Engineering Commons^™

Measurement Of Dust Resistivity And The Effect Of Filter Operating Parameters On Its Value, Allan Issangya

Tanzania Journal of Engineering and Technology (TJET)

Methods sed to measure the electrical resistivity of a dust layer and to determine the influence of various parameters. Dust layer thickness and applied voltage were found to have no influence. Resistivity depends on particle size, packing density, temperature, and air relative humidity. Glass beads and limestone powders of different mean particle sizes were used. Temperature was varied from 20–100 °C and air moisture ranged from dry to near saturation. The findings may help in understanding electrically enhanced fabric filters, whose performance is influenced by the resistivity of the collected dust layer.

Optimal Capacity Allocation Truck Industry In Tanzania:A Case Of National Transport Corporations(Ntc), R Mgaya

Tanzania Journal of Engineering and Technology (TJET)

This paper tries to examine truck transportation service in Tanzania, particularly, in National Transport Corporation’s subsidiary companies - Regional Transport Companies. It provides an analysis based on operations research approach on resource allocation, specifically, truck allocation, with an aim of trying to minimize running costs and hence improve profits. It is established that there had been higher running costs and hence decline of profits in some Regional Transport Companies due to misallocation of capacity. However, this problem had been compounded by some other factors as discussed in the paper. It is recommended that these Regional Transport Companies and other transport …

Dual Versus Single Spark Plug: A Critique, I Mshoro

Tanzania Journal of Engineering and Technology (TJET)

Dual spark plugs are occasionally employed on certain modern Spark lg- nited (S') engines, viz lean burn engines. Their benefit has generally been noticed in the operating conditions whenfuel-air mixture is very lean, or when a larger proportion of EGR has been employed, or during the part load conditions and so on. An extensive literature survey has indi- cared an interesting spectrum of reasons for gains due to the dual spark plug. A consistent explanation is found to be missing which can describe the behaviour of the engines with single versus dual spark plugs There are quite "few researchers who …

Suitability Of The Present Strategic Information Technology Planning (Sitp) Methodologies To The Developing Countries, A Victor

Tanzania Journal of Engineering and Technology (TJET)

The needfor strategy formulation, or in general terms strategic planning, for IT is considered as one of the most important aspects of IT manage- ment. To this end, there are a number of IT strategy formulation method- ologies world-wide. These methodologies were developed over a span of time, starting from mid 1960's when IT use started to become a serious issue in the developed countries, and continued with the trends in IT de- velopment and use, as was applicable in those countries. Morc recent of the methodologies were developed through improvements on earlier ones, and based on the new challenges …

The Response Of Dispersion-Strengthened Copper Alloys To High Fluence Neutron Irradiation At 415⁰C, Danny J. Edwards, Joseph William Newkirk, Frank A. Garner, Margaret L. Hamilton, A. Nadkarni, P. Samal

Materials Science and Engineering Faculty Research & Creative Works

Various oxide-dispersion-strengthened copper alloys have been irradiated to 150 dpa at 415°C in the Fast Flux Test Facility (FFTF). The Al₂O₃-strengthened GlidCop™ alloys, followed closely by a HfO₂-strengthened alloy, displayed the best swelling resistance, electrical conductivity, and tensile properties. The conductivity of the HfO₂-strengthened alloy reached a plateau at the higher levels of irradiation, instead of exhibiting the steady decrease in conductivity observed in the other alloys. A high initial oxygen content resulted in significantly higher swelling for a series of castable oxide-dispersion-strengthened alloys, while a Cr₂O₃ -strengthened alloys …

Inversion Of Light Scattering Measurements For Particle Size And Optical Constants: Theoretical Study, Matthew R. Jones, Bill P. Curry, M. Quinn Brewster, Keng H. Leong

Faculty Publications

We invert the Fredholm equation representing the light scattered by a single spherical particle or a distribution of spherical particles to obtain the particle size distribution function and refractive index. We obtain the solution by expanding the distribution function as a linear combination of a set of orthonormal basis functions. The set of orthonormal basis functions is composed of Schmidt-Hilbert eigenfunctions and a set of supplemental basis functions, which have been orthogonalized with respect to the Schmidt-Hilbert eigenfunctions by using the Gram-Schmidt orthogonalization procedure. We use the orthogonality properties of the basis functions and of the eigenvectors of the kernel …

Inversion Of Light Scattering Measurements For Particle Size And Optical Constants: Experimental Study, Matthew R. Jones, Keng H. Leong, M. Quinn Brewster, Bill P. Curry

Faculty Publications

Measurements of the light scattered by a sample contain information regarding the physical properties of the sample. Laser light-scattering measurements can be made unobtrusively in environments that are inaccessible to other types of measurements, so laser light-scattering techniques have become an important tool in aerosol research. The primary difficulty associated with using light-scattering techniques to determine aerosol particle properties is inverting the measurements or extracting the desired information from the measurements. In this study we use a 15-channel polar nephelometer to measure the light-scattering patterns of monodisperse polystyrene spheres. The light-scattering measurements are inverted, and the particle size distribution function …

Comparison Of The Environmental Effects Of Aerobic And Anaerobic Composting Technologies, Samuel A. Vigil, George Tchobanoglous

Civil and Environmental Engineering

The biological conversion of yard wastes and municipal solid waste by aerobic composting is an established technology. Anaerobic conversion of these wastes is less practiced but is being widely advocated for the next generation of bioconversion systems. Although the operational characteristics of both types of systems is well known, there is a lack of quantifiable data in the literature on the environmental effects of these technologies. It is widely assumed that they are environmentally benign, especially as compared to other processing and conversion technologies such as incineration or mechanical processing. The process microbiology, design, and operational characteristics of aerobic and …

Evaluating Strength & Energy Requirements For Workers Picking Vegetables, R. A. Cavaletto, J. Miles, J. Meyers, J. Mehlschau

BioResource and Agricultural Engineering

The paper discusses the need to obtain field data to evaluate the strength and energy requirements for workers picking a variety of vegetables. This information is central to the evaluation of hazards related to repetitive motion, excessive stress, and fatigue. Results can be used to select activities which should be targeted for future engineering design projects. Preliminary data from a commercial broccoli harvesting operation is included.

Grassland Basin Irrigation And Drainage Study, Stuart W. Styles, Dennis Westcot, Charles M. Burt, Ross Steensen

BioResource and Agricultural Engineering

This paper summarizes a project that analyzed the district irrigation efficiency for six subareas of the Grassland Basin roughly representing 80,000 acres on the west side of the San Joaquin Valley near Firebaugh, California. The objectives of this project were to: • Determine the district irrigation efficiency for the six subareas. • Update district drainage policies and water reuse. • Update the geographical information system (GIS). • Perform a pre-plant irrigation efficiency analysis. • Establish a relationship between the drainage volumes and the district irrigation efficiency. • Determine the maximum district irrigation efficiency attainable. • Determine the impact of optimizing …

High Shear Mixing Reactor For Glycerolysis, Hossein Noureddini

Papers in Biomaterials

lnrcreased ervironmental awareness and depletion of resources are driving industry to develop aiternative fuels from renewable resources that are environmentally more acceptable. Esters of fatty acids (biodiesel), derived from the transesterification of vegetable oils, have properties similar to cornponents of petroleum based diesel fuel. Cost has been a major factor in slowing down the commercialization of biodiesel. In order to improve the economy of this process two factors were investigated in this study: 1) use of beef tallow as raw material and 2) by-product utilization.

Glycerol is the by-product of the esterification process. In this work the feasibility of the …

Impression Creep Behavior In Weldments, S.H. Wang

Journal of Marine Science and Technology–Taiwan

At high temperature application, the failures of dissimilar metal weldments associated with the relevant degradation processes, which include chemical diffusion, oxide notching, precipitation, softening of the heat affected zone (HAZ), and creep type voids leading to cracking. This reveals that a creep in a gradient related to the microstructural degradation exists. The impression creep test was applied to monitor the effects of microstructural gradients on the localized high temperature creep properties in an autogeneous GTA aluminum weldment, and an austenitic stainless steel to ferritic steel dissimilar metal weldment respectively. To simplify the complexity of microstructural gradients, multipass weldments in A36 …

A Study Of Chloride Diffusion Properties Of Concrete At Early Age, W.D. Yeih, R. Huang, J.J. Chang

Journal of Marine Science and Technology–Taiwan

Existence of chloride ions in concrete may accelerate reinforcement corrosion. Chloride ions can penetrate into the concrete by the diffusion process even if no major cracks exist. It is well known that properties of concrete will change with time since the hydration reaction continues for a long time, which implies that the diffusion coefficient of concrete is a time-dependent function. In this research, the diffusion behavior is focused on early-age mortar and concrete. It is shown that the diffusion coefficient changes dramatically at early age; and the control of interface property is significantly important to chloride diffusion. The effect by …

The Use Of Ac And Dc Methods For Corrosion Monitoring Of Reinforced Concrete Members In Marine Environment, R. Huang, W.D. Yeih, J.J. Chang, C.C. Yang

Journal of Marine Science and Technology–Taiwan

Reinforced concrete is the most common engineering material for civil structures. The durability of the concrete structures depends mainly on the corrosion of steel reinforcement. In general, concrete produces an alkaline environment for steel which passivates it, so preventing corrosion. Provided this passivity is maintained, no problem should arise with steel reinforcement. However, in certain environment, chloride ions can locally destroy very protective passive film of reinforcement even though concrete is still alkaline. This paper presents the corrosion results of reinforcing steel in concrete members in marine environment using the AC impedance technique and DC method.

Viscoelastic Buckling And Postbuckling Of Circular Cylindrical Laminated Shells In Hygrothermal Environment, N.N. Huang

Journal of Marine Science and Technology–Taiwan

The viscoelastic buckling and postbuckling behaviors of fiber-reinforced plastic (FRP) circular cylindrical shells, operating in the hygrothermal environment, subjected to uniform external pressure are investigated in this study. The FRP is assumed to be a hy grothermorheologically simple material (HTSM). The analysis is conducted within the framework of the quasielastic approach. The finite element method is employed to examine both buckling and postbuckling behaviors for shells having arbitrary layups. The arc-length algorithm is incorporated into the finite element formulations to trace the postlimit equilibrium path. The structural responses of Glass/Epoxy shells are reported.

Analysis Of Three-Dimensional Pile Groups, M.T. Liang, Y. Liu

Journal of Marine Science and Technology–Taiwan

A numerical technique is presented in the analysis for loading behavior of general three-dimensional pile groups. The striking characteristics of the pile-group model may include raked pile, different pile sizes, non-uniform pile sections, soil inhomogeneit y, soil nonlinearity, and pile-soil-pile interaction. A typical six-pile group is analyzed and the results are compared with that obtained by four other computer programs that are based on different approaches. The computed solutions are shown to have reasonally good agreement with the measured values.

Vibration Analysis Of Timoshenko Beams Traversed By Moving Loads, Yih-Hwang Lin

Journal of Marine Science and Technology–Taiwan

The purpose of this research is to apply the finite element method for dynamic analysis of Timoshenko beams traversed by moving loads. When an elastic structure is subjected to moving loads, the induced displacements and stresses are much higher than those of static loading conditions. Due to the prevalence of high speed machinery and the use of light and flexible structures to reduce the material cost, structural weight, and space requirement, dynamic analysis of such systems becomes crucial to ensure structural safety and required accuracy. In this study, the shear effect and rotary inertia were included for the analysis of …

Analysis Of Homogeneous Slurry Pipe Flow, R. C. Chen

Journal of Marine Science and Technology–Taiwan

An analysis is performed for the solid-liquid slurry pipe flow in the homogeneous flow regime. The transport and concentration equations are constructed based on two-liquid postulation and modified Rouse-Schmidt diffusion relation. By considering the interphase interaction effects, a general k-e model is applied to describe the turbulent kinetic energy production and dissipation. Coupling with the physically-defined parameters, this model is able to obtain the axial velocities of the solid and liquid phases, the solid concentration distribution and the liquid turbulent kinetic energy and dissipation rate. Excellent agreement between the calculated axial velocity profiles and the experimental data obtained by Chen …

Demonstration Of A Novel 3-D Autostereoscopic Display, M. W. Jones, Gregory P. Nordin, S. T. Kowel, J. H. Kulick, R. G. Lindquist, P. J. Nasiatka

Faculty Publications

We report what we believe is the first static implementation of the partial-pixel architecture, which provides a conceptual framework for the construction of real-time three-dimensional displays that are functionally equivalent to holographic stereograms (i.e., the simultaneous display of a series of stereoscopic images). The device is physically realized as a set of amplitude diffraction gratings on a chrome mask that was fabricated by standard photolithographic techniques. The intended three-dimensional object encoded in the display was strikingly visible on readout with an incoherent illumination source.

The Design, Realization And Testing Of The Ilu Of The Ccm2 Using Fpga Technology, David W. Foote

Dissertations and Theses

Most existing computers today are built upon a subset of the arithmetic system which is based upon the foundation of set theory. All formal systems can be expressed in terms of arithmetic and logic on current arithmetic computers through an appropriate model, then work with the model using software manipulation. However, severe speed degradation is the price one must pay for using a software-based approach, making several high-level formal systems impractical.

To improve the speed at which computers can implement these high-level systems, one must either design special hardware, implementing specific operations much like math and image processing coprocessors, or …

A Preliminary Model For Lot Sizing In Semiconductor Manufacturing, Tali F. Carmon, Steven Nahmias

Industrial and Manufacturing Engineering

No abstract provided.

Hydraulic Conditions Required To Move Unanchored Residue Materials, John E. Gilley, E. R. Kottwitz, G. A. Wieman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Hydraulic conditions required to initiate movement of unanchored residue materials are identified in the present study. Selected amounts of corn, cotton, pine needles, sorghum, soybean, sunflower, and wheat residue are placed in a flume on a sand surface, and flow is then introduced at the top of the flume in progressive increments. The discharge rate and flow velocity necessary to cause residue movement are determined. The ratio of critical flow depth to residue diameter, critical Reynolds number, critical shear stress, dimensionless shear stress, and boundary Reynolds number are calculated from hydraulic measurements. Regression equations are developed to relate dimensionless shear …

Acuta Enews June 1994, Vol. 23, No. 6

ACUTA Newsletters

In This Issue

Board report

President's message

White papers/blue papers

TFS takes aim at toll fraud

ITFS Monograph review

Lost on the Information Highway?

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 6, June 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Design And Analysis Of A Mode B And Mode Jd Satellite Earth Station, Dennis J. Hance

Theses and Dissertations

This thesis focuses on the design, integration, and analysis of an amateur radio service mode B and mode JD satellite earth station. Preliminary designs were investigated to determine the optimum configuration for the earth station. Modern digital modems, cabling structures, an 80386-based computer system, satellite tracking software, transmission and reception antennas, preamplifiers, and sophisticated performance measurement technologies were integrated into a functioning earth station. Initially, component availability and station design dictated the selection and acquisition of the requisite station equipment, integration of the transmitter, receiver preamplifiers, antennas, and computer equipment followed. Preliminary testing of the various components in the integration …

The Application Of Nepa Requirements To Cercla Remedial Actions, Connie L. Strobbe

Theses and Dissertations

This study investigated the application of National Environmental Policy Act NEPA requirements to Comprehensive Environmental Response, Compensation, and Liability Act CERCLA actions. Similarities in the documentation and public participation requirements of NEPA and CERCLA include identification and evaluation of alternatives and public participation. Differences include document contents and timing of public participation. This study presented four options for ensuring NEPA compliance at CERCLA sites. Option one included a Programmatic Environmental Impact Statement PEIS with subsequent combined FSEIS report for each subunit. Option two eliminated the PEIS, but retained a stand-alone NEPA document for each CERCLA subunit. Option three included a …

Knowledge‐Based Expert System For Concrete Mix Design, Yong Bai, Serji N. Amirkhanian

Civil and Environmental Engineering Faculty Research and Publications

In the United States, the American Concrete Institute method (ACI 211) is the most widely used concrete mix design. However, ACI 211 does not consider all factors regarding concrete mix design. The acceptance of a freshly mixed concrete depends on concrete quality control test results. If the results indicate that the concrete does not meet the specification, mix design adjustment must be made. Concrete mix design and adjustment are somewhat complicated and time‐consuming tasks that are performed best by experienced persons. In this project, a rule‐based expert system was developed to assist the user in concrete mix design, including the …

An Empirical Study Of Just-In-Time And Total Quality Management Principles Implementation In Manufacturing Firms In The U.S., Loknath Sriparavastu

Masters Theses

Literature in vogue points out that, in the last decade, American manufacturing companies came a long way in their renewed emphasis on the quality process. Justin- Time (JIT) and Total Quality Management (TQM) are the two magical phrases that are being frequently used in almost all the articles published on quality and productivity. Nevertheless, the literature does not provide any satisfactory explanation as to how JIT and TQM principles are implemented in the manufacturing industries.

This research, through a nationwide empirical survey, analyzed the effects of JIT and TQM strategies implementation. Survey results showed that implementing both JIT and TQM …

A Recursive Least Squares Training Algorithm For Multilayer Recurrent Neural Networks, Q. Xu, K. Krishnamurthy, Bruce M. Mcmillin, Wen Feng Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recurrent neural networks have the potential to perform significantly better than the commonly used feedforward neural networks due to their dynamical nature. However, they have received less attention because training algorithms/architectures have not been well developed. In this study, a recursive least squares algorithm to train recurrent neural networks with an arbitrary number of hidden layers is developed. The training algorithm is developed as an extension of the standard recursive estimation problem. Simulated results obtained for identification of the dynamics of a nonlinear dynamical system show promising results.

Identification Of Cutting Force In End Milling Operations Using Recurrent Neural Networks, Q. Xu, K. Krishnamurthy, Bruce M. Mcmillin, Wen Feng Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of identifying the cutting force in end milling operations is considered in this study. Recurrent neural networks are used here and are trained using a recursive least squares training algorithm. Training results for data obtained from a SAJO 3-axis vertical milling machine for steady slot cuts are presented. The results show that a recurrent neural network can learn the functional relationship between the feed rate and steady-state average resultant cutting force very well. Furthermore, results for the Mackey-Glass time series prediction problem are presented to illustrate the faster learning capability of the neural network scheme presented here