• Korean Journal of Acupuncture
• /
• 제22권4호
• /
• pp.83-90
• /
• 2005

Objectives : To investigate the effects of acupuncture at Gansoo (B-18) and Chungwan (CV-12) on lipid metabolism in rats fed peroxidized lipid diet. Methods : Effects of acupuncture at Gansoo and Chungwan on plasma and liver lipid composition and antioxidative capacity were investigated in rats fed peroxidized lipids. Results : Although the level of plasma total cholesterol and triglyceride showed a tendency to decrease in the acupuncture group, the plasma HDL-cholesterol concentration showed no significant difference. The level of liver total cholesterol and triglyceride showed no significant difference in all treatment groups. Thiobarbituric acid( TBARS ) values in plasma and liver showed a tendency to decrease in the acupuncture groups. The plasma GOT and GPT activities showed low values in the acupuncture groups. The liver glutathione peroxidase, superoxide dismutase and catalase activity showed high values in the acupuncture groups. Conclusions : The results suggest that acupuncture at Gansoo (B-18) and Chungwan (CV-12) may have an influence on lipid metabolism via enhancing antioxidative capacity.

• Journal of Welding and Joining
• /
• 제25권4호
• /
• pp.42-48
• /
• 2007

An inert gas atomized NiTiZrSiSn bulk metallic glass feedstock was sprayed onto the copper plate using vacuum plasma spraying process. In order to change the in-flight particle energy, that is, thermal energy, the hydrogen gas flow rate in plasma gas mixture was increased at the constant flow rate of argon gas. Coating and single pass spraying bead were produced with the least feeding rate. Regardless of the plasma gas composition, fully melted through unmelted particle could be observed on the overlay coating. However, the frequency of the unmelted particle number density was increased with the decrease of the hydrogen gas flow rate. The amorphous phase fraction within coating was also affected by the number density of the unmelted particle.

• Journal of Nutrition and Health
• /
• 제27권2호
• /
• pp.109-117
• /
• 1994

This study was conducted to evaluate dietary fat intake and its effect on the plasma lipids and fatty acids composition in plasma and red blood cells(RBC) in 96 healthy Korean female college student. Three-day food intakes were recorded, and fasting blood samples were collected and analyzed for plasma total cholesterol and triglyceride. Fatty acid compositions were determined in plasma and RBC membrane. Oleic acid was the most abundant in diet, followed by palmitic and linoleic acids. Mean daily intake of cholesterol was 219$\pm$127mg, mean plasma cholesterol was 160$\pm$24mg/이 and mean plasma triglyceride was 68$\pm$25mg/dl. Plasma fatty acids were mostly composed of linoleic, palmitic and oleic acids, while palmitic, stearic and arachidonic acids were high in RBC membrane. Plasma triglyceride showed positive correlation with BMI. Among dietary fatty acids, arachidonic acid, EPA and DHA showed negative correlation with plasma total cholesterol. Plasma triglyceride levels were negatively correlated with dietary arachidonic acid, plasma n-6 fatty acids and plasma polyunsaturated fatty acids. Dietary EPA and DHA levels were positively correlated with plasma EPA, dietary n-3/n-6 ratio were positively correlated with plasma n-3 fatty acids and n-3/n-6 ratio. Highly significant correlations were shown between the levels in plasma and RBC for several fatty acids.

• 한국재료학회지
• /
• 제9권5호
• /
• pp.496-502
• /
• 1999

In this study, n-GaN samples were etched using planar inductively coupled $Cl_2$/$H_2$plasmas and the effects of plasma conditions on the etch properties, surface composition, and ohmic contact formation were investigated as a function of gas combination. As the addition of hydrogen to the $Cl_2$plasma increased to 100%, GaN etch rates decreased due to the reduction of chlorine radical density. Even though the variation of the surface composition is limited under $50\AA$, the surface composition was also changed from Ga-rich to N-rich with the increased addition of hydrogen to $Cl_2$. Etch products by the reaction between Ga in GaN and Cl in $Cl_2$ plasma were investigated using OES analysis during the GaN etching. The value of specific resistivity of the contact formed on the n-GaN etched using 100% $Cl_2$plasma was 3.1$\times$10\ulcorner$\Omega$$\textrm{cm}^2$, and which was lower than that formed on the non-etched n-GaN. However, the resistively was increased with the increased hydrogen percent in $Cl_2$/$H_2$.

• 대한금속재료학회지
• /
• 제47권11호
• /
• pp.716-721
• /
• 2009

The major drive for the application of low-temperature plasma treatment in nitrocarburizing of austenitic stainless steels lies in improved surface hardness without degraded corrosion resistance. The low-temperature plasma nitrocarburizing was performed in a gas mixture of $N_{2}$, $H_{2}$, and carbon-containing gas such as $CH_{4}$ at $450^{\circ}C$. The influence of the processing time (5~30 h) and $N_{2}$ gas composition (15~35%) on the surface properties of the nitrocarburized layer was investigated. The resultant nitrocarburized layer was a dual-layer structure, which was comprised of a N-enriched layer (${\gamma}_N$) with a high nitrogen content on top of a C-enriched layer (${\gamma}_C$) with a high carbon content, leading to a significant increase in surface hardness. The surface hardness reached up to about $1050HV_{0.01}$, which is about 4 times higher than that of the untreated sample ($250HV_{0.01}$). The thickness of the hardened layer increased with increasing treatment time and $N_{2}$ gas level in the atmosphere and reached up to about $25{\mu}m$. In addition, the corrosion resistance of the treated samples without containing $Cr_{2}N$ precipitates was enhanced than that of the untreated samples due to a high concentration of N on the surface. However, longer treatment time (25% $N_{2}$, 30 h) and higher $N_{2}$ gas composition (35% $N_{2}$, 20 h) resulted in the formation of $Cr_{2}N$ precipitates in the N-enriched layer, which caused the degradation of corrosion resistance.

• 한국진공학회지
• /
• 제8권4A호
• /
• pp.438-444
• /
• 1999

The characterization of the reactively sputtered ITO layer on the PET film has been studied. The PEM device has been used to determine the optimum stoichimetry through control of the amount of oxygen incorporated into the alloy target and the optimum operation conditions to produce films with the highest electrical conductivity and visible transparency. The PEP film was pre-treated under the plasma discharge condition to remove the adsorbed gases and to modify the surface morphology. The results revealed that by adjusting the flow rate of oxygen with the spectral intensity of indium target, the composition of plasma gas can be kept constant during the entire deposition period. The resistivity of ITO film obtained was fond to be about 37$\Omega\Box$, and the transmittance of visual range was about 86%.

• Corrosion Science and Technology
• /
• 제8권6호
• /
• pp.227-231
• /
• 2009

Mg and Mg alloys have been used for lots of applications, including automobile industry, aerospace, mobile phone and computer parts owing to low density. However, Mg and Mg alloys have a restricted application because of poor corrosion properties. Thus, improved surface treatments are required to produce protective films that protect the substrate from corrosive environments. Environmental friendly Plasma Electrolytic Oxidation (PEO) has been widely investigated on magnesium alloys. PEO process combines electrochemical oxidation with plasma treatment in the aqueous solution. In this study, AZ91 Mg alloys were treated by PEO process in controlling the current with PC condition and treated time, concentration of NaF, NaOH, and $Na_2SiO_3$. The surface morphology and phase composition were analyzed using SEM, EDS and XRD. The potentiodynamic polarization tests were carried out for the analysis of corrosion properties of specimen. Additionally, salt spray tests were carried out to examine and compare the corrosion properties of the PEO treated Mg alloys.

• Nuclear Engineering and Technology
• /
• 제52권6호
• /
• pp.1148-1155
• /
• 2020

This work presents two different methods for quantifying and propagating the uncertainty associated with fuel composition at end of life for cask criticality calculations. The first approach, the computational approach uses parametric uncertainty including those associated with nuclear data, fuel geometry, material composition, and plant operation to perform forward depletion on Monte-Carlo sampled inputs. These uncertainties are based on experimental and prior experience in criticality safety. The second approach, the data-driven approach relies on using radiochemcial assay data to derive code bias information. The code bias data is used to perturb the isotopic inventory in the data-driven approach. For both approaches, the uncertainty in k_eff for the cask is propagated by performing forward criticality calculations on sampled inputs using the distributions obtained from each approach. It is found that the data driven approach yielded a higher uncertainty than the computational approach by about 500 pcm. An exploration is also done to see if considering correlation between isotopes at end of life affects k_eff uncertainty, and the results demonstrate an effect of about 100 pcm.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
• /
• pp.194-195
• /
• 2005

(100-x)Zn xMg alloy films are prepared onto cold-rolled steel substrates; where x ranged from 0 to about 38 atomic %. The alloy films show microcrystalline and grain structures respectively, according to preparation conditions such as composition ratio of zinc and magnesium or gas pressures etc.. And X-ray diffraction analysis indicates not only the presence of Zn-Mg thin films with forced solid solution but also the one of $MgZn_2$ alloy films partly. In addition the influence of Mg/Zn composition ratio and morphology of the Zn-Mg alloy films on corrosion behavior is evaluated by electro-chemical anodic polarization tests in deaerated 3% NaCl solution. From this experimental results, all the prepared Zn-Mg alloy films showed obviously good corrosion resistance to compare with 99.99% Zn and 99.99% Mg Ingots for evaporation metal. It is thought that the Zn-Mg films with effective forced solid solution prepared by plasma enhanced PVD method, produces smaller and denser grain structure so that may improve the formation of homogeneous passive layer in corrosion environment.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권8호
• /
• pp.1105-1109
• /
• 2005

The effect of dietary fatty acid supplementation on milk production, milk composition and plasma constituents in dairy cows was examined. Dietary fatty acids including mainly palmitic acid and stearic acid were given to cows from 2 weeks before and 8 weeks after parturition. Weekly gain of daily milk production was increased gradually during early lactation period and reached a plateau at 4 weeks after parturition. Weekly gain of daily milk production in lactating cows received dietary fatty acids was significantly higher than that of cows given a control diet alone. Although milk lactose concentration was slightly decreased by dietary fatty acid supplementation, milk fat and protein were not significantly influenced by dietary fatty acid supplementation. Dietary fatty acids did not affect plasma concentrations of triglyceride, non-esterified fatty acids, total cholesterol, high-density lipoprotein cholesterol and glucose during postpartum. It is suggested that dietary fatty acid supplementation has the potency to enhance energy balance and improve milk yield without any adverse effects on milk composition.