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Department of Chemical EngineeringUtilizing carbon dioxide to valuable chemicals is attractive technology for reducing CO2 emission. Among the chemicals converted from CO2, formic acid is one of the most valuable chemicals. Efficient conversion of CO2 to formic acid by electro-biocatalytic system was reported without expensive cofactor and noble metals. In this study, Shewanella oneidensis MR-1 (S. oneidensis MR-1) and encapsulated Formate dehydrogenase1 from Methylobacterium extorquens AM1 (MeFDH1) were applied to electro-biocatalytic reaction as a whole cell and encapsulated biocatalyst, respectively. First, S. oneidensis MR-1, when aerobically grown in Luria-Bertani (LB) medium, exhibited its ability for the conversion of CO2 into formic acid with productivity of 0.59 mM???hr-1 for 24 hr. In addition, CO2 reduction reaction catalyzed by S. oneidensis MR-1, when anaerobically grown in newly optimized LB medium supplemented with fumarate and nitrate, exhibited 3.2-fold higher productivity (1.9 mM???hr-1 for 72 hr). Second, previous study has demonstrated that electro-biocatalytic conversion of CO2 to formic acid by engineered MeFDH1 shows higher productivity than wild type. To increase physical strength, stability, reusability of MeFDH1, MeFDH1 was encapsulated in pure alginate and alginate silica hybrid beads. Michaelis-Menten kinetic constants demonstrated that binding affinity and maximum reaction rate of both encapsulated MeFDH1 were declined. Compared with pure alginate beads (5.4%), alginate-silica hybrid beads (67.4%) exhibited more higher recycling productivity after 4 cycles. These results show that the immobilization of MeFDH1 through encapsulation of by alginate-silica hybrid is a more suitable method to recycle formate production and prevent leakage of MeFDH1.ope

Price Equivalent Impacts of the DDA in the Korean Raw-milk Market

This study estimates the potential impacts of the Doha Development Agenda (DDA) on the Korean raw-milk market. The DDA has not reached an agreement yet. Although there are different attitudes about several issues such as Special Safeguard Mechanism (SSM), Sensitive Products (SP), and Tariff Rate Quota (TRQ) creation, WTO member countries have reached an agreement for major issues of the modalities in the DDA. Hence, this study estimates the impacts of the DDA that will finally reach an agreement sooner or later. For estimating the impacts of the DDA, this study makes a dairy trade model for the Korean dairy industry and measures the impacts of the DDA in terms of raw-milk price for fluid use incurred by further tariff cuts in the Korean dairy market by the DDA. This study considers several scenarios because the status of Korea is not settled yet and a country can select dairy products as sensitive products, special products, or general products and a country can select different options in each category. The results of this study can be used for preparing policies for subsidizing the domestic raw-milk producers to rebalance their loss in the raw-milk market incurred by the DDA.DDA, dairy, milk, tariff, price equivalent, Agricultural and Food Policy, Demand and Price Analysis, International Relations/Trade, Livestock Production/Industries,

Color-Shift Measurement in Microlensing-Induced Stellar Variation from Future Space-Based Surveys

If a microlensing event is caused by a star, the event can exhibit change in color due to the light from the lens. In the previous and current lensing surveys, the color shift could not be used to constrain the lens population because the blended light responsible for the color shift is mostly attributed to nearby background stars rather than the lens. However, events to be observed in future space-based surveys do not suffer from blending and thus the color information can be used to constrain lenses. In this paper, we demonstrate the usefulness of future surveys in measuring color shifts. By conducting simulation of galactic lensing events based on the specification of a proposed space-based lensing survey, we estimate that the shift in the color of $R-H$ will be measured at 5$\sigma$ level for $\sim 12$ of events that occur on source stars with apparent magnitudes brighter than $J=22.5$. Color-shifted events tend to have high magnifications and the lenses will have brightnesses equivalent to those of source stars. The time scales of the color-shifted events tend to be longer than those without color shifts. From the mass distribution of lenses, we find that most of the color-shifted events will be produced by stellar lenses with spectral types down to mid M-type main sequence stars.Comment: 5 pages and 3 figure