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Search Results: 1 - 10 of 19015 matches for " Rami Al-Ghamdi "
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Evolutionary Computation Techniques for Predicting Atmospheric Corrosion
Amine Marref,Saleh Basalamah,Rami Al-Ghamdi
International Journal of Corrosion , 2013, DOI: 10.1155/2013/805167
Abstract:
Evolutionary Computation Techniques for Predicting Atmospheric Corrosion
Amine Marref,Saleh Basalamah,Rami Al-Ghamdi
International Journal of Corrosion , 2013, DOI: 10.1155/2013/805167
Abstract: Corrosion occurs in many engineering structures such as bridges, pipelines, and refineries and leads to the destruction of materials in a gradual manner and thus shortening their lifespan. It is therefore crucial to assess the structural integrity of engineering structures which are approaching or exceeding their designed lifespan in order to ensure their correct functioning, for example, carrying ability and safety. An understanding of corrosion and an ability to predict corrosion rate of a material in a particular environment plays a vital role in evaluating the residual life of the material. In this paper we investigate the use of genetic programming and genetic algorithms in the derivation of corrosion-rate expressions for steel and zinc. Genetic programming is used to automatically evolve corrosion-rate expressions while a genetic algorithm is used to evolve the parameters of an already engineered corrosion-rate expression. We show that both evolutionary techniques yield corrosion-rate expressions that have good accuracy. 1. Introduction Corrosion is a natural phenomenon that can cause substantial economic and environmental losses which result from the damage incurred in metal constructions over the years. The cost of corrosion has been reported [1, 2] to be as large as 3.1% of the gross domestic product of countries such as the United States, United kingdom, and Australia. Corrosion costs can be (i) direct when the metallic structure is greatly damaged in which case replacement or expensive maintenance are required or (ii) indirect when the worsened appearance of the construction reduces its value (even if the construction is not greatly damaged and can still be used just fine). Corrosion refers to the disintegration of materials into their constituent atoms because of chemical or electrochemical reactions with the environment [3]. This disintegration causes a loss in the thickness of the construction which results in a decrease in resistance and strength and consequently a decrease in the service performance of the construction. Corrosion occurs in many engineering structures such as bridges, pipelines, refineries, and so forth and can result in the destruction of materials in a gradual manner and hence shortening their lifespan. Corrosion can occur in many environments such as atmosphere, soil, sea, and so forth where environmental factors affect the material in complicated processes leading to its corrosion. Depending on the environment, corrosion can be atmospheric, underground, marine, gaseous, or microbial and bacterial. Atmospheric
Stripping Voltammetric Determination of Timolol Drug in Pharmaceuticals and Biological Fluids  [PDF]
Ali F. Al-Ghamdi
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.22020
Abstract: A sensitive and reliable stripping voltammetric method was developed to determine timolol drug. This method is based on the adsorptive accumulation of the drug at a hanging mercury drop electrode (HMDE) and then a negative sweep was initiated, which yield a well defined cathodic peak at –850 mV versus (Ag/AgCl) silver reference electrode. To achieve high sensitivity, various experimental and instrumental variables were investigated such as supporting electrolyte, pH, accumulation time and potential, scan rate, frequency, pulse amplitude, convection rate and working electrode area. The monitored adsorptive current was directly proportional to the concentration of timolol and it shows a linear response in the range from 1 × 10–7 to 1.5 × 10–6 mol●l–1 of this drug (correlation coefficient = 0.998) and the detection limit (S/N = 3) is 1.26 × 10–9 mol●l–1 at an accumulation time of 30 sec. The developed adsorptive stripping voltammetry (AdSV) procedure shows a good reproducibility, the relative standard deviation RSD% (n = 8) at a concentration level of 1 × 10–6 mol●l–1 of timolol was 0.13%, whereas the method accuracy was indicated via the mean recovery of 110% ± 1.414%. Possible interferences by several substances usually present in the pharmaceutical formulations have been also evaluated. The applicability of this approach was illustrated by the determination of the drug in pharmaceutical preparation and biological fluids such as serum and urine.
Occupational Exposure to Paints Causes Impairment of Kidney Functions  [PDF]
Saeed S. Al-Ghamdi
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.25061
Abstract: It has been suggested that exposure to organic solvents may have a role in the impairment of kidney function that may progress to kidney failure. However, this has never been evaluated with an appropriate analytical study of the kidney functions of those people who are chronically exposed to these chemicals. This study was designed to measure the kidney function of car painters in the city of Makkah, Saudi Arabia. Fifty workers were selected at random for this study and compared to thirty male medical students who were taken as a control group. Blood samples were collected for the analysis of kidney function. The levels of blood urea nitrogen (BUN), creatinine, and uric acid were scientifically higher in the tested group compared to the control group. In addition to this, the levels of these parameters were significantly higher in the serum of car painters who worked in this industry for more than ten years compared to painters who worked for less than ten years. Moreover, the number of car painters who were not using protective gloves and masks during working hours were 43 and the number of car painters who visited specialized clinics because of kidney problems were 45 of the 50 tested volunteers. These findings support the hypothesized association of solvent exposure with the development of chronic renal failure. They should prompt clinicians to give greater attention to patients’ occupational exposures. Routine monitoring of kidney functions and the use of protective materials are of greater importance to minimize the occupational diseases caused by organic solvents.
Seed Morphology of Some Species of Indigofera (Fabaceae) from Saudi Arabia (Identification of Species and Systematic Significance)  [PDF]
F. A. Al-Ghamdi
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.23057
Abstract: Seeds of 18 species of Indigofera L. were examined with the scanning electron microscope and the light microscope. Macro- and micromorphological characters, including seed shape, colour, size, surface, epidermal cell shape, anticlinal boundaries, outer periclinal cell wall and relief of outer cell walls, are presented. Two types of basic anticlinal cell wall boundaries and two types of relief outer cell walls are recognized and two different shapes of the outer periclinal cell wall are described. A key for the identification of the investigated taxa based on seed characters is provided.
Performance Analysis of Automated Control System for Condenser Water Treatment Unit  [PDF]
Abdulmajeed Saeed Al-Ghamdi
Engineering (ENG) , 2012, DOI: 10.4236/eng.2012.41008
Abstract: The air conditioning system in the Umm Al-Qura University (Albdiya Campus) was conceived to be a district cooling by a remote chilled water plant. Recently, there are two chilled water plants in the university installed strategically to provide chilled water to all the academic and administrative buildings of the university through distribution network with total capacity approximately of 12,000 tons of refrigeration. The plants were built based on cooling towers with open water cycle as heat rejection system. Water treatment chemicals has been used to protect the cooling systems from corrosion, scaling and microbiological fouling accompanied with dissolved and suspended water impurities. Different methods are being used to determine and control the treatment chemical concentrations and system performance indicators. Traditional chemical controller has drawback of indirect measurements and set points. The purpose of this paper is to present a solution to overcome the problems of traditional and conventional chemical treatment and control sys-tems. Central cooling plant number (1) assigned to perform experimental setup using new chemical treatment technology. Advanced automatic chemical treatment controller installed on condensers (1, 2 and 3), and certain key performance indicators were selected and monitored such as chemical and water consumption, power, energy saving, and maintaining system integrity and efficiency. Satisfactory results were obtained in terms of performance and cost of operation.
Inhibition of calcium oxalate nephrotoxicity with Zamzam water  [PDF]
Saeed S. Al-Ghamdi
Open Journal of Preventive Medicine (OJPM) , 2012, DOI: 10.4236/ojpm.2012.21010
Abstract: Zamzam water is well known of its high conductivity. For this fact urologist and nephrologists recommend their patients who are suffering from kidney stones not to drink this water because it could worse their health status. This study was conducted to investigate the effect of Zamzam water on calcium oxalate nephrotoxicity in experimentally induced kidney stones in male Wistar albino rats. Calcium oxalate crystals were induced by orally administration of 200 mg of glycolic acid dissolved in the drinking water. The rats were divided into three groups; six rats each. These include positive control group (given glycolic acid), test group (given glycolic acid plus Zamzam water) and negative group (given drinking water only). After two weeks of treatment, blood analysis of blood urea nitrogen (BUN) and creatinine showed significant differences in positive control group compared to the negative control group, whereas no significant differences were noticed in the level of BUN and creatinine between both the negative control and the test group. Moreover, urine analysis showed a high density of calcium oxalate crystals in the positive control group, whereas no crystals were detected in the negative control and the test groups. Histopathological investigations showed damaging in kidneys of the positive control group with no tissue abnormalities in the negative control and the test group. I concluded from this study that Zamzam water prevents the formation calcium oxalate stone, which probably mean that it has no negative effect on patients suffering from kidney disorders due to crystals formation.
The Reproductive and Thyroid Hormonal Profile of Khat (Catha Edulis) Chewers  [PDF]
Saeed S. Al-Ghamdi
Pharmacology & Pharmacy (PP) , 2012, DOI: 10.4236/pp.2012.34060
Abstract: The effects of khat on the hormonal levels have been established; however, the effects on human beings are controversial. The aim of our study was to investigate the possible effects of khat on the levels of serum thyroid hormones, testosterone, estradiol (E2), prolactin and cortisol in men. A total of 50 blood samples were collected from healthy males who referred to chew khat for more than 10 years and analyzed for the above hormones. The results were compared to the hormonal levels of 35 non khat chewers. Chewing khat causes significant increases in the testosterone (P < 0.03), prolactin (P < 0.05), E2 (P < 0.00005), FT3 (P < 0.04), and TSH (P < 0.05) levels. No significant differences were found in the serum level of FT4 between the two groups. The level of cortisol were significantly lower (P < 0.001) in the khat chewers group compared to the control group. This study suggests that khat chewing can cause reduction in the cortisol level, which may cause increases of testosterone, prolactin and E2. In addition, chewing khat increases the level of TSH and FT3 serum levels. Therefore, khat may contribute to the relevant disorders caused by abnormal levels of the studied hormones in the people who are chewing khat
Morphological Diversity of Some Tephrosia Species (Fabaceae) in Saudi Arabia  [PDF]
Faraj A. Al-Ghamdi
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.43070
Abstract:

Morphological features of nine wild species belonging to the genus Tephrosia PER growing in Saudi Arabia were extensively studied in order to support the diversity and simplify the identification of these species. The studied features included macro and micro morphological features of stem, leaves, flowers and pods. The most important features regarded for distinction of Saudi Arabia species of Tephrosia were pods shape, color, size, dehiscence and number of seeds per pod, inflorescences position, flower opening, shape of the upper 2 teeth of calyx, shape of sepals apex, shape of wings, length of hairs on ovary, direction of staminal tube tip, leaflets shape and surface and stem habit form and life spin. A key for the identification of the investigated species based on these morphological features is provided.

Soil Microbial Biomass of Pea (Pisium sativum cv. Little Marvel) in Response to Three Atmospheric Air Regimes at Al Baha Region, KSA  [PDF]
Abdulaziz Yahya Al-Ghamdi
American Journal of Climate Change (AJCC) , 2017, DOI: 10.4236/ajcc.2017.64031
Abstract: This study was conducted to determine the effect of atmospheric air on soil health in pots involving the growth of pea under two soil moisture regimes. Twelve pots were treated with three air quality treatments of urban, suburban and rural sites. In situ soil respiration increased under urban and suburban while it decreased little under rural site atmospheric conditions. These data support the relationships between the number of microorganisms in soils and carbon dioxide fluxes. Microbial biomass, metabolic quotient and crop yields or biomass were found most sensitive indicators of soil quality, which significantly varied in response to air quality and soil moisture regimes. The soil microbial biomass, metabolic quotient, and basal respiration were the most practical quality index variables; however, when using only a single predicator, microbial biomass was the most sensitive indicator of the soil quality.
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