Engineering Commons^™

A Traffic Metering And Marking Technique For Fair Bandwidth Allocation In High Speed Networks, Mary Looney

Theses

The deployment of Quality of Service (QoS) in high speed networks is vital to successful application delivery, especially those that are data-intensive. Continuous efforts have been made to develop infrastructures for enhancing QoS capabilities to manage available bandwidth through the use of traffic conditioners. However, research shows that these techniques distribute bandwidth in an unfair manner. This thesis addresses the failings of traffic conditioning techniques for bandwidth QoS provisioning. Traffic conditioners are comprised of two components, a traffic meter that is responsible for measuring transient characteristics of a traffic stream through a rate estimation technique and a traffic marker that …

Bridgeless High Power Factor Buck-Converter Operating In Discontinuous Capacitor Voltage Mode, Nasrullah Mohammad Awni Khraim

Theses

High power factor AC-DC rectifiers have gained a lot of attention due to demanding international regulations. The international harmonics’ standards, i.e. IEC 61000-3-2 and EN 61000-3-2 require low harmonic content of the main line current, or in other words, high power factor. Also, new market initiatives such as the 80 PLUS initiative, require high efficiency of the power supply. These standards specify the AC line current harmonics’ limits depending on load and application.

In this research, a new converter, with high power factor and high efficiency, operating in discontinuous capacitor voltage mode (DCVM) – is investigated targeting personal computers (PC) …

Strengthening Of Reinforced Concrete Beams Pre-Damaged In Shear, Yousef Mohammed Bachar Chekfeh

Theses

Repair and strengthening of existing reinforced concrete (RC) structures has increased drastically in recent years. Shear reinforcement in RC beams is typically of a small bar diameter, and hence any shear-damage would result in a severe safety hazard and a catastrophic mode of failure especially under extreme loading events. The present work was initiated to the effectiveness of different composite strengthening systems; namely externally bonded carbon fiber reinforced polymer (EB-CFRP), and near surface mounted glass fiber reinforced polymer (NSM-GFRP) to prolong the functional service life of RC beams pre-damaged in shear. It comprised experimental testing and analytical investigation.

The experimental …

Robust Transmission Of Images Based On Jpeg2000 Using Edge Information, Amjad Nazih Bou Matar

Theses

In multimedia communication and data storage, compression of data is essential to speed up the transmission rate, minimize the use of channel bandwidth, and minimize storage space. JPEG2000 is the new standard for image compression for transmission and storage. The drawback of Compression is that compressed data are more vulnerable to channel noise during transmission. Previous techniques for error concealment are classified into three groups depending on the Approach employed by the encoder and decoder: Forward Error Concealment, Error Concealment by Post Processing and Interactive Error Concealment. The objective of this thesis is to develop a Concealment methodology that has …

An Assessment Of Phosphorus Recovery From Dairy Wastewater, Éanna Kelleher

Theses

Phosphorus is an important nutrient for plant and animal life. It is one of the three essential nutrients required for plant growth; Nitrogen, Phosphorus and Potassium. It plays a vital role in the quality and structure of plants. In animals it is essential for the transfer of energy around the body and for the development of the skeleton. Phosphorus is mined from deposits of phosphate rock and is mainly used to produce fertiliser which is applied to agricultural land to improve plant growth. However, phosphorus is a finite resource and, similar to oil, is expected to peak during this century. …

Shear & Torsion Behaviour Of Hollow-Core Pre-Stressed Concrete Slabs, Cian Twomey

Theses

Research Aim The aim of this study is to carry out research on shear and torsion behaviour of hollow-core slabs.

Research Objectives The objectives of the research are: • carry out a review of research literature published to date • carry out physical laboratory testing • generate and calibrate Unite element models • expand finite element models to model shear and torsion behaviour of hollow- core slabs • carry out a comparison and discussion of the findings

Development Of A Low Cost Instrument For Tidal Flow Measurement, Thomas Daly

Theses

This project examines current technology for the production of energy from wave and tidal sources and the pros and cons of the different types of technology available. It also looks at the possibility of producing energy from tidal streams on a micro scale for local use. It identifies some of the barriers to this and attempts to solve one of those barriers by developing a low cost instrument which would be capable of assisting in the surveying of possible sites for micro tidal energy production in a cost effective way.

As part of this process an off the shelf marine …

The Structural Performance Of Timber Connections, Daniel Coleman

Theses

This thesis sets out to assess the behaviour of mechanically fastened timber-to-timber connections. The design aspects of timber connections are described in detail, with particular emphasis on nailed connections. The effects of inherent variations in timber properties on joint behaviour are also described.

The two types of connections considered were:

■ Corbel (cantilever);

■ Splice.

For each connection type, different nail configurations, nail diameters and shaft lengths were used. Testing undertaken was conducted to investigate the influence of a number of nail configurations on a connection’s initial stiffness. The test results, presented using moment- rotation curves are also used to …

Numerical Modelling Of The River Bandon, Stephen Finn

Theses

Numerical modelling involves the use of data from the physical environment and mathematical equations to achieve predictive solutions to many engineering problems including for river engineering. The field data is surveyed, sampled, recorded and tested before it is entered into the numerical modelling program for analysis. The numerical modelling program contains various mathematical equations that solve the data that has been entered. Numerical modelling is an important tool for predicting the consequences of future events. It can be used for predicting the damage of a 1 in 100 year flood event in a river system. Numerical modelling is used by …

Theoretical And Experimental Analysis Of Mems Ohmic Switch Design And Control For Reliability Improvement, Cuong Do

Theses

MEMS devices are micromechanical components fabricated using semiconductor fabrication technologies. With advanced functionalities and miniaturization, MEMS devices are being employed in a wide variety of applications, especially in mobile networks. The MEMS ohmic switch is one of the most promising MEMS devices and has the same principle of a mechanical moving switch to manipulate an electrical signal. Due to the existence of mechanical movement, and its compactness, reliability issues have been observed as the main barrier to commercialisation.

This thesis addresses the key issue of reliability in the rapidly expanding area of MEMS. In particular, MEMS ohmic switches are considered. …

A Service Provisioning Architecture For Next Generation Wireless Sensor Networks - The Wsn Cloud, Muhammad Sohaib Aslam

Theses

The relentless demand for pervasive computing in our everyday lives has led to and will continue to drive the roll out of large scale embedded systems in the form of Wireless Sensor Networks or WSNs in our environment. This in turn drives the need for reusable, flexible and manageable WSN infrastructures. To simplify system operation and maintenance as well as to reduce costs, WSNs must become an infrastructure that is capable of providing services to multiple end users concurrently rather than having to roll out individual infrastructures for specific purposes as is typical nowadays. This thesis presents the concept of …

Wireless Sensor Networks: Empowering Reliable, Realtime & Resource Efficient Communication For Cyber-Physical Applications, Jasvinder Singh

Theses

Since their inception, Wireless Sensor Networks (WSNs) have been successfully employed as low-rate data gathering networks in numerous monitoring applications. Recently, a new domain of WSNs applications, known as Cyber-Physical Systems (CPS) has started attracting significant attention world-wide. In these applications, monitoring only the state of the physical system (process or environment) is not sufficient, the system must respond to the sensed events/data within certain time constraints by performing actions upon the physical entity. It is expected that in approaching years, WSNs will be integrated in a myriad of CPS applications, for example high confidence medical systems, assisted living, traffic …

Strengthening Of Steel Beams Using Mechanically Anchored Carbon Fiber Reinforced Polymers Laminates, Mohammed Monir Makin Ajan Alhadid

Theses

على مدى العقدين المنصرمين من الزمن تم إستخدام الألياف البلاستيكية المسلحة بشكل فعال و عملي في تقوية وتدعيم المنشأت الهندسية المختلفة بما في ذلك العناصر الإنشائية الخرسانية والطابوقية والخشبية, وطوال هذه الفترة الزمنية جرت أبحاث مفصلة حول العالم لدراسة مدى فاعلية مثل هذه الألياف في تقوية العناصر المعدنية و ذلك عن طريق تثبيتها بواسطة مواد شديدة الإلتصاقو ولقد كشفت الدراسات المنشورة أن هذه الطريقة في التثبيت سواءً في العناصر الخرسانية أو العناصر المعدنية تؤدي الي الانهيار الفجائي للعناصر المدعمة عند قيم التحميل المرتفعة ما لم يتم اتخاذ احتياطات أخرى وخصوصاً عند أطراف هذه الألياف، وبالمقابل فإن هناك دراسات أخرى أجريت …

Development Of A Vibration-Powered Impact Recorder, William Contreras

Theses

Currently, the U.S. Army stores a great deal of equipment for long periods of time. Often, this equipment is subjected to damaging vibrations. Given this, the army wants to be able to monitor the vibrations that are undergone by this equipment. Here, a battery-powered monitoring device would be undesirable because its batteries would need to be replaced. To solve this problem, an energy harvesting, vibration monitoring device has been developed. The device, which is known as a vibration-powered impact recorder (VPIR for short), uses a piezoelectric transducer to power a microcontroller, which uses the power to count the number of …

Influence Of Rear Wheel Tire Type On Wheelchair Propulsion Biomechanics, Mathew Yarossi

Theses

The objective of this study was to determine how rear wheel tire type affects wheelchair propulsion mechanics. Four persons with paraplegia and four persons with tetraplegia propelled their own wheelchairs on a roller system at self-selected speed using five different pairs of tires. Upper limb and trunk kinematics, perceived exertion, stroke pattern and the temporal characteristics of propulsion were measured. When using pneumatic (air filled) tires, with lower rolling resistance, participants had lower push frequency (p < .05), higher self selected speed (p < .05), less perceived exertion, less shoulder internal rotation, and a longer push stroke than when using solid, high rolling resistance tires. As rolling resistance increased, participants experienced negative changes in propulsion characteristic that contradicted current clinical practice guidelines for upper limb preservation following spinal cord injury. In addition, kinematics with solid, high rolling resistance tires were similar to those described during uphill or over carpet propulsion. In order to avoid unnecessary strain on the upper limbs and unwanted changes in propulsion biomechanics, wheelchair users, clinicians, and researchers should consider the use of lower rolling resistance, pneumatic rear tires.

Orthogonal Space Time Coding For Im/Dd Optical Wireless Communication With Single Carrier Frequency Domain Equalization, Nan Wu

Theses

Recently the development of optical wireless communication has received growing attention because of its unlimited bandwidth and simple implementation as compared to radio frequency communication application for indoor wireless data transmission. The objective of this thesis is to improve the performance of intensity-modulated direct- detection (IM/DD) optical wireless communications with single carrier frequency domain equalization (SCFDE) by using Orthogonal Space Time Code (OSTC). More attention has been paid to three SCFDE schemes due to their outstanding performances in practical cases. It is demonstrated that OSTC can be modified to be suitable to optical systems and provide an excellent enhancement to …

Use Of Fluorescent Micropsheres To Measure Coronary Flow Reserve In Rat Animal Model, Riddhi Harsh Shah

Theses

Heart attacks result from reduced or blocked blood flow through major coronary arteries, resulting in permanent damage to heart muscle. Coronary blood flow (CBF) is thus important to measure in experimental animal models of heart disease. A standard method to measure CBF uses tracer microspheres (Ø = 15 µm) injected into the left ventricle that flow through coronary arteries but cannot pass through capillaries and so become trapped in heart muscle. Previously, radioactive or colored microspheres have quantified the number of tracers trapped in the muscle. Fluorescent microspheres offer a more recent and more sensitive measurement mode. However, fluorescent microspheres …

Elasto-Plastic Lateral Torsional Buckling Of Steel Beams With Perforated Web, Mohammad Iqbal Mohammad Hesham Martini

Theses

I-shaped steel members represent the basic structural element in the majority of steel structures. Perforated-web I-shaped steel sections have been used as structural members since the Second World War in an attempt to enhance the flexural behavior of traditional solid-webbed I-shaped steel sections without increasing the cost of the material. In general, two types of web perforations are commonly used in engineering practice; hexagonal and circular. Although, the main intent of the perforation process is to produce stiffer I-sections by increasing the web height and providing higher major-axis flexural capacity than solid-webbed members of the same weight, it also provides …

Dissolution Of Disintegrating Solid Dosage Forms In A Modified Dissolution Testing Apparatus 2, Shrutiben Rameshbhai Parekh

Theses

Dissolution tests are routinely carried out in the pharmaceutical industry to determine the dissolution rate of solid dosage forms. Dissolution testing serves as a surrogate for drug bioavailability through in vitro–in vivo correlation (IVIVR), and it additionally helps in guiding the development of new formulations and in assessing lot-to-lot consistency, thus ensuring product quality. The United States Pharmacopoeia (USP) Dissolution Testing Apparatus 2 is the device most commonly used for this purpose. Despite its widespread use, dissolution testing using this apparatus remains susceptible to significant error and test failures. There is documented evidence that this apparatus is sensitive to several …

The Effect Of Dynamic Standing On The Bone Mineral Density Of Non-Ambulatory Children: A Pilot Study, Megan Diane Damcott

Theses

In recent decades, research in osteoporosis has expanded to include the effects of prolonged immobilization on the load-bearing bones of non-ambulatory children. One current therapeutic intervention for this population is a passive standing program, in which the body is fully supported and continuous, stationary loading is applied to the bones, leading to the legs being primarily inactive. This research focused upon the effect of passive standing and a new therapeutic intervention of dynamic standing, a standing therapy in which the body is supported but vertical, reciprocal displacements which mimic the walking gait are applied to the feet, causing the muscles …

Dissolution Testing Of Prednisone And Salicylic Acid Calibrator Tablets At Different Tablet Locations, Anandhavalavan Arulmozhi

Theses

Dissolution testing is routinely carried out in the pharmaceutical industry to determine the rate of dissolution of solid dosage forms. This test is one of the several tests that pharmaceutical companies typically conduct on oral dosage formulations (e.g., tablets) to determine compliance. The USP Dissolution Testing Apparatus 2 is the most common of the apparatuses listed in the USP. However, it has been shown previously that the dissolution profile of a tablet undergoing dissolution in the USP Dissolution Apparatus 2 can be affected by the tablet location in the apparatus.

In this work, the dissolution rates of both non-disintegrating tablets …

Digital Image Forensics, Fei Long

Theses

Digital image forensics is a relatively new research field that aims to expose the origin and composition of, and the history of processing applied to digital images. Hence, the digital image forensics is expected to be of significant importance to our modern society in which the digital media are getting more and more popular. In this thesis, image tampering detection and classification of double JPEG compression are the two major subjects studied. Since any manipulation applied to digital images changes image statistics, identifying statistical artifacts becomes critically important in image forensics. In this thesis, a few typical forensic techniques have …

A Microfluidic Culture For Two Populations Of Dorsal Root Ganglia For Differential Staining, Ishnoor Sidhu

Theses

The goal of this study was to design and fabricate a microfluidic system that can be used to visibly distinguish the two populations of dorsal root ganglia (DRGs) by differential staining. Polydimethylsiloxane (PDMS) is the most widely used silicon-based organic polymer, and is particularly known for its wide spread use in microfluidics. Various methods have been employed to pump fluids in these channels for applications ranging from patterning of cells and biomolecules to control of local environment factors such as temperature, which requires external pumping or other applied forces. We demonstrated a pump-free device that exploits the surface energy stored …

Transdermal And Transbuccal Delivery Of Lidocaine And Nicotine : Combined Effects Of Iontophoresis And Chemical Enhancers, Ran Wei

Theses

This study focused on the effects of iontophoresis and chemical enhancers on drug release. The transport of Lidocaine HCl (LHCl) and Nicotine Hydrogen Tartrate (NHT) through the skin and mucosa was evaluated for potential clinical applications. These two potential delivery routes have the advantage of avoiding first-pass effect. Samples were pretreated with enhancer solutions for one hour before the experiments. Passive or 0.3 mA iontophoresis-assisted drug diffusion was conducted for 8 hours to monitor the cumulative amount of drug released. Graphical methods and mathematical optimization techniques were implemented to analyze the data. The effects of chemical enhancers on the delivery …

Investigation Of The Potential Catalytic Activities Of Several Metal Organic Framework (Mof) Materials, Guangyu Zhang

Theses

Metal-organic frameworks (MOFs) are promising porous materials due to their high porosities, large apparent surface areas, tunable pore properties and selective uptake of small molecules. Many researches have been focused on developing new MOF structures and exploring their use in gas storage and separation. Only few studies investigated the catalytic properties of MOFs. In this study, catalytic properties are explored over several MOFs including zeolitic imidazolate framework-8 (ZIF-8), Ni(FA) and Zn(FA). These MOFs are used as catalyst supports for iron or platinum nanoparticles. The catalysts are prepared using incipient wetness impregnation method and characterized with Brunauer-Emmett-Teller (BET), pulse chemisorption, X-ray …

Design And Evaluation Of An Adaptable Vector Coprocessor For Multicores, Timothy William Steele

Theses

Future applications for multi-core processor systems will require increased signal processing power along with increased resource utilization and decreased power consumption. Conservative power consumption will be of paramount importance primarily for battery-powered portable multi-core platforms (e.g., advanced cell phones, tablet computers, etc.). This thesis investigates the robustness, efficiency and effectiveness of vector coprocessor sharing policies in multi-core environments. Vector coprocessor sharing is based on an innovative design for a vector lane that forms the building block for the creation of larger vector coprocessors. This innovative lane design contains a floating-point multiply unit, a floating-point add/subtract unit, a miscellaneous function unit, …

Thermochemical Properties, Bond Energies And Internal Rotor Potentials In Methyl Ethyl Sulfide And Oxygenated Sulfur Hydrocarbons Intermediates For Modeling Its Combustion And Atmospheric Chemistry, Guanghui Song

Theses

Small (1 to 4 carbon) hydrocarbon sulfides and thiols are formed in the biosphere by microorganisms and subsequently emitted into the lithosphere, hydrosphere and atmosphere. In the atmosphere they are oxidized by photochemical and radical reactions to intermediate hydrocarbon and to sulfur oxides. The oxides of these sulfur compounds and the intermediates from the oxidation process are known to form aerosols that can counteract the global warming green house effect. Recent studies also suggest that some aerosols can also contribute to global warming. Sulfur oxides are also major contributors to acid rain as the results of the atmospheric chemistry oxidation …

Tilt Simulation : Virtual Reality Based Upper Extremity Stroke Rehabilitation, Harish Damodaran

Theses

The primary objective of this research is to design a recreational rehabilitation videogame that interactively encourages purposeful upper extremity gross motor movements. The simulation is also capable of continuous game modification to fit changing therapy goals, to match the needs of the players, and to provide continued motivation while capturing the interactive repetition. This thesis explains the design and features of this latest simulation - Tilt. Tilt uses physics to develop an engaging training experience and provides a realistic approach to virtual reality simulation including friction, elasticity and collisions between objects. It is designed to train upper extremity function as …

Energy Scavenging System For Indoor Wireless Sensor Network, David Andrew Crea

Theses

As wireless communication evolves wireless sensors have begun to be integrated into society more and more. As these sensors are used to a greater extent newer and better ways to keep them working optimally have begun to surface. One such method aims to further the sensors energy independence on humans. This technique is known as energy scavenging. The logic behind energy scavenging is to allow the device to have its own reliable source of energy that does not require upkeep, has a long life expectancy, and does not completely rely on an internal power source. The aim of this thesis …

Non-Invasive Interventions Top Reduce Low Back Dysfunction, Nadi Atalla

Theses

This study aims to quantitatively evaluate the low back condition so that low back dysfunction can be identified and classified when measurements show a variance from the normal. The evaluation is done by using the hysteresis concept. In this study, subjects received two different types of treatment: massaging using a mechanical massager for ten minutes and manual massaging by a professional physician. Using the Automated Anatomic Torsion Monitor (A-ATM), the low back of the subject was evaluated before and after treatment. The change in Hysteresis Loop Area (HLA) was -12.5% for mechanical massaging and -15.7% for manual massaging. The negative …