[en] The phase diagrams have been determined by isotherm method. The main obtained results which concern the influence of low quantity of an ionic surfactant on the phase diagrams are as follows: vast and stabilisation of iso trope zone in the system studied. the structural study of the water(C sup 1 sup 2 O sup 6 + 1.5% DSD) decan system shows that the crystalline zones are constituted with lamellar, cubic and direct hexagonal structures at 30 sup o sup . the structural parameters are determined by x-ray diffraction with small angles technique. The study of different zones allows to explain the conformational evolution of chain surfactant. (author)

[en] The present work deals-for environmental importance with the estimation of radioelement contents ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K in non fertilized soil, fertilized soil (crops), fertilized soil (vegetables) and samples from the bottoms of the local drainage systems collected from four sites (Govern orates) of egyptian delta. This work therefore aims at assessing eventual concentration and build up of the natural-radioactivity in the Egyptian soil treated by the locally produced single superphosphate fertilizer and phosphogypsum. A total number (42) of samples were collected from the following sites (Govern orates); 1) El-Qalyobia (Shebin El-Qanater and Abu-Zaabal); 2) El-Sharqia (Inshas and Minia El-kamh); 3) El-Dakahlia (El-Mansoura); and 4) El-Menoufia (Tala). From each locality two samples of non-fertilized soil, two samples of non-fertilized soil, two samples of fertilized soil (crops), two samples of fertilized soil (vegetables), and sample the drainage system were obtained.

[en] The effects of 20% increase of UVB on growth and yield of alfalfa (Medicago Sativa L.) and two cultivars of soybean (Glycine Max (L.) Mer) under field conditions have been investigated. The increase of UVB dose ranged between 1.746 and 7.112 J/cm₂ during experiment. The results showed that soybean yield decrease by 16% and 31% in A. 3803 and A. 2522 cultivars respectively, under UVB exposure. The dry weight and leaf area were sensitive in the A. 3803 cultivar, while they were tolerant in the A. 2522 cultivar. Alfalfa response to UVB varied during the different stages of growth, whereas the yield was 12% less in the exposed plants. (author). 21 refs., 17 tabs

[en] The report describes a preliminary study that led to explore the possibility of preserving and extending the storage life of walnut and pistachio nut by gamma radiation. Syrian walnut and pistachio nut were irradiated in a Gamma cell (dose rate 0.08 kGy/min). Radiation doses used were 0.50 and 1.00 kGy and the samples were stored at room temperature (25 to 30 Centigrade) after packaging in polyethylene pouches. Fungi infestation was determined before and after gamma radiation treatment. A radiation dose of 1.00 kGy completely inhibited fungi infestation. The present study has, therefore, been conducted to investigate the effects of gamma radiation on the Biochemical properties of walnut and pistachio nut just after irradiation (first phase). Chemical analyses have shown the phosphorus and total proteins value decrease at 0.50 and 1.00 kGy and some significant changes were observed in carbohydrates. A slight decrease in the amount of converted sugars was also observed. Fats in walnut are less vulnerable to gamma radiation than pistachio nut due certainly to the high amount in unsaturated oleic and linoleic acids. In conclusion the effect of gamma radiation on walnut and pantheistic appears nutritionally significant in pistachio nut and less in walnut. More investigations are necessary after a long time of storage to prove their intact nutritional quality and eventually their good digestibility. (author). 6 refs., 6 figs., 22 tabs

[en] This developed spectrophotometric method is helpful to determine and control the total aromatic contents in kerosene, during the treatment process of kerosene with conc. H sup 2 SO sup 4 and P sup 2 O sup 5 to remove aromatics, which have negative effect on the solvent extraction coefficient KD of uranium from the Syrian phosphoric acid, where kerosene is used as diluent. this method is rapid according to others, and simply, using the standard curve prepared by the separated aromatics from the Syrian kerosene, A =f (C) at 272 nm, we can calculate the aromatic contents in the known samples. (author). 24 Refs., 5 Figs

[en] The growth absorbency of carbonyl and carboxyl groups was used to study the effect of radiation stabilizer and improving the properties of the irradiated of polypropylene using IR spectroscopy. the result indicates that the linearity of absorbency depends on the absorbed dose in the case of c = O and O-H groups. Also the growth rate of absorbency is decreased as the percentage of stabilizer is increased, this predominate that the stabilizer plays as formation inhibitor of these groups during and post irradiation. (author).5 Refs., 2 Figs., 3 Tabs

[en] Wheat and broad beans were exposed, under field conditions, to a daily UVB of 20 % above the ambient UVB. The plant height, tiller number, number of flowers, spikletes, dry weight and leaf area in both species showed positive responses to UVB treatment. At harvest, the seeds weight of broad beans was virtually equal in exposed and unexposed plants. In wheat, seeds yield increased significantly by 15 %. In conclusion, broad beans can be considered as a tolerant cultivar to enhanced UVB, while wheat is more tolerant. (Author). 17 Tabs. 36 Refs

[en] The two important initial steps of photosynthesis-electron transfer and energy transfer occur with great speed and efficiency. New techniques in laser optics and genetic engineering age helping us to understand why. (author). 24 refs. 8 figs

[en] Thermonuclear fusion represents a practically inexhaustible source of energy. Bringing it under control is one of the next century's challenges. This general paper reviews today's situation, difficulties encountered and next steps. 10 refs. 7 figs

[en] News Agencies reported, on 9/November 1991, that the fusion reactor JET (Joint European Torus) in Abdington near Oxford, has succeeded in achieving fusion lasting for two seconds and giving capacity of 2 MW, and it will stop in February 1992 for making some modification aiming at improving the separation of plasma to restart from 1994 with the mixture of 50-50 tritium and deuterium in order to enter what is called 'the Break-Even' more effectively. It has succeeded against its major competitors, the Americans, Japanese and Russians. So, what is the fusion? And what is the value of this historical success on the way of getting the clean fusion power for world's prosperity for millions of years? These questions are asked by almost all people and this article will answer them in brief. (author). 4 refs., 5 figs