Engineering Commons^™

Molecular Modeling In Anatoxin And Other Semirigid Agonists, Wen-Chung Shang

Theses

Conformational search and molecular mechanics calculations were combined to investigate the structural flexibility of isoquinolone, the anatoxin series, and the ferruginine series. Ring searching allow all rational conformations to be generated.

Isoquinolone shows conformational similarity to isoarecolone but is much less potent which suggests that the proximity of the methyl group beta to the carbonyl groups affects the bioactivity of isoquinolone. The very active agonist-anatoxin, without a similar conformation as isoarecolone, shared a similar electrostatic potential contour in the vicinity between the two atoms connected to the electro-positive nitrogen and hydrogen bonding site. These phenomena were not found in ferruginine …

Determination Of Aromatic Amines By Diazonium Salt, Hong-Hue Hsu

Theses

There are many analytical methods used in the identification of aniline by the production of various colors upon treatment with certain reagents. In this work a new inexpensive, easy and sensitive methods to quantitate aniline is developed. The change of absorbance is large enough to measure with a difference of only 1 ppm in the aniline concentration.

In this method, the reagent (2,4-dinitrodiazonium sulphate) which reacts with aniline produces a yellow color. Formation of this color (which absorbs at 486 nm) indicates the presence of aniline. The amount of aniline can be determined by measuring the absorbance at 486 nm. …

Agitation Requirements For Complete Dispersion Of Emulsions, Dun-Huang Tsai

Theses

An investigation on the minimum agitation speed required to achieve complete dispersion in liquid-liquid systems has been carried out. A model based on the momentum balance for a droplet and on Kolmogoroff's theory of isotropic turbulence was used for the prediction of the role of the most important variables on the minimum agitation speed. The equation so derived can be expressed in terms of a number of non- dimensional groups (such as Re, Ar, and Su). For geometrically similar systems the equation contains only one adjustable parameter ( to be determined experimentally) in the form of the proportionality constant correlating …

The Design, Manufacture And Mechanical Analysis Of An L4-5 Spinal Disc Prosthesis, Bohdan A. Siryi

Theses

The purpose of this research was to develop an intervertebral disc prosthesis which can provide the biomechanical properties of the natural disc. The prosthesis will be used to replace the symptomatic degenerated disc and thereby limit backpain and subsequent spinal disease.

Four cadaveric L4-5 motion segments were mechanically tested under axial compression and combined compression/torsion, generating compressive moduli and torsional stiffness values. Following, prosthetic discs were fabricated and mechanically tested, with the fabrication technique directed towards the optimization of mechanical properties in compression, torsion and bending.

Thirty silicon rubber and forty five polyurethane disc prostheses were fabricated. Silicon rubber, dacron …

Large Planar Maneuvers For Articulated Flexible Manipulators, Li-Farn Yang

Mechanical & Aerospace Engineering Theses & Dissertations

An articulated flexible manipulator carried on a translational cart is maneuvered by an active controller to perform certain position control tasks. The nonlinear dynamics of the articulated flexible manipulator are derived and a transformation matrix is formulated to localize the nonlinearities within the inertia matrix. Then a feedback linearization scheme is introduced to linearize the dynamic equations for controller design. Through a pole placement technique, a robust controller design is obtained by properly assigning a set of closed loop desired eigenvalues to meet performance requirements. Numerical simulations for the articulated flexible manipulators are given to demonstrate the feasibility and effectiveness …

The Effect Of Elastic Boundary Conditions On The Dynamic Response Of Rectangular Plates, Terry K. Brewer

Mechanical & Aerospace Engineering Theses & Dissertations

Natural frequencies and forced steady-state harmonic response for the vibration of uniform rectangular plates with edges elastically restrained against rotation and transverse translation are addressed. A single mode Rayleigh-Ritz solution is derived using functions that describe the normal modes of vibration of a beam whose ends are elastically restrained. The finite element solution is obtained for comparison. MACSYMA symbolic manipulation system is implemented as an aid to the mathematical rigor of the Ritz approach and NASTRAN finite element code is used to model the mechanical system. Comparisons are made to published results and the solutions of this study are found …

An Application Of Global Optimization Algorithm For Modal Parameter Identification, Chung-Men Chen

Mechanical & Aerospace Engineering Theses & Dissertations

Single-mode projection filters for modal parameter identification for flexible structures are introduced. An effective two-dimensional global optimization method using interval analysis is combined with the projection filters to facilitate identification for modal frequency and damping. A numerical simulation of a ten-mode structure is presented to illustrate the feasibility of the new method. The projection filters are practical for parallel processing implementation.

Development Of Load Carrying Thermoplastic Components For An Automotive Emergency Braking System, Joseph Gerard Sikora

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis describes a classical approach to plastic parts' design leading to the development of load carrying fiber reinforced thermoplastic components for use in an automotive emergency braking system. The control arms that are the focus of this study are designed to withstand the static loads characteristic of the loads experienced by an automotive emergency braking system. The present study is particularly significant as a case study because the design involves development of load carrying components for use in the harsh automotive environment.

Beginning with a fundamental concept for the control arms, basic design criteria, and a limited insight into …

Analysis And Design Sensitivity Computations Of Nonlinear Free And Forced Vibrations Of Stepped Beams, Yong Xiang Xue

Mechanical & Aerospace Engineering Theses & Dissertations

A finite element method is developed in this thesis for analyzing stepped beams under nonlinear free and forced vibrations. A new assumption is made to improve an existing finite element procedure for treating beams of nonuniform cross sections. The geometric nonlinearity results from the nonlinear, strain-displacement relation due to large deflection of a beam.

Based on an improved finite element procedure a computational method is then established for design sensitivity analyses of nonlinear eigenproblems pertaining to the free and forced nonlinear vibrations of beams. It is found that the equation for computing the design sensitivity of eigenvector is linear and …

Analysis And Optimal Design Of Pyramidal Truss Core Panels, Mark A. Wiseman

Mechanical & Aerospace Engineering Theses & Dissertations

The Pyramidal Truss Core Panel has been developed to save weight in applications normally devoted to solid plates. Present design formulas use classical beam theory with engineering assumptions made for moment of inertia and shear modulus determinations. Analysis with the SUPERSAP finite element code indicates that the present theory provides good prediction for the plate stresses but may be inadequate for the core stress and deflection determination. Two optimization routines are presented. The first procedure uses a batch file to execute separate programs with SUPERSAP used as the analysis code. The second combines a FORTRAN program used for analysis with …

Approaches To The Synthesis Of Dentin Bonding Agents Containing Vinyl And Carbamate Functional Groups, Steven W. Amato

Theses

The synthesis of four new monomers containing vinyl and carbamate functional groups was attempted. The desired products were N-m-methacryloxyphenyl-O-phenyl carbamate, N-p-methacryloxy-O-phenyl carbamate, m-N-phenylcarbamato-2-methacryloxyethoxy benzoate, and p-N-phenylcarbamato-2-methacryloxyethoxy benzoate. The carbamate functional group was derived by the Lewis Acid catalyzed reaction of meta-aminophenol, para-aminophenol, meta-aminobenzoic acid, and para-aminobenzoic acid with diphenyl carbonate. The vinyl function was derived, in the case of the aminophenols, by reaction with methacrylyl chloride, and in the case of the aminobenzoic acids, with 2-hydroxyethyl methacrylate.

Partial products only were prepared, these being the two carbamate functional phenols, the two carbamate functional benzoic acids, the two methacryloxy functional derivatives …

Geometric And Enthalpic Calculational Study Of Monosubstituted Cyclobutanes ; Attempted Synthesis Of 1,3-Diphenyl-2,2,4,4-Tetrafluorobicyclo [1.1.0] Butane, Jose Luis Reyesgavilan

Theses

The work undertaken in this thesis is in two parts. In the first, the structure and heat of formation of substituted cyclobutanes were studied via the computer program MMII using an IBM PCXT personal computer with a math co-processor chip. Structurally, a trend was seen to be followed in which bulkier substituents were pushed away from any steric interaction with the ring. This was accomplished by having the latter alter its puckering angle, C2C1C4 angle, HCX angle, and to a smaller extent, the bond lengths immediately adjacent to the substituted carbon atom. This results demonstrated that the ring was very …

Experimental Parametric Study Of A True Airspeed Sensor, Adel R. Ibrahim

Mechanical & Aerospace Engineering Theses & Dissertations

The results of an experimental parametric study of a true airspeed sensor are presented. The objective of this study was primarily to investigate experimentally the parameters that effect the frequency response of the true airspeed sensor. A secondary objective was to identify the sensor configuration which achieved the best performance. The model used to conduct these experiments basically consisted of swirl generator and vortex tube sections and pick-up signal system. A regression analysis was performed on the experimental results to obtain the effect of each parameter individually on the frequency response. The most significant parameters were selected by the regression …

Coupled Bending-Torsion Steady-State Response Of Pretwisted, Nonuniform Rotating Beams Using A Transfer-Matrix Method, Carl E. Gray Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

Using the Newtonian method, the equations of motion are developed for the coupled bending-torsion steady-state response of beams rotating at constant angular velocity in a fixed plane. The resulting equations are valid to first order strain-displacement relationships for a long beam with all other nonlinear terms retained. In addition, the equations are valid for beams with the mass centroidal axis offset (eccentric) from the elastic axis, nonuniform mass and section properties, and variable twist. The solution of these coupled, nonlinear, nonhomogeneous, differential equations is obtained by modifying a Hunter linear second-order transfer-matrix solution procedure to solve the nonlinear differential equations …

Production Of Blanking Circles And Dies - An Appropriate Method, V Bhandari

Tanzania Journal of Engineering and Technology (TJET)

A large important blanking die for production of multiwick stoves oil tanks was damaged beyond repair during normal maintenance. A replacement die could not be made available immediately. Initially an alternative blank production system based upon the adaptation of the inhouse and locally available tools was set up. Subsequently a temporary low cost and a permanent replacement blanking die was designed, developed and manufactured out of pad welding of mild steel plate. Recommendations have been drawn in light of the experiences gained in the deployment of these appropriate methods.

Towards The Development Of A Seed Minimum Tillage Planting, G Mutoizi

Tanzania Journal of Engineering and Technology (TJET)

Some advantages of minimum tillage compared to conventional tillage. systems are given. An evaluation of current minimum tillage planters is then made identifying two major problems namely the handling of trash. which detracts from making a continuous furrow of uniform depth, and unnecessary power Consumption When making this continuous furrow in spaced planting of seeds. Then the design, manufacture and development of a rig type of a seed injector for use in precision-drilling of a typical tropical geed is presented. It is to inject the Seed using rotary sleeve Valve in which is tractor drawn. Preliminary field testing of the …

Distributive Mixing Performance Of Rubber Internal Mixers, B Mutagahywa

Tanzania Journal of Engineering and Technology (TJET)

Results of experiments to study the distributive mixing performance of Internal mixers are reported in this paper. Distributive mixing was assessed by monitoring the uniformity of sulphur distribution throughout rubber mixes subjected to a range of rotor revolutions. The results indicate that distributive mixing in a well controlled Internal mixer is rapid and unlikely to be a source of mix variability.

Trends In Metal (Pb, Zn, Ni, As And Se) Concentrations In The New Jersey Air Environment, Geoffrey Ike Ejiofor

Theses

The trend and atmospheric concentrations of five trace elements (Pb, Zn, Ni, As and Se) were studied at Newark (urban site) and Ringwood (rural site), New Jersey, during January - September 1985, whilst the Hackensack Meadowlands, New Jersey were monitored during October 1985-March 1986. The analytical procedure involved collection of the airborne particulates on a glass fiber filter using a non-dichotomous high volume sampler. The samples were digested and analyzed using the atomic absorption spectrophotometer. It was ascertained that Newark and Meadowlands exhibited higher average concentrations of Zinc and Lead than Ringwood. It was concluded all the metals originated mostly …

Parametric Excitation Of An Axially Moving Band By Periodic Edge Loading, W-Z Ben Wu, C. D. Mote

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Simple torsion parametric resonance and combination torsion-bending parametric resonance can be excited in an axially moving band by an in-plane periodic edge loading that is normal to the longitudinal axis of the band. The model simulates band saws, belts, magnetic tapes and like systems under edge forces. Sum combination instabilities, in particular, permit the excitation of low frequency resonances by higher frequency edge forces. Simple bending, combination torsion-torsion, combination bending-bending and difference type parametric instabilities are not excited by periodic normal edge forces. The space of band parameters leading to parametric instability shrinks with increasing axial tension and with increasing …

Optimal Cure Cycle Design Of A Resin-Fiber Composite Laminate, Jeenson Sheen

Mechanical & Aerospace Engineering Theses & Dissertations

High performance polymeric composites have been experiencing increasing usage in the aerospace and automobile industries. Such materials are commonly composed of long or chopped fibers embedded in the thermosetting resin matrix. Changes in physical and chemical properties of such composite materials during the cure process are rather complex. Thus, it is not a trivial task to properly design a cure cycle (temperature and pressure profiles) for a cure process. The material should be cured uniformly and completely with the lowest void content; the temperature inside the laminate must not exceed some maximum value; and the cure process should be completed …

Physical And Mechanical Properties Of A New Type Of Polymer Concrete, Kyan Bin Khoo

Theses

A new type of Polymer concrete is an admixture of a special Latex, Portland cement and Sand. It has high bond strength, quick curing, durability and adequate strength. The Mechanical and Physical properties were investigated in this paper. Reinforcement with Glassfiber was done and its properties compared to those of control specimens. The heat generation in Polymer Concrete (PC) and its relationship with the properties of PC was also investigated.

A new type of Polymer concrete is an admixture of a special Latex, Portland cement and Sand. It has high bond strength, quick curing, durability and adequate strength. The Mechanical …

Eigenvalue And Eigenvector Design Sensitivity Analysis For Nonlinear Beam Vibrations, Jian-Zhong Yuan

Mechanical & Aerospace Engineering Theses & Dissertations

A beam with immovable ends under large amplitude oscillations is axially subjected to an amplitude-dependent stretching force which is induced by the geometrical nonlinearity. The design sensitivity analysis for such a beam is investigated in this study.

Two variational formulations based on different approximations of nonlinear stretching force are studied firstly. The analytical equations of design sensitivity analysis for these nonlinear eigenproblems are then derived. Finally, a computational scheme using finite element method is developed to calculate the design sensitivity derivatives of the eigenvalue and eigenvector numerically. Numerical examples associated with the nonlinear eigenvalue and eigenvector analysis, as well as …

Vibration Coupling In Continuous Belt And Band Systems, C. D. Mote, W-Z Ben Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Small transverse oscillation of an endless band supported by wheels couples the response of the free spans of the band to oscillation of the wheels. The coupling arises from the finite curvature of the free spans of the band when its bending stiffness is finite. Significant modeling error can occur if a single span of the band is modeled as a simply supported, axially moving beam. The coupling provides an opportunity to dissipate vibration energy. Experiments and finite element analyses support the coupling discussion presented. © 1985 Academic Press Inc.

An Electro Hydrodynamic Study Of The Negative Corona Electric Wind, Henry Thadei Kadete

Tanzania Journal of Engineering and Technology (TJET)

The velocity of corona generated electric wind is measured. From the velocity profile mass movement and electrokinetic conversion efficiencies are deduced. High speed schlieren photographs illustrate the form of the velocity distribution function as well as its high degree of turbulence.

The Quantitative Analysis Of Airborne Particulates By X-Ray Flourescence, George C. Asteriou

Theses

Airborne particulate matter from the New Jersey State area collected on Quartz Microfiber filters was analyzed by X-Ray Fluorescence spectroscopy. The quantitative analysis of the samples against N. B. S. standards produced results which were compared with Atomic Absorption analysis

The results from the two methods were correlated by the introduction of empirical factors for each element.

However, a larger number of analyzed standards of varied composition, along with the creation of a spectral library, can minimize the need for empirical factors and yield accu¬rate results.

Structural Self-Shadowing And Its Effects On The Thermal-Structural Behavior Of Orbiting Trusses, Jack Mahaney

Mechanical & Aerospace Engineering Theses & Dissertations

The determination of structural shadowing is described. The computation of environmental heat loads for slender structural members in earth orbit is described, and two methods for finite element thermal analysis are described . The effects of self-shadowing on the thermal structural behavior of single truss members and two different trusses are presented. In each case the shadowing produces a noticeable effect on the temperature distributions on truss members, and on the deformations of the trusses.

Analysis And Optimal Design Of Wind Tunnel Balances, Sung-Ling Twu

Mechanical & Aerospace Engineering Theses & Dissertations

The problem of finding the optimal cross-sectional shape of the elastic cage in wind tunnel balance is formulated and solved numerically. A mathematical model to implement the boundary condition associated with the elastic rigid connection into the finite element method is discussed. Numerical results show that the rigid connection at the end of the elastic cage has significant effect on the stress distribution.

The finite dimensional approach for a three dimensional design sensitivity analysis is derived. Using both the free and rigid boundary conditions, numerical examples are performed and comparisons of the accuracy of design sensitivity analysis between the proposed …

Microcomputer Based Digital Image Processing System Developed To Count And Size Laser-Generated Small Particle Images, K. D. Ahlers, D. R. Alexander

Department of Mechanical and Materials Engineering: Faculty Publications

A microcomputer-based digital image processing system has been developed to count and size laser-generated small particle images. Processing rates of 5 to 600 frames per minute were achieved by utilizing a real-time digital image processor. Particles from 7 to 700 µm in the plane of focus were counted and sized. A major emphasis in this work was to determine the basic problems and limitations involved with using a digital image processing scheme to accurately size particles. Areas that were investigated include the effect of the threshold level on measured particle size, particle boundary diffraction gray-level gradients, and geometric nonlinearities introduced …

Negative Corona Current Characteristics Of An Electric Wind System, Aviti Kadete

Tanzania Journal of Engineering and Technology (TJET)

The corona current characteristics of an electric wind system are investigated. First a brief summary of the negative point to plate corona mechanism and characteristics are presented. Then empirical equations for corona currents of an electric wind system are derived. Current waveform characteristics are also discussed. The effects of placing parallel rods in between a point-plate electrode gap to the corona currents are highlighted.

The Eccentric Disc Pitter Planter-A Soil Conservation Tillage Tool For Mechanized Farming., J Dumelow

Tanzania Journal of Engineering and Technology (TJET)

A planting technique which could enhance agricultural production is presented. The Edip planting technique which is discussed has low capital and operating costs. It also has reasonable and reliable yields as well as providing effective moisture and soil conservation.