Cropping Structures Adjustments Under Water Limitations in the Egyptian Agriculture

Using programming methods, the two models of cropping structures suggested by the study were remarkably different. The first model considered water availability levels, while the second tried to optimize its use. As such, some cash crops were excluded from the second model as water extensive users, such as some kinds of fruits. Hence, the second type models expected net revenues and benefit-cost ratios dropped to nearly one-third the corresponding estimates of the first type, and about 10-20% higher than those of the actual cropping structures in average. Accordingly, encouraging farmers to adopt cropping patterns of rational water use would be in vain unless fortified by taxation tools and guidance toward efficient methods of cost reduction and/or yields promotion.Crop Production/Industries,

Responses of Egyptian Food Crops Producers to New Economic Policies: Cases of Wheat and Rice

The formerly neglected wheat production is recovering under policies of economic reform and liberalization. The most effective factors are the continuous price raises and the relatively low production costs which should continue, along with attempts to improve yields and reduce costs, if to avoid imports re-expansion. As for rice, its production expansion potentials are constrained by water limitations. However, the ongoing price increases may motivate attempts to reduce both production costs and post-harvest enormous losses. Exports may be promoted as such, hardly threatening satisfaction of domestic needs, at least in the foreseen future.Crop Production/Industries,

Catalytic-Dielectric Barrier Discharge Plasma Reactor For Methane and Carbon Dioxide Conversion

A catalytic - DBD plasma reactor was designed and developed for co-generation of synthesis gas and C2+ hydrocarbons from methane. A hybrid Artificial Neural Network - Genetic Algorithm (ANN-GA) was developed to model, simulate and optimize the reactor. Effects of CH4/CO2 feed ratio, total feed flow rate, discharge voltage and reactor wall temperature on the performance of catalytic DBD plasma reactor was explored. The Pareto optimal solutions and corresponding optimal operating parameters ranges based on multi-objectives can be suggested for catalytic DBD plasma reactor owing to two cases, i.e. simultaneous maximization of CH4 conversion and C2+ selectivity, and H2 selectivity and H2/CO ratio. It can be concluded that the hybrid catalytic DBD plasma reactor is potential for co-generation of synthesis gas and higher hydrocarbons from methane and carbon dioxide and showed better than the conventional fixed bed reactor with respect to CH4 conversion, C2+ yield and H2 selectivity for CO2 OCM process

Co-Generation of C2 Hydrocarbons and Synthesis Gases from Methane and Carbon Dioxide: a Thermodynamic Analysis

This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temperature, and system pressure on equilibrium composition, conversion, selectivity and yield were studied. In addition, carbon and no carbon formation regions were also considered at various reaction temperatures and CO2/CH4 feed ratios in the reaction system at equilibrium. It was found that the reaction temperature above 1100 K and CO2/CH4 ratio=1 were favourable for synthesis gas production with H2/CO ratio unity, while carbon dioxide oxidative coupling of methane (CO2 OCM) reaction to produce ethane and ethylene is less favourable thermodynamically. Numerical results indicated that the no carbon formation region was at temperatures above 1000 K and CO2/CH4 ratio larger than

A scattering theory of ultrarelativistic solitons

We construct a perturbative framework for understanding the collision of solitons (more precisely, solitary waves) in relativistic scalar field theories. Our perturbative framework is based on the suppression of the space-time interaction area proportional to $1/(\gamma v)$, where $v$ is the relative velocity of an incoming solitary wave and $\gamma = 1/\sqrt{1-v^2} \gg 1$. We calculate the leading order results for collisions of (1+1) dimensional kinks in periodic potentials, and provide explicit, closed form expressions for the phase shift and the velocity change after the collisions. We find excellent agreement between our results and detailed numerical simulations. Crucially, our perturbation series is controlled by a kinematic parameter, and hence not restricted to small deviations around integrable cases such as the Sine-Gordon model.Comment: v3: 43 pages, 10 figures, references added, matches version accepted for publication in PR

Methane-Carbon Dioxide: Conversions to Syngas and Hydrocarbons

This monograph describes the new innovation that has recently been developed for the CH4-CO2 conversions process. Optimization of CO2 reforming of methane to synthesis gas with the help of experimental design, empirical modeling and ANN modeling are developed for CORM in presence of oxygen. An overview on dynamic equilibrium analysis has shown that an increase of sweep factors induced more significant enhancement hydrogen permeation than permselective area. The NiO/CeO2 catalyst showed potential as catalyst for the CORM. The application of a hybrid catalytic DBD plasma reactor has the potential for the co-generation of C2+ hydrocarbons and synthesis gases from methane and carbon dioxide. Carbon dioxide as co-feed has important effects on the carbon suppression. It can be concluded that three factors, i.e. CH4/CO2 feed ratio, total feed flow rate, and discharge voltage, in the DBD plasma reactor system have significant effects on the reactor performance. The hybrid catalytic DBD plasma reactor is more suitable for CO2 OCM process than the conventional catalytic reactor over CaO-MnO/CeO2 catalyst. Further innovation and improvement of current research on CH4 and CO2 are required to increase conversion and selectivity and to commercialize the process