• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2006.05a
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• pp.325-328
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• 2006

In low nitrite level, treatment of combined with pressure and thermal processing improved cured meat colour comparing with that of only thermal processing. However, visual colour of only pressurised treatment could not be improved at low nitrite level. Pressure treatment could develop cured meat colour when high nitrite level was added. Moreover, pressurisation combined with thermal processing decreased nitrite residuals compared to thermal processing. Therefore the results indicated that pressurisation combined with thermal processing had potential benefits in appearance of cured meat products, promising improved food safety.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.335-342
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• 2016

The object in this study is to investigate the effects of high pressure and freezing processes on the curdling of skim milk depending on the presence of transglutaminase (TGase) and glucono-δ-lactone (GdL). Skim milk was treated with atmospheric freezing (AF), high pressure (HP), pressure-shift freezing (PSF) and high pressure sub-zero temperature (HPST) processing conditions. After freezing and pressure processing, these processed milk samples were treated with curdling agents, such as TGase and GdL. Pressurized samples (HP, PSF and HPST) had lower lightness than that of the control. In particular, PSF had the lowest lightness (p<0.05). Likewise, the PSF proteins were the most insoluble regardless of whether they were activated by TGase and GdL, indicating the highest rate of protein aggregation (p<0.05). Furthermore, the TGase/GdL reaction resulted in thick bands corresponding to masses larger than 69 kDa, indicating curdling. Casein bands were the weakest in PSF-treated milk, revealing that casein was prone to protein aggregation. PSF also had the highest G' value among all treatments after activation by TGase, implying that PSF formed the hardest curd. However, adding GdL decreased the G' values of the samples except HPST-treated samples. Synthetically, the PSF process was advantageous for curdling of skim milk.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.808-812
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• 2005

The effects of high pressure processing, pressure level (50, 100, 150, and 200 MPa) and pressurized time (0, 5, 10, 15, 30, 45, and 60 min) on the physico-chemical properties of pork M. longissimus dorsi were evaluated. The pH value was affected by both pressure level and pressurized time, especially at 200 MPa (P<0.05). In color measurement, $L^*$ and $a^*$-values were increased by both pressure level and pressurized time, but $b^*$-value did not differ significantly (P>0.05). Water holding capacity (WHC) was significantly decreased (P<0.05) depending on pressure level and pressurized time, while cooking loss was gradually increased. Warner-Bratzler shear force did not differ significantly (P>0.05) among the treatments. These results indicate that high pressure processing below 200 MPa for 1 hr had no effect on the quality of cooked meat, although some alterations were observed before cooking.

• Food Science of Animal Resources
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• v.42 no.3
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• pp.441-454
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• 2022

This study aimed to determine the effect of enzyme, guar gum, and pressure processing on the digestibility and physicochemical properties of age-friendly liver sausages. Liver sausages were manufactured by adding proteolytic enzyme (Bromelain) and guar gum, and pressure-cooking (0.06 MPa), with the following treatments: control, without proteolytic enzyme; T1, proteolytic enzyme; T2, proteolytic enzyme and guar gum; T3, pressure-cooking; T4, proteolytic enzyme and pressure-cooking; T5, proteolytic enzyme, guar gum, and pressure-cooking. The pH was high in the enzyme- and pressure-processed groups. The pressure-processed groups had lower apparent viscosity than other cooking groups, and it decreased during enzyme treatment. Hardness was lower in the enzyme- and pressure-processed groups than in the control, and the T4 was the lowest. Digestibility was the highest in T4 at 82.58%, and there was no significant difference with that in T5. The general cooking group with enzyme and guar gum also showed higher digestibility than the control (77.50%). As a result of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the enzyme- and pressure-treated groups (T4, T5) were degraded more into low-molecular-weight peptides (≤37 kDa) than the control and other treatments. Viscoelasticity showed similar trends for viscous and elastic moduli. Similarly, combined pressure processing and enzymatic treatment decreased viscoelasticity, while guar gum increased elasticity but decreased viscosity. Therefore, the tenderized physical properties and improved digestibility by enzyme and pressurization treatment could be used to produce age-friendly spreadable liver sausages.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.367-377
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• 2001

Plasma is generated by electrical discharge. Most plasma generation has been carried out at low-pressure gas typically less than one millionth of atmospheric pressure. Plasmas are in general generated from impact ionization of neutral gas molecules by accelerated electrons. The energy gain of electrons accelerated in an electrical field is proportional to the mean free path. Electrons gain more energy at low-pressure gas and generate plasma easily by ionization of neutrals, because the mean free path is longer. For this reason conventional plasma generation is carried out at low pressures. However, many practical applications require plasmas at high-pressure. In order to avoid the requirement for vacuum pumps, researchers in Korea start to develop plasmas in high-pressure chambers where the pressure is 1 atmosphere or greater. Material processing, environmental protection/restoration and improved energy production efficiency using plasmas are only possible for inexpensive bulk plasmas. We thus generate plasmas by new methods and plan to set foundations for new plasma technologies for $21^{st}$ / century industries. This technological research will play a central role in material processing, environmental and energy production industries.

• Carbon letters
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• v.3 no.2
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• pp.85-92
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• 2002

4D carbon fiber preforms were manufactured by weaving method and their carbon fiber volume fractions were 50% and 60%. In order to form carbon matrix on the preform, coal tar pitch was used for matrix precursor and high density carbon/carbon composites were obtained by high densification process. In this process, manufacture of high density composites was more effective according to pressure increasement. When densificating the preform of 60% fiber volume fraction with 900 bar, density of the composites reached at 1.90 $g/cm^3$ after three times processing. Degree of pressure in the densification process controls macro pore but it can not affect micro pore. During the carbonization process, micro pore of the preform were filled fully by once or twice densification processing. But micro pore were not filled easily in the repeating process. Therefore, over three times densification processing is the filling micro pore.

• Journal of Information Technology Services
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• v.10 no.1
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• pp.135-149
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• 2011

In this paper, we propose the high-risk group detection model for patients with high blood pressure using case-based reasoning. The proposed model can be applied for public health maintenance organizations to effectively manage knowledge related to high blood pressure and efficiently allocate limited health care resources. Especially, the focus is on the development of the model that can handle constraints such as managing large volume of data, enabling the automatic learning to adapt to external environmental changes and operating the system on a real-time basis. Using real data collected from local public health centers, the optimal high-risk group detection model was derived incorporating optimal parameter sets. The results of the performance test for the model using test data show that the prediction accuracy of the proposed model is two times better than the natural risk of high blood pressure.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.8
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• pp.67-73
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• 2019

An ultra-high pressure treatment device is a device used for increasing the shelf life of food by sterilizing it by applying hydrostatic pressure to solid or liquid food. The ultrahigh pressure treatment system developed in this study is a pressure vessel with a processing capacity of 100 L and a maximum pressure of 700 MPa. Pressure vessels for ultrahigh-pressure processing equipment are manufactured using wire-winding techniques. The design formula for making ultra-high pressure vessels with wire windings is given in ASME Section VIII - Division 3. In this study, the ratio of the cylinder to the winding area that can be applied in a wire-winding application was analyzed using a finite element analysis. Furthermore, the relationship between the variation of the residual stress in the vessel and the ratio of the winding area due to the variation of the winding tension was analyzed, and a design guide applicable to the actual product design was developed. Finally, the design equation was modified by presenting the coefficients to correct the difference between the finite element analysis and the design equation.

• Food Science and Preservation
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• v.6 no.4
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• pp.521-529
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• 1999

The high influx of imported fruits into Korea is threatening to price and quality competition of domestic fruits. This investigation was conducted to raise price and quality competition of domestic fruits and to develop new products. The scale of production and processing, amount of processing and new processing technology were discussed. The area of cultivation land as well as the rate of processing is decreasing annually, an item of processing is limited to several kinds. Accordingly in this study, the status of production and manufacturing of some fruits and the new processing technologies such as high voltage pulsed electric fields, high hydrostatic pressure, ohmic heating, membrane separation and microwave treatment have investigated to fruit processing. Consequently, the minimal processing technology has to take advantage of various agricultural products in the food industry.

• Journal of Powder Materials
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• v.10 no.3
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• pp.181-185
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• 2003

Resistance sintering under ultra-high pressure if developed to fabricate W-Cu composite containing 5 to 80v/o copper. The consolidation was carried out under pressure of 6 to 8 GPa and input power of 18 to 23 kW for 50 seconds. The densification effect and microstructure of these W-Cu composites are investigated. The effect of W particle size on ,sintering density was also studied. The micro hardness was measured to evaluate the sintering effect.