Engineering Commons^™

Iov Mission Of A Mini-Hall Effect Thruster (Het), On-Board S-50 Micro-Satellite Class Platform, V. Stanzione, N. Melega, T. Misuri

Small Satellite Conference

SITAEL HT-100 Hall Effect Thruster (mini-HET) is one of the smallest and lowest power HET ever developed in Europe, whose performance and characteristics represent the state-of-the-art of this technology (power range between 140 and 300W, covering thrust levels from 5 to 15 mN). For HT-100 IOV purpose, SITAEL proposes to embark it (with relevant propulsion S/S built around) on its micro-platform (namely S-50, already used in the frame of ESA ESEO Project), which is a low cost/rapid development/qualified platform, ideal for IOD/IOV missions. A specific in-orbit validation mini-HET operative profile has been identified and acts as a main driver for …

Cubesat Handling Of Multisystem Precision Time Transfer, Nathan Barnwell, Watson Attai, Lucas Bassett-Audain, Maria Carrasquilla, John Chavez, Jon Dewald, Olivia Formoso, John Hanson, Belgacem Jaroux, Asia Nelson, Tyler Noel, Anh N. Nguyen, Seth Nydam, Ken Oyadomari, Jessie Pease, Cedric Priscal, Tyler Ritz, Steven Roberts, Paul Serra, Jan Stupl, Evan Waxman, Jasper Wolfe, John W. Conkin

Small Satellite Conference

No abstract provided.

Constellation Design Considerations For Smallsats, Andrew E. Turner

Small Satellite Conference

Design, implementation and operation of constellations using Smallsats are discussed. Due to the modest budgets allocated for these small spacecraft, economic considerations are paramount and optimal results must be obtained with a minimum number of spacecraft. Favorable orbits, preferably low Earth orbits (LEO) with minimum inclination, reduce launch cost and optimize Earth observation and communications, however mission requirements and/or rideshare opportunities may involve higher altitude and/or inclination. Candidate orbits including circular LEO with equatorial near-zero inclination, moderate inclination, polar and sun-synchronous inclinations are considered. The focus is on 600 km altitude since this lies within the regime currently used by …

Silicon Carbide Optical Telescopes In "Small Satellite" Constellations, Flemming Tinker, Chip Ragan, Alberto Bodden, Kevin Dahlberg

Small Satellite Conference

Optical telescopes are used in small satellites for imaging and laser applications serving markets such as earth resources, marine monitoring, communications and weather forecasting. Aluminum and glass are traditional materials used in telescope optical components but have mass and/or thermal properties that impact launch cost and on-station optical performance.

In constellation applications where a telescope is the primary payload, both the telescope and any required thermal mitigation mass becomes a large cost consideration due to its multiplication by the number of satellites launched and launch cost per kg. The use of alternate telescope materials that reduce mass and/or thermal sensitivity …

The Time For Scots Has Come, Johan Leijtens, Johan Uittenhout, Alexander Los, Torsten Vogel

Small Satellite Conference

With all major European primes starting to work on programs >100 satellites in 2015 the time for Space grade Commercial Off The Shelf components has come. For many years there have been discussions on costs savings by offering COTS components and especially the cubesat community knows several vendors that offer space systems in a COTS fashion. None of these component however qualify for the extreme requirements posed by the current constellations under design as most of them have to operate above 1000 km and are preferred to have a 10 to 15 year lifetime. This leads to several megarads of …

Design Of Cubesat Solar Panels Considering Acoustic Pressure, Devin Bunce, Erik Kroeker, Alex Ghosh, Victoria Coverstone

Small Satellite Conference

CubeSats are becoming increasingly complex. New innovative technology allows for more powerful computational capabilities and more complex science instruments. With strict mass requirements CubeSats need to cut weight from structural material as much as possible while maintaining mission integrity to maximize mass to electronics and instrumentation. Once in space the system is not under much stress and does not require much structural integrity; however, during launch the rocket produces a tremendous amount of sound, averaging around 160 dB in the local area. This acoustic pressure can crack solar cells if the array wall deflects too much.

The University of Illinois …

Magnetic Substance Disturbance Torque Caused By Shape Magnetic Anisotropy And Its Applications In Small-Sized Satellites, Takaya Inamori, Nobutada Sako, Ryu Funase, Shinichi Nakasuka

Small Satellite Conference

This study presents the magnetic substance disturbance torque caused by shape magnetic anisotropy. This magnetic substance disturbance occurs in on-board unsymmetrical magnetic substances, even if the magnetic substance does not have a residual magnetic dipole moment. Although this magnetic substance disturbance torques has not been considered in previous small-sized satellites, in some cases, the strength of the disturbance is stronger than the effect of aerodynamic and solar radiation disturbances. First, this study presents the strength and effects of the magnetic substance disturbance torque in Cubesat satellites: XI-IV and PRISM in the University of Tokyo. Then, the study shows that the …

Nitesat: A People-Powered Science Mission, Ken Walczak

Small Satellite Conference

The Far Horizons space program at the Adler Planetarium is designing, building, and will operate NITESat (Night Imaging and Tracking Experiment Satellite), a 2U CubeSat mission supported by a robust education and public outreach effort. The primary science mission of NITESat is to capture high-resolution, three-color, nighttime imagery of the Midwestern United States to quantify and characterize the nature and intensity of light pollution across the region. The motto of the Adler Planetarium is “Join Us In Exploring Space,” and the NITESat mission firmly embraces this concept with students, interns, and volunteers embedded in every stage of the design, build …

The Role Of Emulation In Constellations Of Small Satellites, Randy Culver

Small Satellite Conference

Small satellites have become mainstream. New ventures are deploying constellations of small satellites that are being networked to perform remote sensing, image collection, and internet routing. This paper describes how a scalable, system-level emulation plays a key role when fielding and flying a new constellation of small satellites.

It's an understatement to say that designing, implementing, and validating a system employing a dozen, a hundred, or a thousand satellites is complex. There's inherent risk "scaling up" the number of deployed small satellites from few to many. Engineering analysis and testing cannot be deferred until there's a full constellation in orbit. …

Performance Of Dynamically Simulated Reference Patterns For Cross Correlation Ebsd, Brian Jackson, Jordan Christensen, Saransh Singh, Marc De Graef, David T. Fullwood, Eric Richards Homer, Robert Wagoner

Faculty Publications

High-resolution (or \cross-correlation") electron backscatter diffraction analysis (HR-EBSD) utilizes cross-correlation techniques to determine relative orientation and distortion of an experimental electron backscatter diffraction pattern (EBSP) with respect to a reference pattern. The integrity of absolute strain and tetragonality measurements of a standard Si/SiGe material have previously been analyzed using reference patterns produced by kinematical simulation. While the results were promising, the noise levels were significantly higher for kinematically produced patterns, compared to real patterns taken from the Si region of the sample. This paper applies HR-EBSD techniques to analyze lattice distortion in a Si/SiGe sample, using recently developed dynamically simulated …

Building A Pathway To Engineering For Our Daughters – Brick By Brick, Ali P. Gordon

UCF Forum

As a father of young elementary and middle school-aged kids, I’m also curious to know exactly how my undergrad students came to be interested in mechanical engineering. An exchange with a UCF student might go like this: “You did a great job on the exam. Congrats! By the way, how did you get interested in mechanical engineering, anyway?” I mentally log the answers for my kids’ future benefit.

A Hybrid Technique Of Energy Harvesting From Mechanical Vibration And Ambient Illumination, M Shafiqur Rahman

LSU New Orleans Theses and Dissertations

Hybrid energy harvesting is a concept applied for improving the performance of the conventional stand-alone energy harvesters. The thesis presents the analytical formulations and characterization of a hybrid energy harvester that incorporates photovoltaic, piezoelectric, electromagnetic, and electrostatic mechanisms. The initial voltage required for electrostatic mechanism is obtained by the photovoltaic technique. Other mechanisms are embedded into a bimorph piezoelectric cantilever beam having a tip magnet and two sets of comb electrodes on two sides of its substructure. All the segments are interconnected by an electric circuit to generate combined output when subjected to vibration and solar illumination. Results for power …

Sustainable Ambient Air Quality Monitoring System, Poojitha Aleti

LSU New Orleans Theses and Dissertations

Deterioration of air quality is a growing concern in the world. Air pollution causes serious health problems and also can sometimes result in death. In order to assess air quality, long term and continuous monitoring of pollutant levels in ambient air are needed, such monitoring is often expensive, cumbersome, and resource intensive and so the monitoring programs often fail to succeed.

This research focused on designing an ambient air monitoring system by integrating (1) low-cost sensor with a battery, (2) repurposed materials to fabricate all-weather housing for air monitors, and (3) electronics needed to download the data to an on-site …

Spice: A Software Tool For Studying End-User’S Insecure Cyber Behavior And Personality-Traits, Anjila Tamrakar

LSU New Orleans Theses and Dissertations

Insecure cyber behavior of end users may expose their computers to cyber-attack. A first step to improve their cyber behavior is to identify their tendency toward insecure cyber behavior. Unfortunately, not much work has been done in this area. In particular, the relationship between end users cyber behavior and their personality traits is much less explored. This paper presents a comprehensive review of a newly developed, easily configurable, and flexible software SPICE for psychologist and cognitive scientists to study personality traits and insecure cyber behavior of end users. The software utilizes well-established cognitive methods (such as dot-probe) to identify number …

Experimental Study And Numerical Simulation Of Methane Oxygen Combustion Inside A Low Pressure Rocket Motor, Mine Kaya

LSU New Orleans Theses and Dissertations

In this thesis, combustion processes in a laboratory-scale methane based low pressure rocket motor (LPRM) is studied experimentally and numerically. Experiments are conducted to measure flame temperatures and chamber temperature and pressure. Single reaction-four species reacting flow of gaseous methane and gaseous oxygen in the combustion chamber is also simulated numerically using a commercial CFD solver based on 2-D, steady-state, viscous, turbulent and compressible flow assumptions. LPRM geometry is simplified to several configurations, i.e. Channel and Combustion Chamber with Nozzle and FWD. Flow in a Bunsen burner is simulated inside Channel geometry in order to validate the reaction model. Grid …

Effects Of Build Parameters On Compression Properties For Ultem 9085 Parts By Fused Deposition Modeling, Krishna P. Motaparti, Gregory Taylor, Ming-Chuan Leu, K. Chandrashekhara, James Castle, Mike Matlack

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It has been observed by various researchers that parts fabricated by the Fused Deposition Modeling (FDM) process have anisotropic properties. The research presented in the present paper was aimed to study the compression properties of FDM parts and to comprehend their dependence on build parameters. In this study Ultem 9085 was used as the material to fabricate both solid and sparse-build coupons with variations in build direction, raster angle and air gap. A full factorial experimental design was used to study the individual and combined effects of these build parameters on the mechanical properties of the coupons. The mechanical properties …

Properties Of Partially Stabilized Zirconia Components Fabricated By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Ming-Chuan Leu, Greg Hilmas, Jeremy Lee Watts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Ceramic On-Demand Extrusion (CODE) process is a novel additive manufacturing process for fabricating dense ceramic components from aqueous pastes of high solids loading. In this study, 3 mol% Y₂O₃ stabilized tetragonal zirconia polycrystal (3Y-TZP) parts were fabricated using the CODE process. The parts were then dried in a humidity controlled environmental chamber and sintered under atmospheric pressure. Mechanical properties of the sintered parts were examined using ASTM standard test techniques, including density, Young’s modulus, flexural strength, Weibull modulus, fracture toughness and Vickers hardness. The microstructure was analyzed, and grain size was measured using scanning electron microscopy. …

3d Printing Of A Polymer Bioactive Glass Composite For Bone Repair, Caroline Murphy, Krishna C. R. Kolan, M. Long, Ming-Chuan Leu, Julie A. Semon, D. E. Day

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A major limitation of synthetic bone repair is insufficient vascularization of the interior region of the scaffold. In this study, we investigated the 3D printing of adipose derived mesenchymal stem cells (AD-MSCs) with polycaprolactone (PCL)/bioactive glass composite in a single process. This offered a three-dimensional environment for complex and dynamic interactions that govern the cell’s behavior in vivo. Borate based bioactive (13-93B3) glass of different concentrations (10 to 50 weight %) was added to a mixture of PCL and organic solvent to make an extrudable paste. AD-MSCs suspended in Matrigel was extruded as droplets using a second syringe. Scaffolds measuring …

Selective Laser Sintering Of Low Density, Low Coefficient Of Thermal Expansion Silica Parts, John M. Hostetler, Jonathan T. Goldstein, Augustine M. Urbas, Rodrigo E. Gutierrez, Theresa E. Bender, Charles S. Wojnar, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a study of selective laser sintering of silica-gel. The objective of this work is to investigate a technique to create free-form, low to zero coefficient of thermal expansion structures. This offers potential cost savings over the conventional casting of large pieces of glass-ceramic followed by machining lightening features. In this paper, A CO₂ laser is coupled through a gantry system and focused onto a binder-free silica-gel powder bed (15-40 μm particles). Prior to writing each layer, powder is dispensed by sifting it onto the build platform as opposed to a conventional wiper system. This avoids contacting …

Laser Line Scan Characterization Of Geometric Profiles In Laser Metal Deposition, Michelle L. Gegel, A. Nisbett, Douglas A. Bristow, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser Metal Deposition (LMD) is an additive manufacturing process in which material is deposited by blowing powdered metal into a melt pool formed by a laser beam. When fabricating parts, the substrate is subjected to motion control such that the melt pool traces a prescribed path to form each part layer. Advantages of LMD include relatively efficient powder usage, the ability to create functionally-graded parts and the ability to repair high-value parts. The process, however, is sensitive to variations in process parameters and a need for feedback measurements and closed-loop control has been recognized in the literature [1, 2]. To …

A Smooth Toolpath Generation Method For Laser Metal Deposition, Renwei Liu, Zhiyuan Wang, Yunlu Zhang, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser metal deposition (LMD), also known as direct metal deposition (DMD) or laser engineered net shaping (LENS), which uses a laser beam to form a melt pool on a metallic substrate, into which powder or wire is fed. The conventional contour and zigzag toolpath pattern for LMD are discontinuous at turn points or corner points. The discontinuous toolpath causes uneven deposition, which brings height variation and porosity problems. This paper aims to develop a smooth toolpath generation method for LMD to improve the deposition quality. A parametric curve equation based on trigonometric functions is derived and built. It can be …

Powders For Additive Manufacturing Processes: Characterization Techniques And Effects On Part Properties, Austin T. Sutton, Caitlin S. Kriewall, Ming-Chuan Leu, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Powder-bed based Additive Manufacturing is a class of Additive Manufacturing (AM) processes that bond successive layers of powder by laser melting to facilitate the creation of parts with complex geometries. As AM technology transitions from the fabrication of prototypes to end-use parts, the understanding of the powder properties needed to reliably produce parts of acceptable quality becomes critical. Consequently, this has led to the use of powder characterization techniques such as scanning electron microscopy (SEM), laser light diffraction, x-ray photoelectron spectroscopy (XPS), and differential thermal analysis (DTA) to both qualitatively and quantitatively study the effect of powder characteristics on part …

Analysis Of Optimization Methods In Multisteerable Filter Design, Philip Zanco

LSU New Orleans Theses and Dissertations

The purpose of this thesis is to study and investigate a practical and efficient implementation of corner orientation detection using multisteerable filters. First, practical theory involved in applying multisteerable filters for corner orientation estimation is presented. Methods to improve the efficiency with which multisteerable corner filters are applied to images are investigated and presented. Prior research in this area presented an optimization equation for determining the best match of corner orientations in images; however, little research has been done on optimization techniques to solve this equation. Optimization techniques to find the maximum response of a similarity function to determine how …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• College Convocation 2016

Bubble Formation In Additive Manufacturing Of Borosilicate Glass, Junjie Luo, Theresa Bender, Douglas A. Bristow, Robert G. Landers, Jonathan T. Goldstein, Augustine M. Urbas, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Entrapped bubbles are an important problem in conventional glass manufacturing. It is also a significant factor determining the quality of glass products produced using additive manufacturing (AM). This paper reports on the bubble formation and entrapment in filament-fed AM printing of borosilicate glass. This process involves maintaining a local molten region using a CO₂ laser. A 2 mm filament is fed continuously into the molten region while CNC stages position the workpiece relative to the laser and filament feed. Two different bubble regimes are identified in experiments with borosilicate glass. These regimes can be related to different physical phenomena, …

Integration Of Voxel Based And Source Based Representation For Computer Aided Design Of Functional Gradient Materials, Fangquan Wang, Frank W. Liou, Todd E. Sparks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Functionally Gradient Materials (FGMs) feature smooth transition from one material to another within a single object. FGMs modeling is considered to be one of the new challenges in Computer Aided Design area. To overcome this challenge, this paper presents the integration of a source-based and voxel-based approach to model FGMs. The input of STL format can be meshed and voxelized. The material composition and material varying information in each voxel can be generated from control sources. In addition, surface source is used to define default material information, and several filtering methods, including Gaussian filter, Average filter, are applied to blend …

Designed Extrudate For Additive Manufacturing Of Zirconium Diboride By Ceramic On-Demand Extrusion, Devin Mcmillen, Wenbin Li, Ming-Chuan Leu, Greg Hilmas, Jeremy Lee Watts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work describes a process by which zirconium diboride (ZrB2) parts may be fabricated using the Ceramic On-Demand Extrusion (CODE) process. An oxide-carbide-nitride system consisting of ceramic powders and pre-ceramic organics, designed to yield ZrB₂ after reaction sintering, has been developed to produce an aqueous-based extrudate for subsequent processing in the CODE system. Pressurelessly sintered test specimens containing 1 wt% PVA binder achieve high relative density ≥ 99%. The viscoelastic response of the extrudate was characterized via spindle rheometry with a small sample adapter. Batches with 1 wt% PVA and 0.5 wt% Methocel show strong shear thinning characteristic, under …

A Novel Extrusion-Based Additive Manufacturing Process For Ceramic Parts, Amir Ghazanfari, Wenbin Li, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An extrusion-based additive manufacturing process, called the Ceramic On-Demand Extrusion (CODE) process, for producing three-dimensional ceramic components with near theoretical density is introduced in this paper. In this process, an aqueous paste of ceramic particles with a very low binder content ( < 1 vol%) is extruded through a moving nozzle at room temperature. After a layer is deposited, it is surrounded by oil (to a level just below the top surface of most recent layer) to preclude non-uniform evaporation from the sides. Infrared radiation is then used to partially, and uniformly, dry the just-deposited layer so that the yield stress of the paste increases and the part maintains its shape. The same procedure is repeated for every layer until part fabrication is completed. Several sample parts for various applications were produced using this process and their properties were obtained. The results indicate that the proposed method enables fabrication of large, dense ceramic parts with complex geometries.

The Quanta Image Sensor: Every Photon Counts, Eric Fossum, Jiaju Ma, Saleh Masoodian, Leo Anzagira, Rachel Zizza

Dartmouth Scholarship

The Quanta Image Sensor (QIS) was conceived when contemplating shrinking pixel sizes and storage capacities, and the steady increase in digital processing power. In the single-bit QIS, the output of each field is a binary bit plane, where each bit represents the presence or absence of at least one photoelectron in a photodetector. A series of bit planes is generated through high-speed readout, and a kernel or “cubicle” of bits (x, y, t) is used to create a single output image pixel. The size of the cubicle can be adjusted post-acquisition to optimize image quality. The specialized sub-diffraction-limit photodetectors in …

Simulation Of Cooling Rate Effects On Ti-48al-2cr-2nb Crack Formation In Direct Laser Deposition, Lei Yan, Wei Li, Xueyang Chen, Yunlu Zhang, Joseph William Newkirk, Frank W. Liou, David Dietrich

Materials Science and Engineering Faculty Research & Creative Works

Transient temperature history is vital in direct laser deposition (DLD) because it reveals the cooling rate at specific temperatures, which directly relates to phase transformation and types of microstructure formed in deposit. FEA simulation was employed to study the transient temperature history and cooling rate at different experimental setups in Ti-48Al-2Cr-2Nb DLD process. In this paper, an innovative model was described, which combines a moving Gaussian distribution heat source and element birth and death technology in ANSYS, help to analysis cooling rate control method and guide crack-free deposits build process.