Baghdad, Iraq
Baghdad, Iraq

Nahrain University , also known as Al-Nahrain University and formerly known as Saddam University, is a coeducational public university established in 1988 and located in Baghdad, Iraq. The university offers undergraduate and postgraduate education as well as research opportunities. Until 2003, the university was known as Saddam University, which was then changed to its current name "Al-Nahrain" meaning The Two Rivers . Wikipedia.

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Two texturing methods using porous silicon (PS) and pyramids were performed to investigate the effect of them on the performance of crystalline silicon (c-Si) solar cell. Surface morphology and structural properties of samples have been studied using scanning electron microscopy (SEM) and atomic forces microscopy (AFM). Optical reflectance was obtained using optical reflectometer. I-V characterization of fabricated solar cells was investigated. The results showed the highest conversion efficiency of 13.23% for PS layer compared with 11.36% and 3.70% efficiencies for the solar cells devices with pyramids texturing and as-grown Si, respectively. PS texturing exhibited an excellent reduction in the reflection of incident light compared with pyramids texturing process, with a good light-trapping of wide wavelength spectrum, which could produce high efficiency solar cells. © 2016

Khalifa A.J.N.,Nahrain University | Abdul Jabbar R.A.,Nahrain University
Energy Conversion and Management | Year: 2010

This paper presents an experimental comparative performance study between a storage solar domestic hot water system and a conventional one. The storage system differs from the conventional one by integrating the collector and storage tank into one piece of equipment. The investigated storage collector consists of six 80-mm-outside diameter copper tubes connected in series to act as an absorber and a storage tank. Tests under different flow patterns are conducted to simulate different patterns of hot water consumption. The overall heat loss coefficient, useful heat gain, instantaneous efficiency, efficiency factor, heat removal factor and the temperature distribution along the pipe are determined using modified equations derived for the storage collector from the basic derivation of Hottel-Bliss-Whillier. A comparison between the experimental and theoretical results for the storage collector showed good agreements and that between the two systems showed the superiority of the storage system. © 2009 Elsevier Ltd. All rights reserved.

Khalifa A.J.N.,Nahrain University
Energy for Sustainable Development | Year: 2011

Hybrid systems utilizing renewable energy and conventional diesel generators are important sources for the supply of electricity to remote areas. To maximize the use of the renewable energy resource, the size and operation of the hybrid system components need to be matched to the load and the available renewable resources. The software (HybridRO), which is suitable for the examination of several types of power supply systems using renewable (solar and wind) and conventional energy sources for a Reverse Osmosis (RO) desalination unit, was used to simulate the performance of a hybrid power supply system to provide the required power to an RO desalination plant. A small community in the south of Iraq is chosen in this study as an example of the small communities that depends on ground water for providing drinking and other essential water needs. The study concluded that the lowest water cost is 1.8$/m3 for RO unit powered by either a diesel generator or by a combination of diesel, wind, and solar power. Relying on renewable energy only increase the water cost to 2.3-2.4$/m3 depending on the source type. A significant reduction in the fuel burned occurred with the introduction of the renewable energy sources. © 2011 International Energy Initiative.

Khalifa A.J.N.,Nahrain University
Energy Conversion and Management | Year: 2011

Many experimental and numerical studies have been carried out on different configurations of solar stills to optimize the design by investigating the effect of climatic, operational and design parameters on its performance. One of the main parameters that have received a considerable attention is the cover tilt angle. A large number of studies on the effect of cover tilt angle on productivity in different seasons and latitude angles are cited in this article. The investigation that tackle the detailed effect of the cover tilt angle on productivity report contradictory conclusions about the effect of tilt angle on productivity and the value of the optimum tilt angle. A relation between the cover tilt angle and productivity of simple solar still in various seasons is established together with a relation between the optimum tilt angle and the latitude angle by an extensive review of the literature. The conclusions of this study should assist in choosing the proper cover tilt angle in various seasons and latitudes. © 2010 Elsevier Ltd. All rights reserved.

Dawood M.S.,Nahrain University | Salman S.D.,University of Baghdad
Lasers in Medical Science | Year: 2013

The effect of wound illumination time by pulsed diode laser on the wound healing process was studied in this paper. For this purpose, the original electronic drive circuit of a 650-nm wavelength CW diode laser was reconstructed to give pulsed output laser of 50 % duty cycle and 1 MHz pulse repetition frequency. Twenty male mice, 3 months old were used to follow up the laser photobiostimulation effect on the wound healing progress. They were subdivided into two groups and then the wounds were made on the bilateral back sides of each mouse. Two sessions of pulsed laser therapy were carried along 15 days. Each mice group wounds were illuminated by this pulsed laser for 12 or 18 min per session during these 12 days. The results of this study were compared with the results of our previous wound healing therapy study by using the same type of laser. The mice wounds in that study received only 5 min of illumination time therapy in the first and second days of healing process. In this study, we found that the wounds, which were illuminated for 12 min/session healed in about 3 days earlier than those which were illuminated for 18 min/session. Both of them were healed earlier in about 10-11 days than the control group did. © 2012 Springer-Verlag London Ltd.

Naif H.M.,Nahrain University
Infectious Disease Reports | Year: 2013

Over the past three decades of intense research on the contribution of viral and host factors determining the variability in HIV-1 infection outcome, HIV pathogenesis is still a fascinating topic that requires further study. An understanding of the exact mechanism of how these factors influencing HIV pathogenesis is critical to the development of effective strategies to prevent infection. Significant progress has been made in identifying the role of CCR5 (R5) and CXCR4 (X4) HIV strains in disease progression, particularly with the persistence of R5 HIV-1 strains at the AIDS stage. This indicates that R5 strains are as fit as X4 in causing CD4+ T cell depletion and in contribution to disease outcome, and so questions the prerequisite of the shift from R5 to X4 for disease progression. In contrast, the ability of certain HIV strains to readily use CXCR4 for infection or entry into macrophages, as the case with viruses are homozygous for tropism by CCR5delta32. This raises another major paradox in HIV pathogenesis about the source of X4 variants and how do they emerge from a relatively homogeneous R5 viral population after transmission. The interactions between viral phenotypes, tropism and co-receptor usage and how they influence HIV pathogenesis are the main themes addressed in this review. A better understanding of the viral and host genetic factors involved in the fitness of X4 and R5 strains of HIV-1 may facilitate development of specific inhibitors against these viral populations to at least reduce the risk of disease progression. © H.M. Naif, 2013.

Saheb D.A.,Nahrain University
Journal of Engineering and Applied Sciences | Year: 2011

Metal Matrix Composites (MMCs) have been used in several applications in aerospace and automotive industries. Although several technical challenges exist with casting technology. Achieving a uniform distribution of reinforcement within the matrix is one such challenge, which affects directly on the properties and quality of composite. In the present study a modest attempt has been made to develop aluminium based silicon carbide particulate MMCs, graphite particulate MMCs with an objective to develop a conventional low cost method of producing MMCs and to obtain homogenous dispersion of ceramic material. Experiments have been conducted by varying weight fraction of SiC, graphite and alumina (5%, 10%, 15%, 20%, 25%, and 30%), while graphite weight fraction 2%, 4%, 6%, 8% and 10% keep all other parameters constant. The results indicated that the 'developed method' is quite successful to obtain uniform dispersion of reinforcement in the matrix. An increasing of hardness and with increase in weight percentage of ceramic materials has been observed. The best results (maximum hardness) have been obtained at 25 % weight fraction of SiC and at 4% weight fraction of graphite. © 2006-2011 Asian Research Publishing Network (ARPN).

Ibrahem M.K.,Nahrain University
2012 International Conference on Future Communication Networks, ICFCN 2012 | Year: 2012

There are networks and entity groupings that require entity authentication while preserving the privacy of the entity being authenticated. Zero-knowledge proof (ZKP) plays an important role in authentication without revealing secret information. Diffie-Hellman (D-H) key exchange algorithm was developed to exchange secret keys through unprotected channels. In this paper D-H algorithm has been modified into an interactive zero-knowledge proof protocol. The proposed protocol is designed to satisfy the zero-knowledge proof properties and resists the known attacks. © 2012 IEEE.

In the present work, the non-constrained optimization for three proposed models of PNP molecule onto TiO 2 (100) surface has resulted in three molecular adsorption conformations; a vertical alignment via bridged NO 2, a parallel alignment bridges via NO 2 and OH groups, and a monodentate vertical alignment bridged via OH. The first configuration is the dominant adsorption structure. The adsorption energy for the bridging geometries is found to be much more stable than that of the monodentate conformer. The predicted VDOS spectra indicate that the main interaction between PNP molecule and the surface of TiO 2 takes place through a linkage between the Lewis acid sites, fivefold Ti (V) and fourfold Ti (IV) coordinated titanium surface atoms, and the nitro or phenolic oxygen atoms. Frontier electron theory (FET) and Wheland localization approach (WLA) have been applied for the prediction of the primary •OH initiated oxidation intermediates. These approaches highlight similar expectations for the variation in the reactivity of the ring positions, towards the hydroxyl radical attack. By comparison with the available experimental data and other theoretical calculations, it is shown that MSINDO can reproduce literature data with acceptable accuracy. © 2011 Elsevier B.V. All rights reserved.

Al Ahmed A.A.N.,Nahrain University
Arabian Journal of Geosciences | Year: 2013

Chemical analysis was carried out to evaluate the potentiality of rock samples having hydrocarbon characteristics, identified by chemical methods as one of the approaches to evaluate the source rocks encountered from Sehkanian, Sargelu, Naokelekan, Sarmord and Ghia Gara of (Middle to Upper Jurassic-Lower Cretaceous) stratigraphic sequence of Iraq, representing source rocks, which are recovered from oil exploratory wells Butmah-15, Ajeel-8, Makhul-2, Qarachuq (1 and 2) and TaqTaq-1 (Bm-15, Aj-8, Mk-2, Qc-1,Qc-2 and Taq-1) alternatively, located in the northern part of Iraq and also the outcrop samples extracted from the type locality at Surdash Anticline. Additional samples were taken from another exposure section of the Jurassic rocks from Banik village, those various samples represent Varity of palynofacies. The bulk of chemical analysis enables to enhance the potentiality of the source rocks, leading to believe generating tremendous amount of oil and subordinate gas promising more than earlier predictions for forming super giant oil and thermogenic gas fields in this area. The value of the production indices determines that the system of the oil in Iraq is not widely different from the depocenters of the surrounding countries. Accordingly Iraq is considered as an ideal and systematic basin that all the total petroleum system elements are available, giving indications of good source rocks, extensive reservoirs and excellent seals. Typical oil fields, which as determined by the remarkable total organic carbon exceeds 20 %, and maturation evidences accompanied with maximum temperature up to 450°C indicate obviously various values of the hydrogen and oxygen indices, kerogen type II and type III, of marine to mixed to terrestrial origin that lead to determine that the oil and gas prone Sargelu, Naokelekan and Ghia Gara were good source rocks. Meanwhile Barsarin and Sarmord were reservoir rocks. The area of study is widely promising to produce oil with condensed gas. © 2012 Saudi Society for Geosciences.

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