• Title/Summary/Keyword: high temperature high pressure

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Inactivation Kinetics of Listeria innocua ATCC 33090 at Various Temperature Heating-up and Pressure Building-up Rates

  • Ahn, Ju-Hee;Balasubramaniam, V.M.
    • Food Science and Biotechnology
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    • v.16 no.2
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    • pp.255-259
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    • 2007
  • The effects of temperature heating-up rate and pressure building-up phase on the inactivation of Listeria innocua ATCC 33090 were evaluated in buffered peptone water. The number of L. innocua was reduced by 5.57 and 6.52 log CFU/mL during the nonisothermal treatment (the come-up time followed by isothermal process) and the isothermal treatment, respectively, at $60^{\circ}C$. When compared to the isothermal treatment (0.76$33.2^{\circ}C/min$ of temperature heating-rate. The effect of the combined high pressure and thermal processing on the inactivation of L. innocua increased with increasing pressure and temperature. At all temperature levels from 40 to $60^{\circ}C$ under 700 MPa, L. innocua was not detected by enrichment culture (>7 log reduction).

Geochemistry of the Gneisses in the Jangsu Area, Jeonbuk, Korea (전북 장수지역에 분포하는 편마암류의 지구화학적 연구)

  • Son, Jeong-Mo;Shin, In-Hyun;Ahn, Kun-Sang
    • Journal of Integrative Natural Science
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    • v.4 no.1
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    • pp.58-71
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    • 2011
  • The precambrian gneisses are widely distributed in the Jangsu area. This study focuses on the metamorphic mineral assemblages and metamorphic P-T conditions of the gneiss. We have analyzed garnet, biotite and plagioclase among the gneiss through the EPMA analysis, and calculated the metamorphic temperature and pressure accordingly. The metamorphic temperature was estimated by the average of values from the garnet and biotite formulas, and the metamorphic pressure by value of the Hoisch(1990) geopressured on garnet-biotite-plagioclase. The mineral sample we examined shows garnet-biotite-plagioclase-quartz composite and garnet-plagioclase-orthoclase-quartz composite. Garnet shows almandine-pyrope solid solution in general, while porphyroblastic gneiss shows almandine-grossluar solid solution. The fact that the abundances, observed by garnet profile, are almost identical in both the central region and the outer egion indicates that the crystal was developed uniformly. There is almost negligible variance in biotite on metamorphic grade, and andesine is observed in plagioclase. The metamorphic temperature and pressure from EPMA analysis and its indications are as follows: the middle-temperature, high-pressure metamorphism ($500-650^{\circ}C$, 6.9-10 kbar) ensued in the beginning, and then was followed by the high-temperature, middle-pressure($600-740^{\circ}C$, 2.7-5.9 kbar) to ($500-540^{\circ}C$, 3.1 kbar) retrograde metamorphism.

Advances in Non-Interference Sensing for Wearable Sensors: Selectively Detecting Multi-Signals from Pressure, Strain, and Temperature

  • Byung Ku Jung;Yoonji Yang;Soong Ju Oh
    • Journal of Sensor Science and Technology
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    • v.32 no.6
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    • pp.340-351
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    • 2023
  • Wearable sensors designed for strain, pressure, and temperature measurements are essential for monitoring human movements, health status, physiological data, and responses to external stimuli. Notably, recent research has led to the development of high-performance wearable sensors using innovative materials and device structures that exhibit ultra-high sensitivity compared with their commercial counterparts. However, the quest for accurate sensing has identified a critical challenge. Specifically, the mechanical flexibility of the substrates in wearable sensors can introduce interference signals, particularly when subjected to varying external stimuli and environmental conditions, potentially resulting in signal crosstalk and compromised data fidelity. Consequently, the pursuit of non-interference sensing technology is pivotal for enabling independent measurements of concurrent input signals related to strain, pressure, and temperature, ensuring precise signal acquisition. In this comprehensive review, we present an overview of the recent advances in noninterference sensing strategies. We explore various fabrication methods for sensing strain, pressure, and temperature, emphasizing the use of hybrid composite materials with distinct mechanical properties. This review contributes to the understanding of critical developments in wearable sensor technology that are vital for their ongoing application and evolution in numerous fields.

The Analysis of Minerals and Free Amino Acid in Brown Stockwith Extracted Methods Varied (추출방법을 달리한 브라운 스톡의 무기질 및 유리아미노산 분석)

  • Jang, Hyuk-Rae;Lee, Bo-Soon;Choi, Soo-Keun
    • Culinary science and hospitality research
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    • v.14 no.3
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    • pp.210-222
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    • 2008
  • This study showed that the brown stock, which is the base of demi-glace sauce, extracted by using a high pressure heating extractor is more advantageous than that extracted by the traditional extraction method for the mass production. We compared the former with the latter in terms of minerals and free amino acids. The results of this study are summarized as follows. When mineral contents were compared, the brown stock extracted by high.pressure heating extraction showed the tendency of increase in mineral contents in proportion to heating temperature and heating time, but, from extraction temperature of 140$^{\circ}C$, the contents of K, Mg, Na and P decreased with the increase of extraction time. In addition, mineral contents in the brown stock extracted by high-pressure heating extraction were generally lower than those in brown stock extracted by the traditional extraction method. This result was produced probably because materials were added repeatedly in the traditional method. Amino acids contents in brown stock according to the extraction methods were also examined. They increased with the increase in the number of extractions in the brown stock extracted by the traditional method, and those in the brown stock extracted using a high pressure heating extractor increased with the increase in heating temperature and extraction time. The results of this study are expected to be useful as a practical material for the mass production of brown stock products.

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Design and Validation Test of Rocket Engine Head Generating High Temperature and High Pressure Steam (고온고압 증기 발생장치의 설계 및 예비운용시험)

  • Park, Jinsoo;Yu, Isang;Oh, Junghwa;Ko, Youngsung;Kim, Kyungseok;Shin, Dongsun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.637-642
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    • 2017
  • In this study, cold flow and combustion tests are conducted and analyzed to validate designed rocket engine head generating high temperature/pressure steam. At first, uni-injector was designed and manufactured, and cold flow test was conducted. Through this, differential pressure that can supply designed flow rate was confirmed. Also, Each injector's spray pattern were confirmed by patternator. Based on cold flow test results, we selected injectors among the candidates and arranged them on engine head, and cold flow and propellant spray tests were conducted. Finally, combustion test was carried out to analyze the flow rate, pressure, combustion efficiency. As a result, validation of rocket engine head for the development of the high temperature and high pressure steam generator has been completed.

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Study of spatial temperature distribution during combustion process in a high temperature and pressure constant volume chamber (고온 고압 정적 연소실에서 연소과정에 따른 온도 분포 측정)

  • Kim, Ki-hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.345-350
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    • 2017
  • Downsizing is widely applied to diesel engines in order to improve fuel efficiency and reduce exhaust emissions. Engine sizes are becoming smaller but pressure and temperature inside combustion chambers are increasing. Therefore, research for fuel spray under high pressure and temperature conditions is important. A constant volume chamber which simulates high temperature and pressure likely to be found in diesel engines was developed in this study. Pressure and temperature were increased abruptly because of ignition of the pre-mixture in the constant volume chamber. Then pressure and temperature were gradually decreased due to the heat loss through the chamber wall. Fuel spray occurred when temperature and pressure were reached at the target condition. In this experiment, the temperature condition should be exactly defined to understand the relation between fuel evaporation and ambient temperature. A fast response thermocouple was developed and used to measure the temporal and spatial temperature distribution during the combustion process inside the combustion chamber. In the results, the core temperature was slightly higher than the bulk temperature calculated by the gas equation. Ed-note: do you want to say 'ideal gas equation'? This was attributed to the heat transfer loss through the chamber wall. The vertical temperature deviation was higher than the horizontal temperature deviation by 5% which resulted from the buoyancy effect.

Vibration Analysis of Pipe with Elbow subject to Internal Pressure and Temperature (내압 및 온도조건을 고려한 Elbow부가 있는 원형배관의 진동해석)

  • Kim, Woel-Tae;Lee, Hyun-Seung;Lee, Young-Shin;Cho, Taek-Dong;Shin, Sung-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.223-226
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    • 2004
  • Vibration analysis of pipe with Elbow subject to internal pressure and temperature is studied through a commercial finite element analysis tool. The natural frequency of Elbow increased very slightly as internal pressure increases. Meanwhile, the frequency of Elbow decreased as temperature increases. It is shown that frequency deviation caused by temperature was greater than that caused by pressure. As the length of Elbows increases, frequency deviation by temperature stew rapidly, but frequency deviation by pressure was not so high. It is concluded that more concern needs to be focused on temperature rather than on pressure in terms of natural frequency.

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A Study on the Development of Hydrostatic High Speed Spindle for Grinding Machine (고속 연삭기용 유정압 스핀들 개발에 관한 연구)

  • Kim, Jeong-Suk;Cho, Yong-Kwon;Park, Jin-Hyo;Moon, Hong-Man
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.1
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    • pp.96-100
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    • 2011
  • The hydrostatic bearings have a relatively small run-out comparing to its shape error by fluid film effect in hydrostatic state as like pneumatic bearing and have a high stiffness, load capacity and damping characteristics. As there is no maintenance and semipermanent in these bearing type, it has been usually adopted as main spindle bearing for grinding machine. In this thesis, to develop hydrostatic bearing for high speed spindle, the cooler setting temperature, bearing clearance and nozzle pressure of belt-driven hydrostatic bearing are investigated. The bearing temperature is decreased, as the cooler setting temperature is lower, nozzle pressure is higher and bearing clearance is wider. The front temperature of bearing is nearly $8^{\circ}C$ higher than the rear one up to 13,000 rpm of spindle revolution. The thermal deflection of X-axis is ${\pm}16\;{\mu}m$ in range of 12,000 rpm-13,000 rpm. Therefore, it is conformed that the built-in motor hydrostatic bearing can be used to high speed spindle.

Evaluation of Granite Melting Technique for Deep Borehole Sealing (심부시추공 밀봉을 위한 화강암 용융거동 평가)

  • Lee, Minsoo;Lee, Jongyoul;Ji, Sung-Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.4
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    • pp.479-490
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    • 2018
  • The granite melting concept, which was suggested by Gibb's group for the closing of a deep borehole, was experimentally checked for KURT granite. The granite melting experiments were performed in two pressure conditions of atmospheric melting with certain inorganic additives and high pressure melting formed by water vaporization. The results of atmospheric tests showed that KURT granite started to melt at a lower temperature of $1,000^{\circ}C$ with NaOH addition and that needle shaped crystals were formed around partially melted crystals. In high pressure tests, vapor pressure was increased by adding water with maximum pressure of about 400 bars. KURT granite was partially melted at $1,000^{\circ}C$ when vapor pressure was low. However, it was not melted at vapor pressures higher than 200 bars. Therefore, it was determined that high pressure with a small amount of water vapor more effectively decreased the melting point of granite. Meanwhile, high temperature and high pressure vapor caused severe corrosion of the reactor wall.

Numerical Simulation Study on Supersonic Combustion using the Cavity (공동을 이용한 초음속 연소의 수치적 연구)

  • Jeong, Eun-Ju;Jeung, In-Seuck
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.255-260
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    • 2005
  • To achieve efficient combustion within a manageable length, a successful fuel injection scheme must provide rapid mixing between the fuel and airstreams. The aim of the present numerical research is to investigate the flame holding and combustion enhancement. Additional fuel into the cavity prevents shear flow impingement on the trailing edge of the cavity. The high temperature freestream flow mixes with the cold hydrogen fuel that is injected into the cavity and raises the fuel temperature remarkably and become to start combustion. The high pressure in the cavity due to the cavity structure and combustion leads the hydrogen fuel to upstream. The shock in the cavity to be generated by the fuel injection joins together and reflects off the ceiling wall. This makes high pressure and low mach number region and makes a small recirculation in this region. This high stagnation temperature is nearly recovered in the shear layer in front of the cavity and leads to start combustion. In the downstream of the cavity, the wall pressure drops significantly. This means that the combustion phenomenon is diminished. Because fuel lumps at the trailing edge of the cavity then it spreads after the cavity so, in this region there is a strong expansion.

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