Engineering Commons^™

Explicit Solution Of The Large Amplitude Transverse Vibrations Of A Flexible String Under Constant Tension, Ali Nikkar, Reza Taghipour, Tohid Akhlaghi

Ali Nikkar

This paper presents the analytical simulation of string with large amplitudes using the Variational Iteration Method (VIM) and Hamiltonian Approach (HA). In order to verify the precision of the presented methods, current results were compared with He’s Variational Approach and Runge-Kutta 4th order. It has been found that these methods are well suited for a range of parameters and the approximate frequencies and periodic solutions show a good agreement with other techniques. The results show that both methods can be easily extended to other nonlinear oscillations and it can be predicted that both methods can be found widely applicable ...

Infrared Transmitting Glasses With High Glass Transition Temperatures, Steve W. Martin

Iowa State University Patents

A chalcogenide glass capable of infrared transmission which is either sulfur, selenium or tellurium based and consists of compositions of the formula MX+M.sub.2 'X.sub.3 +SiX.sub.2, wherein M is one of the metals calcium, strontium, barium, zinc and lead, and M' is either aluminum or gallium and X is either sulfur, selenium or tellurium. Aluminum or gallium chalcogenide acts to increase the covalent bonding network structure of the glass with the result being that excellent high temperature 8-14 micron IR transmitting glasses with transition temperatures above 500C are prepared.

Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson

Mechanical & Materials Engineering Faculty Publications

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further ...

Study Of Nonlinear Vibration Of Euler-Bernoulli Beams By Using Analytical Approximate Techniques, Saman Bagheri, Ali Nikkar

Ali Nikkar

In this paper, nonlinear responses of a clamped-clamped buckled beam are investigated. Two efficient and easy mathematical techniques called He’s Variational Approach and Laplace Iteration Method are used to solve the governing differential equation of motion. To assess the accuracy of solutions, we compare the results with the Runge-Kutta 4th order. The results show that both methods can be easily extended to other nonlinear oscillations and it can be predicted that both methods can be found widely applicable in engineering and physics.

Fault Locating In Large Distribution Systems By Empirical Mode Decomposition And Core Vector Regression, Benyamin Khorramdel Mr., Hesamoddin Marzooghi Mr., Haidar Samet Dr., Meisam Pourahmadi-Nakhli Mr., Mahdi Raoofat Dr.

Hesamoddin Marzooghi

This paper proposes an intelligent fault locating method using a new signal analysis technique called Empirical Mode Decomposition (EMD) and Core Vector Regression (CVR) for large distribution systems. The conventional fault locators are based on the measurement of post-fault line impedance suffering from the factors such as path fault impedance, system configuration and line loading, so that they have low accuracy. On the other hand, because of the vast range of resistances, the negative impact of damping factors affects the performance of travelling wave-based fault locators in large distribution systems. To overcome these problems, this paper uses a minimum measuring ...

The Astral Box, Patrick C. Davis, Marshall J. Underwood, Zack R. Hicks, Jahan Z. Hussaini

University of Tennessee Honors Thesis Projects

No abstract provided.

Object Tracking By Pan Tilt System, Lily Hoang

University of Tennessee Honors Thesis Projects

No abstract provided.

Machine Learning Analysis Of Peripheral Physiology For Emotion Detection, Sarah M. Brown

Electrical and Computer Engineering Master's Theses

Peripheral physiological signals have shown promise as a measure of a person's emotional state. There are many applications where a more quantitative evaluation of an individual's mental state would be beneficial. For example, in PTSD or depression diagnosis, a quantitative measure to assist and compliment the qualitative assessments conducted by clinicians could reduce the time involved in treatment planning. A better understanding of the underlying mechanism is necessary for building systems that use these signals to assist in critical decision making.

Previous work in emotion research has relied upon averaging in time and then applying standard significance tests ...

Active Sensing For Dynamic, Non-Holonomic, Robust Visual Servoing, Avik De, Karl S. Bayer, Daniel E. Koditschek

Departmental Papers (ESE)

We consider the problem of visually servoing a legged vehicle with unicycle-like nonholonomic constraints subject to second-order fore-aft dynamics in its horizontal plane. We target applications to rugged environments characterized by complex terrain likely to perturb significantly the robot’s nominal dynamics. At the same time, it is crucial that the camera avoid “obstacle” poses where absolute localization would be compromised by even partial loss of landmark visibility. Hence, we seek a controller whose robustness against disturbances and obstacle avoidance capabilities can be assured by a strict global Lyapunov function. Since the nonholonomic constraints preclude smooth point stabilizability we introduce ...

Ptsa Doped Conducting Graphene/Polyaniline Nanocomposite Fibers: Thermoelectric Behavior And Electrode Analysis, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. I. Amal, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Highly conducting graphene/polyaniline (GN@Pani) nanocomposite was prepared by the in-situ oxidative polymerization of aniline in the presence of GN and the surfactant, cetyltrimethylammonium bromide (CTAB). The micellar structure of CTAB assisted both, the formation of GN@Pani tubules and the dispersion of GN. Sheet-like GN was distributed uniformly in the Pani matrix, leading to high electrical conductivity because of the π-π interactions between Pani and GN. Studies of the thermoelectrical behavior using isothermal and cyclic aging techniques showed that GN@Pani possessed a high combination of electrical conductivity and thermal stability, even beyond 150°C. GN@Pani was ...

Flow Accelerated Corrosion In Single And Dual S-Shape Bends Under Single And Two Phase Annular Flow Conditions, Hazem Mohamed Mohamed Ahmed Mazhar

Open Access Dissertations and Theses

Flow Accelerated Corrosion (FAC) is defined as a flow enhanced mass transfer phenomenon that results in pipe wall thinning of the piping system and results in abrupt failure in some cases. FAC is controlled by the transport of corrosion species from the wall to the bulk fluid and is determined by the local distribution of the mass transfer coefficient. The overall objective of this research is to investigate the mass transfer in pipe bends arranged in single and dual S- shape configurations under single and annular two phase flow conditions. A novel wall dissolving mass transfer technique was developed to ...

Surface Analysis Of Materials For Direct Wafer Bonding, Arif Ul Alam

Open Access Dissertations and Theses

Surface preparation and its exposure to different processing conditions is a key step in heterogeneous integration of electronics, photonics, fluidics and/or mechanical components for More-than-Moore applications. Therefore, it is critical to understand how various processing and environmental conditions affect the surface properties of bonding substrates. In this thesis, the effects of oxygen reactive-ion etching (O₂ RIE) plasma followed by storage in ambient and 98% relative humidity on some key surface properties such as roughness, water contact angle, hardness, and the elemental and compositional states of three materials – silicon (Si), silicon dioxide (SiO₂) and glass – are investigated to ...

Integer Programming-Based Approaches For Sustainable Community Applications, Wendy Huang

Open Access Dissertations and Theses

Sustainability is an important consideration in municipalities, and decision-makers are often faced with making trade-offs in decisions on cost, location selection, and allocation. These decisions are often riddled with complexities and uncertainties, and a heuristic approach can become costly and inefficient. Integer programming is a branch of mathematical programming that can be applied to problems such as these and can be a helpful tool in the decision making process.

This thesis presents three papers that develop and apply integer programming-based methodologies and their applications to problems faced by many communities: urban noise, school location-allocation and municipal solid waste collection.

An ...

Purification And Synthesis Of Pegylated Protein, Xiaojiao Shang

Open Access Dissertations and Theses

PEGylation, referring to the covalent attachment of poly(ethylene glycol) or PEG to protein, has become the most established technology for improving pharmacokinetic behavior of native proteins, especially the prolongation of circulation half-life in vivo. This thesis focuses on the synthesis and purification of PEGylated proteins.

The conventional way to synthesize PEGylated proteins is in liquid phase batch reaction, which usually causes the formation of significant amount and high diversity of by-products (i.e. di-, tri-, and/or higher-PEGylated forms of a protein). Many chemical and physical ways have been explored to increase the specificity of mono-PEGylated protein. Chemical ways ...

Growth, Characterization And Simulation Of Inas Quantum Wires On Vicinal Substrates, Andrew Scullion

Open Access Dissertations and Theses

The heteroepitaxial growth of InAs self-assembled quantum wires on vicinal substrates is investigated. InGaAlAs lattice-matched to InP was first deposited onto an InP(001) substrate with and without a 0.9 degree off-cut toward the (110) direction, followed by the deposition of a strained layer of InAs. Dense InAs quantum wires were successfully grown on both nominally flat and vicinal substrates in order to observe the effect of the presence of atomic steps. The off-cut angle was chosen based on the wire spacing on a flat substrate to serve as a template for their nucleation and improve their size distribution ...

Simulating Chemical Reactions Of Glass Powder In Cement Using Silica, Calcium Hydroxide And Sodium Hydroxide, Sarah Young

Open Access Dissertations and Theses

The use of supplementary cementitious materials (SCM) decreases the environmental impact of the cement industry. SCMs are commercial by-products that possess pozzolanic properties. Recycled glass powder, classified as a SCM, when added as a cement replacement reacts with the available lime in the cement to form calcium silicate hydrate (C-S-H) products. In contrast with other SCMs, glass is siliceous and thus the reaction can also cause alkali silica reaction (ASR) which causes expansion and cracking. This study was completed in order to characterize the chemical reactions and their rate using a simplified system that mimics glass particles in hardened cement ...

Six Degree-Of-Freedom, Musculotendon Joint Stiffness: Examples With The Knee, Joshua G. A. Cashaback

Open Access Dissertations and Theses

Increased muscle stiffness helps prevent excessive movement that can lead to ligament and soft-tissue damage. There is empirical evidence suggesting that muscles are important in preventing injuries caused by excessive translational movements. Very little is known, however, on how our muscles provide translational stiffness. This thesis uses complementary theoretical (Chapters 2 and 3) and experimental (Chapter 4) techniques to address how muscles provide translational joint stiffness.

In Chapters 2 and 3, we used an elastic energy approach to successfully derive equations that quantify muscular contributions to joint stiffness. From the equations, we were able to determine how the geometric orientation ...

The Wet Adhesion Of Polyvinylamine To Cellulose, John-Louis Diflavio

Open Access Dissertations and Theses

A systematic investigation of Polyvinylamine (PVAm) as a strength-enhancing polymer for wet paper was undertaken through the development of a new test method that simulates the influence of polymers on fibre-fibre bonding in paper. Pairs of wet regenerated cellulose membranes were laminated using the paper strength-enhancing polymer as the lamination adhesive. The resulting laminates served as a physical model for fibre-fibre bonds in paper and the wet laminate strength was determined by ninety degree peeling experiments. Key experimental parameters and sources of error were identified.

The mechanism of PVAm paper wet strength enhancement was explored by the wet cellulose delamination ...

An Investigation Into The Role Of Energy And Symmetry At Epitaxial Interfaces, Gabriel A. Devenyi

Open Access Dissertations and Theses

Epitaxy is a key technological process for the production of thin films and nanostructures for electronic and optoelectronic devices. The epitaxial process has been traditionally studied through the lens of lattice-matched and chemically similar material systems, specifically the III-V quaternary material systems. This work investigates the role energy and symmetry play at epitaxial interfaces for cases far different than those of typical epitaxy. In the realm of energy, the impact of chemically dissimilar epitaxial interfaces was investigated, specifically between semiconductors and oxides, noble metals and oxides, and polar-on-nonpolar epitaxy. For symmetry at epitaxial interfaces, the role of symmetry breaking, through ...

Energy Provisioning In Stand-Alone And Grid-Connected Solar Powered Networks, Mohammad Sheikh Zefreh

Open Access Dissertations and Theses

Solar energy is a clean and abundant renewable energy source which is currently used in many types of photovoltaic (PV) designs. In practical PV systems, solar panels are used to harvest solar energy and convert it into a usable form of electricity. Due to the intermittent nature of solar energy input however, battery storage, in combination with solar panels, must be used to provide an uninterrupted source of power.

The process of assigning solar panel and battery configurations for a PV system is referred to as energy resource provisioning. Unfortunately, energy provisioning costs are still relatively high, and this is ...

Synthetic Jet Micropump, Sherif Abdou

Open Access Dissertations and Theses

The production of a novel micropump based on the synthetic jet principle is investigated both numerically and experimentally. The proposed micropump consists of a synthetic jet actuator driven by a vibrating diaphragm issuing into an inverted T- shaped channel structure forming the inlet/outlet channels of the pump.

The software package Ansys is used to perform numerical investigations of the operation of the proposed micropump. Simulations were performed to study the effect of changing the inlet/outlet channel dimensions as well as the operating frequency, amplitude and duty cycle of the excitation signal. Inlet/outlet channel widths ranging from 200 ...

Asymmetrical I-V Curves From A Symmetrical Devices Structure Of Organic Photovoltaics, Shangzhi Chen

Open Access Dissertations and Theses

The energy diagram for organic photovoltaics (OPV), involving the bulk heterojunction (BHJ), on which the device analysis is usually based, has long been a subject of debate. The widely used Metal-insulator-Metal model and P-type Schottky Junction model, both of which are based on inappropriate assumptions, could be incorrect to explain the working principle of BHJ OPV.

To further explore the controversy, we start the investigation from the opposite direction, to the usually asymmetrical OPV, involving electron and hole passages, by introducing a pair of symmetric electrodes to a BHJ, to form a completely symmetrical device structure, which, in theory, would ...

Analyzing The Effects Of Ionic Strength, Particle Size And Particle Characteristics On The Transport Mechanisms Of Colloids In Single, Saturated Dolomite Fractures., Graham Seggewiss

Open Access Dissertations and Theses

A series of experiments were carried out to gain a better understanding of the mechanisms governing the transport of biological and non-biological particles through single, saturated dolomite fractures at the laboratory scale. Fracture apertures and general roughness were characterized using hydraulic and conservative solute tracer experiments.

The effects of particle size, surface characteristics and ionic strength of carrying solution were all evaluated. Particulate material studied included MS2, E. coli and two sizes of carboxylated microspheres. To elucidate the effect of ionic strength on particulate transport, the ionic strength of the carrying solution was altered during each experiment. All particulate experiments ...

External-Rotor 6/10 Switched Reluctance Motor For An Electric Bicycle, Jianing Lin

Open Access Dissertations and Theses

As a cost-effective, healthy, and environmentally friendly personal mode of transportation, electric bicycles (E-bikes) are gaining an increasing market share from conventional bicycles and automobiles. Considering the legal rules in Ontario, Canada, a 500W motor makes the E-bike more attractive for travelling use. At the same time, the simple structure, high torque and power density, as well as the low cost of the switched reluctance machine (SRM) makes it a strong candidate for E-bikes.

In this thesis, a 3-phase, external-rotor SRM with 6 stator poles and 10 rotor poles is designed for E-bike. The design of an external rotor arrangement ...

Heat-Affected Zone Softening Kinetics In Dual-Phase And Martensitic Steels, Elliot Biro

Open Access Dissertations and Theses

Advanced high strength steels, such as dual-phase and martensitic steels, are increasingly being used by automakers to decrease the thickness of steel sheet used in parts without sacrificing part strength. When welded, the martensite within the dual-phase and martensitic steel microstructures tempers, reducing the heat-affected zone (HAZ) hardness compared to the base material, locally reducing strength. This process is known as HAZ softening. HAZ softening has been well studied; however, the kinetics of this process has not been quantified and the processes responsible for HAZ softening have not been examined. This thesis investigated both of these topics.

HAZ softening was ...

Study Of Passive Optical Network (Pon) System And Devices, Qingyi Guo

Open Access Dissertations and Theses

The fiber-to-the-x (FTTX) has been widely investigated as a leading access technology to meet the ever growing demand for bandwidth in the last mile. The passive optical network (PON) provides a cost-effective and durable solution. In this thesis, we investigate different aspects of the PON, in the search for cost-effective and high-performance designs of link system and devices.

In Chapter 2, we propose a novel upstream link scheme for optical orthogonal frequency division multiplexing (OOFDM)-PON. The colorless laser diodes are used at the optical network units (ONUs), and the overlapped channel spectrum of orthogonal subcarrier multiplexing provides high spectral ...

Experiential Learning Through Simulation And Prototyping In First Year Engineering Design, Jon-Michael J. Booth

Open Access Dissertations and Theses

The act of engineering is synonymous with design. It is a skill that is inherently understood by experienced engineers, but also one of the most difficult topics to teach. For many years, Engineering Design and Graphics has been a required first year course for all engineering students at McMaster University. The course has taught hand-sketching, 3D solid modeling, system simulation, 3D rapid prototyping, and culminated in a design project in gear train design that requires a combination of the core course topics. Students chose their own three-member teams, and lab sections were randomly assigned one of three modalities for completion ...

Integration Of Time-Resolved Fluorescence And Diffuse Reflectance Spectroscopy For Intraoperative Detection Of Brain Tumour Margin, Zhaojun Nie

Open Access Dissertations and Theses

The annual incidence rate of tumours in the brain and central nervous system (CNS) was 19.89 per 100,000 persons between 2004 and 2008 in the United States. Surgery is a common treatment option for brain and CNS tumours. Typically, biopsy followed by histological analysis is used to confirm tumour types and margin during neurosurgery as an intraoperative diagnostic tool. However, this biopsy method is invasive, sampling number limited and not in real-time. To overcome these problems, many minimally invasive optical techniques, called optical biopsies, have been developed towards intraoperative diagnosis.

The research work carried out in this dissertation ...

Model-Iq: Uncertainty Propagation From Sensing To Modeling And Control In Buildings., Madhur Behl, Truong Nghiem, Rahul Mangharam

Real-Time and Embedded Systems Lab (mLAB)

A fundamental problem in the design of closed-loop Cyber-Physical Systems (CPS) is in accurately capturing the dynamics of the underlying physical system. To provide optimal control for such closed-loop systems, model-based controls require accurate physical plant models. It is hard to analytically establish (a) how data quality from sensors affects model accuracy, and consequently, (b) the effect of model accuracy on the operational cost of model-based controllers. We present the Model-IQ toolbox which, given a plant model and real input data, automatically evaluates the effect of this uncertainty propagation from sensor data to model accuracy to controller performance. We apply ...

Effects Of Physical Disturbances On Biosand Filters Used For Point-Of-Use Water Treatment, Naomi C. Mahaffy

Open Access Dissertations and Theses

Over 750 million people, 80% of whom live in rural communities, lack access to improved water sources. Even where an improved water source is easily accessible, recontamination and/or inadequate infrastructure may make it unsafe for human consumption. A lack of safe water leads to elevated rates of waterborne diseases and can exacerbate cycles of poverty by forcing individuals to miss school and work and to travel greater distances to secure better-quality water. Households in rural and remote communities may thus choose to use point-of-use treatment as a means of gaining greater control over their water quality and the health ...