• Title/Summary/Keyword: Temperature stability time

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Bread Properties Utilizing Extracts of Mume (매실(Prumus mume Sieb. et. Zucc)추출물을 이용한 제빵 적성)

  • 이연화;신두호
    • The Korean Journal of Food And Nutrition
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    • v.14 no.4
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    • pp.305-310
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    • 2001
  • In order to study bread properties utilizing extracts of fume, mume bread was baked, adding 0, 0.5, 1.0. 1.5 and 2.0 brix of mume extract to wheat flour. The rheological properties, dough pH, dough volume, bread volume, bread color. bread texture and sensory evaluation were tested to examine bread properties baked adding extracts of mume. The results are as follows: The maximum viscosity measured by amylograph decreased gradually with increasing fume extract concentration, while the gelatinization temperature was going up. The development time measured by farinograph increased with use of mime extract, but stability time decreased. After the first fermentation, dough volume decreased greatly under pH 4.0, and there was same tendency in loaf volume. Lightness and redness of the crumb decreased but yellowness increased. Hardness and fracturability of mume bread were lower than control. In sensory evaluation, fume bread with 0.5 brix muse extract was evaluated as the best in taste, texture, flavor and overall acceptability.

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Cost effective and low energy consuming hydrothermal synthesis of Ni based MOF

  • Israr, Farrukh;Kim, Duk Kyung;Kim, Yeongmin;Oh, Seung Jin;Ng, Kim Choon;Chun, Wongee
    • Journal of Energy Engineering
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    • v.24 no.2
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    • pp.51-54
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    • 2015
  • The mesoporous metal organic framework structure of Ni-BTC was successfully synthesized in a low temperature and short operation time via hydrothermal synthesis process. Such operational route virtuously consumed less electrical and thermal energy. It proved time saving along with acceptable product yield (38%). The product was characterized through FESEM, FT-IR, XRD and $N_2$ gas adsorption measurement. Hightemperature stability of synthesized MOF was gauged by diffraction indexing of XRD patterns of as synthesized and heat treated samples of MOFs. The mathematically calculated particle size of Ni-BTC was found to be 42nm.

Studies on the Natural Dyes(12) -Dyeing Properties of Amur Cork Tree Colors for Silk- (천연염료에 관한 연구(12) -황벽 색소의 견섬유에 대한 염색성-)

  • 조경래;강미정
    • Textile Coloration and Finishing
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    • v.12 no.4
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    • pp.239-247
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    • 2000
  • The coloring matter was extracted from the heartwood of Amur cork tree by distilled water. Change of UV-Visible spectra of coloring matter solution by extraction condition and stability for irradiation were determined, and the effect of repeated dyeing with condition of dyebath and mordanting method on shade depth and lightfastness were also investigated. The results are as follows : 1) Absorbance of Amur cork tree extract increased with the lapse of extraction time. λmax of color solution extracted from Amur cork tree was found at 420, 333, and 262nm. 2) Absorbance of Amur cork tree extract decreased remarkably after 2hr irradiation. 3) The K/S of silk fabrics increased with the increase of dyeing temperature, time, amounts of Amur cork tree for extraction, and pH of color solution. 4) K/S of silk fabrics dyed by repeated dyeing method was affected by pH and concentration of color solution. 5) Lightfastness of silk twice dyed with Amur cork tree extract after pre-mordanted by 8%(o.w.f) chromium acetate was moderately improved.

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Study of Pixel Isolated PSCOF Mode

  • Kim, Dong-Woo;Shin, Sung-Tae;Jung, Jong-Wook;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.399-402
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    • 2005
  • We have studied the Pixel Isolated Phase Separated Composite Organic Film (PI-PSCOF). The PI-PSCOF can be made by the anisotropic phase separation between Ferroelectric Liquid Crystals and Pre-polymer materials by irradiating the UV with optimizing its intensity and time. In the technology, the FLC molecules are isolated in pixels where FLCs are surrounded by the inter-pixel vertical polymer walls and the horizontal polymer films on the upper substrate. The good merits of this technology are fast response time, and good mechanical and thermal stability against external high pressure and temperature. We will compare the results obtained from FLC, PSCOF, and PI-PSCOF modes by using the electro-optic measurement and x-ray scattering, and mechanical method. We believe that the PI-PSCOF technology can be a best candidate for future Flexible Display Applications.

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Development of Combustor for Combustible Hazardous Gas (가연성 유해가스 처리를 위한 연소기 개발)

  • 전영남;채종성;김미환
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.4
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    • pp.479-485
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    • 1996
  • Volatile organic compounds are air pollutants exhausting from industrial process, evaporation of solvent, and so on. Most of VOCs are the combustible gas of low calorific value as it is diluted by air. The systems burning such a hazardous gas need to increase enthalpy in order to increase flame stability. In this study an incinerator with reciprocating flow in the honeycomb ceramic has been used for the experiment of VOCs control. By the reciprocating flow system, the enthalpy of combustion gas is effectively regenerated into the enthalpy increases of the combustible gas through the honeycomb ceramic, which provides a heat storage. The position of the reaction zone is strongly dependent on the parameters of mixture velocity and time frequency. Flame front is changed to the point where burning velocity is coincided with burning velocity in the honeycomb ceramic. In this system it is important that flame front should be located symmetrically at the center of honeycomb ceramic for the purpose of increasing the reaction rate at one point. Peak temperature becomes higher with decreasing time frequency, at which the flow direction is regularly reversed.

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The Optiomun Treatment Conditions an the Estimation of Life in the Interface between Epoxy/EPDM (Epoxy/EPDM계면의 최적처리 조건과 수명 예측)

  • Oh, Jae-Han;Bae, Duck-Kweon;Choi, Woon-Shik;Lee, Kyong-Sob
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1978-1980
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    • 2000
  • Because the interfaces between two different materials are the weak-link in the underground power transmission systems, they affects the stability of insulation systems. In this paper, Epoxy/EPDM interface is selected and investigated the optimum condition by variation of interfacial conditions such as roughness of surface, spreading of oils, interfacial pressure and temperature. The breakdown times under the constant voltage below the breakdown voltage were also gamed. The breakdown voltage at the after laying time equivalent to is calculated by the V-t characteristic and the inverse power law. When this is done. the characteristic life exponent n is used and the long time breakdown voltage can be evaluated.

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Application of Discrete-Ordinate Method to the Time Dependent Radiative Heat Transfer Calculations (방향차분법을 적용한 시간종속 복사 열전달 계산)

  • Noh, Tae-Wan
    • Journal of Energy Engineering
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    • v.15 no.4 s.48
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    • pp.250-255
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    • 2006
  • In this study, the discrete ordinates method which has been widely used in the solution of neutron transport equation is applied to the solution of the time dependent radiative transfer equation. The self-adjoint form of the second order radiation intensity equation is used to enhance the stability of the solution, and a new multi-step linearization method is developed to avoid the nonlinearity in the material temperature equation. This new solution method is applied to the well known Marshak wave problem, and the numerical result is compared with that of the conventional Monte-Carlo method.

Evaluation of the Charcoal Tube Sampling Method for Carbon Disulfide in Air (활성탄관법을 이용한 공기중 이황화탄소 농도 측정법에 관한 연구)

  • Lee, Na Roo;Paik, Nam Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.3 no.1
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    • pp.22-36
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    • 1993
  • This study was conducted to evaluate the charcoal tube sampling method for carbon disulfide in the air. Breakthrough was investigated according to flow rate, sampling time and air volume. Also the storage stability by storage method and time was investigated. The results are summarized as follows. 1. The samples stored at room temperature($28.2^{\circ}C$), refrigerator($3.8^{\circ}C$) and freezer($-15.6^{\circ}C$) were analyzed every week to five weeks. At one week storage at room temperature, 3.5% of $CS_2$ in the front section of the charcoal tube migrated into the back section and 57.7% at five weeks. The amount of $CS_2$ in the back section of the charcoal increased continuously by storage time. Migration of $CS_2$ was slow at refrigerator, and stopped occur at freezer. Recovery rate $CS_2$ was 52-82% at room temperature and 92-101% at refrigerator, based on the amount at freezer as a reference value. Thus loss was observed at room temperature. 2. When 6-48 L of fresh air were passed through tubes with spiked amounts of 0.379 and 0.759mg sample, the amounts of $CS_2$ in the back section of charcoal were 5.7-132.4 and 0-92% of the amount in the front section, respectively. The total recovery rates of$CS_2$ from 0.379 and 0.759mg spiked sample were 35.7-101.0% and 9l.3-100.1%, respectively. $CS_2$ loss was observed in 0.379mg spiked sample, but not in 0.759mg spiked sample. In the spiked samples, the amount of $CS_2$ in the back section of charcoal was not affected by flow rate when the air volume was controlled. The amount of $CS_2$ in the back section of charcoal increased over sampling time. And the faster the flow rate, the more the migration amount when the sampling time was the same. 3. A known concentration, 10 ppm of $CS_2$, was produced in a 200 L Tedlar bag. When the air volume was 24, 36, 48 L, breakthrough was 5.8, 16.9, 47.4%, respectively. The sampling flow rate of 0.05, 0.1, 0.2 Lpm did not change the breakthrough rate. Breakthrough increased over sampling time. And the faster the flow rate, the more the breakthrough, when the sampling time was the same.

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Cancellation of Phase Noise in 1.4 GHz RF Signal Transferred to a Remote Site through 13 km Fiber (13 km 광섬유를 통하여 원격지로 전송된 1.4 GHz RF 신호의 위상잡음 제거)

  • Lee, Won-Kyu;Park, Chang-Yong;Mun, Jong-Chul;Yu, Dai-Hyuk
    • Korean Journal of Optics and Photonics
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    • v.21 no.3
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    • pp.103-110
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    • 2010
  • A fiber-phase-noise compensating system was constructed for a 1.4 GHz reference frequency transferred through a 13-km-long fiber spool. The transfer instability was dependent on the temperature variation of the compensating system. With the room temperature variation stabilized within $0.3^{\circ}C$, the transfer instability was $4.6{\times}10^{-14}$ at 0.8 s of average time and $2.5{\times}10^{-16}$ at 1000 s of average time with the fiber phase noise compensated. However, with the room temperature changed by $3.5^{\circ}C$, the transfer instability was $6.8{\times}10^{-14}$ at 1.2 s of average time and $3.0{\times}10^{-15}$ at 1000 s of average time. From this result, the temperature stability condition for the experimental setup could be determined to obtain a transfer instability of $10^{-16}$ at 1000 s of average time.

High-Temperature Corrosion Behavior of Alloy 617 in Helium Environment of Very High Temperature Gas Reactor (초고온가스로 헬륨 분위기에서 Alloy 617의 고온 부식 거동)

  • Lee, Gyeong-Geun;Jung, Sujin;Kim, Daejong;Jeong, Yong-Whan;Kim, Dong-Jin
    • Korean Journal of Metals and Materials
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    • v.50 no.9
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    • pp.659-667
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    • 2012
  • Alloy 617 is a Ni-base superalloy and a candidate material for the intermediate heat exchanger (IHX) of a very high temperature gas reactor (VHTR) which is one of the next generation nuclear reactors under development. The high operating temperature of VHTR enables various applications such as mass production of hydrogen with high energy efficiency. Alloy 617 has good creep resistance and phase stability at high temperatures in an air environment. However, it was reported that the mechanical properties decreased at a high temperature in an impure helium environment. In this study, high-temperature corrosion tests were carried out at $850^{\circ}C-950^{\circ}C$ in a helium environment containing the impurity gases $H_2$, CO, and $CH_4$, in order to examine the corrosion behavior of Alloy 617. Until 250 h, Alloy 617 specimens showed a parabolic oxidation behavior at all temperatures. The activation energy for oxidation in helium environment was 154 kJ/mol. The SEM and EDS results elucidated a Cr-rich surface oxide layer, Al-rich internal oxides and depletion of grain boundary carbides. The thickness and depths of degraded layers also showed a parabolic relationship with time. A normal grain growth was observed in the Cr-rich surface oxide layer. When corrosion tests were conducted in a pure helium environment, the oxidation was suppressed drastically. It was elucidated that minor impurity gases in the helium would have detrimental effects on the high-temperature corrosion behavior of Alloy 617 for the VHTR application.