Engineering Commons^™

Experimental Investigations On The Behaviour Of Wood In Transverse Compression, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

Experimental investigations were done to study the behaviour of wood in transverse compress ion. Three key variables were incorporated in the experiments to study their influence on the •nriables were the orthotropic ratio of the behav iour. These material, the geometry of loading and that of the specimen . Deformation measurements were made at selected locations on test specimens by means of strain—gage based clip gages. Results from the experimental measurements were compared to previous deformation predictions made by a finite element analysis (9) . There is a very good agreement between measured values and those obtained trom the finite …

Density Measurement For Corrosive Solutions At Elevated Temperatures, Kimweri, H

Tanzania Journal of Engineering and Technology (TJET)

In this work, apparatus for measuring densities of corrosive solutions at high temperatures was developed and used. Densities of dilute aqueous sulphuric acid solutions, containing different amounts of zinc and iron salts were measured at temperatures up to 185°C. In view of the good agreement between consecutive measurements for each solution and the density of water obtained by using this apparatus with that given in literature, for all experiments, the apparatus is recommended to be used for measuring densities of corrosive solutions at high temperatures.

Electrical Equivalent Method For The Calculation Of Vibrations In Transformers, D Chambega

Tanzania Journal of Engineering and Technology (TJET)

Noiselevel calculations may be done using an electrical equivalent method. So far a single mass and a double mass vibrating system may easily be represented by equivalent electrical circuits which are in turn useful for analysis. Multimass vibrating systems like transformers do not have straightforward methods which can enable analysis of noiselevels. This paper attempts to develop such a method by extending the method applicable to a double mass vibrating system. Then the validity of the method is tested using a transforme

Factors Affecting Capacity Utilization In Industries: Hierarchical Analysis, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper provides a hierarchical analysis of the factors affecting capacity utilization in Tanzanian industries. Several factors were identified and sent to randomly selected industries in Tanzania for ranking. The collected data was summarized and analyzed. The analysis made use of a known procedure, the 'Analytical Hierarchy Process' (AHP). The final results shows a ranking of the factors, on various hierarchical levels as to their percentage contribution in lowering the capacity utilization.

Three Dimensional Visualisation Of Tmj Anatomy Using Mri Techniques, Mythreyi T. Krishnaswamy

Theses

The best assessment of temporomandibular joint (TMJ) can only be done by the scanning the jaw and getting an image without invivo analysis which causes patient discomfort. There have been innumerable efforts to get the best view using CT techniques for three dimensional visualisation. But very few have done work using MRI techniques.

The TMJ is an integral part of the jaw and helps in mastication and biting. Since the joint is a hinge sliding articulation any dislocation causes immense pain and discomfort.

To get a better assessment of the TMJ, MRI techniques have been used for data acquisition. The …

Design, Operation And Maintenance Considerations Of Iiorizontal Flow Roughing Filters Preceding Slow Sand Filters, T Mbwette,

Tanzania Journal of Engineering and Technology (TJET)

The paper mentions some of the reported uses of Horizontal Flow Roughing Filters (IIRF) in drinking water treatment plants in Europe before briefly reviewing research activities carried out in the use of IIRF prior to Slow Sand Filters. Design, operation and maintenance aspects Of HRF are reviewed on the basis of the laboratory and field tests carried out in Tanzania and Switzerland, respectively in addition to experience gained in operation of a number of plants already built to date. Design aspects are introduced from the point of view Of its philosophy and optimization strategies before design guidelines are given. Important …

The Stability And Sate Dimensioning Of Circular Masonry Arches, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

An analysis of masonry arches where collapse is assumed to occur by the hinging of voussoirs upon each other is made. The behaviour of the arch material is assumed to be such that the plastic theory is valid. Certain aspects related to the properties So far the approach by of the line of thrust are clarif led. writers has been based on the conventional view that the 1 ine of It is shown that pressure is tangential to the line of thrust. this is not the case in general. Definitions are given on what is meant by "line of thrust" …

Nitrogen Oxides Rbsorption Into Sodium Hydroxide Solution In A Packed Column Column: Effect Of Naoh Concentration, J Katima

Tanzania Journal of Engineering and Technology (TJET)

Experiments have been conducted to evaluate the ettect of sodium hydroxide (NaOH) concentration upon the absorption rate of nitrogen oxides (NO ) and packed column performance. The absorption process using was carried out at atmospheric pressure and 29B K, concentrations between zero and w/ w, NO/ NO ratio of 0.5 and NO concentrations between 150 and 10000 ppm in an air mixture. The performance of the calumn was enhanced by the presence of hydroxyl ions ( 0B - ) relative to the absorption into water, however, The absorption it was found to be independent of NaOH concentration. rate of NO …

Carrying Capacity And Cracking Resistance At The Of Halving Joints In Reinforced Concrete Beams, S Mpinzire;

Tanzania Journal of Engineering and Technology (TJET)

Results are presented from tests on 3 beams having discont inuous support zones. All Of them had web and diagonal shear reinforcement. TWO out Of the three represented beams, their test results have been analysed in a paper designated part I which appeared in the Uhandisi Journal , Vol. I December 1989. They have been presented in this paper for compar ison purposes. The third beam has been made to invest i gate the effect of anchoring diagonal shear reinforcement by spot Welding method. The third beam was tested With two concentrated loads in the span. In all beams several …

A Finite Element Analysis Of Wood In Transverse Compression, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

A two dimensional finite element analysis is utilized to predict the stress and strain distributions for wood in transverse compression. Important key var iables are incorporated into the ana lysis to define their influence on the stress and strain distributions. These variables are geometry of loading, geometry of specimen and the orthotropic ratio of the material. Based on the finite element analysis results, relationships are arising stress from developed relat ing maximum stress concentrations to the above three variables. possible appl ications of the results from this study relate to the development of more efficient design of connections such as …

Comparative Study Of Inlet Manifold Tuning To Enhance Supercharge, Mtui L

Tanzania Journal of Engineering and Technology (TJET)

Computer model ing and experimental results on a single cylinder, four-stroke cycle engine for best air flow characteristic is The modeling analysis is based on hornet ropie fluid di scussed . The model n g resul s is flow w it. h constant: specific heats. included to val idat.e the s imulation program against experimental results with widely vary ing manifold lengths and engine speeds. ExperimenLal results are obtained by measuring air f low rates Lo the inlet valve during steady g Late speed Of Lhe engine. Manifold tuned lengths are Obtained for a range Of speeds by exper and …

Effects Of Feed Solids Concentration On Dual Functionality Of A Hydrocyclone., Zanzu M

Tanzania Journal of Engineering and Technology (TJET)

The dual functionality, i.e. thickening and classification of a 50.8mm diameter hydrocyclone has been investigated. A metallurgical slime consisting of a 50% mixture of quartz and petroleum coke was used in the tests. It was found that in order to achieve both thickening and classification at the same time, the pressure drop across the hydrocyclone, the underflow diameter and the feed solids content have to be subtly controlled.

A Color Petri Net Simulation Tool, Sanjaykumar V. Desai

Theses

A user friendly, modular and highly interactive graphical tool for drawing, editing and simulating color Petri nets is developed. The tool is designed to model concurrent and interlocked systems, such as flexible manufacturing systems, communication protocols and computer systems. A Color Petri Net(CPN) has a more concise graphical system representation than a standard Petri net, because net entities in CPN carry information. The CPNS(Color Petri Net Simulation) tool simulates a net having conflicts, reveals deadlocks, and creates a log file with the state history of the system yielding performance measures.

Comparison Of Timing Jitter In External And Monolithic Cavity Mode-Locked Semiconductor Lasers, Dennis J. Derickson, P. A. Morton, J. E. Bowers, R. L. Thornton

Electrical Engineering

A comprehensive timing jitter comparison is made for mode-locked semiconductor lasers using active, passive, and hybrid mode-locking techniques in both external and monolithic cavity configurations. Active mode locking gives the lowest residual rms timing jitter of 65 fs (150 Hz-50 MHz), followed by the hybrid and passive mode-locking techniques. It is found that monolithic cavity devices with all active waveguides have higher timing jitter levels than the comparable external cavity case.

Limits Of Limit Equilibrium And Finite Element Techniques Applied To Cracked Debris Dams On Collapsing Foundations, Stanley Soliday Jr.

Dissertations and Theses

Limits of slope stability, limit equilibrium methods, and of the finite element code FEADAM are reached in the application of these methods to the problem of cracked dams constructed on collapsing soils.

Utilizing a generic dam, various classic slope stability approaches are tested as possible dam slope failure mechanisms. Slope stability methods are rejected as a way to accurately define and quantify the collapse problem. As a result of this work a block rotation mode of collapse is postulated. Then the finite element method (FEM) is used to try to define and quantify the collapse problem. The FEM is applied …

Ignoring Interprocessor Communication During Scheduling, Chintamani M. Patwardhan

Dissertations and Theses

The goal of parallel processing is to achieve high speed computing by partitioning a program into concurrent parts, assigning them in an efficient way to the available processors, scheduling the program and then executing the concurrent parts simultaneously. In the past researchers have combined the allocation of tasks in a program and scheduling of those tasks into one operation. We define scheduling as a process of efficiently assigning priorities to the already allocated tasks in a program. Assignment of priorities is important in cases when more than one task at a processor is ready for execution. Most heuristics for scheduling …

A Multiple Coupled Microstrip Transmission Line Model For High-Speed Vlsi Interconnect Simulation, Lawrence Stevan Uzelac

Dissertations and Theses

A model is presented which incorporates the advantages of a mixed mode simulation to characterize transmission line behavior in multiple coupled Transmission line systems. The model is intended for use by digital circuit designers who wish to be able to obtain accurate transmission line behavior for complex digital systems for which continuous time simulation tools such as SPICE would be time prohibitive.

The model uses a transverse electromagnetic wave approximation to obtain solutions to the basic transmission line equations. A modal analysis technique is used to solve for the attenuation and propagation constants for the transmission lines. Modal analysis done …

An Investigation Of Digital Microprocessor Algorithms In Active Suspension Systems, Toby L. Mcclellan

Graduate Research Papers

The need for knowledge and understanding of these systems at the technician level will increase dramatically as other manufacturers develop production systems in the 90's. Current technical literature on the subject of active and semi-active suspension systems does not well explain a major aspect of these systems, the origin and nature of the control algorithms used. A review of 30 articles and technical papers, and a title search of over 300 others discovered only 2 vague presentations of the actual control logic used in such systems. Furthermore, the control information that was printed was presented in terms of Laplace transforms …

Method For Gaseous Component Indentification With #3 Polymeric Film, Edward S. Kolesar Jr.

AFIT Patents

A sensor having an interdigitated gate electrode field effect transistor (IGEFET) coupled to an electron beam evaporated copper phthalocyanine thin film is used to selectively detect parts-per-billion concentration levels of atmosphere contaminants such as nitrogen dioxide (NO₂) and diisopropyl methylphosphonate (DIMP). The sensor is excited with a voltage pulse, and its time- and frequency-domain response are examined. The envelopes of the magnitude of the normalized difference frequency spectrums reveal features which unambiguously distinguish the NO₂ and DIMP exposures.

Migrating A C-Based Cad Tool To An Object-Oriented Database/C++ Environment: Conversion Costs And Performance Analysis, Mark A. Roth, Timothy M. Jacobs

AFIT Documents

his paper examines the potential of object-oriented databases to support complex design applications. To do this we migrated the Magic very large scale integrated (VLSI) circuit design tool written in the C language to a new environment in which Magic's existing file management code is replaced with a C++ language interface to the commercial object-oriented database management system (OODBMS) product Object Store. In our initial implementation we found the performance of this tool as implemented on the OODBMS to be marginally faster than the tool as currently implemented with a flat file system in several critical areas. Increased functionality, including …

Spectral And Spatial Quantum Efficiency Of Algaas/Gaas And Ingaas/Inp Pin Photodiodes, Steven Alan Tabor

Dissertations and Theses

This thesis reports a novel system capable of testing both the spectral responsivity and the spatial quantum efficiency uniformity of heterostructure photodiodes using optical fiber coupled radiation. Testing was performed to confirm device specifications. This study undertakes to quantify the spectral bandwidth of an AlGaAs I GaAs double heterostructure photodiode and two InGaAs I InP double heterostructure PIN photodiodes at D.C., through the use of spatial scanning. The spatial scanning was done using lasers at 670 nm, 780 nm, 848 nm, 1300 nm, and 1550 nm, coupled through singlemode optical fiber. The AlGaAs I GaAs material system covers the 600 …

Unsteady Flow In Vertical, Converging Tubes, Hamid Johari, William W. Durgin

Office of the Provost Scholarship

The discharge of liquids from vertical tubes with various contraction geometries was studied via the unsteady Bernoulli equation. The temporal variations of the exit velocity and fluid level in the tube were found from the numerical integration of nonlinear differential equations. Sudden, quadratic, and exponential contraction geometries were considered. For inlet to exit area ratios greater than two, the flow initially accelerates to a maximum speed and then it decelerates for the geometries studied. The exponential contraction has the shortest discharge time. The solutions also reveal that the largest possible velocity and the shortest discharge time are achieved in a …

Acuta Enews December 1991, Vol. 20, No. 12

ACUTA Newsletters

In This Issue

10-XXX gives occasion for fraud

President's Message

YaleNET, a variety of services

Think ahead to prevent fraud

MOREnet links 12 campuses

Positions available

Evaluation Of Torsional Provisions In Seismic Codes, Anil K. Chopra, Rakesh K. Goel

Civil and Environmental Engineering

The effects of plan asymmetry on the earthquake response of code-designed, one-story systems are identified with the objective of evaluating how well these effects are represented by torsional provisions in building codes. The earthquake-induced deformations and ductility demands on resisting elements of asymmetric-plan systems, designed according to several different codes, are compared with their values if the system plan were symmetric. The presented results demonstrate that the design eccentricity in building codes should be modified in order to achieve the desirable goal of similar ductility demands on asymmetric-plan and symmetric-plan systems. The design eccentricity should be defined differently for elastic …

9th Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 9th Conference on Senior Engineering Design Projects was held on December 10, 1991 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

Composite Damage Assessment Employing An Optical Neural Network Processor And An Embedded Fiberoptic Sensor Array, Barry G. Grossman, Xing Gao, Michael H. Thursby

Electrical Engineering and Computer Science Faculty Publications

This paper discusses a novel approach for composite damage assessment with potential for DoD, NASA, and commercial applications. We have analyzed and modeled a two dimensional composite damage assessment system for real-time monitoring and determination of damage location in a composite structure. The system combines two techniques: a fiberoptic strain sensor array and an optical neural network processor. A two dimensional fiberoptic sensor array embedded in the composite structure during the manufacturing process can be used to detect changes in the mechanical strain distribution caused by subsequent damage to the structure. The optical processor, a pre-trained Kohonen neural network, has …

Evolution And Impact Of Changes Of Technological Development In Some Of The French Manufacturing Organizations, T S Nagabhushana

IIMB Management Review

No abstract provided.

Computerized Aircraft Accident Investigation: Federal Aviation Administration Aviation Safety Inspectors' Perceptions, David S. Ryan

Master's Theses - Daytona Beach

The purpose of this study was to solicit the perceptions of Federal Aviation Administration (FAA) Aviation Safety Inspectors (ASIs) on the use of a personal computer in the aircraft accident investigation process. A descriptive study survey questionnaire was used to collect the data for the study, which was sent to 150 FAA ASIs. The data collected supported the hypothesis that aircraft accident investigators think the use of a computer will help them with accident report form completion, managing the accident data collected, and in determining the factors contributing to an accident. Furthermore, the data supported the hypothesis that the use …

The Calendar - December 1991, Nova University

The Calendar

No abstract provided.

Neural Control Of Smart Electromagnetic Structures, Michael Thursby, Kisuck Yoo, Barry G. Grossman

Electrical Engineering and Computer Science Faculty Publications

Artificial neural networks (ANNs) and their ability to model and control dynamical systems for smart structures, including sensors, actuators, and plants, are directly applicable to the smart electromagnetic structures (SEMS) concept. The application of neural networks to the area of controls is being reported frequently. The ability of a structure to adapt to impinging electromagnetic (EM) energy will allow the structure to change its reflection characteristics and thus to change its radar signature. By embedding a control element in the structure of a single microstrip patch element, its electrical characteristics can be changed. If such an element can be controlled …