Engineering Commons^™

Surface And Interface Properties In Thin-Film Solar Cells: Using Soft X-Rays And Electrons To Unravel The Electronic And Chemical Structure, Lothar Weinhardt, Dirk Hauschild, Clemens Heske

Chemistry and Biochemistry Faculty Research

Thin‐film solar cells have great potential to overtake the currently dominant silicon‐based solar cell technologies in a strongly growing market. Such thin‐film devices consist of a multilayer structure, for which charge‐carrier transport across interfaces plays a crucial role in minimizing the associated recombination losses and achieving high solar conversion efficiencies. Further development can strongly profit from a high‐level characterization that gives a local, electronic, and chemical picture of the interface properties, which allows for an insight‐driven optimization. Herein, the authors' recent progress of applying a “toolbox” of high‐level laboratory‐ and synchrotron‐based electron and soft X‐ray spectroscopies to characterize the chemical …

Flow-Induced Stresses And Displacements In Jointed Concrete Pipes Installed By Pipe Jacking Method, Moses Karakouzian, Mehrdad Karami, Mohammad Nazari-Sharabian, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Transient flows result in unbalanced forces and high pressure in pipelines. Under these conditions, the combined effects of flow-induced forces along with sudden pipe displacements can create cracks in the pipeline, especially at the junctions. This situation consequently results in water leakage and reduced operational efficiency of the pipeline. In this study, displacements and stresses in a buried pressurized water transmission pipe installed by pipe jacking method are investigated using numerical modeling and considering interactions between fluid, pipe, and soil. The analyses were performed consecutively under no-flow, steady flow, and transient flow conditions, in order to investigate the effects of …

Polydopamine And Collagen Coated Micro-Grated Polydimethylsiloxane For Human Mesenchymal Stem Cell Culture, Dhavan Sharma, Wenkai Jia, Fei Long, Shweta Pati, Qing-Hui Chen, Yibing Qyang, Bruce P. Lee, Chang Kyoung Choi, Feng Zhao

Department of Biomedical Engineering Publications

Natural tissues contain highly organized cellular architecture. One of the major challenges in tissue engineering is to develop engineered tissue constructs that promote cellular growth in physiological directionality. To address this issue, micro-patterned polydimethylsiloxane (PDMS) substrates have been widely used in cell sheet engineering due to their low microfabrication cost, higher stability, excellent biocompatibility, and most importantly, ability to guide cellular growth and patterning. However, the current methods for PDMS surface modification either require a complicated procedure or generate a non-uniform surface coating, leading to the production of poor-quality cell layers. A simple and efficient surface coating method is critically …

Linear Stability Analysis Of Subaqueous Bedforms Using Direct Numerical Simulations, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We present results on the formation of ripples from linear stability analysis. The analysis is coupled with direct numerical simulations of turbulent open-channel flow over a fixed sinusoidal bed. The presence of the sediment bed is accounted for using the immersed boundary method. The simulations are used to extract the bed shear stress and consequently the sediment transport rate. The approach is different from traditional linear stability analysis in the sense that the phase lag between the bed topology and the sediment flux is obtained from the three-dimensional turbulent simulations. The stability analysis is performed on the Exner equation, whose …

Project Selection: The $1 Trillion Decisions, Leonard Nethercutt

Operations Management Presentations

This webinar will discuss project selection with a focus on both strategic and fi­nancial factors. Project selection directly influences the future results of a busi­ness either positively or negatively over time. During this presentation, we will examine the important link between strategic management, project management, and operations management to create future results and value. You will learn project selection methods and tips to help your organization make a positive impact on the future of your business.

Quantifying And Correcting For Clay Content Effects On Soil Water Measurement By Reflectometers, Jasreman Singh, Tsz Him Lo, Daran Rudnick, Suat Irmak, Humberto Blanco-Canqui

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The presence of clay particles increases the specific surface area of a soil and can affect the calibration of electromagnetic soil water sensors including reflectometers. To quantify and correct for this effect in two relatively new reflectometers, three TDR315 and three CS655 sensors were installed in each of five soils with clay content ranging from 5 to 49%. As the soils were dried in a temperature controlled room, sensor reported soil volumetric water content (θ_v) according to the factory calibration was compared against reference θ_v determined by weighing the soils. Sensor reported θ_v was similar to …

Near-Surface Material Phases And Microstructure Of Scandate Cathodes, Xiaotao Liu, Bernard K. Vancil, Matthew J. Beck, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Scandate cathodes that were fabricated using the liquid-solid process and that exhibited excellent emission performance were characterized using complementary state-of-the-art electron microscopy techniques. Sub-micron BaAl₂O₄ particles were observed on the surfaces and edges of tungsten particles, as seen in cross-section samples extracted from the scandate cathode surface regions. Although several BaAl₂O₄ particles were observed to surround smaller Sc₂O₃ nanoparticles, no chemical mixing of the two oxides was detected, and in fact the distinct oxide phases were separately verified by chemical analysis and also by 3D elemental tomography. Nanobeam electron diffraction confirmed …

Usu Aggieair Program Selected For Critical National Airspace Operation | College Of Engineering, Utah State University

College of Engineering News

Utah State University’s premier unmanned aerial systems organization will take part in a highly anticipated NASA-led operation.

Compensating Misalignment Using Dynamic Random-Effect Control System: A Case Of High-Mixed Wafer Fabrication, Marzieh Khakifirooz, Chen-Fu Chien, Mahdi Fathi

BCoE Publications

It is vital to have an exclusive modification in semiconductor production process because of meeting differentiated customer demands in dynamic and competitive global minuscule semiconductor technology market and the highly complex fabrication process. In this paper, we propose a control system based on the dynamic mixed-effect least-square support vector regression (LS-SVR) control system for overlay error compensation with stochastic metrology delay to minimize the misalignment of the patterning process. Moreover, for the stability of the control system in the presence of metrology delay and to deal with nonlinearity among the overlay factors, the novel Lyapunov-based kernel function is merged with …

Characterization And Quantification Of Highly Sulfated Glycosaminoglycan Isomers By Gated-Trapped Ion Mobility Spectrometry Negative Electron Transfer Dissociation Ms/Ms, Juan Wei, Jiandong Wu, Yang Tang, Mark E. Ridgeway, Melvin A. Park, Catherine E. Costello, Joseph Zaia, Cheng Lin

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glycosaminoglycans (GAGs) Play Vital Roles in Many Biological Processes and Are Naturally Present as Complex Mixtures of Polysaccharides with Tremendous Structural Heterogeneity, Including Many Structural Isomers. Mass Spectrometric Analysis of GAG Isomers, in Particular Highly Sulfated Heparin (Hep) and Heparan Sulfate (HS), is Challenging Because of their Structural Similarity and Facile Sulfo Losses during Analysis. Herein, We Show that Highly Sulfated Hep/HS Isomers May Be Resolved by Gated-Trapped Ion Mobility Spectrometry (Gated-TIMS) with Negligible Sulfo Losses. Subsequent Negative Electron Transfer Dissociation (NETD) Tandem Mass Spectrometry (MS/MS) Analysis of TIMS-Separated Hep/HS Isomers Generated Extensive Glycosidic and Cross-Ring Fragments for Confident Isomer …

Substrate Support Ring For More Uniform Layer Thickness, Heng Pan, Lara Hawrylchak, Christopher S. Olsen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Embodiments of substrate support rings providing more uniform thickness of layers deposited or grown on a substrate are provided herein. In some embodiments, a substrate support ring includes: an inner ring with a centrally located support surface to support a substrate; and an outer ring extending radially outward from the support surface, wherein the outer ring comprises a reaction surface area disposed above and generally parallel to a support plane of the support surface, and wherein the reaction surface extends beyond the support surface by about 24 mm to about 45 mm.

The Bridge Between Beauty And Functionality, Justin R. Vander Werff

Faculty Work Comprehensive List

"While our human creatureliness and limited understanding often lead us to pit form and function against each other, God provides glimpses of their unity."

Posting about ­­­­­­­­balancing aesthetics and practicality in design from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.

https://inallthings.org/the-bridge-between-beauty-and-functionality/

Forcespinning Technique For The Production Of Poly(D,L-Lactic Acid) Submicrometer Fibers: Process–Morphology–Properties Relationship, Victoria Padilla-Gainza, Graciela Morales, Heriberto Rodríguez-Tobías, Karen Lozano

Mechanical Engineering Faculty Publications

This work addresses a systematic study for the process development and optimization of poly(d,l-lactic acid) (PDLLA) submicrometer fibers utilizing the centrifugal spinning technique known as Forcespinning. This study analyzes the effect of polymer concentration (8, 10, and 12 wt %) and angular speed on the fiber morphology, diameter distribution, and fiber yield. The increase in polymer concentration and angular speed favored the formation of continuous and homogeneous submicrometer fibers with an absence of bead formation and higher output. The optimal conditions were established considering the morphological characteristics that exhibit a greater surface area (homogeneous and submicrometer fibers); and they were …

Myopic Versus Farsighted Behaviors In A Low-Carbon Supply Chain With Reference Emission Effects, Jun Wang, Xianxue Cheng, Xinyu Wang, Hongtao Yang, Shuhua Zhang

Mathematical Sciences Faculty Research

The increased carbon emissions cause relatively climate deterioration and attract more attention of governments, consumers, and enterprises to the low-carbon manufacturing. This paper considers a dynamic supply chain, which is composed of a manufacturer and a retailer, in the presence of the cap-and-trade regulation and the consumers’ reference emission effects. To investigate the manufacturer’s behavior choice and its impacts on the emission reduction and pricing strategies together with the profits of both the channel members, we develop a Stackelberg differential game model in which the manufacturer acts in both myopic and farsighted manners. By comparing the equilibrium strategies, it can …

Applications Of Supervised Machine Learning In Autism Spectrum Disorder Research: A Review, Kayleigh K. Hyde, Marlena N. Novack, Nicholas Lahaye, Chelsea Parlett-Pelleriti, Raymond Anden, Dennis R. Dixon, Erik Linstead

Engineering Faculty Articles and Research

Autism spectrum disorder (ASD) research has yet to leverage "big data" on the same scale as other fields; however, advancements in easy, affordable data collection and analysis may soon make this a reality. Indeed, there has been a notable increase in research literature evaluating the effectiveness of machine learning for diagnosing ASD, exploring its genetic underpinnings, and designing effective interventions. This paper provides a comprehensive review of 45 papers utilizing supervised machine learning in ASD, including algorithms for classification and text analysis. The goal of the paper is to identify and describe supervised machine learning trends in ASD literature as …

Harnessing Neurovascular Interaction To Guide Axon Growth., Paul P Partyka, Ying Jin, Julien Bouyer, Angelica Dasilva, George A Godsey, Robert G Nagele, Itzhak Fischer, Peter Galie

Henry M. Rowan College of Engineering Departmental Research

Regulating the intrinsic interactions between blood vessels and nerve cells has the potential to enhance repair and regeneration of the central nervous system. Here, we evaluate the efficacy of aligned microvessels to induce and control directional axon growth from neural progenitor cells in vitro and host axons in a rat spinal cord injury model. Interstitial fluid flow aligned microvessels generated from co-cultures of cerebral-derived endothelial cells and pericytes in a three-dimensional scaffold. The endothelial barrier function was evaluated by immunostaining for tight junction proteins and quantifying the permeability coefficient t (~10−7 cm/s). Addition of neural progenitor cells to the co-culture …

The Influence Of Asphalt Ageing On Induction Healing Effect On Porous Asphalt Concrete, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Induction healing is a proven technology which is able to improve the self‐healing capacity of asphalt concrete. Healing is achieved via electromagnetic current produced by passing induction machine, where steel asphalt constituents heat up which in turn soften the bitumen in the asphalt layer, allowing it to flow and close cracks, repairing the damage. This paper reports on the study which investigated the influence of ageing on the healing capacity of Porous Asphalt (PA) concrete. Porous Asphalt concrete mix was prepared first, then subjected to an accelerated (laboratory) ageing process using a ventilated oven. In order to further evaluate the …

American Sign Language Recognition Using Machine Learning And Computer Vision, Kshitij Bantupalli, Ying Xie

Master of Science in Computer Science Theses

Speech impairment is a disability which affects an individual’s ability to communicate using speech and hearing. People who are affected by this use other media of communication such as sign language. Although sign language is ubiquitous in recent times, there remains a challenge for non-sign language speakers to communicate with sign language speakers or signers. With recent advances in deep learning and computer vision there has been promising progress in the fields of motion and gesture recognition using deep learning and computer vision-based techniques. The focus of this work is to create a vision-based application which offers sign language translation …

Modeling Of Grace-Derived Groundwater Information In The Colorado River Basin, Md Mafuzur Rahaman, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Groundwater depletion has been one of the major challenges in recent years. Analysis of groundwater levels can be beneficial for groundwater management. The National Aeronautics and Space Administration’s twin satellite, Gravity Recovery and Climate Experiment (GRACE), serves in monitoring terrestrial water storage. Increasing freshwater demand amidst recent drought (2000–2014) posed a significant groundwater level decline within the Colorado River Basin (CRB). In the current study, a non-parametric technique was utilized to analyze historical groundwater variability. Additionally, a stochastic Autoregressive Integrated Moving Average (ARIMA) model was developed and tested to forecast the GRACE-derived groundwater anomalies within the CRB. The ARIMA model …

Dynamic Response Of A Tunable Mems Accelerometer Based On Repulsive Force, Meysam Daeichin, Mehmet Ozdogan, Shahrzad Towfighian, Ronald Miles

Mechanical Engineering Faculty Scholarship

This paper describes a tunable MEMS electrostatic accelerometer that uses repulsive electrode configuration so that the design is not hampered by capacitive pull-in instability. The repulsive force configuration enables the increase of DC bias voltage without suffering from the pull-in failure mode. This flexibility in increasing voltage can be employed as a tuning parameter to widen the working frequency range and to improve the robustness of the accelerometer. A lumped parameter model is developed to simulate the response of the microstructure under a combination of electrostatic and dynamic mechanical loading. The electrostatic force is estimated using a finite element simulation. …

Muscle Atrophy Marker Expression Differs Between Rotary Cell Culture System And Animal Studies, Charles P. Harding, Elizabeth Vargis

Biological Engineering Faculty Publications

Muscular atrophy, defined as the loss of muscle tissue, is a serious issue for immobilized patients on Earth and for humans during spaceflight, where microgravity prevents normal muscle loading. In vitro modeling is an important step in understanding atrophy mechanisms and testing countermeasures before animal trials. The most ideal environment for modeling must be empirically determined to best mimic known responses in vivo. To simulate microgravity conditions, murine C2C12 myoblasts were cultured in a rotary cell culture system (RCCS). Alginate encapsulation was compared against polystyrene microcarrier beads as a substrate for culturing these adherent muscle cells. Changes after culture …

Aesthetics, Ethics, And Lose-Lose Dilemmas In The Anthropocen, Adam Liska

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Anthropogenic climate change will cause violence to increase globally, and nonlinear increases in sea level could cause a major escalation in global conflict. After 2100, a 22-meter sea-level rise is estimated here to dislocate two billion people from coastal areas. These impending civilization-changing events require us to again reevaluate our prevalent aesthetic preferences for luxury that produce a significant fraction of anthropogenic greenhouse gas emissions. Due to industrial inertia, a central dilemma discussed here is the contradictions between the goals and impacts of aesthetics and ethics. Either we lose our own well-being (a loss of high-emission aesthetics) for the benefit …

Identification Of Critical Source Areas (Csas) And Evaluation Of Best Management Practices (Bmps) In Controlling Eutrophication In The Dez River Basin, Hadi Babaei, Mohammad Nazari-Sharabian, Moses Karakouzian, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Best Management Practices (BMPs) are commonly used to control pollution in the river basins. Prioritization of BMPs helps improve the efficiency and effectiveness of pollution reduction, especially in Critical Source Areas (CSAs) that produce the highest pollution loads. Recently, the Dez River in Khuzestan, Iran, has become highly eutrophic from the overuse of fertilizers and pesticides. In this basin, dry and irrigated farming produce 77.34% and 6.3% of the Total Nitrogen (TN) load, and 83.56% and 4.3% of the Total Phosphorus (TP) load, respectively. In addition, residential, pasture, and forest land uses together account for 16.36% of the TN and …

A Hamiltonian Surface-Shaping Approach For Control System Analysis And The Design Of Nonlinear Wave Energy Converters, Shadi Darani, Ossama Abdelkhalik, Rush D. Robinett Iii, David Wilson

Department of Mechanical and Aerospace Engineering Publications

The dynamic model of Wave Energy Converters (WECs) may have nonlinearities due to several reasons such as a nonuniform buoy shape and/or nonlinear power takeoff units. This paper presents the Hamiltonian Surface-Shaping (HSS) approach as a tool for the analysis and design of nonlinear control of WECs. The Hamiltonian represents the stored energy in the system and can be constructed as a function of the WEC’s system states, its position, and velocity. The Hamiltonian surface is defined by the energy storage, while the system trajectories are constrained to this surface and determined by the power flows of the applied non-conservative …

The Influence Of Periodic Shear On Structural Relaxation And Pore Redistribution In Binary Glasses, Nikolai V. Priezjev, Maxim A. Makeev

Mechanical and Materials Engineering Faculty Publications

The evolution of porous structure, potential energy and local density in binary glasses under oscillatory shear deformation is investigated using molecular dynamics simulations. The porous glasses were initially prepared via a rapid thermal quench from the liquid state across the glass transition and allowed to phase separate and solidify at constant volume, thus producing an extended porous network in an amorphous solid. We find that under periodic shear, the potential energy decreases over consecutive cycles due to gradual rearrangement of the glassy material, and the minimum of the potential energy after thousands of shear cycles is lower at larger strain …

Optimal Design And Implementation Of Fractal Dipole Antenna Based On Arc Of Trigeminal Tree Structure, Xiaohong Zhang, Xiaoxiao Nan, Yixian Yang

Journal of System Simulation

Abstract: A RFID fractal dipole antenna is designed with the arc of the trigeminal tree structure, which is fed by simple microstrip balun to achieve better impedance matching within employing double parallel line structure and by using the dielectric substrate withε_r=4.4 and tan δ=0.035. The results of electromagnetic property simulation analysis of HFSS show that the return loss can reach 36dB, which is much higher than binary arc-shaped fractal antenna which is 16dB; and the impedance matching is very ideal. By physical processing and testing of the antenna, the measured results are in very good agreement with simulation …

The ‘Laminar Express’: Usu Engineers Dissect The Two-Seam Fastball | College Of Engineering, Utah State University

College of Engineering News

The worlds of engineering and baseball have collided. Researchers at Utah State University are breaking down the physics of a new baseball pitch that’s been getting a lot of attention.

Blind Separation Simulation System Of Sound Signals Based On Time-Frequency Analysis Of Short Time Fourier Transformation, Xiaorong Tong

Journal of System Simulation

Abstract: In order to improve the ability of real-time and separation accuracy, a blind separation algorithm based on time-frequency (TF) analysis of short time Fourier transformation is proposed, and the problems of underdetermined sound signal sorting can be solved effectively. The proposed method avoids some of the drawbacks, relaxes the assumption by allowing the sources to be TF-non-disjoint to a certain extent, and the algorithm can be achieved in the condition of TF-non-disjoint. This method was successfully applied to sound signal sorting system; the time domain waves of signals can be got; and the whole signal sorting process can be …

The Effect Of Calcination Rate On The Structure Of Mesoporous Bioactive Glasses, Saidur Rahman, Andrew Mendonca, Adel Alhalawani, Deanna Polintan, Owen M. Clarkin, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Mesoporous bioactive glasses (MBGs) are designed to have high specific surface area. They are formulated by a sol–gel process to formulate the glass followed by calcination. This study evaluates how calcination heating rate influences the porous architecture, and thereby the specific surface area, of MBGs. MBGs of molar ratio 80:15:5 for SiO₂ :CaO:P₂ O 5 were calcined using both low (1 °C/min) and high (20 °C/min) heating rates, termed as L-MBG and H-MBG, respectively. The results obtained from small-angle X-ray diffraction (SAXRD) confirm that the MBGs possess 2D hexagonal (P6mm) spacing groups and wide-angle XRD confirms the amorphicity …

Revealing The Effects Of Matrix Behavior On Low-Velocity Impact Response Of Continuous Fiber-Reinforced Thermoplastic Laminates, A. Yudhanto, H. Wafai, G. Lubineau, S. Goutham, M. Mulle, R. Yaldiz, N. Verghese

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Matrix behavior is expected to widely influence the impact response of composites, but detailed conclusions in the case of thermoplastic laminates are still needed. In this paper, we investigated the effect of using either ductile homopolymer PP or less-ductile impact copolymer PP matrices on the low-velocity impact responses of continuous glass fiber-reinforced polypropylene (PP) laminate. These PP types represent two variants in the same family of thermoplastic matrix. A thorough experimental campaign was first performed to provide the tensile properties (for PP and glass/PP) and fracture toughness (Mode-I and Mode-II, glass/PP only) of the employed materials. Then, low-velocity impact tests …