• Title/Summary/Keyword: various heating methods

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Thermal Characteristics of Hybrid Composites for Application to Surfboard (서프보드 적용을 위한 하이브리드 복합재료의 열적 특성)

  • Kim, Yun-Hae;Lee, Jin-Woo;Park, Chang-Wook;Park, Soo-Jeong
    • Journal of Ocean Engineering and Technology
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    • v.28 no.4
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    • pp.351-355
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    • 2014
  • Today, carbon fibers are used as heating elements. Carbon fibers are generally used to reinforce composite materials because they are lightweight and have a high strength and modulus. Carbon fiber reinforced composite materials are used for aerospace, automobile, and wind turbine blade applications. This work explored the possibility of using carbon fiber reinforced composite materials as self heating materials. The temperatures of the carbon fiber reinforced composites were measured. These results verified that the carbon fiber reinforced composite materials could be used as heating elements. A glass fiber was laminated using various methods. The thermal characteristics of the composites were evaluated. This confirmed that the generation of heat varied according to the lamination thicknesses of the carbon fiber and glass fiber. As the number of carbon fiber laminations increased, the heat-generating temperature increased. In contrast, as the number of glass fiber laminations increased, the amount of heat decreased. The generation of heat and ability to remain warm could be controlled by controlling the carbon fiber and glass fiber laminations.

Polypyrrole-Coated Woven Fabric as a Flexible Surface-Heating Element

  • Lee, Jun-Young;Park, Dong-Won;Lim, Jeong-Ok
    • Macromolecular Research
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    • v.11 no.6
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    • pp.481-487
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    • 2003
  • Polypyrrole (PPy) was coated sequentially by chemical and electrochemical methods on a woven fabric, giving rise to a fabric having high electrical conductivity. We investigated the effects of the preparation conditions on the various properties of the resulting fabric. The PPy-coated fabric with optimum properties was obtained when it was prepared sequentially by chemical polymerization at the elevated temperature of 100$^{\circ}C$ under a pressure of 0.9 kgf/$\textrm{cm}^2$ and then electrochemical polymerization with a 3.06 mA/$\textrm{cm}^2$ current density at 25 $^{\circ}C$ for 2 hrs with the separator plate. The surface resistivity of the resulting fabric was as low as 5 Ω/$\square$ .The PPy-coated fabric prepared under the optimum conditions showed practically applicable heat generating property. When electrical power was supplied to the fabric using a commercial battery for a mobile phone (3.6 V, LGLl-AHM), the temperature of the fabric increased very quickly from room temperature to ca. 55 $^{\circ}C$ within 2 min and was maintained for ca. 80 min at that temperature. The heat generating property of the fabric was extremely stable, exhibiting similar behavior over 10 repeated cycles. Therefore, we suggest that the PPy-coated fabric in this study may be practically useful for many applications, including flexible, portable surface-heating elements for medical or other applications.

A Case Report of Postpartum Disease Induced by Inadequate Postpartum Care (잘못된 산후관리로 인한 산후질환 1례 보고)

  • Lee, Jin-Moo;Lee, Chang-Hoon;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub;Kim, Eun-Sook
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.3
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    • pp.238-245
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    • 2007
  • Purpose: In postpartum period, women are very weak and liable to various diseases. So postpartum care is very important. But excessive heating and sweating cause postpartum diseases. Methods: The patient in this case, 37 years-old female was in Kyunghee University East-West neo medical center for 8days(27th/Oct/2006 - 3rd/Nov/2006). Her chief complains when she was admitted in the hospital were sweating, chilling, and mild dizziness. These symptoms were caused by excessive heating and sweating. We thought that her condition was deficiency of Qi. After giving her the therapies with herb medicine, acupuncture and moxibustion, her symptoms got almost disappeared and her condition got better. Results: After the oriental medical treatment, the clinical symptom of postpartum disease was improved. Conclusion: This case study shows that excessive heating and sweating cause postpartum diseases and the oriental medical therapy is effective in treating postpartum disease. And the guideline of postpartum care is needed.

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A Study for the Mechanical and Sensory Characteristics of Mushrooms by various Cooking Methods (조리방법에 따른 버섯의 기계적ㆍ관능적 특성에 관한 연구)

  • 김정숙;한재숙;이재성
    • Korean journal of food and cookery science
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    • v.11 no.1
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    • pp.44-50
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    • 1995
  • In order to investigate the mechanical and sensory characteristics of dried Lentinus edodes, raw Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus by various cooking methods, texture measurements and sensory evaluation were performed. And the results were summarised as follows. Hardness, cohesiveness, springiness, gumminess and chewiness of those mushrooms, except the cohesiveness and springiness of Pleurotus ostreatus head, showed significant differences depending on the cooking methods. Microwave heating of mushrooms, in general, give high values in mechanical characteristics measurements. As a results of sensory evaluation, salt water blanching turned out to be the most preferred cooking method among blanching, steaming, microwave heating. The mushroom dishes were preferred by the panel in the order of Jungol, Hoi, Fritter, Saute and Jun.

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Effect of Microwave and High-temperature Heating Methods on Contaminates Removal from Oil-contaminated Soil by Heat Treatment (유류오염토양의 열처리에서 micro파와 고온발열체 방법이 오염제거에 미치는 영향)

  • Ha, Sang-An;Wang, Jei-Pil
    • Resources Recycling
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    • v.23 no.2
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    • pp.46-52
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    • 2014
  • This study was conducted to observe the removal efficiency of oil-contaminated soil by various tests using microwaves and high-temperature heating elements. The water content was measured with the treatment amount, which was lowered to 300g in a relatively short amount of time. The treatment rate of TPH(Total Petroleum Hydrocarbons) showed the highest value with 70.1% when the SiC-activated carbon heating element was at 4 kW/kg, compared to the SiC heating element used alone. In particular, the higher electric power became, the higher treatment rate became, except at 3 kW. In the case of the heating element made by the fusion of SiC and activated carbon, the internal temperature exceeded $300^{\circ}C$ and again fell when it was treated at 4 kW for about 2 minutes. Then, after about 8 minutes, it rose again. On the basis of such results, the energy content necessary for the sample was calculated according to the electric power of microwaves, and tthe constant of TPH treatment was measured by tests on the treatment characteristics of oil-contaminated soil.

Retention of Ascorbic Acid in Vegetables as Influenced by Various Blanching Methods (여러가지 가열방법에 따른 채소의 Ascorbic Acid 잔존량)

  • 임숙자
    • Korean journal of food and cookery science
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    • v.8 no.4
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    • pp.411-419
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    • 1992
  • Retention of ascorbic acid in vegetables as influenced by various blanching methods was measured and the effects of blanching time, amount of water added, and with or without lid on the retention were compared. It was found that blanching with small amount of water and without lid generally retained the higher activity of ascorbic acid. Although steam blanching showed the highest retention of the vitamin, the longer heating time was needed to blanch the vegetables. Blanching by microwave oven has revealed that addition of small amount of water did not affect the retention. From the scoring difference test for texture of blanched spinach, the samples which were indicated as best in texture by the 8-panel members have retained 73~96% of ascorbic acid and samples blanched by microwave oven for 60 seconds showed highest retention.

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A Simulation of Temperature Control of Greenhouse with Hot-Water Heating System (온수난방시스템 온실의 온도제어 시뮬레이션)

  • 정태상;하종규;민영봉
    • Journal of Bio-Environment Control
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    • v.8 no.3
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    • pp.152-163
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    • 1999
  • It is required to analyze the controlled response of air temperature in greenhouse according to control techniques for precise control. In this study, a mathematical model was established for air heating of greenhouse with hot-water heating system The parameters of the model were decided by regression analysis using reference data measured at the greenhouse being heated In the simulation for the digital control of air temperature in the greenhouse, the mathematical model to evaluate the control performances was used. Tested control methods were ON-OFF contpol, p control, rl control and PID control. The mathematical model represented by inside air temperature ( T$_{i}$), hot-water temperature (T$_{w}$) in heating pipe and outside air temperature (T$_{o}$) was expressed as a following discrete time equation ; T$_{i}$($textsc{k}$+1)= 0.851.T$_{i}$($textsc{k}$)+0.055.T$_{w}$($textsc{k}$)+0.094.T$_{o}$($textsc{k}$) Control simulations for various control methods showed the settling time, the overshoot and the steady state nor as follows; infinite time, 3.5$0^{\circ}C$, 3.5$0^{\circ}C$ for ON-OFF control : 30min 2.37$^{\circ}C$, 0.51$^{\circ}C$ for P control; 21min, 0.0$0^{\circ}C$, 0.23$^{\circ}C$ for PI control; 18min 0.0$0^{\circ}C$, 0.23$^{\circ}C$ for PID control, respectively. PI and PID controls appeared to be optimal control methods. There was no effect of differential gain on the heating process but much effect of integral gain on it.on it.

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Modeling and Experimental Study of Radio-frequency Glow Discharges and Applications for Plasma Processing

  • Kang, Nam-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.179-179
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    • 2012
  • Low pressure radio-frequency glow discharges are investigated using theoretical modeling and various experimental diagnostic methods. In the calculations, global models and transformer models are developed to understand the chemical kinetics as well as the electrical properties such as the effective collision frequency, the heating mechanism and the power transferred to the plasma electrons. In addition, Boltzmann equation solver is used to compensate the effect of the electron energy distribution function (EEDF) shape in the global model, and the general expression of energy balance for non-Maxwellian electrons is developed. In the experiments, a number of traditional plasma diagnostic methods are used to compare with calculated results such as Langmuir probe, optical emission spectroscopy (OES), optical absorption spectroscopy (OAS) and two-photon absorption laser-induced fluorescence (TALIF). These theoretical and experimental methods are applied to understand several interesting phenomena in low pressure ICP discharges. The chemical and physical properties of low pressure ICP discharges are described and the applications of these methods are discussed.

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Conservation Properties of Chalk Added Functional Lining Papers (기능성 배접지의 보존 특성 분석 -호분지-)

  • Choi, Kyoung-Hwa;Park, Ji-Hee;Seo, Jin-Ho
    • 보존과학연구
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    • s.31
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    • pp.79-88
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    • 2010
  • Paper cultural heritages experience chemical and physical deterioration due to various factors including preservation environments and the property of paper materials1). Thus, it is important to develop optimal preservation and restoration methods for the damaged paper cultural heritages. Currently, lining is a popular treatment for the restoration of paper cultural heritages in Korea. Since lining paper is a layer of paper directly attached to the inside of cultural heritages for protection, understanding of the preservation properties of lining paper is primarily needed in order to devise the better preservation methods. The main material of lining paper is the paper mulberry, but additives such as chalk and white clay is sometimes used to enhance the preservation properties of lining paper. To date, the properties of the functional lining paper containing these additives have been not fully understood yet. In this study, dry heating aging at $105^{\circ}C$ and biological aging by the Aspergillus versicolor and Penicillium polonicum for the lining paper, which is made from paper mulberry and the chalk, are carried out to evaluate changes in their preservation properties by these aging factors. As a result, it is found that the functional lining paper containing 25.1% of chalk can control the growth of fungi, while the paper containing 32.7% of chalk do not show any protection effect. However, the functional lining paper added by chalk is more aged than the lining paper made from paper mulberry by dry heating accelerated aging.

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Inhibitory Activity of Advanced Glycation Endproducts (AGEs) Formation and Antioxidant Activity of Processed Korean Medicines (포제한약재의 최종당화산물 생성 억제 활성 및 항산화 효과)

  • Lee, AhReum;Kwon, OJun;Choi, JoonYoung;Roh, Seong-Soo
    • The Korea Journal of Herbology
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    • v.32 no.3
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    • pp.63-69
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    • 2017
  • Objectives : Advanced glycation end product (AGEs) is combine formation of glucose and protein. AGEs and reactive oxygen species are potential therapeutic targets for the various disease such as diabetic complications, renal injury, skin damage. The aim of this study was investigated the AGEs inhibitory activity and antioxidant activity of water extracts from 40 Korean medicines and 5 heating-processed Korean medicines. Methods: AGEs formation inhibitory activities of Korean medicines measured using bovine serum albumin (BSA), glucose, and fructose. Then, five effective Korean medicines were selected and heated with 30% ethanol. The AGEs inhibitory activities of heated Korean medicine were measured compared with not-heated Korean medicines. The antioxidant activities were evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals. Furthermore, we examined total phenol and flavonoids contents. Results: Scutellariae Radix, Corni Fructus, Persimmon Fruit, Paeoniae Radix, Mori Folium respectively reduced AGEs production. Morever, heating-processed Scutellariae Radix has AGEs inhibitory activities better than not-processed Scutellariae Radix. Heating- processed Scutellariae Radix scavenged DPPH and ABTS effectively and $IC_{50}$ of DPPH and ABTS radical scavenging activity of Heat processed Scutellariae Radix were $15.47{\pm}0.26{\mu}g/m{\ell}$ and $12.07{\pm}1.23{\mu}g/m{\ell}$. It caused heat processing methods of Scutellariae Radix up regulated total phenol and flavonoids contents ($26.68{\pm}0.01$ to $46.15{\pm}0.10$, $20.30{\pm}0.38$ to $64.20{\pm}0.52$). Conclusion: It has AGEs inhibitory activities that 20 kind of medicinal plants of 40 medicinal plants. Especially, heat processed Scutellariae Radix has excellent AGEs inhibitory activities and antioxidant effect.