• 한국자동차공학회논문집
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• 제17권4호
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• pp.79-85
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• 2009

Low temperature combustion regime for the simultaneous reduction of nitrogen oxides ($NO_x$) and paticulate matter (PM) is demonstrated in single cylinder engine at various operating parameters, such as EGR rate, injection timing, EGR temperature, amount of fuel and swirl rate. Low temperature combustion is accomplished by high exhaust gas recirculation (EGR) rate in this study. Generally, the emission of $NO_x$ almost completely disappears and PM significantly increases in the first decreasing regime of oxygen concentration but after peaking about 10~12% oxygen concentration, PM then decreases regardless of fuel injection quantity. Low temperature combustion regime was extended by low EGR temperature, high injection pressure and low amount of fuel.

• 대한한의학회지
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• 제17권2호
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• pp.214-226
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• 1996

In an attempt to evaluate the effect of high and low concentration of Injinsaryungsan and high and low concentration of Sosihotang on cholestatic liver injery induced by $ANIT({\alpha}-naphthylisothiocyanate)$, biochemical changes in serum transaminase(GOT, GPT), alkaline phosphate, lactate dehydrogenase, total cholesterol, triglyceride, total-bilirubine were studied and the following results were obtained. 1. High concentration of Injinsaryungsan(2.2g／Kg) inhibited significantly the activity increases of GOT, GPT, ALP, LDH, TC, TG, T-Bilirubine induced by $ANIT({\alpha}-naphthylisothiocyanate)$. 2. Low concentration of Injinsaryungsan(1.1g／Kg) inhibited the activity increases of ALP, LDH, TC, TG with statistical significance, while inhibited the activity increase of GOT ,but with no statistical significance. 3. High concentration of Sosihotang(2.4g／Kg) inhibited the activity increases of LDH, TG, TC with statistical significance while inhibited the activity increases of GOT, GPT, ALP, T-bilirubine with no significance. 4. Low concentration of Sosihotang(1.2g／Kg) inhibited the activity increase of TG, while inhibited the activity increase of ALP, TC with no statistical sig-nificance, but didn't inhibite the activity increases of GOT, GPT, LDH, T-Bil. These results suggest that Injinsaryungsan has more significant effect on the liver injury induced by $ANIT({\alpha}-naphthylisothiocyanate)$ compared with Sosihotang and so can be applicable clinically to virus hepatitis and cholestatic liver injury. Further study will be required to evaluate the effect of Sosibotang on cholangitis and cholecystitis.

• 약학회지
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• 제56권3호
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• pp.180-185
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• 2012

The aim of present study was to investigate the possible influence and related mechanism of alcohol on the arterial contraction. Vascular contraction involves the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in alcohol-induced regulation. We hypothesized that alcohol plays a role in vascular contraction evoked by a vasoconstrictor in rat aortae regardless of endothelial function. Denuded arterial rings from male rats were used and isometric contractions were recorded using a computerized data acquisition system. Interestingly, alcohol at a low concentration (3% v/v) inhibited thromboxane $A_2$ or phorbol ester-induced contraction with endothelial function but at a high concentration (10%) didn't inhibit and rather increased the contraction in the denuded muscle. Therefore, alcohol at a low concentration decreases the contraction and alcohol at a high concentration increases the contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the regulation of contractility. In conclusion, alcohol has some effect on the regulation of contractility regardless of endothelial function.

• 한국환경과학회지
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• 제19권3호
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• pp.261-267
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• 2010

The variation of assimilable organic carbon(AOC) concentration at each condition of ozonation was investigated using a model water and drinking water resource. AOC concentration of model raw water and drinking water resource tended to increase at low ozone dose. The maximum AOC concentration was detected when the residual ozone begin to be measured. Also, the AOC concentration increase at pH 8 compared to both pH 6 and 7 while that for pH 9 decreased rapidly. The removal characteristics of trihalomethane formation potential(THMFP) by ozonation was also investigated. Unlike the trend of AOC, the THMFP concentration never increased by ozonation but decreased even at low ozone dosage. From these results, the ozone dosage would be effective to simultaneously decrease both AOC and THMFP.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.167-170
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• 2000

The purpose of study is to evaluate the effects of physical parameters on diesel biodegradation in diesel contaminated soil. The parameters applied are concentration, temperature, moisture contents, electron acceptor(O$_2$). The results of this study showed that diesel were degraded faster at high temperature and moisture contents than at low temperature and moisture content. However concentration effect study indicates that diesel were more faster degraded at low concentration than at high concentration. The results of electron acceptor test showed concentration of oxygen did not affect the biodegradation rate of diesel in oxygen condition(10, 20%) of this study.

• 한국자원식물학회지
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• 제20권6호
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• pp.544-547
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• 2007

The effects of hwangryun(Coptidis Rhizoma) on lowering lipid and oxidative stress in the induced obesity rat was observed. The concentration of plasma triglyceride in hwangryun treatment groups showed the low values compared to the control group, and as the increased hwangryun, the concentration of triglyceride decreased. The concentration of plasma total cholesterol decreased in all hwangryun treatment groups. However the concentration of plasma HDL-cholesterol and LDL-cholesterol showed no significantly difference in all the treatment groups. Thiobarbituric acid reactive substance(TBARS) concentration in plasma and liver showed low values in all hwangryun treatment groups compared to the control group. Glutathione peroxidase(GSH-Px) and superoxide dismutase(SOD) activities showed no significantly difference in all the treatment groups. However catalase(CAT) activity showed a tendence to increase in hwangryun groups, and in 200mg/kg hwangryun treatment group showed significantly a high value than the control group. Summarizing the results above, hwangryun has the functional materials that lowering lipid and works with oxidative stress.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2489-2497
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• 2023

Co and Eu impurities in the SSCs are nuclides that dominantly influence the neutron-induced radioactive inventory in metal and concrete radwastes (radioactive wastes) during NPP decommission. The impurity concentrations provided by NUREG/CR-3474 were used for the practical range of Co and Eu impurity concentrations to be applied to the code calculations. Metal structures near the core were evaluated to be ILW (intermediate-level waste) for the whole range of Co impurity concentration, so the boundary line between ILW and LLW (low-level waste) has no change for the whole concentration range provided by NUREG/CR-3474. Also, the boundary line between VLLW (very low-level waste) and CW (clearance waste) in the concrete shield could alter a little depending on the Eu impurity concentration within the range provided by NUREG/CR-3474. From this work, it is found that the concentration of material impurities of SSCs gives no critical impact on determining radwaste levels.

• 센서학회지
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• 제29권5호
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• pp.332-335
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• 2020

Drop casting, a solution process, is a simple low-cost fabrication technique that does not waste material. In this study, we elucidate the effect of the concentration of a InGaZnO solution on the electrical properties of drop-cast oxide thin-film transistors. The higher the concentration the larger the amount of remnant InGaZnO solutes, which yields a thicker thin film. Accordingly, the electrical properties were strongly dependent on the concentration. At a high concentration of 0.3 M (or higher), a large current flowed but did not lead to switching characteristics. At a concentration lower than 0.01 M, switching characteristics were observed, but the mobility was small. In addition to a high mobility, sufficient switching characteristics were obtained at a concentration of 0.1 M owing to the appropriate thickness of the semiconductor layer. This study provides a technical basis for the low-cost fabrication of switching devices capable of driving a sensor array.

• 한국농공학회논문집
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• 제52권5호
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• pp.37-45
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• 2010

Manure recycling as fertilizer is one of solutions for the environmental problem related with livestock manure treatment as well as the ocean dumping ban act prohibiting manure disposal to the ocean. For the manure disposal, forest area can be a candidate place because the area has a wide range of applicable sites. However, the manure application to the forest has a possibility of causing environmental impacts including water quality problems due to nutrient loading. Therefore it is necessary to investigate water quality impact from manure disposal to the forestry plantation. In this study, ground and soil water quality had been monitored in the bio-circulation experimental forest where low concentration liquid manure (LCLM) was applied. Soil and groundwater samples were collected and analyzed weekly from April to October in 2008 and 2009. The mean and variation of NO3-N concentration in soil water of LCLM treatment places showed higher concentration than the reference places declining during growing season. In the case of groundwater from monitoring well in the downstream of disposal site, the $NO_3$-N concentration was 3.59 mg/L in 2008 and 3.26 mg/L in 2009 in average showing higher concentration than the reference well although the concentration was not exceed the national drinking water standard. To investigate the source of nitrate, $\delta^{15}N$ isotope analysis was also implemented. Its result showed that the LCLM application could be the nitrate source requiring further long-term monitoring soil and water quality.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.892-895
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• 2006

The atmospheric effects on the retrieval of sea ice concentration from passive microwave sensors are examined using simulated data typical for the Arctic summer. The simulation includes atmospheric contributions of cloud liquid water and water vapor and surface wind on surface emissivity on the microwave signatures. A plane parallel radiative transfer model is used to compute brightness temperatures at SSM/I frequencies over surfaces that contain open water, first-year (FY) ice and multi-year (MY) ice and their combinations. Synthetic retrievals in this study use the NASA Team (NT) algorithm for the estimation of sea ice concentrations. This study shows that if the satellite sensor’s field of view is filled with only FY ice the retrieval is not much affected by the atmospheric conditions due to the high contrast between emission signals from FY ice surface and the signals from the atmosphere. Pure MY ice concentration is generally underestimated due to the low MY ice surface emissivity that results in the enhancement of emission signals from the atmospheric parameters. Simulation results in marginal ice areas also show that the atmospheric and surface effects tend to degrade the accuracy at low sea ice concentration. FY ice concentration is overestimated and MY ice concentration is underestimated in the presence of atmospheric water and surface wind at low ice concentration. In particular, our results suggest that strong surface wind is more important than atmospheric water in contributing to the retrieval errors of total ice concentrations over marginal ice zones.