Engineering Commons^™

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 …

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 …

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 …

Study On Vortex Formation In The Pouring Basin By Direct Observation, J Runyoro

Tanzania Journal of Engineering and Technology (TJET)

Although the formation of vortex on the free surface of liquid draining from a container is often observed, relatively little is known about the phenomenon. When a liquid is drained from a container such as a bathtub through a bottom orifice, a dip on the surface known as vortex is formed. The vortex first appears as a small dimple in the free surface, which suddenly forms a cone-shaped hole. The vortex causes turbulences, which draws in air down into the orifice (drain). Generally, the issue of vortex formation is so common in our lives that possibly its occurrence seems to …

Suitability Of Crusher-Dust As Masonry Construction Material, John Makunza

Tanzania Journal of Engineering and Technology (TJET)

Crusher dust generated at Kunduchi quarries in Dar es Salaam during aggregate crushing is counted as a waste material, and some times it .is disposed away or sold at a cheap price of not more than a quarter of that of sand. A study on the use of the crusher dust as a building material has been carried out in which samples were collected and analyzed for grading (sieve analysis). In additional to that, other samples were stabilized with a small amount of cement, from which bricks were produced and tested for compressive strength. Other bricks were bonded together using …

Effectiveness Of Hot Isostatic Pressing On Healing Oxide Film Defects In Cast Aluminium Alloys, C Nyahumwa

Tanzania Journal of Engineering and Technology (TJET)

Hot isostatic pressing (hipping) of cast aluminium alloys is recognized as a means of providing improved internal soundness and mechanical properties of the castings. However, little is known about the limitations and potential benefit of the hipping process to produce reliable aluminium alloy castings containing oxide film defects due to turbulently filling of moulds. In this study, oxide film defects and fatigue lives of turbule''Zt filled unfiltered AI-7Si-Mg alloy castings have been characterised in as-cast and hipped. conditions to quantify the effectiveness of hot isostatic pressing on healing oxide film defects in the castings. The average fatigue life and fatigue …

Comparison Of Two Different Transport Models To Predict Sediment Transport: Simiyu River, Tanzania, Case Study, F Mwanuzi1

Tanzania Journal of Engineering and Technology (TJET)

This paper presents the results of a study which focused at the spatial and temporal characteristics of sediment transport and deposition in the main river channels and floodplains. Two different numerical models were used to simulate stream flow and to analyze sediment transport and deposition in the river channels: (1) the SMS modules RMA2 and SED2D and (2) the SCALDIS model developed at the Free University of Brussels. Both numerical models contain a two-dimensional hydrodynamic module and a sediment transport module, allowing simulation of stream flow and sediment transport processes in river channels. However, they differ in the following aspects: …

Overview Of Hydraulics And Simiyu River Sediment Input Into Magu Bay, Lake Victoria, Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

Lake Victoria is experiencing multifaceted environmental and ecological problems. A  study of the problems needs a multidisciplinary approach. to establish the cause-effect relationships. The study focuses on the hydraulics of Lake Victoria's Magu Bay and Simiyu riverine input of suspended sediments and their distribution in the Bay. Sampling in the river mouth and the Bay was conducted aboard an 8m outboard engine wooden boat. Turbidity, currents speed and direction were measured using an "AANDERAA" multi-sensor self-recording current meter model 9 (RCM9). Water depth was measured using an echo-sounder type FISHIN' BUDDY II. Geographical positions of the sampling locations were obtained …

Gasification Kinetics Of Ultrafine Coal Char Oxidation In Flame Reactions, G John

Tanzania Journal of Engineering and Technology (TJET)

Pulverized coal combustion is exceedingly complex with a  vast number of variables. In order to avoid the complications associated with the burning of coal char, a controlled study has been made of the oxidation of fine graphite in laminar methane-air flame as a contribution to the understanding of the more complex phenomena of the gasification kinetics of the char. The burning of methane is equivalent to the burning of volatiles and graphite oxidation is similar to that of coal char. Aspects of this have been simulated in experimental and computational studies of 4pm diameter graphite particle burning in methane -air …

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

The Decomposition Kinetics Of Solids Thermodynamic Evidence For The Enthalpy Driven Cooling Of Reaction Environment Part 2, Akwilapo D

Tanzania Journal of Engineering and Technology (TJET)

The analysis of non-isothermal kinetic data for the decomposition of calcium carbonate, CaC03 (s) ~ CaO (s) + C02 (g) in flowing nitrogen, shows that the decomposition of solids is accompanied by self-cooling/heating of the reaction environment depending on the sample mass and heating rate. The correctness of the kinetic model is established by the calculation of the enthalpy change of the reaction. This is the thermodynamic evidence of endothermic enthalpy driven cooling of the reaction environment. The enthalpy change LJH = 179.33 kJmol-1 estimated from this work for the dissociation of CaC03 is in agreement with LJH = 179.17 …

Investigation Of The Stability Of Engine – Governor System Operated At Low Speeds, Cuthbert Mhilu

Tanzania Journal of Engineering and Technology (TJET)

During diesel engine operation, a tendency for the engine not to achieve a  steady idling speed has often been observed. During idling speed the engine tends to either race or stall as a result of poor and incorrect metering of the fuel, which is required for the combustion process and if severe, the engine will stop firing completely. 111 this research an investigation was made to establish knowledge on diesel engine stability operated at low speeds. The influence of a governor of an engine in the control of the engine speeds has also been investigated. In order to obtain information …

Environmental Impact Of Wetland Resources Utilization In Simuyu Basin, Tanzania, Shadrack Mwakalila

Tanzania Journal of Engineering and Technology (TJET)

There is a growing appreciation of the natural functions of wetlands, and the values and different forms of uses that humans attach to them. Wise use and special conservation strategies are therefore needed in order to sustain their productivity. Wetlands are one of the most fruitful areas of archaeological research, and they are the ideal setting in which to study the interactions between physical processes and human actions that encapsulate and exemplify many of the themes of man's impact on his environment. But all these beneficial functions of wetlands seem to be in danger of being lost to draining and …

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.

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.

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 …

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 …

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.

A Short Tutorial On Reconstructability Analysis, Martin Zwick

Complex Systems Faculty Publications and Presentations

This talk will present the basic ideas of Reconstructability Analysis. RA is a general modeling methodology developed in the systems community since the early 60s (pioneered by Ross Ashby) for exploratory (data mining, machine learning) and confirmatory modeling. RA is based in graph theory, set theory, information theory, and statistics. It is applicable to qualitative (nominal) and, via binning, to quantitative (continuous) data, with both statistical & non-statistical applications. It overlaps and augments more widely known methods, e.g., log-linear modeling and Bayesian networks.

Keywords: Reconstructability Analysis, Log-Linear Modeling, categorical data, multivariate statistics, exploratory modeling, confirmatory modeling

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 …

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 …

A Comparative Study Of Various Loss Functions In The Economic Tolerance Design, Jehnan Pan, Jianbiao Pan

Industrial and Manufacturing Engineering

Engineering tolerance design plays an important role in modern manufacturing. In this paper, the Kapur's model was modified so that the economic specification limits for both symmetric and asymmetric losses can be established. Three different loss functions: (1) Taguchi's quadratic loss function; (2) Inverted Normal Loss Function; (3) Revised Inverted Normal Loss Function are compared in the economic tolerance design. The relationships between the three loss functions and process capability indices for symmetric tolerance are established. The results suggest that the revised inverted normal loss function be used in determination of economic specification limits.

Payback Information: It's Effect On Home Buyers Regarding Energy Efficiency, Steven E. Sparti

Theses and Dissertations

This study was conducted to find out how payback analysis would affect consumer decision making with regards to home energy efficient upgrade packages. Three different home plans were obtained from a local builder and seven different energy efficient packages were created. Using Hot2000 the heating and cooling loads were calculated for each building, with each energy efficient package, in each of the four major cardinal directions. The averages were taken and the payback information was calculated. The payback information included the increased cost of the package, the increase in the mortgage payment, the annual savings from heating and cooling bills, …

Refractive Indices And Band-Gap Properties Of Rocksalt Mg XZn Sub>1-XO (0.68 ≤X≤1), RüDiger Schmidt-Grund, Anke Carstens, Bernd Rheinländer, Daniel Spemann, Holger Hochmut, Gregor Zimmermann, Michael Lorenz, Marius Grundmann, Craig M. Herzinger, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

The room-temperature optical pseudo-dielectric-functions of single-phase, single-crystalline rocksalt-structure Mg_xZn_1-xO with Mg-content x between 0.68 and 1 were determined in the photon energy range from 0.75 to 9.10 eV using spectroscopic ellipsometry. The refractive index determined in the spectral region below the fundamental absorption edge decreases with increasing Mg content. The pseudo-dielectric-functions reveal structures caused in critical points due to electronic band-to-band transitions and free exciton formation at the fundamental band-gap transition. Standard model dielectric function approaches were applied for line shape analysis. Upon increase of the bond ionicity with increasing Mg content the energies of …

Instrumental Intensity Scales For Geohazards, Steven Kramer, Sarah B. Upsall

Geohazards

The relationship between ground motion characteristics and geohazard-related earthquake damage was investigated for slope instability, lateral spreading, settlement, and buried pipeline damage, and the results used to develop two instrumental intensity scales. The scales are based on three velocity-related ground motion parameters that reflect the amplitude, frequency content, and duration of a ground motion. The scales provide intensity values that are strongly correlated to potential damage – one scale expresses intensity on a 0-10 scale and the other in terms of an apparent earthquake magnitude. The former is expected to be particularly useful for rapid identification of potential damaged areas …

Expected Earthquake Losses To Buildings In Istanbul And Implications For The Performance Of The Turkish Catastrophe Insurance Pool, E. Durukal, M. Erdik, K. Sesetyan

Geohazards

The city of Istanbul will likely experience substantial direct and indirect losses as a result of a future large earthquake. This paper reports on the expected building losses in the city in terms of probable maximum and average annualized losses and discussed the results from the perspective of the compulsory earthquake insurance scheme operational in the country.