We show that 1% Sm-doped fluoroaluminate (FA) glass plate and a suitably modified fluorescence confocal microscope provide an excellent radiation detection platform for high-dose measurements at high resolution down to the micron scale. We have used a custom-modified fluoroscopic confocal microscope apparatus to scan, separate, detect, and digitize the photoluminescence signals from Sm 3+ and Sm 2+ ions in both FA and fluorophosphates (FP) glasses within a selected focal depth of the microscope below the sample surface. The response (R) of Smdoped FA and FP glass plates to incident x-ray radiation was studied in detail in which R was defined as the difference in the ratio of photoluminescence (PL) signals from Sm 2+ and Sm 3+ before and after irradiation. We report on a number of important issues related to the use of these Smdoped FA and FP glass plates in microbeam radiation therapy (MRT) dosimetry: The dependence of the Sm 3+ to Sm 2+ conversion, and hence R on the dose rate over some four orders of magnitude; the energy dependence of R at a given dose rate for both FA and FP samples with various concentrations of Sm 3+ doping; R vs dose behavior at different energies up to 2000 Gyair and the derivation of the detector calibration curves; the stability of the Sm-doped plates after they have been exposed; the instrumental limits of the present measurement technique.
Global demand for renewable and sustainable energy is increasing, and one of the most common biofuels is ethanol. Most ethanol is produced by Saccharomyces cerevisiae (yeast) fermentation of either crops rich in sucrose (e.g., sugar cane and sugar beet) or starch-rich crops (e.g., corn and starchy grains). Ethanol produced from these sources is termed a first-generation biofuel. Yeast fermentation can yield a range of additional valuable co-products that accumulate during primary fermentation (e.g., protein concentrates, water soluble metabolites, fusel alcohols, and industrial enzymes). Distillers’ solubles is a liquid co-product that can be used in animal feed or as a resource for recovery of valuable materials. In some processes it is preferred that this fraction is modified by a second fermentation with another fermentation organism (e.g., lactic acid bacteria). Such two stage fermentations can produce valuable compounds, such as 1,3-propanediol, organic acids, and bacteriocins. The use of lactic acid bacteria can also lead to the aggregation of stillage proteins and enable protein aggregation into concentrates. Once concentrated, the protein has utility as a high-protein feed ingredient. After separation of protein concentrates the remaining solution is a potential source of several known small molecules. The purpose of this review is to provide policy makers, bioethanol producers, and researchers insight into additional added-value products that can be recovered from ethanol beers. Novel products may be isolated during or after distillation. The ability to isolate and purify these compounds can provide substantial additional revenue for biofuel manufacturers through the development of marketable co-products.
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