• 한국전기전자재료학회논문지
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• 제19권10호
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• pp.889-893
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• 2006

Chemical mechanical polishing (CMP) achieves surface planrity through combined mechanical and chemical means. The role of slurry is very important in metal CMP. Slurry used in metal CMP normally consists of oxidizers, complexing agents, corrosion inhibitors and abrasives. This paper investigates the effects of citric acid as a complexing agent for Cu CMP with $H_2O_2$. In order to study chemical effects of citric acid, X-ray photoelectron spectroscopy (XPS) was peformed on Cu sample after etching test. XPS results reveal that CuO, $Cu(OH)_2$ layer decrease but $CU/CU_2O$ layer increase on Cu sample surface. To investigate nanomechanical properties of Cu sample surface, nanoindentation was performed on Cu sample. Results of nanoindentation indicate wear resistance of Cu surface decrease. According to decrease of wear resistance on Cu surface removal rate increases from $285\;{\AA}/min\;to\;8645\;{\AA}/min$ in Cu CMP.

• Toxicological Research
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• 제11권1호
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• pp.81-89
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• 1995

A teratogenicity study of KTC-1, a new semisynthetic rifamycin antituberculous drug, was conducted in Sprague-Dawley rats. Dosages of KTC-1 0, 7, 21, and 63 mg/kg/day were administered to darns orally gayage from day 7 to day 17 of gestation. Two-third of dams per group were subjected to cesarean section on day 21 of pregnancy for examination of their fetuses, and the remaining one-third of darns per group were allowed to deliver naturally for postnatal examination of their offspring. At 21 mg/kg/day, an increase in the skeletal variations of F1 fetuses and a decrease in the body weight of F1 offspring were seen. At 63 mg/kg/day, a loss in body weight was observed in darns. An increase in fetal death rate, a decrease in litter size and body weight, and an increase in the incidence of visceral malforrnations and skeletal variations were found in F1 fetuses. In particular, lumar rib occurred at an incidence of 31%. In addition, an increase in the dead newborns at birth and neonatal deaths during the lactation period, a loss in body weight, and a decrease in spleen weight were observed in F1 offspring. There were no signs of maternal toxicity or embryotoxicity at 7 mg/kg/day. The results suggest that the no-effect dose level(NOEL)for dams is 21 mg/kg/day, and NOELs for F1 fetuses and offspring are 7 mg/kg/day.

• Journal of Ecology and Environment
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• 제35권2호
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• pp.73-78
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• 2012

$Calotropis$ $procera$ L. is a perennial shrub distributed in saline areas of deserts of South Asia. Salt stress is a very challenging subject in arid and semi-arid areas. Germination stage is very sensitive and many plants do not germinate in saline soil. The objective of this study was identifying the salinity effect on seed germination of $Calotropis$ $procera$ L. The experimental design was a complete randomized block design with NaCl and $CaCl_2$ at five levels of isobar concentrations: 0.0, -0.01, -0.05, -0.1, and -0.15 MPa. Osmotic potential had significant effects ($P$ < 0.01) on germination percentage, germination rate, shoot length, root length, and seedling dry weight. All seedling characteristics decreased with decrease in osmotic potential. Shoot length and root length decreased more than the seedling characteristics. Germination was completely inhibited in -0.1 Mpa. Priming with NaCl and $CaCl_2$ (-0.1 MPa) for four days had significant effects ($P$ < 0.01) on the germination percentages. Priming improved the seedling characteristics in all samples, especially in -0.05 Mpa, but a decrease with decrease in osmotic potential.

• 한국환경과학회지
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• 제20권8호
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• pp.1049-1059
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• 2011

This paper examines the effects of the partial solar eclipse of 22 July 2009 across the Korean peninsular on surface temperature and ozone concentrations in over the Busan metropolitan region (BMR). The observed data in the BMR demonstrated that the solar eclipse phenomenon clearly affects the surface ozone concentration as well as the air temperature. The decrease in temperature ranging from 1.2 to $5.4^{\circ}C$ was observed at 11 meteorological sites during the eclipse as a consequence of the solar radiation decrease. A large temperature drop exceeding $4^{\circ}C$ was observed at most area (8 sites) of the BMR. Significant ozone drop (18~29 ppb) was also observed during the eclipse mainly due to the decreased efficiency of the photochemical ozone formation. The ozone concentration started to decrease at approximately 1 to 2 hours after the event and reached its minimum value for a half hour to 2 hours after maximum eclipse. The rate of ozone fall ranged between 0.18 and 0.49 ppb/min. The comparison between ozone measurements and the expected values derived from the fitted curve analysis showed that the maximum drop in ozone concentrations occurred at noon or 1 PM and was pronounced at industrial areas.

• Journal of Ginseng Research
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• 제9권1호
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• pp.15-23
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• 1985

The study was carried out to confirm the changes of soil physico-chemical properties and population of Fusarium solani by soil managements at preplanning fields for ginseng cultivation. Soil porosity and aggregation had been significantly increased during the managements while exchangeable nitrogen content and bulk density of the soil had been decreased. Available phosphate and exchangeable potassium content, in addition, seemed to be slightly increased. And soil aggregation showed positive correlation with clay, organic matter, soil moisture, and Ca content in the soil but negative with K content. Decrease rate of NH4-N and NO3-N content after soil managements were 55% and 41% in average, respectively. And better decrease effect for NH4-N was obtained in sand loam soil whereas no effect for NO3-N with soil textures. The more ploughing seemed to result in less propagules of F solani in the soil, however there was non significant decrease in population of the pathogen after the soil management. Number of F. solani in soil was significantly less in the fields where gramineous and leguminous crops had been grown as a precrop than other crops tested. Meanwhile there was no correlation between soil texture and population of the pathogen in the soil.

• Journal of Pharmaceutical Investigation
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• 제14권2호
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• pp.92-103
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• 1984

The action of debrisoquine on renal function in rabbits was studied. 1. When debrisoquine was given into ear vein, it did not affect on renal functin with smaller doses of 0.1 or 0.3mg/kg, while with higher dose of 1.0mg/kg it elicited the significant decrease of urine flow, renal plasma flow and glomerular filtration rate, and the increase of filtration fraction, and at the same time sodium excreted in urine, FENa (fractional excretion of sodium) and osmolar clearance were significantly decreased, and then it exhibited the increase of $K^+/Na^+$ ratio and no changes of $T^cH_2O$. 2. Debrisoquine (1.0mg/kg), when injected repeatedly into a vein, produced a more marked decrease of urine flow. 3. Debrisoquine induced-antidiuretic action was not affected by pretreatment with phentolamine (2mg/kg, i.v.), alpha-sympathetic blocking agent. 4. Debrisoquine given intracerebroventricularly did not produce a significant change on renal function in dose of 0.1mg/kg. These results suggest that debrisoquine produce the antidiuretic effect in rabbit, and the mechanism of its action is due to dual actions that are the decrease of hemodynamic effect and the facilitation of reabsorption of sodium in renal tubules.

• 멤브레인
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• 제18권3호
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• pp.256-259
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• 2008

본 연구에서는 poly(acrylonitrile-butadiene-styrene) (ABS)에 carbon graphite와 zeolite 4A를 첨가하여 복합 필름을 제조하고 공기와 수증기 투과 특성을 살펴보았다. 복합 필름의 경우 모든 경우에서 순수한 ABS에 비해서 산소와 질소의 투과도가 감소하였으며, 산소의 투과도 감소가 질소의 투과도 감소보다 약간 큰 관계로 산소/질소 선택도도 조금 감소하였다. 또한, 수증기 투과도도 순수한 ABS에 비해서 약 1/2로 감소하였다. 이러한 투과도의 감소는 ABS에 filler를 첨가함으로 인하여 물질 확산 경로의 tortuosity가 증가했기 때문인 것으로 생각된다.

• 오토저널
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• 제2권1호
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• pp.39-50
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• 1980

This paper presents the variations obtained in heat flow rate and engine performance of a four-stroke cycle Diesel engine when there were changes in the temperature of cooling water, compression ratio, injection timing of fuel, and other factors. Heat dissipation of engine cylinder was calculated by the heat transfer coefficient of Nusselt's empirical equation and the analysis of distribution of temperature in cylinder barrel was obtained by the finite element method of two-dimensional steady state heat conduction. In this experiment, the out side temperature of cylinder liner was measured by the data logger, and the temperature distribution of liner was computed by the analysis of triangular finite element model under the assumption due to surface heat flux of cylinder inner surface. The results obtained by this study are as follows. Under the given operating condition, the temperature distribution of cylinder liner by using finite element method shows that the mean temperature of barrel is in accordance with the experimental results of Eichelberg and temperature difference is lower than 4.23.deg. C. The heat dissipation of engine decrease in accordance with the decrease of piston mean velocity, compression ratio, and the increase of coolant temperature. Influence on the delay of injection timing of fuel brings about the decrease of heat rejection over the cylinder at constant test conditions.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.622-628
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• 2009

In the present study, the therapeutic potential of purified and well-characterized bacteriophages was evaluated in thermally injured mice infected with Klebsiella pneumoniae B5055. The efficacy of five Klebsiella phages (Kpn5, Kpn12, Kpn13, Kpn17, and Kpn22) was evaluated on the basis of survival rate, decrease in bacterial counts in different organs of phage-treated animals, and regeneration of skin cells as observed by histopathological examination of phage-treated skin. Toxicity studies performed with all the phages showed them to be non-toxic, as no signs of morbidity and mortality were observed in phage-treated mice. The results of the study indicate that a single dose of phages, intraperitoneally (i.p.) at an MOI of 1.0, resulted in significant decrease in mortality, and this dose was found to be sufficient to completely cure K. pneumoniae infection in the burn wound model. Maximum decrease in bacterial counts in different organs was observed at 72 h post infection. Histopathological examination of skin of phage-treated mice showed complete recovery of burn infection. Kpn5 phage was found to be highly effective among all the phages and equally effective when compared with a cocktail of all the phages. From these results, it can be concluded that phage therapy may have the potential to be used as stand-alone therapy for K. pneumoniae induced burn wound infection, especially in situations where multiple antibiotic-resistant organisms are encountered.

• 설비공학논문집
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• 제11권3호
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• pp.301-312
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• 1999

Experiments were carried out to evaluate performance of the cold air distribution systems with an ice storage tank in test room. Cold air distribution systems provide primary air for comfort conditioning or process cooling at coil discharge temperatures$4^{\circ}C$ to$11^{\circ}C$. The application of a cold air distribution system allows for the downsizing of air distribution equipment and central plant equipment when ice storage tank is used. The benefit of a cold air distribution system include a decrease in the floor-to-floor height, increase floor space, reduced building capital costs, reduced energy use and demand. The use of cold air distribution can result in the most cost effective system and is currently being implemented world wise as the new standard in air conditioning systems. In this study, the cold air distribution system is compared with the general ice storage system. Under the same cooling load conditions, experimental results show that the supply air volume of cold air distribution system decrease 38%, and decrease 45% flow rate of brine for the general ice storage system.