• Title/Summary/Keyword: Heat Stable

Search Result 1,282, Processing Time 0.023 seconds

Investigation of the Temperature Change and Quantity of Heat Stimulus of the Commercial Indirect Moxibustion (상용 간접구의 연소형태와 열자극량에 대한 연구)

  • Kwon, O-Sang;Lee, Sang-Hun;Cho, Sung-Jin;Choi, Kwang-Ho;Choi, Sun-Mi;Ryu, Yeon-Hee
    • Journal of Acupuncture Research
    • /
    • v.28 no.6
    • /
    • pp.139-147
    • /
    • 2011
  • Objectives : In this research, relatively the characteristic in the combustion according to the brands of the commercial indirect moxibustion is compared and the commercial indirect moxibustion is standardized and this result tries to be provided as necessary basic data. Methods : After adhering to the agarose gel surface in which the thermocouple is inserted, 6 kinds of commercial indirect moxibustion were burnt off and the burning behaviour of the commercial indirect device and heat quantity of stimulus was compared. Results : 1. The form of combustion did not have a difference in 6 kinds of commercial indirect moxibustion combustion. 2. As to the miximum temperature, 'Seoam' and 'Dongbang' was higher than 'Baekryoung' and 'Taeyang'. 3. It was long so that the highest temperature reaching time of 'Seoam' could note in comparison with the other brands. And the highest temperature reaching time of 'Baekryoung' was short to note in comparison with the other brands. 4. As to the quantity of heat stimulus, 'Seoam' was the biggest and 'Baekryoung' was the smallest. 5. The quantity of heat stimulus of 'Dongbang' was the most stable. Conclusions : In this research, relatively the form of combustion of 6 kinds of commercial indirect moxibustion and heat quantity of stimulus were compared. It desires to anticipate the result that it makes the skin.

HSP27 EXPRESSION IN OSTEOBLAST BY THERMAL STRESS (골모세포에서 열자극에 의한 Hsp27 발현에 대한 연구)

  • Rim, Jae-Suk;Kim, Byeong-Ryol;Kwon, Jong-Jin;Jang, Hyon-Seok;Lee, Eui-Suk;Jun, Sang-Ho;Woo, Hyeon-Il
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.30 no.1
    • /
    • pp.11-21
    • /
    • 2008
  • Aim of the study: Thermal stress is a central determinant of osseous surgical outcomes. Interestingly, the temperatures measured during endosseous surgeries coincide with the temperatures that elicit the heat shock response of mammalian cells. The heat shock response is a coordinated biochemical response that helps to protect cells from stresses of various forms. Several protective proteins, termed heat shock proteins (hsp) are produced as part of this response. To begin to understand the role of the stress response of osteoblasts during surgical manipulation of bone, the heat shock protein response was evaluated in osteoblastic cells. Materials & methods: With primary cell culture studies and ROS 17/2.8 osteoblastic cells transfected with hsp27 encoding vectors culture studies, the thermal stress response of mammalian osteoblastic cells was evaluated by immunohistochemistry and western blot analysis. Results: Immunocytochemistry indicated that hsp27 was present in unstressed osteoblastic cells, but not fibroblastic cells. Primarily cultured osteoblasts and fibroblasts expressed the major hsp in response to thermal stress, however, the small Mr hsp, hsp27 was shown to be a constitutive product only in osteoblasts. Creation of stable transformed osteoblastic cells expressing abundant hsp27 protein was used to demonstrate that hsp27 confers stress resistance to osteoblastic cells. Conclusions: The demonstrable presence and function of hsp27 in cultured bones and cells implicates this protein as a determinant of osteoblastic cell fate in vivo.

Enhancement of Thermal Insulation Performance with Phase Change Material for Thermal Batteries (상변화 물질을 이용한 열전지 단열성능 향상에 관한 연구)

  • Lee, Jaein;Ha, Sang-hyeon;Kim, Kiyoul;Cheong, Haewon;Cho, Sungbaek
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.19 no.4
    • /
    • pp.469-475
    • /
    • 2016
  • Thermal batteries are primary reserve power sources, which are activated upon the melting of eutectic electrolytes by the ignition of heat sources. Therefore, sufficient thermal insulation is absolutely needed for the stable operation of thermal batteries. Currently, excessive amount of heat sources is being used to compensate the heat loss in the cell stack along with the insertion of metal plates and thermal insulators to reserve heat at the both ends of cell stack. However, there is a possibility that the excessive heat flows into the cell stack, causing a thermal runaway at the early stage of discharge. At the same time, the internal temperature of thermal batteries cannot be maintained above the battery operating temperature at the later stage of discharge because of the insufficient insulation. Therefore, the effects of Phase Changing Material(PCM) plates were demonstrated in this study, which can replace the metal and insulating plates, to improve the thermal insulation performance and safety of thermal batteries.

An Experimental Study on the Heat Transfer Characteristics to Enhance the Artificial Hydrate Formation Performance (전열특성을 이용한 가스하이드레이트 인공제조 성능향상에 대한 실험적 연구)

  • Shin, Chang-Hoon;Park, Seoung-Su;Kwon, Ok-Bae;Shin, Kwang-Sik;Choi, Yang-Mi;Lee, Jeong-Hwan
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2007.06a
    • /
    • pp.515-518
    • /
    • 2007
  • Gas hydrates are ice-like crystalline compounds that form under low temperature and elevated pressure conditions. Recently, gas hydrates present a novel means for natural gas storage and transportation with potential applications in a wide variety of areas. An important property of hydrates that makes them attractive for use in gas storage and transportation is their very high gas-to-sol id ratio. In addition to the high gas content, gas hydrates are remarkably stable. The main barrier to development of gas hydrate technology is the lack of an effective mass production method of gas hydrate in solid form. In this study, some performance comparison among several cases classified by different volume sizes of solution were carried to identify the characteristics due to the volume increment. And it is found that one of the main reasons disturbing hydrate formation is related to the lack of cooling heat transfer due to the volume increase of the solution. So, three kinds of heat transfer plates which have different shapes and cross sectional areas were made and tested for the performance comparison following to the shape and area of each plate. Finally it is clarified that the heat transfer is one of the major factors effecting hydrate formation performance and the installation of heat transfer plate can enhance the formation performance especially not in terms of the quantity but the speed.

  • PDF

Stress-shock Response of a Methylotrophic Bacterium Methylovorus sp. strain SSl DSM 11726

  • Park, Jong H.;Kim, Si W.;Kim, Eungbin;Young T. Ro;Kim, Young M.
    • Journal of Microbiology
    • /
    • v.39 no.3
    • /
    • pp.162-167
    • /
    • 2001
  • Methylovorus sp. strain SS1 DSM 11726 was found to grow continuously when it was transferred from 30$\^{C}$ to 40$\^{C}$ and 43$\^{C}$. A shift in growth temperature from 30$\^{C}$ to 45$\^{C}$, 47$\^{C}$ and 50$\^{C}$ reduced the viability of the cell population by more than 10$^2$, 10$^3$and 10$\^$5/ folds, respectively, after 1h cultivation. Cells transferred to 47$\^{C}$ and 50$\^{C}$ after preincubation for 15 min at 43$\^{C}$, however, exhibited 10-fold increase in viability. It was found that incubation for 15 min at 40$\^{C}$ of Methylovorus sp. strain SSl grown at 30$\^{C}$ was sufficient to accelerate the synthesis of a specific subset of proteins. The major heat shock proteins had apparent molecular masses of 90, 70, 66, 60, and 58 kDA. The 60 and 58 kDa proteins were found to cross-react with the antiserum raised against GroEL protein. The heat shock response persisted for over 1h. The shock proteins were stable for 90 min in the cell. Exposure of the cells to methanol induced proteins identical to the heat shock proteins. Addition of ethanol induced a unique protein with a molecular mass of about 40 kDa in addition to the heat-induced proteins. The proteins induced in paraquat-treated cells were different from the heat shock proteins, except the 70 and 60 kDa proteins.

  • PDF

CRITICAL HEAT FLUX ENHANCEMENT IN FLOW BOILING OF Al2O3 AND SiC NANOFLUIDS UNDER LOW PRESSURE AND LOW FLOW CONDITIONS

  • Lee, Seung-Won;Park, Seong-Dae;Kang, Sa-Rah;Kim, Seong-Man;Seo, Han;Lee, Dong-Won;Bang, In-Cheol
    • Nuclear Engineering and Technology
    • /
    • v.44 no.4
    • /
    • pp.429-436
    • /
    • 2012
  • Critical heat flux (CHF) is the thermal limit of a phenomenon in which a phase change occurs during heating (such as bubbles forming on a metal surface used to heat water), which suddenly decreases the heat transfer efficiency, thus causing localized overheating of the heating surface. The enhancement of CHF can increase the safety margins and allow operation at higher heat fluxes; thus, it can increase the economy. A very interesting characteristic of nanofluids is their ability to significantly enhance the CHF. Nanofluids are nanotechnology-based colloidal dispersions engineered through the stable suspension of nanoparticles. All experiments were performed in round tubes with an inner diameter of 0.01041 m and a length of 0.5 m under low pressure and low flow (LPLF) conditions at a fixed inlet temperature using water, 0.01 vol.% $Al_2O_3$/water nanofluid, and SiC/water nanofluid. It was found that the CHF of the nanofluids was enhanced and the CHF of the SiC/water nanofluid was more enhanced than that of the $Al_2O_3$/water nanofluid.

Flammability and Thermal Stabilities of Heat Transfer Oils (열매체유의 인화성과 열안정성)

  • Lee, Keun-Won;Lee, Jung-Suk;Choi, Yi-Rac
    • Journal of the Korean Institute of Gas
    • /
    • v.15 no.2
    • /
    • pp.82-87
    • /
    • 2011
  • Heat transfer oils are used in applications such as heating systems of chemical plant, refinery heat exchange systems, gas plant process, injection molding systems, and pulp and paper processing. These oils are extremely stable and resistance to thermal and oxidative degradation. In the event of a spill or accidental release of heat transfer oils, it can be ignite easily when there is an ignition source. This paper discusses the flammability and thermal stabilities of new and used oils. The flammability of the oils are assessed by measuring changes in flash point and auto ignition temperature. The thermal stability of oils are evaluated by the thermal screening unit ($TS^u$) and the differential scanning calorimeter (DSC). From the experimental results, it is suggested to give fire hazard characteristics to safe precautions for the proper use and treatment of heat transfer oils.

Evaluation on Cooling Performance of Ground Source Heat Pump System Equipped with Steel-pipe Civil Structures (강관 토목구조물이 설치된 지열 히트펌프 시스템의 냉방 성능 평가)

  • Seokjae Lee;Jeonghun Yang;Hangseok Choi
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.19 no.3
    • /
    • pp.14-22
    • /
    • 2023
  • Steel-pipe civil structures, including steel-pipe energy piles and cast-in-place piles (CIPs), utilize steel pipes as their primary reinforcements. These steel pipes facilitate the circulation of a working fluid through their annular crosssection, enabling heat exchange with the surrounding ground formation. In this study, the cooling performance of a ground source heat pump (GSHP) system that incorporated steel-pipe civil structures was investigated to assess their applicability. First of all, the thermal performance test was conducted with steel-pipe CIPs to evaluate the average heat exchange amount. Subsequently, a GSHP system was designed and implemented within an office container, considering the various types of steel-pipe civil structures. During the performance evaluation tests, parameters such as the coefficient of performance (COP) and entering water temperature (EWT) were closely monitored. The outcomes indicated an average COP of 3.74 for the GSHP system and the EWT remained relatively stable throughout the tests. Consequently, the GSPH system demonstrated its capability to consistently provide a sufficient heat source, even during periods of high cooling thermal demand, by utilzing the steel-pipe civil structures.

Studies on the Production of Watermelon and Cantaloupe Melonjuice (수박 및 참외 쥬스 제조에 대하여)

  • Shin, Dong-Hwa;Koo, Young-Jo;Kim, Choung-Ok;Min, Byong-Yong;Suh, Kee-Bong
    • Korean Journal of Food Science and Technology
    • /
    • v.10 no.2
    • /
    • pp.215-223
    • /
    • 1978
  • In Korea, the annual production of watermelon and cantaloupe melon is around 110,000 to 170,000 Metric Tons, and as the fruit does not keep well, studies were conducted to determine the feasibility of preservation in the form of natural juice or lactic fermented juice. The results obtained in these studies are summarized as follows: (1) The average yield of juice obtained from watermelon was 56.2%, and from cantaloupe melon 65.8%, of the fresh weight. (2) The colloidal components of watermelon juice separated from the juice by sedimentation within 24 hours. Cantaloupe melon juice gave a stable colloidal dispersion. (3) No change in the colour of the juices was detected by sensory evaluation or instrumental methods after they were treated at $100^{\circ}C$ for 5 minutes. (4) The addition of canesugar to give a total solids content of 11/13 Brix gave juices which were preferred by most tasters. (5) Lactic fermentation of natural juices pasteurised at $90^{\circ}C$ for 5 minutes, and inoculated with a pure culture of lactic acid bacteria proceeded without interference from competing microorganisms. (6) Sensory evaluation of lactic fermented juices indicated that 60% of tasters found the juices as acceptable or better than commercial fruit nectars at present on the market. (7) Taste panels showed a preference for natural melon juices over the lactic fermented juices. (8) The peroxidase activity of cantaloupe melon juice was higher than that of watermelon juice, with juice extracted from the core of the fruit showing a higher activity than that from other portions of the tissue. (9) Two types of peroxidase, of differing heat stability were detected in both juices. The more heat stable peroxidase had a decimal reduction time of 40 minutes at $80^{\circ}C$ and a z value of $11^{\circ}C$.

  • PDF

Influence of the Relative Amount of Graphite and Zirconium Silicate on Friction Characteristics (흑연과 지르콘의 상대적인 함량에 따른 마찰특성에 관한 연구)

  • Kim, Seong-Jin;Jang, Ho
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2000.06a
    • /
    • pp.166-172
    • /
    • 2000
  • Friction characteristics of phenolic resin-based friction composites containing threedifferent relative amounts of graphite and zirconium silicate were investigated by using a pad-on-disk type friction tester. Constant temperature test and constant interval test at three different initial temperatures(100. 200, 300$^{\circ}C$) were performed to examine the effects of friction heat on friction characteristics at elevated temperature. The friction composite(FMO.7) with higher content of ZrSiO$_4$showed unstable friction force at higher temperature and resulted in larger fluctuations of vibration during friction test. The abrasive action of ZrSiO$_4$in friction composite impeded stable transfer film and induced higher friction heat at friction interface. Friction oscillations according to the temperature were associated with the formation of transfer film(i'd body layer) on the friction composite and the counter part.

  • PDF