• Nuclear Engineering and Technology
• /
• v.32 no.5
• /
• pp.477-484
• /
• 2000

To estimate the degree of intake of $^{238}$ U and $^{232}$ Th through daily diet, a Korean mixed diet sample was prepared after the investigation of the amount of consumption of the daily diet which corresponds to the age of 20 to 60 years. For the analysis of U and Th, the RNAA method was applied. Two standard reference materials were used for quality control and assurance and the analytical results were compared with a certified value. The determination of U and Th in the Korean mixed diet sample was carried out under the same analytical conditions and procedures with SRM. It is found that the concentration of U and Th in a Korean mixed diet was about 35.4 ppb and 3.4 ppb. From these results, the daily intake of $^{238}$ U and $^{232}$ Th by diet is evaluated to be 6.98 and 0.67 $\mu\textrm{g}$ per day, respectively. Radioactivities related to the intake of $^{238}$ U and $^{232}$ Th were estimated to be about 86 mBq and 27 mBq per person per day and the annual dose equivalents from $^{238}$ U and $^{232}$ Th revealed as 3.18 $\mu$Sv and 0.29 $\mu$Sv per person, respectively.

• Journal of Korean Society on Water Environment
• /
• v.22 no.3
• /
• pp.492-497
• /
• 2006

Feasibility of simultaneous removal of organic materials and nitrogen in the wastewater from fisheries processing plant was evaluated using entrapped mixed microbial cell (EMMC) process. The experiment was performed using activated sludge from municipal sewage treatment plant which was immobilized with gel matrix by cellulose triacetate. It was found the stable operation at the treatment system which is composed of anoxic and oxic tank, was possible when the organic and nitrogen loading rates were increased stepwise. The organic and nitrogen loading rates were conducted from 0.65 to $1.72kgCOD/m^3/d$ and from 0.119 to $0.317kg\;T-N/m^3/d$ with four steps, respectively. The maximum nitrogen loading rate which could satisfy the regulated effluent standard of nitrogen concentration, was $0.3kg\;T-N/m^3/d$. The removal efficiency of total nitrogen was decreased apparently as increasing nitrogen loading rates, whereas the removal efficiency of ammonium nitrogen was effective at the all tested nitrogen loading rates. Therefore, it was concluded that nitrification was efficient at the system. Nitrate was removed efficiently at the anoxic tank. whereas the nitrification efficiency at the oxic tank ranged 94.0% to 96.9% at the tested loading rates. The removal efficiencies of chemical oxygen demand (COD) and those of total nitrogen at the entire system ranged from 94.2% to 96.6% and 73.4% to 83.4%, respectively.

• Women's Health Nursing
• /
• v.5 no.3
• /
• pp.337-348
• /
• 1999

This descriptive study was cone to investigate the incidence of and reasons for the interruption of breast-feeding by married nurses. For this purpose, data was collected from married nurses, each of whose last child was under five years old, living in Seoul, Tong Hae, Sam Chok and Kang Rung. The number of children involved was 208. The data was collected from various places in Seoul, Tong Hae, Sam Chok and Kang Rung area, using 150 survey questionnaires. The results of the study were as follows: 1. The proportion of children receiving breast-feeding was 1.4%, mixed feeding 33.8% and milk feeding 64.9%. The most frequent duration of breast-feeding was one month (80.2%). 2. The major reasons for breast-feeding were the health of the child 97%, and for emotional attachment with the child 75%. 3. The major reasons for interrupting breast-feeding were the job of mother 79.5%, and an abnormality of the breast or nipple 26.0%. 4. The major reasons for quitting breast-feeding were the job of mother 89.2%, insufficient breast milk 34.2%, and breast pain 19.9%. The above results suggest that the breast-feeding ratio in married nurses is very low. Therefore it is recommended that education about and propagation of breast-feeding be carried out. To enhance and promote breast-feeding, hospital managers should provide a comfortable environment, which is conducive to breast-feeding.

• Journal of the Korean Chemical Society
• /
• v.28 no.3
• /
• pp.176-184
• /
• 1984

Retention behavior of benzoic acid and its derivatives on XAD-2 in the alcoholic aqueous solution was investigated and separation was attempted. Retention was affected by the concentration and kinds of added organic solvents, the pH of the aqueous solution, the added $R_4N^+$ and the position and kinds of functional group in the sample molecules. Retention of sample acids in acidic conditions was due to mainly molecular adsorption on nonpolar XAD-2 surface and that in basic conditions was due to mainly ion-pair model. In these bases a mixed sample was separated in EtOH 20% aqueous solution at pH 8.50.

• Journal of Environmental Science International
• /
• v.26 no.8
• /
• pp.967-976
• /
• 2017

In this study, the effect of probiotic supplementation on growth performance, blood metabolites, and meat quality of Hanwoo steer was investigated. A total of 32 Hanwoo steers (15-17 months, average body weight $462{\pm}37.9kg$) were randomly allotted to 4 dietary treatments (0, 0.5, 1.0, and 1.5% mixed probiotics), with four Hanwoo steers per pen (two replicates per treatments), and reared for 12 months. There were no differences among treatments in growth performance of Hanwoo steer (P>0.05); however, feed intake decreased linearly with increasing levels of mixed probiotics. Growth hormone and Blood Urea Nitrogen (BUN) levels responded linearly with increasing levels of dietary mixed probiotics (P<0.05), but not insulin and blood glucose did not. In particular, total cholesterol was significantly lower for the 1% mixed probiotic treatment in comparison with that of the other treatments (P<0.05). The pH, Thiobarbituric Acid Reactive Substances (TBARS), cooking loss, and meat color were influenced by increasing levels of mixed probiotics (P<0.05), but the carcass characteristics and shear force were not. Regarding sensory evaluation, the addition of mixed probiotics resulted in significant difference in meat color, tenderness, aroma, off-flavor, juiciness, and marbling score, but not in overall acceptability. In addition, fatty acid profiles indicated no differences between control and mixed probiotic treatments. In conclusion, mixed probiotic treatment at 1% levels can enhance consumer preferences possibly by reducing cholesterol and TBARS.

• Journal of the Korean Ceramic Society
• /
• v.41 no.12 s.271
• /
• pp.884-888
• /
• 2004

Effects of NiO were studied in aspects of dielectric properties and microstructure of $0.96(0.91Pb(Mg_{1/3}Nb_{2/3})O_3-0.09PbTiO_3)­0.04BaTiO_3$ (PMN-PT-BT, PBT). The PBT was prepared by a conventional mixed oxide method using $(MgCO_3)_4{\cdot}Mg(OH)_2$ instead of MgO through Lewis acid-base interaction. NiO was added in the range of 0.5 to $3.0\;wt\%$ as thermally decomposable $2NiCO_3{\cdot}3Ni(OH)_2$ and it seemed to enhance densification to a large extent below $1000^{\circ}C$. But all the systems gave rise to ceramics with almost same relative sintered density of 96% by sintering at $1000^{\circ}C$ for 2 h. But it turned out that the addition of NiO was detrimental to dielectric constant but beneficial to the loss of dielectric constant.

• Preventive Nutrition and Food Science
• /
• v.5 no.3
• /
• pp.165-169
• /
• 2000

Kombucha beverages were made from sweetened tea by Oriental, European and Tibetan tea fungus starters. The hot water extracts o green tea, black tea, Gugija and Omija were mixed with white and/or brown sugar, and were fermented under a static culture at 3$0^{\circ}C$. Titrable acidity, pH, color and cellulose production in kombucha beverages were evaluated. All tea fungus starters showed a higher acid production in green/black tea extracts rather than Gugija and Omija extracts. In green/black tea extracts Oriental tea fungus produced a kombucha beverage with a higher titrable acidity and lower pH than those of European and Tibetan tea fungus starters. By the static fermentation of green/black tea extract for 18 days, Oriental, Tibetan and European tea fungus starters produced cellulose pellicles of 0.43g, 0.16g, and 0.19 g (dry weight) on the top in the culture, respectively. As a mother starter, the cellulose pellicle was more efficient in acid production compared with tea fungus broth. Oriental/Tibetan mixed tea fungus showed the best acid production in the green/black tea extract supplemented with brown sugar.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.6 s.177
• /
• pp.1547-1556
• /
• 2000

In this paper, an evaluation method of fracture toughness to apply interfacial fracture mechanics was investigated in adhesively bonded double-cantilever beam (DCB) joints. Four types of adhesively bonded DCB joints with an interface crack were prepared for analyses of the stress intensity factors using boundary element method(BEM) and the fracture toughness test. From the results of BEM analysis and fracture toughness experiments, it is found that the stress intensity factor, K1 is a parameter driving the fracture of adhesively bonded joints. Also, the evaluation method of fracture toughness by separated stress intensity factors of mixed mode cracks was proposed and the influences of mode components for its fracture toughness are investigated in adhesively bonded DCB joints.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.11a
• /
• pp.113-116
• /
• 2008

In these days, properties of concrete has been demanded to be high performance because concrete structure was bigger and higher. So studies on high strength concrete and lightweight concrete has been frequently done. But lightweight concrete has been used to limited non-structural elements in th country. Lightweight aggregate mixed with lightweight concrete was only coarse aggregate in case of the structural lightweight concrete. In the country studies on the lightweight concrete was poor and unvaried. Also it is difficult to be practical use of lightweight concrete was that it has been expensive. It was study on the using fine lightweight aggregate with lightweight concrete to crushed by-products and wastes to get to make foamed glass with recycled glass. So it was tested by fine aggregate standard and mixed with.

• Journal of the Korean institute of surface engineering
• /
• v.24 no.1
• /
• pp.24-24
• /
• 1991

Cr-N films were deposited on low-carbon steel sheets by the reactive arc-induced ion plating (AIIP). The influence of the deposition conditions (nitrogen pressure and substrate bias voltage) on the crystal orientation, morphology and microhardness of the Cr-N films has been investigated using x-ray diffractometer and scanning electron microscope. The impurities and contaminations on the surface and at the interface, and the layer-by-layer compositions of the film have been analyzed using scanning Auger multiprobe (SAM) and glow discharge spectroscope (GDS). The mixed state of Cr and Cr2N turned out to have a fine fibrous structure. The Cr2N films were deposited at a wide range of nitrogen flow rates. The orientations of Cr2N films were mainly (110) and (111), and the intensity of the (111) peak increased as the substrate bias voltage increased. The micorstructure of the Cr2N film was dense and no columnar structure was observed. The films in the mixed state of Cr2N and CrN were also dense without columnar structure. The maximum microhardness of the Cr-N films was 2400 kg/$\textrm{mm}^2$ at 10gf load.