http://onlinejournals.uofk.edu/index.php/sesj/issue/feed 2021-08-30T11:53:03+00:00 Open Journal Systems http://onlinejournals.uofk.edu/index.php/sesj/article/view/153 2021-08-30T11:08:53+00:00 Ahmed M. Elsharief ojs@uofk.edu Abdel Karim M. Zein ojs@uofk.edu Hussein Elarabi ojs@uofk.edu Rasha Abulgasim ojs@uofk.edu

<p>The term Nubian Sandstone Formation or Nubian Formation (NF) is applied in the Sudan to those bedded and usually flat-lying conglomerates, grits, sandstones, sandy mudstones and mudstones that rest unconformably on the Basement Complex and the Paleozoic sandstones. These formations are either exposed or covered by the recent quaternary formations. They cover large areas in Northern, Central Western and Eastern Sudan. Several important heavy structures such as bridges across the rivers and high rise buildings in Khartoum are supported on these formations. The factors controlling their performance as foundation materials are the type and amount of cementing material for the sandstones; the heterogeneity, degree of weathering and the type and consistency of the mudstones and the characteristics of the formations covering them. Different approaches were used for the design of piles resting or penetrating NF. This paper summarizes the geotechnical characteristics of five bridge sites in Khartoum and the approaches used by the designers for estimating the bearing capacity of the piles supporting these bridges. The piles were all socketed into the NF. The designs were compared with the results from pile load tests carried out in the bridge sites. The analysis has shown that the approaches used for estimating the pile capacities in the NF are very conservative and un-realistic. Alternative design approaches or improvements of the currently used designs are needed</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals http://onlinejournals.uofk.edu/index.php/sesj/article/view/154 2021-08-30T11:15:54+00:00 Auday A.H. Mohamad ojs@uofk.edu Essar Gafar Ahmed ojs@uofk.edu

<p>Modeling of protective relays is economical and feasible alternative to investigate the performance of relays and protection systems. This paper presents a new approach for MHO Relay Algorithm in MATLAB based on Fast Fourier Transform Algorithm (FFT) which can estimate exact magnitude of DC offset component and completely eliminates it from operating quantities during faults and also makes use of smoothing window to filter out noise if any. The proposed Numerical Algorithm performance is tested on simulated transmission line of Merowe-Atbara 500 KV, 50 Hz, and 236.7 Km using data generated by PSCAD/EMTDC. The proposed MHO algorithm evaluated by using MATLAB to models a power system and simulates many fault conditions on a selected transmission line such as different Fault locations, resistances with various fault angles. Sample results of these studies show the comparison between the presented Algorithm and PSCAD/EMTDC in detection and tripping time</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals http://onlinejournals.uofk.edu/index.php/sesj/article/view/155 2021-08-30T11:20:20+00:00 Mohamed Mustafa Elnour Ahmed ojs@uofk.edu

<p>It is unknown to many of the science of corrosion as old as history, where scientists have the Romans and Greeks like Pliny, Austin, and others, are built the first building blocks of the science of corrosion, through which has knowledge of the most important developments in the science of metals, Through this study determine with any kind of corrosion can be chosen in Oil and Gas industry so that the appropriate corrosion prevention and control measures, or so as to avoid corrosion problems in the future. This study also analyzes the causes that lead to the high volume of corrosivity such as environmental conditions and accompanying crude acids, gases, and production conditions in different stages.</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals http://onlinejournals.uofk.edu/index.php/sesj/article/view/156 2021-08-30T11:29:42+00:00 Enas Abu Obieda Abd El Gadir Hilal ojs@uofk.edu Taj Alasfia Mubarak Barakat ojs@uofk.edu

<p>The present study addresses all facets of equipment sizing and an efficient, safe and environmentally acceptable crude oil dehydration operation based on three different equipments. The liquid-liquid separator, heater-treater system and electrostatic coalescer equipments will be considered in this work. Case studies present the effect of crude oil properties and operating conditions on the right decision on equipment selected. The selection is based on mathematical equations that characterize the choices of the separation system through the determination of the required size and efficiency. The results of this study show that the liquid-liquid separator is suitable for dehydration of light crude oil density (less than 850 kg/m3) and low water-cut (water content) (less than 40%) crudes since it gives reasonable efficiency. The heater-treater system is found to be giving high efficiency. Furthermore the study concludes that the electrostatic coalescer is most suitably used for dehydration of crude oil with water cut 20% or less because short circuiting occurs above this limit; In this case the electrostatic coalescer gives the highest efficiency with the lowest size requirements.</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals http://onlinejournals.uofk.edu/index.php/sesj/article/view/157 2021-08-30T11:39:03+00:00 Sameir M. Ali Hamed ojs@uofk.edu S. O. Bashir ojs@uofk.edu Ashraf A. Osman ojs@uofk.edu

<p>This paper presents exact electromagnetic fields expressions of a circular loop antenna (CLA) with an arbitrary current and dimensions placed over a perfect electric conducting ground plane. Fields derivations are based on the spherical Bessel functions (SBFs) and associated Legendre polynomials (ALPs) expansion. These expressions are valid everywhere above the ground plane except on the loop. The field expressions presented in this paper reduces to the known far-field expressions of the loop antenna over ground plane when large argument approximations for SBFs are applied. Moreover, approximate expressions in the near-fields region are derived from the exact fields. Fields of the uniform CLA over ground plane and that on the axis of the loop are obtained as special cases. The results from the simulation software AN-SOF are in excellent agreement with the results obtained using the field expressions presented in this paper which reveals the correctness of these expressions.</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals http://onlinejournals.uofk.edu/index.php/sesj/article/view/158 2021-08-30T11:42:37+00:00 Ghassan Mohammed Taha Abdalla ojs@uofk.edu

<p>Wireless connectivity is essential for vehicle ad hoc (VANET) communications and it is vital for safety applications. Previous work considered the connectivity of a linear finite network where cars are uniformly distributed in an infinite single dimension which is not realistic. In this paper the connectivity of vehicle network is calculated for single and multi-lane roads. The spaces between cars on the road are considered to follow the exponential distribution in a two dimensional topology. The probability of full connectivity and average network connectivity of VANET with single and multi-lane roads is analysed. For communication range R, car densities of 7cars/R or more were found sufficient to provide high connectivity within the city compared to 12cars/R for highways. Roads with several lanes show higher average connectivity but lower probability of full connectivity. We also investigated the effect of penetration rate on connectivity and found that while penetration rates of 50-100%, 10cars/R provide 80% probability of full connectivity, this reduces to 10% for 5-20% penetration</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals http://onlinejournals.uofk.edu/index.php/sesj/article/view/159 2021-08-30T11:51:33+00:00 الهام بدور ojs@uofk.edu حسن الحاجي ojs@uofk.edu ميساء السوادي ojs@uofk.edu

<p>The transport with different forms, is the primary key of the economy, in all countries as it is an essential element in the social life of each human societies, but at the same time it is one of the main sources of air pollution, especially if this sector is not subject to strict laws, such as determining the age of a specific transport permitted to use within the big cities, in addition to strict periodic tests on these means, and application instructions meticulously. This search focuses on the analysis of the problem of air pollution, and to identify the most important air pollutants, and then deals with the study of the influence of the traditional means of transport in the major cities on the rates of air pollution, and apply it to the city of Aleppo. And the procedures that we have make to reduce the air pollution in the big cities, including Aleppo</p>

2021-08-30T00:00:00+00:00 Copyright (c) 2021 Sudan Eng. Society Journals