• Food Science of Animal Resources
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• v.28 no.4
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• pp.415-421
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• 2008

This study evaluated the effects of thermal processing combined with high pressure on the properties of cooked pork. Pressurization followed by heating (PFH), heating followed by pressurization (HFP) and heating under pressurization (HUP) treatments were compared to a heated only control. Cooked meat without simultaneous pressurization showed little or no decrease in water binding properties relative to the control, regardless of the sequence of pressurization and heating. However, HUP treated pork had significantly higher water binding properties than the control (p<0.05). The pH values of all treatments were not significantly different with the exception of HUP at 300 MPa. The HUP treated pork showed the best tenderizing effects among all the treatments tested and the effect was more significant at increased pressure levels (p<0.05). In addition, increasing pressure levels significantly increased the L-values of pork (p<0.05). PFH and HFP treated pork had significantly lower a-values (p<0.05), while no significant differences were observed in HUP. HUP treated pork had the lowest b-values at 100 MPa. however, the differences were not significant at increasing pressure levels. These results indicate that heating under pressure is the best cooking condition for improving the quality characteristics of pork without adversely affecting its appearance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1136-1140
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• 2011

This study was designed to evaluate the potential of using high pressure processing (HPP) for extending shelf life of seasoned squid during refrigerated storage. The vacuum-packed seasoned squid samples were subjected to 400 MPa for 20 min using a custom-made high pressure processor. Microbial counts, dimethylamine (DMA), trimethylamine (TMA), total biogenic amine, autolytic activity were determined on days 0, 7, 14, and 21 of refrigerated storage. The numbers of indigenous bacteria were effectively reduced by 2.77 log CFU/g after HPP treatment. The amounts of DMA and TMA produced in the control samples increased up to 15.99 and 42.82 mg/g after 7 days of refrigerated storage when compared to 5.27 and 10.21 mg/g the HPP-treated samples, respectively. The autolytic activity of the HPP-treated sample (4.32 nkat/g) significantly lower than that of the control (7.13 nkat/g) after 7 days of refrigerated storage. Therefore, HPP can be applied as a potential squid processing method microbiological safety and shelf life.

• Transactions of Materials Processing
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• v.19 no.7
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• pp.423-428
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• 2010

Carbon nanotubes(CNTs) are expected to be ideal reinforcements of metal matrix composite materials used in aircraft and sports industries due to their high strength and low density. In this study, a high pressure torsion(HPT) process at an elevated temperature(473K) was employed to achieve both powder consolidation and grain refinement of aluminummatrix nanocomposites reinforced by 5vol% CNTs. CNT/Al nanocomposite powders were fabricated using a novel molecular-level mixing process to enhance the interface bonding between the CNTs and metal matrix before the HPT process. The HPT processed disks were composed of mostly equilibrium grain boundaries. The CNT-reinforced ultrafine grained microstructural features resulted in high strength and good ductility.

• Resources Recycling
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• v.24 no.2
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• pp.29-35
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• 2015

A feasibility test was carried out for upcycling of waste jelly-filled communication cables together with the development of environmentally friendly processes and equipments. High pressure water injection is proved to be an exceptionally environmentally friendly and highly efficient mechanical process. A batch-type cable barking equipment is designed and built on the basis of computational fluid dynamics modelling. It is optimized in terms of energy consumption and productivity with very high copper recovery of 99.5%. Copper nano-powder is prepared by an electrical wire explosion in ethanol media in order to improve the value of final products, and the preliminary economical assessment is also conducted.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.88-88
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• 2003

Optical Emission Spectroscopy(OES) is a very important technology for real-time monitoring of plasma in a reactor during dry etching process. OES technology is non-invasive to the plasma process. It can be used to collect information on excitation and recombination between electrons and ions in the plasma. It also helps easily diagnose plasma intensity and monitor end-point during plasma etch processing. We studied high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar plasma with an OES as a function of processing pressure, RIE chuck power, ICP source power and gas composition. The scan range of wavelength used was from 400 nm to 1000 nm. It was found that OES peak Intensity was a strong function of ICP source power and processing pressure, while it was almost independent on RIE chuck power in BCl$_3$-based planar ICP processes. It was also worthwhile to note that increase of processing pressure reduced negatively self-induced dc bias. The case was reverse for RIE chuck power. ICP power and gas composition hardly had influence on do bias. We will report OES results of high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar Plasma in detail in this presentation.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.268-268
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• 2012

Atmospheric pressure microwave induced plasmas are used to excite and ionize chemical species for elemental analysis, for plasma reforming, and for plasma surface treatment. Microwave plasma differs significantly from other plasmas and has several interesting properties. For example, the electron density is higher in microwave plasma than in radio-frequency (RF) or direct current (DC) plasma. Several types of radical species with high density are generated under high electron density, so the reactivity of microwave plasma is expected to be very high [1]. Therefore, useful applications of atmospheric pressure microwave plasmas are expected. The surface characteristics of SUS304 stainless steel are investigated before and after surface modification by microwave plasma under atmospheric pressure conditions. The plasma device was operated by power sources with microwave frequency. We used a device based on a coaxial transmission line resonator (CTLR). The atmospheric pressure plasma jet (APPJ) in the case of microwave frequency (880 MHz) used Ar as plasma gas [2]. Typical microwave Pw was 3-10 W. To determine the optimal processing conditions, the surface treatment experiments were performed using various values of Pw (3-10 W), treatment time (5-120 s), and ratios of mixture gas (hydrogen peroxide). Torch-to-sample distance was fixed at the plasma edge point. Plasma treatment of a stainless steel plate significantly affected the wettability, contact angle (CA), and free energy (mJ/$m^2$) of the SUS304 surface. CA and ${\gamma}$ were analyzed. The optimal surface modification parameters to modify were a power of 10 W, a treatment time of 45 s, and a hydrogen peroxide content of 0.6 wt% [3]. Under these processing conditions, a CA of just $9.8^{\circ}$ was obtained. As CA decreased, wettability increased; i.e. the surface changed from hydrophobic to hydrophilic. From these results, 10 W power and 45 s treatment time are the best values to minimize CA and maximize ${\gamma}$.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.805-816
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• 2014

We investigated the quality characteristics and resulting sensory evaluation of semi-dried silver pomfret treated with high hydrostatic pressure (HHP) processing and brining for 14 days at 4 and $10^{\circ}C$ to evaluate the effects of treatment with HHP processing. HHP treatment and brining could cause compaction of fibers and the space between muscle. The G' values of all samples were higher than the G" values and the tan ${\delta}$ values of the tissue ranged from 0.222 to 0.251 with no further changes observed during storage. HHP treatment and brining significantly increased the total color difference, and the HHP and brine-treated group scored significantly higher than the others in terms of sensory evaluation. HHP treatment combined with brining could have a significant effect on the quality characteristics of the semi-dried products and their storage stability, and it is suggested from the results that they may have the potential to satisfy the requirements to produce commercially marketable food grade products.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.702-707
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• 2013

High-quality ${\beta}$-silicon carbide (SiC) coatings are expected to prevent the oxidation degradation of carbon fibers in carbon fiber/silicon carbide (C/SiC) composites at high temperature. Uniform and dense ${\beta}$-SiC coatings were deposited on carbon fibers by low-pressure chemical vapor deposition (LP-CVD) using silane ($SiH_4$) and acetylene ($C_2H_2$) as source gases which were carried by hydrogen gas. SiC coating layers with nanometer scale microstructures were obtained by optimization of the processing parameters considering deposition mechanisms. The thickness and morphology of ${\beta}$-SiC coatings can be controlled by adjustment of the amount of source gas flow, the mean velocity of the gas flow, and deposition time. XRD and FE-SEM analyses showed that dense and crack-free ${\beta}$-SiC coating layers are crystallized in ${\beta}$-SiC structure with a thickness of around 2 micrometers depending on the processing parameters. The fine and dense microstructures with micrometer level thickness of the SiC coating layers are anticipated to effectively protect carbon fibers against the oxidation at high-temperatures.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.110-114
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• 2001

The welding pressure in porthole die extrusion is affected by the shape of welding chamber. It is very important to increase the welding pressure when the tube is used particulary as the materials of hydroforming processing. The high circumferential stress of the tube would make the welding pressure increase during the porthole die extrusion. In order to increase the circumferential stress, it is necessary to make the billets pass through the narrow gap between the conical die and the conical mandrel. This paper describes the welding pressure by the experiments with the two types of the chamber. One of them is the chamber between the flat die and straight mandrel, and the other one is the chamber between the conical die and conical mandrel. The result of the experiments show that the conical chamber makes the welding pressure increase by the effect of the reducing the diameteres of tube.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.33-34
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• 2003

Lyocell yarns were treated with NaOH, liquid ammonia, high pressure steam and polycarboxylic acids, and dyed with five reactive dyes. The water content of the samples was also measured by the centrifugal and chromatographic techniques. The total pore volume w as substantially increased by NaOH treatment, while decreased by high pressure steaming. The pore size distributions for the dyed samples were affected by the dyes used.