• Korean Journal of Materials Research
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• v.8 no.11
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• pp.1020-1025
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• 1998

Irradiation-induced changes in mechanical properties and magnetic parameters were measured and compared to explore possible correlations for Mn-Mo-Ni low alloy steel surveillance specimens which were irradiated to a neutron fluence of $2.3\times10^{19}n/cm^2$(E>1.0MeV) in a typical pressurized water reactor environment at about $288^{\circ}C$. For mechanical property parameters, microvickers hardness, tensile and Charpy impact test were performed and Barkhausen noise amplitude, coercivity, remanence, maximum induction were measured for magnetic parameters. respectively. Results of mechanical property measurements showed an increase in yield and tensile strength, microvickers hardness. 41J indexed $RT_{NDT}$ and a decrease in upper shelf energy irrespective of base and weld metals. However, in the case of tensile properties, the changes in weld metal were negligible compared to the base metal. In the case of magnetic measurements, it is found that magnetic remanence, BN amplitude. BN energy have dropped significantly but coercivity(H,) has increased rapidly after irradiation. In this study. the measurements conducted on surveillance specimens of Mn-Mo-Ni low alloy steel showed that there were strong correlations between mechanical properties and magnetic properties.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.285-293
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• 2015

This study was performed in order to provide better quality health care services and satisfaction, the basis for the differential rating system to be operational by identifying how to recognize and respect in hospital operating efficiently and according to the rating differential with convalescent hospital doctors and nursing staff target was. The results of this study are as follows. Rating and doctors as a result of the independent sample t-test to analyze the differences of the nursing grade, second grade doctors were able to see that higher efficiency and improve the patient's rights organization in nursing improving patient safety in two grades, improve care and patient rights this product was confirmed to be enhanced higher. Doctor and as a result of the ANOVA analysis to analyze the differences in accordance with the nursing staff level, improve patient safety, hospital finances, the hospital doctor in the first grade, Nursing grade 2, the right to improve patient education and self-development, and two doctors, nursing grade 1 in was found that high. Overall, doctors, nursing staff of higher grade, first grade and second grade is the difference between me and a different result each category future convalescent hospital doctors and nursing staff of the differential rating system 1, it is necessary to consider restructuring among a calculation based on 2 ratings there will be.

• Tribology and Lubricants
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• v.11 no.5
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• pp.128-135
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• 1995

Atomic force microscopy/friction force microscopy (AFM/FFM) techniques are increasingly used for tribological studies of engineering surfaces at scales, ranging from atomic and molecular to microscales. These techniques have been used to study surface roughness, adhesion, friction, scratching/wear, indentation, detection of material transfer, and boundary lubrication and for nanofabrication/nanomachining purposes. Micro/nanotribological studies of single-crystal silicon, natural diamond, magnetic media (magnetic tapes and disks) and magnetic heads have been conducted. Commonly measured roughness parameters are found to be scale dependent, requiring the need of scale-independent fractal parameters to characterize surface roughness. Measurements of atomic-scale friction of a freshly-cleaved highly-oriented pyrolytic graphite exhibited the same periodicity as that of corresponding topography. However, the peaks in friction and those in corresponding topography were displaced relative to each other. Variations in atomic-scale friction and the observed displacement has been explained by the variations in interatomic forces in the normal and lateral directions. Local variation in microscale friction is found to correspond to the local slope suggesting that a ratchet mechanism is responsible for this variation. Directionality in the friction is observed on both micro- and macro scales which results from the surface preparation and anisotropy in surface roughness. Microscale friction is generally found to be smaller than the macrofriction as there is less ploughing contribution in microscale measurements. Microscale friction is load dependent and friction values increase with an increase in the normal load approaching to the macrofriction at contact stresses higher than the hardness of the softer material. Wear rate for single-crystal silicon is approximately constant for various loads and test durations. However, for magnetic disks with a multilayered thin-film structure, the wear of the diamond like carbon overcoat is catastrophic. Breakdown of thin films can be detected with AFM. Evolution of the wear has also been studied using AFM. Wear is found to be initiated at nono scratches. AFM has been modified to obtain load-displacement curves and for nanoindentation hardness measurements with depth of indentation as low as 1 mm. Scratching and indentation on nanoscales are the powerful ways to screen for adhesion and resistance to deformation of ultrathin fdms. Detection of material transfer on a nanoscale is possible with AFM. Boundary lubrication studies and measurement of lubricant-film thichness with a lateral resolution on a nanoscale have been conducted using AFM. Self-assembled monolyers and chemically-bonded lubricant films with a mobile fraction are superior in wear resistance. Finally, AFM has also shown to be useful for nanofabrication/nanomachining. Friction and wear on micro-and nanoscales have been found to be generally smaller compared to that at macroscales. Therefore, micro/nanotribological studies may help def'me the regimes for ultra-low friction and near zero wear.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.390-397
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• 2010

Residual solvents in foods are defined as organic volatile chemicals used or produced in manufacturing of extracts or additives, or functional foods. The solvents are not completely eliminated by practical manufacturing techniques and they also may become contaminated by solvents from packing, transportation or storage in warehouses. Because residual solvents have no nutritional value but may be hazardous to human health, there is a need to remove them from the final products or reduce their amounts to below acceptable levels. The purpose of this study was to develop and evaluate an analytical method for the screening of residual solvents in health functional foods. Furthermore, the aim of this study was to constitute a reasonable management system based on the current state of the market and case studies of foreign countries. Eleven volatile solvents such as MeOH, EtOH, trichloroethylene and hexane were separated depending on their column properties, temp. and time using Gas Chromatography (GC). After determining the GC conditions, a sample preparation method using HSS (Head Space Sampling) was developed. From the results, a method for analyzing residual solvents in health functional foods was developed considering matrix effect and interference from the sample obtained from the solution of solvents-free health functional foods spiked with 11 standards solutions. Validation test using the developed GC/HSS/MS (Mass Spectrometry) method was followed by tests for precision, accuracy, recovery, linearity and adequate sensitivity. Finally, examination of 104 samples grouped in suits was performed by the developed HSS/GC/MS for screening the solvents. The 11 solvents were isolated from health functional foods based on vapor pressure difference, and followed by separation within 15 minutes in a single run. The limt of detection (LOD), limit of quantification (LOQ), recovery and coefficient of variation (C.V.) of these compounds determined by the HSS/GC/MS were found to be 0.1 pg/mL, 0.1-125 pg/g, 51.0-104.6%, and less than 15%, respectively. Using the developed HSS/GC/MS method, residual solvent from 16 out of 104 health functional products were detected as a EtOH. This method therefore seems t o be a valuable extension ofanalytical method for the identification of residual solvents in health functional food.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.170-174
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• 1985

This study was intended to develop a sanitary and economic storage method using gamma irradiation for chicken. The samples, which were irradiated with doses of 0, 5, 8 and 10 kGy and stored at 3 to $4^{\circ}C$ for 41 days, were subjected to an investigation of the sterilizing effect on microorganisms. In the number of microorganisms contaminated, psychrotrophiles, mesophiles and thermophiles were $7.8{\times}10^5,\;3.6{\times}10^5$ and $1.1{\times}10^3$ per gram of the samples, respectively, and yeast & mold and coliform group were $3.0{\times}10^3$ and $2.1{\times}10^3$ per gram of the samples, respectively. Also, other enteric bacilli were isolated up to 90% out of total test groups on a selective medium(S-S agar). The number of total bacteria was reduced by over 2 to 4log cycles with an irradiation of 5 kGy to 10 kGy, and an irradiation treatment of over 5 kGy was shown to be effective for the radurization of yeast & mold, coliform group and other enteric bacilli. Thus, it was possible to extend the microbiological self-life of chicken for about 2 to 7 weeks compared with the control.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.105-113
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• 2009

The freezed Mulberry (10 kg) was extracted with 80% EtOH, concentrated, and fractionated with a series of n-hexane, ethyl acetate, and water on a separatory funnel. A portion of ethyl acetate soluble (22 g) was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol as eluents. The isolated compounds were identified by cellulose TLC, $^1H-$,$^{13}C$-NMR, FAB, and EI-MS. Quercetin-3-O-${\beta}$-D-glucopyranoside (Compound I), protocatechuic acid (Compound II), p-hydroxybenzoic acid (Compound III) were isolated from the ethyl acetate soluble fraction. In antioxidative activities of the fractionated extractives using DPPH radical scavenging test, EtOAc and water soluble fractions indicated better than BHT as contro and in in vitro tests using MTT assay, there was no cytotoxicity. Also, tyrosinase inhibition and anticancer activities were not so good, but there may be a potential as a cosmetic raw material because the cell extension effect was excellent.

• Journal of Life Science
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• v.14 no.2
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• pp.286-290
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• 2004

The antioxidant activities of the various fractions extracted from mustard leaf (Brassica juncea) and mustard leaf kimchi were determined by the radical scavenging effect on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. The fractions from dried mustard leaf, and fermented mustard leaf kimchi for 0 day and fermented mustard leaf kimchi for 5 days at 15$^{\circ}C$ were screened for the scavenging effects by using DPPH assay. The fractions prepared by the systematic extraction procedure with the solvents such as hexane, C $H_2$Cl$_2$, EtOAc, BuOH and $H_2O$ were used for the determination of free radical scavenging effects. The antioxidant activity of EtOAc and n-BuOH soluble fraction from mustard leaf and mustard leaf kimchi for 0 day had stronger than the others. During fermentation at 15$^{\circ}C$ for 5 days, the antioxidant activity was changed. C $H_2$Cl$_2$ and EtOAc soluble fraction showed more potent radical scavenger effects than the others. The difference or results were to the various supplements and fermentation process.

• Journal of Korean Academy of Nursing
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• v.38 no.6
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• pp.822-830
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• 2008

Purpose: The purpose of this study was to analyze effects of a community-based case management program for clients with hypertension living in the community. Methods: The research design was a one group pre and post-test design with 30 participants with hypertension who agreed to participate in the 8-12 week case management program provided by case managers from the National Health Insurance Corporation in 2002. Data were collected three times, before and after the case management services, and 6 months later. Outcomes included changes in blood pressure, knowledge of hypertension and daily life practices, including alcohol consumption, smoking, exercise, and medication adherence. Results: Repeated-measures ANOVA and post-hoc tests of means revealed significant differences before and after service for systolic blood pressure, daily life practices (monitoring body weight and BP, low salt and cholesterol and high vegetable diet, and stress-relief practices), and exercise. The goal for medication adherence was attained after service. Significant improvements from baseline to 6 months after service were observed in measures of salt and vegetables in diet. There were no significant differences on hypertension knowledge, alcohol consumption or smoking behavior between before service and after, and at 6 months. Conclusion: The findings provide preliminary evidence that case management intervention can have positive outcomes on BP control, daily life practices, exercise, and medication adherence for clients with hypertension. However, additional interventions are needed to sustain long-term effects.

• Food Science and Preservation
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• v.15 no.3
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• pp.456-460
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• 2008

Santalum album has been used as a folk medicine for treatment of skin diseases, inflammation, gonorrhea, gleet, and cystitis in India and other Asian countries. In a search for possible bioactive agents from natural sources, we found that the various solvent extracts of S. album showed significant antioxidative effect in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity test and moderate other biological functions submitted to the several bioassay systems for whitening and cytotoxicity evaluations. Among the tested extracts displayed DPPH radical scavenging activity, and the 70% acetone extract showed the most potent activity with an $IC_{50}$ value of $18.6\;{\mu}g/ml$, more potent than a positive control, L-ascorbic acid ($IC_{50}$, $28.7\;{\mu}g/mL$). Also, anti-lipid peroxidation, tyrosinase inhibitory, and cytotoxic effects were determined in each experiment. Total phenolic content of 70% acetone extract was found to be 117.1 mg equivalent of gallic acid per g of extract. Previous phytochemical investigation reveals the presence of phenolic compounds. The results indicate that S. album possess potential antioxidant activity and phenolic constituents are responsible for this capacity.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.14-21
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• 2015

To determine residual characteristics of azoxystrobin in ginseng under different cultivation conditions such as use of straw mat on cultivation soil and filling gap between ginseng stem and soil surface and also to elucidate its approximate behavior after spraying, 20% azoxystrobin suspension concentrate solution was sprayed 4 times onto 5-year-old ginseng with 10 days interval at a application rate of about 200 L/10 a and then residues in samples were analyzed. The residue level was lower in case of use of straw mat and filling the gap with soil than in case of no use of straw mat and no filling the gap, representing that use of straw mat and filling the gap with soil were contributed to decrease of pesticide residues in ginseng. A large portion of the test pesticide distributed onto ginseng leaf with a higher specific surface area. The amounts of azoxystrobin residues decreased in ginseng leaf, while increased on soil surface, as close to harvest. About 0.1% of azoxystrobin sprayed was distributed in ginseng root and 12.7-20.4% (mean 16.6%) of azoxystrobin could be decreased for dietary intake by removing of rhizome from ginseng root before intake.