• The Korean Journal of Malacology
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• v.17 no.1
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• pp.35-44
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• 2001

This research was conducted to develop seedling production techniques in flat oyster, Ostrea dense lamellosa. The cultivation of larvae, artificial spat and spats collection in natural conditions rate were examined. In the mass culture tank (3 tons), average growth rates of the D Shape larvae of initial shell length (153.4 ㎛) and shell height (153.4 ㎛) were 202.6% and 212.9% at 16 days and 227.1%, 241.8% at 20 days, respectively. Instantaneous death and survival rate of the larvae were 0.160 and 54.8% at 16 days and 0.057 and 43.2% at 20 days, respectively. Collection rate of flat oyster from bottom using various collectors with oyster shell, scallop shell, ark shell and PVC plates were 32.9%, 24.1%, 16.8% and 10.0%, respectively. and the greatest collecting rate was 131.9 individuals/shell (32.9%) in laid collectors on the bottom. The collecting rate of the oyster larvae were better in laid collectors on the bottom 83.8 individuals/collection than in the suspended string 54.2 individuals/collection. in all collecting substrates. Early spats settled on collectors were grew to 2.38 $\pm$ 0.97 ㎜ in shell length and 2.16 $\pm$ 0.86 ㎜ In shell height at 26 days. The spats were grew to 28.58 $\pm$ 2.39 ㎜ in shell length and 31.65 $\pm$ 2.03 ㎜ in shell height during the 4 month mid-term cultivation. In the period of cultivation, the mean number of spats attached to collectors were 10.3 individuals at oyster shells, 5.8 scallop shells, 4.0 ark shells and 1.5 PVC plates, respectively.

• Particle and aerosol research
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• v.17 no.2
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• pp.21-27
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• 2021

We developed non-metallic electrodes that can replace metallic electrodes of the electrostatic precipitator(ESP) for the purpose of light weight, corrosion resistance, cost reduction. We manufactured three types of collection electrodes made of stainless steel (M), Carbon ink coating layer-Plastic sheet-Carbon ink coating layer (CPC), and Plastic sheet-Carbon ink coating layer-Plastic sheet (PCP). We studied the collection efficiency of a two-stage ESP using oil mist particles with and without collection stage by changing the flow rate, the material of collection electrode, and the applied voltage of the pre-charger module and the collection module. Here we measured concentrations of particles at diameters of 0.45 ㎛ (CMD; count median diameter) and 3.0 ㎛ (MMD : mass median diameter), as well as PM_2.5 and PM₁₀. As a result of the experiment, two-stage ESP had 22~25% higher collection efficiency in PM_2.5 than one-stage ESP at the same applied voltage. The difference in collection efficiency by varying the materials of collection electrodes was less than 5%. The weight of the non-metallic electrode was only one eighth the weight of the metal electrode. CPC electrode had a thickness of 0.27 mm, which was 1.5 times thinner than a thickness of PCP electrode, so when the flow rate increased, the CPC electrodes couldn't be kept at equal intervals due to the fluttering unlike PCP electrodes. In addition, the PCP-CPC collection module of the present experiment followed the theoretical efficiency based on Deutsch equation and Cochet's charging theory.

• Journal of Embryo Transfer
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• v.23 no.3
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• pp.161-166
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• 2008

The techniques for the collection, cooling and freezing of semen and artificial insemination of horses are not fully understood in Korea. We investigated the percentages of total motile (TM) and progressively motile (PM) sperms after the collection, cooling and freezing of stallion semen. The average volume of semen was 167 ml in Thoroughbred and 68 ml in Arab. The average numbers of spermatozoa in Thoroughbred and Arab were $104\times10^6/ml$ and $86\times10^6/ml$ respectively. The average percentages of TM and PM were 82.3% and 88.6% in Thoroughbred, and 61.4% and 82.6% in Arab, respectively. The average percentage of TM at 4 hr after cooling at $5^{\circ}C$ was significantly lower than that at 0 hr ($30.0\pm4.1%\;vs.\;78.0\pm2.5%,\;p<0.05$), but the percentage of PM was similar between 66.5 and 73.2% at 0, 1, and 4hr. The average percentage of frozen-thawed Thoroughbred semen frozen in MFR5 extender was 56.2%, which was significantly higher than that of the semen frozen in LE extender (average 32.9%, p<0.05). The percentage of TM in Arab was similar for semen frozen in MFR5 extender and LE extender (18.2% and 21.2%, respectively), but the percentage of PM was significantly higher in sperm frozen in MFR5 extender than in sperm frozen in LE extender (69.0% vs. 36.4%, p<0.05). Four mares were artificially inseminated by Thoroughbred frozen-thawed semen and one of them fertilized at 11 day after artificial insemination. In this study, the collection, cooling and freezing of equine semen were possible under domestic conditions.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.287-293
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• 2000

This study was undertaken to access the effects of collection method, room temperature at oocyte recovery and culture media on the oocyte quality, fertilization and cleavage rates of in vitro matured and fertilized oocytes of Korean native goats. Ovaries obtained from a slaughterhouse were transported to the laboratory and were divided into 2 groups. One group of ovaries was maintained at 30 to 35$^{\circ}C$ of the room temperature and another group was remained at 20 to $25^{\circ}C$ during oocyte recovery. The oocytes were recovered by follicle aspiration, slicing and aspiration+slicing methods from 3 groups of follicles according to size; <2 mm, 2 to 6 mm and >6 mm. The matured oocytes were inseminated with buck epididymal spermatozoa at a concentration of 3~3.5$\times$10$^{6}$ m1 and fertilization was identified when 2 pronuclei were present in the cytoplasm. Although the recovery rate per ovary obtained by the combination of follicle aspiration + slicing(19.6$\pm$2.2) method was higher than aspiration(11.7$\pm$1.1) and slicing(14.8$\pm$1.8) collection, optimal recovery according to oocyte grades resulted form ovarian slicing compared to aspiration or combined methods(P<0.05). However, no significant differences were found in the mean number(2.5$\pm$1.8; 3.3$\pm$3.3; 2.9$\pm$2.4) and the proportion of favorable oocytes(Grades I, II and III) recovered(31.6%, 36.0%, 36.4%,) according to follicle size(<2 mm; 2 to 6 mm; >6 mm). Fertilization rate was 60.0%, 67.7%, 70.6% and 56.4% and the proportion of embryos/zygotes was 11.1%, 7.1%, 5.0% and 2.8% in 20~$25^{\circ}C$/BO, 30~35$^{\circ}C$/BO, 20~$25^{\circ}C$/TALP and 30~35$^{\circ}C$ /groups, respectively.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.219-222
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• 2007

These study was carried out to investigate the effects of the collection time, culture time and activation of canine oocytes on in vitro maturation rates. The activated oocytes were cultured in 10% FCS+TCM-199 media containing hormonal supplements (10 IU/ml HCG, 10 IU/ml PMSG, 10 ug/ml gonadotropin) at 5% $CO_2$, 95% air, $38^{\circ}C$. 1. IVM rate of in vitro cultured cumulus-attached oocytes recovered from ovaries that collected at follicular and luteal stages of the reproductive cycles were 11.4% and 5.7%, respectively. IVM rate of oocytes recovered from ovaries that collected at follicular stages of the reproductive cycles was significantly higher than that of luteal stage (p<0.05). 2. When IVM was carried out at different periods of 40, 48, and 70 hrs, the IVM rates of oocytes matured in vitro were 2.9%, 8.6%, 5.7%, respectively. These results indicate that the IVM time between $48{\sim}70$ hrs gives the highest maturation rate for the oocytes matured at the different stages. 3. IVM rate of oocytes matured in vitro for 10 hrs after single and combined activation treatment by ET, IP and CH and Ca+DMAP, CH+DMAP, ET+CH were $11.5{\pm}1.2%,\;10.8{\pm}1.0%,\;9.6{\pm}1.2%\;and\;12.4{\pm}1.5%,\;11.8{\pm}1.5%,\;11.2{\pm}1.4%$ respectively. This was higher than that in both single and combined stimulated groups compared to control group ($6.2{\sim}7.2%$).

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.55-60
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• 2011

The objective of this study was carried out to evaluate the efficiency of sperm collection methods on the post-thaw viability of cat semen. The cat semen was collected by artificial virginal (AV) and electronic ejaculate (EE) methods. The composition of semen extender was consisted of Tris-buffer supplemented with 20% egg yolk and 1% P/S antibiotics in Ext I, and more added 8% glycerol, 1.0% Equex STM paste of total volume in Ext II. The collected semen was adjusted the concentration and then diluted in Ext I for optimal concentration. The diluted semen was cooling to $5^{\circ}C$ temperature in refrigerator for at least 2 hrs and then diluted stepwise with Ext II for at least 1 hrs. After an equilibration for 1 hrs, the cooled semen was packaged in 0.5 ml straw and then freezing on the $LN_2$ vapor over 5 cm above from $LN_2$ and then immersed directly in $LN_2$ for cryopreservation. The frozen semen was thawed in $38^{\circ}C$ water for 15 sec and then evaluated the motility, viability, and morphology. Post-thaw semen were calculated the motility by SMI (sperm motility index). The live-dead sperm was evaluated by Eosin-B and morphological evaluation was by Diff-quik kit staining. The post-thaw concentration ($89{\times}10^6$ /ml vs. $128{\times}10^6$ /ml), viability ($22.6{\pm}10.6%$ vs. $37.1{\pm}26.1%$), morphological normality ($27.0{\pm}50.2%$ vs. $45.6{\pm}123.0%$) of EE and AV groups were not significant different, but the post-thaw motility was significant lower in EE than that in AV group ($53.1{\pm}3.6$ vs. $73.6{\pm}5.7$) (p<0.05). In conclusion, semen collection methods did not significant different between EE and AV groups except of post-thaw motility and so both semen collection methods could be applied in feline semen collection methods.

• Particle and aerosol research
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• v.14 no.4
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• pp.89-95
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• 2018

People's environmental concerns for fine particles in Korea lead to the strong necessity of improving the performance of environmental control systems. Wet electrostatic precipitators (ESPs) are considered as one of the alternatives to overcome the limit of previous dry ESPs, the re-entrainment of collected particles during rapping and back corona problem for high electrical resistivity dusts etc. In this study, a wire-cylindrical ESP with a thin water film has been developed. Particle collection characteristics were compared in the ESP with operations of water film on and off. Particle collection efficiencies at various applied voltages as well as voltage-current curves were almost the same in the ESP with and without a water film. Particle collection performance for PM1.0, PM2.5 and PM10 in the wet ESP with a water film was constantly maintained with operation time even in the high dust loading environment. This results indicate that a uniform water film in our wet ESP was successfully formed with a very thin layer without any dry spot and therefore could continuously clean the collected particles on the inner wall of the ESP without any performance degradation.

• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.126-133
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• 2019

Objectives: In this study, a nine-stage cascade impactor was used to collect dust, and the concentration of $PM_{2.1}$ & $PM_{10}$ and alveolar deposition ratio were investigated. Methods: This study was conducted at Kunsan National University from May to June 2016. A nine-stage Cascade Impactor was used to analyze the concentrations of fine and ultrafine dust and to estimate the alveolar deposition rate by particle size of atmospheric dust particles. The pore size of each stage of the collector used in this study gradually increased from F to 0, with the F-stage as the last stage. Results: The mass fraction of PM showed a bimodal distribution divided into $PM_{2.1}$ & $PM_{10}$ based on $2.1-3.1{\mu}m$. The average mass fraction of particulate matter in the range of $2.1-3.1{\mu}m$ was 44%, and the area occupied by $PM_{2.1}$ was similar. Therefore, the Gunsan area is considered to be a region where there are similar effects from anthropogenic and natural sources. Conclusion: Dust collecting efficiency increased with the stage of collecting fine dust, and the efficiency of collection was very low at the stage of collecting ultra-fine dust. The seasonal overall efficiency of the Cascade Impactor was 44% in spring and 37.4% in summer, and the average overall efficiency was 40.7%. The alveolar deposition rate of $PM_{2.1}/PM_{10}$ during the sampling period was estimated to be about 75% deposited in the alveoli.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.709-715
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• 1993

This study was carried out to estimate the relationship among dietary intakes, blood levels, and urinary excretions of Ca, P, Mg and serum lipid levels in 30 healthy adults living area of Korea(12males and 18 females). Analyses for the nutritional status of the subjects were performed by 3-day dietary intake record, duplicated diet collection, 24-hours urine collection, and venous blood sampling before anthropometry. The mean daily intakes of Ca, P and Mg estimated for 3 days were 452.5$\pm$159.5mg, 725.6$\pm$ 567.8mg and 240.4$\pm$78.5mg and the serum concentrations of Ca, P and Mg were 8.9$\pm$ 0.5mg / dl, 3.3$\pm$0.6mg / dl, and 2.1$\pm$0.8mg /dl, respectively. The 24-hour urinary excretions of Ca, P and Mg were 80.4$\pm$24.0mg, 399.0$\pm$161.1mg and 64.8$\pm$35.3mg, respectively. The serum concentrations of total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol were 158.8$\pm$32.9mg/dl, 95.6$\pm$43.9mg/dl, 45.7$\pm$9.9mg/dl and 92.2$\pm$ 28.5mg/dl, respectively. In the relation between Ca, P, Mg and serum lipids it showed positive correlation with serum Ca and HDL-cholesterol at the level of significance of 5%. It can be concluded that the high level of Ca in serum may be useful in the prevention of cardiovascular disease, but the study verifies the need for more systematic studies.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.307-314
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• 2013

Embryos formed in vivo were collected from 171 donors housed in Chung Cheong Buk-Do Institute of Livestock and Veterinary Research of the Chungbuk community during the years 2009~2012. We evaluated annual embryo collection, effect of follicle stimulating hormone (FSH), controlled internal drug release (CIDR) and prostaglandin (PG) administration to the donor for superovulation and controlling the estrus cycle, seasonal effects of embryo collection and compared the number of embryos recovered as per the collection days and pregnancy rate. In all, 1,243 embryos were collected from 118 donors with an average of $7.31{\pm}5.35$ embryos per donor, out of which 69.4% were transferable. Dosages of FSH required for inducing superovulation in various donors were compared. Average number of embryos collected from donors administered with 30 AU of FSH ($7.13{\pm}5.74$ per donor) was not significantly different from that of donors who were given an injection of 24 AU of FSH ($7.53{\pm}4.91$ per donor). However, the percentage of transferable embryos in the 30AU FSH-administered group (63.2 %, 449 of 711) was higher than that in the 24AU FSH-administered group (77.8%, 414 of 532). In the group of donors under a natural estrus cycle, the FSH dose administered did not influence the number of transferable embryos produced ($7.49{\pm}6.25$ per donor for 30 AU of FSH vs $7.49{\pm}4.92$ per donor for 24 AU of FSH). However, in donors administered with CIDR and PG for controlling the estrus cycle, the FSH dose affected the average number of transferable embryos collected ($4.25{\pm}2.87$ per donor for 30 AU of FSH vs $8.50{\pm}6.36$ per donor for 24 AU of FSH). We collected embryos from donors 6, 7 or 8 days after artificial insemination (AI). Results showed that the percentage of transferable embryos among those collected 8 days after AI was significantly higher than that among embryos collected 6 or 7 days after AI. Seasonal variations did not affect number of recovered embryos and pregnancy rates in natural estrus cycle and CIDR treatment groups (48.28% and 42.55%) but higher than pregnancy rate of frozen embryos (19.63%). These results indicated that administration of FSH beyond a threshold dose (at least 24 AU) has no beneficial effect on the production embryos and that collection of embryos 7~8 days after AI is optimal for embryo recovery. CIDR treatment induced superovulation in short term and had no influence on the natural estrus cycle. Finally, although good-quality embryos were transferred, freezing significantly reduced the pregnancy rates after transfer.