371 research outputs found

    The application of combined momentum and blade element theory for aerodynamics performance analysis of rotating blades

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    In this thesis, a simulation package for the Six Degrees of Freedom (6DOF ) motion of an underwater vehicle is developed. Mathematical modeling of an underwater vehicle is done and the parameters needed to write such a simulation package are obtained from an existing underwater vehicle available in the literature. Basic equations of motion are developed to simulate the motion of the underwater vehicle and the parameters needed for the hydrodynamic modeling of the vehicle is obtained from the available literature. 6DOF simulation package prepared for the underwater vehicle was developed using the MATLAB environment. S-function hierarchy is developed using the same platform with C++ programming language. With the usage of Sfunctions the problems related to the speed of the platform have been eliminated. The use of S- function hierarchy brought out the opportunity of running the simulation package on other independent platforms and get results for the simulation. Keywords: Underwater Vehicle Simulation, Virtual Reality Modeling Language (VRML ), MATLAB S-function, Simulink, C++, 6DOF

    Design and Implementation of CI/CD over LoRaWAN : Continuous Integration and Deployment in LoRaWAN Edge Computing Applications

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    The recent rise of IoT devices in commercial and industrial spaces has created a demand for energy-efficient and reliable communication solutions. Communication solutions used on IoT devices vary depending on the applications. Wireless Low Power Wide Area Network (LPWAN) technologies have proven benefits, including long-range, low power, and low-cost communication alternatives for IoT devices. These benefits come at the cost of limitations, such as lower data rates. At the same time, the demand for faster, cheaper, and more reliable software deployment is becoming more critical than ever before. This thesis aims to find a way of having an automated process where software could be remotely deployed into LoRa nodes and investigate whether it is possible to implement a DevOps pipeline with both Continuous Integration (CI) and Continuous Deployment (CD) over LoRaWAN. For this thesis, an IoT LoRaWAN Edge computing application was chosen to determine how to design and implement a CI/CD pipeline to ensure a dependable and a continuous software deployment to the LoRaWAN nodes. Designing and implementing a Continuous Deployment pipeline for this IoT application was made possible with the integration of DevOps tools like GitHub and a TeamCity automation server. Additionally, a series of scripts have been designed and developed for this case, including automated tests, integration to cloud services, and file fragmentation and defragmentation tools. For software deployment and verification to the LoRaWAN network, a program was designed to communicate with the LoRaWAN network server over the WebSocket communication protocol. The implementation of DevOps in LoRaWAN applications is affected by the limitations of the LoRaWAN protocol. This thesis argues that these limitations can be eliminated using modular software and file fragmentation techniques. The implementation presented in this work can be extended for various time-critical use cases. The solution presented in this thesis also opens the door to combining LoRaWAN with other LPWAN technologies, like NB-IoT, that can be activated on demand

    Effect of Information Quality on Accounting Firms Performance in Libya

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    The relationship between information and decision-making is a complex. More recently, researchers have suggested a relationship between the quality of information and the quality of decision-making, which is important to enhance the firm performance. Thus this study has investigated the impact of information quality on accounting firm performance in Libya. To investigate the relationship of information quality and accounting firm performance researcher has collected 120 samples from different accounting firms in Tripoli in Libya. It has found that there are positive relationship between information quality and accounting firm performance in Libya

    Computation Enhancement using Reconfigurable Computing

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    In light of the industry’s constant need for better computer performance, this project aims to choose and evaluate an approach for facing this issue. The targeted category of computers is single board computers (e.g. Raspberry Pi). The approach utilized for enhancing performance is the use of reconfigurable computing as to execute computationally expensive calculations on a runtime custom-tailored hardware. The objective of this project is the test of the potential this approach has for increasing computers performance through comparing a software implementation of an algorithm with an FPGA assisted implementation of the same algorithm. The platforms chosen for this project are the Rapsberry Pi and the Parallella P1602 board with its Zynq SoC for the software implementation and the FPGA assisted implementation in that order. The chosen algorithm is Fourier Fast Transform due to its part in many DSP applications and its suitability for the project objective. While the software solution worked successfully resulting in an asymptotic cost of O(N log N); the reconfigurable computing solution couldn’t be completed due to time constraints and lack of experience of the student. Future work should complete the experiment and add a multicore implementation of the same algorithm to add yet another class to the comparison

    Contribution of local-level trade in non timber forest products to rural development in Rashad locality of Nuba Mountains, Sudan

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    The principal aim of the study was to investigate the extent and under which conditions does local-level trade in Adansonia digitata, Ziziphus spina-christi and Balanites aegyptiaca fruits contribute to rural development- poverty alleviation- in Rashad of Nuba Mountains, Sudan. Purposive sampling technique was applied to select the 221 household collectors and 62 household traders in 2008/2009. Quantitative and qualitative data were collected through several methods including interviews, household survey, market surveys, direct observations, and through literature review. Both quantitative and qualitative methods were used to analyze the production-to-consumption system (PCS) of the three products and to assess their contribution to household income and expenditure. The results indicate that the contribution to total household‟s income was 51%, 42% and 26% for A. digitata, Z. spina-christi and B. aegyptiaca fruits, respectively. The A. digitata fruits case study represents accumulative and subsistence livelihood strategies; while Z. spina-christi and B. aegyptiaca fruits case studies represent a subsistence livelihood strategy for the households. The results also show that the financial returns from local-level trade in the selected NTFPs were negatively affected by different factors related to products markets, base resource, participants‟ attributes, and the political environment under which the products are traded. The study concluded that any assumption regarding the potential of the NTFPs case studies to affect rural development positively depends on the role of the product in financial capital creation and the related accumulative strategy. Thus, attention paid to not assume that all NTFPs have a potential for rural development- push people out of poverty. To promote the local-level trade in the studied NTFPs and influence future direction of their financial returns toward accumulative strategy, interventions and supports (e.g. access to microfinance, capacity building and organization of the actors, market information and resource management) are important.Das Hauptziel der Studie bestand darin zu untersuchen, in welchem Maße und unter welchen Bedingungen der Handel mit FrĂŒchten von Adansonia digitata, Ziziphus spina-christi und Balanites aegyptiaca zur ArmutsbekĂ€mpfung in Rashad im Gebirge Nuba Mountains, Sudan beitrĂ€gt. Das zielgerichtete Probenahmeverfahren wurde eingesetzt, um 221 Sammler und 62 HĂ€ndler von Haushalten im Zeitraum 2008/2009 auszuwĂ€hlen. Quantitative und qualitative Daten wurden durch mehrere Methoden erhoben, die Interviews, Haushaltserhebungen, direkte Beobachtungen sowie Literaturanalysen umfassen. Sowohl quantitative als auch qualitative Methoden kamen zum Einsatz, um das System von der Produktion zur Konsumption der drei Produkte zu analysieren und deren Beitrag zu den Einnahmen und Ausgaben der Haushalte zu beurteilen. Die Ergebnisse zeigen, dass der Beitrag zum Haushaltsgesamteinkommen 51%, 42% bzw. 26% fĂŒr A. digitata, Z. spina-christi bzw. B. aegyptiaca FrĂŒchte betrug. Die A. digitata FrĂŒchte-Fallstudie zeigt akkumulations- und eigenbedarfsorientierte Lebensunterhalts- und Erwerbsstrategien; wĂ€hrend die Fallstudien zu den FrĂŒchten von Z. spina-christi und B. aegyptiaca eine Eigenbedarfs-Lebensunterhaltsstrategie fĂŒr die Haushalte darstellen. Die Ergebnisse zeigen auch, dass die finanzielle Rendite vom Handel auf lokaler Ebene mit ausgewĂ€hlten NTFP„s (Nichtholzprodukten) durch verschiedene Faktoren negativ beeinflusst wurde, die in Beziehung stehen mit den MĂ€rkten fĂŒr die Erzeugnisse, mit der Ressource Baum, den Einstellungen der Teilnehmer und dem politischen Umfeld, in welchem die Produkte gehandelt wurden. Die Untersuchung legt den Schluss nahe, dass jede Annahme bezĂŒglich des Potentials von NTFP-Fallstudien, die lĂ€ndliche Entwicklung positiv zu beeinflussen, von der Rolle des Produkts bei der Bildung von Finanzkapital und der damit in Beziehung stehenden akkumulativen Strategie abhĂ€ngig ist. Somit wird die Aufmerksamkeit darauf gelenkt, dass nicht angenommen werden kann, dass alle NTFP„s ein Potenzial fĂŒr die lĂ€ndliche Entwicklung haben, und somit die Menschen aus der Armut herausfĂŒhren. Den Handel der untersuchten NTFP‟s auf lokaler Ebene zu fördern, und die kĂŒnftige Richtung des finanziellen Gewinns hinsichtlich akkumulativer Strategie, Interventionen und Hilfeleistungen (z.B. Zugang zu Mikrofinanzen, KapazitĂ€tsaufbau und Organisation von Akteuren, Marktinformationen und Ressourcenmanagement) zu beeinflussen, ist bedeutsam

    Exploring the English Language Teachers’ Attitudes Towards the Use of Pedagogical Dictionaries in their Classes (Sudanese Perspective)

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    The dictionary should always be present in language education. It is the tool with which EFL teachers can effectively perform teaching tasks in their classes. Good teachers should take on the habit of consulting their dictionaries to assimilate the lexical, syntactical, phonological, morphological, etymological and more other features of one word or expression that a good dictionary can provide. This paper is investigating the attitudes of English language teachers in the use of this important teaching aid. It is an additional viewpoint from EL teachers in four Sudanese State Universities on the use of dictionary in their classes. The findings of this research might be of significance to other researchers, teachers, language learners and textbook designers; and the results may be applicable in many similar EFL environments round the globe.

    Endobronchial Lipoma: A Case Report

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    Endobronchial lipoma is a benign tumor of the large bronchi occurring in middle-aged men. The symptoms are those of obstructive pneumonitis mimicking bronchogenic carcinoma, and the result of delayed therapy may be bronchiectasis. Treatment includes local resection through a bronchoscope or a bronchotomy incision, or removal, if necessary, of the obstructed lobe or lung at thoracotomy. Smoking may be important in the pathogenesis of this tumor. Case:A 37 years old man presented with symptoms of asthma. X-ray showed unilateral inflation of the left lung. Flexible bronchoscope showed well circumscribed rounded mass in left main bronchus .CT scan raises the possibility of a benign intrabronchial mass. Surgical excision of the mass and subsequent histological examination confirmed the diagnosis of endobronchial lipoma. Discussion: Bronchoscopic resection should be considered as the first choice of treatment for endobronchial lipoma; however, surgical therapy is indicated for patients who show the possibility of a complicated malignant tumor, who have destructive peripheral lung disease, who have extrabronchial growth, or who may have technical difficulties during the bronchoscopic procedur

    Significant Association of Streptococcus bovis with Malignant Gastrointestinal Diseases

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    Streptococcus bovis is a Gram-positive bacterium causing serious human infections, including endocarditis and bacteremia, and is usually associated with underlying disease. The aims of the current study were to compare prevalence of the bacterium associated with malignant and nonmalignant gastrointestinal diseases and to determine the susceptibility of the isolated strains to different antimicrobial agents. The result showed that the prevalence of S. bovis in stool specimens from patients with malignant or with nonmalignant gastrointestinal diseases was statistically significant. This result may support the idea that there is correlation between S. bovis and the malignant gastrointestinal diseases

    Multilayer graphene modified metal film electrodes for the determination of trace metals by anodic stripping voltammetry

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    Magister Scientiae - MScIn this study multilayer graphene nanosheets was synthesize by oxidizing graphite to graphene oxide using H2SO4 and KMnO4 followed by reduction of graphene oxide to graphene using NaBH4. The graphene nanosheets were characterized by Fourier Transform Infrared (FTIR) and Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). HRTEM images showed that the multilayer graphene were obtained. The graphene was immobilized directly onto a glassy carbon electrode using the drop coating technique followed by the in situ deposition of mercury, bismuth or antimony thin films to afford graphene modified glassy carbon metal film electrodes (Gr-GC-MEs). The experimental parameters (deposition potential, deposition time, rotation speed, frequency and amplitude) were optimized, and the applicability of the modified electrode was investigated towards the individual and simultaneous determination of Zn2+, Cd2+ and Pb2+ at the low concentration levels (ÎŒg L-1) in 0.1 M acetate buffer (pH 4.6) using square wave anodic stripping voltammetry (SWASV). The detection limits values for the Gr-GC-HgE was 0.08, 0.05 and 0.14 ÎŒg L-1 for Zn2+, Cd2+ and Pb2+, respectively. The Gr-GC-BiE the detection limits for was 0.12, 0.22 and 0.28 ÎŒg L-1 for Zn2+, Cd2+ and Pb2+ while the detection limits for the Gr-GC-SbE was 0.1, 0.3 and 0.3 ÎŒg L-1 for Zn2+, Cd2+ and Pb2+, respectively. A Gr-GCE prepared without any binding agents or metal film had detection limits for Zn2+, Cd2+ and Pb2+ of 3.9, 0.8 and 0.2 ÎŒg L-1 for Zn2+, Cd2+ and Pb2+. Real sample analysis of which was laboratory tap water was performed using the Gr-GCMEs. Only Gr-GC-HgE was sensitive enough to detect metal ions in the tap water samples at the 3ppb level whereas, the GC-BiE and GC-SbE detected the metal ions at the 10 ÎŒg L-1 to 30 ÎŒg L-1 level
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