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排序方式: 共有548条查询结果,搜索用时 23 毫秒
61.
Producers, retailers and other food chain actors increasingly recognize that consumer concerns for good animal welfare represent a business opportunity that could be profitably incorporated into their commercial strategies. Therefore, during the last decade, numerous trade groups (producers, processors, retailers and restaurant chains) have developed certification systems with their suppliers which include elements of animal welfare. The Welfare Quality® project has developed an integrated and standardised welfare assessment system based on twelve welfare criteria grouped into four main principles (good feeding, good housing, good health and appropriate behaviour) according to how they are experienced by animals. One of the innovations of the Welfare Quality® assessment system is that it focuses more on outcome measures (e.g. directly related to animal body condition, health aspects, injuries, behaviour, etc.). This paper has the objective to discuss the rationale behind the welfare assessment and to describe the Welfare Quality® assessment of pigs and cattle at the slaughterhouse. 相似文献
62.
Beata Kosowska Sylwia Mozia Antoni W. Morawski Barbara Grzmil Magdalena Janus Kazimierz Kaucki 《Solar Energy Materials & Solar Cells》2005,88(3):269-280
The investigation on incorporating nitrogen group into titanium dioxide in order to obtain powdered visible light-active photocatalysts is presented. The industrial hydrated amorphous titanium dioxide (TiO2·xH2O) obtained directly from sulphate technology installation was modified by heat treatment at temperatures of 100–800 °C for 4 h in an ammonia atmosphere. The photocatalysts were characterized by UV–VIS–DR and XRD techniques. The UV–VIS–DR spectra of the modified catalysts exhibited an additional maximum in the VIS region (, ) which may be due to the presence of nitrogen in TiO2 structure. On the basis of XRD analysis it can be supposed that the presence of nitrogen does not have any influence on the transformation temperature of anatase to rutile. The photocatalytic activity of the modified photocatalysts was determined on the basis of decomposition rate of phenol and azo-dye (Reactive Red 198) under visible light irradiation. The highest rate of phenol degradation was obtained for catalysts calcinated at 700 °C (6.55%), and the highest rate of dye decomposition was found for catalysts calcinated at 500 and 600 °C (ca. 40–45%). The nitrogen doping during calcination under ammonia atmosphere is a very promising way of preparation of photocatalysts which could have a practical application in water treatment system under broader solar light spectrum. 相似文献
63.
Grau BaqueroBernat Esteban Jordi-Roger Riba Antoni RiusRita Puig 《Biomass & bioenergy》2011,35(8):3687-3697
The use of straight vegetable oil (SVO) as biofuel has been recognized as a valid substitute of diesel fuel in the agricultural sector under specific circumstances. Its direct use reduces most of the chemical processes involved when converting it into biodiesel, thus lowering harmful emissions. This study presents the economic analysis of a self-supply farming model that uses rapeseed as its fuel base. This model addresses agricultural environmental concerns and can even minimize dependence on the fluctuating costs of diesel fuel. The use of SVO in agriculture can help reduce farmers’ vulnerability to fossil fuel prices. The economic evaluation of the model proposed in this study shows clear economic benefits of introducing rapeseed to the traditional crop rotation of wheat and barley. The key factors analyzed in this model are diesel fuel price, diesel fuel grants and crop aids. The current situation in Spain favors the use of diesel fuel in agriculture rather than rapeseed SVO due to an 8% profit difference. However, results show that changes in key factors slightly affect the profit margin, calculating a difference of only 3.7% for particular factor combinations. Combined environmental-friendly agriculture supporting policies are necessary to cover this slight profit difference to promote this biofuel. 相似文献
64.
Composite Ni-P-TiO2 and Ni-P-TiO2-Al layers were prepared by simultaneous electrodeposition of nickel and titanium dioxide (anatase) with an addition of Al. powder on a copper substrate from a solution in which TiO2 and Al powder were suspensed by stirring. The electrodeposition was carried out under galvanostatic conditions at a current density j = 300 mA cm–2 and temperature of 298 K. The phase composition of the layers was investigated by the X-ray diffraction method. It was found that during the electrodeposition process a spherical crystalline particle of TiO2 could be incorporated into the Ni-P phase matrix. The diffractogram of Ni-P-TiO2-Al layer shows that the layer contains crystallites of aluminium and TiO2. It means that transport of the metallic phase to the electrode is only possible when using TiO2 as its carrier. This allows to extract of aluminium in alkaline environment from the Ni-P-TiO2-Al layer and to obtain the active surface. 相似文献
65.
MiquelA. Perics David Castellnou Israel Rodríguez Antoni Riera Lluís Sol 《Advanced Synthesis \u0026amp; Catalysis》2003,345(12):1305-1313
A functional analogue of (R)‐2‐piperidino‐1,1,2‐triphenylethanol was synthesized and anchored to different polymeric supports by a position remote from the active region. This strategy, leading to what we call a tail‐tied ligand, allows for the achievement of the optimal transition state geometry in the catalytic process. The catalytic activity of the resulting heterogenized ligands was investigated by online FTIR analysis. The optimum polymer was assayed in the addition reaction of diethylzinc to a large family of aldehydes rendering essentially intact high catalytic activity and enantioselectivity compared to its homogeneous counterpart. 相似文献
66.
Antoni Femenia James A Robertson Keith W Waldron Robert R Selvendran 《Journal of the science of food and agriculture》1998,77(4):511-518
By-products arising from vegetable processing activities have been assessed in relation to their potential application as sources of dietary fibre supplements in refined foods. Sources used were fresh cauliflower, globe artichoke and chicory witloof. Non-starch polysaccharide (NSP) content and composition of selected parts of each plant source have been measured from alcohol insoluble residues (AIR) and by fibre analysis, complemented by methylation analysis to characterise structural features of component polysaccharides. Results indicate that cauliflower upper stem NSP was similar to the floret (∽25 g kg−1 fresh weight) and each was rich in pectic polysaccharides. Cauliflower lower stem was enriched in NSP (∽66 g kg−1) due mainly to cellulose and xylan deposition, which resulted in a proportionate decrease in pectic polysaccharides. Artichoke stem (∽38 g NSP kg−1) was similar to the receptacle (∽34 g NSP kg−1) but bracts were heavily lignified. Chicory root and leaf bud were each rich in pectic polysaccharides but NSP content was much higher in the root (∽46 g kg−1) than the leaf (∽8 g kg−1). Results indicate that processing by-products, eg cauliflower upper stem, artichoke stem and chicory root, could prove useful as sources of pectic polysaccharide-rich supplements. However, polysaccharide composition and glycosidic linkage pattern also identified important structural differences between sources. The importance of ‘fibre type’ when considering development of food supplements is discussed. © 1998 SCI. 相似文献
67.
D. Magimai Antoni Raj A. Dhayal Raj A. Albert Irudayaraj 《Journal of Materials Science: Materials in Electronics》2014,25(3):1441-1445
The oxides of transition metals are an important class of semiconductors, which have applications in electronics, magnetic storage media, solar applications and catalysis. Among them, CuO has attracted much attention due to its widespread applications. In this paper, a facile synthesis of rice shaped CuO nanostructures have been prepared by reflux method for battery application using Copper nitrate and ammonia as precursors. Samples were prepared at three different reaction timings namely 6, 12 and 24 h. The as-prepared samples were calcinated at 400 °C to ensure the formation of copper oxide. The final products were subjected to X-ray diffraction, scanning electron microscopy, FT-IR and UV–Vis spectroscopy in order to study the effect of reaction time on the properties of the prepared copper oxide nanostructures. It is found that at controlled reaction time rice shaped CuO nanostructures are obtained. Cyclic voltammogram was recorded to understand the electrocatalytic behaviors of the rice shaped CuO sample prepared under optimized condition. 相似文献
68.
Pons Jaume; Planas Antoni; Querol Enrique 《Protein engineering, design & selection : PEDS》1995,8(9):939-945
Bacillus 1,3-1,4-ß-glucanases possess a highly conserveddisulfide bridge connecting a ß-strand with a solventexposedloop lying on top of the extended binding site cleft The contributionof the disulfide bond and of both individual cysteines (Cys61and Cys90) in the Bacillus licheniformis enzyme to stabilityand activity has been evaluated by protein engineering methods.Reduction of the disulfide bond has no effect on kinetic parameters,has only a minor effect on the activity-temperature profileat high temperatures, and destabilizes the protein by less than0.7 kcal/mol as measured by equilibrium urea denatu ration at37°C. Replacing either of the Cys residues with Ala destabilizesthe protein and lowers the specific activity. C90A retains 70%of wild-type (wt) activity (in terms of Vmax), whereas C61Aand the double mutant C61AC90A have 10% of wt Vmax. Alarger change in free energy of unfolding is seen by equilibriumurea denaturation for the C61A mutation (loop residue, 3.2 kcal/molrelative to reduced wt) as compared with the C90A mutation (ß-strandresidue, 1.8 kcal/mol relative to reduced wt), while the doublemutant C61AC90A is 0.8 kcal/mol less stable than thesingle C61A mutant. The effects on stability are interpretedas a result of the change in hydrophobic packing that occursupon removal of the sulfur atoms in the Cys to Ala mutations 相似文献
69.
Lactobacillus delbrueckii subsp lactis strain CIDCA 133 inhibits nitrate reductase activity of Escherichia coli 总被引:3,自引:0,他引:3
The aim of the present work was to investigate the effect of strain CIDCA 133 on the nitrate reductase activity of a non-pathogenic Escherichia coli strain. Suspensions containing different ratios of the strains under study were coincubated in MRS or MRS without glucose. In some experiments lactobacilli were killed by UV treatment. The nitrate reductase activity was determined by using a diazotization reaction for nitrite. Presence of live lactobacilli leads to a dose-response diminution in the specific nitrate reductase of E. coli even when no acidification occurred. Killing of lactobacilli by UV treatment completely abolished the anti-nitrate reductase effect. In addition, the effect was only partially observed with filtered spent culture supernatants of lactobacilli. Lactobacillus delbrueckii subsp lactis strain CIDCA 133 is able to antagonize the nitrate reductase activity of E. coli. This effect is neither due to a diminution of the viability of E. coli nor is depending on the acidification of the medium by the lactobacilli. Viability is needed for maximal anti-nitrate reductase activity. Modulation of undesirable enzymatic activities of intestinal microorganisms by means of selected microorganisms constitutes a further insight on the mechanisms by which probiotics lead to beneficial effects. Administration of probiotic strains able to modulate microbial intestinal activities could lead to a protection of the host against harmful effects of some members of the intestinal microflora. 相似文献
70.
Antoni Munar Andreas Sandström Shi Tang Ludvig Edman 《Advanced functional materials》2012,22(7):1511-1517
A combination of impedance spectroscopy, device characterization, and modeling is used to pinpoint key processes in the operation of polymer light‐emitting electrochemical cells (LECs). At low applied voltage, electric double layers with a thickness of ≈2–3 nm are shown to exist at the electrode interfaces. At voltages exceeding the bandgap potential of the conjugated polymer (V ≥ 2.5 V for superyellow), a light‐emitting p–n junction forms in situ, with a steady‐state structure that is found to depend strongly on the applied voltage. This is exemplified by that the effective p–n junction thickness (dpn) for a device with an interelectrode gap of 90 nm decreases from ≈23 nm at 2.5 V to ≈6 nm at 3.9 V. The current increases with decreasing dpn in a concerted manner, while the brightness reaches its peak at V = 3.4 V when dpn ≈ 10 nm. The existence of an optimum dpn for high brightness in LECs is attributed to an offset between an increase in the exciton formation rate with decreasing dpn, due to an increasing current, and a simultaneous decrease in the exciton radiative decay rate, when an increasing fraction of excitons diffuses away from the p–n junction into the surrounding non‐radiative doping regions. 相似文献