E (8.3 mg/100g), vitamin C (3.5 mg/100g) and vitamin B1 (2.1 mg/100g) could be found. The amino acid analysis revealed that the yam was superior with respect to serine (1454.2 mg%), lysine (684.6 mg%) and histidine (684.6 mg%). Essential amino acids were calculated to be 2849.3 mg%. The amino acid profiles showed that thermal treatment yam is limiting in isoleucine and phenylaline. Linoleic acid was the most predominant fatty acids with the value of 47.3% followed by palmitic acid (24.7%) and oleic acid (12.7%). And the unsaturated fatty acids including oleic acid and linoleic acid were present in big quantities in thermal treatment yam.