Mechanical Engineering Commons^™

Evaluation Of Extreme Wind Speeds In Relation To The Design Of Coastal Structures In Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

Five distribution functions, FT-I and Weibull with the exponent k = 0.75, 1.0, 1.4 and 2.0 respectively, have been applied to 25-year wind data collected between 1972 and 1996 at Tanga, Dar Es Salaam, Zanzibar and Mtwara Meteorological stations. One maximum value for every year from the full data record was drawn to constitute the annual maxima series for each station. For each of the stations, 2-, 50- and 100-year return wind speeds with corresponding 90% confidence intervals were computed. The distribution functions were fitted to the data by the Least Squares Method. Results from the study show that FT-I …

Production Innovation Through Design Methodology: Development Of A Fuel Pump For Motorists, E. Elias

Tanzania Journal of Engineering and Technology (TJET)

Design Methodology is a discipline of scientific engineering design for provision of solutions to user needs. It is composed of design models (showing the path/procedural steps of design) and design tactics (i.e. techniques, technologies and methods aiding the designer). When rigorously applied, design methodology leads to innovation of products and businesses.

The present paper describes how design methodology was applied to the development of a siphon device (Apump@) for motorists when in need to refill fuel in their vehicles away from petrol stations. The need for the device was realised through the method of Alooking around & deep thinking@ and …

The Effect Of System And Oxygen Partial Pressure On Single Coal Particle Heterogeneous Ignition Temperature Under Conditions Of Negligible Convection; Experimental Observation, H. Katalambula

Tanzania Journal of Engineering and Technology (TJET)

Abstract Under conditions of high volatile concentrations, the influence of oxygen concentration on single coal particle ignition becomes more significant. The high volatile concentration conditions have been simulated by employing a microgravity environment. Results show that under these conditions, the heterogeneous ignition temperature decreases faster with increasing oxygen concentration than under normal conditions. The ignition temperature also decreases with increasing system and oxygen partial pressure under both conditions. Generally, the system and oxygen partial pressure show similar and complimenting effects on ignition temperature.

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …

Estimation Of Volatile Cloud Density For Single Coal Particles Using Microgravity Condition, H. Katalambula

Tanzania Journal of Engineering and Technology (TJET)

Single coal particle’s volatile cloud density has been estimated by employing a microgravity condition. The volatile yield was found to decrease with pressure while the density was found to increase, indicating that volatiles occupies less space when under pressure and hence causing some volatiles to be retained within the particle. The volatile cloud density was also found to increase with volatile yield suggesting volatile composition changes with yield. The effect of heating rate on volatile yield was found to be the same as reported by other investigators where the yield increased with heating rate.

Measurement Of Markstein Lengths In Laminar Spherical Explosion Flames, E .M.J Mushi

Tanzania Journal of Engineering and Technology (TJET)

Schlieren photography was used to record the development of spherical flames in a combustion bomb. Flame speed and flame stretch were evaluated from the data and used to evaluate Markstein lengths and numbers. The results indicate a strong influence of both the spark discharge energy and equivalence ratio. Low spark discharge energy is observed to give rise to more unstable flames compared to high energy sparks. It is observed that for the range of energy tested, 80 and 400 mJ gave the best stability for the flames. For equivalence ratio less or equal to 1.225 an 80 mJ discharge results …

An Assessment Of Building Energy Efficiency Options At Horn Island Ranger Station, Gulf Islands National Seashore, Florida Solar Energy Center, Stephen Barkaszi

FSEC Energy Research Center®

As requested by Joe Martin of the National Park Service (NPS), Southeast Support Office, researchers from the Florida Solar Energy Center (FSEC) conducted a building energy efficiency assessment for the ranger station on Horn Island, Mississippi. The assessment included audits and inspections of the energy systems, building thermal performance, appliances, and energy use patterns. FSEC researchers Stephen Barkaszi and John Harrison conducted the audits and on-site inspections June 29 and June 30, 1999. The purpose of the assessment was to evaluate the facility and to present recommendations for improving the energy efficiency of the building. This report summarizes the information …

United States Patent: Method And System For Estimating The Tenderness Of A Meat Product, Maria Victoria Spadaro, Rosana Moreira, Jimmy Keeton, D. H. Allen

Department of Engineering Mechanics: Faculty Publications

A method for estimating the tenderness of a meat product is provided. The method includes determining the stress relaxation coefficient of a meat sample. One or more physical parameters of the meat sample are then determined from the stress relaxation coefficient. Diagnostic sensory characterization data, such as a numerical estimation of the meat's overall tenderness, is then determined for the meat sample. The physical parameters are then correlated to the diagnostic sensory characterization data, to allow the diagnostic sensory characterization data to be estimated solely from the measured physical parameters.

Development Of Cfd Algorithms For Transient And Steady Aerodynamics, Fergal Boyle [Thesis]

Other Resources

Research carried out in the United States and in Europe over the last 20 years has led to the development of the advanced propeller, a small-diameter, highly-loaded, multi-bladed, swept, variable-pitch propeller, that can achieve potential fuel savings of 30% over an equivalent technology turbofan engine at competitive speed and altitudes.

In this work an implicit finite-volume algorithm is developed for predicting the transient flow around an advanced propeller under asymmetric inflow conditions. The development of the unsteady propeller algorithm evolves from a family of methods for progressively more complex applications. In total six algorithms are developed: three steady and three …

Internally Constrained Mixtures Of Elastic Continua, Stephen M. Klisch

Mechanical Engineering

A treatment of internally constrained mixtures of elastic continua at a common temperature is developed. Internal constraints involving the deformation gradient tensors and the common mixture temperature are represented by a constraint manifold, and an internally constrained mixture of elastic continua is associated with each unique equivalence class of unconstrained mixtures. The example of intrinsic incompressibility of each constituent first proposed by Mills is discussed.

Energy Efficient Industrialized Housing Research Summary Of Fy1998 Activities (July 1998 - August 1999), Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

The objectives of this work are to increase the market share of energy-efficient housing by conducting field testing and monitoring, research, development, design assistance, and training activities in partnership with housing manufacturers, production builders, non-profits and related members of the housing industry.

Breakaway Steel Guardrail Post, Dean L. Sicking, John D. Reid, John R. Rohde

Department of Mechanical and Materials Engineering: Faculty Publications

A breakaway guardrail post includes upper and lower post sections spaced apart but connected by a breakaway joint. The joint is attached at one end to the upper post by a first fastener set and connected at a second end by a second fasteners set. Upon impact forces being applied to the upper post section, the first fastener fails and the upper post section rotates downwardly.

Evaluation Of Energy Efficient Improvements To Portable Classrooms In Florida, Florida Solar Energy Center, Michael Callahan

FSEC Energy Research Center®

Florida has over 25,000 portable classrooms in use around the state. Energy costs for these structures exceed $20 million a year - or about 11% of all energy-related expenditures for educational facilities. Research has also shown interior ventilation rates in these classrooms typically fall far below the recommended levels in ASHRAE Standard 62-1989.

To explore ways in which costs might be reduced and the physical learning environment improved, we conducted a two year experiment in two highly instrumented portable classrooms at Silver Sands Middle School in Volusia County. A series of retrofits, aimed to cut energy use and improve ventilation …

Collaborative Undergraduate Research, Hamid Davoodi, Frederick Just, Ali Saffar, Mohammad Noori, William W. Durgin

Office of the Provost Scholarship

A joint undergraduate research project between University of Puerto Rico at Mayagüez (UPRM) and Worcester Polytechnic Institute (WPI) started four years ago. Each year a group of students, varying between six and ten, from WPI will come to Puerto Rico to work with a group of students, varying from six to ten, from UPRM on a well defined research project. Although the topics of the projects have been different but all follow the same goal, Vibration Control of Structures by Utilizing Shape Memory Alloys. Each year the project starts on January and ends on May. Both groups of the students …

Simtrainer: A Management Training Tool, Wade Stark, Sema E. Alptekin

Industrial and Manufacturing Engineering

Abstract published of poster paper presented at conference.

Diagnostic Test Report On Florida Power Corporation's 15-Kwp Amorphous Silicon Photovoltaic System, Florida Solar Energy Center, Fsec Pvdg Division

FSEC Energy Research Center®

Florida Power Corporation (FPC) owns and operates a 15-peak-kilowatt (kWp) amorphous silicon photovoltaic (PV) system at its Econ substation in Orlando, Florida. The PV system, commissioned on August 23, 1988, was designed to generate power that would be injected directly to the FPC electric grid. The Solar Progress Generating Station was developed as part of FPC's interest in new power generation technologies. The PV system design and installation was a collaborative effort among FPC, the Florida Solar Energy Center (FSEC), Sandia National Laboratories (SNL), and the Electric Power Research Institute (EPRI).In March 1999, FPC informed FSEC that the PV system …

Scheduling Semiconductor Device Test Operations On Multihead Testers, Tali Freed, Robert C. Leachman

Industrial and Manufacturing Engineering

Past attempts to devise scheduling methods for the device test operations of semiconductor manufacturing firms fail to address a significant characteristic of multiple-head test systems—the dependency of processing rates on the lots processed simultaneously on the testers. Since the problem has never been modeled accurately in the scheduling literature, feasibility and performance of previously proposed scheduling methodologies for multihead testers may not be accurately assessed. In this paper, we describe the multihead tester scheduling problem, present an enumeration solution procedure, and illustrate the problems of previously suggested tester scheduling algorithms.

An Evaluation Of Ploughing Models For Orthogonal Machining, Daniel J. Waldorf, Richard E. Devor, Shiv G. Kapoor

Industrial and Manufacturing Engineering

An analytical comparison is made between two basic models of the flow of workpiece material around the edge of an orthogonal cutting tool during steady-state metal removal. Each has been the basis for assumptions in previous studies which attempt to model the machining process, but no direct comparison had been made to determine which, if either, is an appropriate model. One model assumes that a separation point exists on the rounded cutting edge while the other includes a stable build-up adhered to the edge and assumes a separation point at the outer extreme of the build-up. Theories of elastic-plastic deformation …

Evaluation Of Grid-Connected Photovoltaic Systems At The Nature Conservancy - Disney Wilderness Preserve, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This report presents the results of an evaluation of two grid-connected photovoltaic (PV) systems installed at the Disney Wilderness Preserve, in Kissimmee, FL. Conducted by the Florida Solar Energy Center (FSEC), this evaluation consisted of visual inspection of the equipment and installation, as well as electrical performance measurements on the PV array and operating system. Following lists the key results from this evaluation.

• The two grid-connected PV systems at this site were functioning properly and their operational performance is within expectations. The photovoltaic array installation is generally pleasing and complete, and uses listed equipment (PV panels, inverter and combiner box). …

Supervisory Control And Data Acquisition Experiment Using The Advanced Communications Technology Satellite - Lessons Learned, Florida Solar Energy Center, Carol Emrich

FSEC Energy Research Center®

Satellite Supervisory Control and Data Acquisition (SCADA) of a Photovoltaic (PV)/diesel hybrid system was tested using NASA's Advanced Communication Technology Satellite (ACTS) and Ultra Small Aperture Terminal (USAT) ground stations. The setup consisted of a custom-designed PV/diesel hybrid system, located at the Florida Solar Energy Center (FSEC), which was controlled and monitored at a remote hub via Ka-band satellite link connecting two USATs in a SCADA arrangement. The robustness of the communications link was tested for remote monitoring of the health and performance of a PV/diesel hybrid system, and for investigating load control and battery charging strategies to maximize battery …

Gauge Repeatability & Reproducibility Study For A 3-D Solder Paste Inspection System, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Due to the increased use of Ball Grid Arrays (BGAs) and fine pitch and ultra fine pitch Quad Flat Packages (QFPs), there is a dramatic increase in demand for solder paste inspection after the stencil printing process. The important response variables of the printing process are deposited solder paste volume, area, height and position. To identify and remove defects at the earliest possible process step, a 3-D solder paste inspection system should be used to monitor solder paste deposited on all pads on every board before component placement. An example is a fully automatic laser-based 3-D triangulation solder paste inspection …

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high volume surface mount assembly. Control of the amount of solder paste deposited is critical for fine pitch and ultra-fine pitch SMT assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% of SMT defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the deposited solder paste volume, area, and height. An experiment was conducted to investigate the effects of relevant process parameters on the amount of …

Supervisory Control And Data Acquisition Experiment Using The Advanced Communications Technology Satellite, Florida Solar Energy Center, Carol Emrich

FSEC Energy Research Center®

Satellite Supervisory Control and Data Acquisition (SCADA) was tested using the Advanced Communication Technology Satellite (ACTS) Ka-band signal and Ultra Small Aperture Terminal (USAT) ground stations. The SCADA system included a photovoltaic (PV)/diesel hybrid power generator designed to provide electricity to a rural community in a developing country. End-to-end baseline hardware checkout experiments have been completed. Results show that continuous two-second data transfers for real time monitoring can be completed with an error rate of less than 1%. The system recovers from simulated perturbations quickly and gracefully. Specifically, normal operation is resumed within 36 seconds following loss of power to …

Ole Miss Engineer 1999

Ole Miss Engineer

No abstract provided.

The Microchannel Flow Of A Micropolar Fluid, Guohua Liu

Doctoral Dissertations

Micro-channel flows have been computed to investigate the influence of Navier-Stokes formulation for the slip-flow boundary condition, and a micro-polar fluid model, respectively.

The results of the slip boundary condition show that the current methodology is valid for slip-flow regime (i.e., for values of Knudsen number less than approximately 0.1). Drag reduction phenomena apparent in some micro-channels can be explained by slip-flow theory. These results are in agreement with some computations and experiments.

An ad hoc micro-polar fluid model is developed to investigate the influence of micro effects, such as micro-gyration, in micro-scale flows. The foundation of the ad hoc …

Effect Of Interfacial Mobility On Flexural Strength And Fracture Toughness Of Glass/Epoxy Laminates, T. W. H. Wang, Frank D. Blum, Lokeswarappa R. Dharani

Chemistry Faculty Research & Creative Works

Mechanical testing and surface fractography were used to characterize the fracture of E-glass fiber reinforced epoxy composites as a function of the silane coupling agent used. gamma-Aminopropyltriethoxysilane (APS) and delta-aminobutyltriethoxysilane (ABS) were used because these have been shown to have different interfacial mobilities at multilayer coverage. The values of the properties studied generally increased from untreated c, as determined from a Mode I translaminar fracture toughness tests, for the untreated composites (10.5 ± 0.4 kJ/m2) was lower than that for the ABS-treated composites (14.3 ± 2.1 kJ/m2) which was lower than that for the APS-treated composites (17.1 ± 2.4 kJ/m2). …

Application Of A Fiber-Reinforced Continuum Theory To Multiple Deformations Of The Annulus Fibrosus, Stephen M. Klisch, Jeffrey C. Lotz

Mechanical Engineering

Accurate tissue stress predictions for the annulus fibrosus are essential for understanding the factors that cause or contribute to disc degeneration and mechanical failure. Current computational models used to predict in vivo disc stresses utilize material laws for annular tissue that are not rigorously validated against experimental data. Consequently, predictions of disc stress resulting from physical activities may be inaccurate and therefore unreliable as a basis for defining mechanical–biologic injury criteria. To address this need we present a model for the annulus as an isotropic ground substance reinforced with two families of collagen fibers, and an approach for determining the …

Suppression Of Post-Buckling Deflection And Panel-Flutter Using Shape Memory Alloy, Mohammad Tawfik Abo El So-Oud

Mechanical & Aerospace Engineering Theses & Dissertations

A novel concept proposed is the use of Shape Memory Alloy (SMA) to reduce the panel thermal deflection and flutter responses. SMA has unique ability to recover large prestrains completely when the alloy is heated (by aerodynamic heating in the present case) above the austenite start temperature A_s. During the recovery process, a large tensile recovery stress occurs if the SMA is restrained.

In this thesis, a panel subject to the combined aerodynamic and thermal loading is investigated. A nonlinear finite element model based on von Karman strain displacement relation is utilized to study the effectiveness of SMA …

The Mechtech Program: An Education And Training Model For The Next Century, Robert Forrant

New England Journal of Public Policy

The small-firm metalworking industry is routinely characterized by cutthroat competition and fierce privacy. Yet, since the late 1980s, the members of the western Massachusetts chapter of the National Tooling and Machining Association have participated in an education, training, and technology diffusion network characterized by a high degree of interfirm cooperation. Hundreds of workers and managers have take part in group training sessions and seminars. The reconstruction of the skill base is central to the MechTech apprenticeship program through which apprentices spend four years in participating firms, exiting the program as licensed machinists, tool and die makers, or moldmakers. In an …

Evaluation Of The Use Of Optical Fiber Thermometers For Thermal Control Of The Quench Module Insert, Matthew R. Jones, Jeffery T. Farmer, Shawn P. Breeding

Faculty Publications

Issues regarding the use of optical fiber thermometers to control heater settings in a microgravity vacuum furnace are addressed. It is desirable to use these probes in environments such as the International Space Station, because they can be operated without re-calibration for extended periods. However, the analysis presented in this paper shows that temperature readings obtained using optical fiber thermometers can be corrupted by emissions from the fiber when extended portions of the probe are exposed to elevated temperatures.