Nile Valley University or Wadi El-Neel University is a public university located in Khartum Sudan.It was founded in 1990.Nile Valley University is a member of the Federation of the Universities of the Islamic World.As of September 2011, the university was a member in good standing of the Association of African Universities. Wikipedia.
Hamed S.M.A.,Nile Valley University
Proceedings - 2015 International Conference on Computing, Control, Networking, Electronics and Embedded Systems Engineering, ICCNEEE 2015 | Year: 2015
Exact magnetic field expressions are derived for a system of concentric circular-loops antenna above a perfectly electric conducting (PEC) ground plane in this paper. The current distributions and dimensions of the loops are arbitrary. Simplified expressions for the antenna with uniform current loops and the fields on the axis of the antenna are obtained as special cases from the general expressions. Moreover, the static magnetic fields f000or concentric current loops are obtained from the general expressions by letting the propagation constant approaching zero. The numerical results from the field expressions presented in this paper are in excellent agreement to those from AN-SOF simulation software, which check the correctness of these expressions. © 2015 IEEE.
Ali Hamed S.M.,Nile Valley University
Advanced Electromagnetics | Year: 2015
This paper presents a simple formulas for designing broadband concentric circular-loops antennas (CCLAs). The loop dimensions for widest bandwidth are derived and expressed in terms of driven loop resonance frequency. The analysis addresses CCLAs with and without ground planes senarios.The derived formulas are used to design multiple CCLAs. For example, a 3-elements CCLA of a maximum radius of 6.34 cm can be designed to operate with a voltage standing wave ratio (VSWR) < 2 over the frequency band with fractional bandwidth of 16.9% with a minimum directivity of 3.9 dB. Addionationally, a 4-elements CCLA of maximum radius of 15 cm can be design to operate in the frequency band extending from 825 MHz to 991 MHz (fractional bandwidth of 18.3%) with a VSWR < 2 and directivity higher than 5.2 dB over the entire band. Furthermore, the analysis shows that a 3-elements CCLA backed with a conducting ground plane improves the fractional bandwidth to 19.6% and directivity to 9.15 dB over the band of interest. The analytical results on designed antennas are validated with simulation results obtained by using the AN-SOF antenna simulation software. An excellent agreement is observed between analytical and AN-SOF simulations results. © 2015 by Advanced Electromagnetics. All rights reserved.
Ahmed B.M.,Nile Valley University |
Taha K.M.,Atbara Veterinary Research Laboratory |
Enan K.A.,Central Laboratory |
Elfahal A.M.,Central Laboratory |
El Hussein A.R.M.,Animal Resources Research Corporation
Vaccine | Year: 2013
Malignant ovine theileriosis caused by Theileria lestoquardi is an economically important disease infecting small ruminants in the Sudan. The disease causes massive losses among sheep in many regions of Northern Sudan. The present studies were done to isolate lymphoblastiod cells infected with malignant ovine theileriosis and attenuate them by passage using culture media to develop and produce schizonts candidate vaccine, then test its efficacy and safety by exposing immunized lambs to field challenge in an area endemic with T. lestoquardi. In the present experiments we isolated and established an in vitro culture of T. lestoquardi infected lymphoblast cell line. Long-term culture of T. lestoquardi infected lymphoplastoid cells was shown to result in attenuation of their virulence and lambs inoculated with different doses of such cells at passage 105 exhibited very mild reactions with fever that lasted for 1-5 days and parasitaemia of <0.2%. The experimental lambs immunized with this candidate vaccine were immune and protected when exposed to field challenge in an area endemic of ovine theileriosis, while morbidity and mortality among non-immunized animals reached 76.9% and 46.15%, respectively, and they exhibited the clinical signs of malignant ovine theileriosis that included, high fever, loss of appetite, enlargement of lymph nodes, jaundice, loss of weight and death. The present study demonstrates the efficacy and the safety of this attenuated cell line as a live attenuated candidate vaccine. © 2013 Elsevier Ltd.
Hamed S.M.A.,Nile Valley University
IEEE Transactions on Antennas and Propagation | Year: 2014
The author would like to thank the commentators, Dr. Zheng and Dr. Li, for reviewing and commenting on the work reported in . The author disagrees with their conclusion that the author in  is 'criticizing the merits' of their published papers. The author is merely explaining the differences between the author's work in  and the commentators' work reported in . This should not detract from the contribution they made in  as indicated in their comments. © 1963-2012 IEEE.
Ali Hamed S.M.,Nile Valley University |
Abbas M.A.H.,University of Khartoum
IEEE Transactions on Antennas and Propagation | Year: 2012
A hybrid procedure to study the characteristics of the circular loop antenna (CLA) placed coaxially relative to a conducting body of revolution (CBOR) is presented. The procedure uses the well known theory for the thin wire CLA analysis that is based on Fourier series expansion, with the analysis based on numerical computation of Green's functions for bodies of revolution. The procedure is general and can be applied to study the characteristics of CLA placed coaxially relative to any CBOR. The input admittance computed using this procedure for loop/sphere case is in good agreement with published results. © 1963-2012 IEEE.