Germination of three wheat varieties under equipotential levels of matric [vm] and osmotic [vs] stress

Choice of a crop plant to be suitable for cultivation in desert areas must be within some considerations. Desert areas are generally characterized by: [I] lack of water, [2] climatic extremes, [3] several wide deficiencies in nutrient elements, [4] salinity and ion toxicity problems and [5] interaction between one or more of such previous factors. In this work, the response of three wheat varieties [Sids 1, Sakha 93 and Glza 168] to major environmental hazards existing in desert habitats is accounted for. Besides, the combined effects of temperature, matric or osmotic water potentials under different temperatures on different germination characteristics are studied. The study is concerned with both the germination stage and the early seedling stage to ensure success of the vegetative growth later. In most cases, temperature as a single factor had the dominant effect on germination characteristics

Carbon dioxide reforming of methane on Ni/CaO-AI2O3 catalysts

NiO/AI2O3 and NiO/CaO-AI2O3 samples were prepared and calcined at 700-900°C. Characterization of these samples was made using X-ray diffraction, low temperature nitrogen adsorption, thermal programmed reduction [TPR] and chemisorption of hydrogen at 700°C. The samples were reduced and the initial catalytic methane reforming activities were determined at 700°C. The crystalline phases in each catalyst and their domination as well as textural properties of the catalysts depend on the chemical composition and calcination temperatures. The thermal programmed desorption profiles and the chemisorption of hydrogen depend on the chemical composition of the catalysts and their calcinations temperature. Hydrogen chemisorption allowed the determination of important catalytic parameters which play dominant roles in determining the initial activity of these catalysts toward methane reforming to synthesis gas by carbon dioxide at 700°C

Factors affecting aromatization functionality of n-heptane onto Cr[2]O[3]-Al[2]O[3] catalysts doped with K[2]O

CHROMIA/ALUMINA catalysts containing 2, 4, 8, 16 and 32 mol% Cr[2] O[3]. were prepared using the co-precipitation technique. Doping of the precipitated gels with 2 mol% K[2]O was made prior to calcinations at 500, 700 and 900 [degree sign] C. The structures of the calcinations products were determined from their XRD patterns and their textural properties were determined from the adsorption of nitrogen at 77 K. The dehydrocyclization of n-heptane was carried out at 520-580[degree sign] C. using helium as a gas carrier at a rate of 20-60 ml/min, in a pulse micro-reactor directly attached to a flame ionization detector. Samples containing 2 or 4 mol% Cr[2]O[3] did not show any crystalizied chromia phase, whereas those containing higher Cr[2]O[3] content showed gamma- and/or alpha- Cr[2]O[3] depending on their chromia content and calcination temperature. The surface area decreased and the pore size increased with increase of chromia content and with the rise of the calcinations temperature. Chromia/alumina catalysts calcined at 700 [degree sign] C exhibited the highest dehydrocyclization activities compared with the corresponding catalysts calcined either at 500 at 900 [degree sign] C. The conversion of n-heptane proceeded mainly via dehydrocyclization to toluene [major] and benzene [minor], with very low yield of cracking products of C[5]-naphthenes

study on using a local clay in treatment of aqueous oil spill

Aswan clay which is used in ceramic and cement industries in Egypt, its untreated as well as its thermally and chemically treated forms were employed in studying the sorption of petroleum oil from oil contaminated water at different conditions, such as pH, temperature, loading weight and some anions and cations concentrations. Thermal and chemical treatments were studied to demonstrate the role of non-crystalline and crystalline oxide contaminants on the oil adsorption efficiency