Mechanical Engineering Commons^™

Discrete Element Simulation And Nonlinear Dynamic Analysis Of Particles In A Simple Lattice Structure, Liam E. Buckley

Theses

The study of particles interacting in lattice structures allows for insight into the complex interactions of granular flow, and the adaptation of such structures to mechanical apparatuses to handle the separation of bulk particulate matter. Applying methods of computer analysis to the interactions taking place within the particle-lattice system provides a particle level methodology to the study of the phenomenon taking place, as well as a stepping stone for future design of related devices.

A two prong approach is presented to the study of such particle-lattice systems. The first approach is composed of adapting an existing discrete element computer code …

Ultrasonic Flowmeters In Determination Of Correlation Functions Of Velocity And Ultrasound Wave Fluctuations In Grid-Generated Turbulence, Tatiana A. Andreeva, William W. Durgin

Office of the Provost Scholarship

The paper is devoted to the experimental investigation of the statistical characteristics of the grid-generated turbulence produced in a wind tunnel. Ultrasonic time-of-flight method using dual transducers is utilized to develop a methodology for determination of the correlation functions of turbulent velocity and sound speed fluctuations. The ultrasonic flowmeter equation is considered in the form that includes effects of turbulent velocity and sound speed fluctuations. The influence of temperature inhomogeneities on ultrasonic wave propagation is investigated using a set of experiments with a heated grid. Utilization of high-speed digital data acquisition cards and LabView software for the experiments allows collecting …

Comparison Study Of Cooling Fins And Chills Effectiveness In Aluminum Sand Mold Casting, Vladimir E. Kouznetsov

Graduate Research Papers

Besides proper design of gating and risering systems, there are several methods used to control and modify solidification behavior of cast alloys. Within these methods, the most widely used are local cooling aids employing cooling fins (thin segments attached to problematic areas of casting) or external chills (metal inserts placed into mold walls to accelerate heat withdrawing from potential hot spot). The later helps to promote directional solidification when traditional methods are not possible to use due to limitations related to the casting design. Despite relatively wide application in aluminum foundries, there are no specific recommendations on cooling aids parameters …

Designing Active Smart Features To Provide Nesting Forces In Exactly Constrained Assemblies, Eric Pearce

Theses and Dissertations

Ever since the design and manufacture of products moved from the craftsman era where individual craftsman designed and manufactured the entire product, to the mass production era, where skilled laborers were crafting interchangeable parts or in some cases single features on interchangeable parts, variation in assemblies has been a major concern to designers, manufacturers, and in a more subtle way, customers. Variation, in the end, affects quality, performance and the cost of products. One particular type of design that is particularly robust to variation is an exactly constrained design.

Several researchers have recently explored the topic of exact constraint design. …

Microstructure Sensitive Design Of An Orthotropic Plate Subjected To Tensile Load, Brent L. Adams, Mark Lyons, Joshua R. Houskamp, Surya R. Kalidindi

Faculty Publications

Financial support for this work was provided by the Army Research Office, Proposal No. 42566-MS, Dr. David Stepp, Program Director and Army Research Lab, Dr. Scott Schoenfeld, Point of Contact. Microstructure Sensitive Design (MSD) is a newly developed mathematical framework that facilitates rigorous solutions to inverse problems in microstructure design of materials. In this paper, this methodology is applied to an orthotropic thin plate containing a circular hole subjected to an in-plane uniaxial tensile load. The primary design objective is to maximize the load carrying capacity of the plate while avoiding plastic deformation in the plate. Making use of the …

Universal Mounting Bracket For Laser Targeting And Feedback System, Richard J. Kelin Ii

Patents (University of Northern Iowa)

A support bracket for mounting a device such as a laser targeting and feedback system to a spray gun. The bracket includes a bolt having a threaded end, a first collar disposed on the bolt opposite the threaded end and a second collar threadably engaged with the threaded end of the bolt. A compressible member is disposed on the bolt between the collars. Opposite the compressible member, a support arm used to support the device is attached to the second collar. The bracket is engageable with a portion of the spray gun body and is engaged therewith by deflecting the …

Using Satellite Imagery To Evaluate The Impact Of Urban Forest On Summertime Residential Electricity Consumption In Terre Haute, Indiana, Usa, James R. Boulton

All-Inclusive List of Electronic Theses and Dissertations

Urban areas are horne to a large portion of the population of the United States and also a significant portion ofthe nation's forest resource. This urban forest contributes to the richness of the urban lifestyle in many ways, including aesthetic improvements, cleaning and protecting air, land, and water resources, and reducing the urban heat island effect. This thesis studies the degree to which energy reduction attributable to the urban forest can be determined using remotely sensed data. Results showed a slight inverse relationship between urban forest density and energy usage, meaning that as the density of trees increases there is …

Signal Mast Arm Fatigue Failure Investigation, Genda Chen, Michael G. Barker, Lokeswarappa R. Dharani, Christopher W. Ramsay

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Missouri Department of Transportation (MoDOT) has discovered and documented failures in several cantilever mast arms in the recent years. The failures were primarily by fatigue at the weld of the arm to the base plate attached to the mast. With over 6000 mast arms in service in Missouri, the failures raised concerns with the existing mast arm inventory and future mast arm design. This report presents findings from an effort to determine the cause of unexpected cracking in Missouri mast arms. Three causes of premature failure were investigated: the stress ranges experienced at the weld detail were higher than …

Thermoacoustic Refrigerator, Nathan A. Hammond

Undergraduate Honors Capstone Projects

Thermoacoustic refrigerators have typically been designed to cool an isolated working fluid, necessitating a heat exchanging device to draw heat from the outside target fluid into the cooled working fluid. For example, a thermoacoustic refrigerator designed to chill air might utilize argon as an isolated working fluid, necessitating a heat exchanger to draw heat from the air to the argon. A second heat exchanger would be required to draw heat from the argon to a cold sink.

A design team at Utah State University has created a thermoacoustic refrigerator which uses air at atmospheric pressure as its working fluid. By …

Development Of New Heat Sink Technology For High-Density Microprocessors, Pedro Lopez Jr.

Theses and Dissertations - UTB/UTPA

This study investigates the performance of existing heat sinks and compares it with two heat-exchanger prototypes: aluminum-foam heat sink and PCM (phase-change material)-filled heat sink. Kapton flexible heaters are used to replicate the heat produced by a computer's CPU (central processing unit). A number of thermocouples are connected between the heater and the heat sink being used to measure the component's temperature. The thermocouples are also connected to a data acquisition card to collect the data using a LabVIEW program. The values obtained are compared to data published in literature to validate the experiments and the setup. This setup is …

Analysis Of Lifting Performance Capacity Through An Integrated Learning Curve Model, Jose Roel Flores

Theses and Dissertations - UTB/UTPA

Physical fitness specific to job demands is necessary for jobs that require moderate or heavy effort. Fitness training is needed not just when a new job is learned but also when an individual has been away from the job for a few weeks and returns to perform the task. The basic problem is to have a good understanding of the dynamics of performance capacities to establish training and retraining regimes to prevent overexertion. To obtain this, a better understanding of the behavior of performance capacity over time is necessary. A performance capacity training regimen was designed for tasks that required …

Analysis Of Performance Capacity Of Hand Grip Through An Integrated Learning Curve Model, Miguel Torres

Theses and Dissertations - UTB/UTPA

There are few activities or work task in the manufacturing industry that does not involve grip strength. That is why it is in the best interest of the manufacturing industry to have an understanding of the optimum grip strength gain capacity over time that would lead to better performance, accuracy and most of all prevent hand grip related injuries. For that reason, this thesis was concentrated in discovering a possible basic working model for estimating grip strength over time for a specific grip strength activity. The first step was to observe the trend characteristics of the strength gain data over …

Expert System Development For Hard Disk Drive Failure Analysis, Fernando Rodriguez Rosas

Theses and Dissertations - UTB/UTPA

The Computer's Hard Disk Drive is a complex high technology device, diagnosis of a failure is difficult even using sophisticated test equipments. These Drives are expensive and returning a new one when it fails within the warranty period is not an option. The failed drive must be tested and repaired. In the repair process the analysis and diagnosis of the failures is a key point in the process where decisions regarding the repair process that the failed Drive will follow. Therefore, there is a requirement to perform an effective analysis and provide an accurate diagnosis. The standard system utilized for …

Human Reliability Analysis In The Performance Of Advanced Cardiac Life Support Tasks, Lucia Veronica Rosas

Theses and Dissertations - UTB/UTPA

Error reduction in the performance of medical emergency situations is an area of great concern in today's society. This is specially the case when the situation involves a cardiac arrhythmia. These situations are generally categorized as Advanced Cardiac Life Support (ACLS) events. The American Heart Association provides the proper procedures that practitioners of ACLS should follow to provide care to patients presenting heart arrhythmia problems. These situations occur inside and outside the hospital, outside the hospital being the most critical ones considering the limitation of equipment and availability of qualified care. Errors made by the practitioners of ACLS in this …

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (Feb. 01 – Apr. 30, 2003), Yingtao Jiang, Bingmei Fu, Woosoon Yim

Transmutation Sciences Materials (TRP)

We received most of the components, everything except the customized and outsourced stirrer, for the new apparatus for oxygen measurement/calibration. Thus far, most of the machining work has been completed. The LaveView module used for the data collection and the control of the apparatus has been tested. 2-D simulation work has been performed using FEMLAB.

Solvent And Method For Extraction Of Triglyceride Rich Oil, Shubhender Kapila, Paul Ki-Souk Nam, V. J. Flanigan

Chemistry Faculty Research & Creative Works

The present invention relates to a solvent for use in extracting oil from an oil bearing material, such as soybeans, with the solvent resulting in the selective extraction of a triglyceride rich oil, which contains 95% or greater triglycerides and non-polar constituents, with the solvent comprised of a hydrocarbon, preferably hexane, and a fluorocarbon, so that the solvent has a viscosity less than 2.6 centipoise and a polarity of less than 0.1. The present invention also relates to a method of using the solvent to extract the triglyceride rich oil, with the method including preferably extracting the oil at a …

The Pseudo-Rigid-Body Model For Dynamic Predictions Of Macro And Micro Compliant Mechanisms, Scott Marvin Lyon

Theses and Dissertations

This work discusses the dynamic predictions of compliant mechanisms using the Pseudo-Rigid-Body model (PRBM). In order to improve the number of mechanisms that can be modeled, this research develops and identifies several key concepts in the behavior of beam segments where both ends are fixed to a rigid body (fixed-fixed flexible segments). A model is presented, and several examples are discussed. The dynamic behavior of several compliant segments is predicted using the PRBM and the results are compared to finite element analysis and experimental results. Details are presented as to the transient behavior of a typical uniform rectangular cross section …

Reconstruction Of The Temperature Profile Along A Blackbody Optical Fiber Thermometer, David Gary Barker

Theses and Dissertations

A blackbody optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber forms an isothermal cavity, and the emission from this cavity is approximately equal to the emission from a blackbody. Standard two-color optical fiber thermometry involves measuring the spectral intensity at the end of the fiber at two wavelengths. The temperature at the sensing tip of the fiber can then be inferred using Planck's law and the ratio of the spectral intensities. If, however, the length of the optical fiber is exposed to elevated temperatures, erroneous temperature …

Design And Fabrication Of A Microscale Joule -Thomson Refrigerator, Lionel Gamini Hewavitharana

Doctoral Dissertations

A simple thermodynamic, heat transfer, and fluid flow model was developed for microscale Joule-Thomson refrigerators (JT devices). For a given geometry, the model predicted that the cooling capacity of the refrigerator increased with the inlet refrigerant pressure. The effectiveness of the JT device also increased with the inlet pressure, and the heat exchanger channel length. At a constant inlet pressure, the effectiveness, and the refrigeration capacity of a given JT device increased as the aspect ratio of heat exchanger channels was increased. For nitrogen refrigerant, the model predicted that it was possible to obtain approximately 250 mW of refrigeration capacity …

Two Dimensional Numerical Simulation Of Highly-Strained Hydrogen-Air Opposed Jet Laminar Diffusion Flames, Kyu C. Hwang

Mechanical & Aerospace Engineering Theses & Dissertations

In this study, a detailed 2-D numerical technique is utilized to investigate the structure, and flame extinction and restoration characteristics of laminar hydrogen-air opposed jet diffusion flames, using both plug (uniform) and parabolic inflow boundary conditions for 3 millimeter jet tubes, spaced 6 millimeters apart and imbedded in low velocity coflows.

First, by using the most recent of two chemical kinetic models, excellent agreement was obtained between calculated distributions of temperature and major species, and published UV laser Raman scattering measurements, for 50% and 100% hydrogen-air flames over a range of input strain rates. Agreement with measured OH profiles was …

Numerical Studies On Supersonic Mixing And Combustion Phenomena, Tarek M. Abdel-Salam

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical study is conducted to investigate the mixing, combustion, and flow characteristics of different scramjet-combustor configurations. Three-dimensional models for the combustors have been used. Numerical results are obtained using a finite volume computational fluid dynamics (CFD) code with unstructured grids with sizes between 200,000 and 400,000 cells.

In the first part of the current study, the effects of the side angle of the fuel injectors in both mixing and combustion processes are investigated. Raised (compression) and relieved (expansion) wall-mounted ramps are used with side angles of 0 (unswept), 5, and 10 degrees. Results are obtained for nonreacting flows as …

2003 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2003.

Screw Dislocation Interacting With Interface And Interfacial Cracks In Piezoelectric Bimaterials, Xiangfa Wu, Steve Cohn, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

Interface and interfacial cracks interacting with screw dislocations in piezoelectric bimaterials subjected to antiplane mechanical and in-plane electrical loadings are studied within the framework of linear piezoelectricity theory. Straight dislocations with the Burgers vector normal to the isotropic basal plane near the interface or interfacial crack are considered. The dislocations are characterized by a discontinuous electric potential across the slip plane and are subjected to a line-force and a line-charge at the core. An explicit solution for the screw dislocation in piezoelectric bimaterial with straight interface is found based on the solution of a similar problem for infinite homogenous medium. …

Study About High Influence Doping To Base Resistance And Bandgap Narrowing At Si/Si1-Xgex/Si Heterojunction Bipolar Transistor, Achmad Fadhol

Makara Journal of Technology

Study About High Influence Doping to Base Resistance and Bandgap Narrowing at Si/Si1-xGex/Si Heterojunction Bipolar Transistor. Heterojunction is a link formed bedween two semiconductor materials and differend bandgap which has thinness under 50nm and grow the mixture of plate SiGe as bases. The link is an abrupt link or graded one. In this research learnt formulation of doping concentration influence to basis resistance and bandgap narrowing through Si/Si1-xGex/Si Heterojunction Bipolar Transistor with abrupt emitter-basis link, besides taking care to mobility and basis wide to basis resistance, it is also influence of mole fraction to bandgap power. From the result shows …

Photocatalytic Treatment Of Heavy Metal Waste Cr(Vi) Withtio2 Photocatalyst, Slamet Slamet, Riyadi Syakur, Wahyu Danumulyo

Makara Journal of Technology

Photocatalytic Treatment of Heavy Metal Waste Cr(VI) with TiO2 Photocatalyst. The photocatalytic reduction of hexavalent chromium/Cr(VI) using TiO2 and copper-doped TiO2 as photocatalysts have been studied in stirred tank and circulating photoreactors. All photocatalysts were characterized with FTIR (Fourier Transform Infra Red), BET (Brunauer-Emmett-Teller), XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope). TiO2 Merck and Degussa P-25 are the commercial photocatalysts used to compare the photocatalytic activity of all the prepared catalysts. Blank test experiments as well as the effect of dopants, EDTA (ethylenediaminetetraacetic acid) and activated carbon addition were studied. Cr(VI) reduction on various pH and initial Cr(VI) concentration …

Development And Analysis Of Geographic Information System For Electricity Network (Case Study: Surabaya Industrial Estate Rungkut In Surabaya)., Lilik Jamilatul Awalin, Bangun Muljo Sukojo

Makara Journal of Technology

Development and Analysis of Geographic Information System for Electricity Network (Case Study: Surabaya Industrial Estate Rungkut in Surabaya). Geographic Information System (GIS) is a system of data which has spatial base. This may be cause has ability to process and analysis data quickly. The ability of GIS will be able to process the alternative in decision making. The need of electric power grows until recent time along with the existence of industrial sector expansion and land use expansion claim better service, large and balance stock of electric power. GIS is a solution for planning and managing data base system, for …

Application Of Remote Sensing And Geographic Information System Methods For Land Using Difference, Bangun Muljo Sukojo, Diah Susilowati

Makara Journal of Technology

Application of Remote Sensing and Geographic Information System Methods for Land Using Difference. Land using difference analysis has been done using remote sensing and Geographic Information System (GIS) methods. Identification of land using difference was conducted using map overlaying process of 1990s (digitized scalling 1:50.000) and 1997s land using map (interpreted from Landsat TM (Thematic Mapper) Image 1997) with UTM (Universal Transverse Mercator) coordinate. Image enhancement was done through histogram equalization with supervised classification devided into 7 classes: rice field, settlement, dry field, industry, pond, sport field and bush. Land using difference and river pollution BOD (Biological Oxygen Demand), COD …

Phase Composition Analysis Using Rietveld Methode And It's Influence To The Hardness Of Ti-Si-N Nanocomposites, Keba Moto, Lia Setiarini, Zufar Abubakar

Makara Journal of Technology

Phase composition analysis using rietveld methode and it’s influence to the hardness of Ti-Si-N nanocomposites. XRD data of nanocomposites Ti-Si-N have been analysed using GSAS based on Rietveld Method in order to identify phases and their composition as well as its influence on the hardness of these nanocomposites. Several new phases have been found in the sample beside the nc-TiN/a-Si3N4& a-/nc-TiSi2 that have been known widely. From the obtained crystalline phase, after the calculation of amorf Si3N4 and TiSi2 phase fraction, it is found that the optimum hardness can be reached when the fraction of a-Si3N4 phase around 8 wt.%

Influence Of Strain Rate And Temperature Of Hot Tension Testing On Mechanical Properties Of Medium Carbon Steel S48c, Dedi Priadi, Iwan Setyadi, Eddy S. Siradj

Makara Journal of Technology

Influence of Strain Rate and Temperature of Hot Tension Testing on Mechanical Properties of Medium Carbon Steel S48C. The characterization of S48C by hot tension testing was done to understanding the influence of temperature and strain rate for S48C flow stress, that close relationship with its forge ability. The hot tension testing was performed on temperatures and strain rates variation (T 850, 900, 950 0C and έ 0,01;1 s-1). The result of hot tension testing showed that increasing temperature decreases ultimate tensile strength (UTS) and flow stress of S48C. The higher decreasing of UTS is on 950 0C about 85% …

A Growth Mixture Theory For Cartilage With Application To Growth-Related Experiments On Cartilage Explants, Stephen M. Klisch, Silvia S. Chen, Robert L. Sah, Anne Hoger

Mechanical Engineering

In this paper, we present a growth mixture model for cartilage. The main features of this model are illustrated in a simple equilibrium boundary-value problem that is chosen to illustrate how a mechanical theory of cartilage growth may be applied to growth-related experiments on cartilage explants. The cartilage growth mixture model describes the independent growth of the proteoglycan and collagen constituents due to volumetric mass deposition, which leads to the remodeling of the composition and the mechanical properties of the solid matrix. The model developed here also describes how the material constants of the collagen constituent depend on a scalar …