• Journal of Nutrition and Health
• /
• v.28 no.7
• /
• pp.612-619
• /
• 1995

This study was to investigate the intake of human milk, sodium and potassium of breast-fed infants at 7, 15, 30, 60 and 90 days postpartum. Milk samples were obtained from 20 healthy lactating women living in In-Cheon area. Milk intakes of 20 breastfed infants were determined by the test-weighing method and soldium and potassium contents of human milk were analyzed by Atomic Absorptin Spectrophotometer after Wet-Digestion. Infant milk intakes per day tended to increase during lactation. The mean($\pm$SD) intakes at 7, 15, 30, 60 and 90 day were 460(164), 547(202), 626(199), 718(139) and 688(162)g/day, respectively. The sodium contents decreased significantly from 9.7(1.1)mEq/kg at 7 day to 6.3(1.8)mEq/kg at 90 day(p<0.05). The sodium intakes of infants were 100.8(39.6), 103.3(46.7), 107.2(47.9), 115.5(41.5) and 105.2(41.2)mg/day, respectively and average intake was 107.2(43.9)mg/day. The potassium contents were ranged from 10.5(1.3) to 13.3(2.3) mEq/kg and the potassium intakes of infants were 241.8(11.2), 267.8(98.8), 314.1(98.6), 318.0(66.1) and 276.1(62.6)mg/day, respectively and average intake was 288.3(91.8)mg/day. The mean sodium and potassium intakes of infants between boys and girls were not significantly different at 5% level.

• Environmental Engineering Research
• /
• v.25 no.1
• /
• pp.123-128
• /
• 2020

Non-point source pollutant load reductions were calculated using the Hydrologic Simulation Program-Fortran (HSPF) model under the assumption that landuse pattern was changed according to land purchases. Upon the simulation of non-point pollutant and areas with high land purchase ratios to select a buffer zone, the Namgang dam Reach 11, Imha dam Reach 10, and the Reach 136 watershed of the main river were found to rank high for the construction of buffer zones. Assuming that the forms of the purchased lands were changed to wetlands, biological oxygen demand (BOD) loads were changed through the HSPF model. No changes of BOD were present in the Namgang dam and the Imha dam watersheds. BOD loads in Reach 136 according to landuse change were analyzed through a flow duration analysis based on the total maximum daily loads of the United States. The flow duration analyses undertaken to examine changes in BOD of main river Reach 136 watershed indicated a shift of 0.64 kg/d from 3.16 to 2.52 during high flow. The change of BOD under the conditions of moist, mid-range and dry were 11.9%, 9% and 4.5%. At the low flow condition, the variation range in the BOD load was from 0.58 kg/d to 0.41 kg/d.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.34 no.2
• /
• pp.105-116
• /
• 1998

This paper, examines the relationship between water temperatures and fishing conditions of common squid by the squid angling fishery from June to September in 1993-1995. The condition of the common squid fishing largely depended on the fluctuation of water temperature in the coastal area of Gampo. Monthly mean water temperatures during June m September in 1993 and 1994 were relatively higher than those in 1995 in Gampo area. But the values between July and August in 1995 were about 5$^{\circ}C$ lower than those in 1993 and 1995. Coefficients of variation (CV) of water temperature showed the lowest value during July ~ September in 1993, however, the highest value was observed in July and August in 1994. Catch per unit effort (CPUE ; kg/angling) showed a peak with 73.7kg in 1993 when the CV was low. On the other hand, the lowest CPUE of 39.6kg was observed in 1994 when the CV was high. It was concluded that the high stability of water temperatures and the weak strength of cold water have caused the good fishing conditions of common squid.

• Journal of Veterinary Clinics
• /
• v.20 no.1
• /
• pp.104-109
• /
• 2003

This study was performed to evaluate the postoperative heating process according to lameness degree, swelling, and muscle atrophy after femoral head and neck ostectomy on Retriever dogs with hip dysplasia and hindleg lameness. Femoral head and neck ostectomy (FHO) was performed for the repair of hip dysplasia in 4 Retriever dogs (5 hips) referred in veterinary medical teaching hospital of college of veterinary medicine, Konkuk University. Age (Mean $\pm$ SD) of patients was 10.3 $\pm$ 3.0 months (range,7 to 16 months) and body weight (Mean $\pm$ SD) was 28.2 $\pm$ 3.4 kg (range, 25 to 34 kg). After FHO, all cases are treated with carprofen (2.2 mg/kg, PO bid, tapering at interval 1-2 weeks) and physical therapy including passive range-of-motion exercises. In all cases, lameness degree was showed V at the next day after surgery, IV at 5 to 7 days, II-III at 30 to 35 days, II at 60 days, and I at 105 to 114 days. These results suggested that femoral head and neck ostectomy was able to be performed on large breed dogs with hip dysplasia and hindleg lameness.

• Korean Journal of Environmental Agriculture
• /
• v.6 no.1
• /
• pp.17-24
• /
• 1987

Benzene-ring-labelled $^{14}C-Bentazon$(3-isopropyl-2, 1, 3-benzothiadiazin-4-one-2, 2-dioxide) incubated aerobically in a German and a Korean soil at application rates of 5.51 and 25.05mg/Kg was mineralized to $^{14}CO_2$ at average rates of 0.6% and 0. 2%/week, respectively, in both soils, in the absence of plants. Distilled water was the most suitable solvent for the extraction of Bentazontreated soils. Extraction results disclosed that higher percentages of nonextractable residues were formed in the lower concentration of 5.51mg/Kg than in the higher concentration of 25.05mg/Kg, relative to the initial concentrations.

• Journal of Radiation Industry
• /
• v.10 no.4
• /
• pp.173-179
• /
• 2016

Coals and coal ashes, raw materials and by-products, in coal-fired power plants contain naturally occurring radioactive materials (NORM). They may give rise to internal exposure to workers due to inhalation of airborne particulates containing radioactive materials. It is necessary to characterize radioactivity concentrations of the materials for assessment of radiation dose to the workers. The objective of the present study was to analyze radioactivity concentrations of coals and by-products at four coal-fired plants in Korea. High purity germanium detector was employed for analysis of uranium series, thorium series, and potassium 40 in the materials. Radioactivity concentrations of $^{226}Ra$, $^{228}Ra$, and $^{40}K$ were $2{\sim}53Bq\;kg^{-1}$, $3{\sim}64Bq\;kg^{-1}$, and $14{\sim}431Bq\;kg^{-1}$ respectively in coal samples. For coal ashes, the radioactivity concentrations were $77{\sim}133Bq\;kg^{-1}$, $77{\sim}105Bq\;kg^{-1}$, and $252{\sim}372Bq\;kg^{-1}$ in fly ash samples and $54{\sim}91Bq\;kg^{-1}$, $46{\sim}83Bq\;kg^{-1}$, and $205{\sim}462Bq\;kg^{-1}$ in bottom ash samples. For flue gas desulfurization (FGD) gypsum, the radioactivity concentrations were $3{\sim}5Bq\;kg^{-1}$, $2{\sim}3Bq\;kg^{-1}$, and $22{\sim}47Bq\;kg^{-1}$. Radioactivity was enhanced in coal ash compared with coal due to combustion of organic matters in the coal. Radioactivity enhancement factors for $^{226}Ra$, $^{228}Ra$, and $^{40}K$ were 2.1~11.3, 2.0~13.1, and 1.4~7.4 for fly ash and 2.0~9.2, 2.0~10.0, 1.9~7.7 for bottom ash. The database established in this study can be used as basic data for internal dose assessment of workers at coal-fired power plants. In addition, the findings can be used as a basic data for development of safety standard and guide of Natural Radiation Safety Management Act.

• Journal of Embryo Transfer
• /
• v.27 no.2
• /
• pp.101-105
• /
• 2012

Linuron is a pesticide with a weak anti-androgenic property, which impacts male reproductive organs. In this study, to clarify whether linuron affects the cellular antioxidant system of ventral prostate, gene expression patterns of the representative antioxidant enzymes such as glutathione peroxidase (GPx), selenoprotein P (SePP), and superoxide dismutase (SOD) were investigated in the rat ventral prostates exposed to linuron using real-time RT-PCR analyses. Sprague-Dawley rats castrated at 6 weeks old were treated with linuron (25, 50, or 100 mg/kg per oral) daily for 10 days after testosterone propionate administration (0.4 mg/kg) subcutaneously. As compared to normal control animals, mRNA levels of phospholipid hydroperoxide GPx (PHGPx), SePP, and Mn SOD significantly increased in the prostates exposed to linuron (25, 50, and 100 mg/kg). However, cytosolic GPx (100 mg/kg) and Cu/Zn SOD (25, 50, and 100 mg/kg) mRNA levels significantly decreased in the ventral prostates. These results indicate that linuron upregulates the expressions of PHGPx, SePP, and Mn SOD mRNAs, but down-regulates the expressions of cytosolic GPx and Cu/Zn SOD in rat prostates, suggesting that linuron may have dual effects in the cellular antioxidant system of prostate.

• Korean Journal of Veterinary Research
• /
• v.11 no.2
• /
• pp.105-116
• /
• 1971

The effects of aconite root in rats and rabbits were studied following oral administration of the powder which was prepared by lyophilization of the decoction of the salted aconite roots. The $LD_{50}$ of the powder, the blood picture, total blood volume, uptake rate of ${42}^K$ and ${24}^Na$ in various organs, oxygen consumption, thyroid activity, and histopathological changes in various organs, were observed. The results obtained were as follows: 1. The $LD_{50}$ of the powder of decoction of the aconite root was 4.07g/kg of body weight in mice which is equivalent to approximately 40g/kg of the salted aconite roots. 2. The number of erythrocytes and leukocytes, hematocrit value, and the amount of hemoglobin in blood were increased in the rats administered daily dosages of 0.1, 0.5, and 1.0g/kg respectively. No significant differences were observed in the differential count of leukocytes. A slight tendency of hemoconcentration was recognized. 3. No changes in the erythrocyte volume, plasma volume and total blood volume were observed in the rats after administration of the powder for one, three, and six days. However, those were decreased in rats treated for ten days. 4. Generally, in various organs of rats the uptake rate of ${24}^Na$ showed a tendency of increasing but that of ${42}^K$ slowed a decreasing tendency. 5. The oxygen consumption was markedly decreased in rats administered the powder. 6. Iodine-131 uptake of thyroid gland was markedly decreased in the rabbits following administration of the powder. 7. In rabbits administered 0.5g/kg for 20 days, fatty changes of hepatic cells, cloudy swelling of the epithelial cells of proximal convoluted tubules of the kidney and the dilation of splenic sinuses were observed, however, milder changes were found in rabbits treated with 0.1g/kg for the same period.

• Journal of the Korean Ceramic Society
• /
• v.13 no.1
• /
• pp.11-19
• /
• 1976

This study was focused on the improvement of production techniques of small crucibles in relation with the appropriate selection of raw materials, various batch compositions and physical and chemical characteristics of the crucibles. Various tests gave the optimum batch composition for the carbon bond graphite cructble as follows: Pyontaek graphite flake (refractory aggregate) : 40Part Silicon carbide: 15Part Tar pitch (binder) : 11Part Inorganic additives (to improve the oxidation resistance) : 15 Part Cryolite : 3 Part Ferro manganese : 2 Part Ferrosilicon : 25 Part Crucibles pressed with 400kg/$\textrm{cm}^2$ at 12$0^{\circ}C$. and fired in reducing atmosphere at 120$0^{\circ}C$ brought the most favorable results as follows: Bulk density : 2.31 Apparent density : 2.58 Porosity : 15.2% Oxidation loss at 1, 50$0^{\circ}C$. for 3 hrs : below 3.77% Water absorption : 6.01% Compressive strength : 438kg/$\textrm{cm}^2$ Tensile strength : 256kg/$\textrm{cm}^2$.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.3
• /
• pp.304-311
• /
• 2014

In this study, to apply hydrogen energy to ship engine and to generate effective hydrogen production, we investigated the effects of high temperature $H_2SO_4$ feed rate and cooling water rate to pump parts with fixed frequency needed to reciprocate motion and a simulation was conducted at each condition. In the fixed frequency and cooling water inlet flow rate of 0.5 Hz and 3.9 kg/s, we changed the high temperature $H_2SO_4$ flow rate to 47.46 kg/s (it is 105 % of 45.2 kg/s), 49.72 kg/s (110 %), and 51.98 kg/s (115 %). Also, at 0.5 Hz and 45.2 kg/s of frequency and high temperature $H_2SO_4$ flow, the thermal hydraulic analysis was performed at the condition of 95 % (3.705 kg/s), 90 % (3.51 kg/s), and 85 % (3.315 kg/s). In overall simulation cases, the physical properties of materials are more influential to the temperature increase in the pump part rather than the changes on the feed rate of high temperature $H_2SO_4$ and cooling water. A continuous operation of pump was also capable even if the excess feed of high temperature $H_2SO_4$ of about 15 % or the less feed of cooling water of about 15 % were performed, respectively. When the increasing feed of high temperature $H_2SO_4$ of up to 5 %, 10 %, and 15 % were compared with base flow (45.2 kg/s), the deviation of time period rose to a certain temperature and ranged from 0 to 4.5 s in the same position (same material). In case of cooling water, the deviation of time period rose to a certain temperature and ranged from 0 to 5.9 s according to the decreasing feed changes of cooling water at 5 %, 10 %, and 15 % compared to a base flow (3.9 kg/s). Finally, the additional researches related to the two different materials (Teflon and STS for Pitch and End-plate), which are concerned about the effects of temperature changes to the parts contacting different materials, are needed, and we have a plan to conduct a follow-up study.