• Bulletin of Food Technology
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• v.15 no.1
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• pp.52-54
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• 2002

식품에 대한 고압의 영향은 이미 19C말이나 20C초부터 연구되어 왔다. 본 논문에서는 식품의 보존기간(shelf-life)에 미치는 고압의 영향과 고압(HHP, High Hydrostatic Pressure)하에서 단백질의 3차 구조가 어떻게 변화하는 지에 대해 살펴 보고자 한다. 보통 식품가공에 적용되는 고압은 몇 초 내지 몇 분 동안에 50∼1000MPa 정도의 압력이 가해지는 것을 말한다. 소비자들이 식품을 선택할 때 가장 먼저 민감하게 느끼는 점은 식품의 색이다. 그러나 색은 가공과정이나 유통기간중에 변색이 쉽다. 따라서 색이나 풍미성분의 손실을 최소화하면서 식품의 보존기간을 늘리기 위해서 고압처리 기술이 주목을 받게 된 것이다. 식품의 색은 소비자들로 하여금 그 식품의 품질을 미리 짐작하게 하는 중요한 요소로서, 과일의 경우는 당도까지도 예측하게 한다. 그러므로 식품의 색이 소비자에게 주는 정보를 과소 평가해서는 안된다.

• Food Science and Industry
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• v.40 no.3
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• pp.23-30
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• 2007

• Food Science and Industry
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• v.40 no.3
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• pp.31-35
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• 2007

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3728-3740
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• 1996

High-quality cups of deep drawing ratio of more than four cannot be simply drawn by conventional drawing and redrawing processes. In the present study, after the first deep drawing process, subsequent hydromechanical reverse redrawing with controlled radial pressure is employed. In order to increase the deep drawing ratio up to muchmore than four, the radial pressure should be controlled independently of the chamber pressure and thus an optimum forming condition can be found easily by varying the radial pressure. The process has been subjected to finite element analysis by using the rigid-platic material modeling considering all the frictional conditions induced by the hydrostatic pressure. In order to consider the pressure effect on the sheet, the pressure distributions on the flange part and the side wall part are calculated mumerically from simplified Navier-stokes equation. The comparison of the computation with the experiment has shown that the finite element modeling can be conveniently emplyed for the design of the process with reliability from the viewpoint of formability.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.373-379
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• 2000

Low salt fermented anchovy was stored at $25^{\circ}C$ for a period of 20 days from the time of ultra-high pressure treatment under different operating conditions, such as magnitude of pressure($(200{\sim}500\;MPa)$, temperature$(20{\sim}50^{\circ}C)$ and treatment time$(5{\sim}20\;min)$ with viable cell count(VCC) and quality assessments conducted at regular intervals. VCC decreased logarithmically during storage. Lower values of VCC in the treated samples were observed compared to the untreated. A gradual increase in peroxide value was noticed during storage, compared to those of the untreated which showed a sudden rise. Thiobarbituric acid value decreased initially and remained at that level before rising almost exponentially between 12 and 20 days. Volatile basic nitrogen increased gradually during storage. Amino nitrogen remained almost constant up to 20 days, regardless of any conditions investigated. High pressure treatment maintained better quality during storage at $25^{\circ}C$ by reducing the viable cell count in low salt fermented anchovy.

• Tribology and Lubricants
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• v.12 no.3
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• pp.85-91
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• 1996

An analysis for turbulent hybrid beatings with fluid inertia and swirl injection effect was derived for studying static characteristics of swirl-controlled hybrid journal. The swirl-controlled hybrid journal beating is considered to have more freedom in stability control in high speed rotating machinery. Current analysis is compared with experimental results with 3-recess hydrostatic journal bearing. The analysis revealed that the fluid momentum exchange at orifice discharge could produce pressure rise inside the recess region which can control the shear flow induced by journal rotation. The analysis also shows that the swirl-controlled hybrid journal beating has a capability of controlling load carrying capacity and stability by manipulating supply pressure and injection angle.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.137-143
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• 2011

Fuel Test Loop(FTL) is a facility which could conduct a fuel irradiation test at HANARO(High-flux Advanced Neutron Application Reactor). FTL simulates commercial NPP's operating conditions such as the pressure, temperature and neutron flux levels to conduct the irradiation and thermo-hydraulic tests. The In-Pile Test Section(IPS) installed in HANARO FTL is designed as a pressure vessel design conditions of $350^{\circ}C$, 17.5MPa. The instrumentation MI-cables for thermocouples, SPND and LVDT are passed through the sealing plug, which is in the pressure boundary region and is a part of instrumentation feedthrough of MI-cable. In this study, the brazing method and performance test results are introduced to the sealing plug with BNi-2 filler metal, which is selected with consideration of the compatibility for the coolant. The performance was verified through the insulation resistance test, hydrostatic test, and helium leak test.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.1055-1065
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• 2020

This study investigated the effects of brine injection and high hydrostatic pressure (HHP) on the quality characteristics of pork loin. Brine with ionic strength conditions (0.7% vs 1.5% NaCl, w/v) were injected into pork loins, and the meat was pressurized up to 500 MPa for 3 min. As a quality indicator, moisture content, color, cooking loss and texture profile analysis (TPA) of pork loins were estimated. Based on the results, brine with low ionic strength (0.7% NaCl) resulted in low injection efficiency and high cooking loss, although, it improved tenderness of pork loin at moderate pressure level (~200 MPa). While high ionic strength condition (1.5% NaCl injection) lowered the hardness of pork loins at relatively high HHP level (400-500 MPa), it also caused high cooking loss. To commercialize the brine injected pork loins, it was necessary to regulate brine compositions, which was not evaluated in this study. Nevertheless, the present study demonstrated that brine injection followed by moderate pressure (200 MPa) could improve the tenderness of pork loins without causing other major quality losses.

• Korean journal of food and cookery science
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• v.30 no.2
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• pp.183-192
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• 2014

This study was conducted to investigate the effect of superheated steam (SHS) on the improvement of quality during the manufacturing process of Samgyetang products. SHS cooking showed the increase in moisture content and the decrease in protein. In terms of chromaticity, the value of L was significantly higher in the $2^{nd}$ SHS cooking compared to conventional cooking. As for texture, the hardness decreased in Samgyetang with SHS cooking than conventional cooking. According to the results of the safety experiment with a 14-day refrigerations storage the total number of bacteria was lower in the SHS cooking compared to conventional cooking. The TBA value increased to 0.59-5.70 mg MD/kg after 15 days; VBN values were also 0.70-4.54 mg% in SHS cooking indicating a slight decomposition. Overall, it was found that SHS cooking and HHP were more preferred and also had an effect of reducing microorganisms, which were improvements in product quality and sanitation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.1
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• pp.44-49
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• 2018

High-strength plastic water supply pipe evaluation method was evaluated in this study. Up to date, high strength water supply pipes that we install are mostly ductile cast iron pipes. Sometimes, a few PVC pipes are installed. Metal pipes have rust problem on the surface, causing serious damage to metal pipes and reducing the expected life span of water piping system. Nowadays, depending on technology development, some companies have improved properties of general PVC pipe performance with remarkable properties that exceed KS and ASTM standard. Here, we suggest a new method of performance evaluation for high-strength water plastic pipes.