Vol. 4 Issue 1
M.A. Abdulmomen, H.H. Aly and H.M.M. Mansour
Three potentials, one long range, Kratzer and two short range, Hulthen and Poschl-Teller, were used to investigate the range of validity of the perturbation method developed by Muller-Kiresten.
Eigenvalues obtained exactly for these potentials are compared with those obtained by perturbation methods. These results are discussed in the conclusion
E.M. Amin
The European silver eel (Anguilla anguilla L.) obtained from the Egyptian Lake (Burollos) gave positive results when the males were induced by a human chorionic gonadotropin hormone (HCG). Males maintained in metallic tanks, supplied with sea water (salinity 37.5 ppt) and diffused atmospheric air showed a response to hormone injections. Testes attained their nearly ripe condition after the 5th injection and full testicular ripeness and consequent spermiation were achieved after the 7th injection, in a period of 45 days. Several morphometric and biological changes occurred with increasing the successive injections.
A.E. Hagras
The effect of surface area (space) on the growth of 2 populations of an initial size of 5 and 10 female Tribolium castaneum per container in a fixed weight of wheat flour at 28 degree Celsius and 31 degrees Celsius was investigated for 9 months. Growth rates of these populations were similar to both temperatures. The population density was oscillating at 28 degree Celsius and more or less regular at 31 degrees Celsius
M.S. Al-Khalifa
The structure of the calyx region of the female reproductive system in Sitophilus granarius (L.) has been described and its possible function suggested. The Calyx region is composed of columnar epithelial cells, which are typical secretory cells that release large numbers of granules into the lumen. The results of the investigation indicate that the secretory droplets of the calyx may act as a lubricant during the passage of the egg through the egg canal. These droplets may also play a major role in the formation of the plug sealing the aperture of the hole where the eggs are laid within.
Mohamed A. Bacha and Mohamed A. Shaheen
The effect of leaf/bunch ratios (5, 7, and 9 leaves/bunch) on yield and fruit quality of Nebut Seif and Ruzeizi date palm cultivars was studied for 3 successive years. Yield and average bunch weight gradually increased with increasing leaf/bunch ratio in both cultivars. Leaf/bunch ration has a slight effect on physical quality of the fruit and significant effect on total soluble solids (TSS). Moisture content of fruit at rutab stage increased with increasing leaf/bunch ratio, through the differences between treatments were not significant.
Saad Al-Barrak
A field study utilized some soils under date palm cultivation (Phoenix dactylifera L.) in the oasis of Al-Ahsa, Saudi Arabia. Some of these soils have a mollic epipedon. The formation of this diagnostic epipedon could be attributed mainly to the frequent irrigation, natural drainage, and the addition of organic material from annual burning of weeds and other plant residues. It is, thus, suggested that these soils should not be classified as Typic Torripsamments as are the surrounding uncultivated soils. These soils best fit the criteria for Typic Haplaquolls and Typic Haplaquents which may be true of most of the oasis soils of Al-Ahsa under date palm cultivation.
M.F. Soliman
A pot experiment was conducted on calcareous soil study the interactive effects of saline irrigation water and N-P application rates on growth, yield, N and P content in grains of wheat variety Giza 157. A positive responses in plant height, number of tillers, grain yield, N and P content was obtained for the added N and/or P rates. The degree of response varied considerably from one trait to another at the variable N and P rates. On average, the reductions obtained at the optimum N and P levels due to increasing salinity were subsequently 9.4, 27.6, 18.5, 4.4 and 15.1% for the above-mentioned traits.
The interaction effect of NxP treatments was clearly pronounced on the number of tillers, grain yield and its P content. The differences between N treatments along P rates varied among the measured parameters.
Number of tillers was linearly and quadratically increased with increasing N rates under both salinity treatments. By increasing the level of salinity, number of tillers was decreased along N rates, but the degree of reduction was, however, greater at the highest N level.
Phosphorus X salinity interaction, only influenced the grain yield and its P content. Increasing salinity produced a greater reduction in yield at the higher P rates than the lower ones. A greater reduction in P content was detected between P2 and P3 due to increasing salinity.
Since the grain yield was not drastically reduced under saline treatment, it was concluded that application rates of 150 kg N/ha and 75 kg P2O5/ha were effective for increasing yield under saline and non-saline conditions
Mahmoud H. Abdel-Aziz and Mohammad Saeed
The evapotranspiration of crops is often determined from the reference evapotranspiration, ET (of alfalfa or grass) by using suitable crop coefficients. This technique can easily be adopted for computerized irrigation scheduling. To obtain crop coefficients under hot and arid conditions , some of the crops were grown in lysimeters and their ET was obtained . The ET measurements for a uniform and well watered stand of alfalfa, grown in lysimeters, were also made and the reference ET for 20 cm tall alfalfa was obtained from the record.
For most of the crops, the ET and hence the crop coefficients fall into phases in accordance with the growth stage , namely: initial, flowering and fruiting stages. The crop coefficients were found to change considerably from one stage to another, in some cases. Hence a single value of a crop coefficient is usually not suitable for the entire crop season.
Values of the ET crop coefficients are given for some crops , for better estimates of ET under hot and arid climates in general and Saudi Arabia in particular.
Abdulaziz A. El-Sulaiman, Abobakr S. Ahmed, M. Iqbal Qureshi and Mahmoud M.A. Hassan
This work presents the experimental results of the effect of field strength and temperature on the dielectric and physical properties of transformer oil sampled from EHV transformer operating for the past seven years. Aged oil was compared with fresh transformer oil and the impact of filtration and degassing on the dielectric, and physical properties are discussed. Viscosity, relative humidity and cations content are correlated with dielectric properties. Experimental studies reveal that dielectric loss index for all samples is field independent but temperature dependent and increases exponentially as the temperature is increased. Dielectric loss index provides a reliable picture of oil aging as its value increases rapidly with the age of oil. Ferric iron content is increased by large factor due to aging. Carbonyl groups and polar products could not be detected in the oil samples using GC, JR, PMR and 13C-NMR techniques of spectroscopy.
A.F. Abdul-Fath and H. Sofrata
Selection of cooling systems based upon the traditional definition of the coefficient of performance (COP) may create misleading results because it does not consider all factors affecting the selection . A multi-attribute decision analysis is necessary to differentiate between various air conditioning cooling systems for arid zones. The Kingdom of Saudi Arabia is chosen to be the case study and seven main criteria, which include twenty subcriteria are selected.
To carry out such analysis, an Interactive Fuzzy Decision Analysis Computer Package (IFDA) is used. This package utilizes verbal rating, weights for each attribute and sub attribute as Input, IFDA is based on Fuzzy Set theory. The results show that the Li Br absorption dual system is the best air conditioning cooling system to be used in Saudi Arabia and the ammonia water absorption system is the second best.