Vol. 9 Issue 2
Abdallah M. Al-Rashed and Neyamat Zaheer
Let ∆ be the Unit disk |z|≤1 in the complex plane C. The well known Bernstein's theorem on the bounds of the derivative of an nth degree polynomial f: C ---> C states that if f(∆) C ∆ then |f'(∆)|≤ n (i.e. |f'(z)|≤ n for |z|≤1). This result was generalized by Szego and sharpened by Lax under an additional condition. Here, we obtain quite a general theorem that deduces all these results as corollaries and· furnishes a chain of interesting new results, some of which offer more general versions (sometimes sharper estimates for |f'(z)|) of the theorems of Bernstein, Szego, and Lax. In fact, we present a unified approach to the basic nature of the problem and its solution underlying Bernstein's theorem and other related Bernstein-type results.
Khalil I. Al-Mughrabi and Ibrahim K. Nazer
Chemical analysis of King Abdallah Canal (KAC) water in the Jordan Valley (JY) was conducted for collected samples from ten different sites along the KAC. Water analysis include parameters such as pH, electrical conductivity (E.C.), and major anions and cations.
The chemical stability of dimethoate was studied at different water pH values. Four different treatments were used to study the stability of dimethoate. These treatments were canal water (pH = 8.44), distilled water, phosphoric acid - treated canal water (pH = 6.00), and propionic acid - treated canal water (ph = 6.00). Spray solutions samples were allowed to stand for 1,4 and 24 hrs before extraction. Gas liquid chromatographic (OLC) method was performed in the determination of dimethoate in water samples. Canal water samples caused the highest % of hydrolysis for dimethoate after 24 hrs from treatment, while losses were much lower in distilled water. Phosphoric acid - treated canal water showed almost negligible % of hydrolysis during 24 hrs, while propionic acid - treated canal water was much less efficient compared to distilled water and phosphoric acid - treated canal water.
Ibrahim A. AI-Kadi
A new rain rate map suitable for radio wave propagation studies and radio link design in Saudi Arabia is presented. The map is developed utilizing 18-year rainfall data for all regions in Saudi Arabia (actual rainfall measurements in 101 recording stations). The new map is compatible with the global CCIR rain climatic zones. Such a map is needed where centimetric and millimetric wave radio communication systems arc to he installed.
A.A. Mohammed and S.A. Nour
Specimens of the system “U-Nd-O" were prepared by solid reaction containing different Nd-concentrations. The resulting compounds were phase analysed using X-ray powder diffractometry, and a single-phase region with fluorite structure was observed in the Nd2O3, molar concentration range (33% - 63%). The lattice parameter also behaved in a manner confirming a preliminary phase diagram deduced earlier O/U ratios, determined by standard polarographic techniques, exhibited an oxidation stability of the resulting fluorite structure in the concentration region up to 63 mol% Nd2O3, suggesting that the fluorite structure observed in the high Nd2O3, region is different. Room temperature magnetic susceptibilities of individual compounds exhibited clear regional distinctions which support the suggested phase diagram The observed behaviour is discussed in terms of the effect of the Nd-ion on the oxidation state of the U-ion.
S.A. Younis, H.A. Shahatha, F.I. Al-Rawi and E.G. Hagop
Soaking-drying treatment of rice seeds (Oryza sativa L. var. Amber 33) significantly reduced the loss of vigour and viability under accelerated ageing conditions. This was with 12 month seed. The beneficial effects of this pretreatment were associated with significant increase in protease activity, which may reneet a curative effect. Thus, the age-induced damage to the cellular components could be enzymatically repaired. However, similar pretreatment of fresh, 2-month-old seed caused deleterious effect as compared to untreated seeds
Y.Z. El-Shafei and A.M. Al-Darby
An infiltration experiment was carried out on columns of a loam soil (Fluventic Camborthids) packed to five bulk densities. Equations based on physical parameters were derived to compute the advance of the wetting front and cumulative infiltration. These parameters were bulk density (Db), initial moisture content (θo), the moisture content in the transmission zone (θt), the hydraulic conductivity of the transmission zone (KT), and the matric suction head of the wetting front (ψ) . The equations mainly utilized Darcy's law and the physical characteristics of the transmission and the wetting front zones. The derived equations have been found to be in good agreement with the experimental results and also with empirical power type equations which often used for practical purposes. The empirical equations were taken into account Db, θo, and θt. A relation between an empirical constant (A) and bulk density (Db) was found. This may be used as tentative guide for predicting the infiltration capacity of loam soils which are subjected to seasonal volume changes as result of cultivation and heavy agricultural machinery.
M.O.A. Warrag
In this study the tomato cultivars Pearson Al-improved, Marmande and VFN-8 were grown at three planting dates , to identify the reproductive attributes and abnormalities implicated in the low yield of field-grown tomatoes, encountered in Qassim, Saudi Arabia , during the winter season. The planting dates started in September, 1987, with monthly intervals, and then repeated the following year. In all cvs, the number of nowers per plant decreased slightly, whereas fruit set percentage and average fruit weight decreased substantially, resulting in a significantly low yield, as planting date was delayed. The failure of fruit set and perhaps the reduction in average fruit weight could be ascribed to inefficient pollination during the first two plantings, in addition to lack of fertilization during the last planting. Inefficient pollination was due to poor pollen dehiscence and due to both poor pollen dehiscence and low pollen production during the first two and the last plantings, respectively, whereas the lack of fertilization was due to low pollen viability and female sterility. Cv Marmande outperformed the other evs, followed hy Pearson AI-improved, during late plantings.
M.O. Basalah
Effects of six salinity levels on seed germination, length, fresh and dry weights, carbohydrate contents and a-amylase activity of squash seedlings were studied. Salinity progressively decreased the percentage of germination. The length, and the fresh and dry weights of root and shoot increased as the salinity level increased up to 8 m mhos/cm EC, indicating that squash can tolerate quite a high level of salinity at seedling stage. The soluble and insoluble carbohydrate contents and a-amylase activity were also affected by salinity.
A.A. Al-Mulla, H.O. Burhan, Y.M. Makki and M.D. Abo-Rady
Field experiments were conducted at two locations and in two seasons, 1985-86 and 1986-87, to study the effect of split application of nitrogen fertilizer on the growth, yield and protein content of wheat. The treatments tested included an unfertilized control, applying the fertilizer (160 kgN/ha) in one dose at sowing, in two splits at sowing and at tillering, three splits at sowing, tillering and booting, and four splits at sowing, tillering, booting and flowering. The effect of treatments on growth parameters, yield, yield components and protein content was studied. The unfertilized control was significantly the lowest in growth and yield. The tested parameters showed that split application of N fertilizer was superior to application in one dose. Applying N fertilizer in three equal doses at sowing, tillering and booting gave the highest grain yield of wheat. A fourth split given at the time of flowering increased the protein content of grains.
Omkolthoum Abdel Galil Ali
The activities of thermostable proteolytic enzymes produced from the most potent. Streptomyces sp., T. vulgaris, Aspergillus fumigatus and Penicillium sp., isolated from soils of the Eastern Region of Saudi Arabia were investigated. The enzymes were most active toward gelatin at pH 5-7, 6-7, and 5- 5.6, and the optimum temperatures were 50, 50, 40 and 50- 55°C, respectively.
The proteases exhibited extreme thermostability. The enzymes from T. vulgaris and Penicillium sp. retained 100% activity after 30 minutes at 70°C, and those from Streptomyces sp. and A. fumigatus after up to 20 min. After 2 hr at 70°C they lost 22, 45, 33 and 45% of activities, respectively. The protease of Streptomyces sp. was a specific enzyme for gelatin, but the proteases of the other species could hydrolyze casein and albumin also. The enzymes exhibited fair stability at 4°C during 3 months.