Mechanical Engineering Commons^™

Synthesis And Characterization Of Birnessite And Cryptomelane Nanostructures In Presence Of Hoffmeister Anions, Marcos A. Cheney, Robin Jose, Arghya Banerjee, Pradip K. Bhowmik, Shizhi Qian, Joseph M. Okoh

Mechanical & Aerospace Engineering Faculty Publications

The effect of Hoffmeister anions Cl(-), SO(4) (2-), and ClO(4) (-) on the structure and morphology of birnessite and cryptomelane-type manganese dioxide nanostructures, produced by the reduction reaction of KMnO(4) and MnSO(4) in aqueous acidic media, was studied. The syntheses were based on the decomposition of aqueous KMnO(4) in presence of HCl for birnessite-type and acidified MnSO4 for cryptomelane-type manganese dioxide under soft hydrothermal conditions. They were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) techniques. XRD patterns show the formation of birnessite for the first synthesis and a mixture of cryptomelane and …

System Design And Integration For Repeated Impact Tests, Cheng Lin, Gene Hou, Sebastian Bawab, Timothy Coats, Hesham Nassar

Engineering Technology Faculty Publications

The design and integration of an impact-testing machine is particularly for the test of an object which is repeatedly dropped down from a specified height. Four linear actuators with two on each of the two magnetic rails are used to lift up an object weighing up to 70 lbs. Each actuator is powered and controlled by an industrial amplifier. A Programmable Logical Controller (PLC) is applied to activate these four actuators simultaneously and repeatedly. Accelerometers using an National Instruments (NI) data acquisition system are used to measure the impact force during the tests. Students gain design and implementation experiences from …

Selection Of Pressure Equation For Preliminary Planing Hull Design Using Modified Analytical Hierarchy Process, Pamela Sue Fergen

Mechanical & Aerospace Engineering Theses & Dissertations

In the early stages of design when data availability is limited, engineers often times rely upon experience and regression analysis to select the most suitable design equation among many competitive ones. This study presents an alternative that applies a modified Analytical Hierarchy Process (AHP) to select the most suitable design equation. The Analytical Hierarchy Process, a multi-criteria decision making method, has been utilized in the business and management world to collect and evaluate experts' opinions in order to arrive at a final decision. The Analytical Hierarchy Process employed here will treat each of the design equations as an expert and …

Analysis Of Possible Use Of Identification Technologies In Disassembly, Vukica Jovanović, Sreten Filipović, Gordana Ostojić, Stevan Stankovski, Milovan Lazarević

Engineering Technology Faculty Publications

The barcodes and Radio Frequency Identification tags that are being used during manufacturing, assembly, warehousing, and distribution could also be reused at the end of the product lifecycle for an identification of the correct disassembly process that would result in recycling of its components. The barcodes or RFID tags can be helpful in identifying objects in terms of sustainable development, regarding disassembly, recycling and reuse. In this paper, the analysis of the current applications of RFID Technology in the final phase of the product lifecycle will be presented. The simulation of the disassembly process supported by both barcode and RFID-enabled …

Simulation Based Six-Sigma Design For Service Industry, Shantanu Dhananjay Ghate

Mechanical & Aerospace Engineering Theses & Dissertations

The main purpose of this thesis was to develop the dental clinic design using six-sigma principles. Simulation software called Process Model^TM was used to build a primary layout of the clinic. Once the basic design was built, statistical analysis method like D.O.E (design of experiment) was used to generate the data based on different combinations of design parameters viz. number of hygienists, number of x-ray machines and waiting room capacity. These data were further analyzed using Contrast-Effect method, ANOVA and Regression Analysis. In order to incorporate the impact of random factors, Taguchi's methodology was applied. This lead to the …

Parameter Estimation Of The Arterial System, James Charles Carter Ii

Mechanical & Aerospace Engineering Theses & Dissertations

There are a number of disorders that originate from or involve faulty operation of the cardiovascular system. Diseases such as atherosclerosis, diabetes and hypertension can have a debilitating effect on blood flow. This makes the tools for simulating the effects of such diseases on blood flow important. Measures, such as pulse wave velocity, that are generated by models of the cardiovascular system can be important indicators of cardiac health. Although physically measurable, obtaining some parameters comes with a high cost and discomfort to the patient. Models can provide an assessment of many important parameters. The purpose of this project was …

Virtualization Of Physical Experiments Using Real-Time Data Generation From A Computational Fluid Dynamics Code, Kaustubh A. Dharwadkar

Mechanical & Aerospace Engineering Theses & Dissertations

This work presents a methodology for mapping physical experiments into real-time, web-based virtual experiments. The four broad elements included in the physical-to-virtual experiment transformation methodology are: (a) computer solution of conservation equations of mass and momentum to generate velocity and pressure (virtual) data that serve as the foundation for recreating the physical phenomenon in the virtual domain; (b) use of virtual pressure and velocity sensing devices to generate signals or readings from computed virtual data that can be observed and read on a computer screen; (c) use of visualization software such as Macromedia FLASH to create a highly interactive environment …

Development Of Comprehensive Agility Measurement Tool, Ameya Surendra Erande

Mechanical & Aerospace Engineering Theses & Dissertations

This research focuses on the development of Comprehensive Agility Measurement Tool. Industry independent use of such a tool would help enterprises benchmark their success in achieving agility.

Continuous improvement and modernization of manufacturing techniques around the globe have brought many mutations in manufacturing industry. Customer expectations and demands are behind the introduction of new paradigms such as mass production, lean, mass customization, agile and now internet-based manufacturing. Though lean was first coined with respect to manufacturing industry, soon it became applicable in all the industries based on its waste reduction and productivity improvement techniques. Lacking international competitiveness of US manufacturing …

A Markov Based Model For Maintenance And Repair Of Equipment, Deepa Jaishankar

Mechanical & Aerospace Engineering Theses & Dissertations

The failure repair process of a continuously operating device is studied in this research. Different cases that incorporate modeling of equipment deterioration, inspection, and maintenance for optimal maintenance policy are proposed. Markov processes are used to determine state probabilities, and the optimal value of the mean time to preventive maintenance is determined by maximizing the availability of the equipment with respect to the mean time preventive maintenance. The approach uses models that assume that equipment can fail due to both deterioration and random failures. Preventive maintenance can be performed from each working state to avoid deterioration failure. Economic effects are …

Development Of A Technique To Diagnose Subtalar Joint Instability, Ajaya Dhakal

Mechanical & Aerospace Engineering Theses & Dissertations

Most patients escape diagnosis of subtalar joint instability for years before treatment. Therefore, a clinically relevant technique to diagnose subtalar joint instability will improve its management. Towards this goal, a six degree of freedom positioning and loading device was developed to apply physiologic loads to the hindfoot. Because the ideal loading configuration to detect subtalar joint instability is unknown, the device was designed to apply rotational and translational forces simultaneously. Specifically, plantarflexion/dorsiflexion, inversion/eversion, and internal/external rotation can be applied individually or as coupled motions along with an anterior/posterior drawer. Kinematic data were collected from calcaneus, talus and tibia using a …

Failure Repair Model For A Device Using Minor And Major Maintenance Strategies, Hrishikesh Raman Phadke

Mechanical & Aerospace Engineering Theses & Dissertations

The major objective of this research was to study the maintenance decision process for systems with economic dependency. A probabilistic model was developed according to the proposed Markov model. After determining the maintenance cost through the markov models, we introduced the other costs associated with the device like operating cost and capital recovery cost, to get the total cost of all the activities involved in keeping the device. The optimal equivalent uniform cost can be found to occur at a particular number of life stages in the system. The nature of the equivalent uniform cost curve is dependent upon the …

Experimental Analysis And Modeling Validation Of A Knee Brace In Shock Mitigation, Manish Prakash Dhekane

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental setup simulating the dynamic environment in a high sea state is developed for the lower extremities to study the mitigation of shock impact. A single degree of freedom machine is equipped with six linear induction motors to produce impact acceleration ranging from 0.5G to 4G. The experiments are carried out along the dummy leg by using two configurations, one without a knee brace and one with a knee brace. Force and acceleration data is collected using a data acquisition system.

To develop the analytical model of the same experimental setup, the knee brace and dummy leg were scanned …

Disassembly Planning And Costing Through Petri Net Approach, Chunhsi Lei

Mechanical & Aerospace Engineering Theses & Dissertations

In the current consumer oriented environment, many new products appear in the market almost on a daily basis. Lured by advertisements and tempted by new product features, customers are constantly purchasing newer products. Acquiring newer products for often leads to throwing out older ones, but it is a totally different story for manufacturers. They need to consider the best way to reuse a product both for economic purposes and for environmental protection. Considerations for them often include: how to minimize total disassembly cost, how to achieve the lowest total disassembly time at each processing step, and how to sort valuable …

Optimum Preventive Maintenance By Markov Processes, Wen-Chun Chung

Mechanical & Aerospace Engineering Theses & Dissertations

The objective of this thesis is to carry out a maintenance cost analysis for a part that is subject to both random failure and deterioration failure. The analysis follows the guidelines of preventive maintenance and leads to a means of finding out the total cost of the maintenance procedure based on different maintenance cost data. The maintenance model developed in this thesis is based on a Markov Process, and its optimization is derived from a maximization of the availability of the part.

A case study was used to demonstrate the method for obtaining the optimal minimal preventive maintenance rate, steady …

Development And Validation Of Hardware To Measure The Load-Deflection Characteristics Of Any Material, Manish Govardhanrao Kalmegh

Mechanical & Aerospace Engineering Theses & Dissertations

A portable device to measure load-displacement will have applications in biomechanics and reverse engineering in the automotive and aerospace industries. Hardware was developed by attaching a load cell (LC 201, Omegadyne, Inc., Sunbury, Ohio) to a Faro Arm (Faro Technologies, Lake Mary, Florida), a portable coordinate measuring machine that accommodates standard and custom end effectors. A LabVIEW (National Instrument, Austin, Texas) program was developed to process the load cell and deflection data obtained from the Faro Arm. To validate this system, a four-inch square block, chair cushion, and head restraint of a car were tested using a material testing machine …

Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya V. Deodhar

Mechanical & Aerospace Engineering Theses & Dissertations

A dynamic model for the vehicle-guideway coupled with a controller is developed using dynamic modelling software, MADYMO. The fundamental characteristics of the vehicle are obtained from detailed FE analysis in NASTRAN. The vehicle is then converted into a 21-degree-of-freedom rigid body system with 12 FE magnets. A two span concrete guideway of 54 meters in length is modelled using 3D solid Hex8 elements. The air gap is modelled as a penetration of the magnets in the guideway. The PD controller aims at achieving constant penetration (i.e. the air gap) of all magnets in the guideway, throughout the simulation. This PD …

The Effect Of Hans Device On Brain Pressure Values In Finite Element Brain Models, Mihir M. Jawale

Mechanical & Aerospace Engineering Theses & Dissertations

A parametric study of behavior of different brain material properties when exposed to a mid-high severity pulse is presented. Few studies have considered brain pressure as a parameter to study the effect of change of brain material properties. Specifically pressure and strain values in the frontal and posterior fossa and occipital region of the brain are investigated for mid-high severity pulse.

The brain model is composed of several parts modeled as hexahedral elements and with different material properties. A parametric study of several material types of brain is conducted using MAthematical DYnamic MOdel (MADYMO). Initially only the finite element (FE) …

Study Of Multibody Dynamics Using Matlab, Kalyani Soman

Mechanical & Aerospace Engineering Theses & Dissertations

Research in computational dynamics has gained importance in the past few years because of the demand for analysis and simulation of various multi-body systems in the growing mechanical and aerospace industry. These multi-body systems are made of individual bodies that are interconnected via mechanical joints. Mathematically, these joints that connect the bodies can be described as constraint equations imposed upon the motions of the involved free bodies. This process will result in an equation of motion expressed in the form of a differential-algebraic equation. It is the main objective of this thesis to develop a solution algorithm that can take …

Process Study For The Design Of Small-Scale 2 Kelvin Refrigeration Systems, Peter N. Knudsen

Mechanical & Aerospace Engineering Theses & Dissertations

Helium refrigeration at temperatures below 4.5-Kelvin (K), but greater than 0.8-K typically employ a sub-atmospheric process utilizing a vacuum pumping system. These types of helium refrigerators are of keen interest to present and future particle physics programs utilizing super-conducting magnet or radio-frequency technology. As such, there is a need for small scale 2-K helium refrigeration systems (i.e., those that operated below the lambda temperature) in small laboratories and test facilities at this time. This study establishes the key process parameter choices of flow ratio, heat-exchanger size, and supply pressure, and how they influence the overall system performance for various process …

Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara

Civil & Environmental Engineering Theses & Dissertations

MPI/FORTRAN finite element analysis software based on Domain Decomposition (DD) formulas has been developed in this work. Efficient input data storage/data communication schemes, domain partitioning, fast symbolical and numerical sparse assembly, symmetrical/unsymmetrical sparse solver and robust symmetrical/unsymmetrical iterative solvers algorithms are all incorporated into the developed code. Parallel Precondition Conjugated Gradient (PCG) and Flexible Generalized Minimum Residual (FGMRES) are developed. Efficient computational techniques used in the developed code are explained. Numerical performance and the accuracy of the developed code are conducted on acoustic examples with medium to large grid sizes. The results obtained from ODU Wilbur cluster (under parallel processing …

Caffeine Model Identification For Vigilance Performance Prediction, Chun-Hui Huang

Mechanical & Aerospace Engineering Theses & Dissertations

The pharmacodynamics and pharmacokinetics of caffeine have been well characterized. In this study, a caffeine dynamic model is developed to describe its pharmacodynamic effects on vigilance performance. Validated biomathematical models developed to address both individual and group fatigue and alertness in a non-laboratory setting represent a tremendous commercial opportunity. First, a test data set with caffeine effects isolated from circadian and homeostatic effects is created. Then a modeling approach for input and output effects is developed and different model structures for the caffeine effects are considered. Observer/Kalman filter Identification (OKID) algorithm is proposed and developed to identify the caffeine model …

A New Method Of Synthesizing Black Birnessite Nanoparticles: From Brown To Black Birnessite With Nanostructures, Marcos A. Cheney, Pradip K. Bhowmik, Shizhi Qian, Sang W. Joo, Wensheng Hou, Joseph M. Okoh

Mechanical & Aerospace Engineering Faculty Publications

A new method for preparing black birnessite nanoparticles is introduced. The initial synthesis process resembles the classical McKenzie method of preparing brown birnessite except for slower cooling and closing the system from the ambient air. Subsequent process, including wet-aging at 7° C for 48 hours, overnight freezing, and lyophilization, is shown to convert the brown birnessite into black birnessite with complex nanomorphology with folded sheets and spirals. Characterization of the product is performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N(2) adsorption ( BET) techniques. Wet-aging and lyophilization times are …

The Effect Of Stirring On The Morphology Of Birnessite Nanoparticles, Marcos A. Cheney, Pradip K. Bhowmik, Shingo Moriuchi, Mario Villabos, Shizhi Qian, Sang W. Joo

Mechanical & Aerospace Engineering Faculty Publications

The effect of mechanical stirring on the morphology of hexagonal layer- structure birnessite nanoparticles produced from decomposition of KMnO₄ in dilute aqueous H₂SO₄ is investigated, with characterization by X- ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high- resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N₂ adsorption (BET). Mechanical stirring during an initial stage of synthesis is shown to produce black birnessite containing nanofibers, whereas granular particulates of brown birnessite are produced without stirring. This is the first reduction synthesis of black birnessite nanoparticles with dendritic morphology without any use …

Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya Deodhar, Sebastian Bawab, Aravind Hanasoge

Mechanical & Aerospace Engineering Faculty Publications

A dynamic model of the vehicle/guideway coupled with a controller is developed for the maglev demonstration system currently being developed at ODU, using the MAthematical DYnamic MOdeling software - MADYMO. The fundamental characteristics of the vehicle and guideway are obtained from detailed finite element analyses using MSC-NASTRAN. As a result, the vehicle is modeled in MADYMO as a 21- degree-of-freedom spring-mass-damper system. A three span concrete guideway is modeled using 3D solid Hex8 elements. The air gap is modeled as a penetration of the magnets into the guideway. Decentralized colocated PD controllers are used for controlling the penetration of each …

Dedication To Pierre Lallemand On The Occasion Of His Retirement, Dominque D'Humieres, Manfred Krafczyk, Li-Shi Luo, Robert Rubinstein

Mathematics & Statistics Faculty Publications

The fourth international conference for mesoscopic methods in engineering and science (http://www.icmmes. org), held in Munich, Germany, 16–20 July 2007, was closed with a celebration honouring Dr Pierre Lallemand on the occasion of his retirement from the Centre National de la Recherche Scientifique (CNRS) after more than 40 years of service.

An Integrated Simulation Design With Three-Dimensional Motions And A Hydraulic Stewart Simulator, Cheng Lin, Gene Hou, Yuzhong Shen, Hector Garcia

Engineering Technology Faculty Publications

This paper presents an integrated design process and tests of a Stewart simulator with a virtual visualization tool, which uses Virtools to create and generate three-dimensional motions. An inverse kinematic algorithm is written to convert each visualized motion to the displacements of six cylinders in a Stewart motion simulator. Information of the displacements is then transferred through the User Datagram Protocol (UDP) to a personal computer which has the LabVIEW software. An NI USB-6251 data acquisition device is applied to interact with the LabVIEW program and the Stewart hydraulic simulator. The approach presented in this paper to function an old …

Experimental Investigation Of Active Control Of Bluff Body Vortex Shedding, Ilteris Koc

Mechanical & Aerospace Engineering Theses & Dissertations

Mean and fluctuating forces acting on a body are strongly related to vortex shedding generated behind it. Therefore, it is possible to obtain substantial reductions of at least the unsteady forces if vortex shedding is controlled or its regularity is reduced. While conventional active flow control methods are mainly concerned with direct interaction with, and alteration of, the mean flow about a body, modern techniques involve altering existing flow instabilities using relatively small inputs to obtain large-scale changes of mean flows. Aerodynamic flow control may be intended to delay or suppress boundary layer separation through creation of a boundary layer …

Electroactive Polymers (Eap): Simulation Studies Of The Actuation Mechanisms In A Cantilever Cellulose Electroactive Paper, Fatim A. Mbaye

Electrical & Computer Engineering Theses & Dissertations

Electroactive polymers (EAPs) exhibit large strain in response to an external electric field and have attracted a great deal of attention in recent years for sensor and actuator applications. Favorable properties include soft actuation, ease and simplicity in manufacturing, being light-weight, low power consumption, and the ability to withstand harsh environments. However, this is an emerging material, and several aspects, including the fundamental mechanisms for piezoelectric deflections, remain unclear. This project studies the internal electromechanical factors that contribute to the voltage induced deflections of electro-active paper (EAPap). Experimental measurements of bias dependent deflections and water absorption as a function of …

Stochastic Optimization Formulations For Structure Design, Shivanandini Tanuku

Mechanical & Aerospace Engineering Theses & Dissertations

The production process and the operational environment of a product usually involve many unpredictable elements, such as the manufacturing tolerance, the service loads, the maintenance schedule, etc. Furthermore, the targeted functionality of a product can also be alternated or enhanced in its service life due to the technology advancement, new demands, or new regulation. It is thus a challenge to a designer to include these uncertainties in the early design stage of a product.

This thesis uses a simple three-bar truss problem as a vehicle to investigate the qualities of the optimal solutions resulted from various stochastic programming formulations. The …

Simulation And Thermo-Economic Analysis Of A Solar-Assisted Heat Pump System For Domestic Water Heating Application, Vaibhav D. Gagrani

Mechanical & Aerospace Engineering Theses & Dissertations

The present study examines the potential of solar-assisted heat pump (SAHP) system for domestic water heating application over conventional electrical water heating system. The focus of study is on developing a user-friendly and interactive software using Java platform with Microsoft Access being used for maintaining the database. The software developed is capable of predicting the thermal and economic performance of a SAHP system under varying conditions. The software allows the user to select the geographic location, specify condensing temperature, collector, and compressor parameters, and thermal load requirement. Location specific meteorological data, such as latitude, solar radiation, and ambient temperature, are …