• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.197-205
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• 2011

Cellulose nanofibrils (CNF) with 50~100 nm diameter were manufactured from micro-size cellulose by an application of a high-pressure homogenizer at 1,400 bar. High strength nanopapers were prepared over a filter paper by a vacuum filtration from CNF suspension. After reinforcing and dispersing CNF suspension, hydroxypropyl cellulose (HPC) and polyvinyl alcohol (PVA)-based composites were tailored by solvent- and film-casting methods, respectively. After 2, 4, 6 and 8 passes through high-pressure homogenizer, the tensile strength of the nanopapers were extremely high and increased linearly depending upon the pass number. Chemical modification of 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) on the nanopapers significantly increased the mechanical strength and water repellency. The reinforcement of 1, 3, and 5 wt% CNF to HPC and PVA resins also improved the mechanical properties of the both composites.

• Laser Solutions
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• v.18 no.2
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• pp.11-13
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• 2015

Pressure-drop in a micro-channel is critical when a hole diameter is less then 100um with the high aspect ratio, more than 40. To minimize these pressure loss for micro-channel applications is important and there would be the best hole diameter, taper angle, and their combinations. In this work, the parametric study for laser drilling of anodized material is conducted to obtain the micro-channel hole with high aspect ratio.

• Explosives and Blasting
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• v.12 no.3
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• pp.32-41
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• 1994

The specific characters in recent Chemical processing and industrial plants are the handling of severe limit conditions such as high pressure, high and low temperature, high speed production and transportation plant automation and appearance of many new hazardous materials in numbers and quantity. The possibilities of these characters causing the accident and environmental pollution in industrial activities become very high. This paper describes the concrete policy In prevent the explosion accident out of the many accidents which are the safety of the safety engineering.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.664-671
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• 2013

The objective of this study was to investigate the effect of high pressure treatment and type of binding agents on the quality characteristics of restructured pork. For binding agents, 2% (w/w) isolated soy protein (SP), 0.5% (w/w) wheat flour (WF) and 0.5% (w/w) ${\kappa}$-carrageenan (KC) were incorporated into meat batter with or without 0.5% (w/w) glucono-${\delta}$-lactone (GdL). The restructured pork was pressurized at varying pressure levels (0.1-450 MPa) for 3 min under ambient temperature and thermal treated at $75^{\circ}C$ for 30 min. As quality parameters of restructured pork, pH, water binding properties, instrumental color and texture profile analysis were determined and compared with control (C, no binder). For type of binders, SP exhibited the best water binding properties, however, the impact on textural properties were lesser than KC and WF. The addition of GdL decreased the pH of restructured pork down to 0.4 unit, while high pressure processing prevented the moisture loss caused from pH decrease by GdL. In particular, meat restructuring efficiency of SP as a binder improved under the presence of GdL. Therefore, the present study demonstrated the potential advantages of low amount of GdL (0.5%, w/w) combined with protein based binder (SP) and high pressure processing in restructuring meat particles.

• Journal of Dairy Science and Biotechnology
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• v.38 no.4
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• pp.230-236
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• 2020

Heat treatment is a fundamental processing technology in the dairy industry. The main purpose of heat treatment is to destroy pathogenic and spoilage promoting microorganisms to ensure milk safety and shelf life. Despite the development of alternative technologies, such as high-pressure processing and pulse field technology for microbial destruction, heat treatment is widely used in the dairy industry and in other food processes to destroy microorganisms. Heat treatment has contributed greatly to the success of food preservation since Pasteur's early discovery that heat treatment of wine and beer could prevent their deterioration, and since the introduction of milk pasteurization in the 1890s. In Korea, food labeling standards do not stratify heat treatments into low temperature, high temperature, and ultra-high temperature methods. Most milk is produced in Korea by pasteurization, with extended shelf life (ESL : 125--140℃ / 1-10 s). Classification based on temperature (i.e. low, high, and ultra-high), is meaningless.

• Transactions of Materials Processing
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• v.6 no.6
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• pp.500-507
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• 1997

The conventional closed-die forgings had been applied to the forging of spur gears. But the forgings require high forging-pressure. In this paper, new precision forging technology have been developed. The developed technology is two steps forging process. Good shaped products are forged successfully with lower forging-pressure than those of conventional forging. The accuracy of the forged spur gear obtained by new precision forging technology is set nearly equal to that of cut spur gear of fourth and fifth class in Korean industrial standard.

• Transactions of Materials Processing
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• v.9 no.4
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• pp.356-361
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• 2000

In this study, when a square cup is under drawing, blank holder pressure necessary for flange wrinkling prevention was experimentally studied. The materials used in the experiment were SPCC steel and SUS304 and the drawing ratio was 1.62∼2.0. Two cases for lubricantion condition were investigated. One was without lubricant and the other was with lubricant of high viscosity.

• 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).

• Journal of Surface Science and Engineering
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• v.46 no.4
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• pp.139-144
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• 2013

c-BN(cubic boron nitride) is known to have extremely high hardness next to diamond, as well as very high thermal and chemical stability. The c-BN in the form of film is useful for wear resistant coatings where the application of diamond film is restricted. However, there is less practical application because of difficult control of processing variables for synthesis of c-BN film as well as unclear mechanism on formation of c-BN. Therefore, in the present study, the structural characterization of c-BN thin film were investigated using $B_4C$ target in r.f. magnetron sputtering system as a function of processing variables. c-BN films were coated on Si(100) substrate using $B_4C$ (99.5% purity). The mixture of nitrogen and argon was used for carrier gas. The deposition processing conditions were changed with substrate bias voltage, substrate temperature and base pressure. Fourier transform infrared microscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used to analyze crystal structures and chemical binding energy of the films. In the case of the BN film deposited at room temperature, c-BN was formed in the substrate bias voltage range of -400 V~ -600 V. Less c-BN fraction was observed as deposition temperature increased and more c-BN fraction was observed as base pressure increased.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.220-226
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• 2014

In the present report, the effects of blanching, steaming, and high temperature/high pressure processing (HTHP) on the amino acid contents of commonly consumed Korean root vegetables, leaf vegetables, and pulses were evaluated using an Automatic Amino Acid Analyzer. The total amino acid content of the samples tested was between 3.38 g/100 g dry weight (DW) and 21.32 g/100 g DW in raw vegetables and between 29.36 g/100 g DW and 30.55 g/100 g DW in raw pulses. With HTHP, we observed significant decreases in the lysine and arginine contents of vegetables and the lysine, arginine, and cysteine contents of pulses. Moreover, the amino acid contents of blanched vegetables and steamed pulses were more similar than the amino acid contents of the HTHP vegetables and HTHP pulses. Interestingly, lysine, arginine, and cysteine were more sensitive to HTHP than the other amino acids. Partial Least Squares-Discriminate Analyses were also performed to discriminate the clusters and patterns of amino acids.