Mechanical Engineering Commons^™

Numerical Study Of Pneumatic Conveying Of Powders, Muhammad Mushahid Rafique Quereshi

Theses

The dense phase mode may be advantageous over the dilute phase mode, for some pneumatic conveying problems, because it causes less erosion of the pipeline, less attrition of the material, requires less dust collection and is effective even for smaller pipe diameters. The objective of this study is to numerically determine the parameters that govern the formation slugs in dense phase conveying. The distributed Lagrange multiplier/fictitious domain method (Glowinski et al. 1998 and Singh et al. 2000) is used to perform direct simulations of the motion of solid and gas phases in pipes with rectangular cross-sections. In this approach the …

Electrohydrodynamical Manipulation Of Particles Based On Dielectrophoresis, Oleksii Vasylyschuk

Theses

The movement of matter in a non-uniform electric field, termed dielectrophoresis, is of interest to scientists of various branches: physics, chemistry, engineering, and life science. To chemists and physicists it is a science of many varied phenomena. To engineers it is a source of new and useful techniques for separating materials or improving materials’ behavior. To ecologists it provides a major means of minimizing pollution. To life scientists it offers new ways to study and manipulate cells and their subparticles, and to help unravel the nature of living systems.

The purpose of this thesis is to concentrate on some aspects …

Implementation Of A Two-Dimensional Discrete Element Method To Describe Granular Materials Composed Of Elliptical Cohesionless Particles, Juan Jose Martinez Alvez

Theses

This work is aimed at developing a discrete element simulation that models the contact between elliptical grains or particles in granular materials. The goal is to implement an algorithm to carry out collision detection between ellipses as well as ellipsoidal objects. The practical issue here is that the real shape of macroscopic grains can be approximated better using elliptical curves than using spherical curves. In addition, the simulation model will also be valid for spheres, since these objects are special cases of ellipsoids.

An accurate contact detection algorithm was investigated by means of two different formulations. The first formulation determines …

Computer Simulation Of Automotive Disc Brake Noise, Vadims Milovs

Theses

Disc brake noise continues to be a major concern throughout the automotive industry despite efforts to reduce its occurrence. Many articles are written on this subject, but there still is no agreement on what exactly causes disc brake noise and what part of the braking system is responsible for it.

The goal of current research was to build a simplified but inclusive mathematical model of a disc brake system and investigate it using Matlab software. The twodimensional model including damping, Stribeck effect and stick-slip friction was built.

The model is unique in a way that all the similar models have …

Analytical And Fea Analysis Of Silicon Micro-Machined Capacitive Pressure Sensor, Eoghan O'Donoghue

Theses

This thesis is concerned with the electro-mechanical characterisation of MEMS capacitive pressure sensors and the determination of models to describe their behaviour.

The finite element software package ANSYS is validated as a tool for the examination of the electro-mechanical behaviour of capacitive pressure sensors. It is then used to incorporate the effects of applied load, voltage and residual stress into a model of the sensor structure. The capacitive pressure sensor is modelled both in 3D and also in 2D axis-symmetric modes. The error between the 2D and 3D models is quantified.

The behaviour of structures under electrostatic actuation is investigated. …

Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis

Theses

Photovoltaics are devices that convert sunlight directly to electricity. It is well established that the conversion efficiency of mono and poly-crystalline silicon-based photovoltaic modules is inversely related to their temperature. Substantial improvements in operational performance can thus be achieved if the thermal energy accumulating in the material can be effectively dissipated.

Accurate modelling of modules would allow possible methods of thermal dissipation to be evaluated, and as a crucial component of the model, the thermal properties of the constituent materials of PV modules needed to be known. Special consideration needed to be given to the interfaces between dissimilar materials and …

Finite Element Analysis And Testing Of An Inkjet Cartridge Die, Dylan Ryan

Theses

This project investigates the application of finite element and experimental analysis in the design and testing of silicon based semiconductor components. In a thermal inkjet printer the ink cartridge contains a print head (or die), the head fires numerous droplets simultaneously to form pixels and letters. The inkjet cartridge die consists of a thin film layer, containing the integrated circuits that make up the thennal inkjets, mounted on a polysilicon substrate structure.

A number of incremental changes to the design and manufacturing processes related to the manufacture of these inkjet cartridge dies is made. In past instances when changes were …

The Evolution Of The Long Term Performance Of Fiber Reinforced Composites Materials Based On Vinyl Easter Resin, Nasser Abdullah Ali-Al Ghailani

Theses

Fiber reinforced polymer (plastic) FRP composites are different from traditional

structural materials such as steel or aluminum since the an-isotropic nature of a Fiber _ reinforced composite material creates a unique opportunity of tailoring its properties according to the design requirements. With the accelerated change in the technological sphere, FRP composite materials

have taken a paramount importance in various structural applications, where they successfully replaced conventional materials such as steel. Such success is based on the advantages offered by composite materials such as a high strength to weight ratio. However one aspect that is still delaying full acceptance of these …

Atomic Force Microscopy Used To Determine The Young's Modulus Of Vascular Smooth Muscle Cells, Samuel C. Lieber

Theses

The Young's modulus of cultured mouse and rat vascular smooth muscle cells (VSMC) was measured with an atomic force microscope (AFM). The AFM can image the three-dimensional structure of biological cells in a physiological environment enabling real-time biochemical and physiological processes to be monitored at a resolution similar to that obtained for the electron microscope (EM). Cellular mechanical properties were determined by indenting the cell's body, and analyzing the indentation data with classical infinitesimal strain theory. This calculation was accomplished by modeling the AFM probe as a cone. as well as a blunted cone. The blunted cone geometry fits the …

Experiments With A Galton Board, Christopher Oshman

Theses

Galton boards have been used for over a half-century as a tool to illustrate the formation of Gaussian shaped distributions as well as the Central Limit Theorem. Here, the Galton board was used to study the spontaneous percolation of a particle through an ordered array of rigid scatterers. The apparatus that was designed and fabricated provided a means to release 1/8" diameter spheres one at a time in a controlled and precise manner at any location on the board. The three experimental variables used in these experiments were the particle material, the release height, and the board tilt. angle. The …

Current Requirements By Electro Hydrodynamic Filter Systems Under Shipboard Operation Conditions, Ravi Shankar Attri

Theses

An experimental study was performed to determine the current required by an ElectroHydrodynamic (EHD) filter system to clean contaminants from Diesel Engine Lubrication Oil under normal shipboard operation conditions. The amount of current at a set predetermined voltage, which together means Power, was needed in order to anticipate the power required to perform a Shipboard Site Test Evaluation of the EHD filter.

The filter uses the effect of dielectrophoresis to separate contaminants from the lubrication oil. The filter operates at two thousand volts (2KV ac-rms) and thus requires substantial current to energize its electrodes. This type of Power is not …

Flexible Manufacturing System Utilizing Computer Integrated Control And Modeling, Yahia Mohammed Al-Smadi

Theses

In today's fast-automated production, Flexible Manufacturing Systems (FMS) play a very important role by processing a variety of different types of workpieces simultaneously. This study provides valuable information about existing FMS workcells and brings to light a unique concept called Programmable Automation.

Another integrated concept of programmable automation that is discussed is the use of two feasibility approaches towards modeling and controlling FMS operations; the most commonly used is programmable logic controllers (PLC), and the other one, which has not yet implemented in many industrial applications is Petri Net controllers (PN). This latter method is a unique powerful technique to …

Active Noise Control Using Adaptive And Advanced Control Techniques, Michael O'Brien

Theses

The theory and application of Active Noise Control to remove irritating acoustic pollution from a variety of sources has and continues to receive significant attention from both theoreticians and practitioners.

While a classical acoustic noise problem is the rejection of acoustic tonal disturbances with the most common solution employed being the celebrated filtered-X LMS algorithm, this thesis shows that the presence of non-linearly induced harmonics at multiple frequencies of the original tone often results in poor performance of this algorithm. It is further found that the noise reduction at these problematic harmonics can be improved in a number of ways, …

Dynamic Friction Of Uhmwpe Angular Compliant Bearing For Joint Implants And Machinery, Max Roman

Theses

The feasibility of a unique design of orthopedic- joint implant is investigated. The work focuses on the dynamic friction characteristics of a new joint. This unique design can be also useful in machinery involving oscillating motion similar to that of the hip joint during walking. An elastomeric layer bonded behind the rigid acetubular cup can be beneficial in improving the durability of prosthetic implants. Angular compliance offered by the elastomeric layer reduces relative sliding between the surfaces, lowers contact stresses by distributing pressure more evenly, and reduces the possibility of incongruent loading conditions caused by misalignment. The application of a …

Mechanical Design Of The Heater Used In Near Infrared Filter, Jun Ma

Theses

This thesis presents a design and analytical process in the application of the heater used in a near infrared filter working in Big Bear Solar Observatory, CA. The objective of the project is to achieve the physics parameters for the filter, which will be used in the observation of the solar activity.

The most important part of this design is to keep a relatively fixed temperature inside the oven-like heater. The reason is that optical properties of calcite (kind of filter in telescope) are pretty sensitive to a tiny disturbance on inside temperature. This was the biggest issue in this …

To Research, Analyse And Install An Optimised Maintenance Management System For A Medium Sized Manufacturing Company: A Textile Company Case Study, Christopher O'Donoghue

Theses

Modern manufacturing is continually striving to ensure that products are made to higher levels of quality with faster lead times and at the lowest possible costs. Manufacturing production has never been more reliant on machines and automated processes than it is today. This thesis investigates the management philosophies that are in existence, which cater specifically for maintenance and maintenance related issues. Management philosophies such as Reliability Centred Maintenance (RCM), Total Productive Maintenance (TPM), Profit Centred Maintenance (PCM), asset management (AM), Predictive Maintenance (PdM), Condition Based Maintenance (CBM) and World Class Maintenance (WCM) have increased company profits by drastically reducing maintenance …

Gait Development For Use In Dynamic Gait Optimization Of Qudrupedrobot Walking, Mark Will

Theses

The ability of walking robots to operate in areas that are inaccessible to wheeled robots has lead to significant research in the field of gait development and optimization for these robots. In this particular study, a catalog of gaits for use in a dynamic gait optimization system to optimize the walking speed of the quadruped Arturo robot on flat terrain is developed. This catalog of robot gaits was developed using a genetic algorithm formulation; various combinations of the selection, mutation, and crossover operators were analyzed.

The Arturo robot was modified so that physical verification of the developed gaits could be …

Segregation And Flow Characterization In Vibrated Hopper, Thottiam P. Ravichandran

Theses

Experiments and numerical simulation studies were carried. out on vertically vibrated wedge-type hoppers containing binary mixtures for the present research. The studies focussed on segregation analysis of the hopper discharge and the characterization of flow pattern of the binary mixtures in sealed hoppers, over wide ranges of frequency and amplitude of acceleration to determine the effect of these parameters.

The results of segregation study show that vibration promotes segregation of the binary mixtures. However, increase in frequency was found to make the contents of segregated discharge more uniform. Also, increase in wedge angle seemed to help in reducing segregation.

The …

General Parallel-Leg Mechanism : Position Analysis, Hans Buus Gangwar

Theses

This thesis proposes to analytically express the positions of the legs (each leg has a length and two spin orientations) for a parallel leg mechanism in terms of a single variable. The only limitations imposed are the leg bases are all on the same reference plane and the tool orientation is normal to the mobile upper plate. This is done for a parallel leg mechanism having any number of legs. The variable chosen is the first leg's vertex position on the upper plate.

The state space is the space the configuration can occupy. By looking at a planar slice of …

The Development Of Design And Test Methodologies For Hovercraft, John Cronin

Theses

This project is concerned with the development of design and test methodologies for hovercraft.

Full-scale hovercraft field-testing is to be achieved through the dedicated re-design and re-construction of the ABl11Crossbow hovercraft. The Crossbow hovercraft is an experimental craft, which was built in England in the early seventies. The Crossbows re-design focuses on the production of a versatile craft, which is capable of modification to produce a variety of different operating conditions. The re-design and re-construction comprises several distinct areas. An improved and adjustable lift and thrust system is designed. The design and manufacture of a new more stable and versatile …

Interventions Of Water Jet Technology On Skin Surgery, Kittipat Vichyavichien

Theses

The perfect and precise surgical cut, similar to today's laser one, is very important in many surgeries, especially in dissection and to recanaize arterial occlusive lessions. Causing no coagulation is one of the advantages of water jet because it generates no heat. It also provides omni-directional cutting capabilities at very high speeds, resulting edge quality that is usually superior to other existing conventional cutting processes. Debris is always carried away from incisions by jet stream and less damaged tissue, than mechanical incisions. In addition, water jet exerts minimal contact pressure on the tissue being cut due to the small diameter …

Biomechanical Study Of Performance Of A Plugged Femoral Implant Coupled With A Trochanter Cable System Using Finite Element Analysis, Deanna Yvonne Carstarphen

Theses

A Finite Element Analysis was conducted to determine the effect of a plug on the performance of the critical section of a femoral implant coupled with a trochanter cable grip system. The critical section was defined near the proximal end of the stem where a hole was designed for the purpose of attaching the cable grip system. Two models were generated for the analysis. One consisted of the critical section with the grip cables and a plug filled in the hole and the other was without the plug. The models were based on design specifications provided by Howmedica Incorporated. Two …

Development Of Icejet Machining Technology, Dimitri V. Shishkin

Theses

This work was concerned with the application of ice powder for material processing. Material cutting and surface cleaning were also studied. As a result, innovative cleaning and etching technology was pioneered. The corresponding technology was designed and demonstrated.

The study involved investigation of water freezing, crushing of generated ice, ice transportation, formation of ice water and ice air streams and, finally, use of this stream for material cutting and cleaning. The theoretical work included investigation of the phase change in water and ice formation, effect of ice temperature on particles behavior and entrainment of ice particles by the water stream. …

System Simulation And Modeling Of Electronics Demanufacturing Facilities, Ketan Giridhar Limaye

Theses

Over the last decade, pressure on the electronic industry has been increasing as concerns for product take-back, product stewardship and global warming have continued to grow. Various end-of-life management options are being expanded including recycling to recapture values from basic materials through reengineering and recovery of subassemblies and individual components for remanufacturing. While progress has been reported on life cycle assessment (LCA), disassembly planning, design for disassembly, and design for environment (DFE), very little research has been focused on demanufacturing from a systems perspective.

The objective of this thesis is to build an interface between the user who knows the …

Evaluation Of Rotating Fluidized Bed As A Dry Coater, William Christopher Dunphy

Theses

Coating of particles is normally carried out with the use of environmentally unfriendly solvents. Development of dry coating methods is therefore quite important.

A Rotating Fluidized Bed was constructed, instrumented and verified as to operation. Twelve coating experiments were carried out with PMMA 200μm mean diameter as host and alumina 0.25μm primary particle size as guest with the RFB being operated in the fully fluidized range.

In all analyzed samples, coating was observed. Analysis was carried out on the qualitative basis by SEM and EDX.

An Investigation Of Polyethylene Bearing Wear Of New Jersey Lcs Knee On Cobalt Chromium And Titanium Nitride Types, Lei Wang

Theses

The total knee replacement systems (TKRS) are used for the treatment of osteoarthritis and rheumatoid arthritis. Excessive wear can substantially shorten their life span.

Two tests were performed to examine the wear characteristics of tibial bearings used in TKRS. Each test consisted of six sets of Anterior/Posterior Glide Tibial Bearings each with a conical control arm. The tibial bearings were all made by UHMWPE. Three of these bearings were mounted onto a Co-Cr alloy tibial platform and Co-Cr alloy LCS® femoral component. Another three sets of bearings were mounted onto a TiN tibial platform and TiN LCS® femoral component. They …

Object Oriented 3d Dynamic Simulation Of Flow Of Material Through Hopper, Krishnendu Roy

Theses

Development of object oriented 3D dynamic simulation of the particle is considered. This code is based on the soft sphere model dealing with both normal force , tangential force and the friction. The development of such a model and the code is motivated by the need to understand the flow patterns of granular material. The prime effort while developing this code was focused on the data encapsulation and secured access to all the attributes of all physical parameters of the bulk solid, which might be endangered by the random access of the interface of the software. A dynamically bound array …

Tools For The Design Of Flexible Manufacturind Systems, Prashant A. Patel

Theses

Flexibility in manufacturing systems can broaden the horizons for a company. But the means for achieving it are far more critical. This trend is created by the increase in competitiveness, growth of technology along with demand variations, more customization, and short product life cycles. But "Flexible Manufacturing Systems" to most of the manufacturers sounds like a synonym for automation.

A real Flexible Manufacturing System is designed when every unit of the company is synchronized in such a way to respond in a harmony to any changes that come against it. Fine-tuning of each and every part of the company is …

Design Of An Effective And Timely Product Development Process For Medical Devices, Jean Benoit Almonor

Theses

Effective product development process is one of the most critical issues facing medical devices manufacturing today. There is a need to search for ways to improve or solve the cross organization and company boundaries to enhance the faster release of new medical products to the market. This thesis presents an integrated set of perspectives on the process of new product development of medical devices with dual goals of achieving marketing speed and meet customer satisfaction.

The Attribute Driven Specifications approach described in this thesis, is one of the most valuable tools in the approach to effective product development in medical …

Demanufacturing Metrics For Industrial Fasteners And Disassembly Process, Narendra P. Raj

Theses

As the society progresses towards ecological maturity, the issue of reducing the environmental burden imposed by used products becomes increasingly important Environmental issues are becoming increasingly relevant for product designers and manufacturers. Public awareness of the value and fragility of an intact ecology is constantly growing, and the traditional assumption that the cost of ecological burdens to be shared by a society, as a whole is no longer accepted. Environmental protection legislation requiring manufacturers to "take back" and recycle used products will be a commonplace throughout Europe and the U.S. in the near future.

Demanufacturing involves separating and disassembling a …