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Search Results: 1 - 10 of 341520 matches for " Ameen S. Al-Bareda "
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Numerical Solution of MHD Boundary Layer Flow of Non-Newtonian Casson Fluid on a Moving Wedge with Heat and Mass Transfer and Induced Magnetic Field  [PDF]
Nabil T. El-Dabe, Ahmed Y. Ghaly, Raafat R. Rizkallah, Karem M. Ewis, Ameen S. Al-Bareda
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.36078
Abstract: The paper investigates the numerical solution of the magnetohydrodynamics (MHD) boundary layer flow of non-Newtonian Casson fluid on a moving wedge with heat and mass transfer. The effects of thermal diffusion and diffusion thermo with induced magnetic field are taken in consideration. The governing partial differential equations are transformed into nonlinear ordinary differential equations by applying the similarity transformation and solved numerically by using finite difference method (FDM). The effects of various governing parameters, on the velocity, temperature and concentration are displayed through graphs and discussed numerically. In order to verify the accuracy of the present results, we have compared these results with the analytical solutions by using the differential transform method (DTM). It is observed that this approximate numerical solution is in good agreement with the analytical solution. Furthermore, comparisons of the present results with previously published work show that the present results have high accuracy.
Numerical Solution of MHD Flow of Micropolar Fluid with Heat and Mass Transfer towards a Stagnation Point on a Vertical Plate  [PDF]
N. T. El-Dabe, A. Y. Ghaly, R. R. Rizkallah, K. M. Ewis, A. S. Al-Bareda
American Journal of Computational Mathematics (AJCM) , 2015, DOI: 10.4236/ajcm.2015.52013
Abstract: The paper investigates the numerical solution of problem of magnetohydrodynamic (MHD) micropolar fluid flow with heat and mass transfer towards a stagnation point on a vertical plate. In this study, we consider both strong concentrations (n = 0) and weak concentrations (n = 1/2). The governing equations have been transformed into nonlinear ordinary differential equations by applying the similarity transformation and have been solved numerically by using the finite difference method (FDM) and analytically by using (DTM). The effects of various governing parameters, namely, material parameter, radiation parameter, magnetic parameter, Prandtl number, Schmidt number, chemical reaction parameter and Soret number on the velocity, microrotation, temperature and concentration have been computed and discussed in detail through some figures and tables. In order to verify the accuracy of the present results, we have compared these results with the analytical solutions by using the differential transform method (DTM) and the multi-step differential transform method (MDTM). It is observed that this approximate numerical solution is in good agreement with the analytical solution.
Prepared of Nd: TiO2 Nano Particles Powder as IR Filter via Sol-Gel  [PDF]
Mohammed A. Hamza, Fawaz N. Saiof, Adnan S. Al-ithawi, Majda A. Ameen, Hanna M. Yaseen
Advances in Materials Physics and Chemistry (AMPC) , 2013, DOI: 10.4236/ampc.2013.32024
Abstract:

Doped and undoped nanostructured titanium dioxides were prepared via Sol-Gel method under varying conditions to investigate the effects of neodymium ion doping on the titania optical properties in MID IR range. X-ray diffraction analyses show that the amorphous structure of the prepared samples turns to anatas polycrystalline structure after annealing process at 500°C. FTIR spectrums for pure and doped samples after annealing show a single transmission peak at wave number around 1200 cm-1. The transmission rate of the peak depends on Nd3+ concentrations and its value rises from 1.82% (for pure TiO2) to 86.9% (for doped with 12%wt Nd3+). Shifting on the peak occurs with a maximal shift at 7%wt Nd3+ and then becomes stable at higher concentration. FTIR spectra give a good indication in the direction of preparation of optical band-pass filter at a wavelength around 8.34 μm (~1200 cm-1).

Energy Saving Mechanisms for MAC Protocols in Wireless Sensor Networks
Moshaddique Al Ameen,S. M. Riazul Islam,Kyungsup Kwak
International Journal of Distributed Sensor Networks , 2010, DOI: 10.1155/2010/163413
Abstract: Energy efficiency is a primary requirement in a wireless sensor network (WSN). This is a major design parameter in medium access control (MAC) protocols for WSN due to limited resources in sensor nodes that include low battery power. Hence a proposed MAC protocol must be energy efficient by reducing the potential energy wastes. Developing such a MAC protocol has been a hot research area in WSN. To avoid wasting the limited energy, various energy saving mechanisms are proposed for MAC protocols. These mechanisms have a common design objective—to save energy to maximize the network lifetime. This paper presents a survey on various energy saving mechanisms that are proposed for MAC protocols in WSN. We present a detailed discussion of these mechanisms and discuss their strengths and weaknesses. We also discuss MAC protocols that use these energy saving mechanisms. 1. Introduction A few sensor devices (also called nodes) can be deployed together to create a wireless sensor network (WSN). A WSN can contain few to thousands of these devices at a time. The networks may be dense or sparse with different network topologies. The sensor devices collect data through sensing and monitoring from their respective environment and send to a sink for further processing. As the cost and size of sensor devices decreasing fast, the application areas of such wireless sensor networks have also expanded rapidly. The major application domains [1, 2] are home and office, control and automation, logistics and transportation, environmental monitoring, healthcare, agriculture, security and surveillance, tourism and leisure, military-related activities, education and training, and entertainment. Sensors are now present everywhere including digitally equipped smart homes and buildings, vehicle tracking and detection, monitor of manufacturing process in factories, inventory control, natural habitats, and patients in hospitals, and so on. The requirements in the above applications are as diverse as the application areas themselves. Figure 1 shows typical application areas. Figure 1: Some typical application areas of wireless sensor networks. Sensor devices are tiny in size with constrained processors, limited memory size, low bit rate communications with short transmission range and considerably low in energy capacity compared to other wireless devices such as cell phones and PDAs. A survey of hardware systems for wireless sensor networks can be found in [3]. In most cases, sensor nodes run on batteries that are normally not rechargeable. Energy scavenging [4, 5] for sensor nodes is
Testicular Histopathological Alterations in Rats Treated with Sumithion NP 25/2.5 EC, Insecticide
Mohammed O. Al-Jahdali,Ameen S. Bin Bisher
Journal of Biological Sciences , 2007,
Abstract: The histopathological changes induced by Sumithio NP 25/2.5 EC, a newly formulated organophosphorous insecticide used in dengue fever vector control in Jeddah, Saudi Arabia, on rats testis were investigated. In addition to the control group, four experimental groups of male Wistar rats were daily injected intraperitoneally with two doses of Sumithio NP 25/2.5 EC (1/10 and 1/4 the LD50; 80 and 200 mg kg-1 of body weight, respectively) for two and four weeks. Histological examination revealed significant alterations in the testis of all treated groups including: Focal mild testicular damages, blood hemorrhage and vascular congestion, hypospermatogenesis, dilatation and tubular deformity, cellular vacuolated degeneration (necrosis), aspermatogenesis and tubular destruction and atrophy. The observed pathological changes were dose and time dependent. The testicular toxicity of Sumithio NP 25/2.5 EC was proven and alternative harmless control strategies should be applied.
Some biochemical effects of Aloe vera leaves on tissues in normal mice
M. G. Matti,S. A. Al-Ameen,S. H. Rashed
Iraqi Journal of Veterinary Sciences , 2010,
Abstract: This research was carried out mainly to investigate the effects of the aqueous extract and proteinous fractions of Aloe veraleaves on cholesterol, acetycholinesterase in brain, glycogen, glutathione in liver and malonaldehyde levels in heart in normalmale albino mice. The antioxidant properties and inhibition of acetylcholine-sterase in tissue were detected. Intraperitonealadministration of Aloe vera extract in concentration of 400 mg/kg significantly decreased the levels of AchE in brain by (-88.27%) and glutathione content in liver by (-35.48%), and increased the levels of glycogen in liver and malonaldehyde inheart by (22.60%, 85.50%) respectively. At a concentration of 300 mg/kg Aloe vera extract significantly increased the level ofcholesterol in brain by (24.39%). These results clearly show the antioxidant property of the extract of Aloe vera leaves.
Q-A: Towards the Solution of Usability-Security Tension in User Authentication
Mahdi Nasrullah Al-Ameen,S M Taiabul Haque,Matthew Wright
Computer Science , 2014,
Abstract: Users often choose passwords that are easy to remember but also easy to guess by attackers. Recent studies have revealed the vulnerability of textual passwords to shoulder surfing and keystroke loggers. It remains a critical challenge in password research to develop an authentication scheme that addresses these security issues, in addition to offering good memorability. Motivated by psychology research on humans' cognitive strengths and weaknesses, we explore the potential of cognitive questions as a way to address the major challenges in user authentication. We design, implement, and evaluate Q-A, a novel cognitive-question-based password system that requires a user to enter the letter at a given position in her answer for each of six personal questions (e.g. "What is the name of your favorite childhood teacher?"). In this scheme, the user does not need to memorize new, artificial information as her authentication secret. Our scheme offers 28 bits of theoretical password space, which has been found sufficient to prevent online brute-force attacks. Q-A is also robust against shoulder surfing and keystroke loggers. We conducted a multi-session in-lab user study to evaluate the usability of Q-A; 100% of users were able to remember their Q-A password over the span of one week, although login times were high. We compared our scheme with random six character passwords and found that login success rate in Q-A was significantly higher. Based on our results, we suggest that Q-A would be most appropriate in contexts that demand high security and where logins occur infrequently (e.g., online bank accounts).
Scattering theory with a natural regularization: Rediscovering the J-matrix method
A. D. Alhaidari,H. Bahlouli,M. S. Abdelmonem,F. S. Al-Ameen,T. H. Al-Abdulaal
Physics , 2006, DOI: 10.1016/j.physleta.2006.12.027
Abstract: In three dimensional scattering, the energy continuum wavefunction is obtained by utilizing two independent solutions of the reference wave equation. One of them is typically singular (usually, near the origin of configuration space). Both are asymptotically regular and sinusoidal with a phase difference (shift) that contains information about the scattering potential. Therefore, both solutions are essential for scattering calculations. Various regularization techniques were developed to handle the singular solution leading to different well-established scattering methods. To simplify the calculation the regularized solutions are usually constructed in a space that diagonalizes the reference Hamiltonian. In this work, we start by proposing solutions that are already regular. We write them as infinite series of square integrable basis functions that are compatible with the domain of the reference Hamiltonian. However, we relax the diagonal constraint on the representation by requiring that the basis supports an infinite tridiagonal matrix representation of the wave operator. The hope is that by relaxing this constraint on the solution space a larger freedom is achieved in regularization such that a natural choice emerges as a result. We find that one of the resulting two independent wavefunctions is, in fact, the regular solution of the reference problem. The other is uniquely regularized in the sense that it solves the reference wave equation only outside a dense region covering the singularity in configuration space. However, asymptotically it is identical to the irregular solution. We show that this natural and special regularization is equivalent to that already used in the J-matrix method of scattering.
Extradural Dermoid Cyst of Mastoid Bone: A Case Report
Hamad S. Al-Muhaimeed,Hazem Y. Abdelwahed,Essam A. Elgamal,Ghassan M. Alokby,Ameen M. Binnasser,Masoada M. Ashraf
Case Reports in Otolaryngology , 2012, DOI: 10.1155/2012/548340
Abstract: Dermoid cysts of the head and neck are rare congenital benign tumors. According to the literature they represent about seven percent of all dermoids and less than one percent of all intracranial neoplasms. Extradural dermoid cysts are very rare. We report a case of intracranial extradural dermoid cyst of mastoid bone. We believe that this is the second documented extradural dermoid cyst, the first case reported in the literature (Ammirati et al., 2007) was in close relation to the petrous apex but ours is in close relation to mastoid antrum. Hearing loss was the only clinical presentation in this case, while neurological symptoms were the main presenting symptoms in the first reported case. We present our management of this rare case with respect to the clinical, radiological, histopathological, and surgical aspects and conclude that dermoid tumors, though rare, need to be included in differential diagnosis of middle ear lesions.
Extradural Dermoid Cyst of Mastoid Bone: A Case Report
Hamad S. Al-Muhaimeed,Hazem Y. Abdelwahed,Essam A. Elgamal,Ghassan M. Alokby,Ameen M. Binnasser,Masoada M. Ashraf
Case Reports in Otolaryngology , 2012, DOI: 10.1155/2012/548340
Abstract: Dermoid cysts of the head and neck are rare congenital benign tumors. According to the literature they represent about seven percent of all dermoids and less than one percent of all intracranial neoplasms. Extradural dermoid cysts are very rare. We report a case of intracranial extradural dermoid cyst of mastoid bone. We believe that this is the second documented extradural dermoid cyst, the first case reported in the literature (Ammirati et al., 2007) was in close relation to the petrous apex but ours is in close relation to mastoid antrum. Hearing loss was the only clinical presentation in this case, while neurological symptoms were the main presenting symptoms in the first reported case. We present our management of this rare case with respect to the clinical, radiological, histopathological, and surgical aspects and conclude that dermoid tumors, though rare, need to be included in differential diagnosis of middle ear lesions. 1. Introduction Dermoid tumors are not true neoplasms but are inclusion cysts composed of ectodermal elements. They are uncommon lesions, accounting for approximately 0.3% of all brain tumors and about seven percent of all dermoids of the head and neck [1]. Dermoid cysts are derived from both the ectodermal and mesodermal elements. A keratinizing squamous epithelium is typically present along with dermal derivatives including hair follicles, smooth muscle, and apocrine and sebaceous glands. Fibroadipose tissue is also present. The exact etiology of these neoplasms is unknown though the most likely theories are incomplete closure at lines of fusion or traumatic implantation of skin elements [2]. We report a case of intracranial extradural dermoid cyst of mastoid bone, with respect to the clinical, radiological, histopathological, and surgical aspects. 2. Case Report An 18-years-old girl diagnosed at the age of three years to have right otitis media with effusion (OME) was treated medically. She presented again at the age of 8 years with the same complaint but did not respond to the medical treatment and underwent right myringotomy with ventilation tube and adenoidectomy. Two years later, her symptoms recurred and underwent right T-tube insertion. Symptoms had recurred again after removal of the T-tube 2 years later. She presented at the age of 18 years with right hearing loss and intermittent nonpulsatile tinnitus. There was no history of otorrhoea, otalgia, or vertigo, and there were no abnormal neurological signs or symptoms. Physical examination revealed retracted right tympanic membrane, while the left was normal. Audiogram
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