Optimal greenhouse gas emissions in NGCC plants integrating life cycle assessment

The optimal design of an energy-intensive process involves a compromise between costs and greenhouse gas emissions, complicated by the interaction between optimal process emissions and supply chain emissions. We propose a method that combines generic abatement cost estimates and the results of existing (LCA) life cycle assessment studies, so that supply chain emissions are properly handled during optimization. This method is illustrated for a (NGCC) natural gas combined cycle power plant model with the following design and procurement options: procurement of natural gas from low-emissions producers, fuel substitution with (SNG) synthetic natural gas from wood, and variable-rate CO₂ capture and sequestration from both the NGCC and SNG plants. Using multi-objective optimization, we show two Pareto-optimal sets with and without the proposed LCA method. The latter can then be shown to misestimate CO₂ abatement costs by a few percent, penalizing alternate fuels and energy-efficient process configurations and leading to sub-optimal design decisions with potential net losses of the order of $1/MWh. Thus, the proposed LCA method can enhance the economic analysis of emissions abatement technologies and emissions legislation in general.     

Effects of Pulsed Electric Fields on Cabernet Sauvignon Grape Berries and on the Characteristics of Wines

The treatment of Cabernet Sauvignon red grapes by pulsed electric fields (PEFs) is performed prior to vinification in order to enhance the extraction of polyphenols. PEF treatments of the longest duration and of the highest energy (E?= 0.7 kV/cm, t _PEF?=?200 ms, W?=?31 Wh/kg) changed the structure of grape skins and produced a wine that was richer in tannins (34 %), while treatment of the highest strength (E?=?4 kV/cm, t _PEF?=?1 ms, W =?4 Wh/kg) altered the visual appearance of phenolic compounds in the skins and led to greater extraction of the anthocyanins (19 %). The PEF treatments caused the depolymerization of skin tannins, improving the diffusion of these decondensed tannins which are smaller. The PEF treatment of longest duration and of the highest energy had more impact on the parietal tannins and the cell walls of the skins while treatment of the highest strength modified more the vacuolar tannins. Changes in the operating parameters of the PEF treatment (E?=?0.7 to 4 kV/cm, t _PEF?=?1 to 200 ms, W?=?4 to 31 Wh/kg) did not affect alcohol content, total acidity nor volatile acidity in finished wines compared to the values of the control wine, but seemed to cause a slight increase in pH (1–2 %).     

Putting the poorest farmers in control of disseminating improved wheat seed: a strategy to accelerate technology adoption and alleviate poverty in Bangladesh

This paper reports on a ‘bottom-up’ system of wheat seed technology transfer that was piloted in north–west Bangladesh with 45 mainly marginal (food insecure) farming families during the 2004–2005 wheat season, then scaled out to a further 545 mainly marginal, farming families during the 2006–2007 season. The system was devised following a survey which indicated that such farmers can obtain a 52% increase in wheat grain yield and extra income by switching from the old Kanchan variety to the newer, heat and disease-tolerant Shatabdi variety. The bottom-up wheat seed dissemination system involved the creation of an enabling environment which allowed poor and ultra-poor farmers to store and sell selected seed of recently-released wheat varieties that they produced in 20 decimal (0.08 ha) plots. During the pilot phase of the project in 2005, farmers produced 7, 976 kg of grain and more than 50% of this was selected as high quality seed, stored during the monsoon season and marketed to other farmers just prior to the following wheat season. This seed was sold at Tk25–30/kg and realised profits averaging Tk3,002 (€38.49; exchange rate was 78:1 in October 2005) per household. In 2007, the seed price had risen to Tk33–50/kg and a larger group of farmers produced, stored and marketed 168,800 kg of high quality wheat seed, which realised profits averaging Tk5,080, equivalent to €51 (exchange rate was 99.6:1 in October 2007), per household. This bottom up seed production and dissemination system met the wheat seed requirements of more than 1,400 neighbouring farmers in areas with a deficit of wheat seed for planting, and enabled poor and ultra-poor farmers to earn more than 50% of the income they needed to cross the local poverty line.

In situ degradability of conventional and unconventional starch sources for ruminants,and factors determining their washable fraction: methodological implications

BACKGROUND: The in situ technique (IS) is used for characterising, screening and evaluating feedstuffs in ruminants. However, it is often not adapted to the particular characteristics of feeds (i.e. kinetics of starchy feeds with a standard framework used in forage). This may lead to potential biases in the final conclusions. In two successive experiments, we evaluated the degradative characteristics of conventional (CON) and unconventional (UNC) starchy feedstuffs (ING) and factors affecting their washable fractions (WF). The suitability of IS was then assessed. RESULTS: Two well‐defined ruminal fermentation patterns (CON and UNC) were observed. The WF and insoluble washable (ISWF) fractions were affected by ING, state of presentation [WAY, fresh (F) or pre‐dried (D)], particle size (PSI) and their interactions. The UNC and F feeds had greater WF and ISWF than CON and D, respectively. Increasing PSI linearly reduced WF and its proportion of ISWF. CONCLUSION: The PSI and WAY are critical factors to consider when designing experiments for the evaluation of starchy feedstuffs for ruminants using IS. It is still very risky to propose ‘standard’ parameters as this will always depend on the particular ING evaluated. Conducting pre‐evaluation tests before implementing each research protocol could help to refine the procedure. Copyright © 2009 Society of Chemical Industry     

Fungal pretreatment of wheat straw: Effects on the biodegradability of cell walls,structural polysaccharides,lignin and phenolic acids by rumen microorganisms

Disappearance of cell wall components of untreated straw and straw treated with the ligninolytic white-rot fungi Phanerochaete chrysosporium, Dichomitus squalens and Cyathus stercoreus were determined during the course of rumen digestion of samples in nylon bags. The first fungus degraded hemicelluloses and cellulose non-selectively, adversely affecting the digestion rate of crude cell walls. Dichomitus squalens and C. stercoreus preferentially degraded hemicelluloses and lignin, affording cell wall degradation rates 1.5 times higher than in native straw. Furthermore, the extent of cell wall digestion was also significantly enhanced. Both strains improved the extent of cellulose digestion, whereas the potentially degradable xylan fraction remained unchanged. Polysaccharide digestion rates were influenced in different ways depending on the strain tested: straw degraded by C. stercoreus showed an increase in cellulose digestion rate by 50%, whereas residual arabinose units were slowly degraded. Xylan was degraded 1.8 times faster in straw decayed' by D. squalens, while cellulose digestion remained unchanged. Phanerochaete chrysosporium depressed both xylan and cellulose digestion rates. Fungal-treated lignins were solubilised in the rumen faster than in untreated straw, whereas only treatment by C. stercoreus resulted in higher lignin losses. Esterified phenolic acids were extensively degraded by all three fungi. Residual ferulic and p-coumaric acids accumulated during rumen digestion, although only the former decreased in the original straw.     

The dynamics of aroma release during consumption of candies of different structures,and relationship with temporal perception

We investigated the role of both candy texture and eating technique (melting or chewing) on the dynamics of aroma release. One novelty of this type of analysis was the simultaneous application of instrumental and sensory analysis. Four candy textures were established based on their storage modulus at 1 Hz by varying the gelatine content between 0 and 15% w/w. The invivo release of three aroma compounds was monitored using Proton Transfer Reaction Mass Spectrometry and with a trained panel of testers. The gelatine content had no significant effect on the headspace/product partition and diffusion properties of the aroma compounds. The highest invivo release for all aroma compounds was obtained with the 2% gelatine sample. Our findings indicated that aroma release was determined by interaction between the product properties and oral behaviour. Relations between the dynamics of release and perception (method of Temporal Dominance of Sensations) have been established on temporal parameters.     

Search for the optimal schedule for the oxaliplatin/5-fluorouracil association modulated or not by folinic acid: preclinical data

The combination of oxaliplatin (LOHP)-5-fluorouracil (FU)-folinic acid (FA) has provided high response rates in pretreated patients with advanced colorectal cancer that is resistant to FU-FA. However, the choice of the optimal schedule between LOHP, FU, and FA remains open. The purpose of the present study was to compare, at equivalent drug area under the curve, different schedules for the LOHP-FU +/- FA combinations on four human colorectal cancer cell lines. FU +/- FA was tested as a 2-h short exposure ("bolus"), a 118-h continuous exposure ("infusion"), or a 22-h mixed exposure ("De Gramont protocol"). LOHP was administered for 2 h before, during, or after FU +/- FA exposure. Isobologram analyses revealed that LOHP associated with FU +/- FA resulted in synergistic cytotoxic effects whatever the tested schedules (in > or = 75% of cases). For the FU-LOHP combination, cytotoxicity was significantly different according to the FU exposure type (short > mixed > continuous) and was independent of the LOHP position. In contrast, for the FU-FA-LOHP combination, neither the FU exposure type nor the LOHP position significantly influenced cytotoxicity. The presence of FA significantly enhanced the cytotoxicity of FU-LOHP (P < 0.001); this potentiation was independent of the FU exposure type and was significantly influenced by the LOHP position (LOHP after FU-FA > LOHP during FU-FA > LOHP before FU-FA). In conclusion, in contrast with the recognized superiority of continuous FU exposure over short exposure when the drug is given alone, the FU-LOHP combination is more cytotoxic when FU is given as a short exposure. This suggests the potential interest of such a schedule in the clinical setting.