Search

ones are the most dominant in the new reclaimed areas in Egypt. The main production constraints of this type of soil are low in organic carbon, porosity, stable aggregates, water retention capacity, and biological activities. Agriculture soil should have not only a good structure but also a good structure which can persist for a long time (e.g., a structure of high quality and stability). Soil aggregates are structural units of soil, which create complex pore systems controlling gas and water storage and fluxes in soil. Formation and stability of natural soil aggregates are affected by dozens of different factors and their individual effects are hardly distinguishable. Therefore, to observe more clear the mechanisms governing their water and mechanical stability, it was found necessary to study soil aggregates. In that sence, some studies showed encouraging findings of increasing soil stable aggregates due to using different soil conditioners. The objective of this work is to assess some extracellular polysaccharides biopolymers, i.e., Dextran, Alginate, Xanthan, Pullulan, and Curdlan, which were produced in our laboratory under the most suitable production conditions, to test their effects on the physical proprerties of soil taken from Toshka region at Aswan Governorate of Egypt. Data showed that soil porosity and MWDwet values have significant differences between all treatments and control under un-leaching processes. On the Other hand, in leaching processes, significant differences between all treatments and control were observed except in some treatments that using lower ratios of Pullulan and Curdlan biopolymers (i. e. 0.4, 0.6 and 0.8%). Generally, the beneficial order of enhancement of aggregate stability was obtained with Dextran, followed by Alginate, Xanthan, Pullulan, and Curdlan.

In this paper, for the first time we introduce a new four-parameter model called the Gumbel- Pareto distribution by using the T-X method. We obtain some of its mathematical properties. Some structural properties of the new distribution are studied. The method of maximum likelihood is used for estimating the model parameters. Numerical illustration and an application to a real data set are given to show the flexibility and potentiality of the new model.

Broyden update is one of the one-rank updates which solves the unconstrained optimization problem but this update does not guarantee the positive definite and the symmetric property of Hessian matrix. In this paper the guarantee of positive definite and symmetric property for the Hessian matrix will be established by updating the vector which represents the difference between the next gradient and the current gradient of the objective function assumed to be twice continuous and differentiable .Numerical results are reported to compare the proposed method with the Broyden method under standard problems.

Three experiments for to pot ond one field experiment were carried out at Agric. Res. Station, Fac. Agric., Al-Azhar Univ. Nasr City and El-Aklag region, Kaliobia Governorate, Egypt, during 2011/2012, 2012/2013 and 2013/2014 to investigate the influence of mineral nitrogen fertilizer and biological ones i.e. Cerialen and Biogen under foliar spraying with Cysteine on the productivity of three wheat varieties (Sakha-93. Masry-1 and Banisweif). The studied treatments were recommended dose of N (75 kg N/fed., F1), recommended dose of N. fertilizer + Cysteine at the rate of 150 ppm (F2) 50% recommended dose of N fertilizer + Cerialine + Cysteine (F3) and 50% recommended dose of N fertilizer + biogen + Cysteine (F4). Complete randomized design was applied for the pot experiments, whereas split plot design was conducted for the experimental field. The results revealed that the difference between the investigated varieties due to plant height (cm) and flag leaf area (cm2) was substantial. Sakha-93 var. pronounced its superiority due to the both studied growth characters during the pot and field experiment. F2 treatment located the first order and gave the tallest wheat plants, whereas F4 treatment awarded the largest area of flag leaf, during the three experimental seasons. Yield and yield components parameters (No of grains/spike, 1000-grain weight (g), grain yield (g/plant in pots and ardab/fed. in field), straw yield (g/plant and ton/fed. in field) and biological yield (g/plant in pots and ton/fed. in field ) differed significantly between varieties. the maximum value were obtained from Sakha-93 and Masry-1, while the minimum ones associated with Baniswif variety, through the three experimental seasons. With the exception of straw yield either pot experiments or the field one, F2 and F4 treatments resulted in the heighest data for the previous yield and yield components parameters. The effect for the first order interaction (Var. x Fert.) on the studied characters differed with the characters difference (significant or non-significant) as shown from the obtained results during the three experimental seasons.

The research sought to answer several questions, the most important of which is what are the Iranian justifications for developing its nuclear program? What are the means used by the United States to deal with the Iranian nuclear program? Therefore, the research was divided into three chapters. The first chapter talked about the emergence of the Iranian nuclear program and included two sections. The first topic dealt with the Iranian nuclear program before 1979, while the second topic dealt with the program after 1979. The second chapter was titled The Motives of the Iranian Nuclear Program and included three topics. The first topic was devoted to the political motive, while the second topic focused on the economic motive, and the third topic dealt with the security and military motive. The position of the United States on the Iranian nuclear program for the period from 1945 to 1987, while the second topic dealt with the position of the United States from 1979 to 2000, and the third topic dealt with the position of the United States from 2001 to 2015.

ABSTRACT: The work included the preparation of cobalt complexes having general formula [ CoL] , where L is divalent tetradentate Schiff base ligand derived from benzyl and anthranilic acid or o-aminophenol with 1:2 molar ratio . These complexes reacted with H2O2 in the absence and in the presence of B (B= py , -pic , Pph3) at room temperature to obtain [ CoLO2 ] and [CoLBO2 ] complexes. All the prepared complexes were characterized by metal content analysis , molar conductance , spectral studies including I.R and electronic spectra as well as magnetic measurements. These studies revealed that all the complexes are non-electrolytes. The Schiff base ligands act as dibasic tetradentate ( NNOO-donor) , CoL complexes are square planar containing one unpaired electron. The electronic spectra reveals the oxidation of Co(II) to Co(III) in [CoLO2] and [CoLBO2] complexes. These complexes show μeff values related to one unpaired electron , that belongs to O2 mioety , which is supported by (υo-o) band in I.R spectra that related to O2 mioety. Hence superoxo compounds are realy recognized.

A simple and sensitive Spectrophotometric method for the determination of aniline in aqueous medium is described. The method is based on the formation of a yellow coloured azo product from the diazotisation of aniline followed by a coupling reaction with 2,6-dihydroxybenzoic acid in the presence of sodium carbonate. Absorbance of the resulting yellow azo dye is measured at 432 nrn and is stable for 1 hour at least. Beer's law is obeyed in the concentration range of 5-80|ig of aniline in a final volume of 25ml, with a molar absorptivity of 4.2xl04l.morl.cm"!, a relative error of +1.13 to+ 4.40 % and a relative standard deviation of ±0.30 to ±0.76%, depending on the concentration level. The method is successfully employed for the determination of aniline in river and waste waters.