Khlifi M.A.,Hail University
Journal of Electrical Engineering and Technology | Year: 2016
Solar photovoltaic pumping system is one of most important of renewable energy applications especially in rural areas. Besides, the control strategy for standalone solar pumping system based on induction motor and without DC/DC converter has been widely studied and discussed in the literature. This topology is of great concern due its economic issues, especially when a standard frequency converter (SFCs) with scalar control is used instead of a dedicated PV inverter. This paper proposes an external control module to generate SFCs frequency reference in order to ensure both maximum power point tracking (MPPT). We present method of modeling and control of photovoltaic pumping system based centrifugal pump controlled by new improved incremental conductance in order to optimize the price and operation of pumping system this MPPT algorithm have many advantages like can be eliminate proportional integral controller It is a low cost solution since it requires no additional power equipment. The induction motor driven pump that is powered by a solar array is controlled by the indirect field oriented control (IFOC). The effectiveness of the proposed approach is illustrated by simulations carried out under Matlab Software. The experimental results are compared with simulation results. © The Korean Institute of Electrical Engineers.
Algorinees R.M.,Hail University
Asian Pacific journal of cancer prevention : APJCP | Year: 2016
BACKGROUND: Cigarette smoking is a major public health issue in the Kingdom of Saudi Arabia (KSA) in recent years, particularly among adolescents. Therefore, the aim of this study was to determine the prevalence of cigarette smoking usage among adolescent students in the north of the country.MATERIALS AND METHODS: This cross-sectional study investigated 305 adolescent students from the Northern KSA population, their ages ranging from 11 to 19 years old.RESULTS: Of the 287 respondents, 56/287(19.5%) were found to be current smokers. Of the 56 current smokers, 14/52 (27%), 29/52 (55.8%), and 9/52 (17.2%) smoked 1-3, 4-10 and 11+ cigarettes/day, respectively. For duration most had smoked for 26-36 months.CONCLUSIONS: The findings of the present study indicate that cigarette smoking use is still an important risk behavior among adolescent students. The findings of this study found a significant association of cigarette smoking usage and adolescents various believes and attitude for initiation of smoking and perception toward knowledge of other factors that contribute to the burden of tobacco use.
Mowafy A.E.,Hail University
Moscow University Physics Bulletin | Year: 2016
A theoretical investigation has been made for studying the propagation of ion-acoustic waves (IAWs) in a weakly inhomogeneous, collisionless, unmagnetized, three-component plasmas, whose constituents are inertial ions, nonthermal electrons, and Boltzmannian positrons. Employing reductive perturbation method (RPM), the variable coefficients Korteweg-de Varies equation (KdV) is derived. At the critical ion density, the KdV equation is not suitable for describing the system. Thus, a new set of stretched coordinates is considered to derive the modified variable coefficients KdV equation. Above (below) this critical point the system supports compressive (rarefactive) solitons. The effect of plasma parameters on the soliton profile has been considered. It has been shown that the width and the amplitude of the soliton affected by wave propagation speed, ratio of positron-to-electron density, and nonthermal parameter. © 2016, Allerton Press, Inc.
Alshanti W.G.,Hail University
Applied Computational Intelligence and Soft Computing | Year: 2017
The absence of a general theory that describes the dynamical behavior of the particulate materials makes the numerical simulations the most current powerful tool that can grasp many mechanical problems relevant to the granular materials. In this paper, based on a two-dimensional soft particle discrete element method (DEM), a numerical approach is developed to investigate the consequence of the orthogonal impact into various granular beds of projectile rotating in both clockwise (CW) and counterclockwise (CCW) directions. Our results reveal that, depending on the rotation direction, there is a significant deviation of the x-coordinate of the final stopping point of a spinning projectile from that of its original impact point. For CW rotations, a deviation to the right occurs while a left deviation has been recorded for CCW rotation case. © 2017 Waseem Ghazi Alshanti.
Akhtar S.,Bahauddin Zakariya University |
Sarker M.R.,University of Oregon |
Hossain A.,Hail University
Critical Reviews in Microbiology | Year: 2014
Current food safety issues are deleteriously reshaping the life style of the population in the developing world. Socioeconomic status of the population in poorer economies is one of the major determinants to delineate the availability of safe food to the vulnerable population. Assessment of the prevalence of foodborne illness in developing world is the most neglected area to control disease. Botulism, Shigellosis, Campylobacteriosis, Escherichia coli infection, Staphylococcus aureus infection, Salmonellosis, Listeriosis and Cholerae are extensively prevalent and pose a major threat to human health in underdeveloped communities. The existing food safety status of many African, South Asian, Central, and South American developing countries is distressing therefore; it seems much timely to highlight the areas for the improvement to ensure the supply of safe food to the population in these regions. Extensive literature search at PubMed, Science Direct and Medline was carried out during the current year to catch on relevant data from 1976 to date, using selective terms like food safety, South East Asia, Africa, Central and South America, and foodborne illness etc. Efforts were made to restrict the search to low income countries of these regions with reference to specific foodborne pathogens. This report briefly discusses the present food safety situation in these developing countries and associated consequences as prime issues, suggesting foodborne illness to be the most distressing threat for human health and economic growth. © 2014 Informa Healthcare USA, Inc. All rights reserved.
Okasha N.M.,Hail University
Structural Safety | Year: 2016
The weighted average simulation technique is one of the newest techniques that showed promising capabilities in solving structural reliability problems. In this paper, a modification to the weighted average simulation method is proposed, which allows the computation of the reliability with a small number of performance function evaluations. In addition, an approach for conducting reliability-based design optimization problems by introducing an additional improvement to the weighted average simulation method is proposed. This improvement significantly reduces the number of performance function evaluations needed in the process without sacrificing the accuracy of the results. It was found that the proposed approach can obtain the same results as the original weighted average simulation method with only a fraction of the computational cost required. © 2016 Elsevier Ltd.
Shoaib M.,Hail University
Advances in Astronomy | Year: 2015
The inverse problem of central configuration of the trapezoidal 5-body problems is investigated. In this 5-body setup, one of the masses is chosen to be stationary at the center of mass of the system and four-point masses are placed on the vertices of an isosceles trapezoid with two equal masses m1=m4 at positions ∓0.5, rB and m2=m3 at positions ∓α;/2,rA. The regions of central configurations where it is possible to choose positive masses are derived both analytically and numerically. It is also shown that in the complement of these regions no central configurations are possible. © 2015 Muhammad Shoaib.
Al-Shammery K.A.,Hail University
Journal of Entomology | Year: 2011
Four kinds of plant pollen were tested as an alternative food source for rearing the predatory mite Euseius scutalis (Athias-Henriot) under laboratory conditions of 26°C and 70%RH. Pollen grains were extracted from date palm Pheonyx dactylefira L., sour orange Citrus aurantium L., castor bean Ricinus communis L. and alfalfa Medicago sativa L. Individuals of the predatory mite were collected from leaves of eggplant in Hail district during spring 2010. Mite individuals were provided and reared on the aforementioned pollens for their whole life span. Total developmental period significantly affected by kind of pollen. Date palm pollen highly shortened the development followed by alfalfa, citrus and castor bean. Feeding on date palm pollen caused the highest rate of survival (94%) and gradually declined to 92, 90 and 89% when mites were provided with citrus, alfalfa and castor bean pollen, respectively. During adulthood, female deposited 42.62, 30.22, 21.16 and 13.46 eggs in approximately 12.42, 10.82, 9.44 and 7.22 days when fed date palm, alfalfa, castor bean and citrus pollen, respectively. Mean generation time (T) averaged 17.19, 17.86, 19.08 and 20.47 days; net reproductive rate (R0) 34.93, 30.81, 15.59 and 18.51 fern ale/female/day; intrinsic rate of natural increase (rm) 0.20, 0.192, 0.134 and 0.153; finite rate of increase erm (λ) 1.22, 1.21, 1.14 and 1.15 when mites fed the same kinds of pollen, respectively. The tested plant pollen is considered a suitable alternative food source and meet the nutritional requirements of E. scutalis in Hail, Saudi Arabia. © 2011 Academic Journals Inc.
Ahmed H.G.,Hail University
Asian Pacific Journal of Cancer Prevention | Year: 2013
The aim of this study was to determine the epidemiology of tobacco smoking, toombak dipping and alcohol consumption as risk factors for cancer in the adult population of the northern state of Sudan. Materials and Methods: A cross-sectional survey from March to April 2010, covering 963 adults, was performed. Result: Only 207 had responded, and the male female prevalence was 20.8% and 0.73%. Out of 207 respondents, 29.5% had smoked tobacco in their lifetime, 38% were toombak dippers, while 14% were consumers of alcoholic beverages. Conclusions: The prevalence of toombak dipping was higher than tobacco smoking among the adult population in the northern state of Sudan. Female participation in tobacco and alcohol related studies was found to suffer from major obstacles since these habits are considered as social stigma. Appreciation of the full impact of smoking on population health will definitely make a major contribution to improvement of the poor public health situation in Sudan.
Mahamid I.,Hail University
Engineering, Construction and Architectural Management | Year: 2012
Purpose - The main objective of this paper is to identify the factors that have the potential to cause a contractor's business failure in the West Bank in Palestine and to determine their impact level from the contractor's viewpoint. Design/methodology/approach - A survey of 84 contractors from the West Bank in Palestine was performed. A total of 44 factors were considered in this study and were listed under three groups, i.e. financial, managerial, and external. Findings - Contractors have ranked the following factors as highly influential with huge potential to cause contractor's business failure: fluctuation in construction material costs; delay in collecting dibs from clients; lack of experience in contracts; low margin of profit due to competition; and closure and limitation of movement between West Bank areas. Originality/value - This paper identified the factors that have the potential to cause contractor's business failure in the West Bank in Palestine and determined their impact level from the contractor's viewpoint. Copyright © 2012 Emerald Group Publishing Limited. All rights reserved.