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Bryant, Dave N.; Morris, S. Michael; Leemans, Dave; Fish, S. A.; Taylor, S.; Todd, R. W.; Logan, D.; Lee, M.; Ellis, A.; Gallagher, Joseph A. (Elsevier, July 27, 2011)[more][less]
Abstract: Dielectric spectroscopy (DS) is routinely used in yeast and mammalian fermentations to quantitatively monitor viable biomass through the inherent capacitance of live cells; however, the use of DS to monitor the enzymatic break down of lignocellulosic biomass has not been reported. The aim of the current study was to examine the application of DS in monitoring the enzymatic saccharification of high sugar perennial ryegrass (HS-PRG) fibre and to relate the data to changes in chemical composition. DS was capable of both monitoring the on-line decrease in PRG fibre capacitance (C = 580 kHz) during enzymatic hydrolysis, together with the subsequent increase in conductivity (G = 580 kHz) resulting from the production of organic acids during microbial growth. Analysis of the fibre fractions revealed >50% of HS-PRG lignocellulose had undergone enzymatic hydrolysis. These data demonstrated the utility of DS biomass probes for on-line monitoring of simultaneous saccharification and fermentation (SSF). URI: http://hdl.handle.net/2160/7757 Files in this item: 0
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Cabrita, A. R. J.; Dewhurst, Richard J.; Melo, D. S. P.; Moorby, Jon M.; Fonseca, A. J. M. (Elsevier, August 18, 2011)[more][less]
Abstract: A cyclical changeover design experiment (3-wk periods; 12-wk total) was conducted to evaluate whether improving the balance of absorbable AA would allow the feeding of less crude protein (CP) without compromising production, thereby reducing the potential environmental pollution from dairy farms. Sixteen multiparous Holstein cows were assigned to 1 of 8 dietary treatments as total mixed rations (TMR) containing [dry matter (DM) basis] 45% corn silage, 5% coarsely chopped wheat straw, and 50% concentrate mixture. The 8 treatments were formulated to differ in dietary CP (14 and 16%; DM basis) and in the balance of absorbable AA achieved by changing the main protein source (MPS) of the concentrate mixtures [replacing soybean meal (SBM) with corn byproducts (CBP), dried corn distillers grains (DDG), and some corn gluten meal], and by adding a mixture of rumen-protected Lys and Met (RPLM). Feeding lactating dairy cows corn silage-based diets with 16% CP promoted significantly higher DM intakes and milk yields, and lower feed N-use efficiency than feeding diets with 14% CP. Replacing SBM with CBP significantly increased milk yields and decreased milk fat and protein concentrations, but had no effect on the efficiency of conversion of feed N into milk N. With 16% CP diets, the addition of RPLM decreased feed N use efficiency. A significant effect was observed for the MPS × RPLM interaction on milk protein concentrations. Plasma Lys concentration was lower with diets based on CBP, and plasma Met increased with RPLM. We did not find clear benefits of RPLM in facilitating a reduction of dietary protein without loss of production. URI: http://hdl.handle.net/2160/7756 Files in this item: 0
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Valentine, John; Clifton-Brown, John; Hastings, A.; Robson, Paul; Allison, Gordon G.; Smith, P. (Blackwell Publishing, July 19, 2011)[more][less]
Abstract: This review addresses the main issues concerning anticipated demands for the use of land for food and for bioenergy. It should be possible to meet increasing demands for food using existing and new technologies although this may not be easily or cheaply accomplished. The alleviation of hunger depends on food accessibility as well as food availability. Modern civilizations also require energy. This article presents the vision for bioenergy in terms of four major gains for society: a reduction in C emissions from the substitution of fossil fuels with appropriate energy crops; a significant contribution to energy security by reductions in fossil fuel dependence, for example, to meet government targets; new options that stimulate rural and urban economic development, and reduced dependence of global agriculture on fossil fuels. This vision is likely to be best fulfilled by the use of dedicated perennial bioenergy crops. We outline a number of factors that need to be taken into account in estimating the land area available for bioenergy. In terms of provisioning services, the value of biofuels is estimated at $54.7‒$330 bn per year at a crude oil price of $100 per barrel. In terms of regulatory services, the value of carbon emissions saved is estimated at $56‒$218 bn at a carbon price of $40 per tonne. Although global government subsidies for biofuels have been estimated at $20 bn (IEA, 2010b), these are dwarfed by subsidies for fossil fuel consumption ($312 bn; IEA, 2010b) and by total agricultural support for food and commodity crops ($383.7 bn in 2009; OECD, 2010). Description: Review paper URI: http://hdl.handle.net/2160/7748 Files in this item: 0
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Robbins, Mark P.; Evans, Geraint; Valentine, John; Donnison, Iain S.; Allison, Gordon G. (Elsevier, November 20, 2011)[more][less]
Abstract: Currently, significant academic and industrial activity is focused on sourcing feed stocks from non-food biomass crops for the sustainable production of energy, power and chemical products. Crops identified as suitable for Northern Europe include Miscanthus, switchgrass (Panicum virgatum), reed canary grass (Phalaris arundinacea) and short rotation coppice willow and poplar (Salix and Populus spp.). All of these crops provide biomass that is amenable for conversion by thermochemical processes i.e. those based on heat and pressure. There are concerns that for some processes the conversion efficiency of biomass is poor compared with coal and oil due to comparatively low energy density, high moisture content, and poor storage and handling properties. Many of these parameters can be improved by pre-processing feed stock materials prior to their conversion. We examine the energy crop species that are suitable for Northern Europe; discuss the processes of combustion, gasification and pyrolysis, and explore how differences in chemical composition influence conversion efficiency. Finally, we review biomass upgrading (pelletisation, torrefaction and treatment with sub-critical (hydrothermal upgrading) and with supercritical water). URI: http://hdl.handle.net/2160/7747 Files in this item: 0
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Allison, Gordon G. (INTECH Open, April , 2011)[more][less]
http://www.intechopen.com/articles/show/title/application-of-fourier-transform-mid-infrared-spectroscopy-ftir-for-research-into-biomass-feed-stock
URI: http://hdl.handle.net/2160/7746 Files in this item: 0