Engineering Commons^™

Structural Integrity Assessment Of Tufted Textile Composite And Its Comparison With Laminated Textile Composite, A Saboktakin, A Ghasemi, H Mohammadi

Journal of Metals, Materials and Minerals

Three dimensional composites have been used in aerospace industry to improve interlaminar strength. This paper evaluates the 3D tufted composites from aspect of their mechanical properties. The tufted composite panel was manufactured based on polyester resin as well as an untufted laminated composite for comparison purposes. Experiments show that specimens with transverse tufting suffer slighter reduction in the tensile strength than longitudinal tufting. The tufted composites are found lower tensile strength compared with laminated composite samples accompanied with slight improvement in the compression strength and high strain rate tensile strength. The experimental results presented in this paper should be valuable …

Thermal Correction Judd-Ofelt Analyze Of Eu3+ Ion Doped Calcium Gadolinium Silicoborate Oxyfluoride Glass, N Wantana, Y Ruangtaweep, J Kaewkhao

Journal of Metals, Materials and Minerals

The Calcium Gadolinium Silicoborate Oxyfluoride glass doped with 1.0 mol% of Eu3+ concentration. (CaGdSiBF:Eu3+) was prepared by a melt quenching technique for study in the absorption and emission properties. Glass absorbed photon in ultraviolet, visible light and near infrared regions. The excitation with 275 nm of Gd3+ show the strongest red emission at 613 nm from 5D0→7F2 transition. The Judd-Ofelt (J-O) intensity parameters are derived from the integrated area under absorption and emission, including the refractive index. The thermal correction was used to improve J-O analysis from an uncertainty of Eu3+ population on the ground state. The spectroscopic results were …

Methyl Methacrylate Magnetic Molecularly Imprinted Polymer For Gluten Determination, D Limthin, K Chattrairat, P Leepheng, S Wisutthipat, P Gansa, A Klamchuen, D Phromyothin

Journal of Metals, Materials and Minerals

The gluten protein is found in some rice and flour. The allergy of gluten, a little bit of gluten in diet cause long-term damage and dangerous to the body. Even tiny amounts of gluten in diet may bring enormous symptoms. The rapid and simple method for gluten detection is molecularly imprinted polymers (MIP) combined with electrochemical analysis. In addition, magnetic molecularly imprinted polymers (MMIP) as known as Fe3O4 magnetic nanoparticles have used in combination with electrochemical measurement as well to improve the sensitivity of detection. In this work, the MMIP was combined with electrochemical technique. The Fe3O4 magnetic nanoparticles were …

Effects Of Sulfur Vulcanization System On Cure Characteristics, Physical Properties And Thermal Aging Of Epoxidized Natural Rubber, A Larpkasemsek, L Raksaksri, S Chuayjuljit, P Chaiwutthinan, A Boonmahitthisud

Journal of Metals, Materials and Minerals

The epoxidized natural rubber (ENR) with 40 mol% epoxidation (ENR-40) was initially prepared via 'in situ' epoxidation of concentrated natural rubber latex with formic acid (1M to isoprene unit) and hydrogen peroxide (0.75 M to isoprene unit) at 50ºC for 8 h. The as-prepared ENR-40 was then cured with three different sulfur vulcanization/curing systems, including conventional (CV), semi-efficiency (semi-EV) and efficiency (EV) systems using tetrabenzylthiuram disulphide (TBzTD) as a non-carcinogenic accelerator on a compression molding machine. The effects of sulfur to accelerator ratio on the cure characteristics, tensile properties (tensile strength, modulus at 300% strain (M300) and elongation at break), …

Investigation On The Tribological Characteristics Of Lubricated Al2o3-Tic (Altic) Surface, S Jitphayomkun, P Dechadilok, D Tungasmita, S Tungasmita

Journal of Metals, Materials and Minerals

Lapping process is one of the most important processes in modern hard disk drive manufacturing. Using lubricant in the lapping process does not only reduce the friction but also transfers heat and captures debris away from the surface contacts. The effects of tribological parameters on the lubricant characteristics and friction regime were investigated, using tribometer. The tribological behaviors of the lubricated alumine-titanium carbide (AlTiC) surface with different types of lubricants were also investigated. The coefficient of friction values of stainless steel ball sliding on the lubricated surface exhibited much lower than dry surface. The variation of normal force and sliding …

Recovery Of Recycled Poly(Ethylene Terephthalate) Via Melt Mixing With Poly(Butylene Succinate) And Ultrafine Wollastonite, P Chaiwutthinan, S Chuayjuljit, A Boonmahitthisud, A Larpkasemsuk

Journal of Metals, Materials and Minerals

Recycled poly(ethylene terephthalate) (R-PET) flakes obtained from postconsumer bottles were melt mixed with poly(butylene succinate) (PBS) or with PBS plus ultrafine wollastonite (2000 mesh) at various compositions on a twin screw extruder, followed by injection molding. The tensile properties, morphology, thermal stability and limiting oxygen index (LOI) of the resulting blends and composites were evaluated. Among the investigated R-PET/PBS blend compositions (20, 30, 40, 50, and 60 wt% PBS), the 60/40 wt% blend exhibited the highest tensile strength and elongation at break, but a lower tensile modulus and thermal stability compared to those of the neat R-PET. This blend was …

First Approach To Coupling Of Numerical Lifting-Line Theory And Linear Covariance Analysis For Uav State Uncertainty Propagation, Cory D. Goates, Randall S. Christensen, Robert C. Leishman

Faculty Publications

Numerical lifting-line is a computationally efficient method for calculating aerodynamic forces and moments on aircraft. However, its potential has yet to be tapped for use in guidance, navigation, and control (GN&C). Linear covariance analysis is becoming a popular GN&C design tool and shows promise for pairing with numerical lifting-line. Pairing numerical lifting-line with linear covariance analysis allows for forward propagation of state uncertainty for real-time decision making. We demonstrate this for select state variables in a drone aerial recapture situation. Linear covariance analysis uses finite difference derivatives obtained from numerical lifting-line to calculate force and moment variances. These show agreement …

Stochastic Resonance Enables Bpp/Log∗ Complexity And Universal Approximation In Analog Recurrent Neural Networks, Emmett Redd, A. Steven Younger, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Stochastic resonance (SR) is a natural process that without limit increases the precision of signal measurements in biological and physical sciences. Most artificial neural networks (NNs) are implemented on digital computers of fixed precision. A NN accessing universal approximation and a computational complexity class more powerful that of a Turing machine needs analog signals utilizing SR's limitless precision increase. This paper links an analog recurrent (AR) NN theorem, SR, BPP/log∗ (a physically realizable, super-Turing computation class), and universal approximation so NNs following them can be made computationally more powerful. An optical neural network mimicking chaos indicates super-Turing computation has been …

Recurrent Network And Multi-Arm Bandit Methods For Multi-Task Learning Without Task Specification, Thy Nguyen, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper addresses the problem of multi-task learning (MTL) in settings where the task assignment is not known. We propose two mechanisms for the problem of inference of task's parameter without task specification: parameter adaptation and parameter selection methods. In parameter adaptation, the model's parameter is iteratively updated using a recurrent neural network (RNN) learner as the mechanism to adapt to different tasks. For the parameter selection model, a parameter matrix is learned beforehand with the task known apriori. During testing, a bandit algorithm is utilized to determine the appropriate parameter vector for the model on the fly. We explored …

Genotype Combinations Linked To Phenotype Subgroups In Autism Spectrum Disorders, Junya Zhao, Thy Nguyen, Jonathan Kopel, Perry B. Koob, Donald A. Adieroh, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates a computational model that allows for systematic comparison of phenotype data with genotype (Single Nucleotide Polymorphisms (SNPs)) data based on machine learning techniques to identify discriminant genotype markers associated with the phenotypic subgroups. The proposed discriminant SNP identifier model is empirically evaluated using Autism Spectrum Disorder (ASD) simplex sample. Six phenotype markers were selected to cluster the sample in a hexagonal lattice format yielding five multidimensional subgroups based on extremities of the phenotype markers. The SNP selection model includes random subspace selection of SNPs in conjunction with feature selection algorithms to determine which set of SNPs were …

Nuclear Engineering At The Air Force Institute Of Technology: A Unique Graduate School Experience For A Unique Set Of Students, Michael B. Shattan

Faculty Publications

In August 2018, the Air University Commander formed a task force to review the Air Force’s Science, Technology, Engineering, and Mathematics (STEM) graduate education programs that are delivered and administered through the Air Force Institute of Technology (AFIT). The study was rooted in strategies to support the 2018 National Defense Strategy, and provided the necessary technologically equipped personnel for the 21st century. The study was commonly referred to as “reimagining AFIT”. Several themes emerged from the study, which include reaching a broader community of Airmen through alternate educational modes (e.g. distance learning, short course etc.), forming strategic educational and research …

Analysis Of Sea Clutter Using Dynamic Mode Decomposition, Yanming Zhang, Lijun Jiang, Hong Tat Ewe

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel method based on a dynamic mode decomposition (DMD) for sea clutter analysis is proposed. It extracts the temporal patterns and corresponding dynamic modes from the sea clutter simultaneously. Moreover, the temporal patterns display similar properties with traditional analysis using Doppler spectrum. The corresponding dynamic modes represent the cardinal feature within the sea clutter. To demonstrate the effectiveness of the proposed method, the measured sea clutter data collected by IPIX radar is analyzed. It is shown that DMD spectrum has the same frequency-shift and similar amplitude with the Doppler Spectrum. In addition, the Probability Density Function …

A Novel Data-Driven Analysis Method For Nonlinear Electromagnetic Radiations Based On Dynamic Mode Decomposition, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Nonlinear effects generated in complex electronic systems such as cell phones and computers cause broadband electromagnetic radiations. They are very difficult to model but could be key contributors to the radiated spurious emission (RSE) and radio frequency interference (RFI). In this paper, a novel data-driven characterization method is proposed to analyze the transient responses of the nonlinear circuits and their nonlinear electromagnetic radiations. It employs the dynamic mode decomposition (DMD) to simultaneously extract the temporal patterns and their corresponding dynamic modes. The temporal patterns show high order harmonics generated by the nonlinearity. Then these temporal spatial coherent patterns could provide …

Distributed State Estimation By Using Active-Passive Sensor Networks, Akhilesh Raj, S. Jagannathan, Tansel Yucelen

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel adaptive observer for heterogeneous sensor networks (HSNs) to estimate state vector of an unknown target or process by using the sensed output when the input to the target/process is also not known. In an HSN, nodes are considered either active or passive depending upon their ability to sense the target output. The local information exchange among the nodes is dictated by a connected graph. By using the criterion of collective observability, a novel distributed adaptive estimation is introduced where the nodes are allowed to have different sensor modalities. Stability analysis shows uniform ultimate boundedness of …

The Potentiality Of Space Enterprise Force Reconstitution: Nationalizing Civilian Satellites During Kinetic Conflicts, Robert A. Bettinger, Sara Schmitt

Faculty Publications

This article will discuss the possibility of employing a policy of civilian satellite nationalization during a space war as a means of US Space Enterprise force re- constitution to ensure continued access to space capabilities necessary for the execution of the national strategy, as well as deterring potential adversaries from initiating counterspace hostilities. In terms of structure, the authors will examine the thesis by answering these questions. First, what historical precedent exists for the rapid military acquisition of civilian assets via nationalization? Second (given the unique nature of space as an operational environment), can that historical precedent be applied to …

M2 Factor Of A Vector Schell-Model Beam, Milo W. Hyde Iv, Mark F. Spencer

Faculty Publications

Extending existing scalar Schell-model source work, we derive the M² factor for a general electromagnetic or vector Schell-model source to assess beam quality. In particular, we compute the M² factors for two vector Schell-model sources found in the literature. We then describe how to synthesize vector Schell-model beams in terms of specified, desired M² and present Monte Carlo simulation results to validate our analysis.

Distributed Fiber-Optic Pressure Sensor Based On Bourdon Tubes Metered By Optical Frequency-Domain Reflectometry, Chen Zhu, Yiyang Zhuang, Yizhen Chen, Rex E. Gerald Ii, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

We report a distributed fiber-optic pressure sensor based on Bourdon tubes using Rayleigh backscattering metered by optical frequency-domain reflectometry (OFDR). In the proposed sensor, a piece of single-mode fiber (SMF) is attached to the concave surfaces of Bourdon tubes using a thin layer of epoxy. The strain profiles along the concave surface of the Bourdon tube vary with applied pressure, and the strain variations are transferred to the attached SMF through the epoxy layer, resulting in spectral shifts in the local Rayleigh backscattering signals. By monitoring the local spectral shifts of the OFDR system, the pressure applied to the Bourdon …

Bioproduction Of Adipic Acid Using Engineered Pseudomonas Putida Kt2440 From Lignin-Derived Aromatics, Howard Willett

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Current industrial synthesis of adipic acid is nonrenewable and depends on a carcinogenic starting material, benzene. Biocatalysis with an engineered microorganism could turn a renewable feedstock into a value-added chemical such as adipic acid. Here we engineered P. putida KT2440 to transform lignin-derived aromatics, coumarate and ferulate, into adipic acid. Lignin is a recalcitrant plant biopolymer burned for thermal energy. Conversion of lignin into a value-added chemical will improve the efficiency of lignocellulose processing plants. The best performing engineered KT2440 strain produces 2.52 mM adipate at a 9.5% (mole/mole) yield. This was achieved by the genetic insertion of non-natural biosynthetic …

Economic Model Predictive Control And Process Equipment: Control-Induced Thermal Stress In A Pipe, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Recent work on economic model predictive control (EMPC) has indicated that some processes may be operated in a more economically-optimal fashion under a time-varying operating policy than under a steady-state operating policy. However, a concern for time-varying operation is how such a change in operating policy might impact the equipment within which the processes being controlled are carried out. While under steady-state operation, the operating conditions to which equipment would regularly be exposed can be estimated, this would be more difficult to assess thoroughly a priori under time-varying operation. It could be explored whether the EMPC could be made aware …

Active-Passive Dynamic Consensus Filters For Linear Time-Invariant Multiagent Systems, J. Daniel Peterson, Tansel Yucelen, S. Jagannathan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Active-passive dynamic consensus filters consist of a group of agents, where a subset of these agents is able to observe a quantity of interest (i.e. active agents) and the rest are subject to no observations (i.e. passive agents). Specifically, the objective of these filters is that the states of all agents are required to converge to the weighted average of the set of observations sensed by the active agents. Existing active-passive dynamic consensus filters in the classical sense assume that all agents can be modeled as having single integrator dynamics, which may not always hold in practice. Motivating from this …

Stabilization Of Homoclinic Orbits Of Two Degree-Of-Freedom Underactuated Systems, Nilay Kant, Ranjan Mukherjee, Hassan K. Khalil

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A hybrid controller for stabilization of homoclinic orbits of two degree-of-freedom (DOF) underactuated systems is proposed. The controller is comprised of continuous-time inputs, impulsive brakings, and virtual impulsive inputs for resetting of the passive coordinate. Impulsive brakings of the active coordinate result in instantaneous negative changes in the mechanical energy of the system. An impulsive dynamical system framework is adopted for modeling the hybrid dynamics and a Lyapunov function is defined for stabilization of the orbit. Sufficient conditions for stabilization are presented such that the Lyapunov function decreases monotonically under the action of the continuous inputs and undergoes negative jumps …

Safety Analysis For Shift Implementation, Reginald R. Souleyrette, Riana Tanzen, William Nicholas Staats, Eric R. Green, Mei Chen

Kentucky Transportation Center Research Report

The Strategic Highway Investment Formula for Tomorrow (SHIFT) program research team evaluated the program’s 2018 safety component and developed a new methodology to rank the safety needs of 2020 projects. For the current year, the research team suggests replacing the SHIFT 2018 formulas (based on three naive crash measures) with a new metric, Excess Expected Crashes, formulated from the most current safety analysis guidelines available in the Highway Safety Manual. In addition, the research team developed a user-friendly network screening tool serving as a method to prioritize projects. Another automation tool was developed that will help safety professionals evaluate and …

A Study To Determine How To Measure The Laser Safety Climate At Academic Institutions, John Settlemyer

OTS Master's Level Projects & Papers

Statement of Problem

The purpose of this study was to determine if the laser safety climate can be measured at academic institutions and what factors would provide valid measures of the laser safety climate at academic institutions. Specifically, the study attempted to answer the following questions:

Research Questions

RQ1. Can laser safety climate be measured at academic institutions using a climate survey instrument?

RQ2. What factors should be measured by a laser safety climate instrument?

RQ3. What measures would provide actionable data for prescriptive intervention by laser safety professionals at academic institutions? (p. 4)

Tailoring Cell-Material Interactions Via Poly(Acrylic Acid) Brushes To Enhance Nonviral Substrate-Mediated Gene Delivery, Amy Mantz

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Nonviral gene delivery modifies gene expression by transferring exogenous genetic material into cells and tissues, typically through a bolus of complexes formed by electrostatic interactions between cationic lipid or polymer vectors with negatively charged nucleic acids (e.g. DNA). Although nonviral gene delivery is safer, more cost-effective, and more flexible compared to viral systems, nonviral transfection suffers from low efficiency due to extracellular and intracellular barriers. Much research has focused on tuning physiochemical properties of the complexing vectors to improve transfection, yet the cell-material interface may prove a better platform to immobilize DNA complexes for substrate-mediated delivery (SMD) and modulate the …

Impedance Mismatch Effects In Microstrip And Stripline Ebg Common-Mode Filters, Marina Y. Koledintseva, Sergiu Radu, Joe Nuebel

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, impedance mismatch effects on the characteristics of common-mode (CM) electromagnetic bandgap (EBG) filters are studied using 3D full-wave numerical simulations. Herein, the terminations are fixed at 50 Ohms, and the effect of the differential line impedance variations are studied. Two types of CM EBG filters are considered in this work, both are designed using standard printed circuit board technology. The first group contains microstrip (MS) differential pairs running above the EBG plane, and the second group contains strip line (SL) differential pairs running on one of the layers next to the EBG plane. It is shown that …

Travel Behaviors Of Persons With Intellectual And Developmental Disabilities, Joseph C. Totten

Civil and Environmental Engineering Master's Project Reports

People with intellectual and developmental disabilities live different lives than the general population. Often prohibited from driving, persons with intellectual disabilities cite transportation as top concern, limiting their independence and freedom to live, work or recreate where and when they choose. Improving services for persons with developmental disabilities requires that engineers and planners understand how persons with intellectual disabilities travel, and what types of transportation are available to them. This report hopes to identify the availability of transportation options to persons with developmental disabilities such that planners, engineers and advocates can determine how altering the transportation system might affect persons’ …

Test Setup Design And Cyclic Evaluation Of Rocking Clt Wall And Floor Restoring Force Lateral System, Aaron Davis Smith

Civil and Environmental Engineering Master's Project Reports

The introduction of the demand for mass timber buildings in areas with seismic hazards has called for new lateral systems. Lateral systems in mass timber building typically utilize a rocking shear wall with post-tensioned rods to provide system re-centering. These post-tensioned rods add axial load to the shear wall and potentially endure long term creep affects. Mass Timber buildings consist of cross laminated (clt) shear walls and floor slabs along with glulam beams. The flexural capacity of the CLT floor slabs along with dead load can provide an alternative source for the restoring force. This project developed a test setup …

Crude Palm Oil Prediction Based On Back Propagation Neutral Network Approach, Hijratul Aini, Haviluddin Haviluddin

Knowledge Engineering and Data Science

Crude palm oil (CPO) production at PT. Perkebunan Nusantara (PTPN) XIII from January 2015 to January 2018 have been treated. This paper aims to predict CPO production using intelligent algorithms called Backpropagation Neural Network (BPNN). The accuracy of prediction algorithms have been measured by mean square error (MSE). The experiment showed that the best hidden layer architecture (HLA) is 5-10-11-12-13-1 with learning function (LF) of trainlm, activation function (AF) of logsig and purelin, and learning rate (LR) of 0.5. This architecture has a good accuracy with MSE of 0.0643. The results showed that this model can predict CPO production in …

The Diffusion Of Ict For Corruption Detectionin Open Government Data, Darusalam Darusalam, Jamaliah Said, Normah Omar, Marijn Janssen, Kazi Sohag

Knowledge Engineering and Data Science

Corruption occurs in many places within the government. To tackle the issue, open data can be used as one of the tools in creating more insight into the government. The premise of this paper is to support the notion that data opening can bring up new ways of fighting corruption. The current paper aimed at investigating how open data can be employed to detect corruption. This open data is trivial due to challenges like information asymmetry among stakeholders, data might only be opened partly, different sources of data need to be combined, and data might not be easy to use, …

Prediction Of Noise Associated With An Isolated Uav Propeller, Samuel O. Afari

Doctoral Dissertations and Master's Theses

The emergent field of interest in the Urban Air Mobility community is geared towards a world where aerial vehicles are commonplace. This poses the problem of the effects of the radiated noise. The present research presents an in-depth analysis of the noise generation mechanism of a propeller as a mode of propulsion of the said aerial vehicles. Numerical simulation utilizing a Hybrid Large-Eddy Simulation (LES) coupled with Unsteady Reynolds-Averaged Navier-Stokes (RANS) solver, is adopted on an isolated propeller modeled from the commercial DJI Phantom II 9450 propeller. The Spalart-Allmaras one equation turbulence model with rotation/curvature correction is used. The Farassat’s …