Search results for: Ahmed M. Mansour
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1699

Search results for: Ahmed M. Mansour

1129 Improvement on a CNC Gantry Machine Structure Design for Higher Machining Speed Capability

Authors: Ahmed A. D. Sarhan, S. R. Besharaty, Javad Akbaria, M. Hamdi

Abstract:

The capability of CNC gantry milling machines in manufacturing long components has caused the expanded use of such machines. On the other hand, the machines’ gantry rigidity can reduce under severe loads or vibration during operation. Indeed, the quality of machining is dependent on the machine’s dynamic behavior throughout the operating process. For this reason, this type of machines has always been used prudently and are non efficient. Therefore, they can usually be employed for rough machining and may not produce adequate surface finishing. In this paper, a CNC gantry milling machine with the potential to produce good surface finish has been designed and analyzed. The lowest natural frequency of this machine is 202 Hz at all motion amplitudes with a full range of suitable frequency responses. Meanwhile, the maximum deformation under dead loads for the gantry machine is 0.565µm, indicating that this machine tool is capable of producing higher product quality.

Keywords: frequency response, finite element, gantry machine, gantry design, static and dynamic analysis

Procedia PDF Downloads 357
1128 Sliding Mode Controller for Active Suspension System on a Passenger Car Model

Authors: Nouby M. Ghazaly, Ahmed O. Moaaz, Mostafa Makrahy

Abstract:

The main purpose of a car suspension system is to reduce the vibrations resulting from road roughness. The main objective of this research paper is to decrease vibration and improve passenger comfort through controlling car suspension system using sliding mode control techniques. The mathematical model for passive and active suspensions systems for quarter car model which subject to excitation from different road profiles is obtained. The active suspension system is synthesized based on sliding mode control for a quarter car model. The performance of the sliding mode control is determined through computer simulations using MATLAB and SIMULINK toolbox. The simulated results plotted in time domain, and root mean square values. It is found that active suspension system using sliding mode control improves the ride comfort and decrease vibration.

Keywords: quarter car model, active suspension system, sliding mode control, road profile

Procedia PDF Downloads 309
1127 Mechanism for Network Security via Routing Protocols Estimated with Network Simulator 2 (NS-2)

Authors: Rashid Mahmood, Muhammad Sufyan, Nasir Ahmed

Abstract:

The MANETs have lessened transportation and decentralized network. There are numerous basis of routing protocols. We derived the MANETs protocol into three major categories like Reactive, Proactive and hybrid. In these protocols, we discussed only some protocols like Distance Sequenced Distance Vector (DSDV), Ad hoc on Demand Distance Vector (AODV) and Dynamic Source Routing (DSR). The AODV and DSR are both reactive type of protocols. On the other hand, DSDV is proactive type protocol here. We compare these routing protocols for network security estimated by network simulator (NS-2). In this dissertation some parameters discussed such as simulation time, packet size, number of node, packet delivery fraction, push time and speed etc. We will construct all these parameters on routing protocols under suitable conditions for network security measures.

Keywords: DSDV, AODV, DSR NS-2, PDF, push time

Procedia PDF Downloads 433
1126 A Hybrid Recommendation System Based on Association Rules

Authors: Ahmed Mohammed Alsalama

Abstract:

Recommendation systems are widely used in e-commerce applications. The engine of a current recommendation system recommends items to a particular user based on user preferences and previous high ratings. Various recommendation schemes such as collaborative filtering and content-based approaches are used to build a recommendation system. Most of the current recommendation systems were developed to fit a certain domain such as books, articles, and movies. We propose a hybrid framework recommendation system to be applied on two-dimensional spaces (User x Item) with a large number of Users and a small number of Items. Moreover, our proposed framework makes use of both favorite and non-favorite items of a particular user. The proposed framework is built upon the integration of association rules mining and the content-based approach. The results of experiments show that our proposed framework can provide accurate recommendations to users.

Keywords: data mining, association rules, recommendation systems, hybrid systems

Procedia PDF Downloads 453
1125 Novel Steviosides Analogs Induced Apoptosis in Breast Cancers

Authors: Ahmed Malki

Abstract:

Breast cancer has been identified as the most lethal form of cancer today. In our study, we designed and screened 16 steviosides derivatives for their cytotoxic activities in MCF-7human breast cancer cells and normal MCF-12a cells. Our data indicated that steviosides derivatives 9 and 15 decreased cell proliferation and induced apoptosis in MCF-7 breast cancer cells more thannormal breast cells epithelial cells. Flow cytometric analysis showed that both steviosides, derivatives 9 and 15 arrested the MCF-7 cells in G1 phase, which is further confirmed by the increased expression level of p21. Moreover, both steviosides derivatives increased caspase-9 activity, and the induction of apoptosis was significantly reduced after treating cells with caspase-9 inhibitor LEHD-CHO. Both steviosides derivatives increased Caspase 3 activities and induced Parp-1 cleavage in H1299 cells. Based on previous results, we have identified two novel steviosides derivatives which provoked apoptosis in breast cancer cells by arresting cells in G1 phase and increasing caspase-9 and caspase-3 activities which merits further development and investigations.

Keywords: steviosides, breast cancer, p53, cell cycle

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1124 Fast Tumor Extraction Method Based on Nl-Means Filter and Expectation Maximization

Authors: Sandabad Sara, Sayd Tahri Yassine, Hammouch Ahmed

Abstract:

The development of science has allowed computer scientists to touch the medicine and bring aid to radiologists as we are presenting it in our article. Our work focuses on the detection and localization of tumors areas in the human brain; this will be a completely automatic without any human intervention. In front of the huge volume of MRI to be treated per day, the radiologist can spend hours and hours providing a tremendous effort. This burden has become less heavy with the automation of this step. In this article we present an automatic and effective tumor detection, this work consists of two steps: the first is the image filtering using the filter Nl-means, then applying the expectation maximization algorithm (EM) for retrieving the tumor mask from the brain MRI and extracting the tumor area using the mask obtained from the second step. To prove the effectiveness of this method multiple evaluation criteria will be used, so that we can compare our method to frequently extraction methods used in the literature.

Keywords: MRI, Em algorithm, brain, tumor, Nl-means

Procedia PDF Downloads 336
1123 Performance Analysis of the Time-Based and Periodogram-Based Energy Detector for Spectrum Sensing

Authors: Sadaf Nawaz, Adnan Ahmed Khan, Asad Mahmood, Chaudhary Farrukh Javed

Abstract:

Classically, an energy detector is implemented in time domain (TD). However, frequency domain (FD) based energy detector has demonstrated an improved performance. This paper presents a comparison between the two approaches as to analyze their pros and cons. A detailed performance analysis of the classical TD energy-detector and the periodogram based detector is performed. Exact and approximate mathematical expressions for probability of false alarm (Pf) and probability of detection (Pd) are derived for both approaches. The derived expressions naturally lead to an analytical as well as intuitive reasoning for the improved performance of (Pf) and (Pd) in different scenarios. Our analysis suggests the dependence improvement on buffer sizes. Pf is improved in FD, whereas Pd is enhanced in TD based energy detectors. Finally, Monte Carlo simulations results demonstrate the analysis reached by the derived expressions.

Keywords: cognitive radio, energy detector, periodogram, spectrum sensing

Procedia PDF Downloads 377
1122 HRCT of the Chest and the Role of Artificial Intelligence in the Evaluation of Patients with COVID-19

Authors: Parisa Mansour

Abstract:

Introduction: Early diagnosis of coronavirus disease (COVID-19) is extremely important to isolate and treat patients in time, thus preventing the spread of the disease, improving prognosis and reducing mortality. High-resolution computed tomography (HRCT) chest imaging and artificial intelligence (AI)-based analysis of HRCT chest images can play a central role in the treatment of patients with COVID-19. Objective: To investigate different chest HRCT findings in different stages of COVID-19 pneumonia and to evaluate the potential role of artificial intelligence in the quantitative assessment of lung parenchymal involvement in COVID-19 pneumonia. Materials and Methods: This retrospective observational study was conducted between May 1, 2020 and August 13, 2020. The study included 2169 patients with COVID-19 who underwent chest HRCT. HRCT images showed the presence and distribution of lesions such as: ground glass opacity (GGO), compaction, and any special patterns such as septal thickening, inverted halo, mark, etc. HRCT findings of the breast at different stages of the disease (early: andlt) 5 days, intermediate: 6-10 days and late stage: >10 days). A CT severity score (CTSS) was calculated based on the extent of lung involvement on HRCT, which was then correlated with clinical disease severity. Use of artificial intelligence; Analysis of CT pneumonia and quot; An algorithm was used to quantify the extent of pulmonary involvement by calculating the percentage of pulmonary opacity (PO) and gross opacity (PHO). Depending on the type of variables, statistically significant tests such as chi-square, analysis of variance (ANOVA) and post hoc tests were applied when appropriate. Results: Radiological findings were observed in HRCT chest in 1438 patients. A typical pattern of COVID-19 pneumonia, i.e., bilateral peripheral GGO with or without consolidation, was observed in 846 patients. About 294 asymptomatic patients were radiologically positive. Chest HRCT in the early stages of the disease mostly showed GGO. The late stage was indicated by such features as retinal enlargement, thickening and the presence of fibrous bands. Approximately 91.3% of cases with a CTSS = 7 were asymptomatic or clinically mild, while 81.2% of cases with a score = 15 were clinically severe. Mean PO and PHO (30.1 ± 28.0 and 8.4 ± 10.4, respectively) were significantly higher in the clinically severe categories. Conclusion: Because COVID-19 pneumonia progresses rapidly, radiologists and physicians should become familiar with typical TC chest findings to treat patients early, ultimately improving prognosis and reducing mortality. Artificial intelligence can be a valuable tool in treating patients with COVID-19.

Keywords: chest, HRCT, covid-19, artificial intelligence, chest HRCT

Procedia PDF Downloads 63
1121 Antibacterial Activity of Green Synthesis Silver Nanoparticles from Moringa Oleifera

Authors: Ali Fadhel Ahmed, Tuqa Abdulkareem Hameed

Abstract:

Moringa oleifera (leaves and seeds) ethanolic and aqueous extracts were tested for antibacterial activity. The effect of plant extracts on three types of bacterial species: Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae, was investigated. Using the agar well diffusion method, ethanolic extracts of Moringa oleifera demonstrated a significant antibacterial effect on the forty tested bacterial strains. Seed-induced inhibition zones (ethanolic extracts)were ranged from16 to 24 mm in diameter against S. aureus, respectively, whileE. coli and K. pneumonia had no effect. Gram-positive and Gram-negative bacteria were not affected by alcoholic and aqueous plant leaf extracts. The purpose of this present study was to look at the cytotoxic effects of M.Oleifera plant (alcoholic extracts).

Keywords: moringa oleifera, escherichia coli, klebsiella pneumoniae, staphylococcus aureus

Procedia PDF Downloads 159
1120 Treatment of Simulated Textile Wastewater Containing Reactive Azo Dyes Using Laboratory Scale Trickling Filter

Authors: Ayesha Irum, Sadia Mumtaz, Abdul Rehman, Iffat Naz, Safia Ahmed

Abstract:

The present study was conducted to evaluate the potential applicability of biological trickling filter system for the treatment of simulated textile wastewater containing reactive azo dyes with bacterial consortium under non-sterile conditions. The percentage decolorization for the treatment of wastewater containing structurally different dyes was found to be higher than 95% in all trials. The stable bacterial count of the biofilm on stone media of the trickling filter during the treatment confirmed the presence, proliferation, dominance and involvement of the added microbial consortium in the treatment of textile wastewater. Results of physicochemical parameters revealed the reduction in chemical oxygen demand (58.5-75.1%), sulphates (18.9-36.5%), and phosphates (63.6-73.0%). UV-Visible and FTIR spectroscopy confirmed decolorization of dye containing wastewater was the ultimate consequence of biodegradation. Toxicological studies revealed the nontoxic nature of degradative metabolites.

Keywords: biodegradation, textile dyes, waste water, trickling filters

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1119 Analysis of Brushless DC Motor with Trapezoidal Back EMF Using Matlab

Authors: Taha Ahmed Husain

Abstract:

The dynamic characteristics such as speed and torque as well as voltages and currents of pwm brushless DC motor inverter are analyzed with a MATLAB model. The contribution of external load torque and friction torque is monitored. The switching function technique is adopted for the current control of the embedded three phase inverter that drives the brushless DC motor.In switching functions the power conversions circuits can be modeled according to their functions rather than circuit topologies. Therefore, it can achieve simplification of the overall power conversion functions. The trapezoidal type (back emf) is used in the model as ithas lower switching loss compared with sinusoidal type (back emf). Results show reliable time analysis for speed, torque, phase and line voltages and currents and the effect of current commutation is clearly observed.

Keywords: BLDC motor, brushless dc motors, pwm inverter, DC motor control, trapezoidal back emf, ripple torque in brushless DC motor

Procedia PDF Downloads 598
1118 Integrated Model for Enhancing Data Security Processing Time in Cloud Computing

Authors: Amani A. Saad, Ahmed A. El-Farag, El-Sayed A. Helali

Abstract:

Cloud computing is an important and promising field in the recent decade. Cloud computing allows sharing resources, services and information among the people of the whole world. Although the advantages of using clouds are great, but there are many risks in a cloud. The data security is the most important and critical problem of cloud computing. In this research a new security model for cloud computing is proposed for ensuring secure communication system, hiding information from other users and saving the user's times. In this proposed model Blowfish encryption algorithm is used for exchanging information or data, and SHA-2 cryptographic hash algorithm is used for data integrity. For user authentication process a simple user-name and password is used, the password uses SHA-2 for one way encryption. The proposed system shows an improvement of the processing time of uploading and downloading files on the cloud in secure form.

Keywords: cloud computing, data security, SAAS, PAAS, IAAS, Blowfish

Procedia PDF Downloads 359
1117 Building a Lean Construction Body of Knowledge

Authors: Jyoti Singh, Ahmed Stifi, Sascha Gentes

Abstract:

The process of construction significantly contributes to high level of risks, complexity and uncertainties leading to cost and time overrun, customer dissatisfaction etc. lean construction is important as it is a comprehensive system of tools and concepts focusing on moving closer to customer satisfaction by understanding the process, identifying the waste and eliminating it. The proposed work includes identification of knowledge areas from lean perspective, lean tools/concepts used in lean construction and establishing a relationship matrix between knowledge areas and lean tools/concepts, thus developing and building up a lean construction body of knowledge (LCBOK), i.e. a guide to lean construction, aiming to provide guidelines to manage individual projects and also helping construction industry to minimise waste and maximize value to the customer. In this study, we identified 8 knowledge areas and 62 lean tools/concepts from lean perspective and also one tool can help to manage two or more knowledge areas.

Keywords: knowledge areas, lean body matrix, lean construction, lean tools

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1116 Towards a Secure Storage in Cloud Computing

Authors: Mohamed Elkholy, Ahmed Elfatatry

Abstract:

Cloud computing has emerged as a flexible computing paradigm that reshaped the Information Technology map. However, cloud computing brought about a number of security challenges as a result of the physical distribution of computational resources and the limited control that users have over the physical storage. This situation raises many security challenges for data integrity and confidentiality as well as authentication and access control. This work proposes a security mechanism for data integrity that allows a data owner to be aware of any modification that takes place to his data. The data integrity mechanism is integrated with an extended Kerberos authentication that ensures authorized access control. The proposed mechanism protects data confidentiality even if data are stored on an untrusted storage. The proposed mechanism has been evaluated against different types of attacks and proved its efficiency to protect cloud data storage from different malicious attacks.

Keywords: access control, data integrity, data confidentiality, Kerberos authentication, cloud security

Procedia PDF Downloads 335
1115 Yaw Angle Effect on the Aerodynamic Performance of Rear-Roof Spoiler of Hatchback Vehicle

Authors: See-Yuan Cheng, Kwang-Yhee Chin, Shuhaimi Mansor

Abstract:

Rear-roof spoiler is commonly used for improving the aerodynamic performance of road vehicles. This study aims to investigate the effect of yaw angle on the effectiveness of strip-type rear-roof spoiler in providing lower drag and lift coefficients of a hatchback model. A computational fluid dynamics (CFD) method was used. The numerically obtained results were compared to the experimental data for validation of the CFD method. At increasing yaw angle, both the drag and lift coefficients of the model were to increase. In addition, the effectiveness of spoiler was deteriorated. These unfavorable effects were due to the formation of longitudinal vortices around the side edges of the model that had caused the surface pressure of the model to drop. Furthermore, there were significant crossflow structures developed behind the model at larger yaw angle, which were associated with the drop in the surface pressure of the rear section of the model and cause the drag coefficient to rise.

Keywords: Ahmed model, aerodynamics, spoiler, yaw angle

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1114 The Arabian Financial Framework in the Pre-Islamic Times: Do We Need a New Paradigm

Authors: Fahad Ahmed Qureshi

Abstract:

There were abundant renowned financial markets in Pre-Islamic Arabs. Most of those were patterned and settled during pre-particularized sunshine. Those markets were classified either as vernacular markets helping the neighboring clans, or habitual markets that people sojourned to from all articulations of the Arabian Peninsula, such as Okaz near Mecca. Some of those markets had leading significance due to their geographical positions, such as Prime market of Eden, because of their entanglement in international trade i.e. with the markets of Sub-Continent, Abyssinia, Persia and China. Other markets such as Market of Yamamah annex its gist from being situated on the caravan crossroads. Islamic worldview and Islamic epistemology base of Financial Market’s realistic theory, pragmatic model and operative approach is moderately constrained in terms of its growth. The existent situation only parasol the form of accommodative-modification and splendid-methodologies, which due to depleted and decorous endeavor in explaining Islamic financial market theoretically. This is the demand of time that particular studies should be conduct to magnify the devours in developing theoretical framework for Islamic Financial Market.

Keywords: Islam, financial market, history, research, product development

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1113 Exploring Cardiovascular and Behavioral Impacts of Aerobic Exercise: A ‎Moroccan Perspective

Authors: Ahmed Boujdad

Abstract:

‎ Morocco, a North African nation known for its rich culture and diverse landscapes, is facing evolving challenges related to cardiovascular health and behavioral well-being. Against this backdrop, the paper aims to spotlight the insights emerging from Moroccan research into the impacts of aerobic exercise on cardiovascular physiology and psychological outcomes. Presentations will encompass a range of topics, including exercise-induced adaptations in heart function, blood pressure management, and vascular health specific to the Moroccan population. A notable focus of the paper will be the examination of how aerobic exercise intertwines with Moroccan behavioral patterns and sociocultural factors. The research will delve into the links between regular exercise and its potential to alleviate stress, anxiety, and depression in the Moroccan context. This exploration extends to the role of exercise in bolstering the cultural fabric of Moroccan society, enhancing community engagement, and promoting a sense of well-being.

Keywords: event-related potential‎, executive function, physical activity, kinesiology

Procedia PDF Downloads 82
1112 Simulation Study on Vehicle Drag Reduction by Surface Dimples

Authors: S. F. Wong, S. S. Dol

Abstract:

Automotive designers have been trying to use dimples to reduce drag in vehicles. In this work, a car model has been applied with dimple surface with a parameter called dimple ratio DR, the ratio between the depths of the half dimple over the print diameter of the dimple, has been introduced and numerically simulated via k-ε turbulence model to study the aerodynamics performance with the increasing depth of the dimples The Ahmed body car model with 25 degree slant angle is simulated with the DR of 0.05, 0.2, 0.3 0.4 and 0.5 at Reynolds number of 176387 based on the frontal area of the car model. The geometry of dimple changes the kinematics and dynamics of flow. Complex interaction between the turbulent fluctuating flow and the mean flow escalates the turbulence quantities. The maximum level of turbulent kinetic energy occurs at DR = 0.4. It can be concluded that the dimples have generated extra turbulence energy at the surface and as a result, the application of dimples manages to reduce the drag coefficient of the car model compared to the model with smooth surface.

Keywords: aerodynamics, boundary layer, dimple, drag, kinetic energy, turbulence

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1111 Production of Renewable and Clean Bio-Fuel (DME) from Biomethanol over Copper Modified Alumina Catalyst

Authors: Ahmed I. Osman, Jehad K. Abu-Dahrieh, David W. Rooney, Jillian Thompson

Abstract:

The effect of loading of copper on the catalytic performance of different alumina support during the dehydration of methanol to dimethyl ether (DME) was performed in a fixed bed reactor. There are two levels of loading; low loading (1, 2, 4 and 6% Cu wt/wt) and high loading (10 and 15% Cu wt/wt) on both AC350 (alumina catalyst calcined at 350) and AC550 (alumina catalyst calcined at 550), to study the effect of loading and the effect of the support during methanol dehydration to DME (MTD). The catalysts were characterized by TGA, XRD, BET, TPD-NH3, TEM and DRIFT-Pyridine. Under reaction conditions where the temperature ranged from 180-300˚C with a WHSV= 12.1 h-1 it was found that all the catalysts calcined at 550˚C showed higher activity than those calcined at 350˚C. In this study, the optimum catalyst was 6% Cu/AC550. This catalyst showed a high degree of stability, had one half activity of the pure catalyst (AC550) and double the activity of the optimum catalyst calcined at 350˚C (6% Cu/AC350). So, we recommended 6% Cu/AC550 for the production of DME from methanol.

Keywords: bio-fuel, nano composite catalyst, DME, Cu-Al2O3

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1110 Management of Organizational Behavior Utilizing Human Resources

Authors: Habab Ahmed Hassan Abuzeid

Abstract:

Organizations are social systems. If one wishes to work in them or to manage them, it is necessary to understand how they operate. Organizations combine science and people–technology and humanity. Unless we have qualified people to design and implement, techniques alone will not produce desirable results. Human behavior in organizations is rather unpredictable. It is unpredictable because it arises from people’s deep-seated needs and value systems. However, it can be partially understood in terms of the framework of behavioral science, management and other disciplines. There is no idealistic solution to organizational problems. All that can be done is to increase our understanding and skills so that human relations at work can be enhanced. In this paper, we consider management of organization behavior utilizing human resources. Study the elements of organization behavior, the effectiveness of mechanism to enhance staff relationships. Many approaches could be applied for healthy organizational environment, it’s highlighted more details in this paper. Organization behavior can raise the employees’ engagement, loyalty and commitment; to accomplish the goal.

Keywords: environment, engagement, human resources, organization behavior

Procedia PDF Downloads 364
1109 Food Waste Management in the Restaurant Industry

Authors: Vijayakumar Karunamoothei, Stephen Wylie, Andy Shaw, Al Shamma'A Ahmed

Abstract:

The main aim of this research is to investigate, analyse and provide solutions for the reduction of food waste in the restaurant industry. The amount of food waste that is sent to landfill by UK restaurants and food chains is considerably high, and also acts as an additional cost to the restaurants, as well as being a significant environmental issue. Food waste, for the most part, is disposed in landfill, but due to rising costs associated with waste disposal, it increases public concerns about the environmental issue. This makes conversion of food waste to energy an economic solution. The relevant properties, such as water content and calorific value, will vary considerably, depending on the particular type of food. This work, therefore, includes the collection and analysis of real data from restaurants on weekly basis. It will also investigate how the waste destined for landfill can be instead reused to produce fuels such as syngas or ethanol, or alternatively as fertilizer. The potential for syngas production will be tested using a microwave plasma reactor.

Keywords: fertilizer, microwave, plasma reactor, syngas

Procedia PDF Downloads 359
1108 Antibiotic Resistance and Tolerance to Biocides in Enterobacter

Authors: Rebiahi Sid Ahmed, Boutarfi Zakaria, Rahmoun Malika, Antonio Galvez

Abstract:

The objective of this study was to explore the possible correlation between resistance to antibiotics and tolerance to biocides in Gram-negative bacilli isolated from the University Hospital Center of Tlemcen. This study focused on 175 clinical isolates of Gram-negative bacilli, it is a question of exploring: their level and profile of resistance to antibiotics, their tolerance to biocides, as well as the identification of the genetic supports of this resistance. Enterobacter spp. was the most predominant bacterial genus, all isolates harbored at least one of the studied genes with significant resistance capacity. Our results show, in some cases, a possible positive correlation between the presence of biocide tolerance genes and those of antibiotic resistance; in fact, tolerance to biocides could be one of the co-selection factors for antibiotic resistance. The results of this study should encourage the good practice of hygiene measures as well as the rational use of antimicrobials in order to hinder the development and emergence of resistance in our hospital departments.Mots clés : Antibiotiques, Biocides, Enterobacter, Hôpital, Résistance,

Keywords: antibiotic, biocides, enterobacter, hospital, resistance

Procedia PDF Downloads 116
1107 Mechanical Properties of CNT Reinforced Composite Using Berkovich Nanoindentation Analysis

Authors: Khondaker Sakil Ahmed, Ang Kok Keng, Shah Md Muniruzzaman

Abstract:

Spherical and Berkovich indentation tests are carried out numerically using finite element method for uniformly dispersed Carbon Nanotube (CNT) in the polymer matrix in which perfectly bonded CNT/matrix interface is considered. The Large strain elasto-plastic analysis is performed to investigate the actual scenario of nanoindentation test. This study investigates how the addition of CNT in polymer matrix influences the mechanical properties like hardness, elastic modulus of the nanocomposite. Since the wall thickness to radius ratio (t/r) is significantly small for SWCNT there is a huge possibility of lateral buckling which is a function of the location of indentation tip as well as the mechanical properties of matrix. Separate finite element models are constructed to compare the result with Berkovich indentation. This study also investigates the buckling behavior of different nanotube in a different polymer matrix.

Keywords: carbon nanotube, elasto-plastic, finite element model, nano-indentation

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1106 A Collaborative Platform for Multilingual Ontology Development

Authors: Ahmed Tawfik, Fausto Giunchiglia, Vincenzo Maltese

Abstract:

Ontologies provide a common understanding of a specific domain of interest that can be communicated between people and used as background knowledge for automated reasoning in a wide range of applications. In this paper we address the design of multilingual ontologies following well-defined knowledge engineering methodologies with the support of novel collaborative development approaches. In particular, we present a collaborative platform which allows ontologies to be developed incrementally in multiple languages. This is made possible via an appropriate mapping between language independent concepts and one lexicalization per language (or a lexical gap in case such lexicalization does not exist). The collaborative platform has been designed to support the development of the Universal Knowledge Core, a multilingual ontology currently in English, Italian, Chinese, Mongolian, Hindi, and Bangladeshi. Its design follows a workflow-based development methodology that models resources as a set of collaborative objects and assigns customizable workflows to build and maintain each collaborative object in a community driven manner, with extensive support of modern web 2.0 social and collaborative features.

Keywords: knowledge diversity, knowledge representation, ontology, development

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1105 Damage Analysis in Open Hole Composite Specimens by Acoustic Emission: Experimental Investigation

Authors: Youcef Faci, Ahmed Mebtouche, Badredine Maalem

Abstract:

n the present work, an experimental study is carried out using acoustic emission and DIC techniques to analyze the damage of open hole woven composite carbon/epoxy under solicitations. Damage mechanisms were identified based on acoustic emission parameters such as amplitude, energy, and cumulative account. The findings of the AE measurement were successfully identified by digital image correlation (DIC) measurements. The evolution value of bolt angle inclination during tensile tests was studied and analyzed. Consequently, the relationship between the bolt inclination angles during tensile tests associated with failure modes of fastened joints of composite materials is determined. Moreover, there is an interaction between laminate pattern, laminate thickness, fastener size and type, surface strain concentrations, and out-of-plane displacement. Conclusions are supported by microscopic visualizations of the composite specimen.

Keywords: tensile test, damage, acoustic emission, digital image correlation

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1104 Faults in the Projects, Deviation in the Cost

Authors: S. Ahmed, P. Dlask, B. Hasan

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There are several ways to estimate the cost of the construction project: simple and detailed. The process of estimating cost is usually done during the design stage, which should take long-time and the designer must give attention to all details. This paper explain the causes of the deviations occurring in the cost of the construction project, and determines the reasons of these differences between contractual cost and final cost of the construction project, through the study of literature review related to this field, and benefiting from the experience of workers in the field of building (owners, contractors) through designing a questionnaire, and finding the most ten important reasons and explain the relation between the contractual cost and the final cost according to these reasons. The difference between those values will be showed through diagrams drawn using the statistical program. In addition to studying the effects of overrun costs on the advancing of the project, and identify the most five important effects. According to the results, we can propose the right direction for the final cost evaluation and propose some measures that would help to control and adjust the deviation in the costs.

Keywords: construction projects, building, cost, estimating costs, delay, overrun

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1103 Board of Directors Characteristics and Credit Union Financial Performance

Authors: Luisa Unda, Kamran Ahmed, Paul Mather

Abstract:

We examine the effect of board characteristics on the performance and asset quality of credit unions in Australia, using a large sample covering the period 2004-2012. Credit unions are unique in that they are customer-owned financial institutions and directors are democratically elected by members, which is distinctly different from other financial institutions, such as commercial banks. We find that board remuneration, board expertise, and attendance at board meetings have significantly positive impacts on credit union performance and asset quality, while board members who hold multiple directorships (busy directors), have a significant negative impact on credit union performance. Financial performance also improves with larger boards and long-tenured directors in credit unions. All of these relations hold after we control for alternative measures of performance, credit union characteristics and endogeneity problem.

Keywords: credit unions, corporate governance, board of directors, financial performance, Australia, asset quality

Procedia PDF Downloads 518
1102 Improvement of Antibacterial Activity for Ceftazidime by Partially Purified Tannase from Penicillium expansum

Authors: Sahira N. Muslim, Alaa N. Mohammed, Saba Saadoon Khazaal, Batool Kadham Salman, Israa M. S. AL-Kadmy, Sraa N. Muslim, Ahmed S. Dwaish, Sawsan Mohammed Kareem, Sarah N. Aziz, Ruaa A. Jasim

Abstract:

Tannase has wide applications in food, beverage, brewing, cosmetics and chemical industries and one of the major applications of tannase is the production of gallic acid. Gallic acid is used for manufacturing of trimethoprim. In the present study, a local fungal strain of Penicillium expansum A4 isolated from spoilt apple samples gave the highest production level of tannase. Tannase was partially purified with a recovery yield of 92.52% and 6.32 fold of purification by precipitation using ammonium sulfate at 50% saturation. Tannase led to increased antimicrobial activity of ceftazidime against Pseudomonas aeruginosa and S. aureus and had a synergism effect at low concentrations of ceftazidime, and thus, tannase may be a useful adjuvant agent for the treatment of many bacterial infections in combination with ceftazidime.

Keywords: ceftazidime, Penicillium expansum, tannase, antimicrobial activity

Procedia PDF Downloads 741
1101 Facial Pose Classification Using Hilbert Space Filling Curve and Multidimensional Scaling

Authors: Mekamı Hayet, Bounoua Nacer, Benabderrahmane Sidahmed, Taleb Ahmed

Abstract:

Pose estimation is an important task in computer vision. Though the majority of the existing solutions provide good accuracy results, they are often overly complex and computationally expensive. In this perspective, we propose the use of dimensionality reduction techniques to address the problem of facial pose estimation. Firstly, a face image is converted into one-dimensional time series using Hilbert space filling curve, then the approach converts these time series data to a symbolic representation. Furthermore, a distance matrix is calculated between symbolic series of an input learning dataset of images, to generate classifiers of frontal vs. profile face pose. The proposed method is evaluated with three public datasets. Experimental results have shown that our approach is able to achieve a correct classification rate exceeding 97% with K-NN algorithm.

Keywords: machine learning, pattern recognition, facial pose classification, time series

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1100 Cost-Effective Hybrid Cloud Framework for Higher Educational Institutes

Authors: Shah Muhammad Butt, Ahmed Masaud Ansair

Abstract:

Present financial crisis in Higher Educational Institutes (HEIs) is causing lots of problems such as considerable budget cuts, which makes it difficult to meet the ever growing IT based research and learning needs. Institutions are rapidly planning and promoting cloud based approaches for their academic and research needs. A cost-effective hybrid cloud framework for HEIs will provide educational services for campus or intercampus communication. Hybrid cloud framework comprises private and public cloud approaches. This paper will propose the framework based on the Open Source Cloud (OpenNebula for Virtualization, Eucalyptus for Infrastructure and Aneka for programming development environment) combined with CSPs services which are delivered to the end-user via the internet from public clouds such as Google, Microsoft, Zoho, and Salesforce.

Keywords: educational services, hybrid campus cloud, open source, higher educational institutes

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