Comparison Of Conventional And Adaptive Acoustic Beamforming Algorithms Using A Tetrahedral Microphone Array In Noisy Environments,
2024
Portland State University
Comparison Of Conventional And Adaptive Acoustic Beamforming Algorithms Using A Tetrahedral Microphone Array In Noisy Environments, Megan Brittany Ewers
Dissertations and Theses
In situ acoustic measurements are often plagued by interfering sound sources that occur within the measurement environment. Both adaptive and conventional beamforming algorithms, when applied to the outputs of a microphone array arranged in a tetrahedral geometry, are able to capture sound sources in desired directions and reject sound from unwanted directions. Adaptive algorithms may be able to measure a desired sound source with greater spatial precision, but require more calculations and, therefore, computational power. A conventional frequency-domain phase-shift algorithm and a modified adaptive frequency-domain Minimum Variance Distortionless Response (MVDR) algorithm were applied to simulated and recorded signals from a …
Impact Of Welding Parameters In The Porosity Of A Dissimilar Welded Lap Joint Of Cp800-Xpf1000 Steel Weldment By Gmaw-P,
2024
The University of Texas Rio Grande Valley
Impact Of Welding Parameters In The Porosity Of A Dissimilar Welded Lap Joint Of Cp800-Xpf1000 Steel Weldment By Gmaw-P, Julio Cesar Garcia-Guerrero, Francisco Fernando Curiel-López, Víctor Hugo López-Morelos, Jaime Taha-Tijerina, Teresita Jesus Sánchez-Cruz, Maria Del Carmen Ramirez-Lopez, Eduardo Cortes-Carillo, Miguel Angel Quinones-Salinas
Informatics and Engineering Systems Faculty Publications and Presentations
The use of the orthogonal array L4 allows a determination of the effect between the welding parameters peak current (Ip), background current (Ib) and frequency (f) on the porosities in a dissimilar welded lap joint of CP800 and XPF1000 steel weldment by the gas metal arc welding process with the transfer pulsed mode. According to the results, modifications in the welding parameters affect the heat input during welding. A heat input higher than 0.30 KJ/mm generates up to 0.32% porosity in the weld metal, while a heat input lower than 0.25 KJ/mm generates up to 28% porosity in the weld …
Machine Learning A Universal Harmonic Interatomic Potential For Predicting Phonons In Crystalline Solids,
2024
Portland State University
Machine Learning A Universal Harmonic Interatomic Potential For Predicting Phonons In Crystalline Solids, Huiju Lee, Yi Xia
Mechanical and Materials Engineering Faculty Publications and Presentations
Phonons, as quantized vibrational modes in crystalline materials, play a crucial role in determining a wide range of physical properties, such as thermal and electrical conductivity, making their study a cornerstone in materials science. In this study, we present a simple yet effective strategy for deep learning harmonic phonons in crystalline solids by leveraging existing phonon databases and state-of-the-art machine learning techniques. The key of our method lies in transforming existing phonon datasets, primarily represented in interatomic force constants, into a force-displacement representation suitable for training machine learning universal interatomic potentials. By applying our approach to one of the largest …
Increasing The Dissolution Rate Of Polystyrene Waste In Solvent-Based Recycling,
2024
Universiteit Gent
Increasing The Dissolution Rate Of Polystyrene Waste In Solvent-Based Recycling, Rita Kol, Ruben Denolf, Gwendoline Bernaert, Dave Manhaeghe, Ezra Bar Ziv, George W. Huber, Norbert Niessner, Michiel Verswyvel, Angeliki Lemonidou, Dimitris S. Achilias, Steven De Meester
Michigan Tech Publications, Part 2
Solvent-based recycling of plastic waste is a promising approach for cleaning polymer chains without breaking them. However, the time required to actually dissolve the polymer in a lab environment can take hours. Different factors play a role in polymer dissolution, including temperature, turbulence, and solvent properties. This work provides insights into bottlenecks and opportunities to increase the dissolution rate of polystyrene in solvents. The paper starts with a broad solvent screening in which the dissolution times are compared. Based on the experimental results, a multiple regression model is constructed, which shows that within several solvent properties, the viscosity of the …
Effects Of Redrying Methods On The Milling Potential, Crude Protein And Total Phenolic Content, And Antioxidant Activity Of Stored Inorganic And Organically-Grown Paddy,
2024
PhilRice Batac, City of Batac, Ilocos Norte, Philippines
Effects Of Redrying Methods On The Milling Potential, Crude Protein And Total Phenolic Content, And Antioxidant Activity Of Stored Inorganic And Organically-Grown Paddy, Mary Ann Baradi, Jessica Solero, Clarence Dangcil, Gerome Corpuz, Marissa Romero
The Philippine Agricultural Scientist
This study sought to determine the effects of redrying techniques (no redrying or Control, 2-h, 4-h, and 6-h redrying with stirring every 30 min, Farmer's Practice or 6-h redrying with one stirring) on grain quality of stored inorganic and organic paddy rice as well as the redrying method that gives the best quality rice. PSB Rc82 rice harvested in October 2016 was used in the experiment conducted in February 2017. Quality parameters evaluated were moisture content, brown rice, total milled rice, crude protein content in percent, total phenolic content, and 2-2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. PSB Rc82 paddy exposed …
Experimental Investigation Of Long-Term Performance Of Fiber-Reinforced Epoxy And Polyurethane Polymer Composites,
2024
United Arab Emirates University
Experimental Investigation Of Long-Term Performance Of Fiber-Reinforced Epoxy And Polyurethane Polymer Composites, Abdel Hamid I. Mourad, Amir Hussain Idrisi, Asima Zahoor, Muhammad M. Sherif, Beckry M. Abdel-Magid
Michigan Tech Publications, Part 2
The primary challenge encountered by polymers and their composites when exposed to saline water is their inadequate ability to withstand wear and tear over time. With a potential to replace conventional materials the long-term performance of FRP composites is still a novice area. This manuscript thus, reports an experimental investigation and prediction of the durability of fiber-reinforced polymer composites exposed to seawater at different temperatures. E-glass/epoxy and E-glass/polyurethane samples were exposed to 23 °C, 45 °C and 65 °C seawater for up to 2700 days (90 months). Tensile tests evaluated the mechanical performance of the composite as a function of …
Wavelength-Induced Shedding Frequency Modulation Of Seal Whisker Inspired Cylinders,
2024
University of Wisconsin-Madison
Wavelength-Induced Shedding Frequency Modulation Of Seal Whisker Inspired Cylinders, Trevor Dunt, Kirby S. Heck, Kathleen Lyons, Christin Murphy, Raul Bayoan Cal, Jennifer A. Franck
Mechanical and Materials Engineering Faculty Publications and Presentations
The spanwise undulated cylinder geometry inspired by seal whiskers has been shown to alter shedding frequency and reduce fluid forces significantly compared to smooth cylindrical geometry. Undulation wavelength is systematically investigated in order to explore its effect on unsteady lift force and shedding frequency. Prior research has parameterized the whisker-inspired geometry and demonstrated the relevance of geometric variations on force reduction properties. Among the geometric parameters, undulation wavelength was identified as a significant contributor to forcing changes. To analyze the effect of undulation wavelength, a thorough investigation isolating changes in wavelength is performed to expand upon previous research that parameterized …
Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait,
2024
California Polytechnic State University, San Luis Obispo
Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait, Timothy S. Jain
Master's Theses
Total ankle replacement (TAR) implants are an effective option to restore the range of motion of the ankle joint for arthritic patients. An effective tool for analyzing these implants’ mechanical performance and longevity in-silico is finite element analysis (FEA). ABAQUS FEA was used to statically analyze the von Mises stress and contact pressure on the articulating surface of the bearing component in two newly installed fixed-bearing total ankle replacement implants (the Wright Medical INBONE II and the Exactech Vantage). This bearing component rotates on the talar component to induce primary ankle joint motion of plantarflexion and dorsiflexion. The stress response …
Characterization Of Microstructural And Mechanical Properties Of 17-4 Ph Stainless Steel By Cold Rolled And Machining Vs. Dmls Additive Manufacturing,
2024
The University of Texas Rio Grande Valley
Characterization Of Microstructural And Mechanical Properties Of 17-4 Ph Stainless Steel By Cold Rolled And Machining Vs. Dmls Additive Manufacturing, Pablo Moreno-Garibaldi, Melvyn Alvarez-Vera, Juan Alfonso Beltrán-Fernández, Rafael Carrera-Espinoza, Héctor Manuel Hdz-García, J. C. Díaz-Guillen, Rita Muñoz-Arroyo, Javier A. Ortega, Paul Molenda
Mechanical Engineering Faculty Publications and Presentations
The 17-4 PH stainless steel is widely used in the aerospace, petrochemical, chemical, food, and general metallurgical industries. The present study was conducted to analyze the mechanical properties of two types of 17-4 PH stainless steel—commercial cold-rolled and direct metal laser sintering (DMLS) manufactured. This study employed linear and nonlinear tensile FEM simulations, combined with various materials characterization techniques such as tensile testing and nanoindentation. Moreover, microstructural analysis was performed using metallographic techniques, optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results on the microstructure for 17-4 PH DMLS stainless steel reveal …
Atomistic Insights Into The Mechanisms Of Ultrasonic Bonding,
2024
Santa Clara University
Atomistic Insights Into The Mechanisms Of Ultrasonic Bonding, Milad Khajehvand
Engineering Ph.D. Theses
This thesis research uses a combination of computational and experimental approaches to provide atomistic insights into the mechanisms of ultrasonic bonding (UB), a family of solid-state metal-metal joining techniques, including ultrasonic wire bonding, ultrasonic flip-chip bonding, ultrasonic additive manufacturing, and ultrasonic spot welding. The work investigates the atomic-scale contact formation (i.e., the so-called Jump-to-Contact (JC) mechanism) between the UB counterparts, generation of a network of dislocations (i.e., one-dimensional crystallographic defects) at their interface, and the evolution of the network when the interface is under ultrasonic vibration. In particular, the thesis delivers invaluable insights on the mechanisms for contact formation, bond …
Jet-Driven Mixing Regimes Identified In The Unsteady Isothermal Filling Of Rectangular Municipal Water Storage Tanks,
2024
Missouri University of Science and Technology
Jet-Driven Mixing Regimes Identified In The Unsteady Isothermal Filling Of Rectangular Municipal Water Storage Tanks, Pramod Narayan Bangalore, K. (Kelly) O. Homan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Poor mixing of old and new water in municipal water storage vessels is a well-documented basis for potentially harmful water quality degradation in drinking water distribution systems. This numerical study investigates the effects of inflow and operational variables on mixing in the jet-driven filling process, with a particular focus on the transition from inadequate to sufficient mixing levels. An isothermal unsteady reynolds-averaged-navier-stokes volume-of-fluid (RANS-VOF) simulation is used to model the variable-volume filling process, accounting for the moving free surface following a draw-down in the stored water volume. A low diffusivity tracer is used to mark the old-water volume, and a …
Efficacy Of Passive Ventilation With High Exhaust Demands: A Case Study Of Cal Poly Sst,
2024
California Polytechnic State University, San Luis Obispo
Efficacy Of Passive Ventilation With High Exhaust Demands: A Case Study Of Cal Poly Sst, Siddarth Bokka
Construction Management
The Simpson Strong Tie Demonstration Laboratory serves as a multipurpose space allowing students at the College of Architecture and Environmental Design at California Polytechnic State University to build full scale construction projects. The building features a material storage area, a high bay for construction of full-scale projects, and a mezzanine level that houses digital fabrication equipment. However, the building was never designed to house the specific equipment currently installed on the mezzanine and ventilate the exhaust fumes from them. Rather, the building relies on passive natural ventilation that is likely ineffective at properly exhausting hazardous fumes, resulting in complaints from …
Heat Treatments For Minimization Of Residual Stresses And Maximization Of Tensile Strengths Of Scalmalloy® Processed Via Directed Energy Deposition,
2024
Missouri University of Science and Technology
Heat Treatments For Minimization Of Residual Stresses And Maximization Of Tensile Strengths Of Scalmalloy® Processed Via Directed Energy Deposition, Rachel Boillat-Newport, Sriram Praneeth Isanaka, Jonathan Kelley, Frank Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Scalmalloy® is an Al-Mg-Sc-Zr-Based Alloy Specifically Developed for Additive Manufacturing (AM). This Alloy is Designed for Use with a Direct Aging Treatment, as Recommended by the Manufacturer, Rather Than with a Multistep Treatment, as Often Seen in Conventional Manufacturing. Most Work with Scalmalloy® is Conducted using Powder Bed Rather Than Powder-Fed Processes. This Investigation Seeks to Fill This Knowledge Gap and Expand Beyond Single-Step Aging to Promote an overall Balanced AM-Fabricated Component. for This Study, Directed Energy Deposition (DED)-Fabricated Scalmalloy® Components Were Subjected to Low-Temperature Treatments to Minimize Residual Stresses Inherent in the Material Due to the Layer-By-Layer Build Process. …
A Study On High-Frequency Bending Fatigue, Microhardness, Tensile Strength, And Microstructure Of Parts Made Using Atomic Diffusion Additive Manufacturing (Adam) And Additive Friction Stir Deposition (Afsd),
2024
Louisiana State University and Agricultural and Mechanical College
A Study On High-Frequency Bending Fatigue, Microhardness, Tensile Strength, And Microstructure Of Parts Made Using Atomic Diffusion Additive Manufacturing (Adam) And Additive Friction Stir Deposition (Afsd), Hamed Ghadimi
LSU Doctoral Dissertations
This dissertation reports the findings of several studies on the mechanical and microstructural properties of parts made using atomic diffusion additive manufacturing (ADAM) and additive friction stir deposition (AFSD). The design of a small-sized bending-fatigue test specimen for an ultrasonic fatigue testing system is reported in Chapter 1. The design was optimized based on the finite element analysis and analytical solution. The stress–life (S–N) curve is obtained for Inconel alloy 718. Chapter 2 presents the findings of ultrasonic bending-fatigue and tensile tests carried out on the ADAM test specimens. The S-N curves were created in the very high-cycle fatigue regime. …
Wire Texture C-Axis Distribution Of Strontium Ferrite/Pa-12 Extruded Filament,
2024
The University of Texas Rio Grande Valley
Wire Texture C-Axis Distribution Of Strontium Ferrite/Pa-12 Extruded Filament, Gabriela Espinosa-Rodriguez, Oluwasola Arigbabowo, Jonathan Alvarado, Jitendra Tate, Wilhelmus J. Geerts
Mechanical Engineering Faculty Publications and Presentations
The magnetic anisotropy of strontium ferrite (SF)/PA12 filament, a popular hard magnetic ferrimagnetic composites that is used for 3D-printing of permanent magnets, is studied by vibrating sample magnetometry. The studied filaments have a composition of SF/PA-12 thermoplastic composite with a 40% wt. ratio of SF. SF particles are non-spherical platelets with an average diameter of 1.3 um and a diameter to thickness ratio of 3. Filaments are produced by a twin-screw extruder and have a diameter of 1.5 mm. SEM images show that the SF particles are homogeneously distributed through the filament. VSM measurements on different parts of the filaments …
Residual Stress Generation In Additive Manufacturing Of Complex Lattice Geometries,
2024
Wright State University
Residual Stress Generation In Additive Manufacturing Of Complex Lattice Geometries, Katie Bruggeman, Nathan Klingbeil, Anthony N. Palazotto
Faculty Publications
Residual stresses developed during additive manufacturing (AM) can influence the mechanical performance of structural components in their intended applications. In this study, thermomechanical residual stress simulations of the laser powder bed fusion (LPBF) process are conducted for both simplified (plate and cube-shaped) geometries as well as five complex lattice geometries fabricated with Inconel 718. These simulations are conducted with the commercial software package Simufact Additive©, which uses a nonlinear finite element analysis and layer-by-layer averaging approach in determining residual stresses. To verify the efficacy of the Simufact Additive© simulations, numerical results for the plate and cube-shape geometries are analyzed for …
Tribological Properties Of H-Bn, Ag And Mgo Nanostructures As Lubricant Additives In Vegetable Oils,
2024
The University of Texas Rio Grande Valley
Tribological Properties Of H-Bn, Ag And Mgo Nanostructures As Lubricant Additives In Vegetable Oils, Victoria Granja, Kollol Sarker Jogesh, Jaime Taha-Tijerina, C. Fred Higgs Iii
Informatics and Engineering Systems Faculty Publications and Presentations
There exists an ever-growing need for sustainable engineering solutions to improve emission control and the energy efficiency of tribosystems. This study examines the tribological properties of two environmentally friendly vegetable fluids, soybean and sunflower oil, with the addition of three non-toxic nanostructures (h-BN, silver and MgO) at different concentrations. It was found that nanostructures added to vegetable oils at specific concentrations can exhibit good friction reduction and wear preventive properties. The addition of h-BN nanosheets in sunflower oil decreased the coefficient of friction and the wear damage, as measured by the wear scar diameter. Silver and magnesium oxide nanoparticles further …
Simulation Of The Multi-Wake Evolution Of Two Sandia National Labs/National Rotor Testbed Turbines Operating In A Tandem Layout,
2024
Michigan Technological University
Simulation Of The Multi-Wake Evolution Of Two Sandia National Labs/National Rotor Testbed Turbines Operating In A Tandem Layout, Apurva Baruah, Fernando L. Ponta, Alayna Farrell
Michigan Tech Publications, Part 2
The future of wind power systems deployment is in the form of wind farms comprised of scores of such large turbines, most likely at offshore locations. Individual turbines have grown in span from a few tens of meters to today’s large turbines with rotor diameters that dwarf even the largest commercial aircraft. These massive dynamical systems present unique challenges at scales unparalleled in prior applications of wind science research. Fundamental to this effort is the understanding of the wind turbine wake and its evolution. Furthermore, the optimization of the entire wind farm depends on the evolution of the wakes of …
Key Elements, Mechanism Analysis And Evaluation Indicators Of Digital And Intelligent Integration Transformation And Development Of Manufacturing Industry,
2024
College of Economics and Management, Qingdao University of Science and Technology, Qingdao 266061, China
Key Elements, Mechanism Analysis And Evaluation Indicators Of Digital And Intelligent Integration Transformation And Development Of Manufacturing Industry, Xiaoqiang Sun, Xiuyun Gao, Yumei Wang
Bulletin of Chinese Academy of Sciences (Chinese Version)
The digital and intelligent integration transformation of manufacturing industry has become an important driving force for the high-quality development of traditional manufacturing enterprises. This study clarifies the main research context and key issues of scholars on the digital and intelligent integration transformation of manufacturing industry, refines the goals, main elements, and influencing factors of digital and intelligent integration transformation of manufacturing industry, builds a power network model for the transformation and development of digital and intelligent integration of manufacturing industry according to the system feedback principle of system dynamics, analyzes the mechanism of action between various elements of the system, …
Electric Vehicles Contribute To China's Energy Security And Carbon Peaking And Carbon Neutrality,
2024
Institutes of Science and Development, Chinese Academy of Sciences, Beijing 100190, China
School of Public Policy and Management, University of Chinese Academy of Sciences, Beijing 100049, China
Electric Vehicles Contribute To China's Energy Security And Carbon Peaking And Carbon Neutrality, Jianfeng Guo, Xuemei Zhang, Qi Cao, Fu Gu
Bulletin of Chinese Academy of Sciences (Chinese Version)
The current international situation is complicated and unstable, and China is in the midst of an important economic transition as it deals with the twin concerns of energy security and carbon peaking and carbon neutrality (referred to as dual carbon goals). Although the dual carbon goals aim a strong emphasis on energy security, certain emission reduction strategies will place restrictions on energy security that is directly connected, such as energy supply and grid load, making it challenging to simultaneously fulfill the optimization goal. China now has the task of figuring out how to rationalize and optimize the coordinated promotion of …
