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Search Results: 1 - 10 of 372 matches for " Amine Marref "
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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
Jahn–Teller Effect, Crystal Structure and High Temperature Raman Spectroscopy Studies of Ba2-xSrxCuWO6 (0 ≤ x≤ 2) Double Perovskite Oxide.  [PDF]
Amine Ezzahi, Abdellah Elmchaouri
Advances in Materials Physics and Chemistry (AMPC) , 2014, DOI: 10.4236/ampc.2014.44009
Abstract:

The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that there are conflicts of interests among the authors. The scientific community takes a very strong view on this matter, and the Advances in Materials Physics and Chemistry treats all unethical behaviors seriously. This paper published in Vol. 4 No. 4 61-74, 2014 has been removed from this site.

Title: JahnTeller Effect, Crystal Structure and High Temperature Raman Spectroscopy Studies of Ba2-xSrxCuWO6 (0 x 2) Double Perovskite Oxide.

Authors: Amine Ezzahi, Abdellah Elmchaouri


Income Disparities: The Case of Unskilled Workers in Canada (1996-2010)  [PDF]
Samir Amine, Phillippe Scrimger
Theoretical Economics Letters (TEL) , 2015, DOI: 10.4236/tel.2015.51011
Abstract: In this paper we analyse the gaps in economic welfare that exist between skilled and unskilled labor in Canada. Following the work of Chardon [1] [2]?and Amossé and Chardon [3], we use compe- tency levels as defined in the National Classification of Occupations to distinguish these two groups and then analyse the income disparities that exist between them. Our main findings show that unskilled workers are worse off economically than their skilled counterparts and that the Canadian workforce seems to be more bipolarized than the Canadian population as a whole. We also find strong intra-categorical inequalities within unskilled labor, workers from the sales and services occupational domain being at a disadvantage relative to their peers in other occupational groups. Finally, we show that state intervention, through taxation and social transfers, plays an important role in tightening the inter-categorical and intra-categorical income gaps.
Integration of Occupational Health and Safety into Lean Manufacturing: Quebec Aeronautics Case Study  [PDF]
Amine Sakouhi, Sylvie Nadeau
American Journal of Industrial and Business Management (AJIBM) , 2016, DOI: 10.4236/ajibm.2016.611097
Abstract: The literature remains divided the ideal conditions for integration of occupational health and safety (OHS) into continuous improvement initiatives based on the principles of lean manufacturing. Few significant results and little documentation exist on the effectiveness, sustainability and the degree of integration. This paper outlines some possible explanations for the non-success of this integration and examines the hypothesis that integration is unsuccessful when the lean-based improvements themselves suffer from sustainability issues. This research project addressed the case of a Québec manufacturing company and focused on musculoskeletal injury (MSI). Twenty-four employees participated in the study for two months. Corporate documentation was analyzed. Individual interviews were used to document workers’ perception of their work environment. Continuous improvement interventions were observed to identify possible risks of MSI, and obtain a general portrait of OHS and continuous improvement in this company. The majority of the employees surveyed believed that the continuous improvement initiatives were short-lived. They also reported they experienced MSI-related discomfort following organizational changes. Examination of several initiatives showed that results were not maintained over time. The integration of OHS into continuous improvement is not systematic. When this integration is apparent, OHS goals are not always met and are rarely subject to monitoring. Taking OHS into consideration, implementing lean principles does not directly guarantee a reduction in cases of MSI. The integration of OHS into continuous improvement activities is reflected in the systematic consideration of OHS in driving lean improvements. The results of this project will help to develop a better approach to the implementation of lean to improve this integration in our industries.
Updating Genetics Polymorphisms of Non-Syndromic Clefts Lip-Palates  [PDF]
Amine Rafik, Sellama Nadifi
American Journal of Molecular Biology (AJMB) , 2018, DOI: 10.4236/ajmb.2018.83015
Abstract:
Introduction: Non-Syndromic Clefts Lip-Palates (NSCLP/CP) are most common congenital malformation in the world, with very important psychic and social impact. Formation of NSCLP/CP arises from the interaction of environmental and genetic factors. This paper provides a review of recent progress in defining the genetic causes of NSCLP. Methods: A literature review was conducted on the Medline data by searching for the following keywords: genes, non-syndromic cleft lip-palate, and genetics of clefts lip-palates, until January 2018. Results: Various genes are identified in different population and country, with the study using case parent’s trio. The aim of this study contributes to review relative gene which has been identify in non-syndromic cleft lip and palate, and to help to have a better understanding of the inheritance pattern of this pathology and the prevention of genetic disease. Conclusion: Although three major genes have been confirmed, the genetic research is necessary to provide an understanding of the pathophysiology of the clefts lip-palates.
Highly Efficient Extraction of Cadmium(II) in Nitrate Medium by Quarternary Ammoniums  [PDF]
Brahim Guezzen, Mohamed Amine Didi
American Journal of Analytical Chemistry (AJAC) , 2015, DOI: 10.4236/ajac.2015.611085
Abstract: The solvent extraction of cadmium(II) from nitrate medium was studied. The using extractants were quaternary ammonium-based room temperature ionic liquid Aliquat 336 in either the chloride [(C8H17)3 CH3N+·Cl-], thiocyanate [(C8H17)3CH3N+·SCN-] and hydrogenophosphate \"\" forms, diluted in the kerosene. The effects of different parameters such as equilibration time, initial pH, O/A molar ratio (nextractant/nCd), initial extractant concentration and ionic strong on extraction of cadmium(II) were investigated. The extraction yields of cadmium(II) increase with increasing initial pH and initial extractant concentration. The stoichiometry of the extracted species was determined on the basis of slope analysis. The effect of various salts such as KSCN and NaNO3 in the feed solution within the concentrations of 10 to 100 mM on extraction of cadmium(II) was studied at optimal initial pH = 6.2. The relation between the percentages of the extracted species (\"\") and the extraction yields were investigated by a calculation program using CHEAQS V. L20.1. The results showed that the decrease of the extraction yield of Cd(II) was related with the decrease gradually of percentage of cadmium(II) free and the increase of percentage of\"\" and \"\" species with the addition of KSCN. More the hydrophobic character of the extractant is high, more the extraction is better. The metal ion was stripped out satisfactorily using nitric acid as stripping agent, in one step.
What is the Criterion for a Strong First Order Electroweak Phase Transition in Singlet Models?
Ahriche, Amine
High Energy Physics - Phenomenology , 2007, DOI: 10.1103/PhysRevD.75.083522
Abstract: It is widely believed that the existence of singlet scalars in some Standard Model extensions can easily make the electroweak phase transition strongly first order, which is needed for the electroweak baryogenesis scenario. In this paper, we will examine the strength of the electroweak phase transition in the simplest extension of the Standard Model with a real singlet using the sphaleron energy at the critical temperature. We find that the phase transition is stronger by adding a singlet; and also that the criterion for a strong phase transition Omega (Tc)/Tc>1, where Omega =(v^2+(x-x0)^2)^(1/2) and x (x0) is the singlet vev in the broken (symmetric) phase, is not valid for models containing singlets, even though often used in the literature. The usual condition vc/Tc>1 is more meaningful, and it is satisfied for a large part of the parameter space for physically allowed Higgs masses.
Comparing Risk Neutral Density Estimation Methods using Simulated Option Data
Amine Bouden
Lecture Notes in Engineering and Computer Science , 2007,
Abstract:
On f(R) Theories Equivalent To General Relativity For Spacetimes With Constant Ricci Scalar
Amine Benachour
Physics , 2012,
Abstract: We prove the necessary and the sufficient condition on the function f(R) leading to the equivalence of general relativity and the f(R) theory in the sense that for a spacetime with constant Ricci scalar, GR and the f(R) theory generated by any f(R) function satisfying this condition will necessarily have the same solutions. We show how this condition and its consequences allow to get such functions and give the possibility to fixe conditions on the parameters of any class of f(R) functions so that GR and this class of theories will have exactly the same solutions. The well-known model R+{\alpha}\b{eta}^{1-p}R^{p} for dark energy is presented as an illustration.
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