Engineering Commons^™

Investigating Solutions To Wind Washing Issues In 2-Story Florida Homes; Phase 1, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Wind washing has been identified as a potentially significant issue regarding energy, demand, comfort, and humidity in some two-story Florida homes. In its most common configuration, wind washing occurs when attic spaces over first-floor portions of the home abut the second story, and the floor cavity of the second story is open to that attic space. Wind blowing into attic vents can push hot attic air into the inter-story floor cavity, bypassing the typical thermal boundaries of the building and introducing considerable heat into the house. Wind washing can also occur when there is little or no attic involved, where …

Method Of Transferring Strained Semiconductor Structure, Michael Nastasi

Department of Mechanical and Materials Engineering: Faculty Publications

The transfer of strained semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having surface contaminants. An interface that includes the contaminants if formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the deposited multilayer structure is bonded to a second substrate and is separated away at the interface, which results in transferring a multilayer structure from one substrate at least one strained semiconductor layer and at least one strain-induced seed layer. The strain-induced seed layer can be …

Self-Organized Nanolayers Of Organosilane Molecules, Ocelio V. Lima

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

There is a high degree of interest in organic thin films for lightweight, low power, rugged and flexible electronics. Conjugated organic molecules with polycyclic rings are being considered a major enabler of such applications. Due to a surface tension mismatch between the organic molecule with the inorganic support (mainly silicon oxides), molecular packing inside these thin films is often disordered, which suppresses the device performance. There are major efforts focused on modifying the bulk properties, for instance, maximizing orbital overlaps in the solid state, little attention was paid to receive long-range ordered thin films. A novel approach to afford conjugated …

Enhance Diamond Coating Adhesion By Oriented Interlayer Microcracking, Habio Guo, Xingcheng Xiao, Yue Qi, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

In this paper, we report a microcrack toughening mechanism for enhancing the adhesion of diamondcoating. The oriented microcracks were formed within the TiC interlayer to dissipate strain energy and accommodate deformation via the crack opening-closing mechanism, thus enhancing the coating/substrate interfacial toughness. The delamination of diamondcoating was effectively prevented when the parallel microcracks were confined within the interlayer and arrested at interfaces of coating/interlayer/substrate. Density functional theory calculations revealed that the highly anisotropicfracture strength of the TiC phase energetically favors crack initiation and propagation along (100) planes only, which are 54.7° away from the interface. These microcracks are constrained inside …

Optical Properties Of Semiconducting Boron Carbide For Neutron Detection Applications, Ravi B. Billa

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Solid state neutron detection devices based on semiconducting boron carbide have the potential for nearly ideal neutron detection effciency for thermal neutrons. The present work is focused on characterizing optical properties of this semiconducting boron carbide material as a step in further development of the material for neutron detection and other applications.

Semiconducting boron carbide films were grown on silicon substrates using plasma enhanced chemical vapor deposition and their optical properties were characterized using variable angle spectroscopic ellipsometry over a wide spectral range, from mid-infrared to vacuum-ultraviolet wavelengths. The effects of deposition substrate temperature and of post-deposition heat treatments on …

College Of Engineering Senior Design Competition Fall 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Each student in his or her senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. The senior design project encourages the student to use everything learned in the engineering program to create a practical, real-world solution to an engineering challenge.

A highlight of the year-long senior design project is the senior design competition. This competition, which usually takes place the week before finals each semester, helps focus the senior students on increasing the quality and potential for commercial application for their design projects.

Judges from local industry evaluate the projects on innovation, commercial …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Study Of Take-Up Velocity In Enhancing Tensile Properties Of Aligned Electrospun Nylon 6 Fibers, Johnny F. Najem

Mechanical Engineering Faculty Research

The variation of both the tensile properties and thermal properties of aligned electrospun fibers with the take-up velocity (TUV) of disc collector has not been widely investigated due to the difficulty of handling aligned nanofibers and measuring low loads. In this thesis, 25% of nylon 6 was dissolved in formic acid and then electrospun into fibers and the fibers were aligned using a rotating disc collector. We evaluated the tensile and thermal properties, average fiber diameter, crystallinity, crystalline morphology, molecular and crystalline orientation of aligned electrospun nylon 6 nanofibers as a function of TUV based on a disc collector. It …

A Biomechanical Comparison Of Polymethylmethacrylate-Reinforced And Expansive Pedicle Screws In Pedicle-Screw Revisions, Bora Bostan, Irfan Esenkaya, Taner Gunes, Mehmet Erdem, Murat Asci, Mehmet Halidun Kelestemur, Cengiz Sen

Faculty Publications - Mechanical Engineering

Objectives: Different techniques and choices exist for revision of pedicle screws, two of which are pedicle screw combined with cement augmentation and expansive pedicle screw fixation. This biomechanical study was designed to compare the pullout strengths of two different revision techniques. Methods: Fourteen lumbar vertebrae obtained from four calves (mean age 15 months) were divided into two groups equal in number. Monoaxial 6.0-mm pedicle screws were inserted into the right pedicles, and axial pullout testing was performed at a rate of 10 mm/min and failure strengths were recorded. Revision was performed with the same-sized pedicle screws reinforced with polymethyl-methacrylate in …

Nightcool: Nocturnal Radiation Cooling Concept, Long Term Performance Evaluation, Florida Solar Energy Center, John Sherwin

FSEC Energy Research Center®

An experimental evaluation has been conducted on a building-integrated night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling - largely during nighttime hours. Available house mass is used to store sensible cooling. The system's capability for solar dehumidification with minimal electricity input is demonstrated with long-term performance data taken over 2007 - 2009. A year-long study period …

Me-Em Enewsbrief, December 2009, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical Engineering-Engineering Mechanics eNewsBrief

No abstract provided.

Gender Dimorphic Acl Strain In Response To Combined Dynamic 3d Knee Joint Loading: Implications For Acl Injury Risk, Kiyonori Mizuno, Jack T. Andrish, Antonie J. Van Den Bogert, Scott G. Mclean

Mechanical Engineering Faculty Publications

While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as …

Thermodynamically Consistent Large Deformation Constitutive Model For Glassy Polymers, Ashwani Kumar Goel

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Polycarbonate(PC), like most glassy polymers when undergoing large deformations exhibits a very complex thermo-mechanical response. We look at PC as a model glassy polymer and examine its response to changes in loading rate, loading direction and temperature. We show that plastic flow in compression is accompanied by a change in the elastic response of PC from isotropic to anisotropic. This provides the necessity to introduce a new modeling method that can capture these changes. A finite deformation plasticity like thermodynamically consistent model is developed to capture this and the observed rate and temperature dependence. For this modeling method, we need …

Final Report: Space Coast Clean Cities Coalition Programmatic Support, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

This Final Report summarizes the work preformed by the Florida Solar Energy Center for U.S. Department of Energy for the National Clean Cities Program to reduce emissions and energy consumption of transportation vehicles. This report describes the activities and events of Florida Space Coast Clean Cities Coalition encompassing a nine county area in east central Florida. FSEC administers the Coalition and support the Coalition Board of Directors with meetings, workshop, reports, mailing list, membership, activities, questionnaires, fuel pricing, alternative vehicle and infrastructure deployment.

Device And Methods For Atomizing Fluids, Vedanth Srinivasan, Abraham J. Salazar, Kozo Saito, Richard Alloo, Sakakibara Masahito

Mechanical Engineering Faculty Patents

One embodiment of the invention is directed to an apparatus for atomizing a fluid. This apparatus includes an atomizing nozzle assembly. The atomizing nozzle assembly includes: a spray applicator enclosure having a fluid entry zone, a flow shape profiler region, a transducer, and a cavitation enhancer module, wherein the cavitation enhancer module includes a residence modulation zone and the residence modulation zone includes a backward facing step region. The apparatus is configured such that fluid can enter the fluid entry zone to the nozzle profiler, the transducer and the cavitation enhancer module. Other embodiments relate to methods for atomizing fluids.

Imprinting Polymerfilm On Patterned Substrate, Li Tan, Yen-Peng Kong, Stella W. Pang, Albert F. Yee

Department of Mechanical and Materials Engineering: Faculty Publications

A method of applying a pattern on a topography includes first applying a polymer film to an elastormer member, such as PDMS, to form a pad. The pad is then applied to a substrate having a varying topography under pressure. The polymer film is transferred to the substrate due to the plastic deformation of the polymer film under pressure compared to the elastic deformation of the PDMS member pulls away from the polymer layer, thereby depositing the polymer layer, thereby depositing the polymer layer upon the substrate.

Developing G-Rim And Participants Tests For Specific Commercial Programs For The Florida Natural Gas Association, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

The Florida Solar Energy Center performed an economic assessment for 7 common commercial appliances. This assessment calculates the gas rate impact measure and participants test score for selecting natural gas equipment over comparable electric equipment over a 20-year period. This type of analysis provides an indication whether or not the specific appliance program favors the end use customer and/or the utility company as economic beneficiaries. Given the project assumptions, all natural gas equipment types, with the exception of the pool heat pump water heater, show measures greater than 1 indicating that the natural gas appliance will have lower life-cycle costs …

Intermittent Behaviour Of A Cracked Rotor In The Resonance Region, Grzegorz Litak, Jerzy T. Sawicki

Mechanical Engineering Faculty Publications

Vibrations of the Jeffcott rotor are modelled by a three degree of freedom system including coupling between lateral and torsional modes. The crack in a rotating shaft of the rotor is introduced via time dependent stiffness with off-diagonal couplings. Applying the external torque to the system allows to observe the effect of crack “breathing” and gain insight into the system. It is manifested in the complex dynamic behaviour of the rotor in the region of internal resonance, showing a quasi-periodic motion or even non-periodic behaviour. In the present paper report, we show the system response to the external torque excitation …

Enhanced Vehicle Identification Utilizing Sensor Fusion And Statistical Algorithms, Stephane Roussel, Hemanth Porumamilla, Charles Birdsong, Peter Schuster, Christopher Clark

Mechanical Engineering

Several studies in the area of vehicle detection and identification involve the use of probabilistic analysis and sensor fusion. While several sensors utilized for identifying vehicle presence and proximity have been researched, their effectiveness in identifying vehicle types has remained inadequate. This study presents the utilization of an ultrasonic sensor coupled with a magnetic sensor and the development of statistical algorithms to overcome this limitation. Mathematical models of both the ultrasonic and magnetic sensors were constructed to first understand the intrinsic characteristics of the individual sensors and also to provide a means of simulating the performance of the combined sensor …

Optimization Of Three-Dimensional Branching Networks Of Microchannels For Thermal Management Of Microelectronics, Ricardo Ardila

FIU Electronic Theses and Dissertations

The aim of this work is to present a methodology to develop cost-effective thermal management solutions for microelectronic devices, capable of removing maximum amount of heat and delivering maximally uniform temperature distributions. The topological and geometrical characteristics of multiple-story three-dimensional branching networks of microchannels were developed using multi-objective optimization.

A conjugate heat transfer analysis software package and an automatic 3D microchannel network generator were developed and coupled with a modified version of a particle-swarm optimization algorithm with a goal of creating a design tool for 3D networks of optimized coolant flow passages. Numerical algorithms in the conjugate heat transfer solution …

Developing Natural Gas Cost Escalation Rates For The Associated Gas Distributors Of Florida, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) created a spreadsheet tool used to calculate the fuel escalation rates for electricity and natural gas for the previous 5-year and 10-year periods. These escalation rates are calculated at the local, State, and national level for both residential and commercial customers. The previous 5-year and 10-year general inflation rate as determined by the U.S. Department of Labor's Bureau of Labor Statistics consumer price index are also included. These calculations are made in accordance with rules established by the Florida Building Commission pursuant to rule 9B-13.0071, Cost Effectiveness of Amendments to Energy Code.

Modeling And Simulation Of Interactions Between Blast Waves And Structures For Blast Wave Mitigation, Wen Peng

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Explosions occur in military conflicts as well as in various industrial applications. Air blast waves generated by large explosions move outward with high velocity, pressure and temperature. The blast waves not only incapacitate military and civilian personnel, but also damages buildings, vehicles, and other properties. Hence, there has been extensive research on how to mitigate blast wave effects. Understanding the interactions between blast waves and structures is a very important step in the development of devices for blast wave mitigation. The objective of this dissertation is to explore the complicated physical problem of blast waves impacting structures. The structures comprise …

Mechanics-Based Analysis Of Selected Features Of The Exoskeletal Microstructure Of Popillia Japonica, Liang Cheng, Liyun Wang, Anette M. Karlsson

Mechanical Engineering Faculty Publications

We explore key mechanical responses of the layered microstructure found in selected parts of the exoskeletons (pronotum, leg and elytron) of Popillia japonica (Japanese beetle). Image analyses of exoskeleton cross-sections reveal four distinct layered regions. The load-bearing inner three regions (exocuticle, mesocuticle, and endocuticle) consist of multiple chitin-protein layers, in which chitin fibers align in parallel. The exocuticle and mesocuticle have a helicoidal structure, where the stacking sequence is characterized by a gradual rotation of the fiber orientation. The endocuticle has a pseudo-orthogonal structure, where two orthogonal layers are joined by a thin helicoidal region. The mechanics-based analyses suggest that, …

Evaluation Of Alternatives For Florida's 2010 Energy Code Update For Residential Buildings, Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

This report provides results of analysis of the Florida Energy Code (FEC) with respect to requirements of Florida House Bill 7135. The analysis uses Florida's performance-based code compliance software, EnergyGauge® USA, to conduct detailed analysis of H.B 7135 requirements to significantly increase the efficiency of new homes over time. First, results of an analysis of the long-term, year 2019 requirement for a 50% increase in new home energy efficiency are presented. Next, the 2009 edition of the International Energy Conservation Code (IECC) is analyzed with respect to the H.B. 7135 dual requirements that the 2009 IECC become the foundation code …

Methods And Devices For Cryopreservation Of Biological Cells And Tissues, Dayong Gao, Gary Van Zant, Xiangdong Cui

Mechanical Engineering Faculty Patents

Novel methods, compositions, and devices for achieving optimal cooling of living cells during cryopreservation are disclosed. In one aspect, the method comprises gradually cooling the cell to a first predetermined temperature, followed by rapidly cooling the cell to a second predetermined temperature. In another aspect, a device is described for achieving a desired cooling rate for a cell, comprising a first container for holding a cell, a second container for holding the first container, and optionally a frame for holding the first container in a spaced apart relationship with the second container. The method of the invention comprises placing cells …

Work In Progress - Role Of Faculty In Promoting Lifelong Learning, Jonathon Stolk, Susan M. Lord, Candice Stefanou, John Chen, Katharyn E. K. Nottis, Michael J. Prince

Mechanical Engineering

Students’ development of self-directed and lifelong learning capacities is vital for their success in today’s engineering environment. Instructors play a critical role in influencing outcomes related to self-directed learning (SDL) through their design of courses that support students’ transitions from controlled to autonomous learning behaviors. Yet there is a critical lack of research examining how instructor choices promote self-directed (and eventually lifelong) learning development in undergraduate engineering students. In this work in progress, we introduce a project that explores how instructor choices affect a range of student outcomes related to their development as self-directed and lifelong learners. Drawing on existing …

Clean Cities Annual Operating Plan 2009: Florida Space Coast Clean Cities Coalition, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

In March, 1997, the Florida Solar Energy Center (FSEC) joined the U.S. Department of Energy (DOE) Clean Cities program to form the Florida Space Coast Clean Cities Coalition in East Central Florida. Space Coast Coalition now consists of 10 counties, as the State is divided into eight Clean Cities regions. Florida Solar Energy Center is located in Cocoa in the approximate center of the coalition area. On October 1, 1999, the expanded Florida Space Coast Clean Cities Coalition was designated and authorized as the 75th Clean Cities Coalition. The Florida Space Coast Clean Cities Coalition is a 501-3c non-profit corporation …

Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009

Education and Outreach

No abstract provided.