We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear recoils and γ's below 10 keV. The response of CsI crystals to nuclear recoil was studied with mono-energetic neutrons produced by the 3 H(p,n) 3 He reaction. This was compared to the response to Compton electrons scattered by 662 keV γ-ray. Pulse shape discrimination between the response to these γ's and nuclear recoils was studied, and quality factors were estimated. The quenching factors for nuclear recoils were derived for both CsI(Na) and CsI(Tl) crystals.

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A techno-economic analysis was conducted to investigate the feasibility of a gasification-based hybrid biorefinery producing both hydrogen gas and polyhydroxyalkanoates (PHA), biodegradable polymer materials that can be an attractive substitute for conventional petrochemical plastics. The biorefinery considered used switchgrass as a feedstock and converted that raw material through thermochemical methods into syngas, a gaseous mixture composed mainly of hydrogen and carbon monoxide. The syngas was then fermented using Rhodospirillum rubrum, a purple non-sulfur bacterium, to produce PHA and to enrich hydrogen in the syngas. Total daily production of the biorefinery was assumed to be 12 Mg of PHA and 50 Mg of hydrogen gas. Grassroots capital for the biorefinery was estimated to be $55 million, with annual operating costs at $6.7 million. With a market value of $2.00/kg assumed for the hydrogen, the cost of producing PHA was determined to be $1.65/kg.