Engineering Commons^™

Landfill Gas As A Fuel For Ic Engine Operations, Guruprasath Narayanan

Masters Theses

An alternative fuel research facility was developed to study different alternative gaseous fuels like Landfill gases and Biogases and their mixtures with hydrogen as a fuel in a single cylinder spark ignition engine. Landfill gas was used as a fuel and the optimum process parameters such as compression ratio, spark timing and equivalence ratio were identified and reported.

Hydrogen enhanced combustion of landfill gas was studied and it was found that the addition of small amounts of hydrogen in the land fill gas has improved the combustion characteristics of the fuel and the performance of the spark ignition engine in …

The Land Is In Your Hands : A Practical Guide For Owners Of Small Rural Landholdings In Western Australia, Department Of Agriculture And Food, Wa

Bulletins 4000 -

This Bulletin discusses various aspects of managing a small farm or property in Western Australia, including soil and land care, vegetation and plant control on farm holdings, water resource management, biosecurity, plant, animal and insect pest control and livestock management.

Ink Jet Inks And Substrates - Novel Approaches For Their Physical And Optical Properties Characterization, Veronika Lovell

Dissertations

Undoubtedly, within the last couple of decades, the progress in non impact printing technologies has grown to an enormous level. In order to keep the development of this non impact printing method to grow even more, technicians, researchers and educators must continue in conducting investigation and provoking new ideas and questions that will lead to new outcomes and expansion of ink jet printing.

In this work, a broader area that comprises deep look into the ink jet ink and substrate performance, their physical properties and optical properties when printed is discussed in great details. Innovative techniques, novel materials and novel …

Robust Kanban Design For A Lean Supply Chain, Hardik Shah

Dissertations

This research concentrates on the inventory management decisions within an assembly-type supply chain. The need for this type of investigation is warranted by the fact that intense competition and heightening demand from customers have forced businesses to focus their attention on strengthening their supply chains. The problem is that in any supply chain, there are many factors involved that cause variations and instability within the system. Previous literature indicates that the manipulation of a Kanban system in today's uncertain environment generates unfavorable results. Consequently, the goal is to find a Kanbanmethodology that would produce robust and consistent results even when …

Human Error And Commercial Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using Hfacs, Scott Shappell, Cristy Detwiler, Kali Holcomb, Carla Hackworth, Albert Boquet, Douglas Wiegmann

Publications

The Human Factors Analysis and Classification System (HFACS) is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research has shown that HFACS can be reliably used to identify general trends in the human factors associated with military and general aviation accidents. The aim of this study was to extend previous examinations of aviation accidents to include specific aircrew, environmental, supervisory, and organizational factors associated with 14 CFR Part 121 (Air Carrier) and 14 CFR Part 135 (Commuter) accidents using HFACS. The majority of causal factors were attributed to the aircrew and the …

Development Of A Theoretical Framework Of Distributed Cognition Phenomena In Control Centers During Crisis Conditions, Christopher J. West

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research is to develop and partially validate a theoretical framework describing distributed cognition phenomena occurring in organizational control centers functioning in crisis environments. Using a systems approach, the work synthesizes existing constructs relating to distributed cognition then supplements this knowledge with review of crisis management literature. The goal of this effort is the development of a framework for understanding the impact of crisis conditions on such phenomena occurring within the specified setting. An exploratory case study approach was used to partially validate and refine the framework by gauging its ability to interpret the impact of crisis …

An Adaptive Algorithm To Identify Ambiguous Prostate Capsule Boundary Lines For Three-Dimensional Reconstruction And Quantitation, Rania Yousry Hussein

Electrical & Computer Engineering Theses & Dissertations

Currently there are few parameters that are used to compare the efficiency of different methods of cancerous prostate surgical removal. An accurate assessment of the percentage and depth of extra-capsular soft tissue removed with the prostate by the various surgical techniques can help surgeons determine the appropriateness of surgical approaches. Additionally, an objective assessment can allow a particular surgeon to compare individual performance against a standard. In order to facilitate 3D reconstruction and objective analysis and thus provide more accurate quantitation results when analyzing specimens, it is essential to automatically identify the capsule line that separates the prostate gland tissue …

Learning As A Nonlinear Line Of Attraction For Pattern Association, Classification And Recognition, Ming-Jung Seow

Electrical & Computer Engineering Theses & Dissertations

Development of a mathematical model for learning a nonlinear line of attraction is presented in this dissertation, in contrast to the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete location in state space. A nonlinear line of attraction is the encapsulation of attractive fixed points scattered in state space as an attractive nonlinear line, describing patterns with similar characteristics as a family of patterns.

It is usually of prime imperative to guarantee the convergence of the dynamics of the recurrent network for associative learning and recall. We propose to alter …

High Performance Queueing And Scheduling In Support Of Multicasting In Input-Queued Switches, Weiying Zhu

Electrical & Computer Engineering Theses & Dissertations

Due to its mild requirement on the bandwidth of switching fabric and internal memory, the input-queued architecture is a practical solution for today's very high-speed switches. One of the notoriously difficult problems in the design of input-queued switches with very high link rates is the high performance queueing and scheduling of multicast traffic. This dissertation focuses on proposing novel solutions for this problem. The design challenge stems from the nature of multicast traffic, i.e., a multicast packet typically has multiple destinations. On the one hand, this nature makes queueing and scheduling of multicast traffic much more difficult than that of …

Performance Analysis Of Recoverable Flight Control Systems Subject To Neutron-Induced Upsets Using Hybrid Dynamical Models, Hong Zhang

Electrical & Computer Engineering Theses & Dissertations

It has been observed that atmospheric neutrons can produce single-event upsets in digital flight control hardware. Potentially, they can reduce system performance and introduce a safety hazard. One experimental system-level approach investigated to help mitigate the effects of these upsets is NASA Langley's Recoverable Computer System. It employs rollback error recovery using dual-lock-step processors together with new fault tolerant architectures and communication subsystems.

In this dissertation, a class of stochastic hybrid dynamical models, which consists of a jump-linear system and a stochastic finite-state automaton, is used to describe the performance of a Boeing 737 aircraft system in closed-loop with a …

Micron-Level Actuator For Thermal-Fluid Control In Microchannels, Nurhak Erbas

Mechanical & Aerospace Engineering Theses & Dissertations

Effectiveness of an actuator is investigated for thermal-flow control in microchannels. First, simulations of a single actuator in a quiescent external medium are performed in order to study the parameters characterizing the synthetic jet flow from the actuator. For this purpose, a simplified, two-dimensional configuration is considered. The membrane motion is modeled in a realistic manner as a moving boundary in order to accurately compute the flow inside the actuator cavity. The geometric and actuation parameters of the actuator are investigated to define the effectiveness of the jet flow. The study is done initially at macro scales. Then, the flow …

The Ibm Rational Unified Process For Cots Package Delivery Roadmap, Cécile Péraire, Russell Pannone

Cécile Péraire

No abstract provided.

Forisome Based Biomimetic Smart Materials, Amy Shen, Benjamin Hamlington, Michael Knoblauch, Winfried Peters, William Pickard

Winfried S. Peters

Inventions On Ldap- A Study Based On Us Patents, Umakant Mishra

Umakant Mishra

Lightweight Directory Access Protocol (LDAP) is an IETF open standard to provide directory services in the network. LDAP is based on X.500 directory architecture, intended to provide directory services in Internet compatible environments. LDAP is used to provide directory services to applications ranging from e-mail systems to distributed system management tools. LDAP is becoming more and more popular with its wider usage in the Internet.

This report on LDAP is based on a study of 60 selected patents on LDAP from US patent database. The objective of this article is to present the distribution of patents according to different features …

Afci Quarterly Input – Unlv April 1 Through June 30, 2006, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects, activities and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.

The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For The Yucca Mountain Repository — Quarterly Technical Report No. 8, Dhanesh Chandra, Jaak J.K. Daemen

Publications (YM)

This report shows the work done for this period, in accordance to cooperative agreement of University of Nevada system for the Task 019 “Subsurface Corrosion Research on Rock Bolt System, Perforated SS Sheets and Steel Sets for the Yucca Mountain Repository”, the overall objective of which is to conduct corrosion research and predict the durability of rock-bolts and other underground metallic roof supports. We are performing oxidation tests using Thermogravimetric Analyzer (TGA), and Potentiodynamic tests to determine the corrosion rates of rock bolts, other support materials including bench mark materials.

In this quarter, we have performed:

Potentiodynamic tests were performed …

Shot Noise And Conductance In Metallic Carbon Nanotubes In The Presence Of Correlated Defects, Q. Zhang, H. Yang, C. Zhang, Z. Ma

Faculty of Engineering - Papers (Archive)

We investigate the effect of isolated scattering centers on the electronic transport in metallic carbon nanotubes. It is found that the impurity potential significantly alters the overlap of electronic wave functions and results in a rapid oscillation in the conductance and the shot noise. Furthermore, the conductance and the shot noise near the neutral Fermi energy depend periodically on the relative position of the scatterers and on the phase factor ϕ which is generated by the scattering. If two defects are in the same sublattice and Δd≫a_c, the conductance near the neutral Fermi energy is dropped to G …

A Comparative Study Of Athletic Apparel Made From Cotton/Flax, Cotton/Polyester, And Polyester/Flax Blends, Elizabeth Skomra

Master's Theses and Doctoral Dissertations

The desired attributes of sports apparel garments are to have durability characteristics, such as tearing and tensile strength, and comfort characteristics, such as wicking, vapor transmission, and air permeability. Currently, most sports apparel is made from a blend of polyester or other synthetic fibers. Through examining the uniqueness of natural fibers, such as cotton and flax, the advantages and benefits of using a higher percentage of natural fibers when manufacturing comfortable and functional high performance athletic wear can be obtained.

Results from this study, regarding durability, determined that for both tearing and breaking strength, traditional sports apparel made with polyester/cotton …

Electro-Oxidation Of Ethanol On Pt-Wo3/C Electrocatalyst, D. Y. Zhang, Z. F. Ma, G. X. Wang, Konstantin Konstantinov, X. X. Yuan, Hua-Kun Liu

Faculty of Engineering - Papers (Archive)

Ptx-WO3/C electrocatalysts were prepared by microwave colloid-reduction method. Transmission electron microscopy examination showed uniform dispersion of platinum with particle sizes less than 5 nm. Structures of the Ptx-WO3/C electrocatalysts were characterized by X-ray diffraction and energy dispersive spectroscopy, the electrochemical characteristics and electro-oxidation of electro-oxidation of ethanol on the Ptx-WO3/C electrocatalysts were also studied by cyclic voltammetry, linear sweep, and chronoamperometry. The results show that the Ptx-WO3/C electrocatalysts have higher catalytic activity to ethanol electrooxidation than the commercial Pt/C catalysts; perhaps caused by the “hydrogen spill-over effect.” The reaction mechanisms of the ethanol electro-oxidation on the Ptx-WO3/C were inferred according …

A Geologic Play Book For Trenton-Black River Appalachian Basin Exploration, Douglas G. Patchen, John Hickman, David C. Harris, James A. Drahovzal, Paul D. Lake, Langhorne B. Smith, Richard Nyahay, Rose Schulze, Ronald A. Riley, Mark T. Baranoski, Larry H. Wickstrom, Christopher D. Laughrey, Jaime Kostelnik, John A. Harper, Katharine Lee Avary, John Bocan, Michael Ed Hohn, Ronald Mcdowell

Appalachian Oil and Natural Gas Research Consortium

Appalachian basin architecture during Middle Ordovician time was dominated by a Black River ramp to the northwest flanked by the central Appalachian basin along its southeast margin, with the deeper Sevier basin still farther to the east and southeast. The ramp margin, which marked the western edge of the central Appalachian basin, was in the approximate location of the western edge of the Rome trough. Black River carbonate rocks were deposited on this broad, stable, shallow-water ramp as epeiric seas transgressed much of what is now the Appalachian region, while thick, shaley carbonates were being deposited within the trough-influenced foredeep …

Compact Autonomous Explosive-Driven Pulsed Power System Based On A Capacitive Energy Storage Charged By A High-Voltage Shock-Wave Ferromagnetic Generator, S. I. Shkuratov, E. F. Talantsev, Jason Baird, Larry L. Altgilbers, A. H. Stults

Mining Engineering Faculty Research & Creative Works

A new concept for constructing compact autonomous pulsed power systems is presented. This concept utilizes a high-voltage explosive-driven shock-wave ferromagnetic generator (FMG) as a charging source for capacitive energy storage. It has been experimentally demonstrated that miniature FMGs (22-25 cm³ in size and 84-95 g in mass) developed for these experiments can be successfully used to charge capacitor banks. The FMGs, containing Nd₂Fe₁₄B energy-carrying elements, provided pulsed powers of 35-45 kW in times ranging from 10 to 15 µs. A methodology was developed for digital simulation of the operation of the transverse FMG. Experimental results that were obtained are in …

Seal Assembly For Machinery Housing, Lyndon Scott Stephens, Kevin W. Kelly

Mechanical Engineering Faculty Patents

A seal assembly for a machinery housing includes a seal ring having a micro heat exchanger and a gland plate for securing the seal ring to the machinery housing. The gland plate includes a cooling fluid port in communication with the micro heat exchanger.

Critical Computational Aspects Of Near Infrared Circular Tomographic Imaging: Analysis Of Measurement Number, Mesh Resolution And Reconstruction Basis, Phaneendra K. Yalavarthy, Hamid Dehghani, Brian W. Pogue, Keit D. Paulsen

Dartmouth Scholarship

The image resolution and contrast in Near-Infrared (NIR) tomographic image reconstruction are affected by parameters such as the number of boundary measurements, the mesh resolution in the forward calculation and the reconstruction basis. Increasing the number of measurements tends to make the sensitivity of the domain more uniform reducing the hypersensitivity at the boundary. Using singular-value decomposition (SVD) and reconstructed images, it is shown that the numbers of 16 or 24 fibers are sufficient for imaging the 2D circular domain for the case of 1% noise in the data. The number of useful singular values increases as the logarithm of …

Comparison Matrix Of Florida Residential Building Energy Code And The International Energy Conservation Code (Iecc) 2006, Florida Solar Energy Center, Mangesh Basarkar

FSEC Energy Research Center®

This report presents a comparison of the differences between the Florida and the IECC (2006) residential energy code requirements. In addition to this summary, the documentation is divided into three sets of distinct comparisons: Comparison of Performance-based methods, Comparison of Prescriptive methods and Comparison of key provisions of the texts. In order to provide the best housing stock, with a code that is easy to implement and enforce, the final recommendation of the study was for Florida to maintain its own code, but consider incorporating some of the newer IECC measures.

An Initial Non-Equilibrium Porous-Media Model For Cfd Simulation Of Stirling Regenerators, Roy Tew, Terry Simon, David Gedeon, Mounir B. Ibrahim, Wei Rong

Mechanical Engineering Faculty Publications

The objective of this paper is to define empirical parameters (or closwre models) for an initial thermai non-equilibrium porous-media model for use in Computational Fluid Dynamics (CFD) codes for simulation of Stirling regenerators. The two CFD codes currently being used at Glenn Research Center (GRC) for Stirling engine modeling are Fluent and CFD-ACE. The porous-media models available in each of these codes are equilibrium models, which assmne that the solid matrix and the fluid are in thermal equilibrium at each spatial location within the porous medium. This is believed to be a poor assumption for the oscillating-flow environment within Stirling …

Compact And Low Loss Silicon-On-Insulator Rib Waveguide 90° Bend, Yusheng Qian, Seunghyun Kim, Jiguo Song, Gregory P. Nordin, Jianhua Jiang

Faculty Publications

A compact and low loss silicon-on-insulator rib waveguide 90° bend is designed and demonstrated. An interface realized by a trench filled with SU8 at the corner of a waveguide bend effectively reflects incoming light through total internal reflection (TIR). In order to accurately position the SU8-filled trench relative to the waveguide and reduce sidewall roughness of the interface, electron beam lithography (EBL) is employed while inductively coupled plasma reactive ion etching (ICP RIE) is used to achieve a vertical sidewall. The measured loss for TE polarization is 0.32 dB ± 0.02 dB/bend at a wavelength of 1.55 µm.

Evaluation Of The Effectiveness Of Blank-Out Overhead Dynamic Advance Warning Signal Systems, Ryan Peterson

Theses and Dissertations

Advance warning signals installed upstream of a high-speed signalized intersection (HSSI) warn motorists of impending signal changes in an effort to reduce the frequency of red-light running (RLR) and crashes. A new advance warning signal design was tested on an approach to an HSSI in Utah to study the effects of the modified design on motorist behavior. The new design utilized an overhead dynamic blank-out sign and flashers. A state-of-the-art digital wave radar evaluation system was installed at the study site to collect continuous data of vehicle speeds and RLR events by a non-intrusive method. Crash data were collected from …

Metastable Behavior Of Vortex Matter In The Electronic Transport Processes Of Homogenous Superconductors, X. B. Xu, Y. Liu, H. Fangohr, L. Zhang, Shichao Ding, Z. H. Wang, S. L. Liu, G. J. Wu, H. M. Shao

Faculty of Engineering - Papers (Archive)

We study numerically the effect of vortex pinning on the hysteresis voltage-temperature (V-T) loop of vortex matter. It is found that different types of the V-T loops result from different densities of vortex pinning center. An anticlockwise V-T loop is observed for the vortex system with dense pinning centers, whereas a clockwise V-T loop is brought about for vortices with dilute pinning centers. It is shown that the size of the V-T loop becomes smaller for lower experimental speed, higher magnetic field, or weak pinning strength. Our numerical observation is in good agreement with experiments.

Effect Of Stay-In-Place Metal Forms On Performance Of Concrete Bridge Decks, Stephen Litster Frost

Theses and Dissertations

The objectives of this research were to investigate the effect of stay-in-place metal forms (SIPMFs) on the performance of concrete bridge decks in Utah. The research program included six bridge decks with SIPMFs and six decks without SIPMFs, which were all located within the Interstate 215 corridor in the vicinity of Salt Lake City, Utah, and therefore subject to similar traffic loading, climatic conditions, and maintenance treatments, including applications of deicing salts during winter months. All of the tested decks were constructed between 1984 and 1989 using epoxy-coated rebar. Several tests were performed at each of six locations on each …

Fabrication Of Pdms (Polydimethylsiloxane) Microlens And Diffuser Using Replica Molding, Fang-Tzu Chuang

Fang-Tzu Chuang

This paper reports the fabrication method of PDMS (polydimethylsiloxane) microlens array based on the replica molding process, casting a liquid PDMS into concave microlens molds. Concave microlens molds were fabricated through spin-coating processes suspended a liquid PMMA film on the micro-drilled hole, leading to the formation of the special curvature. Then, PDMS microlens arrays and diffusers were fabricated by replica molding and discussed in this study. The fabricated microlenses have both good surface roughness and high-quality optical properties. Therefore, diffusers were fabricated by two-step replica molding. A high-intensity He–Ne laser beam was uniformly spread through diffusers. Experimental tests demonstrated that …