Mechanical Engineering Commons^™

External Direct Sum Invariant Subspace And Decomposition Of Coupled Differential-Difference Equations, Keqin Gu, Huan Phan-Van

SIUE Faculty Research, Scholarship, and Creative Activity

This article discusses the invariant subspaces that are restricted to be external direct sums. Some existence conditions are presented that facilitate finding such invariant subspaces. This problem is related to the decomposition of coupled differential-difference equations, leading to the possibility of lowering the dimensions of coupled differential-difference equations. As has been well documented, lowering the dimension of coupled differential-difference equations can drastically reduce the computational time needed in stability analysis when a complete quadratic Lyapunov-Krasovskii functional is used. Most known ad hoc methods of reducing the order are special cases of this formulation.

Effects Of Simultaneous Co2 Addition To The Fuel And Oxidizer Streams On Soot Formation In Co-Flow Diffusion Ethylene Flame, Yu Yang, Shu Zheng, Yuzhen He, Hao Liu, Ran Sui, Qiang Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Soot formation in a co-flow diffusion ethylene flame with the addition of CO₂ to the fuel (the CO₂-F), oxidizer (the CO₂-O), and fuel/oxidizer (the CO₂-F/O) streams was numerically and experimentally investigated in this study. The effects of different CO₂ addition ways on soot inception, soot condensation, H-abstraction-C₂H₂-addition (HACA) and oxidation by O₂/OH processes, were quantitatively analyzed by introducing the integrated reaction rates over the whole computational domain. The simulated and experimental results showed that the CO₂-F/O was the most effective in inhibiting soot formation …

The Investigation Of A Likely Scenario For Natural Tornado Genesis And Evolution From An Initial Instability Profile, Alexios Nicolas Philippou, Kakkattukuzhy M. Isaac

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A likely mechanism for the little-understood tornado genesis is proposed and its numerical implementation is presented. The Burgers-Rott vortex with its axis in the vertical direction is introduced as an instability mechanism, and the flow field then evolves under the influence of the atmospheric pressure, temperature and density variations with altitude. Buoyancy effects are implemented using the Boussinesq model. Results are presented and discussed for a set of conditions including mesh type and size, different turbulence models, and a few different boundary conditions. Post-processed results of the transient simulations including animations contain a wealth of information to help analyze tornado …

Wire Deflection Investigation During Wedm Of Aisi 304 Stainless Steel: An Experimental And Numerical Study, Sara A. El-Bahloul, Mohamed G. Elkhateeb

Mansoura Engineering Journal

Wire electrical discharge machining (WEDM) is a specific form of electrical discharge machining that employs a small diameter wire electrode to cut a narrow kerf in the workpiece. Since the wire deflection has a negative effect on the performed cutting, this research seeks to study the resultant wire deflection during WEDM of AISI 304 stainless steel. This study is performed with the help of three types of modeling; namely, mathematical modeling, experimental modeling, and thermo-mechanical finite element modeling. The mathematical modeling is performed to analyze the stresses and the wire lag, while the experimental modeling is achieved to observe the …

Me-Em Enewsbrief, June 2023, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical Engineering-Engineering Mechanics eNewsBrief

No abstract provided.

Synthesis And Evaluation Of Organic Additives For Copper Electroplating Of Interconnects, Yue-Hui Zhai, Yi-Xiao Peng, Yan Hong, Yuan-Ming Chen, Guo-Yun Zhou, Wei He, Peng-Ju Wang, Xian-Ming Chen, Chong Wang

Journal of Electrochemistry

Copper interconnects are essential to the functionality, performance, power efficiency, reliability, and fabrication yield of electronic devices. They are widely found in chips, packaging substrates and printed circuit boards, and are often produced by copper electroplating in an acidic aqueous solution. Organic additives play a decisive role in regulating copper deposition to fill microgrooves, and micro-vias to form fine lines and interlayer interconnects. Generally, an additive package consists of three components (brightener, suppressor, and leveler), which have a synergistic effect of super-filling on electroplating copper when the concentration ratio is appropriate. Many works of literature have discussed the mechanism of …

Effect Of Amine Additives On Thermal Runaway Inhibition Of Sic||Ncm811 Batteries, Bo-Wen Hou, Long He, Xu-Ning Feng, Wei-Feng Zhang, Li Wang, Xiang-Ming He

Journal of Electrochemistry

The high energy density of NCM batteries with high nickel content is a key advantage in replacing fossil fuels and promoting clean energy development, at the same time, is also a fundamental cause of serious safety hazards in batteries. Primary and secondary amines can lead to ring-opening polymerization of common ethylene carbonate electrolytes, resulting in an isolation layer between the cathode and the anode, and improving the thermal safety of the battery. In this work, the safety of batteries is considered both at the material level and at the cell level, based on the chemical reactions between amines and the …

Effects Of Traps On Photo-Induced Interfacial Charge Transfer Of Ag-Tio2: Photoelectrochemical, Electrochemical And Spectroscopic Characterizations, Zhi-Hao Liang, Jia-Zheng Wang, Dan Wang, Jian-Zhang Zhou, De-Yin Wu

Journal of Electrochemistry

In the field of metal-semiconductor composites based plasmon-mediated chemical reactions, a clear and in-depth understanding of charge transfer and recombination mechanisms is crucial for improving plasmonic photocatalytic efficiency. However, the plasmonic photocatalytic reactions at the solid-liquid interface of the electrochemical systems involve complex processes with multiple elementary steps, multiple time scales, and multiple controlling factors. Herein, the combination of photoelectrochemical and electrochemical as well as spectroscopic characterizations has been successfully used to study the effects of traps on the photo-induced interfacial charge transfer of silver-titanium dioxide (Ag-TiO₂). The results show that the increase of surface hydroxyl groups may …

Pulse Electroplating Of Nanotwinned Copper Using Mps-Peg Two-Additive System For Damascene Via Filling Process, Yu-Xi Wang, Li-Yin Gao, Yong-Qiang Wan, Zhe Li, Zhi-Quan Liu

Journal of Electrochemistry

High density nanotwinned copper films were pulse electroplated using an optimized electrolyte. In order to find out the influencing factors on the formation of nanotwins, series contents of MPS were added to the electrolyte during the pulse electroplating process. It was found that the copper films electroplated without MPS had large grains but a few nanotwins. And the grain size was about 0.9 μm on average, and the texture components of (110) and (111) crystal orientations were calculated as 49% and 27.8%, respectively. Differently, when 10 ppm MPS was added, the microstructure was changed to columnar grain with high density …

Hierarchical Based Classifcation Method Based On Fusion Ofgaussian Map Descriptors Foralzheimer Diagnosis Using T1‑Weighted Magnetic Resonance Imaging, Nourhan Zayed, Shereen E. Morsy, Inas A. Yassine

Mechanical Engineering

Alzheimer’s disease (AD) is considered one of the most spouting elderly diseases. In 2015, AD is reported the US’s sixth cause of death. Substantially, non-invasive imaging is widely employed to provide biomarkers supporting AD screening, diagnosis, and progression. In this study, Gaussian descriptors-based features are proposed to be efcient new biomarkers using Magnetic Resonance Imaging (MRI) T1-weighted images to diferentiate between Alzheimer’s disease (AD), Mild Cognitive Impairment (MCI), and Normal controls (NC). Several Gaussian map-based features are extracted such as Gaussian shape operator, Gaussian curvature, and mean curvature. The aforementioned features are then introduced to the Support Vector Machine (SVM). …

Failure Mode Effective Analysis In A Boiler Using Combination Of Event Tree And Fault Tree Analysis, Jayaprradap R, Udaya Prakash J

International Journal of Applied Research in Mechanical Engineering

Boilers are valued highly in many industrial industries and are expensive assets. In addition to their initial expense, they demand a large maintenance budget in order to guarantee output in respectable and safe working conditions. In order to avoid extreme repercussions, including the loss of lives, these assets must be carefully operated under experienced, well-trained supervision and subject to rigorous maintenance schedules and safety activities. However, this investigation is carried out with the help of the FMEA method, considering the previous literature's studies of boiler accidents in Asia so far. Phase I has detailed information about boilers and Asian boiler …

Evaluating Eeg–Emg Fusion-Based Classification As A Method For Improving Control Of Wearable Robotic Devices For Upper-Limb Rehabilitation, Jacob G. Tryon

Electronic Thesis and Dissertation Repository

Musculoskeletal disorders are the biggest cause of disability worldwide, and wearable mechatronic rehabilitation devices have been proposed for treatment. However, before widespread adoption, improvements in user control and system adaptability are required. User intention should be detected intuitively, and user-induced changes in system dynamics should be unobtrusively identified and corrected. Development often focuses on model-dependent nonlinear control theory, which is challenging to implement for wearable devices.

One alternative is to incorporate bioelectrical signal-based machine learning into the system, allowing for simpler controller designs to be augmented by supplemental brain (electroencephalography/EEG) and muscle (electromyography/EMG) information. To extract user intention better, sensor …

Stochastic Modeling Of Physical Drag Coefficient – Its Impact On Orbit Prediction And Space Traffic Management, Smriti Nandan Paul, Phillip Logan Sheridan, Richard J. Licata, Piyush M. Mehta

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ambitious satellite constellation projects by commercial entities and the ease of access to space in recent times have led to a dramatic proliferation of low-Earth space traffic. It jeopardizes space safety and long-term sustainability, necessitating better space domain awareness (SDA). Correct modeling of uncertainties in force models and orbital states, among other things, is an essential part of SDA. For objects in the low-Earth orbit (LEO) region, the uncertainty in the orbital dynamics mainly emanate from limited knowledge of the atmospheric drag-related parameters and variables. In this paper, which extends the work by Paul et al. (2021), we develop a …

Risk Maintenance Strategy In Blade Manufacturing Industry Machineries - By Using Applications Of Topsis Method, Poovanna Vivek Dev S, Sachin Salunkhe

International Journal of Applied Research in Mechanical Engineering

Regarding the capital and operating expenses of windmill turbines, blades are amongst the most vital parts. Those blades are made using conventional manufacturing methods such as deep groove machine, CNC Machine, foam slicing machine, glass layer machine, glass layer winding machine, balsa angle cutting machine, etc. In this research, TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) method is used to sort the machining methods that need to be handled very carefully according to risk and hazard in blade production. This research objective is to find the windmill blade design data, various production processes and its hazards, risks …

Improving Energy Efficiency Of School Buildings With Solar-Assisted Cooling For The Maldives, Ahmed Fathhee

Masters Theses

Anthropogenic activities are responsible for the impact of global climate change because of burning fossil fuels releasing harmful gases into the environment. As a result, the global temperature has risen about 1.18 °C since 1880, causing the global sea level to rise by 178 mm over the past century. This is a threat to countries that are closer to the ocean, especially the low-lying countries such as the Maldives. It is predicted if the sea level keeps rising, most of these islands could be below sea level by 2030.

The Maldives has a tropical climate requiring cooling to achieve thermal …

The Effects Of Hurricane Wind Field Characteristics On Wind Blade Loads, Michael S. Tsai

Masters Theses

Over recent years, offshore wind energy has been growing around the world. This necessitates placing wind turbines directly in or near the oceans where hurricanes can be. Previous research has suggested that hurricane wind veer and direction change can have adverse loading effects on the turbine. Such effects can create damage to the blade or worsen existing ones. Currently, there is no known design standard for addressing wind veer and direction change specifically from hurricanes. Quantifying the loading contribution from these phenomena is not abundant either.

This thesis seeks to demonstrate a proposed procedure for defining design veer profiles and …

Numerical Modeling And Simulation On Deformation And Failure Behaviors Of Polymeric Materials, Heng Feng

Electronic Thesis and Dissertation Repository

Featured by biocompatibility, high compliance and capacity in sustaining large deformation, dielectric elastomers (DEs) and hydrogels have gained extensive research popularity for their potential applications in the fields of soft robots, biomimetics, tissue engineering, drug delivery, and energy harvesting. The design of such soft and smart material-based devices and structures requires deep understanding and accurate simulation of their constitutive behaviors, which is challenged by their nonlinear material properties due to unique microstructures and multi-physics coupling. Meanwhile, in different application contexts, those structures are also susceptible to different failure modes, imposing further challenges in simulating and predicting their performance. To fulfill …

Additive Manufacturing Of High-Performance Nanolamellar Eutectic High-Entropy Alloys, Jie Ren

Doctoral Dissertations

Additive manufacturing, also called three-dimensional (3D) printing, is an emerging technology for printing net-shaped components layer by layer for applications in automotive, aerospace, biomedical and other industries. In addition to the vast design freedom offered by this approach, metal 3D printing via laser powder-bed fusion (L-PBF) involves large temperature gradients and rapid cooling and provides exciting opportunities for producing microstructures and mechanical properties beyond those achievable by conventional processing routes. Although these extreme printing conditions enable microstructural refinement to the nanoscale for achieving high strength. However, high-strength nanostructured alloys by laser additive manufacturing often suffer from limited ductility. Eutectic high-entropy …

Graphical Image Rendering: Modeling, Animation Of Facial Or Wild Images, Rohit Kaushik, Chirag Vashisht, Eva Kaushik

International Journal of Computer and Communication Technology

In this comparative study, we intend to analyse different methodologies to perform 3-Dimensional modeling and printing, by using raw images as input without any supervision by a human. Since the input consists of only raw images, the foundation of the methods is finding symmetry in images. But the images that seem symmetric are not symmetric due to the perspective effect and utterance of other factors. The method uses factors like depth, albedo, point of view, and lighting from the input image to formulate 3D shapes. A 3D template model with feature points is created, and by deforming the 3D template …

Influence Of Forming Forces On Torsional, Tensile, And Compressive Deformation Of Paperboard Packages, Arvo Niini, Panu Tanninen, Juha Varis, Ville Leminen

Journal of Applied Packaging Research

Paperboard packages were tested mechanically to investigate influence of forming forces on torsional, tensile, and compressive deformation. The packages were paperboard trays which were press formed with different pressing forces and blank holder forces. Deformation of the trays was observed with torsion, compression, and tensile tests. A statistical analysis of test results was conducted to derive optimal forming forces. Increased pressing force yielded desirable deformation characteristics with the trays. Blank holder force had largest impact on the compressive deformation. Interaction of the pressing force and the blank holder force influenced the torsional and the compressive deformation. The optimal forming forces …