Search results for: Saleh B. Mohamed
1304 Using Crude Actinidin Protease Extract of Kiwifruit to Improve Some Quality Attributes of Awassi Rams Meats
Authors: Hatem H.Saleh
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The aim of the study was to examine the effect of different concentrations of crude actinidin enzyme extract from kiwifruit juice and distilled water on some quality attributes of Awassi rams meats. Twelve Awassi rams were divided into four groups, After exsanguinations of rams carcasses they were infused (10% body weight) with crude of actinidin enzyme extract of kiwifruit juice with 10 and 15% of extract, and other group was infused with distilled water and were compared with other groups a non infusion treatment which were acted as a control. Thereafter samples from two main muscles, namely longissimus dorsi (LD) and Semimembranosus (SM) of the carcasses was chilled then stored in freezing, until testing time . The results showed a decrease in the rate pH decline on LD and SM muscle which was measured at time (0, 3, 6, 9, 12, 24 hours) postmortem among different treatments, It also reported lower values of the rate pH on the LD and SM muscle during the first of 12 hrs postmortem. No significant differences of the rate internal meat temperature in LD and SM muscle were observed among treatments postmortem except decreased of internal meat temperature during 3 hours postmortem when treated with enzyme extract. The results recorded higher values of glycolysis rate (R-value) in LD and SM muscle when treated with enzyme extract. Treated LD and LM muscle samples with 10 and 15% of crude actinidin enzyme extract of kiwifruit juice led to improve water holding capacity and higher significant differences in total tyrosine/ tryptophan index (T.T/T) in LD and SM muscles comparison with treatment control. It could be concluded that extract of kiwifruit juice infusion is could be used to improve of meat tenderization.Keywords: extract of kiwifruit, decline of pH and Temperature , R-value, tyrosine / tryptophan index, sheep meat
Procedia PDF Downloads 5291303 Preserving Privacy in Workflow Delegation Models
Authors: Noha Nagy, Hoda Mokhtar, Mohamed El Sherkawi
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The popularity of workflow delegation models and the increasing number of workflow provenance-aware systems motivate the need for finding more strict delegation models. Such models combine different approaches for enhanced security and respecting workflow privacy. Although modern enterprises seek conformance to workflow constraints to ensure correctness of their work, these constraints pose a threat to security, because these constraints can be good seeds for attacking privacy even in secure models. This paper introduces a comprehensive Workflow Delegation Model (WFDM) that utilizes provenance and workflow constraints to prevent malicious delegate from attacking workflow privacy as well as extending the delegation functionalities. In addition, we argue the need for exploiting workflow constraints to improve workflow security models.Keywords: workflow delegation models, secure workflow, workflow privacy, workflow provenance
Procedia PDF Downloads 3251302 Using the Textbook to Promote Thinking Skills in Intermediate School EFL Classrooms in Saudi Arabia: An Analysis of the Tasks and an Exploration of Teachers' and Perceptions
Authors: Nurah Saleh Alfares
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An aim of TS in EFL is to help learners to understand how they learn, which could help them in using the target language with other learners in language classrooms, and in their social life. The early researchers have criticised the system of teaching methods in EFL applied in Saudi schools, as they claim that it does not produce students who are highly proficient in English. Some of them suggested that enhancing learners’ TS would help to improve the learners’ proficiency of using the EFL. The textbook in Saudi schools is the central material for teachers to follow in the EFL classroom. Thus, this study is investigating the main issues that could promote TS in Saudi EFL: the textbook and the teachers. The purposes of the study are: to find out the extent to which the tasks in the textbook have the potential to support teachers in promoting TS; to discover insights into the nature of classroom activities that teachers use to encourage TS from the textbook and to explore the teachers’ views on the role of the textbook in promoting TS in the English language. These aims will improve understanding of the connection between the potential of the textbook content and the participants’ theoretical knowledge and their teaching practice. The investigation employed research techniques including the following: (1) analysis of the textbook; (2) questionnaire for EFL teachers; (3) observation for EFL classroom; (4) interviews with EFL teachers. Analysis of the third intermediate grade textbook has been undertaken, and six EFL teachers from five intermediate schools were involved in the study. Data analysis revealed that 36.71 % of the tasks in the textbook could have the potential to promote TS, and 63.29 % of the tasks in the textbook could not have the potential to promote TS. Therefore, the result of the textbook analysis showed that the majority of the tasks do not have the potential to help teachers to promote TS. Although not all teachers of the observed lessons displayed behaviour helpful to promote TS, teachers, who presented potential TS tasks in their lesson encouraged learners’ interaction and students’ engagement more than teachers who presented tasks that did not have the potential to promote TS. Therefore, the result of the teachers’ data showed that having a textbook that has the potential to promote TS is not enough to develop teaching TS in Saudi EFL since teachers’ behaviour could make the task more or less productive.Keywords: English as a Foreign Language, metacognitive skills, textbook, thinking skills
Procedia PDF Downloads 1171301 Exponential Spline Solution for Singularly Perturbed Boundary Value Problems with an Uncertain-But-Bounded Parameter
Authors: Waheed Zahra, Mohamed El-Beltagy, Ashraf El Mhlawy, Reda Elkhadrawy
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In this paper, we consider singular perturbation reaction-diffusion boundary value problems, which contain a small uncertain perturbation parameter. To solve these problems, we propose a numerical method which is based on an exponential spline and Shishkin mesh discretization. While interval analysis principle is used to deal with the uncertain parameter, sensitivity analysis has been conducted using different methods. Numerical results are provided to show the applicability and efficiency of our method, which is ε-uniform convergence of almost second order.Keywords: singular perturbation problem, shishkin mesh, two small parameters, exponential spline, interval analysis, sensitivity analysis
Procedia PDF Downloads 2651300 The Influence of the Concentration and Temperature on the Rheological Behavior of Carbonyl-Methylcellulose
Authors: Mohamed Rabhi, Kouider Halim Benrahou
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The rheological properties of the carbonyl-methylcellulose (CMC), of different concentrations (25000, 50000, 60000, 80000 and 100000 ppm) and different temperatures were studied. We found that the rheological behavior of all CMC solutions presents a pseudo-plastic behavior, it follows the model of Ostwald-de Waele. The objective of this work is the modeling of flow by the CMC Cross model. The Cross model gives us the variation of the viscosity according to the shear rate. This model allowed us to adjust more clearly the rheological characteristics of CMC solutions. A comparison between the Cross model and the model of Ostwald was made. Cross the model fitting parameters were determined by a numerical simulation to make an approach between the experimental curve and those given by the two models. Our study has shown that the model of Cross, describes well the flow of "CMC" for low concentrations.Keywords: CMC, rheological modeling, Ostwald model, cross model, viscosity
Procedia PDF Downloads 3831299 Numerical Solution of 1-D Shallow Water Equations at Junction for Sub-Critical and Super-Critical Flow
Authors: Mohamed Elshobaki, Alessandro Valiani, Valerio Caleffi
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In this paper, we solve 1-D shallow water equation for sub-critical and super-critical water flow at junction. The water flow at junction has been studied for the last 50 years from the physical-hydraulic point of views and for numerical computations need more attention. For numerical simulation, we need to establish an inner boundary condition at the junction to avoid an oscillation which rise from the waves interactions at the junction. Indeed, we introduce a new boundary condition at the junction based on the mass conservation, total head, and the admissible wave relations between the flow parameters in the three branches to predict the water depths and discharges at the junction. These boundary conditions are valid for sub-critical flow and super-critical flow.Keywords: numerical simulation, junction flow, sub-critical flow, super-critical flow
Procedia PDF Downloads 4951298 An Incremental Refinement Approach to a Development of Dynamic Host Configuration Protocol (DHCP) Using Event-B
Authors: Rajaa Filali, Mohamed Bouhdadi
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This paper presents an incremental development of the Dynamic Host Configuration Protocol (DHCP) in Event-B. DHCP is widely used communication protocol, which provides a standard mechanism to obtain configuration parameters. The specification is performed in a stepwise manner and verified through a series of refinements. The Event-B formal method uses the Rodin platform to modeling and verifying some properties of the protocol such as safety, liveness and deadlock freedom. To model and verify the protocol, we use the formal technique Event-B which provides an accessible and rigorous development method. This interaction between modelling and proving reduces the complexity and helps to eliminate misunderstandings, inconsistencies, and specification gaps.Keywords: DHCP protocol, Event-B, refinement, proof obligation, Rodin
Procedia PDF Downloads 2211297 Contribution in Fatigue Life Prediction of Composite Material
Authors: Mostefa Bendouba, Djebli Abdelkader, Abdelkrim Aid, Mohamed Benguediab
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The damage evolution mechanism is one of the important focuses of fatigue behaviour investigation of composite materials and also is the foundation to predict fatigue life of composite structures for engineering application. This paper is dedicated to a damage investigation under two block loading cycle fatigue conditions submitted to composite material. The loading sequence effect and the influence of the cycle ratio of the first stage on the cumulative fatigue life were studied herein. Two loading sequences, i.e., high-to-low and low-to-high cases are considered in this paper. The proposed damage indicator is connected cycle by cycle to the S-N curve and the experimental results are in agreement with model expectations. Some experimental researches are used to validate this proposition.Keywords: fatigue, damage acumulation, composite, evolution
Procedia PDF Downloads 4921296 Variation in Wood Anatomical Properties of Acacia seyal var. seyal Tree Species Growing in Different Zones in Sudan
Authors: Hanadi Mohamed Shawgi Gamal, Ashraf Mohamed Ahmed Abdalla
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Sudan is endowed by a great diversity of tree species; nevertheless, the utilization of wood resources has traditionally concentrated on a few number of species. With the great variation in the climatic zones of Sudan, great variations are expected in the anatomical properties between and within species. This variation needs to be fully explored in order to suggest the best uses for the species. Modern research on wood has substantiated that the climatic condition where the species grow has significant effect on wood properties. Understanding the extent of variability of wood is important because the uses for each kind of wood are related to its characteristics; furthermore, the suitability or quality of wood for a particular purpose is determined by the variability of one or more of these characteristics. The present study demonstrates the effect of rainfall zones in some anatomical properties of Acacia seyal var. seyal growing in Sudan. For this purpose, twenty healthy trees were collected randomly from two zones (ten trees per zone). One zone with relatively low rainfall (273mm annually) which represented by North Kordofan state and White Nile state and the second with relatively high rainfall (701 mm annually) represented by Blue Nile state and South Kordofan state. From each sampled tree, a stem disc (3 cm thick) was cut at 10% from stem height. One radius was obtained in central stem dices. Two representative samples were taken from each disc, one at 10% distance from pith to bark, the second at 90% in order to represent the juvenile and mature wood. The investigated anatomical properties were fibers length, fibers and vessels diameter, lumen diameter, and wall thickness as well as cell proportions. The result of the current study reveals significant differences between zones in mature wood vessels diameter and wall thickness, as well as juvenile wood vessels, wall thickness. The higher values were detected in the drier zone. Significant differences were also observed in juvenile wood fiber length, diameter as well as wall thickness. Contrary to vessels diameter and wall thickness, the fiber length, diameter as well as wall thickness were decreased in the drier zone. No significant differences have been detected in cell proportions of juvenile and mature wood. The significant differences in some fiber and vessels dimension lead to expect significant differences in wood density. From these results, Acacia seyal var. seyal seems to be well adapted with the change in rainfall and may survive in any rainfall zone.Keywords: Acacia seyal var. seyal, anatomical properties, rainfall zones, variation
Procedia PDF Downloads 1391295 Physico-Chemical Properties of Silurian Hot Shale in Ahnet Basin, Algeria: Case Study Well ASS-1
Authors: Mohamed Mehdi Kadri
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The prediction of hot shale interval in Silurian formation in a well drilled vertically in Ahnet basin Is by logging Data (Resistivity, Gamma Ray, Sonic) with the calculation of total organic carbon (TOC) using ∆ log R Method. The aim of this paper is to present Physico-chemical Properties of Hot Shale using IR spectroscopy and gas chromatography-mass spectrometry analysis; this mixture of measurements, evaluation and characterization show that the hot shale interval located in the lower of Silurian, the molecules adsorbed at the surface of shale sheet are significantly different from petroleum hydrocarbons this result are also supported with gas-liquid chromatography showed that the study extract is a hydroxypropyl.Keywords: physic-chemical analysis, reservoirs characterization, sweet window evaluation, Silurian shale, Ahnet basin
Procedia PDF Downloads 901294 Production of Ultra-Low Temperature by the Vapor Compression Refrigeration Cycles with Environment Friendly Working Fluids
Authors: Sameh Frikha, Mohamed Salah Abid
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We investigate the performance of an integrated cascade (IC) refrigeration system which uses environment friendly zeotropic mixtures. Computational calculation has been carried out by varying pressure level at the evaporator and the condenser of the system. Effects of mass flow rate of the refrigerant on the coefficient of performance (COP) are presented. We show that the integrated cascade system produces ultra-low temperatures in the evaporator by using environment friendly zeotropic mixture.Keywords: coefficient of performance, environment friendly zeotropic mixture, integrated cascade, ultra low temperature, vapor compression refrigeration cycles
Procedia PDF Downloads 2511293 Seroprevalence Study of Cystic Echinococcosis and Its Associated Risk Factors in Fars Province, Southern Iran
Authors: Mahmoud Reza Tahamtan, Mohammad Saleh Bahreini
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Background and Purpose: Cystic echinococcosis, caused by the larval stage of Echinococcus granulosus, is a common parasitic infection of humans and is endemic in many parts of the world, including Iran. So that, one percent of those admitted to surgery departments are hydatid cyst patients, and using the ELISA method, the infection rate has been reported in different regions of Iran from 1.2% to 21.4%. Therefore, the aim of this study was to investigate the seroepidemiology of human hydatid cysts in Fars province, southern Iran, by ELISA method. Methods: In this cross-sectional study, 600 serum samples of persons who were referred to the laboratory of Nemazi Hospital in Shiraz for normal tests were examined for the presence of specific Anti-IgG antibodies to hydatid cysts by ELISA method. During the sampling, a structured questionnaire was used to obtain social data of individuals with determinants of risk factors for Cystic echinococcosis. Finally, the results of the ELISA test, along with demographic information completed by individuals, were analyzed using SPSS software. Results: The average age of the subjects in this study was 40.01 ± 9.166. The prevalence of hydatidosis was reported as 5.66% (34/600). The disease was more in the age group of 21-30, people living in villages, working in rural areas, and people with a history of other parasitic diseases. Statistically, a significant difference was observed between the prevalence of the disease and two risk factors, contact with dogs (OR= 0.042; 95%CI: 0.014-0.12; P= 0.001) and washing vegetables with water (OR= 0.08; 95%CI: 0.011-0.56; P= 0.012). Conclusion: The present study showed that hydatid cyst disease has a significant prevalence in this area. Also, based on the results, contact with dogs and not properly washing vegetables are two important factors of disease transmission.Keywords: Echinococcus granulosus, Cystic echinococcosis, hydatid cyst, Fars province
Procedia PDF Downloads 861292 Influence of Rainfall Intensity on Infiltration and Deformation of Unsaturated Soil Slopes
Authors: Bouziane Mohamed Tewfik
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In order to improve the understanding of the influence of rainfall intensity on infiltration and deformation behaviour of unsaturated soil slopes, numerical 2D analyses are carried out by a three phase elasto-viscoplastic seepage-deformation coupled method. From the numerical results, it is shown that regardless of the saturated permeability of the soil slope, the increase in the pore water pressure (reduction in suction) during rainfall infiltration is localized close to the slope surface. In addition, the generation of the pore water pressure and the lateral displacement are mainly controlled by the ratio of the rainfall intensity to the saturated permeability of the soil.Keywords: unsaturated soil, slope stability, rainfall infiltration, numerical analysis
Procedia PDF Downloads 4571291 Theoretical Evaluation of the Effect of Solvent on the Feasibility of the Reaction of 2-Chlorobenzimidazole With Four N,N′-Cyclic Azomethine Imines to Construct Polycyclic Benzimidazoles
Authors: Mohamed Abdoul-Hakim, A. Zeroual, H. Garmes
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In this work, we theoretically evaluated the reactivity of four 4-methyl-3-oxo-1,2-pyrazolidinium ylides with 2-Chlorobenzimidazole in MeOH in basic medium using DFT at the B3LYP/6-311+G(d,p) level. The analysis of the results shows that apart from its ability to retain its electrons, the deprotonated 2-Chlorobenzimidazole has a higher nucleophilic character. The reaction requires energy input to initiate the nucleophilic attack of the 2-Chlorobenzimidazole anion, and the inclusion of the solvent effect facilitates the formation of two regioisomers via an intramolecular vinyl nucleophilic substitution (SNVi). The transition states of this latter step are stabilized by charge transfer interactions σ(N-C) →σ*(C-Cl) for the more favorable regioisomer and n(N)→σ*(C-Cl) for the other regioisomer.Keywords: benzonitrile N-oxide, DFT, intramolecular vinyl nucleophilic substitution (SNVi), 4-methyl-3-OXO-1, 2-pyrazolidinium ylides
Procedia PDF Downloads 1321290 The Role of Education (Tarbiyyah) in the Religio-Political Organization
Authors: Muhaimin Bin Sulam, Abdul Mutalib Embong, Azelin Mohamed Noor
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This paper presents the reinvention of the role of education (tarbiyyah) in the social influence of organizations focusing on the sustainability of a specific religio-political organization. The objective of the paper is to describe how the position secured by education could transform the organization while maintaining its objective and vision. The study employed the qualitative approach that involves data from conducted interviews. An analysis on the role political leaders play in educating the organization in the context of ideological struggle is also analyzed. The process description also evaluates how education could intellectualize its followers and members which inspires them to submit to their leaders and the organization. This extensive cultivation of religio-political doctrine could offer a new interpretation on politics.Keywords: religiopolitical organization, Malaysia, education (Tarbiyyah), followers, political movement
Procedia PDF Downloads 4771289 A Method to Saturation Modeling of Synchronous Machines in d-q Axes
Authors: Mohamed Arbi Khlifi, Badr M. Alshammari
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This paper discusses the general methods to saturation in the steady-state, two axis (d & q) frame models of synchronous machines. In particular, the important role of the magnetic coupling between the d-q axes (cross-magnetizing phenomenon), is demonstrated. For that purpose, distinct methods of saturation modeling of dumper synchronous machine with cross-saturation are identified, and detailed models synthesis in d-q axes. A number of models are given in the final developed form. The procedure and the novel models are verified by a critical application to prove the validity of the method and the equivalence between all developed models is reported. Advantages of some of the models over the existing ones and their applicability are discussed.Keywords: cross-magnetizing, models synthesis, synchronous machine, saturated modeling, state-space vectors
Procedia PDF Downloads 4421288 Modeling of Hydrogen Production by Inductively Coupled Methane Plasma for Input Power Pin=700W
Authors: Abdelatif Gadoum, Djilali Benyoucef, Mouloudj Hadj, Alla Eddine Toubal Maamar, Mohamed Habib Allah Lahoual
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Hydrogen occurs naturally in the form of chemical compounds, most often in water and hydrocarbons. The main objective of this study is 2D modeling of hydrogen production in inductively coupled plasma in methane at low pressure. In the present model, we include the motions and the collisions of both neutral and charged particles by considering 19 species (i.e in total ; neutrals, radicals, ions, and electrons), and more than 120 reactions (electron impact with methane, neutral-neutral, neutral-ions and surface reactions). The results show that the rate conversion of methane reach 90% and the hydrogen production is about 30%.Keywords: hydrogen production, inductively coupled plasma, fluid model, methane plasma
Procedia PDF Downloads 1501287 Weak Mutually Unbiased Bases versus Mutually Unbiased Bases in Terms of T-Designs
Authors: Mohamed Shalaby, Yasser Kamal, Negm Shawky
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Mutually unbiased bases (MUBs) have an important role in the field of quantum computation and information. A complete set of these bases can be constructed when the system dimension is the power of the prime. Constructing such complete set in composite dimensions is still an open problem. Recently, the concept of weak mutually unbiased bases (WMUBs) in composite dimensions was introduced. A complete set of such bases can be constructed by combining the MUBs in each subsystem. In this paper, we present a comparative study between MUBs and WMUBs in the context of complex projective t-design. Explicit proofs are presented.Keywords: complex projective t-design, finite quantum systems, mutually unbiased bases, weak mutually unbiased bases
Procedia PDF Downloads 4351286 The Effects of Expanding the Generosity of the Statutory Sick Leave Insurance: The Case of a French Reform
Authors: Mohamed Ali Benhalima, Nathon Elbaz, Malik Koubi
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This paper evaluates an expansion of employer-mandated sick leave insurance in the French private sector. We use a difference-in-differences method in which control groups are defined according to the collective bargaining agreement (CBA) employees belong to. Indeed, thanks to complementary insurance provided by CBAs, employees were not affected the same way by the reform. We find significant effects of the reform on sick leave spells lasting at least 7 days, consistently with the reform target. The effects on spells’ duration and frequency are positive and more pronounced for women than for men, for whom the effect on frequency tends to be slightly negative. The effects are also more pronounced for executives and supervisors than less qualified categories.Keywords: sickness absence, collective agreements, daily sickness benefits, labor economics
Procedia PDF Downloads 3391285 Adsorption of Phenol and 4-Hydroxybenzoic Acid onto Functional Materials
Authors: Mourad Makhlouf, Omar Bouchher, Messabih Sidi Mohamed, Benrachedi Khaled
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The objective of this study was to investigate the removal of two organic pollutants; 4-hydroxybenzoic acid (p-hydroxybenzoic acid) and phenol from synthetic wastewater by the adsorption on mesoporous materials. In this context, the aim of this work is to study the adsorption of organic compounds phenol and 4AHB on MCM-41 and FSM-16 non-grafted (NG) and other grafted (G) by trimethylchlorosilane (TMCS). The results of phenol and 4AHB adsorption in aqueous solution show that the adsorption capacity tends to increase after grafting in relation to the increase in hydrophobicity. The materials are distinguished by a higher adsorption capacity to the other NG materials. The difference in the phenol is 14.43% (MCM-41), 14.55% (FSM-16), and 16.72% (MCM-41), 13.57% (FSM-16) in the 4AHB. Our adsorption results show that the grafted materials by TMCS are good adsorbent at 25 °C.Keywords: MCM-41, FSM-16, TMCS, phenol, 4AHB
Procedia PDF Downloads 2571284 An Application-Driven Procedure for Optimal Signal Digitization of Automotive-Grade Ultrasonic Sensors
Authors: Mohamed Shawki Elamir, Heinrich Gotzig, Raoul Zoellner, Patrick Maeder
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In this work, a methodology is presented for identifying the optimal digitization parameters for the analog signal of ultrasonic sensors. These digitization parameters are the resolution of the analog to digital conversion and the sampling rate. This is accomplished through the derivation of characteristic curves based on Fano inequality and the calculation of the mutual information content over a given dataset. The mutual information is calculated between the examples in the dataset and the corresponding variation in the feature that needs to be estimated. The optimal parameters are identified in a manner that ensures optimal estimation performance while preventing inefficiency in using unnecessarily powerful analog to digital converters.Keywords: analog to digital conversion, digitization, sampling rate, ultrasonic
Procedia PDF Downloads 1961283 Inverse Heat Transfer Analysis of a Melting Furnace Using Levenberg-Marquardt Method
Authors: Mohamed Hafid, Marcel Lacroix
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This study presents a simple inverse heat transfer procedure for predicting the wall erosion and the time-varying thickness of the protective bank that covers the inside surface of the refractory brick wall of a melting furnace. The direct problem is solved by using the Finite-Volume model. The melting/solidification process is modeled using the enthalpy method. The inverse procedure rests on the Levenberg-Marquardt method combined with the Broyden method. The effect of the location of the temperature sensors and of the measurement noise on the inverse predictions is investigated. Recommendations are made concerning the location of the temperature sensor.Keywords: melting furnace, inverse heat transfer, enthalpy method, levenberg–marquardt method
Procedia PDF Downloads 3141282 Fabrication Methodologies for Anti-Microbial Polypropylene Surfaces with Leachable and Non-leachable Anti-Microbial Agents
Authors: Saleh Alkarri, Dimple Sharma, Teresa M. Bergholz, Muhammad Rabnawaz
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Aims: Develop a methodology for the fabrication of anti-microbial polypropylene (PP) surfaces with (i) leachable copper, (II) chloride dihydrate (CuCl₂·₂H₂O) and (ii) non-leachable magnesium hydroxide (Mg(OH)₂) biocides. Methods and Results: Two methodologies are used to develop anti-microbial PP surfaces. One method involves melt-blending and subsequent injection molding, where the biocide additives were compounded with PP and subsequently injection-molded. The other method involves the thermal embossing of anti-microbial agents on the surface of a PP substrate. The obtained biocide-bearing PP surfaces were evaluated against E. coli K-12 MG1655 for 0, 4, and 24 h to evaluate their anti-microbial properties. The injection-molded PP bearing 5% CuCl2·₂H₂O showed a 6-log reduction of E. coli K-12 MG1655 after 24 h, while only 1 log reduction was observed for PP bearing 5% Mg(OH)2. The thermally embossed PP surfaces bearing CuCl2·2H2O and Mg(OH)₂ particles (at a concentration of 10 mg/mL) showed 3 log and 4 log reduction, respectively, against E.coli K-12 MG1655 after 24 h. Conclusion: The results clearly demonstrate that CuCl₂·2H₂O conferred anti-microbial properties to PP surfaces that were prepared by both injection molding as well as thermal embossing approaches owing to the presence of leachable copper ions. In contrast, the non-leachable Mg(OH)₂ imparted anti-microbial properties only to the surface prepared via the thermal embossing technique. Significance and Impact of The Study: Plastics with leachable biocides are effective anti-microbial surfaces, but their toxicity is a major concern. This study provides a fabrication methodology for non-leachable PP-based anti-microbial surfaces that are potentially safer. In addition, this strategy can be extended to many other plastics substrates.Keywords: anti-microbial activity, E. coli K-12 MG1655, copper (II) chloride dihydrate, magnesium hydroxide, leachable, non-leachable, compounding, thermal embossing
Procedia PDF Downloads 701281 Fabrication Methodologies for Anti-microbial Polypropylene Surfaces with Leachable and Non-leachable Anti-microbial Agents
Authors: Saleh Alkarri, Dimple Sharma, Teresa M. Bergholz, Muhammad Rabnawa
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Aims: Develop a methodology for the fabrication of anti-microbial polypropylene (PP) surfaces with (i) leachable copper (II) chloride dihydrate (CuCl2·2H2O) and (ii) non-leachable magnesium hydroxide (Mg(OH)2) biocides. Methods and Results: Two methodologies are used to develop anti-microbial PP surfaces. One method involves melt-blending and subsequent injection molding, where the biocide additives were compounded with PP and subsequently injection-molded. The other method involves the thermal embossing of anti-microbial agents on the surface of a PP substrate. The obtained biocide-bearing PP surfaces were evaluated against E. coli K-12 MG1655 for 0, 4, and 24 h to evaluate their anti-microbial properties. The injection-molded PP bearing 5% CuCl2·2H2O showed a 6-log reduction of E. coli K-12 MG1655 after 24 h, while only 1 log reduction was observed for PP bearing 5% Mg(OH)2. The thermally embossed PP surfaces bearing CuCl2·2H2O and Mg(OH)2 particles (at a concentration of 10 mg/mL) showed 3 log and 4 log reduction, respectively, against E.coli K-12 MG1655 after 24 h. Conclusion: The results clearly demonstrate that CuCl2·2H2O conferred anti-microbial properties to PP surfaces that were prepared by both injection molding as well as thermal embossing approaches owing to the presence of leachable copper ions. In contrast, the non-leachable Mg(OH)2 imparted anti-microbial properties only to the surface prepared via the thermal embossing technique. Significance and Impact of The Study: Plastics with leachable biocides are effective anti-microbial surfaces, but their toxicity is a major concern. This study provides a fabrication methodology for non-leachable PP-based anti-microbial surfaces that are potentially safer. In addition, this strategy can be extended to many other plastics substrates.Keywords: anti-microbial activity, E. coli K-12 MG1655, copper (II) chloride dihydrate, magnesium hydroxide, leachable, non-leachable, compounding, thermal embossing
Procedia PDF Downloads 731280 Photocatalytic Degradation of Phenol by Fe-Doped Tio2 under Solar Simulated Light
Authors: Mohamed Gar Alalm, Shinichi Ookawara, Ahmed Tawfik
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In the present work, photocatalytic oxidation of phenol by iron (Fe+2) doped titanium dioxide (TiO2) was studied. The source of irradiation was solar simulated light under measured UV flux. The effect of light intensity, pH, catalyst loading, and initial concentration of phenol were investigated. The maximum removal of phenol at optimum conditions was 78%. The optimum pH was 5.3. The most effective degradation occurred when the catalyst dosage was 600 mg/L. increasing the initial concentration of phenol decreased the degradation efficiency due to the deactivation of active sites by additional intermediates. Phenol photocatalytic degradation moderately fitted to the pseudo-first order kinetic equation approximated from Langmuir–Hinshelwood model.Keywords: phenol, photocatalytic, solar, titanium dioxide
Procedia PDF Downloads 3911279 Selection of Endophytcs Fungi Isolated from Date Palm, Halotolerants and Productors of Secondary Metabolite
Authors: Fadila Mohamed Mahmoud., Derkaoui I., Krimi Z.
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Date palm is a plant which presents a very good adaptation to the difficult conditions of the environment in particular to the drought and saline stress even at high temperatures. This adaptation is related on the biology of the plant and to the presence of a microflora endophyte which live inside its tissues. Fifteen endophytics fungi isolated from date palm were tested in vitro in the presence of various NaCl concentrations to select halotolerantes isolates. These same endophytes were tested for their colonizing capacity by the description of the production of secondary metabolites more particularly the enzymes (pectinases, proteases, and phosphorylases), and the production of antibiotics and growth hormones. Significant difference was observed between the isolates with respect to the tests carried out.Keywords: Date palm, Halotolerantes, endophyte, Secondary metabolites.
Procedia PDF Downloads 5111278 The Kafrah Dam (The Oldest Dam in History)
Authors: Mohamed Bekhit Gad Khalil
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This dam is the oldest dam in history. It was built by the ancient Egyptian around (2650 B.C) control flooding. It is believed to have been built between the third and fourth dynasties .It contains the oldest dam in history. Many studies have been conducted for the dam. This report was prepared under my supervision and in cooperation with the Ministry of Tourism and Antiquities. The dam was re-documented and photographed again. The dam on the northern side Consists of irregularly shaped stones of varying sizes used randomly. Sand and soil fill the gaps between the stones. creating layers to form the body of the dam. The eastern. side of the dam Consists of a series of regular shaped stones that have been cut and constructed into a stepped pyramid-like structure with width of (15,7) meters and height of (10) meters. The surface has significant erosion and wear on the stones due to weather Conditions. which has resulted in deep cavities in most of the stone blocks forming the surface.Keywords: ministry of tourism and antiquities, excavations, registration, documentation
Procedia PDF Downloads 241277 Biodegradation of Cellulosic Materials by Marine Fungi Isolated from South Corniche of Jeddah, Saudi Arabia
Authors: Fuad Ameen, Mohamed Moslem, Sarfaraz Hadi
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Twenty-eight fungal isolates belonging to 12 genera were derived from debris, sediment and water samples collected from Avicennia marina stands 25km south of Jeddah city on the Red Sea coast of Saudi Arabia. Eight of these isolates were found to be able to grow in association cellulosic waste materials under in vitro conditions in the absence of any carbon source. Isolates were further tested for their potential to degrade paper and clothes wastes by co-cultivation under aeration on a rotary shaker. These fungi accumulated significantly higher biomass, produced ligninolytic and cellulase enzymes, and liberated larger volumes of CO2. These observations indicated that the selected isolates were able to break down and consume the waste materials.Keywords: biodegradation, enzyme activity, waste materials, mangrove
Procedia PDF Downloads 5501276 Effect of Fuel Type on Design Parameters and Atomization Process for Pressure Swirl Atomizer and Dual Orifice Atomizer for High Bypass Turbofan Engine
Authors: Mohamed K. Khalil, Mohamed S. Ragab
Abstract:
Atomizers are used in many engineering applications including diesel engines, petrol engines and spray combustion in furnaces as well as gas turbine engines. These atomizers are used to increase the specific surface area of the fuel, which achieve a high rate of fuel mixing and evaporation. In all combustion systems reduction in mean drop size is a challenge which has many advantages since it leads to rapid and easier ignition, higher volumetric heat release rate, wider burning range and lower exhaust concentrations of the pollutant emissions. Pressure atomizers have a different configuration for design such as swirl atomizer (simplex), dual orifice, spill return, plain orifice, duplex and fan spray. Simplex pressure atomizers are the most common type of all. Among all types of atomizers, pressure swirl types resemble a special category since they differ in quality of atomization, the reliability of operation, simplicity of construction and low expenditure of energy. But, the disadvantages of these atomizers are that they require very high injection pressure and have low discharge coefficient owing to the fact that the air core covers the majority of the atomizer orifice. To overcome these problems, dual orifice atomizer was designed. This paper proposes a detailed mathematical model design procedure for both pressure swirl atomizer (Simplex) and dual orifice atomizer, examines the effects of varying fuel type and makes a clear comparison between the two types. Using five types of fuel (JP-5, JA1, JP-4, Diesel and Bio-Diesel) as a case study, reveal the effect of changing fuel type and its properties on atomizers design and spray characteristics. Which effect on combustion process parameters; Sauter Mean Diameter (SMD), spray cone angle and sheet thickness with varying the discharge coefficient from 0.27 to 0.35 during takeoff for high bypass turbofan engines. The spray atomizer performance of the pressure swirl fuel injector was compared to the dual orifice fuel injector at the same differential pressure and discharge coefficient using Excel. The results are analyzed and handled to form the final reliability results for fuel injectors in high bypass turbofan engines. The results show that the Sauter Mean Diameter (SMD) in dual orifice atomizer is larger than Sauter Mean Diameter (SMD) in pressure swirl atomizer, the film thickness (h) in dual orifice atomizer is less than the film thickness (h) in pressure swirl atomizer. The Spray Cone Angle (α) in pressure swirl atomizer is larger than Spray Cone Angle (α) in dual orifice atomizer.Keywords: gas turbine engines, atomization process, Sauter mean diameter, JP-5
Procedia PDF Downloads 1571275 Implantology Failure: Epidemiological Survey among Tunisian Dentists
Authors: Faten Khanfir, Mohamed Tlili, Ali Medeb Hamrouni, Raki Selmi, M. S. Khalfi, Faten Ben Amor
Abstract:
Introduction: dental implant failure is a major concern for the clinician and the patient. Objectives: The aim of our study is to investigate the way in which 100 Tunisian dentists carried implant treatment for their patients from the early phase of planning and selection of patients to the placement of the implant in order to look for the implant failure factors. Results: significant correlations were found between failure rates > 5 and their corresponding factors as the number of implants placed (p = 0.001<0, 05), smoking (0.046 <0.05), unbalanced diabetes (0.03<0.05), aseptic protocol (= 0.004< 0.05) and the drilling speed (0,002<0.05) Conclusion: It seems that the number of implant placed, smoking, diabetes, aseptic protocol, and the drilling speed may contribute to dental implant failure.Keywords: failure, implants, survey, risk, osseointegration
Procedia PDF Downloads 170