• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.294-303
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• 2019

To extend the shelf-life of chicken breast meat, samples were treated with gel-packs containing slow-released $ClO_2$ gas at 7-15 ppm for 8 days at $4^{\circ}C$. And the changes in lipid oxidation and taste compounds of the samples were investigated. TBARS value of the chicken breast was slightly increased during storage. TBARS value of gas treatments was similar to the control during storage. There were 14 fatty acids in the chicken breast. And there was no change in the fatty acid composition during storage, and there was no significant difference between the control and gas treatments. The content of free amino acids was gradually increased during storage. The content of free amino acids were not significantly different between the control and gas treatments during storage. The content of GMP in the control and gas treatments were decreased during storage. However, gas treatments showed slightly higher content than that of control. AMP was not significantly different between the control and gas treatments. IMP gradually decreased during storage and the content of inosine and hypoxanthine was increased. IMP, inosine and hypoxanthine contents of gas treatment were similar to control, but the control tended to change more rapidly than those of gas treatments.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.2 s.30
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• pp.128-136
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• 1989

In order to investigate a practical application of fibrous adsorbents to heavy metal ions, amidoxime fibers, as a particular class of solid chelate agents, were prepared by hydroxylamine treatment for acrylic fibers in a recipe of neutralization. Among the important problems from plant effluents are toxic concentrations of heavy metals such as copper. Accordingly, the properties of Cu (II) adsorption and its chelates were studied. The results obtained are as follows; The fibrous adsorbents have the property of increasing the swelling volumes by amidoximation. The adsorption of Cu (II) ion is characterized by an endothermic reaction, which is estimated as the plus values in the enthalpy change ($\delta$H=1.30 Kcal/mol. and 3.14 Kcal/mol.). The Cu (II) ions are adsorbed in the range of pH $3\~8$ and the maximum adsorptions are occurred about pH 8. Owing to the anions $(NO_3^-,\;Cl^-)$ of copper salts, amidoxime fibers form 1:1 and 2:1 (ligand: metal) chelating complexes with Cu (II). The nitrate anion chelates to amide I (NH) of amidoxime groups and the chlorine anion does to nitrosyl (NO). These effects relate to the crystallization of the complex and the thermal property.

• Analytical Science and Technology
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• v.10 no.5
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• pp.386-394
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• 1997

The standard samples for the calibration of PIXE analysis were prepared using the single element standard samples and sulfur and chlorine compounds. The diluted standard solutions were dropped on the non-hole nuclepore film and dried. Standard sample of six elements of Ca, Cr, Co, Cu, Se and Sr had close agreement between the measurement and theoretical values. According to the theoretical study about the effects of thick samples on the accuracy of the PIXE analysis, the reduction of X-ray yields in the thick sample can not be neglected for the sample thicker than $100{\mu}g/cm^2$.

• Journal of the Korean Ceramic Society
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• v.46 no.5
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• pp.515-519
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• 2009

Carbon layers were fabricated on silicon carbide by chlorination reaction at temperatures between $1000^{\circ}C$ and $1500^{\circ}C$ with $Cl_2/H_2$ gas mixtures. The effect of reaction temperature on the micro-structures and tribological behavior of SiC derived carbon layer was investigated. Tribological tests were carried out ball-on-disk type wear tester. Carbon layers were characterized by X-ray diffractometer, Raman spectroscopy and surface profilometer. Both friction coefficients and wear rates were maintained low values at reaction temperature up to $1300^{\circ}C$ but increased suddenly above this temperature. Variation of surface roughness as a function of reaction temperature was dominant factor affecting tribological transition behavior of carbon layer derived from silicon carbide at high temperature.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.175-182
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• 1993

Volatilization of toxic heavy metals, especially, metal chlorides at elevated temperatures in oxidation conditions was observed using a thermogravimetric furnace since such metal chlorides used to be a cause for the disease of industrial workers by their toxicity and high volatile extent. Most of tested metal chloride compounds were evaporated or decomposed into gas phase at elevated temperatures ranged from 200~90$0^{\circ}C$, while CrCl$_3$ and NiC1$_2$became stable with converting into oxide forms. A kinetic model for evaporation/condensation could predict maximum evaporation flux and the calculated values were compared with real evaporation flux. The ratio of two fluxes could be explained as the fraction of impinging gas molecules to the condensing surface( $\alpha$ ) and obtained in the range of 10$^{-3}$ ~10$^{-9}$ for the experimented toxic heavy metal chlorides. This ratio might be used to define the volatile extent or toxicity of such toxic metal compounds. The schemes to avoid volatilization of toxic heavy metals Into the atmosphere were suggested as follows ; 1 ) controlling the compositions of metals and Chlorine produced substances( such as PVC ) in the treated materials using a reverse estimation from regulatory limit and characteristics of a processing facility, 2) Installation of wet type devices such as a scrubber for condensing the metal compounds.

• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.153-165
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• 1997

Hydroxyl radicals were detected and their qualitative yields were estimated by using chemiluminescence method and $\gamma$-irradiation technique in oxygen or chlorine dioxide radicals bleaching conditions. The correlation of hydroxyl radical formation and lignin model(Apocynol) or carbohydrate model($\alpha$-D-glucopyranose and methyl-$\beta$-D-glucopyranoside) degradation was studied in the presence of metal ion or without metal ion. The results showed that the presence of metal ions efficiently affected the formation of hydroxyl radicals in oxygen bleaching process, in the order of $Cu^{2+}$ > $Mn^{2+}$ > $Mg^{2+}$ > $Fe^{2+}$, and these metal gave also rise to the degradation of carbohydrate. But it was found that the addition of $100{\mu}m\;Mg^{2+}$ gave an efficient protection against carbohydrate degradation and suppressed the hydroxyl radical formation under oxygen bleaching conditions. And the presence of $Cu^{2+}$ had a detrimental effect on the stability of carbohydrates, whereas the addition of $3{\mu}m\;Mn^{2+}$ surprisingly had a small protective effect on methyl--$\beta$-D-glucopyranoside. In the $ClO_2$ radical bleaching conditions the hydroxyl radical expected to generate from water or substrates was not detected in the presence of metals.

• Journal of Dairy Science and Biotechnology
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• v.41 no.4
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• pp.203-210
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• 2023

Bacterial contamination negatively affects the quality, functionality, and safety of dairy products. Adherent populations of bacteria, referred to as biofilms, grow on the surfaces of dairy processing equipment and are the primary cause of dairy contamination. In addition, microorganisms present in the farm environment and dairy factory can contaminate the Clear-In-Place (CIP) line through raw milk transport pipes; therefore, exhaustive management is required. In dairy manufacturing facilities, biofilm formation is controlled using CIP systems that primarily require sodium hydroxide and nitric acid. However, the leakage or incomplete removal of these potently active compounds can be harmful to humans. In the present study, we compared the eradication of Escherichia coli and other bacteria using commercially available combinations of sodium hypochlorite (NaClO) and citric acid, which are recognized by the Korean Ministry of Food and Drug Safety (MFDS) as food disinfectants. When considered in the CIP system of the field manufacturing process, E. coli was not detected (compared to detection before treatment), and other bacteria were detected at 0-32 culture-forming units (CFU)/cm². The residual amount of chlorine ions after CIP treatment was similar to that in tap water, and there was no significant difference in the overall components of the fermented dairy products. Therefore, the NaClO/citric acid CIP system can be safely applied in dairy manufacturing processes.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.291-300
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• 1982

In order to develop effective and simple sanitation method for the extention of shelf-life of fresh poultry meat, the effect of sanitizers, sanitation methods and packaging materials on the extention of shelf-life of poultry meats was observed at the $4^{\circ}C$ and room temp$(10{\sim}20^{\circ}C)$. The results are summarized as follows: 1. The autochonous skin microflora of poultry, before processing, were believed to be removed or killed during the scalding and plucking, and exposed dermal tissue was contaminated by microorganisms from the subsequent stages of processing. 2. In the final stage of poultry processing, total viable counts of microorganisms and coliforms were averaged to $3.5{\times}10^4/cm^2$ and $400/cm^2$, respectively. 3. The refrigerated shelf-life of fresh whole poultry carcasses at $3\;to\;4^{\circ}C$ was extended to 7 to 16 days compared to control with the various treatments of some sanitizers by dipping freshly chilled carcasses for 5 min or spraying 1 liter of sanitizers per carcasses. In the case of storage at $10\;to\;15^{\circ}C$, the shelf-life of poultry carcasses was extended to one to two days by the sanitation treatments compared to control. 4. Spraying sanitation was more effective than dipping sanitation, and 5 minutes dipping and one liter spraying per carcass were enough for effective sanitation of poultry carcasses in most sanitizers. 5. The packaging with an oxygen impermeable polyvinylidene chloride extended the shelf-life to 10 days and 5 days with polyethylene compared to control. When poultry carcasses were sanitized by continuous spraying with one liter of 30 ppm of chlorine and another one liter of 5% of potassium sorbate, packaged with polyvinylidene chlorlde were extended to about 30 days compared to control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.479-482
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• 1991

The medical use of Acer mono MAX. and Betula costata T. sap has had the long history in Korea. So the mineral and sugar contents of these sap gathered in Mt. Jiri area at spring were analyzed to investigate the scientific base of folk remedies by using ion liquid chromatography and high performance liquid chromatography. The values of chlorine and sulfate in Acer mono MAX. were 11.5 mg/l and 176.7 mg/l, and in Betula costata T. 26.5 mg/l and 162.4 mg/l, respectively. The values of potassium, sodium, calcium and magnesium in Acer mono MAX. were 67.9 mg/l, 5.6 mg/l, 73.8 mg/l and 4.5 mg/l, and in Betula costata T. were 152.1 mg/l, 9.7 mg/l, 39.2 mg/l and 5.7 mg/l, respectively. The values of copper, zinc and manganese in Acer mono MAX. were 0.057 mg/l, 0.483 mg/l and 5.071 mg/l, and copper, zinc, mangances and iron in Betula costata T. were 0.038 mg/l, 1.584 mg/l, 4.354 mg/l and 2.511 mg/l, respectively. The values of sucrose in Acer mono MAX. were 27.29 mg/l, glucose and fructose in Betula costata T. were 0.97 g/l and 3.05 g/l, respectively.

• Journal of Environmental Health Sciences
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• v.3 no.1
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• pp.48-52
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• 1976

A study was carried out to investigate the sanitary condition of 107 wells in Jungil Ri, Kyunggi province and Daeso Ri, Choongbuck province, from July 1, to August 30, 1975. In this study, coliform groups were examined by the membrane filter method as well as general sanitary condition, pH value, ammonia nitrogen, hardness and water temperature. The following results were obtained: 1. Average value of general sanitary condition in the wells were 15$\circ$C in temperature, pH 6.4, hardness 124ppm and Cl ion 34ppm. 2. Coliform group was positive at all out of 30 open wells and 33 out of 45 pumped wells, while only 7 out of 32 tap water in the simple typed water supply system showed the evidence of coliform groups. 3. The positive rate of ammonia nitrogen revealed 13% out of 107 wells and that of nitrite nitrogen was 36.4% and 6 wells rate of 5.6% were ammonia nitrogen and nitrite nitrogen positive at same time. 4. Colflorin group positive of 32 tap water in the simple typed water supply system 3(27%) out of 11 samples with no residual chlorine, 3(17%) out of 17 with 0.1 to 0.5ppm, 1 out of 3 with 0.6 to 1.0 ppm and none out of 1 with 1.1 to 1.5 ppm.