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        검색결과 5

        1.
        2022.10 구독 인증기관·개인회원 무료
        An induction melting facility includes several work health and safety risks. To manage the work health and safety risks, care must be taken to identify reasonably foreseeable hazards that could give rise to risks to health and safety, to eliminate risks to health and safety so far as is reasonably practicable. If it is not reasonably practicable to eliminate risks to health and safety, attention have to be given to minimize those risks so far as is reasonably practicable by implementing risk control measures according to the hierarchy of control in regulation, to ensure the control measure is, and is maintained so that it remains, effective, and to review and as necessary revise control measures implemented to maintain, so far as is reasonably practicable, a work environment that is without risks to health or safety. The way to manage the risks associated with induction melting works is to identify hazards and find out what could cause harm from melting works, to assess risks if necessary – understand the nature of the harm that could be caused by the hazard, how serious the harm could be and the likelihood of it happening, to control risks – implement the most effective control measures that are reasonably practicable in the circumstances, and to review control measures to ensure they are working as planned.
        3.
        2013.11 서비스 종료(열람 제한)
        Hydrolysis of triacylglycerol(TAG) from fats and oils to glycerol and free fatty acid (FFA), also referred to as fat splitting, is an important reaction for the olechemical industry. Typically, hydrolysis is carried out at 100-260℃ and 100-7000 kPa using 0.4-0.15(w/w) initial water to oil ratio with or without catalysts. It is an endothermic reaction occurs in a stepwise manner where TAG is initially hydrolyzed to diacyglycerol (DAG) then to monoacylglycerol(MAG) and finally to glycerol. Water, in its subcritical state, can be used as both a solvent and reactant for the hydrolysis of triglycerides. subcritical water (150℃<T<370℃,0.4<p<22Mpa) can act as an acid or base catalyst. To investigate milder reaction conditions, in this study, waste cooking oil and fresh soybean oils will be hydrolyzed to free fatty acids with deionized water under SC CO2 medium in a batch reactor. Effects of the reaction temperature, time and solvent to feed ratio on FFA in the hydroysis at equilibrium will also observed for optimum conversion of oil. The reaction products will be analyzed by acid-base titration, GC FID and HPLC.
        4.
        2013.11 서비스 종료(열람 제한)
        Recently biodiesel has drawn much attraction as renewable enegy due to its environmental benefits and the fact that it is made from renewable resources. However, the production cost of biodiesel is one of the main hurdle to commercialize it. One of the way to reduce the biodiesel production cost is to use the waste cooking oil as feedstock. In the conventional transesterification process of waste cooking oils for biodiesel production, the presence of free fatty acids and water causes severe problems such as formation of soap and decreasing of catalyst yield. Much effort has been devoted to solve the above problems and one of the promising way is the supercritical methanol treatment which is performed at the methanol supercritical environment (>239.45℃, >8.10 Mpa)one of the serious problems of the application of SCM process for the biodiesel production is the tough operation condition(high pressure, high temperature. In this study, we have studied about the supercritical methanol treatment for the biodiesel production with the soybean waste cooking oil as a feedstock in the present of various heterogeneous solid catalysts such as mesoporous silica and acid-doped mesorpous silica. Biodiesel conversion was increased at more mild opreation condition to the previous studies by using the catalysts. The conversion was more enhanced by modifying the catalysts.
        5.
        2007.03 KCI 등재 서비스 종료(열람 제한)
        A new sprout-soybean cultivar, “Wonhwang” was developed at the Honam Agricultural Research Institute (HARI) in 2005. Wonhwang was selected from a cross between Camp and Myeongjunamulkong. The preliminary, advanced, and regional yield trials for evaluation and selection of Iksan45 were carried out from 2001 to 2005. This cultivar has a determinate growth habit with purple flower, grayish brown pubescence, grayish brow hilum, lanceolate leaflet shape and small seed size (10.0 grams per 100 seeds). The maturity date of Wonhwang is 7 days earlier than that of the check variety, Pungsan. It has good seed quality for soybean-sprout, and resistance to lodging. It has also been identified to have resistance to soybean mosaic virus (SMV) and necrotic symptom(SMV-N). The average yield of “Wonhwang” was 2.80MT/ha, which was higher by 4% than “Pungsannamulkong” at the regional yield trials.