Engineering Commons^™

An Overview Of Mav Research At Brigham Young University, Timothy W. Mclain, Randal W. Beard, D. Blake Barber, Nathan B. Knoebel

Faculty Publications

This paper summarizes research efforts at Brigham Young University related to the control of miniature aerial vehicles (MAVs). Recent results in the areas of vector field path following, precision landing and target prosecution, target localization, obstacle detection and avoidance, tailsitter aircraft control, and cooperative control are presented.

High Temperature Heat Exchanger Project: Quarterly Progress Report January 1, 2007 Through March 31, 2007, Anthony Hechanova

Publications (NSTD)

• The variation of sulfur dioxide production (throughput) of the baseline design of the Ceramatec sulfuric acid decomposer with total mass flow rate of reacting flow has been calculated. According to the calculations, the sulfur dioxide production increases as the total mass flow rate of reacting flow increases regardless of the fact that decomposition percentage of sulfuric trioxide decreases. A parametric study of the baseline design of the Ceramatec sulfuric acid decomposer was performed.

• The thermal performance using various channel geometries for the decomposer was studied. The baseline design (straight channels) has 89.5% thermal efficiency while the thermal efficiency …

Closing The Gap: Getting Full Performance From Residential Central Air Conditioners, Task 4 - Develop New Climate-Sensitive Air Conditioner, Simulation Results And Cost Benefit Analysis, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This study evaluated the impacts of conventional and advanced cooling and dehumidification equipment on residential indoor humidity levels and annual energy consumption using whole building computer simulations. The life-cycle cost premium for the various advanced systems was also estimated. Building models were developed for a standard HERS Reference house, meant to represent current residential construction practice, and a High-Efficiency house that would likely qualify for a federal tax credit. The different houses were simulated in seven southeastern U.S. cities and with two ventilation/infiltration scenarios: 1) variable or natural infiltration alone, and 2) mechanical ventilation that complied with ASHRAE Standard 62.2-2004. …

Mitigating The Impacts Of Uncontrolled Air Flow On Indoor Environmental Quality And Energy Demand In Non-Residential Buildings, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This project builds on previous field research in Florida that has demonstrated the significant impact that uncontrolled air flows (UAFs) have on indoor environmental quality (IEQ) and energy use in small commercial buildings, a large but poorly understood segment of the nation's building stock. The goal of this project was to extend that research to a national scale by assessing the importance of UAFs in a sample of 25 commercial buildings in New York State. The differences in climate and construction techniques between New York and Florida are expected to bound the range conditions typically found on a national basis. …

Trials Bike Frame Concept, David Boboltz, Rob Harmer, Caleb Vanderveen

Honors Theses

Development of a Concept Trials Frame was a mechanical engineering design project that developed a new bicycle frame that has the strength and durability to be used for trials bike riding. The scope of the project was placed solely on the bicycle's frame. Current frames were analyzed based on their strength, durability, stiffness, weight, and appearance. These factors were ranked for importance and became the performance targets for the new frame. Several designs that utilize elastic strain energy to increase performance were brainstormed. Following SolidWorks modeling, equivalent impact loads were calculated using several analytical methods. These loads were then applied …

Panoramic Video For Efficient Ground Surveillance From Small Unmanned Air Vehicles, Joseph Aaron Jackson

Theses and Dissertations

As unmanned air vehicle (UAV) utilization increases in Wilderness Search and Rescue (WiSAR) efforts, onboard sensors yielding more information will be desired. UAVs can assist WiSAR efforts by accelerating the ground search process through returning quality aerial footage of the terrain. Additionally, tracking the progress of a search by populating a digital map with video resolution data increases confidence that a comprehensive search of the region has been made. This thesis presents methods for acquiring video from multiple video sensors and fusing them into a single rendered video stream as a Virtual Gimbal. The panoramic video stream is the first …

Development Of A Biofidelic 'Legform' Impact Test Device, John Davis, Peter Schuster

Mechanical Engineering

Current EuroNCAP test specifications attempt to predict pedestrian lower limb injury in a lateral impact with a rigid legform test device developed by the UK's TRL (Transportation Research Lab). Research shows that the measurements taken from this device (knee bending angle, knee shear, and upper tibia acceleration) do not necessarily correspond to accurate injury prediction. Recent research suggests that the primary improvement to the current test device would be a flexible legform, or one that has more biofidelity (i.e., simulates actual human lower limb response).

The work presented in this paper first reviews current legforms developed for pedestrian impact testing, …

Coupled-Mode Theory For Stimulated Raman Scattering In High-Q/Vm Silicon Photonic Band Gap Defect Cavity Lasers, Xiaodong Yang, C. W. Wong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We examine the dynamics of stimulated Raman scattering in designed high-Q/V_m silicon photonic band gap nanocavities through the coupled-mode theory framework towards optically-pumped silicon lasing. The interplay of other X⁽³⁾ effects such as two-photon absorption and optical Kerr, related free-carrier dynamics, thermal effects, as well as linear losses such as cavity radiation and linear material absorption are included and investigated numerically. Our results clarify the relative contributions and evolution of the mechanisms, and demonstrate the lasing and shutdown thresholds. Our studies illustrate the conditions for continuous-wave and pulsed highly-efficient Raman frequency conversion for practical realization in monolithic silicon …

Stochastic Chaotic Motion Of Ships In Beam Seas, Li-Qin Liu, You-Gang Tang, Hong-Xia Li

Journal of Marine Science and Technology–Taiwan

The stochastic chaotic motion and the threshold intensity of the external excitation force for onset of chaos of the ships in random beam waves are studied by the nonlinear stochastic dynamics theory. The random differential equation of ships’ rolling motion is established with considering the nonlinear damping, nonlinear restoring moment and the white noise wave excitation. The random Melnikov mean-square criterion is used to determine the threshold intensity for onset of chaos. The probability density function of the rolling response is calculated through solving the stochastic differential equations by applying the path integral method in the chaotic region. It is …

Study Of The Flow Field And Scalar Transport Of Indoor Ventilating Space Under The Impact Of Coanda Vortex, Je-Ee Ho, Hong-Tsu Young

Journal of Marine Science and Technology–Taiwan

The vortex in the flow field will isolate the space to further reduce the indoor air exchange and convective efficiency. The Coanda vortex accompanied by the inlet jet usually has the most active effect on the flow field. Both its location and scalar size which are primary determined by the strength of the injected flow and the arrangement of inlet; outlet will deeply affect the air-exchange volume, even reduce the available ventilation space. A 2-D turbulent model with SIMPLE method is set up to simulate the air motion of indoors; it can easily describe the working of Coanda vortex in …

Applications Of Search Theory To Coordinated Searching By Unmanned Aerial Vehicles, Steven R. Hansen

Theses and Dissertations

Concepts in optimal search theory have been used in human-based aerial search since World War II. This thesis addresses the technical and theoretical issues necessary to apply this crucial theory to search path planning for Small Unmanned Aerial Vehicles (SUAVs). A typical search often requires that more than one target be located. Accordingly, a method is presented to locate multiple targets in three dimensions, as well as to differentiate between them. However, significant error can be present when locating targets from an airborne platform, and the idea of target quality is also introduced as a way to describe the reliability …

Calibration Of Atomic Force Microscope Cantilevers Using Piezolevers, Saltuk B. Aksu, Joseph A. Turner

Department of Engineering Mechanics: Faculty Publications

The atomic force microscope (AFM) can provide qualitative information by numerous imaging modes, but it can also provide quantitative information when calibrated cantilevers are used. In this article a new technique is demonstrated to calibrate AFM cantilevers using a reference piezolever. Experiments are performed on 13 different commercially available cantilevers. The stiff cantilevers, whose stiffness is more than 0.4 N/m, are compared to the stiffness values measured using nanoindentation. The experimental data collected by the piezolever method is in good agreement with the nanoindentation data. Calibration with a piezolever is fast, easy, and nondestructive and a commercially available AFM is …

Robot For Surgical Applications: United States Patent No. Us 7,199,545 B2, Dmitry Oleynikov, Shane Farritor, Adnan Hadzialic, Stephen R. Platt

Department of Mechanical and Materials Engineering: Faculty Publications

The present invention provides a robot for use inside an open abdominal cavity during minimally-invasive surgery. The robot may include various sensors, imaging devices or manipulators.

Observations Of Structural Damage Caused By Hurricane Katrina On The Mississippi Gulf Coast, Christopher D. Eamon, Patrick Fitzpatrick, Dennis D. Truax

Civil and Environmental Engineering Faculty Research Publications

The loads associated with Hurricane Katrina led to the destruction or severe damage of approximately 130,000 homes and over 200 deaths in the state of Mississippi. This paper discusses the results of a field inspection of structural damage along the state’s Gulf Coast area caused by this hurricane. It was found that reinforced concrete, steel frame, and heavy timber structures generally performed well, with minimal structural damage. Precast concrete, light frame wood, and bridge structures generally performed poorly. Non-structural components of all building types, in particular facades and interior partitions subjected to storm surge, were typically destroyed. For various structures, …

Investigation Of The Lead-Free Solder Joint Shear Performance, James Webster, Jianbiao Pan, Brian J. Toleno

Industrial and Manufacturing Engineering

Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The purpose of this study is to investigate the effects of reflow profile and thermal shock on the shear performance of eutectic SnPb (SnPb) and Sn3.0Ag0.5Cu (SAC305) solder joints. Test boards were assembled with four different sized surface mount chip resistors (1206, 0805, 0603 and 0402). Nine reflow profiles for SAC 305 and nine reflow profiles for SnPb were developed with three levels of peak temperature (12ºC, 22ºC, and 32ºC above solder liquidus temperature, or 230ºC, 240ºC, and 250ºC for SAC …

Lower Extremity Mechanics During Cutting Tasks In Different Shoe-Turf Combinations, Rafael Garcilazo

McNair Scholars Research Journal

The demands placed on the lower extremity when performing jumping and cutting maneuvers are depending, in part, on the interaction between the playing surface and the athlete's footwear. Higher demands are likely to result in increased incidence of injury, so for safety reasons it is important to quantify how the shoe-turf interface affects joint loads. The purpose of this study is to compare the forces on the lower extremity while landing and side cutting (rapid direction change at approximately 45 degrees) on artificial football turf with different styles of football cleats.

Ole Miss Engineer 2007

Ole Miss Engineer

No abstract provided.

Computational Constitutive Model For Predicting Nonlinear Viscoelastic Damage And Fracture Failure Of Asphalt Concrete Mixtures, Yong-Rak Kim, D. H. Allen, D. N. Little

Department of Engineering Mechanics: Faculty Publications

A computational constitutive model was developed to predict damage and fracture failure of asphalt concrete mixtures. Complex heterogeneity and inelastic mechanical behavior are addressed by the model by using finite-element methods and elastic– viscoelastic constitutive relations. Damage evolution due to progressive cracking is represented by randomly oriented interface fracture, which is governed by a newly developed nonlinear viscoelastic cohesive zone model. Computational simulations demonstrate that damage evolution and failure of asphalt concrete mixtures is dependent on the mechanical properties of the mixture. This approach is suitable for the relative evaluation of asphalt concrete mixtures by simply employing material properties and …

Uncertainty And Error In Laser Triangulation Measurements For Pipe Profiling, Michael Kenneth Swanbom

Doctoral Dissertations

Underground pipeline infrastructure often receives insufficient attention and maintenance. Those responsible for ensuring the continuing functionality of this infrastructure primarily use subjective information in their decision making, and standards defining the level of damage acceptable before repair or replacement are difficult to implement. Laser pipe profiling is a relatively new technology that has emerged to take a step toward the objective assessment of buried assets. A laser profiler is a device that traverses a section of pipe, taking measurements of radius around the circumference of the inner pipe wall at multiple locations along the length of the pipe. The accuracy …

Simple: System Automatic Essay Assessment For Indonesian Language Subject Examination, Anak Agung Putri Ratna, Bagio Budiardjo, Djoko Hartanto

Makara Journal of Technology

SIMPLE: System Automatic Essay Assessment for Indonesian Language Subject Examination. Evaluation of study of a student is a very important aspect of an educational process. Evaluation is aimed at measuring the level of student understanding of the given lecture materials. Measuring student understanding of the course material, using essay-type exam, is generally used as the evaluation tool. In this essay-type exam, the student has to answer questions using sentences, whereby choices of possible answers are not indicated. The student has to answer the questions with his/her sentences. The answers may vary, since it reflects the student’s best thoughts of the …

Utilization Of Bagasse Cellulose For Ethanol Production Through Simultaneous Saccharification And Fermentation By Xylanase, M. Samsuri, Misri Gozan, R. Mardias, M. Baiquni, Heri Hermansyah, Anondho Wijanarko, Bambang Prasetya, M. Nasikin

Makara Journal of Technology

Utilization of Bagasse Cellulose for Ethanol Production through Simultaneous Saccharification and Fermentation by Xylanase. Bagasse is a solid residue from sugar cane process, which is not many use it for some product which have more added value. Bagasse, which is a lignosellulosic material, be able to be use for alternative energy resources like bioethanol or biogas. With renewable energy resources a crisis of energy in Republic of Indonesia could be solved, especially in oil and gas. This research has done the conversion of bagasse to bioethanol with xylanase enzyme. The result show that bagasse contains of 52,7% cellulose, 20% hemicelluloses, …

Determining Equi-Biaxial Residual Stress And Mechanical Properties From The Force-Displacement Curves Of Conical Microindentation, J. Yan, X. Chen, Anette M. Karlsson

Mechanical Engineering Faculty Publications

An alternative, improved method to determine mechanical properties from indentation testing is presented. This method can determine the elastic modulus, yield strength and equi-biaxial residual stress from one simple test. Furthermore,the technique does not require the knowledge of the contact area during indentation, a parameter that is hard to determine for highly elastic material. The evaluation technique is based on finite element analyses, where explicit formulations are established to correlate the parameter groups governing indentation on stressed specimens.

Biodesulphurization Within Natural Gas In Oil And Gas Field, Sri Astuti Rahayu, M. Fierdaus, Syafrizal Syafrizal, M. Udiharto

Makara Journal of Technology

The presence of sulphur compounds in natural gas can interfere to the quality of natural gas. The decline of combustion gas capacity, metal instrument corrosion in gas piping, and the environmental pollution from gas emission can affect by their presence. Bio-filter is one of the methods that selected to reduce sulphur content in natural gas. A lab scale study of hydrogen sulphide reduction in natural gas had conducted in oil and gas field using bio-filter method. The bio-filter system (±1 L volume) contains an active carbon and thiosulphide medium as a substrate, Thiobacillus thioparus as a single culture of sulphur …

Warpage Behavior Of 7075 Aluminum Alloy Extrusions, Omar S. Es-Said, T. M. Ruperto, S. L. Vasquez, A. Y. Yue, D. J. Manriquez, J. C. Quilla, S. H. Harris, S. Hannan, J. Foyos, E. W. Lee, B. Pregger, N. Abourialy, J. Ogren

Mechanical Engineering Faculty Works

Extruded I sections of 7075-T6 aluminum were machined into four different sections shapes: L, short depth L, T, and short depth 7. The furnace was preheated to 416 degrees C (780 degrees F) and the samples were placed inside. The temperature was raised to 471 degrees C (880 degrees F) and then the samples were quenched in either a 30% polyalkylene Glycol solution or water, both at 15 degrees C (59 degrees F). Points on the distorted samples were recorded before and after the solution treatment; the difference between the measurements indicated the extent of warpage.

Production Of Medium Chain Length Polyhydroxyalkanoates From Oleic Acid Using Pseudomonas Putida Pga1 By Fed Batch Culture, Sidik Marsudi, Irene K.P. Tan, Seng Neon Gan, K. B. Ramachandran

Makara Journal of Technology

Bacterial polyhydroxyalkanoates (PHAs) are a class of polymers currently receiving much attention because of their potential as renewable and biodegradable plastics. A wide variety of bacteria has been reported to produce PHAs including Pseudomonas strains. These strains are known as versatile medium chain length PHAs (PHAs-mcl) producers using fatty acids as carbon source. Oleic acid was used to produce PHAs-mcl using Pseudomonas putida PGA 1 by continuous feeding of both nitrogen and carbon source, in a fed batch culture. During cell growth, PHAs also accumulated, indicating that PHA production in this organism is growth associated. Residual cell increased until the …

Mechanical Study On Using Of Accr Thermal Conductor At 500 Kv Sutet, Suprihadi Prasetyono

Makara Journal of Technology

Mechanical Study on using of ACCR Thermal Conductor at 500 kV SUTET. At the height of electricity demand increasing recently, circumstance of environment more limited and also expense of high investment, making thermal conductor (conductor thermal resistance) considered to be one of alternative in the electricity transmission bottlenecks. These days it has been developed thermal conductor ACCR (Aluminium Conductor Composite Reinforced) which can operate with temperature up to 240oC, so that making the current carrying capacity being higher than conventional conductor. This research aimed to study load current leading to mechanical characteristic ACCR conductor included tension, length of elongation and …

Micro Synthetic Jets As Effective Actuator, Mehti Koklu

Mechanical & Aerospace Engineering Theses & Dissertations

Synthetic jets have previously been studied as actuators for external macroflow control and recently been proposed for internal microflow applications. Despite the wide variety of the potential applications of synthetic jet actuators, the majority of the studies have been done at macro scales. Furthermore, there has not been any design methodology that addresses the effectiveness of the micro synthetic jet actuators. Bearing these needs in mind, a micro synthetic jet configuration is considered in a microscale environment where Kn number is less than 0.1 and more than 0.001. Flowfields are simulated by solving the compressible Navier-Stokes equations. The wall boundary …

Derivation And Application Of A Conserved Orbital Energy For The Inverted Pendulum Bipedal Walking Model, Jerry E. Pratt, Sergey V. Drakunov

Publications

We present an analysis of a point mass, point foot, planar inverted pendulum model for bipedal walking. Using this model, we derive expressions for a conserved quantity, the “Orbital Energy”, given a smooth Center of Mass trajectory. Given a closed form Center of Mass Trajectory, the equation for the Orbital Energy is a closed form expression except for an integral term, which we show to be the first moment of area under the Center of Mass path. Hence, given a Center of Mass trajectory, it is straightforward and computationally simple to compute phase portraits for the system. In fact, for …

Efficient Sampling For Non-Intrusive Polynomial Chaos Applications With Multiple Uncertain Input Variables, Serhat Hosder, Robert W. Walters, Michael Balch

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The accuracy and the computational efficiency of a Point-Collocation Non-Intrusive Polynomial Chaos (NIPC) method applied to stochastic problems with multiple uncertain input variables has been investigated. Two stochastic model problems with multiple uniform random variables were studied to determine the effect of different sampling methods (Random, Latin Hypercube, and Hammersley) for the selection of the collocation points. The effect of the number of collocation points on the accuracy of polynomial chaos expansions were also investigated. The results of the stochastic model problems show that all three sampling methods exhibit a similar performance in terms of the the accuracy and the …

Construction Of Short-Length High-Rates Ldpc Codes Using Difference Families, Deny Hamdani, Ery Safrianti

Makara Journal of Technology

Low-density parity-check (LDPC) code is linear-block error-correcting code defined by sparse parity-check matrix. It is decoded using the massage-passing algorithm, and in many cases, capable of outperforming turbo code. This paper presents a class of low-density parity-check (LDPC) codes showing good performance with low encoding complexity. The code is constructed using difference families from combinatorial design. The resulting code, which is designed to have short code length and high code rate, can be encoded with low complexity due to its quasi-cyclic structure, and performs well when it is iteratively decoded with the sum-product algorithm. These properties of LDPC code are …