• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.504-508
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• 2011

The objective of this study was to determine the extent to which acetaldehyde (AA) and formaldehyde (FA) migrated from polyethylene terephthalate (PET) bottles into mineral water during storage at 25 and 35$^{\circ}C$ for 240 days. Generally, AA and FA were observed to migrate more at 35$^{\circ}C$ than at 25$^{\circ}C$. The amount of FA in the samples irradiated under UV lamps was higher than in those stored in the dark over the storage period and vice versa for AA. Using a triangular test, the sensory panels distinguished a difference between one sample and the other two mineral water samples that had been exposed to UV lamps after 60 days of storage at 35$^{\circ}C$ (p<0.05). At this time, FA and AA concentrations were measured at 267.4 and 515.3 g/L, respectively. After 120 days, an independent mineral water sample from the other two samples in all treatments could be distinguished by the panel members at a significance level of p<0.001.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.472-477
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• 2016

We studied the effects of anodic oxidation treatments of carbon fibers on interfacial adhesion of the carbon fibers-reinforced epoxy matrix composites with various current densities. The surface of treated carbon fibers was characterized by atomic force microscope (AFM), field emission-scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The interlaminar shear strength (ILSS) of the composites was determined by a short beam shear test. This result showed that both the roughness and oxygen group of the carbon fibers surface increased in proportion to the current density. After anodic-oxidation-treated, the ILSS also increased as a function of the current density. In addition, the proportional relationship between ILSS and phenolic hydroxyl group was confirmed. The ILSS of the CF-2.0 sample increased by 4% compared to that of the CF-AS sample, because the anodic oxidation treatment increased the oxygen group and roughness on the carbon fibers surface, which leading to the improvement of the interfacial adhesion of the carbon fibers-reinforced epoxy matrix composites. Among these, the phenolic hydroxyl group which has the proportional relationship with ILSS is found to be the most important factor for improving the interfacial adhesion of the carbon fibers-reinforced epoxy matrix composites.

• Polymer(Korea)
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• v.30 no.2
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• pp.168-174
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• 2006

To utilize as highly functional scaffolds for tissue engineering by improving hydrophobicity and cell compatibility of the exist polymer scaffolds, the biodegradable poly(L-lactic acid) (PLLA) films and scaffolds having the optimal hydrophilicity were prepared by in situ plasma treatment and grafting of a carboxyl acid-containing monomer, acrylic acid (AA) in the chamber. From the results of surface analyses, surface-modified nonporous PLLA film and dual pore scaffold surfaces showed high hydrophilicity due to the decrease in contact angle and the increase in carboxylic groups as compared with untreated PLLA control. In particular, among various surface modification methods, Ar(argon)+AA+AA sample prepared by Ar plasma and then acrylic acid treatments displayed lower contact angle and more carboxylic groups thar Ar/AA and Ar+TP(thermal polymerization) samples, indicating that Ar+AA+AA sample was optimally treated for improving its hydrophilicity. In the cases of surface modified nonporous PLLA films and dual pore scaffolds, the adhesion and proliferation of chondrocytes increased with increasing their hydrophilicity.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.408-413
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• 1992

This study was conducted to determine the effect of the homogenizing grade of sample on absorbance of near infrared reflectance spectrophotometer with which chemical compositions of food were rapidly and effectively analyzed. By the mathematical treatment of absorbance values standard error of prediction was reduced as follows. 1. The absorbance values of various samples ground for the same periods of time were calibrated before or after treatment with first or second derivative in an attempt to accurately predict the components of samples ground for the different periods of time. The standard error of prediction for moisture content were 1.478%, 0.658% and 0.580%, respectively, those for fat content 0.949%, 0.637% and 0.527%, respectively, and those for protein content 0.514%, 0.493% and 0.394%, respectively. Calibration of absorbance values after second derivative treatment showed the highest accuracy in predicting sample components. 2. The absorbance values of various samples ground for the different periods of time were calibrated before or after treatment with first or second derivative in order to accurately predict the components of samples ground for the different periods of time. The standard error of prediction for moisture content were 1.026%, 0.589% and 0.568%, respectively, and those for protein content 0.860%, 0.557% and 0.399%, respectively. The standard error of prediction were lower in the order of calibrations before and after first and second derivative treatments. As a result, calibration of absorbance values after second derivative treatment showed higher accuracy regardless of grinding time of samples.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.184-189
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• 2001

Comparative effects of gamma irradiation and methyl bromide (MeBr) fumigation on water-soluble components of small red bean and mung bean were investigated. The levels of soluble solid and reducing sugar of soaked water at $20^{\circ}C$ for 16 h definitely increased as irradiation dose increased, which was more apparent in small red bean than in mung bean. But, their levels of MeBr-fumigated sample showed a similar result to those of the control, except for soluble solid of small red bean. The pH of soaked water was insignificantly different among treatments. The decrease in lightness (L value) and the increases of redness (a value) and yellowness (b value) were remarkable as irradiation dose increased, which was more significant in fumigated samples. The ${\Delta}E$ values of fumigated sample showed almost equaled to those of 10 kGy in red bean and 30 kGy in mung bean, respectively. Gamma irradiation caused the increase in free amino acids of soaked water, that mainly consisted of asparagine, glutamic acid, and valine, while fumigation reduced their contents. The extractables in soaked water, such as soluble solid and reducing sugar, showed a highly positive correlation with irradiation dose applied.

• Journal of the Korean Society of Food Science and Nutrition
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• v.9 no.1
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• pp.15-22
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• 1980

In this study, two species of algae, Ecklonia stolonifera, Sargassum thunbergii and one species of marine plant, Zostera marina(rhizoid and stem) were collected and extamined to determine the extractability of water soluble protein and the influences of various factors including extraction time, temperature, ratio of sample vs solvent and pH upon the extractability were tested. The effects of precipitation treatments for isolation of algal protein from the extracts(TCA treatment, methanol treatment and pH control) were also tested. Amino nitrogen and total nitrogen of purified samples made by obtained optimum conditions were estimated. The effect of the ratio of sample vs solvent on extractability differed from species to species which was enhances at 1:100(w/v) in Sargassum thunbergii and Zostera marina while 1:150(w/v) for Ecklonia stolonifera. The effect of extraction time and temperature was revealed differently in all species which might be considered to be caused by differences in the constitution of algal tissues. But in case of TCA insoluble nitrogen, it was showed the maximum extractability at $40-50^{\circ}C$ for 1 hour extraction. The optimum pH for the ext action of total nitrogen was 9-12 while the optimum pH was 6-7 for TCA insoluble nitrogen. And the pH control appeared to be most effective in the influence of precipitation treatment for isolation of algal protein.

• Korean Journal of Poultry Science
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• v.17 no.2
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• pp.109-114
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• 1990

Enzymatic activity of isolated Lysozyme from egg white by cation ion-exchange chromatography was detected with various methods and stability of lysozyme in solution was studied by heat and pH treatments. Lysozyme activity refered to mg pure lysozyme/mg sample was more accurate although it needed standard lysozyme. But lysozyme activity refered to units/mg sample could be detected easily and reducted total detection time. Enzymatic activity of isolated lysozyme which dissolved in 0.066M phosphate buffer(pH 6.3) and then incubated at $37^{\circ}C$ for 2hr was increased remarkably on the lysis of Micrococcus lysodeikticus. The activity of isolated lysozyme by CM Sephadex C-25 was higher in eluting solution of above O. D. 1.0 at 640nm and attained 36, 000 units/mg solid. The stability of isolated lysozyme was decreased by various heat treatment. Activity began to decrease above 6$0^{\circ}C$ and dropped rapidly at $100^{\circ}C$. Especially, 35% loss of activity occured in 0.066M phosphate buffer at $100^{\circ}C$. for 15min. The stability of lysozyme was also affected by pH. lysozyme was very stable in acidic solution but in alkaline solution. Enzymatic activity showed maximum value at pH 3.0 solution while decreased rapidly above pH 6.0 solution.

• Journal of muscle and joint health
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• v.2 no.1
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• pp.41-72
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• 1995

The purpose of this study is to examine the effects of assertiveness training and value clarification training on nurse's conflict and conflict management mode. Fifty seven registered nurses participated in the study ; they were employed by three general hospital located in Daegu, Korea. The study employs two treatment groups. The assertiveness training group consisted of subjects who participated in 90-120 minutes sessions of assertiveness training nine times over five weeks. The other treatment group, was adiministed nine, 90-120 minutes sessions of value clarification during the same period. For the control group, nursing subjects were appointed the training after five weeks. Pre-test evaluation were administered to all subjects in three groups prior to one week of the treatment. Role conflict Inventory-general(RCI-G) and Communication Conflict Inventory-general (CCI-G) measure nurse's conflict management mode. Post-test evaluation were administered to all subjects in three groups two weeks after the last session by Role Conflict Inventory-Specific(RCI-S), Communication Conflict Inventory-Specific (CCI-S), Management Model-Specific(CMMI-S). The analysis of variance(ANOVA) and covariance(ANCOVA) on gain scores were running the SPSS program. In order to test statistical differences among mean scores of the scales obtained after treatment, multiple comparisons were carried out by Turkey method. Conclusions obtained from the results are as follows. 1. The assertiveness training and the value clarification training were effective in decreasing the nurse's role conflict. The value clarification was more effective than the assertiveness training in decreasing the nurse's role conflict. 2. Both assertiveness training and value clarification training were effective in decreasing nurse's communication conflict. There was, however, no differences between assertiveness training and value clarification training in decreasing the nurse's communication conflict. 3. The assertiveness training and the value clarification training were quite effective in compromizing and collaborating conflict management mode, to reducing the withdrawl and accomodate, force and accomodate conflict management mode to conflict. There was no difference in the effectiveness of assertiveness training and value clarification. In assessing the effects of the treatments, this study employed different measurements. It is unclear whether the measurement affected the test results. It is worth conducting a further test using the same measurements. The results of future studies can be compared with those of this study. The homogeneity of the control group and treatment group is questionable. Futher studies may employ homogeneous sample group to evaluate whether the sample characteristics bias the test results. Assertiveness training or value clarification training for nurses can be utilized in nursing intervention.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.469-474
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• 2007

The aim of this study was to investigate the quality changes in Supraspinatus muscle of Hanwoo with different packaging methods, such as wrapped packaging (C), vacuum packaging (V) and modified atmosphere packaging (MA). These samples were stored for 25 days under $5^{\circ}C$. Each sample was evaluated for pH, volatile basic mitrogen (VBN) value, purge loss, hardness, meat color and microbial counts. From the results obtained, no significant differences were observed among treatments at the pH. The VBN values of MA were significantly lower than those of C. Also, MA was enhanced stability of meat color compared with other packaging methods during storage days. The purge loss was the most in the V samples, followed by the C and the MA was the lowest. Total bacteria counts of MA sample were significantly lower than those from C. Therefore, it has been concluded that MA could be used as an effective packaging since it extends the shelf life and improve the quality of Hanwoo supraspinatus m.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.380-385
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• 2016

This study analyzed changes in ${\beta}$-glucan content in Agaricus blazei Murill concentrates according to extrusion and extraction conditions. Screw speed and feed rate were fixed to 250 rpm, and 100 g/min, respectively. Moisture contents (20 and 30%) and barrel temperature (130 and $140^{\circ}C$) were adjusted. ${\beta}$-Glucan content of the extruded sample at a moisture content of 20% and barrel temperature of $130^{\circ}C$ was higher compared to other extrusion conditions. ${\beta}$-Glucan content of the extruded sample at a moisture content of 20% and barrel temperature of $130^{\circ}C$ treated with Rohament CL enzyme was higher compared to Viscozyme L, and Plantase TL enzyme treatments under the same extrusion conditions. In conclusion, extrusion and pretreatment with Rohament CL enzyme enhanced yield of ${\beta}$-glucan extract.