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        검색결과 453

        401.
        2017.05 서비스 종료(열람 제한)
        Elemental analysis, calorific value, etc. were measured to obtain basic information such as decomposition temperature and required oxygen amount for thermal treatment of waste containing chlorine-based flame retardant. Moisture, flammability and ash content of polyurethane foam were high in water, flammable rubber sheet in case of ash and flame retardant rubber sheet in case of ash. As a result of thermogravimetric analysis, the weight change in the range of 300 ~ 600 ℃ was large. The content of chlorinated flame retardant agent was analyzed to be higher than that of polyurethane foam (4,253.09 mg/kg), cell phone case (cloth, leather) 628.29 mg/kg and flame retardant rubber sheet 341.91 mg/kg. Chlorinated flame retardant materials, TDCP and TDCPP, were not detected in all samples. As a result of the decomposition tests for chlorine-based flame retardants at 850 ℃ and 1,100 ℃, chlorine-based flame retardant components were not detected in exhaust gas at all at 1,100 ℃ as well as at 850 ℃ in all samples including mobile phone cases, flame retardant rubber sheets and car seats. As a result of calculating the conversion rate for total chlorine value, it showed more than 99% even at 850 ℃ as well as at 1,100 ℃. Considering the decomposition rate in laboratory experiments of chlorine-based flame retardant-containing wastes, it is considered possible to incinerate at a scale of 2 ton/hour or more, which is the existing incineration facility. It is judged that it is not necessary to set separate operating conditions or preventive facility standards since the material is decomposed sufficiently at 850 ℃ or more. However, considering the possibility of dioxin or unintentional persistent organic pollutants, it is considered appropriate to operate at above 1,100 ℃.
        402.
        2017.05 서비스 종료(열람 제한)
        As a result of analyzing the contents of organic chlorine pesticide-containing wastes, HCB 421.8 ng/g, Endosolfan- 2 73.044 ng/g, PeCB 53.972 ng/g, Endosolphan-1 43.649 ng/g respectively. In the case of liquid pesticides, the HCB concentration was the highest at 167.489 ng/g, similar to that of the solid phase, followed by PeCB at 23.462 ng/g. As a result of decomposition experiments on total OCPs among the pesticide liquid and solid phase components, initial concentrations were 597.384 ng/L for liquid pesticides and 198.176 ng/L for solid pesticides. However, the final effluent gas after decomposition showed a decomposition rate of more than 99.99% at a minimum of 0.005 ng/L and a maximum of 0.055 ng/L. Degradation test results for 25 species of OCPs such as PeCB, HCB, and Endosolfan for pesticide solid phase and liquid phase at reaction temperatures of 850℃ and 1,100℃. Of the 25 OCPs in the exhaust gas, trace amounts of PeCB and HCB were detected in the range of 0.006 to 1.025 ng/L at 1,100 ℃ and 850 ℃, and 23 OCPs were not detected. In the case of pesticides, the method of high temperature incineration and high temperature melting is proposed as the designated waste, but detailed methods of treatment conditions such as incineration conditions are not presented. Organochlorine pesticides were decomposed smoothly at 850 ℃ as well as incineration temperature of 1,100 ℃. However, since the dioxin concentration in exhaust gas exceeds 850 ℃, it is safe to operate at more than 1,100 ℃ in order to prevent the possibility of dioxin in advance.
        403.
        2017.05 서비스 종료(열람 제한)
        WtE of MSW plays a crucial role in renewable energy production in Korea. Municipal solid waste (MSW) is an important energy resource for combined heat and power (CHP) production. This study investigated an increasing method to the power generation efficiency by MSW to energy (WtE) plants in South Korea and discussed the issues related to energy efficiency improvement. To achieve energy efficiency improvement is used to lower temperature for emission gas at catalyst inlet, or to reduce/stop using steam to reheat emission gas. Saved energy from this process can be used as power source in order to increase generation efficiency. It is possible to increase denitrification efficiency by maintaining the temperature of emission gas for catalyst denitrification. The temperature of emission gas of which moisture is increased to saturation point (relative humidity of 100%) at the exit of wet scrubber is between 50 and 60℃. This means there should be reheating of emission gas with the approximate temperature of 150℃. Dry emission gas treatment, on the other hand, is the technology to increase generation efficiency by using highly efficient desalination materials including highly-responsive slaked lime and sodium type chemicals in order to comply with air pollution standards and reduce used steam volume for reheating emission gas. If dry emission gas is available, reheating is possible only with the temperature of 45℃ in order to expect generation efficiency by reducing steam volume for reheating.
        404.
        2017.05 서비스 종료(열람 제한)
        When adopting drain close system, the temperature of emission gas at the boiler exit is set high by spraying and evaporating drained water on quencher tower. According to applying drain close system boiler and power generation efficiency were decreased. In case of the water close system is not applied to treat the wastewater from incineration facility, the economizer outlet temperature can be reduced to 190∼220℃. And this leads to the increased ability of boiler's heat recovery. However, the temperature of emission gas at economizer exit should be set at 250℃ or higher if applying drain close system (minor conditions can affect as well). Boiler efficiency and generation efficiency can be improved by comparing the temperature of emission gas at economizer exit at 190℃ without the introduction of drain close system and 250℃ with drain close system. There are three types of white plume reduction equipment: one is offline type to blow air into chimney through heat source and exchange points after heating the air by using steam from equipment like boiler; another is in-line type to blow air into chimney through heat exchanger of combustion emission gas (mainly boiler exit); and the other is to blow air into chimney through hot wind burner by using fuels including kerosene. At a facility with white plume reduction equipment equipped with 5℃ of outdoor temperature and 60% of humidity, power generation volume and generation efficiency can be improved by using leftover steam for steam turbine from suspension of using white plume reduction equipment.
        405.
        2017.05 서비스 종료(열람 제한)
        The Stockholm Convention is an agreement to reduce POPs use, production and emissions. POPs are highly toxic substances and can not be decomposed in their natural state. It has the characteristic of long distance movement. In this study, we calculated the theoretical air volume based on the result of element analysis. Considering that the inside of the reactor is small, more than 10 times of the air ratio was injected. Also, the retention time was set to 4 seconds or longer by giving a margin. The incineration temperature was 850℃ and 1,100℃ degrees. As a result of thermogravimetric method analysis, the weight of chlorine-based flame retardant-containing wastes was 300∼600℃, and that of organic chlorine-based pesticides was 200∼400℃. On the basis of this, it was experimentally investigated whether the environmentally stable incineration is achieved when the sample is thermally treated using lab-scale, 1 kg/hr. As a result of analyzing five kinds of exhaust gas, the concentration of O2 was high, but the amount of CO was decreased. It is considered that complete combustion is difficult because of the small size of the furnace due to the nature of lab-scale. The chlorinated flame retardants had a decomposition rate of 100 % and the average organochlorine pesticides were 99.9935%. Considering the decomposition rates of chlorinated flame retardants and organochlorine containing pesticide derived wastes derived from this study, incineration treatment at over 2 tons/hour, which is a conventional incinerator, is considered to be possible. Considering the occurrence of dioxins and unintentional persistent organic pollutants, it is considered possible to operate at more than 1,100℃.
        406.
        2012.04 KCI 등재 서비스 종료(열람 제한)
        Effects of nitrogen (N), phosphorous (P) and potassium (K) on the shoot and bulb growth of wild garlic (Allium victorialis var. platyphyllum) were studied by adopting in vitro culture. These macronutrients influenced the growth of both the shoot and bulb of garlic depending upon their application doses. A minimum of 3% potassium nitrate (KNO3) as a source of nitrogen was found to be critical for shoot elongation while higher concentrations were inhibitory. Garlic bulb growth was profuse on the usual KNO3 strength and sucrose (7%), followed by KNO3 (9.4 mM) supplement. On providing 41.22 mM ammonium nitrate (NH4NO3) as nitrogen source highest shoot growth was observed while 82.45 mM NH4NO3 as a source of nitrogen supported high bulb growth. With regard to potassium a good shoot growth was observed in medium that contained 0.31 mM KH2PO4 and 3% sucrose, while bulb growth was high on 2.5 mM KH2PO4 and 7% sucrose. These experiments may thus direct the development of excellent growth conditions for the commercial production of edible wild garlic.
        407.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        Green manure crops play an inportant role in organic farming. Field experiment was conducted at paddy soi1 (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentíc Endoquepts) ín 2008/2009 to 2009/2010 at the Natíonallnstítute of Crop Science (NICS), RDA, Suwon, Gyeonggí provínce, Korea. This expe꺼ment was carried out to evaluate the biomass of haíry vetch (Vicia víllosa) and growth of rice (Oryza satíva) by cjífferent seedíng rates. Seeding rates of hairy vetch consisted of 30, 60, and 90 kg ha-' by broadcasting before rice harvesting. The biomass af)d nitrogen production of hairy vetch were not significantly different between 60 kg ha-’ and 90 kg ha-’ of seeding rates. Also, rice yield was not siginicantly differnt between seeding rate 60 kg ha-’ of hairy vetch and conventional pratice for two years. Therefore, we suggested that seeding rate of hairy vetch should be reduced by continuous cropping and incoportion of hairy vetch under rice-based cropping system.
        409.
        2010.09 서비스 종료(열람 제한)
        Controllable transgenic expression systems in transgenic animal model are valuable to the development of therapeutic approaches in human medical fields. The aim of this study was to 1) produce a transgenic cloned dog using inducible tetracycline vector system, and 2) investigate whether the transgenic cloned dog could be induced the transgene expression using doxycycline (Doxy). Canine fetal fibroblasts were infected with retroviral vectors designed to express the enhanced green fluorescent protein (eGFP) gene under the control of tetracycline-inducible promoter. For somatic cell nuclear transfer (SCNT), nucleus of an in vivo matured oocyte was removed and an eGFP expressed cell cultured with 1 ㎍/㎖ of Doxy was injected. After electrical fusion and chemical activation, the reconstructed embryos were transferred to a recipient and pregnancy diagnosis was performed by ultrasonography. Experiment I evaluated the mean fluorescence intensity (MFI) of infected cells while the cells were cultured in the presence of 1 ㎍/㎖ of Doxy for 5 days, and then in the absence of Doxy for 7 days using fluorescence-activated cell sorter. Experiment II was designed to produce an eGFP controllable transgenic cloned dog via SCNT. For verification of transgenic dog, experiment III was performed Southern Blot analysis and observation in vivo regulation of eGFP expression in the cloned dog treated with 100 ㎎/㎏ of Doxy every 2 days for 2 weeks under ultraviolet light. In experiment IV, western blot was used to detect eGFP increase and decrease in skin tissues of transgenic dog under the presence or absence of Doxy. In the results of experiment I, the MFI for infected cells was rapidly increased to approximately 42.3 times after 3 day-treatment compared to pre-treatment and quickly decreased 3 days after ceasing the treatment. In experiment II, a total of 203 embryos were transferred to nine recipients and three pregnant delivered three pups (Tet-on eGFP 0, Tet-on eGFP 1, and Tet-on eGFP 2) by C-sec and Tet-on eGFP 2 among them is still alive. All cloned pups were genetically identical to the donor cell. Tet-on eGFP 2 showed an apparent in vivo eGFP expression on her body after Doxy administration in experiment III. The result of Sothern blotting showed that the transgene insertion was detected from the three cloned dogs and all organs of Tet-on eGFP 1. Experiment IV indicated that a robust eGFP expression in skin tissue of Tet-on eGFP 2 rapidly increased after Doxy treatment and gradually decreased to basal level on 9 weeks after ceasing the treatment. In conclusion, we report here for the first time an inducible transgenic system in canine species and it can stably induce the transgene expression at intended time. This study has demonstrated the capacity to generate transgenic model dog which could regulate the transgene and it would contribute to human medical research fields.
        410.
        2009.03 KCI 등재 서비스 종료(열람 제한)
        "Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.
        411.
        2009.01 서비스 종료(열람 제한)
        The cloning of canids was succeeded in 2005, several years after the birth of Dolly the sheep and also after the cloning of numerous other laboratory and farm animal species. The delay of successful somatic cell nuclear transfer (SCNT)was due to the unique reproductive characteristics of the female dogin comparison to other domestic mammals, such as ovulation of immature canine oocyte and a requirement of 25 days for the completion of meiosis within the oviduct (Holst & Phemister, 1971). When the technology for the recovery of in vivo matured oocyte was established, the application of cloning also became possible and cloned dog offspring were obtained. This report summarizes the progress of technical procedures that are required for cloning canids and the application of this technique. The first cloned dog, Snuppy, was achieved using an in vivo-matured oocyte which was enucleated and transferred with an adult skin cell of male Afghan hound. After establishment of a criterion of well-matured oocyte for the improvement of SCNT efficiency, we obtained three cloned female Afghan hound and a toy poodle cloned from 14 year-old aged Poodle using SCNT through this factor. To date, cloned dogs appeared to be normal and those that have reached puberty have been confirmed to be fertile. Through application of canine SCNT technique, first, we demonstrated that SNCT is useful for conserving the breed of endangered animal from extinction through cloning of endangered gray wolves using inter-species SCNT and keeping the pure pedigree through the cloning of Sapsaree, a Korean natural monument. Secondly, we showed possibility of human disease model cloned dog and transgenic cloned dog production through cloning of red fluorescent protein expressing dog. Finally, SCNT can be used for the propagation of valuable genotypes for making elite seed stock and pet dog. In summary, dog cloning is a reproducible technique that offers the opportunity to preserve valuable genetics and a potential step towards the production of gene targeted transgenic cloned dogs for the study of human diseases.
        420.
        2003.09 서비스 종료(열람 제한)
        DNA methylation is involved in epigenetic processes such as X-chromosome inactivation, imprinting and silencing of transposons. DNA methylation is a highly plastic and critical component of mammalian development The DNA methyltransferases (Dnmts) are responsible for the generation of genomic methylation patterns, which lead to transcriptional silencing. The maintenance DNA methyltransferase enzyme, Dnmt 1, and the de novo methyltransferase, Dnmt3a and Dnmt3b, are indispensable for development because mice homozygous for the targeted disruption of any of these genes are not viable. The occurrence of DNA methylation is not random, and it can result in gene silencing The mechanisms underlying these processes are poorly understood. It is well established that DNA methylation and histone deacetylation operate along a common mechanistic pathway to repress transcription through the action of methyl-binding domain proteins (MBDs), which are components of, or recruit, histone deacetylase (HDAC) complexes to methylated DNA. As a basis for future studies on the role of the DNA-methyl-transferase in porcine development, we have isolated and characterized a partial cDNA coding for the porcine Dnmt1. Total RNA of testis, lung and ovary was isolated with TRlzol according to the manufacture's specifications. 5 ug of total RNA was reverse transcribed with Super Script II in the presence of porcine Dnmt 1 specific primers. Standard PCRs were performed in a total volume of 50 ul with cDNA as template. Two DNA fragmenets in different position were produced about 700bp, 1500bp and were cloned into pCR II-TOPO according to the manufacture's specification. Assembly of all sequences resulted in a cDNA from 158bp of 5'to 4861bp of 3'compare with the known human maintenance methyltransferase. Now, we are cloning the unknown Dnmt 1 region by 5'-RACE method and expression of Dnmt 1 in tissues from adult porcine animals.
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