• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.502-509
• /
• 2013

To estimate greenhouse gas (GHG) emission, we established inventory of conventional rice cultivation from farmers in Gunsan and Iksan, Jeonbuk province in 2011~2012. This study was to calculate carbon footprint and to analyse the major factor of GHGs. We carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we tried to suggest agricultural methods to reduce GHGs that farmers of this case study can apply. Carbon footprint of rice production unit of 1 kg was 2.21 kg $CO_2.-eq.kg^{-1}$. Although amount of $CO_2$ emissions is largest among GHGs, methane had the highest contribution of carbon footprint on rice production system after methane was converted to carbon dioxide equivalent ($CO_2$-eq.) multiplied by the global warming potential (GWP). Source of $CO_2$ in the cultivation of rice farming is incomplete combustion of fossil fuels used by agricultural machinery. Most of the $CH_4$ emitted during rice cultivation and major factor of $CH_4$ emission is flooded paddy field in anaerobic condition. Most of the $N_2O$ emitted from rice cultivation process and major sources of $N_2O$ emission is application of fertilizer such as compound fertilizer, urea, orgainc fertilizer, etc. As a result of sensitivity analysis due to the variation in energy consumption, diesel had the highest sensitivity among the energies inputs. If diesel consumption is reduced by 10%, it could be estimated that $CO_2$ potential reduction is about 2.5%. When application rate of compound fertilizer reduces by 10%, the potential reduction is calculated to be approximately 1% for $CO_2$ and approximately 1.8% for $N_2O$. When drainage duration is decreased until 10 days, methane emissions is reduced by approximately 4.5%. That is to say drainage days, tillage, and reducing diesel consumption were the main sources having the largest effect of GHG reduction due to changing amount of inputs. Accordingly, proposed methods to decrease GHG emissions were no-tillage, midsummer drainage, etc.

• Journal of Energy Engineering
• /
• v.7 no.1
• /
• pp.103-112
• /
• 1998

A high temperature fabric filter was developed and characterized in order to solve the various problems encountered in the operation of industrial fabric filters. Four kinds of dusts generated in the typical domestic industry were used for its characterization, coke dust from a steel manufacturing process, cement dust from a cement manufacturing process, fly ash from a fluidized-bed combustor, and incinerator ash from a waste plastics incinerator. The physical and chemical properties of the high temperature fabric filter were analyzed in terms of mean flow pore pressure, bubble point pore diameter, mean flow pore diameter, pore size distribution, and the changes in tensile strength and initial elastic modulus under $SO_2$ and $NO_2$ atmospheres. Pressure drop, dust penetration, and figure of merit for the fabric filter were also investigated in a bench-scale filter testing unit. The fabric filter developed in this study had good physical and chemical filter properties and showed a very applicability to typical industrial dusts treatments.

• Environmental and Resource Economics Review
• /
• v.25 no.4
• /
• pp.545-564
• /
• 2016

Recently as fine and ultra fine particles become major environmental issues in Korea, it is very important to develop effective solutions to air pollution. Accordingly this study aims at detecting causes of air pollution by using models and examining if diesel price increases contribute to reduction of diesel consumption and air pollution. TSP, PM10, $NO_X$, $SO_X$, CO, and VOC are included as major air pollutants. As a result, we found invert U shape curve between pollution and income for all air pollutants except CO. Consumer price index, coal power capacity, diesel consumption, frequency of yellow dust, number of natural gas buses, number of transport business, annual average temperature, number of manufacturing businesses are also influential in explaining causes of air pollution. As diesel price increases by 1%, air pollutants decline between 0.07~0.12% in the short run. Simultaneously, the additional revenue from increases in diesel prices might be transferred to support expansion of biofuel market. Also, stronger policy should be developed to mitigate the current air pollution problem.

• The Korean Journal of Nuclear Medicine
• /
• v.39 no.4
• /
• pp.257-262
• /
• 2005

Purpose: Gastric emptying scan (GES) is usually acquired up to 2 hours. Our study investigated whether a fraction of meal-retention in the stomach at 120 minutes (FR120) was predicted from the data measured for 90 minutes by using non-linear curve fitting. We aimed at saving the delayed imaging by utilizing mathematical models. Materials and Methods: Ninety-six patients underwent GES immediately after taking a boiled egg with 74 MBq (2 mCi) Tc-99m DTPA. The patients were divided into Group I ($T_{1/2}\;{\leq}90\;min$) and Group II ($90\;min). Group I (n=51) had 21 men and 30 women, and Group II (n=45) 15 men and 30 women. There was no significant difference in age and sex between the two groups. Simple exponential, power exponential, and modified power exponential curves were acquired from the measured fraction of meal-retention at each time (0, 15, 30, 45, 60, 75, and 90 min) by non-linear curve fitting ($MATLAB^{\circledR}$ 5.3) and another simple exponential fitting was performed on the fractions at late times (60, 75, and 90 min). A predicted FR120 was calculated from the acquired functional formulas. A correlation coefficient between the measured FR120 and the predicted FR120 was computed ($MedCalc^{\circledR}$ 6.0). Results: Correlation coefficients(r) between the measured FR120 and the predicted FR120 of each mathematical functions were as follows: simple exponential function (Group I: 0.8558, Group II: 0.5982, p<0.0001), power exponential function (Group I: 0.8755, Group II: 0.6008, p<0.0001), modified power exponential function (Group I: 0.8892, Group II: 0.5882, p<0.0001), and simple exponential function at the late times(Group I: 0.9085, Group II: 0.6832, p<0.0001). In all the fitting models, the predicted FR120 were significantly correlated with the measured FR120 in Group I but not in Group II. There was no statistically significant difference in correlation among the 4 mathematical models. Conclusion: In the cases with $T_{1/2}\;{\leq}90\;min$, the predicted FR120 is significantly correlated with the measured FR120. Therefore, FR120 can be predicted from the data measured for 90 minutes by using non-linear curve fitting, saving the delayed imaging after 90 minutes when $T_{1/2}\;{\leq}90\;min$ is ascertained.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.2
• /
• pp.67-78
• /
• 2007

The eye irritant test of lens washing agent, CLIWELL$^{TM}$ was conducted using Draize methods according to KFDA Guidelines. In addition, to test the potential toxicity of test articles, the ratio of inflammatory cells and non-inflammatory epitheloid cells was also observed using smear cytology methods against ocular discharge. At sacrifice, the histopathological changes on Cornea, Iris, Retina and Sclera were also observed in all animals. Slight irritancy of cornea and conjunctiva was observed at 1, 2 and 3 days after dropping in non-washing group. The MIOI of these points are detected as 4.50, 1.67 and 0.67, respectively. In washing group, slight irritancy of cornea and conjunctiva were observed at 1 and 2 days after dropping with MIOI as 0.67, respectively. Therefore, CLIWELL$^{TM}$ was considered as non-irritating materials because the MIOI is detected below 5.00 throughout the whole experimental periods in both washing and non-washing groups and the IAOI was also detected as 4.50. Except for significant increase of the inflammatory cell ratios in ocular discharge at 1 day after dropping of non-washing group compared to that non-treated intact eyes, no meaningful changes on smear cytology of ocular discharges are observed in this study. In addition, no abnormal histopathological changes on the cornea, iris, retina and sclera were also detected in CLIWELL$^{TM}$ dropping group compared to that of non-treated intact eyes.

• Journal of Korean Ophthalmic Optics Society
• /
• v.11 no.4
• /
• pp.299-310
• /
• 2006

The eye irritant test of lens washing agent, $SOLOCARE^{TM}$ was conducted using Draize methods according to KFDA Guidelines 1999-61. In addition, to test the potential toxicity of test articles the ratio of inflammatory cells and non-inflammatory epitheloid cells were also observed using smear cytology methods against ocular discharge. At sacrifice, the histopathological changes on Cornea, Iris, Retina and Sclera were also observed in all animals. Slight (1~2 degrees) irritancy of cornea and conjunctiva were observed at 1, 2 and 3 days after dropping in non-washing group. The MIOI of these points are detected as 4.33, 3.33 and 2.00, respectively. In washing group, slight irritancy of cornea and conjunctiva were restricted to 1 and 2 days after dropping with MIOI as 3.00 and 1.33, respectively. Therefore, $SOLOCARE^{TM}$ was also considered as non-irritating materials because the MIOI is detected below 5.00 throughout the whole experimental periods in both washing and non-washing groups and the IAOI is also detected as 4.33 (1 day after dropping). No meaningful changes on smear cytology of ocular discharges are observed in this study compared to that of non-treated intact eyes. In addition, no abnormal histopathological changes on the cornea, iris, retina and sclera were also detected in $SOLOCARE^{TM}$ dropping group compared to that of non-treated intact eyes.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.19-25
• /
• 2019

The CleanSYS(Clean SYStem) is operated to monitor air pollutants emitted from specific industrial complexes in Korea. So the industrial complexes without the system are directly monitored by the control officers. For efficient monitoring, studies using various sensors have been conducted to monitor air pollutants emitted from industrial complex. In this study, hyperspectral sensors were used to model and verify the equations for estimating the concentration of $NO_2$(nitrogen dioxide) in air pollutants emitted. For development of the equations, spectral radiance were observed for $NO_2$ at various concentrations with different SZA(Solar Zenith Angle), VZA(Viewing Zenith Angle), and RAA(Relative Azimuth Angle). From the observed spectral radiance, the calculated value of the difference between the values of the specific wavelengths was taken as an absorption depth, and the equations were developed using the relationship between the depth and the $NO_2$ concentration. The spectral radiance mixed gas of $NO_2$ and $SO_2$(sulfur dioxide) was used to verify the equations. As a result, the $R^2$(coefficient of determination) and RMSE(Root Mean Square Error) were different from 0.71~0.88 and 72~23 ppm according to the form of the equation, and $R^2$ of the exponential form was the highest among the equations. Depending on the type of the equations, the accuracy of the estimated concentration with varying concentrations is not constant. However, if the equations are advanced in the future, hyperspectral sensors can be used to monitor the $NO_2$ emitted from the industrial complex.

• Journal of Life Science
• /
• v.21 no.2
• /
• pp.211-220
• /
• 2011

This study tested the anti-obesity and hypolipidemic effects of red garlic extract in obese rats induced by a high fat diet over a period of 4 weeks. Red garlic extract of 15 brix was added in 1, 3, 5 and 7% ratios in diets. The obesity index and body fat content significantly decreased in rats fed a diet with over 3% red garlic extract compared to the control group. There was no significant difference in weight of visceral and epididymal fat in rats fed red garlic extract. Total lipid and triglyceride levels in serum were significantly decreased in a dose-dependent manner, and AI and CRF also fell. ALT and AST activities in groups fed red garlic extract were decreased compared to the control group. Total lipid level in liver tissue of the groups fed 5-7% red garlic extract exhibited a significant decrease compared to the control group. Total cholesterol and triglyceride levels in feces were significantly increased in rats fed a diet with over 5% red garlic extract. Lipid peroxide levels were significantly decreased in the groups fed diets with 5-7% red garlic and antioxidant activity in serum was significantly increased in the group fed a diet with 7% red garlic extract compared to the control group. Our results suggest that red garlic extract could have anti-obesity and hypolipidemic effects for suppressing obesity index and decreasing lipid profiles.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.1
• /
• pp.10-16
• /
• 2022

Interest in effluent treatment is currently increasing and the use of polymetric coagulants is considered as a pretreatment of physical filtration prior to effluent discharge to increase solids recovery. A jar test evaluated effluent treatment efficiency of polymeric coagulants for semi-recirculating aquaculture systems. The particle coagulation efficiency and distribution were evaluated at different polymer dosages in freshwater and seawater effluents. The polymer was added at 0.005-0.08 mL/g of total suspended solids (TSS) in the effluents. TSS in the supernatant after coagulation decreased with increasing polymer dose in the freshwater, while showing no corresponding changes with dose in the seawater. However, in all treatments for both effluents, the removal efficiency was above 90%, regardless of the dose in the tested range. Both the De Brouckere Mean Diameter (DBMD) and volumetric median diameter (VMD) were all above 100 ㎛ in the freshwater effluent. In the seawater effluent, the particle size appeared to be larger than that in freshwater, ranging from 400-1,000 ㎛ for both DBMD and VMD. Considering that the typical pore size of physical filtration in aquaculture is between 60 and 200 ㎛, the use of polymers is expected to improve the practicality of physical filtration for efficient treatment.

• Journal of Climate Change Research
• /
• v.3 no.2
• /
• pp.129-142
• /
• 2012

This study was carried out to evaluate carbon footprint during unhulled rice production and to compare mitigation technologies of methane, main carbon source during rice production, Carbon footprint of unhulled rice was a sum of $CO_2$ emission of agri-materials manufacture, rice cultivation and waste treatment. It was emitted 1.40 kg $CO_2$ during unhulled rice production, its distribution was 71.1% by $CH_4$ emission of rice cultivation, 11.8% of $N_2O$ emission by nitrogen application and 7.6% of complex fertilizer manufacture. $CH_4$ emission could be mitigated by some technologies; cultivation of the early maturing rice variety emitted lower by 44.4% than the mid maturing variety, intermittent drainage of submerged water by 43.8% than the continuous flooding condition, direct seeding by 32.0% than transplanting cultivation, no-ploughing by 20.9% than ploughing cultivation. It means that LCA on Global Warming Potential and the statistical data on innovated technical practice are key tools to systemize Measurable-Reportable-Verifiable (MRV) system for carbon footprint and carbon emission trade in the farm base.