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Storage Process (storage + process)
Selected AbstractsWettability alteration of caprock minerals by carbon dioxideGEOFLUIDS (ELECTRONIC), Issue 2 2007P. CHIQUET Abstract One of the critical factors that control the efficiency of CO2 geological storage process in aquifers and hydrocarbon reservoirs is the capillary-sealing potential of the caprock. This potential can be expressed in terms of the maximum reservoir overpressure that the brine-saturated caprock can sustain, i.e. of the CO2 capillary entry pressure. It is controlled by the brine/CO2 interfacial tension, the water-wettability of caprock minerals, and the pore size distribution within the caprock. By means of contact angle measurements, experimental evidence was obtained showing that the water-wettability of mica and quartz is altered in the presence of CO2 under pressures typical of geological storage conditions. The alteration is more pronounced in the case of mica. Both minerals are representative of shaly caprocks and are strongly water-wet in the presence of hydrocarbons. A careful analysis of the available literature data on breakthrough pressure measurements in caprock samples confirms the existence of a wettability alteration by dense CO2, both in shaly and in evaporitic caprocks. The consequences of this effect on the maximum CO2 storage pressure and on CO2 storage capacity in the underground reservoir are discussed. For hydrocarbon reservoirs that were initially close to capillary leakage, the maximum allowable CO2 storage pressure is only a fraction of the initial reservoir pressure. [source] Mating biology of the leaf-cutting ants Atta colombica and A. cephalotesJOURNAL OF MORPHOLOGY, Issue 10 2006Boris Baer Abstract Copulation behavior has often been shaped by sexually selected sperm competition or cryptic female choice. However, manipulation of previously deposited ejaculates is unknown in the social Hymenoptera and the degree to which sperm competes after insemination or is actively selected by females has remained ambiguous. We studied the mating process in the leaf-cutting ants Atta colombica and A. cephalotes, which belong to one of the few derived social insect lineages where obligate multiple mating has evolved. As copulations often occur at night and in remote places, direct observations were impossible, so we had to reconstruct the sequential copulation events by morphological analysis of the male and female genitalia and by tracking the process of sperm transfer and sperm storage. We show that Atta male genitalia have two external rows of spiny teeth, which fit into a specialized pouch organ in the female sexual tract. Reconstruction of the sperm storage process indicated that sperm is transferred to the spermatheca during or immediately after ejaculation and without being mixed with sperm and seminal fluids from other males. A convergent mechanism of direct sperm transfer to the spermatheca of queens is known from two species of dwarf honeybees. Direct sperm transfer may restrict female control over the sperm storage process and the number of males that contribute to the stored sperm. J. Morphol. © 2006 Wiley-Liss, Inc. [source] A new approach for modelling simultaneous storage and growth processes for activated sludge systems under aerobic conditionsBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2005Gürkan Sin Abstract By critically evaluating previous models, a new mechanistic model is developed to describe simultaneous storage and growth processes occurring in activated sludge systems under aerobic conditions. Identifiability was considered an important criterion during the model development since it among others helps to increase the realiability and applicability of models to full-scale WWTPs. A second order model was proposed for description of the degradation of the storage products under famine conditions. The model is successfully calibrated by only using OUR data obtained from batch experiments. Calibrations were performed with biomass from full-scale WWTPs in Belgium and Spain. Predictions of the calibrated model were successfully confirmed using off-line PHB measurements, supporting the validity of the model. An iterative experimental design procedure was successfully applied and found to remarkably improve the parameter estimation accuracy for the growth on storage parameters K1 and K2, which used to have large confidence intervals when using standard experiments. The estimated biomass growth yield on substrate (0.58 mgCOD/mgCOD) is quite close to the theoretically expected range for heterotrophic growth. This became possible by properly accounting for the storage process. Moreover, the maximum growth rate was predicted in the range 0.7,1.3 per day. This range, albeit quite lower than the values reported for the growth-based ASM models, is believed to be more realistic. Finally, the new model is expected to better and more mechanistically describe simultaneous storage and growth activities of activated sludge systems and as such could contribute to improved design, operation and control of those systems. © 2005 Wiley Periodicals, inc. [source] Understanding consumers' perspectives on food labelling in IndiaINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 6 2009Jabir Ali Abstract This study aims at identifying the factors influencing consumers' perception on food labelling and its impact on food purchase decision making, through personal interviews of 631 respondents using a structured questionnaire. To analyse the consumers' perceptions on food labelling, factor analysis has been carried out to identify the underlying dimensions among a set of food labelling attributes using the principal component analysis. Based on factor analysis, four sets of components/factors have emerged, that is, (i) serving method; (ii) quality and nutrition; (iii) production and storage; and (iv) product identification, which explain 66.271% of the variance. Logit regression analysis indicates that among the socio-demographic indicators, the estimated coefficients for gender, education, income and location of residence are statistically significant. Similarly, information on quality and nutrition, production and storage processes, and basic information of the product is found to be significant, implying that these factors are more likely to influence the use of food labels in making informed purchase decisions by the consumers. The findings of the study give practical insights on food labelling issues for the food processors and policy makers. [source] | ||||||||||