• Korean Journal of Pharmacognosy
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• v.21 no.1
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• pp.74-82
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• 1990

The effects of naturally occurring furanocoumarins on cytochrome P-450 have been investigated in rat liver microsomes. Incubation of microsomes with an NADPH-generating system and four furanocoumarins such as imperatorin, isoimperatorin, phellopterin and byakangelicin at $37^{\circ}$ in vitro resulted in a significant destruction of cytochrome P-450. A single treatment(50 mg/kg, i.p.) of rats with each furanocoumarin caused a rapid loss of cytochrome P-450 accompanied by the loss of heme from the microsomes but not by the loss of cytochrome $b_5$. It is suggested that cytochrome P-450 is specifically destroyed by furanocoumarins in a metabolic process involving destruction of its heme group and as a consequence, hepatic enzyme activities are depressed markedly.

• Bulletin of the Korean Chemical Society
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• v.6 no.6
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• pp.337-343
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• 1985

A statistical mechanical approach to elucidate the solvent effects on the high polymer solutions has been carried out on the basis of the simple model of liquids improved by Pak. In our works, the partition function of the polymer solutions is formulated by the lattice model and our simple treatment of liquid structures. For the ideal polymer solutions proposed by Flory, thermodynamic functions of the polymer solutions are obtained and equations of mixing properties and partial molar quantities are derived from the presented partition function of the polymer solutions. Partial molar quantities are calculated for the rubber solutions in carbon disulfide, benzene and carbon tetrachloride. Comparisons have been made between our equations and those of Flory's original paper for partial molar properties of the rubber-benzene system. Comparing the experimental data of the osmotic pressure of polystyrene-cyclohexane system with our calculated values and those of Flory's, our values fit to the agreeable degrees better than those of Flory's.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.2
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• pp.127-135
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• 1997

Experiments have been conducted to investigate emission characteristics of compressed natural gas fueled vehicle(CNGV) by the FTP 75 mode test. Its purification technologies were also investigated. It was found that CNGV was operated on the rich A/F condition by comparison with gasoline vehicle. The Pd catalyst was higher in methane purification performance than Pt and Pd/Pt/Rh catalysts. Up to 60% portion of the accumulative HC emissions(that contains above 80% methane) form CNGV occurs during the first phase of the FTP 75 mode. CO that is exhausted at rich conditions of the air-fuel ratio more than lean conditions should be used for the catalytic reduction of NOX, because the methane is not the effective reduction for NOX in the CNGV with 3-way catalyst system.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.138-144
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• 2001

This study was carried out to investigate characteristics and Pb(II) removal effect of natural clays in the batch mode test. The effect of parameters such as temperature, adsorption time and coexisting cations on the sorption ability and characteristics was investigated to find out whether the clays could be used as adsorbents. Several natural clays from domestic have been investigated to have high specific surface area and have minerals such as SiO$_2$ and $Al_2$O$_3$. As a result, removal effects of Pb(II) on clays were reached at equilibrium in aqueous solutions by stirring about 20 minutes. The removal effect of Pb(II) was best for Kang Jin clay than other clays in terms of fixed time. Adsorption efficiency was not influenced by the possibility of continuous treatment system of wastewater which contain heavy metals by using natural clays from domestic.

• Journal of the Korean Wood Science and Technology
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• v.22 no.4
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• pp.13-18
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• 1994

Sapwood samples of pitch pine were treated with disodium octaborate alone by dip-diffusion, or in combination with water-repellent preservative(WRP) and methyl metacrylate(MMA). Treated samples were subjected to an accelerated leaching test for determining the improvement of leaching resistance and to soft rot and mold tests for evaluating the increase in bioefficacy, due to the addition of WRP and MMA applied as a second treatment. The addition of WRP and MMA retarded leaching of boron to some extent from treated samples and this retardation can be explained by improved water repellency of WRP and MMA treated samples. Borate /WRP and borate /MMA systems will not qualify borate treated wood for ground and fresh water contact use but may improve performance of borate treated wood in above-ground applications not subjected to continuous wetting conditions. Bioefficacy against soft rot fungi and mold fungi was improved by a second treatment with WRP. However, improvement in the performance of borate /MMA systems was not observed. Considering improvement in both resistance of leaching and bioefficacy against micro fungi by the treatment of WRP and MMA, simultaneously, the dual treatment of borate treated wood by MMA containing co-biocides might be believed as an ideal treatment system.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.105-112
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• 2005

This study aims at evaluating the environmental impacts stemmed from the End-of-Life Vehicle(ELV) treatment systems in Korea, using Life Cycle Assessment(LCA) method. In this study, both environmental burden from the ELV dismantling process & recycling processes and environmental benefit which were derived from the avoided environmental impacts by substituting recycled materials for virgin materials were considered. First of all, the key issues which were defined as the environmental aspects that account for more than $1\%$ out of the total environmental impacts were identified from the Life Cycle Impact Assessment(LCIA). $CO_2$, crude oil, natural gas, coal, etc. were found out to be the key issue parameters. From the LCI Analysis and LCIA studies, it was shown that the significant environmental aspects were related with the recycling process of ferro scrap, the shredding process of compressed car bodies and the dismantling process of end-of-life engines. In particular, the recycling process of ferro scrap has the most significant effects on the environmental impacts of the ELV treatment systems. Based on these results, it is recommended to improve the recycling process of ferro scrap in order to make the ELV treatment systems more environmentally sound.

• Journal of Korean Society on Water Environment
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• v.38 no.5
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• pp.231-239
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• 2022

In this study, we applied ENERWATER to evaluate the energy consumption labeling of wastewater treatment plants in Korea using the Korea sewerage statistics data. The results showed that the energy label status was excellent in the SBR process for small and medium-scale wastewater treatment plants and the A2O process for large-scale wastewater treatment plants. The energy labeling of wastewater treatment plants of 50,000 tons capacity was excellent. The statuses of metropolitan cities and Jeollanam-do province were excellent. We analyzed the effects of renewable energy on wastewater treatment plants' energy consumption and found out that digestion gas for large-scale plants and photovoltaic energy for small-scale plants were effective in improving energy labeling. In addition, we compared the energy labels of four wastewater treatment plants in "Z" city and wastewater treatment plant "X" had the best energy label, and the wastewater treatment plants "V" and "Y" had to be selected as priorities for the energy diagnosis and improvement project. In a comprehensive conclusion, the applicability of ENERWATER was confirmed based on sewage statistics data and labeling can be used to set priorities for the energy diagnosis and improvement project.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.5
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• pp.97-108
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• 1997

Natural wastewater treatment systems using the constructed wetland system were evaluated for the wastewater from the industrial complex in rural areas. For the treatment of wastewater from the industrial complex in rural area, a pilot plant of the constructed wetland system was installed at Baeksuk agri-industrial complex in ChunahnCity, Chunchungnam-Do. The experiment with this pilot plants was performed for 1996 and 1997. Results of the study were summarized as follows. For the BOD and COD, when the pollutant loading of them was about 1 3.8g/$m^2$. day (the concentration was l24.0mg/${\ell}$) arid 24.4g/$m^2$.day(the concentration was 220.Omg/${\ell}$), the removal rate of them was high, 90.2% and 93.4%, respectively. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which consist of soil and plants. For the T-N and T-P, when the influent pollutant loading of them were moderately high, 2.8g/$m^2$.day to 7.4g/$m^2$. day(concentration 25.0mg/${\ell}$ to 49.7mg/${\ell}$) for T-N and 1.0g/$m^2$.day to 2.6g /$m^2$.day(concentration 8.6mg/${\ell}$ to 14.7mg/${\ell}$) for T-P, the removal rate of them were 86.5% and 94.0%, respectively. The removal rate by the flow distance increased rapidly in the first 4m from the inlet zone, and gradually there after. The width of system was 2m. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural areas. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.239-245
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• 2014

Complete denture prosthodontics includes replacement of natural teeth and associated maxillary and mandibular structures for full edentulous patients. The final objectives of prosthodontic treatment include esthetic and functional rehabilitation. Because the esthetic demand of senior patients has increased esthetic requirement should not be overlooked in denture treatment. In complete denture treatment, attempts have been made to reproduce tooth wear, arrangement, recession of cervical gingiva, staining, improved gingival shade and so on. This 61 year old female patient came to the Department of Prosthodontics with the chief complaint that dentures made 5 years ago in a local clinic were broken and did not fit well. The patient put more emphasis on fabrication of natural and esthetic dentures than recovery of masticatory function. Remake of maxillary complete denture and mandibular implant retained overdenture was planned. In order to create esthetic and natural contour, Aesthetic Color Set Easy system$^{(R)}$ (Candulor dental GmbH, Wangen, Germany) was used to make complete dentures reproducing various gingival shades. Patient's esthetic satisfaction was high. When complete denture prosthodontics treatment involves appropriate expression of individual characteristics in addition to proper selection of esthetic materials, treatment will give satisfaction to both dentist and patient.

• Korean Journal of Pharmacognosy
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• v.37 no.4 s.147
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• pp.307-313
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• 2006

Reactive oxygen species (ROS) and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic nephropathy by hyperglycemia. To find natural agents improving diabetic nephropathy, 63 natural resources which used to the treatment of diabetes mellitus in a folk remedy were investigated with an in vitro system employing radical scavenging activity and inhibitory activity of AGEs formation. In results, the extracts of Aspalathus linearis, Rubus coreanus, Rosa rugosa, and Epimedium koreanum significantly inhibited the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical with $IC_{50}$ values less than $10{\mu}g/ml$. The extracts of Zea mays, Cucurbita moschata, Cudrania tricuspidata, and Aspalathus linearis effectively reduced the formation of AGEs compared with the positive control $N-acetyl-_L-cystenine$ (NAC) and aminoguanidine (AG). In addition, the extracts of Aspalathus linearis, Commelina communis, Cornus officinalis, and Lespodeza cuneata showed the all inhibitory activity against DPPH radical and AGEs formation. Also, these resources definitely showed the radical scavenging activity against peroxynitrite $(ONOO^-)$ and hydroxyl radical $({\cdot}OH)$ relating to high glucose-induced ROS production. Thus, these results suggest that some natural resources may regulate the initiation and progression of diabetic nephropathy through inhibition of ROS production and AGEs formation.