• 제목/요약/키워드: Low temperature treatment

검색결과 1,963건 처리시간 0.025초

Effect of hypoosmotic and thermal stress on gene expression and the activity of antioxidant enzymes in the cinnamon clownfish, Amphiprion melanopus

  • Park, Mi-Seon;Shin, Hyun-Suk;Choi, Cheol-Young;Kim, Na-Na;Park, Dae-Won;Kil, Gyung-Suk;Lee, Je-Hee
    • Animal cells and systems
    • /
    • 제15권3호
    • /
    • pp.219-225
    • /
    • 2011
  • We studied oxidative stress in cinnamon clownfish exposed to hypoosmotic (35 psu ${\rightarrow}$ 17.5 psu and 17.5 psu with prolactin (PRL)) and low temperature ($28^{\circ}C{\rightarrow}24^{\circ}C$ and $20^{\circ}C$) conditions by measuring the expression and activity of Cu/Zn-superoxide dismutase (Cu/Zn-SOD), catalase (CAT), and glutathione peroxidase (GPX). The expression and activity of the antioxidant enzymes were significantly higher after the fish were exposed to $24^{\circ}C$, $20^{\circ}C$, and 17.5 psu, and expression was repressed by PRL treatment. Furthermore, we measured $H_2O_2$ and lipid peroxidation levels and found that they were significantly higher after exposure to the hypoosmotic and low-temperature environments. Additionally, we investigated changes in plasma AST and ALT levels after exposure to low temperature and hypoosmotic stress. These levels increased upon exposure of the clownfish to $24^{\circ}C$, $20^{\circ}C$, and 17.5 psu, but the levels of these parameters decreased in the 17.5 psu with PRL treatment during a salinity change. The results indicate that hypoosmotic and low-temperature conditions induce oxidative stress in cinnamon clownfish and that the parameters tested in this study may be indices of oxidative stress in the cinnamon clownfish.

요통치료에서 보법의 영향 (The Influence of Walking on Low Back Pain)

  • 박서희;장상철;나삼식;안훈모
    • 대한의료기공학회지
    • /
    • 제14권1호
    • /
    • pp.63-82
    • /
    • 2014
  • This study is aimed to verify effects of Walking in treating hospitalized patients with low back pain in the Korean medicine hospital. The method of this study is choosing patients whose chief complaints were low back pain in the Korean medicine hospital in Gyeonggi Province. People who agreed to take Walking treatment were classified into experimental group and control group. Both experimental group and control group were treated with Korean medicine. In addition, experimental group performed Walking program more often. Changes of temperature difference taken by digital infrared thermal imaging(DITI) were used as measuring tools. The summary of this study's result is as in the following. There was significant difference in the experimental group which performed Walking treatments but not in the control group resulting from examining the change of temperature difference between left and right Yongchon. As known from the results above, Walking program is meaningful in curing the low back pain.

수족, 하복부 냉증 환자의 치험 1례 (A Case Report of Cold Hypersensitivity of Hands, Feet and Low Abdomen)

  • 윤영진;이진무;이창훈;장준복;이경섭;황덕상
    • 대한한방부인과학회지
    • /
    • 제27권1호
    • /
    • pp.185-192
    • /
    • 2014
  • Purpose: The purpose of this study is to report the effect on cold hypersensitivity of hands, feet and low abdomen by Sasang constitutional treatment. For this purpose, the effects of a treatment were measured quantitatively using Digital Infrared Thermographic Imaging (DITI). Methods: It was a case of report, the patient was a 25-year-old female whose chief complaint was cold hypersensitivity of hands and feet and low abdomem. We treated the patient with Sasang constitutional treatment, and the effect of a treatment was evaluated by DITI. Results: After Sasang constitutional treatment, the differences of temperature of hands, feet and low abdomem were decreased on DITI screening, respectively. Conclusions: Sasang constitutional treatment on cold hypersensitivity of hands, feet and low abdomen is effective. Further studies on diagnosis tools of low abdomen cold hypersensitivity are needed.

TTT/CCT 데이터를 이용한 저합금강의 죠미니 경화능 곡선 계산 (Calculation of Jominy Hardenability Curve of Low Alloy Steels from TTT/CCT data)

  • 정민수;손윤호
    • 열처리공학회지
    • /
    • 제32권1호
    • /
    • pp.17-28
    • /
    • 2019
  • Jominy hardenability curves of low alloy steel containing less than 5 wt.% of alloying elements in total were calculated by applying Scheil's rule of additivity to pre-calculated isothermal transformation curve. Isothermal transformation curve for each phase in steel was approximated as a simple mathematical equation by using Kirkaldy's approach and all coefficients in the equation were estimated from experimental temperature-time-transformation (TTT) and/or continuous cooling transformation (CCT) data in the literature. Then jominy test with simple boundary conditions was performed in computer by applying the finite difference scheme. The resultant cooling curves at each location along a longitudinal direction of Jominy bar were applied to calculate phase fractions as well as mechanical properties such as micro Vickers hardness. The simulated results were compared with experimental CCT data and Jominy curves in the literature.

초극저탄소 Cu강화형 자동차용 강판 변형시효에 미치는 Aluminum 및 고용질소의 영향 (Effect of Aluminum and Solute N on the Strain Aging of Extremely Low-Carbon Automotive Steel Strengthened with Cu sulfide)

  • 홍문희;양혜미;송승우;한성호
    • 대한금속재료학회지
    • /
    • 제47권2호
    • /
    • pp.71-78
    • /
    • 2009
  • The precipitation behavior of solute carbon and nitrogen strongly affects the mechanical properties of low-carbon automotive panel. In the present study, the effects of aluminum and solute nitrogen on the bake hardenability and strain aging of extremely low-carbon steel with carbon content below 15 ppm has been investigated. The ferrite grain size and distribution of precipitates were varied with the amount of aluminum content of 0.003 to ~ 0.100 wt% in a constant solute carbon and nitrogen. With increasing the aluminum content, the ferrite grain size is increased and strain aging is delayed. The strain aging is also delayed by increasing the annealing temperature, although the ferrite grain size is not much changed.

초음파 비선형파라미터를 이용한 무산소동 저주기피로와 2.25Cr 페라이트강의 등온열화 평가 (Characterization of Low-cycle Fatigue of Copper and Isothermal Aging of 2.25Cr Ferritic Steel by Ultrasonic Nonlinearity Parameter)

  • 김정석
    • 열처리공학회지
    • /
    • 제35권5호
    • /
    • pp.239-245
    • /
    • 2022
  • The purpose of this study is to evaluate the degree of microstructural change of materials using ultrasonic nonlinear parameters. For microstructure change, isothermal heat-treated ferritic 2.25Cr steel and low-cycle fatigue-damage copper alloy were prepared. The variation in ultrasonic nonlinearity was analyzed and evaluated through changes in hardness, ductile-brittle transition temperature, electron microscopy, and X-ray diffraction tests. Ultrasonic nonlinearity of 2.25Cr steel increased rapidly during the first 1,000 hours of deterioration and then gradually increased thereafter. The variation in non-linear parameters was shown to be coarsening of carbides and an increase in the volume fraction of stable M6C carbides during heat treatment. Due to the low-cycle fatigue deformation of oxygen-free copper, the dislocation that causes lattice deformation developed in the material, distorting the propagating ultrasonic waves, and causing an increase in the ultrasonic nonlinear parameters.

Effects of Inlet Turbulence Conditions and Near-wall Treatment Methods on Heat Transfer Prediction over Gas Turbine Vanes

  • Bak, Jeong-Gyu;Cho, Jinsoo;Lee, Seawook;Kang, Young Seok
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제17권1호
    • /
    • pp.8-19
    • /
    • 2016
  • This paper investigates the effects of inlet turbulence conditions and near-wall treatment methods on the heat transfer prediction of gas turbine vanes within the range of engine relevant turbulence conditions. The two near-wall treatment methods, the wall-function and low-Reynolds number method, were combined with the SST and ${\omega}RSM$ turbulence model. Additionally, the RNG $k-{\varepsilon}$, SSG RSM, and $SST_+{\gamma}-Re_{\theta}$ transition model were adopted for the purpose of comparison. All computations were conducted using a commercial CFD code, CFX, considering a three-dimensional, steady, compressible flow. The conjugate heat transfer method was applied to all simulation cases with internally cooled NASA turbine vanes. The CFD results at mid-span were compared with the measured data under different inlet turbulence conditions. In the SST solutions, on the pressure side, both the wall-function and low-Reynolds number method exhibited a reasonable agreement with the measured data. On the suction side, however, both wall-function and low-Reynolds number method failed to predict the variations of heat transfer coefficient and temperature caused by boundary layer flow transition. In the ${\omega}RSM$ results, the wall-function showed reasonable predictions for both the heat transfer coefficient and temperature variations including flow transition onset on suction side, but, low-Reynolds methods did not properly capture the variation of the heat transfer coefficient. The $SST_+{\gamma}-Re_{\theta}$ transition model showed variation of the heat transfer coefficient on the transition regions, but did not capture the proper transition onset location, and was found to be much more sensitive to the inlet turbulence length scale. Overall, the Reynolds stress model and wall function configuration showed the reasonable predictions in presented cases.

버섯 발생이 부진한 표고골목 내부균사의 생리적 특성 및 해균 조사 (Investigation of Harmful Microorganisms and Physiological Characteristics of Mycelia in the Bed-log of Shiitake Strains Showing Low Fruit-body Productivity)

  • 박원철;이봉훈;유성열;가강현
    • 한국균학회지
    • /
    • 제34권2호
    • /
    • pp.88-91
    • /
    • 2006
  • 가평에서 낮은 생산성을 보이는 저온성 품종과 고온성 품종의 균사상태 및 골목 표면에 형성된 해균에 대한 조사를 시도했다. 순수배지에서의 균사생장력을 조사한 결과, 저온성 균주는 분리균에 비해 보존균의 생장력이 1.1% 정도 떨어지는 것으로 나타났으며, 고온성 균주는 분리균의 생장력이 보존균의 생장력에 비해 8.0% 정도 떨어지는 것으로 나타났다. 톱밥배지에서의 균사생장력을 조사한 결과, 고온성 분리균은 보존균에 비해 10.8%정도 생장력이 떨어졌으며, 저온성 분리균은 보존균에 비해 25.1% 떨어지는 것으로 나타났다. 중량감소율 조사결과, 고온성 분리균은 보존균에 비해 20.1% 정도 중량감소율이 낮았으며, 저온성 분리균도 보존균에 비해 19.0%정도 낮은 것으로 나타났다. 무처리에 비해서는 고온성 보존균이 107.0%, 고온성 분리균이 49.5%, 저온성 보존균이 85.4%,저온성 분리균이 50.0% 더 감소된 것으로 나타났다. 대치배양한 결과, 고온성 분리균과 저온성 분리균 모두 각각의 해당 보존균들과 동일한 균주임을 확인할 수 있었다. 또한 골목에서 검은혹버섯(Hypoxylon truncatum), 구름버섯(Coriolus versicolor), 기와층버섯(Inonotus xeranticus), 삼색도장버섯(Daedaleopsis tricolor), 이중껍질버섯(Graphostroma platystoma), 점균류(Myxomycetes) 2종, 푸른 곰팡이(Trichoderma sp.), Hypoxylon fragiforme, Hypoxylon howeianum, Nitschkia confertula 등 총 11종의 해균이 발견되었으며, 골목들의 상태는 좋지 않았다.

수도의 장해형 냉해에 관한 연구 (Studies on the Effect of Low Temperature Treatment at Meiotic, Heading and Seedling Stage in Paddy Rice)

  • 이홍석;조형열;임병기;허 훈
    • 한국작물학회지
    • /
    • 제15권
    • /
    • pp.85-97
    • /
    • 1974
  • 수도의 불임을 유발하는 조건을 분명히 하고 불임의 원인을 추구하고저 4품종, 3수준의 처리 온도, 3수준의 처리 기간을 조합한 시험과 내냉성 정도의 품종간 차이를 분명히 하고 생육 각기에 있어서의 품종의 내냉성 정도의 상호 관계를 알고저 우리나라의 중요 19품종을 공시 품종으로 저온 처리를 실시한 시험 결과를 요약하면 다음과 같다. 1. 감수분열기의 저온 처리의 영향은 품종에 따라 다르고 수원 213-1에서는 17.5$^{\circ}C$ㆍ3일간의 처리로도 상당한 불임 현상이 나타났지만 Hayayuki, 농백, 진흥에서는 15$^{\circ}C$ㆍ3일간 또는 17.5$^{\circ}C$.5일간 처리로서 약간의 불임율을 나타내었다. 저온 처리에 의한 임실율의 저하는 품종에 따라 출수지연일수, 이삭의 추출도(수원 213-1, 농백, 진흥) 간장(농백, 수원 213-1), 엽이간장(수원 213-1) 등과 유의적 상관 관계를 보였다. 따라서 수원 213-1 및 농백에서는 이삭의 추출도와 임실율과의 회귀직선식으로부터 불임율을 어느 정도 추정할 수 가 있었다. 냉해 정도가 심한 것은 대체로 약 중의 화분 밀도가 낮고 화분의 크기가 작거나, 약 및 화분의 크기가 불균일하고 불임화분이 많았고 수원 213-1에서는 출수 5일후에 개약하지 않은 것이 없었으나 농백, 진흥, Hayayuki에서는 미개약된 것이 많은 경향이었다. 2. 출수기 처리의 경우에도 대체로 감수분열기 처리에 비하여 불임율이 별로 높지 않았으며 양시기 처리 시의 임실율 간에는 유의적 상관이 인정되었으나 농백과 진흥에 있어서는 15$^{\circ}C$.5일간의 처리로도 임실율에 별로 영향하지 않았다. Hayayuki 및 수원 213-1에서는 처리에 의한 미개약 현상이 있었으나 농백 및 진흥에서는 미개약 현상도 많이 볼 수 있었다. 3. 감수분열기의 저온 처리에 의하여 임실율의 저하로 나타난 내냉성 정도에는 품종간에 현저한 차이가 있고 재건, 진흥 등은 임실율이 별로 떨어지지 않았으나 밀성, 수원 8002, Satominoli, 수원 231-1 등은 임실율이 심히 떨어 졌고 출수 지연도 컸다. 임실율이 떨어지는 품종들은 일반적으로 약내 화분 밀도가 낮거나 약의 형태가 비정상인 것이 많거나, 화분의 크기가 적거나, 불임 화분이 많은 경향이었다. 4. 출수기 처리 시에도 불일율의 품종 간 차이는 현저하여 농백, 진흥, 재건, 팔달, Akibare, 밀성, 팔굉 등은 거의 처리의 영향이 없었고 농림나 001, 수성, Hayayuki, 수원 213-1, 수원 210 등은 임실율이 상당히 낮았다. 일반적으로 감수분열기 처리에 비하면 임실율은 약간 높은 편이지만 Hayayuki, 수성, 농림나 001 등은 출수기 처리에서 오히려 임실율이 낮았다. 또 처리 종료 후에는 품종에 따라 미개약 영화가 많은 품종과 개화 수분이 모두 이루어지지만 불임이 되는 품종도 볼 수 있었다. 5. 냉해의 유묘 검정 결과에서 관찰조사와 처리에 의한 생육 억제 정도와는 반드시 일치하지 않았으나 종합적으로 볼 때 제 002, 팔금, 수성 등은 냉해에 강하고 수원 213-1, 재건, 팔달, Shirogane, 팔굉, 만경 등은 약하였다. 6. 감수분열기 및 출수기 처리 시의 일심율과 유묘 시의 냉해 정도 및 생육 억제 정도 등의 상호 관계를 살펴본 즉 대체로 유의적 상관을 보이지 않았다.

  • PDF

지중가온이 온실의 난방부하에 미치는 영향 (The Effect of Soil Warming on the Greenhouse Heating Load)

  • 남상운
    • 한국농공학회논문집
    • /
    • 제48권5호
    • /
    • pp.51-60
    • /
    • 2006
  • In order to examine the heat transfer characteristic of a soil warming system and effects of soil warming on the greenhouse heating load, control experiments were performed in two greenhouses covered with double polyethylene film. One treated the soil warming with an electric heat wire and the other treated a control. Inside and outside air temperature, soil temperature and heat flux, and heating energy consumption were measured under the set point of heating temperature of $5,\;10,\;15,\;and\;20^{\circ}C$, respectively. Soil temperatures in a soil warming treatment were observed $4.1\;to\;4.9^{\circ}C$ higher than a control. Heating energy consumptions decreased by 14.6 to 30.8% in a soil warming treatment. As the set point of heating temperature became lower, the rate of decrease in the heating energy consumptions increased. The percentage of soil heat flux in total heating load was -49.4 to 24.4% and as the set point of heating temperature became higher, the percentage increased. When the set point of heating temperature was low in a soil warming treatment, the soil heat flux load was minus value and it had an effect on reducing the heating load. Soil heat flux loads showed in proportion to the air temperature difference between the inside and outside of greenhouse but they showed big difference according to the soil warming treatment. So new model for estimation of the soil heat flux load should be introduced. Convective heat transfer coefficients were in proportion to the 1/3 power of temperature difference between the soil surface and the inside air. They were $3.41\;to\;12.42\;W/m^{2}^{\circ}C$ in their temperature difference of $0\;to\;10^{\circ}C$. Radiative heat loss from soil surface in greenhouse was about 66 to 130% of total heating load. To cut the radiation loss by the use of thermal curtains must be able to contribute for the energy saving in greenhouse.