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Content Decreases (content + decrease)
Selected AbstractsProduction of a Laccase and Decrease of the Phenolic Content in Canola Meal during the Growth of the Fungus Pleurotus ostreatus in Solid State Fermentation ProcessesENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2004J. Hu Abstract Solid state fermentation of canola meal was carried out with the fungus Pleurotus ostreatus DAOM 197961, which is a producer of laccase. The aim of this study was to examine the effects of moisture content, inoculum size, homogenisation of inoculum and particle size of canola meal on the growth of the fungus, the production of a laccase and the decrease of the content of sinapic acid esters (SAE) in a solid state process. The results showed that the optimum moisture content, which was varied in the media between 50% and 75%, for the growth and enzyme production was 60%. The initial rate of SAE content decrease was faster in the media with 70% and 75% moisture than in those with lower moisture levels. In the study of the effects of inoculum concentration in the range of 1.1 mg to 5.5 mg/g of the medium, it was found that larger amounts of biomass and enzyme were produced in the media with inoculum concentrations from 1.1 mg to 3.3 mg/g of the medium than in the media with a higher inoculum concentration. The final and approximately the same concentrations of SAE were reached at the same time regardless of the inoculum concentration. Considering that the fungus formed pellets under the conditions at which it was grown during the inoculum preparation, it was necessary to break them by homogenisation prior to their utilisation as an inoculum. The homogenisation was carried out during a period between 15s and 200s. Although higher biomass concentrations and enzyme activities were obtained in the media which were inoculated with the inoculum homogenised for 15s and 30s, the maximum enzyme activities and biomass concentrations were reached in the media inoculated with the inoculum, which was homogenised for 120s and 200s. The time of inoculum homogenisation did not influence the kinetics of the SAE decrease. When the effects of the particle size of canola meal on the process were studied, it was found that larger particles of the meal in the solid media were more favourable for the production of the biomass and enzyme, and for a faster decrease of the SAE content than those of smaller sizes. From the obtained results it can be concluded that the tested variables have a significant influence on the growth of the fungus Pleurotus ostreatus DAOM 197961, the production of laccase and the decrease of the SAE content in canola meal. The data could be useful for the development of a solid state process for the production of laccase and for the decrease of the phenolics content in canola meal. [source] Hydrocolloid-Lipid Coating Affect on Weight Loss, Pectin Content, and Textural Quality of Green Bell PeppersJOURNAL OF FOOD SCIENCE, Issue 4 2002F.D. Conforti ABSTRACT Three coatings containing a hydrocolloid-lipid blend combination were developed and applied to green bell peppers. Peppers were refrigerated and monitored over a 5-week period to determine pectin content and textural quality. Pectin content decrease was significantly (p < 0.05) greater in the uncoated peppers during the storage period. Weight loss also occurred in the uncoated peppers at a significantly greater rate, while respiration rates and puncture score differences were insignificant among all groups. The results indicate that the coatings were effective in maintaining quality during storage. A better procedure is recommended for puncture analysis. [source] Comparison of the effects of different virus infections on performance of three Majorcan grapevine cultivars in field conditionsANNALS OF APPLIED BIOLOGY, Issue 1 2010E. Cretazzo The effects of viruses on grape production and must quality are not fully understood. In this study, the evaluation of the impact of different virus infections on performance of the main autochthonous grapevine varieties of Mallorca (Callet, Manto Negro and Moll) was pursued. Therefore, a large number of vines were observed in field conditions over 4 years and tested by enzyme-linked immunosorbent assay for viruses listed by the international certification programmes. In each variety, some specific virus infections resulted to be more effective than the others in inducing losses in production. In Callet, yield (Y) reduction was over 20% in plants infected by Grapevine fanleaf virus (GFLV). In Moll, plants subject to more than one infection showed over 40% Y decrease. In Manto Negro, the most surprising results were obtained, because plants showed almost 40% Y reduction because of Grapevine leafroll-associated virus-1 (GLRaV-1) infection. In addition, virus infections were linked to some must quality parameter increase in Manto Negro and Moll, but in the majority of cases it was an indirect effect, because the decrease in production parameters played a predominant role by producing an important concentration effect. However, in Manto Negro, anthocyanin content decrease was directly related to GFLV infection. [source] Contribution to X-ray analysis of carbo-nitrided steel layersJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2001J. M. Sprauel The non-destructive X-ray diffraction method is used to analyse carbo-nitrided steel layers after wear testing. These measurements are carried out on the two major phases of the material, i.e. the martensite and the retained austenite. Such measurements are particularly difficult for three reasons. First, strong gradients exist across the wear track. Second, the diffraction peaks obtained for the martensite are broadened, as a result of the overlap of different reflections of the tetragonal structure. Third, the studied material is multiphase. Its major phases are martensite and austenite, but it also contains carbide and nitride clusters, which lead to incoherent scattering of X-rays. A new quantitative phase analysis method is thus proposed to define the volume fractions of these different constituents of the material. This method accounts for the evolution of the background level during wear. A micro-mechanical model is then developed to process the diffraction peak positions obtained for the martensite and the retained austenite. This model defines the `true' stress and carbon content of both phases. It also allows separation of the reflections of the martensite. The true widths of the diffraction peaks, which characterize the plastic deformation, can thus be quantified. Results for wear-test specimens show a strong plastic deformation of the retained austenite during contact fatigue. This leads to a partial transformation of this phase into martensite. In the martensite, on the contrary, the plastic deformation remains low but the carbon content decreases. This is caused by a stress-induced precipitation of carbides. [source] Assessment of potential approaches to improve Eucalyptus globulus kraft pulping yieldJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2007A. S. Santiago Abstract The main goal of this work is to study the potential approaches to improve polysaccharides retention during Eucalyptus globulus kraft pulping. The addition of anthraquinone to kraft pulping leads to the highest pulp yield while the addition of urea promotes lower depolymerization of polysaccharides (higher pulp viscosity), but does not have a significant effect on yield. The early interruption of kraft cooking followed by oxygen delignification is a reliable approach to increase pulp yield, particularly when pulping is interrupted at the end of the faster and more selective kinetic regime (bulk phase). Yield loss during oxygen delignification is considerably lower than that incurred in the last phase of kraft pulping. Pulping with OH,/HS, charge profiling, carried out with liquor injection in three different phases leads to a yield increase. However, this increase results from a lower total alkali charge applied when profiling pulping is compared to standard pulping conditions, rather than to alkali profiling. Standard kraft pulping with different active alkali (AA) charges demonstrated that this operational variable is determinant for pulp yield and viscosity. Pulping experiences with lower AA (14%) resulted in a higher and almost constant pulp viscosity and in a higher pulp yield, assigned to improved retention of both cellulose and xylan. During the last stage of pulping, cellulose content decreases, this being mainly responsible for the decrease of pulp yield, while xylan content is almost constant, a feature attributed to the peculiar structure of this E. globulus's hemicellulose. Copyright © 2007 Society of Chemical Industry [source] Li-Deficient, Off-Congruent MgO:LiNbO3 Crystals Prepared by Postgrown Li-Poor Vapor Transport Equilibration for Integrated OpticsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010De-Long Zhang Li-deficient, off-congruent Z -cut MgO:LiNbO3 (MgO:LN) crystals for integrated optics were prepared by carrying out postgrown Li-poor vapor transport equilibration (VTE) treatments on congruently grown MgO (5 mol% in melt):LiNbO3 plates at 1100°C for durations ranging from 40 to 395 h. Secondary ion mass spectrometry analysis, surface ordinary refractive index measurement, and neutron activation analysis were carried out on the VTE crystals to verify that the Mg and Nb ions did not diffuse out of the crystal during the VTE procedure and their distributions over the whole plate retain its homogeneity. The VTE duration dependence of the Li2O content reduction was determined using gravimetric method, and the crystalline phase was by powder X-ray diffraction. The results show that the Li2O content decreases with a prolonged VTE and the Li2O content reduction in the saturation regime is about 2.9 mol%. All of the VTE crystals still retain the LN phase, and Li-vacancy and NbLi are the major defects in the VTE crystal. OH absorption study reveals that the doped MgO concentration is below the photorefractive threshold for all VTE crystals. The optical absorption edge (OAE) of the VTE-treated MgO:LN was also measured as a function of the VTE duration. On the basis of the known Li2O content and measured OAE, the photon-energy fit reported previously, valid for the evaluation of Li2O content in a pure LN, is corrected for the Li-poor VTE-treated MgO:LNs. Finally, the applicability of the Li-deficient off-congruent MgO:LN crystals prepared by the Li-poor VTE method is demonstrated by characterizing the optical damage and Er diffusion properties of a single-mode Ti:MgO:Er:LiNbO3 strip waveguide fabricated on an Li-poor VTE-prepared MgO:LN crystal. [source] Borehole deformation measurements and internal structure of some rock glaciers in SwitzerlandPERMAFROST AND PERIGLACIAL PROCESSES, Issue 2 2002Lukas Arenson Abstract In order to understand the mechanical processes that influence the deformation patterns of active rock glaciers, information about local horizontal and vertical deformations as well as knowledge of the internal structure and the temperature distribution is necessary. Results from borehole deformation measurements of three sites in the Swiss Alps show that despite different internal structures, similar phenomena can be observed. In contrast to temperate glaciers, permafrost within rock glaciers has distinct shear zones where horizontal and vertical differential movements are concentrated. In addition, a reduction in volume can be caused by compressive flow due to the presence of air voids within the permafrost. The flow velocity depends on the temperature, the surface and bedrock slopes of the rock glacier, and the composition of the ice-rich frozen ground. Within degrading permafrost, the ice content decreases, the creep velocity increases and the shear zone rises towards the surface, where seasonal temperature changes and the presence of liquid water might also influence deformation. Copyright © 2002 John Wiley & Sons, Ltd. [source] Chemical and physical responses to deformation in micaceous quartzites from the Tauern Window, Eastern AlpsJOURNAL OF METAMORPHIC GEOLOGY, Issue 4 2003J. Selverstone Abstract Micaceous quartzites from a subvertical shear zone in the Tauern Window contain abundant quartz clasts derived from dismembered quartz-tourmaline veins. Bulk plane strain deformation affected these rocks at amphibolite facies conditions. Shape changes suggest net shortening of the clasts by 11,64%, with a mean value of 35%. Quartz within the clasts accommodated this strain largely via dislocation creep processes. On the high-stress flanks of the clasts, however, quartz was removed via solution mass transfer (pressure solution) processes; the resulting change in bulk composition allowed growth of porphyroblastic staurolite + chlorite ± kyanite on the clast flanks. Matrix SiO2 contents decrease from c. 83 wt% away from the clasts to 49,58% in the selvages on the clast flanks. The chemical changes are consistent with c. 70% volume loss in the high-stress zones. Calculated shortening values within the clast flanks are similar to the volume-loss estimates, and are greatly in excess of the shortening values calculated from the clasts themselves. Flow laws for dislocation creep versus pressure solution imply large strain-rate gradients and/or differential stress gradients between the matrix and the clast selvages. In a rock containing a large proportion of semirigid clasts, weakening within the clast flanks could dominate rock rheology. In our samples, however, weakening within the selvages was self limiting: (1) growth of strong staurolite porphyroblasts in the selvages protected remaining quartz from dissolution; and (2) overall flattening of the quartz clasts probably decreased the resolved shear stress on the flanks to values near those of the matrix, which would have reduced the driving force for solution-transfer creep. Extreme chemical changes nonetheless occurred over short distances. The necessity of maintaining strain compatibility may lead to significant localized dissolution in rocks containing rheologic heterogeneities, and overall weakening of the rocks may result. Solution-transfer creep may be a major process whereby weakening and strain localization occur during deep-crustal metamorphism of polymineralic rocks. [source] REE and C-O Isotopic Geochemistry of Calcites from the World-class Huize Pb-Zn Deposits, Yunnan, China: Implications for the Ore GenesisACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2010Zhilong HUANG Abstract: The world-class Huize Pb-Zn deposits of Yunnan province, in southwestern China, located in the center of the Sichuan-Yunnan-Guizhou Pb-Zn polymetallic metallogenic province, has Pb+Zn reserves of more than 5 million tons at Pb+Zn grade of higher than 25% and contains abundant associated metals, such as Ag, Ge, Cd, and Ga. The deposits are hosted in the Lower Carboniferous carbonate strata and the Permian Emeishan basalts which distributed in the northern and southwestern parts of the orefield. Calcite is the only gangue mineral in the primary ores of the deposits and can be classified into three types, namely lumpy, patch and vein calcites in accordance with their occurrence. There is not intercalated contact between calcite and ore minerals and among the three types of calcite, indicating that they are the same ore-forming age with different stages and its forming sequence is from lumpy to patch to vein calcites. This paper presents the rare earth element (REE) and C-O isotopic compositions of calcites in the Huize Pb-Zn deposits. From lumpy to patch to vein calcites, REE contents decrease as LREE/HREE ratios increase. The chondrite-normalized REE patterns of the three types of calcites are characterized by LREE-rich shaped, in which the lumpy calcite shows (La)N < (Ce)N < (Pr)N, (Nd)N with Eu/Eu* < 1, the patch calcite has (La)N < (Ce)N < (Pr)N, (Nd)N with Eu/Eu* > 1, and the vein calcite displays (La)N > (Ce)N > (Pr)N > (Nd)N with Eu/Eu* > 1. The REE geochemistry of the three types of calcite is different from those of the strata of various age and Permian Emeishan basalt exposed in the orefield. The ,13CPDB and ,18OSMOW values of the three types of calcites vary from ,3.5, to ,2.1, and 16.7, to 18.6,, respectively, falling within a small field between primary mantle and marine carbonate in the ,13CPDB vs ,18OSMOW diagram. Various lines of evidence demonstrate that the three types of calcites in the deposits are produced from the same source with different stages. The ore-forming fluids of the deposits resulted from crustal-mantle mixing processes, in which the mantle-derived fluid components might be formed from degassing of mantle or/and magmatism of the Permian Emeishan basalts, and the crustal fluid was mainly provided by carbonate strata in the orefield. The ore-forming fluids in the deposits were homogenized before mineralization, and the ore-forming environment varied from relatively reducing to oxidizing. [source] | ||||||||||||||||