ABSTRACT

Background: This study investigated the γ-rays shielding properties of some building materials in Sudan has been investigated. Materials and Methods: Photons attenuation coefficients and half value layer (HVL) were experimented using Cs-137 and Co-60 sources. The measurements were performed to gauge the intensity of radiation when performed unshielded, the specific thickness of selected samples was examined, using an ion chamber placed at 2 meters from Cs-137 and Co-60. Results: The results indicated that the linear attenuation coefficient (µ) possesses a linear relationship with the corresponding densities of the samples studied and inversely with photon energy. HVL was directly proportional with photon energy. Conclusion: As a result of this evaluation the study concluded that selected samples were suitable as shielding material for gamma radiation in Sudanese laboratories.

Field experiments were carried out at Sidi Salem District, Kafr El-Sheikh governorate to study the influence of two nitrogen rates in combination with phosphorus (P) and Potassium (K) at their balance rate N:P:K = by ratio of (67:30:24) and high (N) rate 1.5N:P:K by ratio of (100.5:30:24) on the population numbers of cotton aphids and whitefly (adults) infesting cotton crop in addition to some associated predators during tow seasons (2011 and 2012). Obtained results revealed that the population densities of aphids and whitefly (adult) were maximum during mid and later stages of cotton seasons according to temperature (Temp.) and relative humidity (R.H %) levels. The highest means of aphid, whitefly and associated predators populations in both study seasons were scouted in plot fertilized with high N fertilization 1.5N:P:K and vice versa. Statistical analysis showed highly significant differences between the population means of aphids, whitefly (adults) and associated predators No. in the two fertilizer ratios in both seasons. Also, the population densities of aphids and whitefly was higher in 2012 than that in 2011 season, it is dependent upon of the corresponding Temp. and R.H %. On the other hand, insignificant positive correlation was found between predators and aphids and whitefly (0.290 and 0.042) respect. in plants fertilized with N:P:K ratio, while there was highly positive correlation (0.697 and 0.608) with both sucking insects respect. in 1.5N:P:K during 2011 season. But, in 2012, season predators was positive and highly significant correlated (0.789 and 0.881) with aphids and whitefly respect. in fertilization ratio 1.5N:P:K. Highly significantly positive (0.728) and significant positive (0.500) correlations were found with aphids and whitefly respect. with fertilization N:P:K ratio.

and Technology during the period 15/07-02/09/2018 to determine the effect of replacing fishmeal with baobab seed meal in the formulation of diets for Nile Tilapia (O. niloticus) fish and determining effect on the growth rate. The experiment included 12 plastic aquariums, Fish were distributed randomly in aquariums and placed in each one 10 fish. Acclimatized to the hatchery conditions for 3 days, before the beginning of the experiment. The experiment included 4 treatments with 3 replicated aquariums for each. Feeds T0, T1, T2 and T3 (The diets replacing 0, 25, 50 and 75% of fish meal protein content by baobab seed meal. The results indicated that final body weight (BW), weight gain (WG) and specific growth rate (SGR) of O. niloticus increased with increasing level of fish baobab seed meal in diets. WG was found 20.10, 28.23 and 37.90 for T1, T2 and T3 respectively. The data were analysed by one-way analysis of variance (ANOVA, F test) and LSD for significantly different means at a significance level of 0.05 using SPSS version 16.

Raising software abstraction and re-use levels are key success factors for producing quality software products. Model-driven architecture (MDA) is an OMG initiative following this trend by mapping a conceptual model of application specified in platform independent model (PIM), to one or more platform specific models (PSM) automatically. Because there is little previous work tackling the development problem from specification through to implementation, this paper proposes End to End Development engineering (E2EDE) method using MDA methodology. E2EDE is intended to fill the mapping gap between PIM and PSM in MDA. The notion of variability is utilized from software product line and used to model design decisions in PSM. PIM is equipped with Nonfunctional requirements which borrowed from Design pattern to inform design decisions; thereby guiding the mapping process. In addition we have developed a strategic PSM for messaging systems can be configured to produce different applications such as the helpdesk system which is used as a case study