• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.612-616
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• 2004

This study was carried out to compare the semen characteristics, frozen-thawed sperm viability and testosterone concentration and in vitro fertilization (IVF) and development of in vitro matured pig oocytes between two Yorkshire boars. Semen and blood samples were collected once per week from October to November 2002 from two adult Yorkshire boars at 18 months of age with 170 kg body weight. Sperm were deep frozen in 5 ml maxi-straws with lactose-egg yolk and N-acetyl-D-glucosamine (LEN) diluent and stored in liquid nitrogen. Blood samples were obtained at 10 a.m. by inserting a 21 gauge, hypodermic needle attached to 10 ml syringe into surface veins in the ear. The concentration of testosterone was determined by Competitive Enzyme Immunoassay. Ovaries were collected from prepubertal gilts at a local slaughter house. Cumulus oocyte complexes were aspirated from antral follicles (3 to 6 mm in diameter). The medium used for oocyte maturation was modified TCM 199. After about 22 h of culture, oocytes were cultured without cysteamine and hormones for 22 h at $38.5^{\circ}C$, 5% $CO_2$ in air. For IVF, one frozen 5 ml straw was thawed at $52^{\circ}C$in 40 sec and was diluted with 20 ml Beltsville thawing solution at room temperature. Sperm were washed 2 times in mTLP-PVA and inseminated without preincubation after thawing. Oocytes were inseminated with $2{\times}10^7$/ml sperm concentration. Oocytes were coincubated for 6 h in 500 ${\mu}$l mTBM fertilization medium. At 6 h after IVF, oocytes were transferred into 500 ${\mu}$l NCSU-23 culture medium for further culture of 48 and 144 h. There were no significant differences in the semen volume, motility, normal acrosome morphology and sperm concentration of raw semen between A and B of Yorkshire boar. However, motility and normal acrosome of boar A were higher than those of boar B at 0.5, 2, 3, 4, 5 and 6 h incubations of frozen-thawed sperm. Testosterone concentration (3.75 ng/ml) of boar A was higher than that (2.34 ng/ml) of boar B. The rate of blastocyst formation (15.1%) of boar A was higher than that (10.4%) of boar B. In conclusion, serum testosterone concentration of boar showed very important role for the frozen-thawed sperm viability and the blastocyst formation of pig oocytes matured in vitro.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.117-117
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• 1992

Pubilc utility industries including the electric utility industry are facing a new stream of privatization com-petition with the private sector and deregulation. The necewssity to solve now and in the future power supply and demand problems has been increasing through the sophisticated generation expansion plan(GEP) approach con-sidering not only KEPCo's supply-side resources but also outside resources such as non-utility generation(NUG) demand-side management (DSM). Under the environmental situation in the current electric utility industry a new approach is needed to acquire multiple resources competitively. This study presents the development of a modified electric generation expansion analysis system(EGEAS) model with avoided cost based on the existing EGEAS model which is a dynamic program to develope an optimal generation expansion plan for the electric utility. We are trying to find optimal GEP in Korea's case using our modified model and observe the difference for the level of reliabilities such as the reserve margin(RM) loss of load probability(LOLP) and expected unserved energy percent(EUEP) between the existing EGEAS model and our model. In addition we are trying to calculate avoided cost for NUG resources which is a criterion to evaluate herem and test possibility of connection calculation of avoided cost with GEP implementation using our modified model. The results of our case study are as follows. First we were able to find that the generation expansion plan and reliability measures were largely influenced by capacity size and loading status of NUG resources, Second we were able to find that avoided cost which are criteria to evaluate NUG resources could be calculated by using our modified EGEAS model with avoided cost. We also note that avoided costs were calculated by our model in connection with generation expansion plans.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1542-1548
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• 2001

Wheat straw was treated on laboratory scale with 4% urea at a moisture level of 50% along with different amount of HC1 to fix various levels of ammonia (30, 40, 50 and 60%) and stored for 4 weeks. Result, revealed a significant (p<0.01) increase in CP content of the samples where HC1 was added. The CP content of the straw was only 7.8%, which increased to 14.1, 16.0, 15.0 and 15.2% with the addition of acid. Similarly the concentrations of NDF, ADF and hemicellulose was significantly different due to HC1 addition. The level of HC1 recommended was to trap 30% ammonia as there was not significant difference in CP content of straw due to addition of 4 levels of acids. Results of in vivo experiment conducted on nine buffaloes divided randomly into three groups of three animals in each revealed no significant difference in the intake of DM, OM, NDF, ADF, cellulose and hemicellulose in group I (ammoniated straw), group II (HC1 treated ammoniated straw) and group III (HC1 treated ammoniated straw + 1 kg barley grain), but the intake of CP was significantly (p<0.01) more in group III as compared to other 2 groups. The digestibility of DM, OM and CP was significantly (p<0.01) more in groups where HCI treated straw was fed as compared to only ammoniated straw fed group, whereas there was no significant difference in the digestibility of NDF, ADF and cellulose in 3 groups. Intake was significantly higher of nitrogen (p<0.05), calcium (p<0.01) and phosphorus (p<0.01) in group III as compared to other two groups. Animals in all the 3 groups showed positive nitrogen, calcium and phosphorus balance, though the balances of all the 3 nutrients were significantly higher in group III as compared to other 2 groups. Rumen fermentation study conducted in 3 rumen fistulated buffaloes in $3{\times}3$ latin square design offering the same 3 diets as in group I to III revealed that rumen pH was alike statistically in 3 groups and at various time intervals. The mean ammonia-N concentration was significantly (p<0.01) more in group II and III as compared to group I. The mean TVFA concentration (mM/100 ml SRL) were 6.46, 7.84 and 8.47 in 3 groups respectively and different statistically (p<0.01). Results revealed no significant difference in the activities of carboxy methyl cellulase, urease or protease at both the time of sampling (0 h and 4 h) in all the 3 groups of animals.

• The korean journal of orthodontics
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• v.41 no.6
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• pp.423-430
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• 2011

Objective: To evaluate the extent and aspect of stress to the cortical bone after application of a lateral force to a two-component orthodontic mini-implant (OMI, mini-implant) by using three-dimensional finite element analysis (FEA). Methods: The 3D-finite element models consisted of the maxilla, maxillary first molars, second premolars, and OMIs. The screw part of the OMI had a diameter of 1.8 mm and length of 8.5 mm and was placed between the roots of the upper second premolar and the first molar. The cortical bone thickness was set to 1 mm. The head part of the OMI was available in 3 sizes: 1 mm, 2 mm, and 3 mm. After a 2 N lateral force was applied to the center of the head part, the stress distribution and magnitude were analyzed using FEA. Results: When the head part of the OMI was friction fitted (tapped into place) into the inserted screw part, the stress was uniformly distributed over the surface where the head part was inserted. The extent of the minimum principal stress suggested that the length of the head part was proportionate with the amount of stress to the cortical bone; the stress varied between 10.84 and 15.33 MPa. Conclusions: These results suggest that the stress level at the cortical bone around the OMI does not have a detrimental influence on physiologic bone remodeling.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1722-1727
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• 2006

The nutritive value of 4 straws, obtained after thrashing of seeds from fodder crops, was assessed as complete feed for ruminants. Sixteen male Murrah buffaloes (liveweight 365.8${\pm}$19.5 kg), were divided into 4 equal groups and offered ad lib. straw of either Trifolium resupinatum, Trifolium alexandrium, Medicago sativa or Lolium perenne, supplemented with minerals and vitamin A, for 40 days in a completely randomized design. Simultaneously, each straw was offered to 3 rumen fistulated male buffaloes in order to assess the biochemical changes in the rumen. Compared to other straws M. sativa straw had higher (p<0.05) organic matter (OM), crude protein (CP), acid-detergent fiber (ADF) and cellulose content. L .perenne had the highest (p<0.05) hemicellulose and lowest (p<0.05) CP and acid-detergent lignin (ADL) content. T. resupinatum had the lowest concentration of cell wall constituents (CWC). The digestibility of nutrients of T. resupinatum and L. perenne straw was similar, but higher (p<0.05) than that of other straws. M.sativa straw showed highest (p<0.05) digestibility of CP. The highest OM digestibility of T. resupinatum and CP digestibility of M. sativa were responsible for highest (p<0.05) total volatile fatty acids and trichloroacetic acid precipitable nitrogen in the strained rumen liquor. The digestible crude protein (DCP) was highest (p<0.05) in M. sativa followed by that in T. alexandrium. The total purine derivatives excreted in urine varied from 0.22-0.32 mmol/kg $W^{.75}/d$. The efficiency of microbial protein synthesis indicated that OM of straws of M. sativa and that of T. alexandrium was used more (p<0.05) efficiently. The microbial protein synthesized was highest in T. resupinatum, but statistically similar to other groups. The values for N-retention and apparent biological value were highest for L. perenne, though comparable with that of M. sativa and T. alexandrium. The available metabolizable energy (ME) was highest (p<0.05) in T. resupinatum followed by that in L. perenne and lowest in M. sativa. It was concluded that all the straws, supplemented with minerals and vitamin A, could be fed exclusively to adult ruminants with no adverse affect, as animals were able to maintain body weight (372${\pm}$20.1 kg).

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.463-472
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• 2003

This experiment was carried out to investigate the effect of fermented chitosan additive(FCA) as a probiotics in finishing pig. The levels of 0.2% and 0.5% of FCA powder was added to the regular feed. A total of 30 pigs were used to evaluate the growing performance. Those FCA supplemented feeds were supplied to the pigs at 17 weeks of age for 6 weeks. After slaughtering, 4 pigs of each treatment were used to compare the physico-chemical characteristics and sensory evaluation. Addition of 0.2% of FCA improved the average daily weight gain and feed efficiency. The pH of the FCA treated loin was slightly higher than control. The L*, a*, b* values of the treatment groups were generally low compared to control group. So the effect of FCA to meat color was expression of purplish red color. Juiciness of the pork shoulder treated with 0.5% FCA was significantly(p<0.05) higher than the other groups. Flavor and overall preference scores for bacon treated with 0.5% of FCA were significantly(p<0.05) higher than the other groups.

• The Journal of Internal Korean Medicine
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• v.29 no.1
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• pp.117-129
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• 2008

Background & Objective : Naeso-san(NSS) has been used for the treatment of functional dyspepsia, regarded as a gastric dysmotility disease. A main cause of gastric dysmotility is antral dilatation or antroduodenal uncoordination. Therefore, we investigated the effect of NSS on gastric motility and its mechanism of action, as well as the morphologic changes in antral dilatated rats. Methods : Antral dilatated rats were induced by wrapping a nonabsorbable rubber ring(D:6mm, W:4mm, T:1mm) around the 1st portion of the duodenum for 8 weeks. Then morphologic changes were investigated and compared with normal intact rats before and after 8 weeks. Gastric emptying was measured by administration of normal saline(NS) or NSS in normal intact and antral dilatated rats. In another series of experiments to evaluate the mechanism of NSS under delayed conditions, normal intact rats were treated with atropine sulfate(1mg/kg, s.c.), quinpirole HCl(0.3mg/kg, i.p.), $NAME(N^{G}-nitro-L-arginine$ methyl ester, 75mg/kg, s.c.) and cisplatin(10mg/kg, i.p.), respectively. The myoelectrical activity of the gastric smooth muscle was recorded in normal intact and antral dilatated rats. The contractile waves were measured for 30 minutes before and after administration of each solution(NS, NSS). Results : Body weight gain of antral dilatated rats was significantly lower than that of the controls. Futhermore, we found the thickness of the mucosal and muscular layers and surface area of the stomach increased significantly compared with controls. NSS 278㎎/㎏ improved gastric emptying more than normal saline or NSS 93mg/kg in normal intact(p=0.026) and antral dilatated rats(p=0.03). NSS enhanced gastric emptying significantly in the NAME treated group(p=0.002). NSS 278mg/kg increased the significant postprandial dominant power than that of NS in normal intact rats, whereas there was no statistical significance in antral dilatated rats. Conclusions : NSS stimulates gastric motility through the cholinergic pathway. We expect that pathologic model with antral dilatation can be used as an exprimental tool which is similar to dyspepsia and NSS would be effective especially in dysmotility-like functional dyspepsia with antral dilatation or impaired reservoir functions such as gastric adaptive relaxation.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.120-120
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• 1998

Boron nitride (BN) films have attracted a growing interest for a variety of t technological applications due to their excellent characteristics, namely hardness, c chemical inertness, and dielectrical behavior, etc. There are two crystalline phases 1551; of BN that are analogous to phases of carbon. Hexagonal boron nitride (h-BN) has a a layered s$\sigma$ucture which is spz-bonded structure similar to that of graphite, and is t the stable ordered phase at ambient conditions. Cubic boron nitride (c-BN) has a z zinc blende structure with sp3-bonding like as diamond, 따ld is the metastable phase a at ambient conditions. Among of their prototypes, especially 삼Ie c-BN is an i interesting material because it has almost the same hardness and thermal c conductivity as di없nond. C Conventionally, significant progress has been made in the experimental t techniques for synthesizing BN films using various of the physical vapor deposition 밍ld chemical vapor deposition. But, the major disadvantage of c-BN films is that t they are much more difficult to synthesize than h-BN films due to its narrow s stability phase region, high compression stress, and problem of nitrogen source c control. Recent studies of the metalorganic chemical vapor deposition (MOCVD) of I III - V compound have established that a molecular level understanding of the d deposition process is mandatory in controlling the selectivity parameters. This led t to the concept of using a single source organometallic precursor, having the c constituent elements in stoichiometric ratio, for MOCVD growth of 삼Ie required b binary compound. I In this study, therefore, we have been carried out the growth of h-BN thin f films on silicon substrates using a single source precursors. Polycrystalline h-BN t thin films were deposited on silicon in the temperature range of $\alpha$)() - 900 $^{\circ}$C from t the organometallic precursors of Boron-Triethylamine complex, (CZHs)3N:BRJ, and T Tris(dimethylamino)Borane, [CH3}zNhB, by supersonic molecular jet and remote p plasma assisted MOCVD. Hydrogen was used as carrier gas, and additional nitrogen w was supplied by either aDlIDonia through a nozzle, or nitrogen via a remote plasma. T The as-grown films were characterized by Fourier transform infrared spectroscopy, x x-ray pthotoelectron spectroscopy, Auger electron spectroscopy, x-ray diffraction, t transmission electron diffraction, optical transmission, and atomic force microscopy.roscopy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.4
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• pp.325-338
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• 2016

Properties of aggregation and spatial distribution of fish were examined based on three lines in the South Sea of Korea using three frequencies (18, 38, and 120 kHz) of a scientific echosounder. The vertical distribution of fish was displayed using acoustic biomass namely nautical area scattering coefficient (NASC). As a result, at 120 kHz high NASC showed from water surface to 20 meters in deep while at 18 and 38 kHz very high NASC presented in 70 ~ 90 meters in depth, especially at line 3. Among three lines, the line 2 had lowest NASC. The horizontal distribution of fish using three frequencies together exhibited high NASC between the eastern South Sea and center of South Sea. In especial, NASC ($801{\sim}1,920m^2/n{\cdot}mile^2$) was observed along coastal waters from Busan to Tongyeong, Geoje, and Namhae. In regard with the property of aggregation of fish schools, the volume back-scattering strength ($S_V$) of three lines presented close each other, however, the range of $S_V$ in the line 2 was shortest (-53.5 ~ -43.4 dB). The average distributional depth was deep in the order of L3 ($32.8{\pm}9.0m$), L1 ($45.2{\pm}9.5m$), L2 ($49.7{\pm}5.6m$). The average altitude was high in the order of L3 ($13.4{\pm}10.3m$), L1 ($17.0{\pm}12.6m$), L2 ($56.7{\pm}5.6m$). The average length, thickness, and area were large in the order of L1, L3, and L2. This means that small sized fish schools were distributed near water surface in the line 2 while relatively large and similar sized fish aggregations between line 1 and line 3 appeared however, fish schools at line 3 had lower distributional depth and smaller compared to those at line 1. Acoustic data were visualized for demonstrating the entire circumstances of survey area. Additionally, there was no correlation between acoustic and trawl results.

• Applied Chemistry for Engineering
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• v.23 no.4
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• pp.372-376
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• 2012

Carbon nanotubes (CNT) are considered as one of ideal nano-fillers in the field of composites with their excellent electrical, mechanical, and thermal properties. Therefore CNT composites are increasingly used in fabricating conductive materials, structural materials with high strength and low weight, and multifunctional materials. The main problem of the CNT composites is difficulty in the dispersion of CNT in the polymer matrix. In this study multi-walled carbon nanotubes (MWNT) were pretreated by the physical process utilizing a wrapping method. After the pretreatment polymer/MWNT nanocomposites were prepared by melt processing. The effect of functionalization MWNT by wrapping with styrene acrylonitrile (SAN) on the mechanical and electrical properties of acrylonitrile butadiene styrene resin (ABS)/MWNT composites was studied by comparing the properties of ABS mixed with the neat MWNT. Electrical and mechanical properties of ABS/MWNT nanocomposites were studied as a function of the functionalization and content of MWNT. The tensile strength of the ABS/MWNT nanocomposites increased, but the impact strength decreased. The polymer wrapping in ABS system has little effect on the improvement of electrical properties.