• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.6
• /
• pp.1051-1057
• /
• 2010

Database for the damage reference by armor piercing bullet test was established for both tube and plate specimens having a range of thickness. As the inclined angles of hit are increasing, it has been found that penetration damage diameter tends to increases accordingly in both specimen of the tube and plate, and such penetration damage diameter on the rear side becomes bigger than those on the front side. The tube specimen showed that the damage becomes bigger when central areas rather than the peripheral were hit. Through the plate test, it also has been found that the penetration ballistic limit for Al alloy is about 25.4mm and that of stainless steel about 12.7mm. From the fatigue analysis results using the database for damage reference, it has been identified whether the safety requirements of military aircraft could be met.

• Journal of Korean Institute of Industrial Engineers
• /
• v.7 no.1
• /
• pp.33-36
• /
• 1981

An equipment is subject to shocks which occur randomly according to a Poisson process. The equipment fails when the total cumulative damage reaches a certain prescribed level. An optimal preventive replacement policy is presented when the level of cumulative damage cannot be checked. Renewal theory is used to obtain the results and a case example is presented.

• Natural Product Sciences
• /
• v.12 no.1
• /
• pp.8-13
• /
• 2006

The present study was carried out to investigate the hepatoprotective effect of the extract of Pterocarpus santalinus Linn on acute hepatotoxicity induced in Wistar albino rats by a single dose of Galactosamine (400 mg/kg). Suspensions of methanolic extract of heartwood of P. santalinus (200 and 400 mg/kg) in 0.3% Carboxy Methyl Cellulose (CMC) were administered p.o. to experimental animals and hepatoprotective activity was monitored by estimating aspartate amino transferase (ASAT, GOT), alanine amino transferase (ALAT, GPT), alkaline phosphatase (ALP), total bilirubin (TB), lactate dehydrogenase (LDH), total cholesterol (TC), triglycerides (TGL), albumin, total protein (TP) levels. The methanolic extract significantly reduced the elevation of serum transaminases and alterations of biochemical parameters induced by hepatotoxin, and alleviated the degree of liver damage. The results were supported by histopathological studies of liver samples showing regeneration of hepatocytes in treated animals. Silymarin (25 mg/kg), a known hepatoprotective drug was used for comparison. Based on the results obtained, it can be concluded that P. santalinus exerts hepatoprotective activity and may serve as a useful adjuvant in several clinical conditions associated with liver damage.

• Environmental Analysis Health and Toxicology
• /
• v.15 no.4
• /
• pp.147-155
• /
• 2000

In order to evaluate anti -oxidant activities and protective effect against oxidatve damage, DPPH radical scavenging activity and lipid peroxidation inhibitory activity were measured among methanol extracts prepared from natural medicinal plants. Fourteen natural medicinal plants which were reported to have anti -oxidative or anti-inflammatory effects were selected based on our previous report. In addition to the total methanol extracts, n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions were prepared from each total extract. DPPH radical scavenging assay was performed against 14 total extracts and all samples showed dose-dependent activities in various extent. Among those, 6 samples, methanol extracts of Euryale ferox, paeonia suffruticosa, Areca catechu var. dulcissima, Cinnamomun cassia, Alpinia katsumadai and Betula platyphlla var. japonica showed IC$\sub$50/ value lower than 6.0 $\mu\textrm{g}$/ml. The highest DPPH radical scavenging activity was found in ethylacetate fraction of paeonia suffruticosa with IC$\sub$50/ value of 1.1 $\mu\textrm{g}$/ml. Analysis of lipid peroxidation inhibitory activity on hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast (V79-4) cells revealed that the highest inhibitory effect was observed in methanol extract of Betula platyhpylla var. japonica. Lipid peroxidation inhibitory activity was observed as a dose-dependent manner in all samples used in this study. Among fraction samples, ethylacetate fraction of Alpinia katsumadai had the strongest inhibitory activity with IC$\sub$50/ value of 0.9 $\mu\textrm{g}$/ml.

• International Journal of Oral Biology
• /
• v.33 no.4
• /
• pp.137-141
• /
• 2008

The present study reports the protective properties of a total methanol extract of B. platyphylla var. japonica against ultraviolet (UV)-C irradiation. Pretreatment of Chinese hamster fibroblast (V79-4) cells with a total methanol extract significantly increased cell survival following $300\;J/m^2$ of UV-C irradiation. The total methanol extract was further fractionated into 5 fractions: n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these fractions, B. platyphylla var. japonica ethylacetate, butanol and water fractions showed significant protective effects against the cellular damage induced by UV-C irradiation. In order to elucidate the mechanism underlying this protective effect, DPPH (Editor note: abbreviations should be spelled out at first use.) radical scavenging and lipid peroxidation inhibitory activity were measured. Significant radical scavenging and lipid peroxidation inhibitory activities were observed for the ethylacetate fraction. In summary, the present data demonstrate that an extract of B. platyphylla var. japonica has a significant protective effect against UV-C irradiation. The underlying mechanism of this protective effect may involve radical scavenging and inhibition of lipid peroxidation by the B. platyphylla var. japonica extract.

• Culinary science and hospitality research
• /
• v.12 no.2 s.29
• /
• pp.151-167
• /
• 2006

This study shows the differences among residents’ consciousness for general infectious disease and sterilization mediated by vermin. We categorized both industry-related people who work in restaurants, hygiene service shops, whole sales, government organizations, PC shops, factories, department stores and non-industry-related people who work in schools, general offices into two groups for this study. The discovery of vermin held 86% of total exam cases. The vermin included mosquitoes, cockroaches, ants, flies, and so on. People thought these vermin might mediate bacteria infection to human. 80.3% of persons thought mite might exist in blankets, beds and couches. Among 66.6% of total experience of vermin damage, the main damage came from mosquitoes. Frequently used methods of prevention from vermin damage were as follows: "spray of effective chemicals", "install traps" and " report to a prevention company" in order. It indicated that people did not take special actions to repel vermin in spite of their knowing seriousness of damage. Furthermore, just half cases were executed regular sanitization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.5
• /
• pp.507-511
• /
• 2024

Various process modifications have been used to minimize SiO₂ gate oxide aging in metal-oxide-semiconductor field-effect transistors (MOSFETs). In particular, post-metallization annealing (PMA) with a deuterium ambient can effectively eliminate both bulk traps and interface traps in the gate oxide. However, even with the use of PMA, it remains difficult to prevent high levels of radiation-induced gate oxide damage such as total ionizing dose (TID) during long-term missions. In this context, additional low-temperature heat treatment (LTHT) is proposed to recover from radiation-induced damage. Positive traps in the damaged gate oxide can be neutralized using LTHT, thereby prolonging device reliability in harsh radioactive environments.

• Journal of Nutrition and Health
• /
• v.37 no.4
• /
• pp.281-290
• /
• 2004

The purpose of this project was to evaluate whether daily fruit juice consumption could reduce the DNA damage in healthy subjects. The study was performed using 67 healthy volunteers (29 smokers, 38 nonsmokers) who were supple-mented with 480 m1 of grape juice for 8 weeks. Eight weeks of grape juice consumption did not change any anthropometric parameters. Lymphocyte DNA damage before the study was significantly greater (p<0.05) in smoker than nonsmoker, but, grape juice consumption significantly reduced DNA damage in both smoker (26%) and nonsmoker (I7%) to the level where there was no difference remained between the two groups after the intervention trial. This preventive effect of grape juice against DNA damage was not affected by sex of the subjects in non-smokers. Plasma $\alpha$-carotene, Iyco-pene and ${\gamma}$-totopherol was significantly increased after the trial in smokers, while erythrocyte catalase was significan-tly increased in both smokers and nonsmokers. Total radical-trapping antioxidant potential (TRAP) level in all subjects was significantly reduced after the intervention, while GSH-Px activity was increased only in nonsmokers. These results suggests that daily consumption of grape juice may protect DNA damage in peripheral lymphocytes, and supports the hypothesis that grape juice might exert their effect partially via a decrease in oxidative damage to DNA in humans partly by improving their antioxidative defense system.

• Wind and Structures
• /
• v.20 no.3
• /
• pp.389-404
• /
• 2015

In this study, residential building damage states observed from a post-tornado damage survey in Joplin after a 2011 EF 5 tornado were used to reconstruct the near-surface wind field. It was based on well-studied relationships between Degrees of Damage (DOD) of building and wind speeds in the Enhanced Fujita (EF) scale. A total of 4,166 one- or two-family residences (FR12) located in the study area were selected and their DODs were recorded. Then, the wind speeds were estimated with the EF scale. The peak wind speed profile estimated from damage of buildings was used to fit a translating analytical vortex model. Agreement between simulated peak wind speeds and observed damages confirms the feasibility of using post-tornado damage surveys for reconstructing the near-surface wind field. In addition to peak wind speeds, the model can create the time history of wind speed and direction at any given point, offering opportunity to better understand tornado parameters and wind field structures. Future work could extend the method to tornadoes of different characteristics and therefore improve model's generalizability.

• Nutrition Research and Practice
• /
• v.4 no.3
• /
• pp.183-190
• /
• 2010

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against $H_2O_2$-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against $H_2O_2$-induced cell damage in vitro.