Search results for: Heba Shafik Ibrahim Mohamed
1775 Small Wind Turbine Hybrid System for Remote Application: Egyptian Case Study
Authors: M. A. Badr, A. N. Mohib, M. M. Ibrahim
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The objective of this research is to study the technical and economic performance of wind/diesel/battery (W/D/B) system supplying a remote small gathering of six families using HOMER software package. The electrical energy is to cater for the basic needs for which the daily load pattern is estimated. Net Present Cost (NPC) and Cost of Energy (COE) are used as economic criteria, while the measure of performance is % of power shortage. Technical and economic parameters are defined to estimate the feasibility of the system under study. Optimum system configurations are estimated for two sites. Using HOMER software, the simulation results showed that W/D/B systems are economical for the assumed community sites as the price of generated electricity is about 0.308 $/kWh, without taking external benefits into considerations. W/D/B systems are more economical than W/B or diesel alone systems, as the COE is 0.86 $/kWh for W/B and 0.357 $/kWh for diesel alone.Keywords: optimum energy systems, remote electrification, renewable energy, wind turbine systems
Procedia PDF Downloads 4021774 Interfacing and Replication of Electronic Machinery Using MATLAB/SIMULINK
Authors: Abdulatif Abdulsalam, Mohamed Shaban
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This paper introduces interfacing and replication of electronic tools based on the MATLAB/ SIMULINK mock-up package. Mock-up components contain dc-dc converters, power issue rectifiers, motivation machines, dc gear, synchronous gear, and more entire systems. Power issue rectifier model includes solid state device models. The tools are the clear-cut structure and mock-up of complex energetic systems connecting with power electronic machines.Keywords: power electronics, machine, MATLAB, simulink
Procedia PDF Downloads 3571773 Preparation and Characterization of Nanocrystalline Cellulose from Acacia mangium
Authors: Samira Gharehkhani, Seyed Farid Seyed Shirazi, Abdolreza Gharehkhani, Hooman Yarmand, Ahmad Badarudin, Rushdan Ibrahim, Salim Newaz Kazi
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Nanocrystalline cellulose (NCC) were prepared by acid hydrolysis and ultrasound treatment of bleached Acacia mangium fibers. The obtained rod-shaped nanocrystals showed a uniform size. The results showed that NCC with high crystallinity can be obtained using 64 wt% sulfuric acid. The effect of synthesis condition was investigated. Different reaction times were examined to produce the NCC and the results revealed that an optimum reaction time has to be used for preparing the NCC. Morphological investigation was performed using the transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were performed. X-ray diffraction (XRD) analysis revealed that the crystallinity increased with successive treatments. The NCC suspension was homogeneous and stable and no sedimentation was observed for a long time.Keywords: acid hydrolysis, nanocrystalline cellulose, nano material, reaction time
Procedia PDF Downloads 5051772 Optimization Process for Ride Quality of a Nonlinear Suspension Model Based on Newton-Euler’ Augmented Formulation
Authors: Mohamed Belhorma, Aboubakar S. Bouchikhi, Belkacem Bounab
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This paper addresses modeling a Double A-Arm suspension, a three-dimensional nonlinear model has been developed using the multibody systems formalism. Dynamical study of the different components responses was done, particularly for the wheel assembly. To validate those results, the system was constructed and simulated by RecurDyn, a professional multibody dynamics simulation software. The model has been used as the Objectif function in an optimization algorithm for ride quality improvement.Keywords: double A-Arm suspension, multibody systems, ride quality optimization, dynamic simulation
Procedia PDF Downloads 1381771 Journals' Productivity in the Literature on Malaria in Africa
Authors: Yahya Ibrahim Harande
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The purpose of this study was to identify the journals that published articles on malaria disease in Africa and to determine the core of productive journals from the identified journals. The data for the study were culled out from African Index Medicus (AIM) database. A total of 529 articles was gathered from 115 journal titles from 1979-2011. In order to obtain the core of productive journals, Bradford`s law was applied to the collected data. Five journal titles were identified and determined as core journals. The data used for the study was analyzed and that, the subject matter used, Malaria was in conformity with the Bradford`s law. On the aspect dispersion of the literature, English was found to be the dominant language of the journals. (80.9%) followed by French (16.5%). Followed by Portuguese (1.7%) and German (0.9%). Recommendation is hereby proposed for the medical libraries to acquire these five journals that constitute the core in malaria literature for the use of their clients. It could also help in streamlining their acquision and selection exercises. More researches in the subject area using Bibliometrics approaches are hereby recommended.Keywords: productive journals, malaria disease literature, Bradford`s law, core journals, African scholars
Procedia PDF Downloads 3451770 Study the Dynamic Behavior of Irregular Buildings by the Analysis Method Accelerogram
Authors: Beciri Mohamed Walid
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Some architectural conditions required some shapes often lead to an irregular distribution of masses, rigidities and resistances. The main object of the present study consists in estimating the influence of the irregularity both in plan and in elevation which presenting some structures on the dynamic characteristics and his influence on the behavior of this structures. To do this, it is necessary to make apply both dynamic methods proposed by the RPA99 (spectral modal method and method of analysis by accelerogram) on certain similar prototypes and to analyze the parameters measuring the answer of these structures and to proceed to a comparison of the results.Keywords: structure, irregular, code, seismic, method, force, period
Procedia PDF Downloads 3101769 Flame Acceleration of Premixed Natural Gas/Air Explosion in Closed Pipe
Authors: H. Mat Kiah, Rafiziana M. Kasmani, Norazana Ibrahim, Roshafima R. Ali, Aziatul N.Sadikin
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An experimental study has been done to investigate the flame acceleration in a closed pipe. A horizontal steel pipe, 2m long and 0.1 m in diameter (L/D of 20), was used in this work. For tests with 90 degree bends, the bend had a radius of 0.1 m and thus, the pipe was lengthened 1 m (based on the centreline length of the segment). Ignition was affected one end of the vessel while the other end was closed. Only stoichiometric concentration (Ф, = 1.0) of natural gas/air mixtures will be reported in this paper. It was demonstrated that bend pipe configuration gave three times higher in maximum over-pressure (5.5 bars) compared to straight pipe (2.0 bars). From the results, the highest flame speed of 63 m s-1 was observed in a gas explosion with bent pipe, greater by a factor of ~3 as compared with straight pipe (23 m s-1). This occurs because bending acts similar to an obstacle, in which this mechanism can induce more turbulence, initiating combustion in an unburned pocket at the corner region and causing a high mass burning rate which increases the flame speed.Keywords: bending, gas explosion, bending, flame acceleration, over-pressure
Procedia PDF Downloads 4091768 Evolution of Deformation in the Southern Central Tunisian Atlas: Parameters and Modelling
Authors: Mohamed Sadok Bensalem, Soulef Amamria, Khaled Lazzez, Mohamed Ghanmi
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The southern-central Tunisian Atlas presents a typical example of an external zone. It occupies a particular position in the North African chains: firstly, it is the eastern limit of atlassic structures; secondly, it is the edges between the belts structures to the north and the stable Saharan platform in the south. The evolution of deformation study is based on several methods, such as classical or numerical methods. The principals parameters controlling the genesis of folds in the southern central Tunisian Atlas are; the reactivation of pre-existing faults during the later compressive phase, the evolution of decollement level, and the relation between thin and thick-skinned. One of the more principal characters of the southern-central Tunisian Atlas is the variation of belts structures directions determined by: NE-SW direction, named the attlassic direction in Tunisia, the NW-SE direction carried along the Gafsa fault (the oriental limit of southern atlassic accident), and the E-W direction defined in the southern Tunisian Atlas. This variation of direction is the result of important variation of deformation during different tectonics phases. A classical modelling of the Jebel ElKebar anticline, based on faults throw of the pre-existing faults and its reactivation during compressive phases, shows the importance of extensional deformation, particular during Aptian-Albian period, comparing with that of later compression (Alpine phases). A numerical modelling, based on the software Rampe E.M. 1.5.0, applied on the anticline of Jebel Orbata confirms the interpretation of “fault related fold” with decollement level within the Triassic successions. The other important parameter of evolution of deformation is the vertical migration of decollement level; indeed, more than the decollement level is in the recent series, most that the deformation is accentuated. The evolution of deformation is marked the development of duplex structure in Jebel At Taghli (eastern limit of Jebel Orbata). Consequently, the evolution of deformation is proportional to the depth of the decollement level, the most important deformation is in the higher successions; thus, is associated to the thin-skinned deformation; the decollement level permit the passive transfer of deformation in the cover.Keywords: evolution of deformation, pre-existing faults, decollement level, thin-skinned
Procedia PDF Downloads 1261767 The Pragmatics of the Evil Eye: Compliment Response Strategies in Egyptian Colloquial Arabic
Authors: HebatAllah Mohamed
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The present study aims at identifying compliment response strategies used by Egyptian students when responding to a problematic and cultural-specific type of compliments: those allegedly provoking the evil eye. Discourse Completion Tasks (DCTs) and interviews were used to collect the data. both The participants were 21 female and 16 male Egyptian graduate and undergraduate students at the American university in Cairo. The results revealed a number of both common and different main and sub-categories of responses utilized by participants of both genders. Pedagogical implications are discussed.Keywords: Arabic pragmatics, compliment responses, evil eye pragmatics, pragmatics in Egypt
Procedia PDF Downloads 4891766 Towards a Simulation Model to Ensure the Availability of Machines in Maintenance Activities
Authors: Maryam Gallab, Hafida Bouloiz, Youness Chater, Mohamed Tkiouat
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The aim of this paper is to present a model based on multi-agent systems in order to manage the maintenance activities and to ensure the reliability and availability of machines just with the required resources (operators, tools). The interest of the simulation is to solve the complexity of the system and to find results without cost or wasting time. An implementation of the model is carried out on the AnyLogic platform to display the defined performance indicators.Keywords: maintenance, complexity, simulation, multi-agent systems, AnyLogic platform
Procedia PDF Downloads 3051765 The Origins of Inflation in Tunisia
Authors: Narimen Rdhaounia Mohamed Kouni
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Our aim in this paper is to identify the origins of inflation in Tunisia on the period from 1988 to 2018. In order to estimate the model, an ARDL methodology is used. We studied also the effect of informal economy on inflation. Indeed, we estimated the size of the informal economy in Tunisia based on Gutmann method. The results showed that there are three main origins of inflation. In fact, the first origin is the fiscal policy adopted by Tunisia, particularly after revolution. The second origin is the increase of monetary variables. Finally, informal economy played an important role in inflation.Keywords: inflation, consumer price index, informal, gutmann method, ARDL model
Procedia PDF Downloads 821764 Risk Measure from Investment in Finance by Value at Risk
Authors: Mohammed El-Arbi Khalfallah, Mohamed Lakhdar Hadji
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Managing and controlling risk is a topic research in the world of finance. Before a risky situation, the stakeholders need to do comparison according to the positions and actions, and financial institutions must take measures of a particular market risk and credit. In this work, we study a model of risk measure in finance: Value at Risk (VaR), which is a new tool for measuring an entity's exposure risk. We explain the concept of value at risk, your average, tail, and describe the three methods for computing: Parametric method, Historical method, and numerical method of Monte Carlo. Finally, we briefly describe advantages and disadvantages of the three methods for computing value at risk.Keywords: average value at risk, conditional value at risk, tail value at risk, value at risk
Procedia PDF Downloads 4411763 The Utilization of Particle Swarm Optimization Method to Solve Nurse Scheduling Problem
Authors: Norhayati Mohd Rasip, Abd. Samad Hasan Basari , Nuzulha Khilwani Ibrahim, Burairah Hussin
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The allocation of working schedule especially for shift environment is hard to fulfill its fairness among them. In the case of nurse scheduling, to set up the working time table for them is time consuming and complicated, which consider many factors including rules, regulation and human factor. The scenario is more complicated since most nurses are women which have personnel constraints and maternity leave factors. The undesirable schedule can affect the nurse productivity, social life and the absenteeism can significantly as well affect patient's life. This paper aimed to enhance the scheduling process by utilizing the particle swarm optimization in order to solve nurse scheduling problem. The result shows that the generated multiple initial schedule is fulfilled the requirements and produces the lowest cost of constraint violation.Keywords: nurse scheduling, particle swarm optimisation, nurse rostering, hard and soft constraint
Procedia PDF Downloads 3721762 Study the Multifaceted Therapeutic Properties of the IQGAP1shRNA Plasmid on Rat Liver Cancer Model
Authors: Khairy M. A. Zoheir, Nehma A. Ali, Ahmed M. Darwish, Mohamed S. Kishta, Ahmed A. Abd-Rabou, Mohamed A. Abdelhafez, Karima F. Mahrous
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The study comprehensively investigated the multifaceted therapeutic properties of the IQGAP1shRNA plasmid, encompassing its hepatoprotective, immunomodulatory, and anticancer activities. The study employed a Prednisolone-induced immunosuppressed rat model to assess the hepatoprotective and immunomodulatory effects of IQGAP1shRNA plasmid. Using this model, IQGAP1shRNA plasmid was found to modulate haematopoiesis, improving RBC, platelet, and WBC counts, underscoring its potential in hematopoietic homeostasis. Organ atrophy, a hallmark of immunosuppression in spleen, heart, liver, ovaries, and kidneys, was reversed with IQGAP1shRNA plasmid treatment, reinforcing its hepatotrophic and organotropic capabilities. Elevated hepatic biomarkers (ALT, AST, ALP, LPO) indicative of hepatocellular injury and oxidative stress were reduced with GST, highlighting its hepatoprotective and antioxidative effects. IQGAP1shRNA plasmid also restored depleted antioxidants (GSH and SOD), emphasizing its potent antioxidative and free radical scavenging capabilities. Molecular insights into immune dysregulation revealed downregulation of IQGAP1, IQGAP3 interleukin-2 (IL-2), and interleukin-4 (IL-4) mRNA expression in the liver of immunosuppressed rats. IL-2 and IL-4 play pivotal roles in immune regulation, T-cell activation, and B-cell differentiation. Notably, treatment with IQGAP1shRNA plasmid exhibited a significant upregulation of IL-2 and IL-4 mRNA expression, thereby accentuating its immunomodulatory potential in orchestrating immune homeostasis. Additionally, immune dysregulation was associated with increased levels of TNF-α. However, treatment with IQGAP1shRNA plasmid effectively decreased the levels of TNF-α, further underscoring its role in modulating inflammatory responses and restoring immune balance in immunosuppressed rats. Additionally, pharmacokinetics, bioavailability, drug-likeness, and toxicity risk assessment prediction suggest its potential as a pharmacologically favourable agent with no serious adverse effects. In conclusion, this study confirms the therapeutic potential of the IQGAP1shRNA plasmid, showcasing its effectiveness against hepatotoxicity, oxidative stress, immunosuppression, and its notable anticancer activity.Keywords: IQGAP1, shRNA, cancer, liver, rat
Procedia PDF Downloads 31761 Using Confirmatory Factor Analysis to Test the Dimensional Structure of Tourism Service Quality
Authors: Ibrahim A. Elshaer, Alaa M. Shaker
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Several previous empirical studies have operationalized service quality as either a multidimensional or unidimensional construct. While few earlier studies investigated some practices of the assumed dimensional structure of service quality, no study has been found to have tested the construct’s dimensionality using confirmatory factor analysis (CFA). To gain a better insight into the dimensional structure of service quality construct, this paper tests its dimensionality using three CFA models (higher order factor model, oblique factor model, and one factor model) on a set of data collected from 390 British tourists visited Egypt. The results of the three tests models indicate that service quality construct is multidimensional. This result helps resolving the problems that might arise from the lack of clarity concerning the dimensional structure of service quality, as without testing the dimensional structure of a measure, researchers cannot assume that the significant correlation is a result of factors measuring the same construct.Keywords: service quality, dimensionality, confirmatory factor analysis, Egypt
Procedia PDF Downloads 5911760 Sustainability with Health: A Daylighting Approach
Authors: Mohamed Boubekri
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Daylight in general and sunlight in particular are vital to life on earth, and it is not difficult to believe that their absence fosters conditions that promote disease. Through photosynthesis and other processes, sunlight provides photochemical ingredients necessary for our lives. There are fundamental biological, hormonal, and physiological functions coordinated by cycles that are crucial to life for cells, plants, animals, and humans. Many plants and animals, including humans, develop abnormal behaviors when sunlight is absent because their diurnal cycle is disturbed. Building codes disregard this aspect of daylighting when promulgating windows for buildings. This paper discusses the health aspects of daylighting design.Keywords: daylighting, health, sunlight, sleep, disorders, circadian rythm, cancer
Procedia PDF Downloads 3371759 Empirical Model for the Estimation of Global Solar Radiation on Horizontal Surface in Algeria
Authors: Malika Fekih, Abdenour Bourabaa, Rafika Hariti, Mohamed Saighi
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In Algeria the global solar radiation and its components is not available for all locations due to which there is a requirement of using different models for the estimation of global solar radiation that use climatological parameters of the locations. Empirical constants for these models have been estimated and the results obtained have been tested statistically. The results show encouraging agreement between estimated and measured values.Keywords: global solar radiation, empirical model, semi arid areas, climatological parameters
Procedia PDF Downloads 5021758 Seamless Mobility in Heterogeneous Mobile Networks
Authors: Mohab Magdy Mostafa Mohamed
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The objective of this paper is to introduce a vertical handover (VHO) algorithm between wireless LANs (WLANs) and LTE mobile networks. The proposed algorithm is based on the fuzzy control theory and takes into consideration power level, subscriber velocity, and target cell load instead of only power level in traditional algorithms. Simulation results show that network performance in terms of number of handovers and handover occurrence distance is improved.Keywords: vertical handover, fuzzy control theory, power level, speed, target cell load
Procedia PDF Downloads 3521757 Analysis of Suitability of Online Assessment by Maintaining Critical Thinking
Authors: Mohamed Chabi
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The purpose of this study is to determine Whether paper assessment especially in the subject mathematics will ever be completely replaced by online assessment using Learning Management System and Content Management System such as blackboard. In the subject mathematics, the assessment is the exercise of judgment on the quality of students’ work, as a way of supporting student learning and appraising its outcomes. Testing students has moved from the traditional scribbling and sketching on paper towards working online on a screen and keyboard.Keywords: paper assessment, online assessment, learning management system, content management system, mathematics
Procedia PDF Downloads 4681756 Hydrometallurgical Treatment of Abu Ghalaga Ilmenite Ore
Authors: I. A. Ibrahim, T. A. Elbarbary, N. Abdelaty, A. T. Kandil, H. K. Farhan
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The present work aims to study the leaching of Abu Ghalaga ilmenite ore by hydrochloric acid and simultaneous reduction by iron powder method to dissolve its titanium and iron contents. Iron content in the produced liquor is separated by solvent extraction using TBP as a solvent. All parameters affecting the efficiency of the dissolution process were separately studied including the acid concentration, solid/liquid ratio which controls the ilmenite/acid molar ratio, temperature, time and grain size. The optimum conditions at which maximum leaching occur are 30% HCl acid with a solid/liquid ratio of 1/30 at 80 °C for 4 h using ore ground to -350 mesh size. At the same time, all parameters affecting on solvent extraction and stripping of iron content from the produced liquor were studied. Results show that the best extraction is at solvent/solution 1/1 by shaking at 240 RPM for 45 minutes at 30 °C whereas best striping of iron at H₂O/solvent 2/1.Keywords: ilmenite ore, leaching, titanium solvent extraction, Abu Ghalaga ilmenite ore
Procedia PDF Downloads 2901755 Comparison between Classical and New Direct Torque Control Strategies of Induction Machine
Authors: Mouna Essaadi, Mohamed Khafallah, Abdallah Saad, Hamid Chaikhy
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This paper presents a comparative analysis between conventional direct torque control (C_DTC), Modified direct torque control (M_DTC) and twelve sectors direct torque control (12_DTC).Those different strategies are compared by simulation in term of torque, flux and stator current performances. Finally, a summary of the comparative analysis is presented.Keywords: C_DTC, M_DTC, 12_DTC, torque dynamic, stator current, flux, performances
Procedia PDF Downloads 6191754 Measuring Sustainable Interior Design
Authors: Iman Ibrahim
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The interest of this paper is to review the sustainability measuring tools in Interior Design in UAE. To examine the ability of creating sustainable interior designed buildings satisfying the community social culture needs related to the world eco systems and how much it’s affected by humans, as the research will focus on sustainability as a multi-dimensional concept including environmental, social and economic dimensions. The aim of this research is to reach the most suitable sustainable rating method criteria for buildings in UAE, in a trial to develop it to match the community culture. Developing such criteria is gaining significance in UAE as a result of increased awareness of the environmental, economic and social issues. This will allow an exploration of the suitable criteria for developing a sustainable rating method for buildings in UAE. The final research findings will be presented as suitable criteria for developing a sustainable building assessment method for UAE in terms of environmental, economic, social and cultural perspectives.Keywords: rating methods, sustainability tools, UAE, local conditions
Procedia PDF Downloads 4191753 Students’ Perceptions on Educational Game for Learning Programming Subject: A Case Study
Authors: Roslina Ibrahim, Azizah Jaafar, Khalili Khalil
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Educational games (EG) are regarded as a promising teaching and learning tool for the new generation. Growing number of studies and literatures can be found in EG studies. Both academic researchers and commercial developers come out with various educational games prototypes and titles. Despite that, acceptance of educational games still lacks among the students. It is important to understanding students’ perceptions of EG, since they are the main stakeholder of the technology. Thus, this study seeks to understand perceptions of undergraduates’ students using a framework originated from user acceptance theory. The framework consists of six constructs with twenty-eight items. Data collection was done on 180 undergraduate students of Universiti Teknologi Malaysia, Kuala Lumpur using self-developed online EG called ROBO-C. Data analysis was done using descriptive, factor analysis and correlations. Performance expectancy, effort expectancy, attitude, and enjoyment factors were found significantly correlated with the intention to use EG. This study provides more understanding towards the use of educational games among students.Keywords: educational games, perceptions, acceptance, UTAUT
Procedia PDF Downloads 4111752 SOTM: A New Cooperation Based Trust Management System for VANET
Authors: Amel Ltifi, Ahmed Zouinkhi, Mohamed Salim Bouhlel
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Security and trust management in Vehicular Ad-hoc NETworks (VANET) is a crucial research domain which is the scope of many researches and domains. Although, the majority of the proposed trust management systems for VANET are based on specific road infrastructure, which may not be present in all the roads. Therefore, road security should be managed by vehicles themselves. In this paper, we propose a new Self Organized Trust Management system (SOTM). This system has the responsibility to cut with the spread of false warnings in the network through four principal components: cooperation, trust management, communication and security.Keywords: ative vehicle, cooperation, trust management, VANET
Procedia PDF Downloads 4301751 A Primer to the Learning Readiness Assessment to Raise the Sharing of E-Health Knowledge amongst Libyan Nurses
Authors: Mohamed Elhadi M. Sharif, Mona Masood
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The usage of e-health facilities is seen to be the first priority by the Libyan government. As such, this paper focuses on how the key factors or elements of working size in terms of technological availability, structural environment, and other competence-related matters may affect nurses’ sharing of knowledge in e-health. Hence, this paper investigates learning readiness assessment to raise e-health for Libyan regional hospitals by using e-health services in nursing education.Keywords: Libyan nurses, e-learning readiness, e-health, nursing education
Procedia PDF Downloads 4931750 Investigating the Nail Walls Performance in Jointed Rock Medium
Authors: Ibrahim Naeimifar, Omid Naeemifar
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Evaluation of the excavation-induced ground movements is an important design aspect of support systems in urban areas. Geological and geotechnical conditions of an excavation area have significant effects on excavation-induced ground movements and the related damage. This paper is aimed at studying the performance of excavation walls supported by nails in jointed rock medium. The performance of nailed walls is investigated based on evaluating the excavation-induced ground movements. For this purpose, a set of calibrated 2D finite element models is developed by taking into account the nail-rock-structure interactions, the anisotropic properties of jointed rock, and the staged construction process. The results of this paper highlight effects of different parameters such as joint inclinations, the anisotropy of rocks and nail inclinations on deformation parameters of excavation wall supported by nails.Keywords: finite element, jointed rock, nailing, performance
Procedia PDF Downloads 2881749 Numerical and Experimental Investigation of the Aerodynamic Performances of Counter-Rotating Rotors
Authors: Ibrahim Beldjilali, Adel Ghenaiet
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The contra-rotating axial machine is a promising solution for several applications, where high pressure and efficiencies are needed. Also, they allow reducing the speed of rotation, the radial spacing and a better flexibility of use. However, this requires a better understanding of their operation, including the influence of second rotor on the overall aerodynamic performances. This work consisted of both experimental and numerical studies to characterize this counter-rotating fan, especially the analysis of the effects of the blades stagger angle and the inter-distance between the rotors. The experimental study served to validate the computational fluid dynamics model (CFD) used in the simulations. The numerical study permitted to cover a wider range of parameter and deeper investigation on flow structures details, including the effects of blade stagger angle and inter-distance, associated with the interaction between the rotors. As a result, there is a clear improvement in aerodynamic performance compared with a conventional machine.Keywords: aerodynamic performance, axial fan, counter rotating rotors, CFD, experimental study
Procedia PDF Downloads 1591748 Ophthalmic Services Covered by Albasar International Foundation in Sudan
Authors: Mohammad Ibrahim
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The study was conducted at Albasar international foundation ophthalmic hospitals in Sudan to study the burden and patterns of ophthalmic disorder in the sector. Review of the hospitals records revealed that the total number of patient examined in the hospitals and outreached camps conducted by the hospitals is 10,513,874, the total number of surgeries is 694,015 and the total number of pupils at school program is 230,382. The organization working with the highest management system and standards and quality result based planning. The study yielded that the ophthalmic problem in Sudan are of great percentage and the temporal blindness disorder are high since major cases and surgeries were Cataract (57.8%). Retinal problem (2.9%), Glaucoma (2.4%), Orbit and Occulo-plastic disorders (2.2%) other disorders are refractive errors, squint and strabismus, Corneal, Pediatrics and minor ophthalmic disorders.Keywords: hospitals and outreach ophthalmic services, largest coverage of ophthalmic services, nonprofitable ophthalmic services, strong management system and standards
Procedia PDF Downloads 4101747 Sequential Covering Algorithm for Nondifferentiable Global Optimization Problem and Applications
Authors: Mohamed Rahal, Djaouida Guetta
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In this paper, the one-dimensional unconstrained global optimization problem of continuous functions satifying a Hölder condition is considered. We extend the algorithm of sequential covering SCA for Lipschitz functions to a large class of Hölder functions. The convergence of the method is studied and the algorithm can be applied to systems of nonlinear equations. Finally, some numerical examples are presented and illustrate the efficiency of the present approach.Keywords: global optimization, Hölder functions, sequential covering method, systems of nonlinear equations
Procedia PDF Downloads 3691746 The Influence of Sulfate and Magnesium Ions on the Growth Kinetics of CaCO3
Authors: Kotbia Labiod, Mohamed Mouldi Tlili
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The presence of different mineral salts in natural waters may precipitate and form hard deposits in water distribution systems. In this respect, we have developed numerous works on scaling by Algerian water with a very high hardness of 102 °F. The aim of our work is to study the influence of water dynamics and its composition on mineral salts on the precipitation of calcium carbonate (CaCO3). To achieve this objective, we have adopted two precipitation techniques based on controlled degassing of dissolved CO2. This study will identify the causes and provide answers to this complex phenomenon.Keywords: calcium carbonate, controlled degassing, precipitation, scaling
Procedia PDF Downloads 233