Mechanical Engineering Commons^™

Derivation Of An Expression That Defines The Pulling Forces In Relays With Small Operating Gaps, D. J. Chambega

Tanzania Journal of Engineering and Technology (TJET)

This paper derives an expression that defines magnitude of the pulling force developed in relays with small operating gaps, that is, when the length of the operating gap in between the yoke and the armature is small as compared to the area of the poles at the yoke. To obtain the expression, saturation of the core material is not considered. Results from the expression are then compared with those obtained experimentally. The comparison is found to deliver acceptable accuracy.

Effect Of Moisture And Loading Orientation On The Mechanical Properties Of Sorghum And Millet, E. L. Lazaro

Tanzania Journal of Engineering and Technology (TJET)

Uniaxial compression properties of sorghum and millet grain at different moisture contents (12–25% dry basis) and at different kernel orientation were investigated. These included: modulus of deformability, maximum compressive force, deformation and toughness at grain break point. Individual grain kernels of two varieties of sorghum, (Dionje and Jumbo) and one variety of pearl millet, (IM) at 12, 15, 20, and 25% moisture content dry basis (mc.db), were quasi-statically loaded using a J.J.universal tensile testing machine to their breaking point. The modulus of deformability, maximum compressive force required to initiate grain rupture and the grain toughness (energy absorbed at break point …

Dec 2002, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Report from Director on Leave Development Projects Liason Report

Experimental Nonlinear Modeling Of A Rotating Machine With An Oil Film Bearing, Chiou-Fong Chung, Pi-Cheng Tung, Chiang-Nan Chang

Journal of Marine Science and Technology–Taiwan

In this study the system identification method is applied to obtain a nonlinear equation for an oil film rotating system. The centrifugal force induced by an unbalanced mass is used as the input signal for identification, and the phase between the input signal and the measured output vibration amplitude is calculated to perform the identification. Stability analysis and system performance are evaluated by using the root locus and the Floquet-Liapunov theorem. Based on the model, the oil whirl of the journal bearing can be predicted. A comparison between the simulation results and some experimented data shows the feasibility of the …

Fast Convergence Control Approach For High Dimensional Chaotic Systems, Hsun-Heng Tsai, Chyun-Chau Fuh, Pi-Cheng Tung

Journal of Marine Science and Technology–Taiwan

A simple and efficient method for controlling high dimensional discrete-time chaotic systems is proposed in this paper. This method is implemented similar to the OGY method, and is feasible for practical experiments. The key component is to assign the eigenvalues of a linearized map by using the well-known pole placement technique. According to the Cayley-Hamilton theorem, the trajectory will converge to the desired fixed point after n iterations at most (n is the dimension of the map), if the real trajectory of the chaotic system falls within the neighborhood of the desired fixed point. The proposed approach improves the convergence …

Application Of The Force Control On The Working Path Tacking, Sun-Run Wang, Zhi-Zhong Qiao, Pi-Cheng Tung

Journal of Marine Science and Technology–Taiwan

For the application of tracking the path on workpieces, the CCD (Charge Couple Device) identificating system is generally used as one of the popular resolutions. However, the implementation of CCD identificating system is complex and environmental-limited. This study presents a compliant motion controller by using the end-effector installed with a force sensor. This results the smoothly path tracking on a workpiece. By applying the algorithm of Fuzzy into this compliant motion, the compliant control is improved and the path on the workpiece is found more quickly and accurately. A radius compensating method is used to correct the measured data. The …

On-Chip Actuation Of An In-Plane Compliant Bistable Micromechanism, Michael S. Baker, Larry L. Howell

Faculty Publications

A compliant bistable micromechanism has been developed which can be switched in either direction using on-chip thermal actuation. The energy storage and bistable behavior of the mechanism is achieved through the elastic deflection of compliant segments. The Pseudo-Rigid-Body Model was used for the compliant mechanism design, and for analysis of the large deflection flexible segments. To achieve on-chip actuation, the mechanism design was optimized to allow it to be switched using linear motion thermal actuators. The modeling theory and analysis are presented for three design iterations, with two iterations fabricated in the MUMP's process and the third in the SUMMiT …

Iodat Analysis Content In Cooking Ingredients Using Iodometry And X-Ray Fluorescence Methods., Nelson Saksono

Makara Journal of Technology

Iodat Analysis Content in Cooking Ingredients Using Iodometry and X-ray Fluorescence Methods. Salt iodization program using iodine fortification into salt method is the best method that is effective and economical to overcome the problems caused by iodine deficiency. However in, its development there are some issues clamed that the use of iodized salt is ineffective since iodine content reduces, even disappear when the salt mix with other cooking ingredients. In order to investigated the existence of iodine in cooking ingredients, a research applying iodometry and X-ray fluorescence methods was carry out. The result obtained by iodometry method showed decreases in …

Emission Gas Reducer On Motor Vehicle, Automobile, Light Engine Of Boat And Stationary Combustion Engine., I Gusti Bagus Wijaya Kusuma

Makara Journal of Technology

Emission gas reducer on motor vehicle, automobile, light engine of boat and stationary combustion engine. The use of motor vehicle should be followed by protection against damages on the environment, since the exhaust gas from combustion engine has significantly affect on air and environmental pollution. One method to solve the problems in air pollution has been done by using a re-heater designed in Mechanical Engineering Department, University of Udayana. In accordance to the test on the re-heater, it can be seen very clear that the re-heater has significantly reduce the CO emission of about 54%. It also reduces the CO2 …

Application Of Remote Sensing For Mapping Soil Organic Matter Content, Bangun Muljo Sukojo, Wahono Wahono

Makara Journal of Technology

Application of Remote Sensing for Mapping Soil Organic Matter Content. Information organic content is important in monitoring and managing the environment as well as doing agricultural production activities. This research tried to map soil organic content in Malang using remote sensing technology. The research uses 6 bands of data captured by Landsat TM (Thematic Mapper) satellite (band 1, 2, 3, 4, 5, 7). The research focuses on pixels having Normalized Difference Soil Index (NDSI) more than 0.3. Ground-truth data were collected by analysing organic content of soil samples using Black-Walkey method. The result of analysis shows that digital number of …

Optimation Model Of Planning Investment Dockyard With Approach Multi Objective Goal Programming, Ali Azhar

Makara Journal of Technology

Optimation model of planning investment dockyard with approach multi objective goal programming. The purpose of this research is to determine decision variable, goal function, alternative priority and achievement function in investment planning. From this optimation component, the model of ship yard investment planning could be achieved. The model of developed model in this research was the optimation of ship yard investment planning using multi objective goal programming approach. The model consist of 5 decision variable, 11 goal function, 2 alternative priority and 11 achievement functions. The model implementation was done toward PT ASSI investment planning. The calculation using from Quantitative …

Self-Ignition Properties Of Peat, Palm Shell Fibre And Woods, Yulianto Sulistyo Nugroho

Makara Journal of Technology

Self-ignition properties of peat, palm shell fibre and woods. Forest fire is one of the greatest environmental problems faced by Indonesia. Forest fires have destroyed million hectares of forest and land which cause economic loss, social problems including smoke related diseases and environmental disaster with long time consequences. The exothermic reactions of forest fuels that lead to fire can be initiated by a piloted flame and low-temperature oxidation mechanism. This paper presents the results of low temperature oxidation studies using forests fuel samples i.e. palm shell fibre, peat, woods and low-rank coal. The measured values of the critical oven temperatures …

The Use Of 2d Plastic Grating For Surface Profile And Dimension Manufacture Product Measurements By Using Ndt Moiré Technique, Retno Wigajatri P., Dini Andiani

Makara Journal of Technology

The Use of 2D Plastic Grating for Surface Profile and Dimension Manufacture Product Measurements by Using NDT Moiré Technique. Research of measuring the shape and dimension of object using the moiré technique have been done. Measurement have been made by observing the moiré space as a result of interaction between grating and its shadow casted on the object’s surface caused by the projector lamp with CCD camera. The acquired data was further processed by way of off-line. By successive phase shifts that is π/2, π dan 3π/2 towards the table tennis ball at the distance of 48 cm from the …

Solar Dhw Collector Thermal Performance Ratings, Florida Solar Energy Center, John Harrison

FSEC Energy Research Center®

Thermal performance ratings, derived from the FSEC testing and certification program, are a useful tool in comparing the efficiency and economics of various flat-plate solar collectors. Since collectors used in domestic hot water (DHW) systems typically operate in the intermediate temperature range (1200F-1600F), this is the rating provided for comparisons. It must be stressed that these comparisons are only a guide and should not be considered as a rank ordering of collectors. Such considerations as component sizing and proper installation procedures are equally important in determining a system's overall efficiency. In addition, because of the variability of weather conditions, instrumentation …

Switching Decisions For Diversity Antennas Using Autoregressive Techniques, Sebastian Mani Puthenpurayil

Theses and Dissertations - UTB/UTPA

Decision-making on switching for diversity antennas has been given considerable attention in recent times in mobile radio communications. Due to multipath propagation of radio waves the signals undergo a phenomenon known as fading and there will be considerable reduction in the average signal strength. By having multiple antennas in the receiver or transmitter the signal strength can be improved by switching back and forth to the antenna that has the maximum signal strength. In this thesis we have used linear prediction method for making decisions on which antenna gives the maximum signal strength. Linear prediction is applied on a single …

Resonance Detection And Acoustic Behaviour In Polymer Intake Manifolds, Amrith Ramanan

Masters Theses

The Automotive Industry, over the last few years, has been placing major emphasis on the use of lightweight components in engines as well as other structural components. The material for these lightweight components are being chosen in such a way that they require minimal secondary operations to place the components in service. One area that has developed is the use of Polymer (Plastic) Intake Manifolds for Internal Combustion engines. Plastics meet all the criteria for quality low cost production with a minimum weight component. Plastic intake manifolds, however, have been found to be excessively noisy in operation. This noise can …

Development Of A Simulation For The Prediction Of Pvdf Surface Velocity Sensor Response For Vibrating Beams And Rectangular Plates, Brian C. Zellers

Masters Theses

A simulation for the prediction of Polyvinylidene Flouride (or PVDF) sensor charge response to structural vibration displacements of beam and rectangular plate structures was developed. The simulation uses measured vibration displacements from an actual structure using point sensors (accelerometers) assembled in an array on the surface of the structure. The PVDF sensor charge output equation was written for a PVDF film of constant spatial sensitivity so that numerical analysis tools in Matlab® can be used to solve the equation. Preliminary experimental results showed that the bending strain component, due to transverse vibration displacements, is the dominant term for both the …

Using The Boundary Element Method For Prediction Of Sound Radiated From An Arbitrarily Shaped Vibrating Body, Mark J. Christensen

Masters Theses

The Boundary Element Method can be used to predict sound pressure levels radiated from an arbitrarily shaped vibrating body. Using the Direct, Indirect and Approximation formulation one can solve such an ‘exterior’ acoustic problem. In this work, the Direct formulation was chosen. The two major methods employed for implementation of this formulation are the Combined Helmholtz Integral Equation Formulation (CHIEF) and the Burton–Miller Method. Since the CHIEF method was easier to program and adapt to changes, it was decided that the CHIEF method would be the focus of this research. Using the CHIEF method as a guide, a computer simulation …

Coarsening Dynamics Of Biaxial Nematic Liquid Crystals, Nikolai V. Priezjev, Robert A. Pelcovits

Mechanical and Materials Engineering Faculty Publications

We study the coarsening dynamics of two- and three-dimensional biaxial nematic liquid crystals, using Langevin dynamics. Unlike previous work, we use a model with no a priori relationship among the three elastic constants associated with director deformations. Biaxial nematics possess four topologically distinct classes of defects, three of which have half-integer charge, while the fourth, which plays a minor role in coarsening, is of integer charge. We find a rich variety of coarsening behavior, including the presence of one, two, or three of the half-integer classes at late times, depending on the relative values of the elastic constants and the …

Development And Design Of Constant-Force Mechanisms, Brent Lewis Weight

Theses and Dissertations

This thesis adds to the knowledge base of constant-force mechanisms (CFMs). It begins by reviewing past work done in the area of CFMs and then develops new nondimensionalized parameters that are used to simplify the calculations required to design a CFM. Comparison techniques are then developed that utilize these non-dimensionalized parameters to compare mechanisms based on stiffnesses, percent constant-force, actual lengths, normal displacements, and feasible design orientations. These comparison techniques are then combined with optimization to define new mechanisms with improved performance and range of capabilities. This thesis also outlines a design process, methods to identify mechanisms that are suitable …

Flexible Roofing Facility: 2001 Summer Test Results, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

The Flexible Roof Facility (FRF) is a test facility in Cocoa, Florida designed to evaluate five roofing systems at a time against a control roof with dark shingles. The intent of the testing is to evaluate how roofing systems impact summer residential cooling energy use and peak demand. In the summer of 2001, the following roofing systems were tested.

Cell # Description

1. Weathered white barrel tile with sealed attic
2. Double roof with radiant barrier, sealed attic and insulated roof deck
3. High reflectance brown metal shingle with vented attic
4. Terra cotta barrel tile with vented attic
5. Dark shingles with standard attic …

Energy And Environmental Integration Through A Green Municipality Designation, Florida Solar Energy Center, Eric Martin

FSEC Energy Research Center®

Most local green building programs in existence seek to bestow a "green designation" on a builder, building owner, or developer with residential, commercial, and development standards. Municipalities, however, play an important role in making green building become "business as usual" rather than a conscious choice made by few. Municipalities can set an example to the community by incorporating green building techniques in the construction and operation of public and government buildings, play a vital role in community education, and can create incentives and mandates to foster green building within the community. Florida's green building program has set out to create …

Focus On The Job In Hand: When Usb 2.0 Technology Is Employed In Test And Measurement Signal Analyzer Hardware, Life Can Become So Much More Simple, Charles Birdsong, Dave Galyardt, James Zhuge

Mechanical Engineering

No abstract provided.

Comparison Of Radiated Power From Structurally Different Violins, Lily M. Wang, Courtney B. Burroughs

Durham School of Architectural Engineering and Construction: Faculty Publications

The acoustic power has been determined from intensity measurements on three structurally different violins: a Scherl and Roth student violin, Hutchins' SUS29S, and Hutchins' mezzo violin SUS 100. While each violin was bowed with an open-frame mechanical bowing machine, the intensity measurements were made by scanning each side of the bowing machine with an intensity probe. One-third octave band sound power levels of the acoustic radiation from each of the three instruments as each of the four open strings is bowed show that the structurally different mezzo violin produces greater power at low frequencies when the lowest (G) string is …

A Semi-Infinite Interfacial Crack Between Two Bonded Dissimilar Elastic Strips, Xiang-Fa Wu, E. Lilla, W.-S. Zou

Department of Engineering Mechanics: Faculty Publications

This paper is concerned with a semi-infinite interfacial crack between two bonded dissimilar elastic strips with equal thickness. Solutions for the complex stress intensity factor (SIF) and energy release rate (ERR) are obtained in closed form under in-plane deformations. During the procedure, the mixed boundary-value problem is reduced by means of the conformal mapping technique to the standard Riemann–Hilbert problem. In some limiting cases, the present solutions can cover the results found in literature.

Mapping The Mesoscale Interface Structure In Polycrystalline Materials, Brent L. Adams, C. L. Bauer, D. Casasent, A. Morawiec, S. Ozdemir, A. Talukder, Chialin T. Wu

Faculty Publications

This work was supported primarily by the MRSEC Program of the National Science Foundation under Award Numbers DMR-9632556 and DMR-0079996. A new experimental approach to the quantitative characterization of polycrystalline microstructure by scanning electron microscopy is described. Combining automated electron backscattering diffraction with conventional scanning contrast imaging and with calibrated serial sectioning, the new method (Mesoscale Interface Mapping System, MIMS) recovers precision estimates of the 3-dimensional idealized aggregate function G(x). This function embodies a description of lattice phase and orientation (limiting resolution ~ 1 degree) at each point x (limiting spatial resolution ~ 100 nanometers), and therefore contains a complete …

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (Aug. 01 – Oct. 31, 2002), Yingtao Jiang, Bingmei Fu, Woosoon Yim

Transmutation Sciences Materials (TRP)

After two month intensive work in LANL, some preliminary sensor calibration curves have been obtained. Further data analysis shall be performed to assess the theoretical and measured data. Also, a new experimental apparatus shall be designed and located in UNLV to continue the left work.

Technical Progress:

• A set of calibration curves of voltage vs. temperature ranging from 300⁰C to 500⁰C under various oxygen concentrations in liquid LBE for the YSZ oxygen sensor has been obtained and has been reported in one paper.

• A meeting with LBE committee and other faculty members in AAA …

Distributions Of Nobel Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Mesoporous silicananostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalyticproperties for CO–CH₄CO–CH₄CO–CH₄ combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors.

Distributions Of Noble Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Mesoporous silica nanostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalytic properties for CO–CH4 combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors.

Oct 2002, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Husker Harvest Days Fund Raising Interim Director