• Toxicological Research
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• v.21 no.2
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• pp.141-150
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• 2005

1,3-Dichloro-2-propanol (1,3-DCP) is known as chloride chemicals and causes severe hepatotoxic agent. The Ito cells and Kupffer's cells of the liver in the 5 old F344 Rats were exposed to 1,3-DCP gas chamber for 6 hours/ a day, 5 days/ a week, and 13 weeks, in the 0, 5, 20, 80 ppm, respectively. After then the body weights, liver weights, and relative liver weight to body weight were measured, and the hepatic tissues were prepared by the routine and Immunostain method, and observed by the LM, and EM. In the results, there were severe body weight decrease (p<0.05) in the 80 ppm of the male and female rats. The relative liver weights to the body weight were increased relate with exposed 1,3-DCP concentration (P<0.001). Inflammatory cells, infiltration was observed at the perivascular area in the 20 ppm exposed group, and bilirubin pigment infiltration, bile duct hyperplasia, inflammation hepatocytic necrosis, fibrosis were observed in the 80 ppm exposure group. In the 80 ppm exposure group, disarrangement of the endothelial cells, erythrocytes and hepatic cell fragment in the Disse space and numerous migration macrophages were observed in the necrotic area by EM observation. In the immunostained hepatic tissues positive stained ED1 cells were extremely increased (P<0.05) in central vein area, but ED2 was weakly positive immunostained in the 80 ppm exposed group. Immunostained desmin was observed in the Ito cell. It was no difference in the low and medium exposed group but it was typical increase in the necrotic area. In conclusion, These results suggest that NOAEL of 1,3-DCP may be 5 ppm in rats and the Immunostained of desmin, ED1 and ED2 positive cells activated in the inflammatory liver were related to the exposure volume and density. The increase of the Ito cells were related to the severe phagocytosis of the Kupffer's cells.

• Clean Technology
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• v.9 no.4
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• pp.169-177
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• 2003

In order to develope a clean technology by liquid-supported membrane of ionic liquid/PVDF, the solubility of R22 and HFP gases using BMIBF4 as ionic liquid were measured at temperatures from 0 to $30^{\circ}C$, at total pressures up to 4 bars. The solubility of R22 in this ionic liquid was shown a rapid increasing tendency with increases of pressure and decreases of temperature, respectively, whereas the solubility of HFP was showed only a little in the same conditions. Based on these results, liquid-supported membranes of ionic liquid/PVDF were prepared by variables of the deposition amount of ionic liquid in polymer matrix, PVDF and were applied to the separation of fluoro-gases(R22, HFP) including $N_2$ gas. The permeability of R22 was rapidly increased by depending on the deposition amounts of ionic liquid, whereas both of HFP and $N_2$ were just showed so little. Especially, the diffusivity coefficient and solubility parameter of R22 were increased by lower operating temperatures and increased deposition amount of ionic liquid in 1iquid membrane. In conclusion, the selectivity of R22 against HFP was changed to 10-45 times depending on both of operating temperatures and the deposition amount of ionic liquid in BMIBF4/PVDF liquid membrane.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.829-834
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• 1998

Concerned with environmental issue, a new decomposition method for CFCs that caused the destruction of ozone layer was proposed. Using thermal plasma process, CFC113 decomposed completely. In order to quantify the tendency in decomposition and recombination of CFC113, thermodynamic equilibrium calculations were performed. The calculation was conducted with CFC113, $H_2$, $O_2$ at 1 atm and 300 K~5000 K. In the experiment, products which are generated after decomposition in the plasma were examined by varying reacting gases($H_2$, $O_2$) flow rates and the changes of inside diameters of quenching tubes. Decomposition products were analyzed using Gas Chromatograph. The results are very promising with a decomposition efficiency greater than 99.99%. As to CFC113/$H_2$=1/3, conversion to CO decreased with increasing $O_2$ ratio. When CFC113/$O_2$=1/1, 1/1.5 and 1/2, conversion to CO increases above $H_2$ ratio of 3. The change of CO conversion is not sensitive to power changes. As total flow rate increased, CO conversion was slightly decreased. When the inside diameter of the quenching tube was changed from 8mm into 4mm, CO conversion was increased due to enhanced quenching rate.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.203-209
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• 2007

In order to promote utilization of the Yangha (Zinger mioga Rosc.) as functional food and natural spices, and 95.93%, from the dried one 7.63%, and from powder 9.81%, respectively. Crude protein content from the Yangha powder was 11.21%, and contents of crude fat, crude ash and crude fiber were 2.44%,10.78%, and 14.47%, respectively. Most of compositions from Yangha powder were higher than those from raw and the dried one, except fer water content. Antioxidative effect was investigated through Rancimat and DPPH methods. Oxidative stability of Yangha powder was the highest of4.21Al. Furthermore, the free radical scavenging activity of Yangha powder (76.61%) was higher than that of raw (49.35%) or the dried one (61.78%). Volatile flavor compounds of Yangha was extracted by steam distillation and extraction method. The extracts were analyzed and identified by gas chromatography and GC-MS spectrometry. One hundred twenty two volatile flavor components were identified, and the major component was terpene compounds including ${\alpha}$-pinene, ${\beta}$-pinene, ${\beta}$-phellandrene, 1,4-terpineol, and ${\beta}$-terpinene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1689-1697
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• 2004

Aroma compounds in 6 different Byeolmijang were extracted by SDE (simultaneous steam distillation extraction) and analyzed with GC (gas chromatography) and GC/MS (mass-spectrometry). The major aroma compounds in the 6 different Byeolmijang during aging were 1-octene-3-ol, hexanal, benzeneacetaldehyde, benzaldehyde, furfural, pyrazine compounds, benzyl-alcohol, furan compounds and phenol type compounds. Generally, benzeneacetaldehyde, benzaldehyde, furfural, pyrazine compounds and phenol type compounds were increased during aging. On the other hand, 1-octene-3-ol, hexanal, benzyl-alcohol and furan compounds were decreased during aging. 2-Heptenal and 2,4-decadienal in Daemaekjang, pyrazine and phenol type compounds in Sanghwangjang and phenol type compounds including phenol, 4-methoxy-phenol and 4-ethyl-phenol in Mujang were identified as major aroma compounds, respectively. The major aroma compound in Bizijang was 2,4-decadienal and in Sodujang, the major aroma compounds were 2,3-dihydro-benzofuran and 2-methoxy-4-vinylphenol. Linaool, geraniol, 6-elemene, 6-lonone and ledene were detected in Jigeumjang possibly due to the addition of powdered red pepper.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.363-363
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• 2008

The development of dry etching process for sapphire wafer with plasma has been key issues for the opto-electric devices. The challenges are increasing control and obtaining low plasma induced-damage because an unwanted scattering of radiation is caused by the spatial disorder of pattern and variation of surface roughness. The plasma-induced damages during plasma etching process can be classified as impurity contamination of residual etch products or bonding disruption in lattice due to charged particle bombardment. Therefor, fine pattern technology with low damaged etching process and high etch rate are urgently needed. Until now, there are a lot of reports on the etching of sapphire wafer with using $Cl_2$/Ar, $BCl_3$/Ar, HBr/Ar and so on [1]. However, the etch behavior of sapphire wafer have investigated with variation of only one parameter while other parameters are fixed. In this study, we investigated the effect of pressure and other parameters on the etch rate and the selectivity. We selected $BCl_3$ as an etch ant because $BCl_3$ plasmas are widely used in etching process of oxide materials. In plasma, the $BCl_3$ molecule can be dissociated into B radical, $B^+$ ion, Cl radical and $Cl^+$ ion. However, the $BCl_3$ molecule can be dissociated into B radical or $B^+$ ion easier than Cl radical or $Cl^+$ ion. First, we evaluated the etch behaviors of sapphire wafer in $BCl_3$/additive gases (Ar, $N_2,Cl_2$) gases. The behavior of etch rate of sapphire substrate was monitored as a function of additive gas ratio to $BCl_3$ based plasma, total flow rate, r.f. power, d.c. bias under different pressures of 5 mTorr, 10 mTorr, 20 mTorr and 30 mTorr. The etch rates of sapphire wafer, $SiO_2$ and PR were measured with using alpha step surface profiler. In order to understand the changes of radicals, volume density of Cl, B radical and BCl molecule were investigated with optical emission spectroscopy (OES). The chemical states of $Al_2O_3$ thin films were studied with energy dispersive X-ray (EDX) and depth profile anlysis of auger electron spectroscopy (AES). The enhancement of sapphire substrate can be explained by the reactive ion etching mechanism with the competition of the formation of volatile $AlCl_3$, $Al_2Cl_6$ or $BOCl_3$ and the sputter effect by energetic ions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1179-1185
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• 2011

Cold and hot-rolled carbon steel sheets are commonly used in railroad cars or commercial vehicles such as the automobile. The sheets used in these applications are mainly fabricated by spot welding, which is a type of electric resistance welding. However, the fatigue strength of a spot-welded joint is lower than that of the base metal because of high stress concentration at the nugget edge of the spot-welded part. In particular, the fatigue strength of the joint is influenced by not only geometrical and mechanical factors but also the welding conditions for the spot-welded joint. Therefore, there is a need for establishing a reasonable criterion for a long-life design for spot-welded structures. In this thesis, ${\Delta}P-N_f$ relation curves have been used to determine a long-life fatigue-design criterion for thin-sheet structures. However, as these curves vary under the influence of welding conditions, mechanical conditions, geometrical factors, etc. It is very difficult to systematically determine a fatigue-design criterion on the basis of these curves. Therefore, in order to eliminate such problems, the welding residual stresses generated during welding and the stress distributions around the weld generated by external forces were numerically and experimentally analyzed on the basis of the results, reassessed fatigue strength of gas welded joints.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.517-522
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• 2013

The effect on methanogens attached to the surface of rumen ciliate protozoa by the addition of plant extracts (pine needles and ginkgo leaves) was studied with particular reference to their effectiveness for decreasing methane emission. The plant extracts (pine needles and ginkgo leaves) were added to an in vitro fermentation incubated with rumen fluid. The microbial population including bacteria, ciliated-associated methanogen, four different groups of methanogens and Fibrobacter succinogenes were quantified by using the real-time PCR. Gas profiles including methane, carbon dioxide and hydrogen, and runinal fermentation characteristics were observed in vitro. The methane emission from samples with an addition of individual juices from pine needles, ginkgo leaves and 70% ethanol extract from ginko leaves was significantly lower (p<0.05, 27.1, 28.1 and 28.1 vs 34.0 ml/g DM) than that of the control, respectively. Total VFAs in samples with an addition of any of the plant extracts were significantly lower than that of the control (p<0.05) as well. The order Methanococcales and the order Methanosarcinales were not detected by using PCR in any incubated mixtures. The ciliate-associated methanogens population decreased from 25% to 49% in the plant extacts as compared to control. We speculate that the supplementation of juice from pine needles and ginkgo leaves extract (70% ethanol extract) decreased the protozoa population resulting in a reduction of methane emission in the rumen and thus inhibiting methanogenesis. The order Methanobacteriales community was affected by addition of all plant extracts and decreased to less than the control, while the order Methanomicrobiales population showed an increase to more than that of the control. The F. succinogenes, the major fibrolytic microorganism, population in all added plant extracts was increased to greater than that of the control. In conclusion, pine needles and ginkgo leaves extracts appear to have properties that decrease methanogenesis by inhibiting protozoa species and may have a potential for use as additives for ruminants.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.573-579
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• 2010

This study was conducted to determine the effects of different copper (inorganic and organic) and energy (tallow and glycerol) sources on growth performance, nutrient digestibility, gas emission, diarrhea incidence, and fecal copper concentration in growing pigs by using a 2${\times}$2 factorial design. In this trial, 96 pigs (63 d of age) were employed, with an average initial weight of 28.36${\pm}$1.14 kg. The dietary treatments were i) basal diet with 134 ppm copper (Korea recommendation) as $CuSO_4$+tallow; ii) basal diet with 134 ppm Cu as $CuSO_4$+glycerol; iii) basal diet with 134 ppm copper as CuMet+tallow; and iv) basal diet with 134 ppm copper as CuMet+ glycerol. Throughout the entire experimental period, no differences were noted among treatment groups with regard to the magnitude of improvement in ADG (average daily gain), ADFI (average daily feed intake) and G/F (gain:feed) ratios. The nitrogen (N) digestibility of pigs fed on diets containing organic copper was improved as compared with that observed in pigs fed on diets containing inorganic copper (p<0.05). An interaction of copper${\times}$energy was observed in the context of both nitrogen (p<0.05) and energy (p<0.01) digestibility. Ammonia emissions were significantly lower in the organic copper-added treatment groups than in the inorganic copperadded treatment groups (p<0.05). Mercaptan and hydrogen sulfide emissions were reduced via the addition of glycerol (p<0.05). No significant effects of copper or energy source, or their interaction, were observed in reference to diarrhea appearance and incidence throughout the entirety of the experimental period. The copper concentration in the feces was significantly lower in the organic copper source treatment group than was observed in the inorganic copper source treatment group (p<0.05). The results of this experiment show that organic copper substituted for inorganic copper in the diet results in a decreased fecal copper excretion, but exerts no effect on performance. The different energy (tallow and glycerol) sources interact with different copper sources and thus influence nutrient digestibility. Glycerol supplementation may reduce the concentrations of odorous sulfuric compounds with different Cu sources.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.591-599
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• 1996

This study was undertaken to investigate the cytotoxicity of orthodontic wires after doing various treatments to the wires. 018x025 inch Stainless steel(A) and Co-Cr(B) wires were used and each of them were divided into 4 groups. A-1 and B-1 groups were as received state, and A-2 and B-2 groups were heat treated. A-3 and B-3 groups were electropolished after heat treatment, and A-4 and B-4 groups were soldered with Ag-solder. Each group had 3 wires and these were sterilized with Ethylene Oxide gas. We used human gingival fibroblast cell culture and agar overlay technique to investigate the cytotoxicity of each group of wires. The cytotoxicity of wire was assessed using reaction index (zone index/lysis index). The findings of this study were as follows. 1. Both of the stainless steel wire and Co-Cr wire showed no cytotoxicity in as received state. 2. Heat treatment or electropolishing of the wires had no effect on the cytotoxicity of the wires 3. Soldered stainless steel wires showed a little wider zone of discoloration than soldered Co-Cr wires, but the zone index and cytotoxicity(reaction index) was not different. 4. Soldered wires showed moderate cytotoxicity in both of the wires.