• Title/Summary/Keyword: pressurization

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Effects of High Pressure on pH, Water-binding Capacity and Textural Properties of Pork Muscle Gels Containing Various Levels of Sodium Alginate

  • Chen, Cong-Gui;Borjigin, Gerelt;Jiang, Shao-Tong;Tadayuki, Nishiumi;Atsushi, Suzuki
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.11
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    • pp.1658-1664
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    • 2006
  • The objective of this study was to investigate the effects of sodium alginate (SA) and pressurization levels on pH, water-binding and textural properties of pork muscle gels (PMG) containing salt. Ground lean pork with 1.0% NaCl and a given amount of SA (0.25, 0.5, 0.75 and 1.0%, respectively), was pressurized to 100, 200 or 300 MPa and subsequently gelled by heating. Results showed that addition of SA into pork muscle enhanced water-holding capacity (WHC) of PMG (p<0.05) as SA increased from 0.25% to 1.0%, with pH slightly increased (p>0.05). A decrease (p<0.05) was observed in all textural parameters (hardness, cohesiveness, springiness and chewiness). Pressurization had no effect on the tendency of WHC to increase or the decrease of the textural parameters. However, the effectiveness of pressurization to enhance textural properties of PMG was significant at some SA levels, especially ${\geq}200MPa$ and at ${\leq}0.75%$ SA levels. Different combinations of pressure and SA levels could bring about variation in textural properties of PMG while SA enhanced WHC of pork muscle. The multiformity of the texture will open up a wide range of technological possibilities for the manufacture of pork-based restructured low-fat products.

A Numerical Study on Smoke Control for Smoke Control Systems and Air Flowrate (제연방식과 풍량에 따른 제연성능의 수치적 연구)

  • 박외철
    • Fire Science and Engineering
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    • v.17 no.2
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    • pp.56-61
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    • 2003
  • The smoke removal rate from a room with an opening was investigated for different smoke control systems by using the large eddy simulation turbulence model of the Fire Dynamics Simulator. The decreasing rate of the particles randomly distributed in the 2m X 2m X 2.4m room was com-pared for the ventilation system, pressurization system and extraction system, and for the air flowrate of the ventilation system. Difference in the smoke removal rate among the three smoke control systems was small when the opening was closed. The pressurization system showed less smoke removal rate than the other two systems when the opening existed, and hence is not recommended for subway stations with large openings. It was also shown that a less flowrate in the ventilation system leads to a much longer smoke removal time.

The Influence of Zoning at Shafts of Super-tall Buildings on the Stack Effect and Stairwell Pressurization (초고층건물 샤프트의 수직구획이 연돌효과 및 급기가압 성능에 미치는 영향)

  • Kim, Beom-Kyue;Kim, Hak-Jung;Yeo, Yong-Ju;Leem, Chae-Hyun;Park, Yong-Hwan
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.92-98
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    • 2012
  • This study analyzed the effect of zoning on the distribution of pressure differentials caused by stack effect and air pressurization in a center core type of 80 story super-tall building. The results showed that maximum pressure difference more than 250 Pa can be generated by stack effect without zoning. Zoning of stairwell only resulted in 10 Pa reduction of maximum pressure difference, however, zoning of both stairwell and EV shaft especially at the same floor revealed 50 % reduction in stack effect. It was also analysed that the minimum required air flow rate occurred when the stairwell temperature reached 50 % of temperature difference between indoor and outdoor.

Investigation on Temperature Drop during Pressurant Discharging from Pressurant Tank of Liquid Rocket Propulsion System (II) (액체로켓추진시스템의 가압제 탱크에서 가압제 토출시 온도강하율에 대한 연구(II))

  • Chung, Yong-Gahp;Kim, Yong-Wook;Kim, Yoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.3
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    • pp.279-284
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    • 2008
  • Propellant pressurization system in liquid rocket propulsion system plays a role in supplying pressurant gas at a controlled pressure into the ullage space of propellant tanks. The most important design parameter for such propellant pressurization system is the temperature of pressurant gas fed from pressurant tank, which is placed inside of cryogenic propellant tank. Such pressurant is gaseous state, of which density is very sensitive to the temperature of pressurant. Previous investigation dealt with thermal correlation of pressurant and external fluid at room temperature. This study investigates the temperature variation of cryogenic pressurant (GHe) at the time when the pressurant is coming out of pressurant tank, which is submerged in a liquid oxygen, experimentally as well as numerically.

On the Pressurization for Smoke Control in Building Fires (건물화재에서의 가압방연 설계에 관한 연구)

  • Kim, Myeong-Bae
    • 연구논문집
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    • s.29
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    • pp.39-48
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    • 1999
  • This paper deals with the lobby pressurization for smoke control in building fires. A computer program and related modeling technique are presented. The pressure difference between a lobby and a fire area is not able to be same among building floors because an injection fan can not be installed in each floor. The most remote area from the injection fan has therefore the smallest pressure difference if flow areas are not different through all floors. An adjacent floor from the injection fan has possibly too large pressure difference because the most remote lobby must also meet the required pressure difference over the fire area. Moreover this problem will lead to a larger capacity of the fan. It is showed that the fan capacity can be decreased by adjusting the flow area of air supply duct in each floor.

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Experimental Study on the Structural Integrity of Type IV Hydrogen Pressure Vessels Experienced Impact Loadings (충격 하중 조건에서의 Type IV 수소 압력용기 구조건전성 분석)

  • Han, Min-Gu;Jung, Kyung-Chae;Chang, Seung-Hwan
    • Composites Research
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    • v.29 no.2
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    • pp.60-65
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    • 2016
  • In this paper, finite element analysis and real time monitoring experimental work using FBG sensor were carried out for analyzing structural integrity of a Type IV hydrogen pressure vessel under impact loading condition. By using finite element analysis with the ply based modeling technique, sensor insertion points and pressure condition were suggested. Tensile test with an angle ply specimen was conducted for getting the reliability of FBG sensor insertion method. After fabricating the vessel, total five times pressurization fatigue tests were conducted (Non-impact pressurization: 1, After impact pressurization: 4). Experimental results revealed that filling cycle time was gradually increased and filling gradient was decreased when the vessel experienced impact.

Variation Factor Assessment of Radial Artery Pulse by the Tonometry Angle of the Pulse Pressure Sensor (토노메트리 방식 맥파 측정의 가압 각도에 따른 변동성 평가)

  • Jung, Chang Jin;Jo, Jung Hee;Jun, Min-Ho;Jeon, Young Ju;Kim, Young-Min
    • Journal of Sensor Science and Technology
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    • v.25 no.2
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    • pp.138-142
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    • 2016
  • A pulse measurement by tonometry provides useful information for diagnosis, including not only blood pressure and heart rate but also parameters for estimating a condition of the cardiovascular system. Currently, various pulse measurement devices based on the tonometry have been developed. A reliability of these devices is determined by a positioning technic between the sensor and the blood vessel and a controlling technique of the pressurization level. An angle of the sensor for the pulse measurement seems to be highly related with a measured signal, however, the objective studies for this issue have been not published. In this paper, the variation of the pulse signals by tonometry direction was experimentally assessed according to the angle of the sensor. In order for guaranteeing the repeatability of the experiment, we used a pulse generator device, which can generate human pulse signal by using silicon tube and fluid pump, and developed a structure for precise adjustment of the angle and the pressurization level of the sensor. The angle of the sensor was acquired by an inclinometer, which was attached at the opposite side of the sensor. As results, a coefficient of variation (CV) of a maximum amplitude (MA) of the pulse wave was largely increased over the angle range of $-9{\sim}9^{\circ}$. Furthermore, the changes of the pulse shape showed different aspects according to the sign of the angle tilted along the blood vessel. It is expected that the results of this study can be helpful for developing more precise pulse measurement devices based on the tonometry and applying in clinic.

Comparison of Tensile Strengths in Granite Using Brazilian Tests and Hollow Cylinder Tests for Hydraulic Fracturing Test Interpretation (수압파쇄시험 해석을 위한 중공원통 인장시험과 압열인장시험 화강암 인장강도 비교)

  • Jo, Yeonguk;Chang, Chandong;Lee, Tae Jong;Kim, Kwang-Yeom
    • Tunnel and Underground Space
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    • v.23 no.5
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    • pp.362-371
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    • 2013
  • We conducted hollow cylinder tensile strength tests and Brazilian tests in Seokmo granite to measure tensile strength necessary for estimating the magnitude of the maximum horizontal principal stress in hydraulic fracturing stress measurements. Two different pressurization rates were used in hollow cylinder tests. Tensile strengths were determined to be higher at higher pressurization rate, which suggests that tensile strength should be measurement at the same rate used in actual in situ hydraulic fracturing tests. Considering the effect of pressurization rate and specimen size on tensile strength, the hollow cylinder tests and Brazilian tests yield similar results each other. This demonstrates that Brazilian tests can be utilized to produce representative tensile strengths for interpretation of hydraulic fracturing test results.