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Vibration Analysis And Condition Monitoring For Cement Mill (Case Of Hamma Bouziane-Constantine Cement Plant), Linda Bouyaya

Emirates Journal for Engineering Research

Monitoring and diagnosing damage in dynamic machinery is a growing area of interest in the cement industry. Indeed, industrial equipment is disrupted throughout its operation by malfunctions; especially in old age; which reduces their operating costs and availability. Therefore, the detection and identification of faults in industrial systems - diagnosis - is of capital importance for their operation and a major challenge for modern industry. Among the most used diagnostic techniques, we find spectral analysis, a condition-based maintenance tool, which is used to study the vibration signals of dynamic machines.

In this context, the objective of this work is the …

Boiling Crisis Is A Consequence Of Thermal Runaway In The Substrate Due To Degradation Of Nucleate Boiling Heat Transfer, Manohar Bongarala, Justin A. Weibel, Suresh V. Garimella

CTRC Research Publications

Chaotic bubble interactions during vigorous boiling have foiled attempts at an accurate mechanistic understanding of this important industrial transport process. Prediction of the boiling crisis (dryout) that occurs due to the spontaneous merger of bubbles into an insulating vapor film at critical heat flux remains an unsolved challenge. This work diagnoses the dryout process using synchronized high-resolution spatiotemporal heat flux and phase data, obtained via through-substrate infrared and visual inspection. We examine prevailing theories for the boiling crisis and provide evidence to rule out all but one. The boiling crisis is found to be a consequence of a peak in …

Modeling, Simulation, And Experimental Testing Of A Single-Legged Hopper, John Anthony Bennett

Master's Theses

Legged robots are well-suited for navigating unstructured terrain due to their ability to perform agile dynamic motions. Building on the efforts of Cal Poly's Legged Robotics Group, this project focuses on achieving stable forward hopping with a single legged robot.

A comprehensive model of leg hopping is formulated, with leg dynamics during flight and stance phases derived using Euler-Lagrange equations. During the stance phase, a spring-mass system models the leg-ground interaction. The touchdown and lift-off conditions are formulated mathematically, and state mappings between phases are determined via momentum conservation. A two-phase hybrid controller is designed, incorporating trajectory planning during flight …

Smart Zoning Control For Air Conditioning Systems, Octavio Gomes Diaz

Mechanical Engineering Theses

Nearly 45% of the energy consumed in residential buildings goes for Heating, Ventilation, and Air Conditioning (HVAC). Typical HVAC systems are mostly controlled by one thermostat that is usually located in the living room. This means that the HVAC system is running without consideration of the thermal conditions in the other rooms (zones), which might be colder (or warmer). Colder zones in the summer indicate that a lot of energy is wasted, and warmer zones mean that the HVAC system can’t produce a good comfort level. Therefore, zoning was introduced into relatively recent HVAC systems. Zoning in HVAC systems uses …

Fundamental Study Of Nonlinear Electrophoresis, Joseph Armakan Bentor

All Dissertations

Classical electrophoretic theory describes the linear response of particles suspended in Newtonian fluids under weak electric fields. When the electric field exceeds this weak limit, a nonlinear response arises due to non-uniform surface conduction over the curved particles. This nonlinear behavior introduces dependencies on fluid and particle properties not considered in the classical theory, offering potential advantages for microfluidic particle manipulation. While this phenomenon has been extensively studied theoretically and numerically in Newtonian fluids, experimental investigations have been relatively limited.

Fluid rheology can significantly alter particle dynamics under applied electric fields. Rheological properties like shear-thinning and elasticity which are not …

Linear And Nonlinear Topology Optimization With Morphing Beam Networks, Andrew S. Montalbano

All Dissertations

Topology optimization (TO) is an engineering design discipline dedicated to optimizing material distribution within a given domain. In traditional gradient-based topology optimization, the solid domain is discretized into small volumetric elements. Using finite element analysis (FEA) of the structure, the gradient of the objective function with respect to the design variables (the pseudo densities) is computed, and these design variables are updated iteratively until convergence is achieved. Although gradient-based TO methods are well-established, sensitivity analyses of objective functions and constraints can be both mathematically complex and computationally intensive. The nonconvex nature of most TO problems often complicates efficient convergence. Furthermore, …

Hybrid Physics-Infused Machine Learning Framework For Fault Diagnostics And Prognostics In Cyber-Physical System Of Diesel Engine, Shubhendu Kumar Singh

All Dissertations

Fault diagnosis is required to ensure the safe operation of various equipment and enables real-time monitoring of associated components. As a result, the demand for new cognitive fault diagnosis algorithms is the need of the hour. Existing deep learning algorithms can detect, classify, and isolate faults. Still, most depend solely on data availability and do not incorporate the system's underlying physics into their prediction. Therefore, the results generated by these fault-detecting algorithms sometimes need to make more sense and deliver when tested in actual operating conditions.

Similar to diagnosis, the fault prognosis of diesel engines is paramount in numerous industries. …

Experimental And Computational Investigation Of Green Laser Propagation Through Turbulent Medium In A Water Tank, Richard Owusu Adansi

Open Access Theses & Dissertations

Turbulence medium poses significant challenges to the propagation of laser beams, impacting applications such as free-space optical communication, remote sensing, and laser weapons systems. Therefore, comprehending and mitigating turbulence effects are vital for enhancing the performance of these systems. Analysis of a strong turbulence impact on electromagnetic wave propagation requires extensive knowledge of the Earth's atmospheric and Oceanic phenomena and Maxwell's electromagnetic theory of light as a propagating wave of electric and magnetic fields. Optical systems' propagation often encounters Strong Turbulence, causing interference and diffraction. Nonetheless, light propagation through randomly fluctuating media has been an exciting and active area of …

Smart Automatic Modal Hammer Predictor–Corrector Approach For Accurate Excitation Of Dynamical Systems, Mohammad Nasr

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This research introduces an innovative solution that revolutionizes the study of linear and nonlinear dynamical systems—a smart automatic modal hammer. With its affordability and intelligent capabilities, this automatic modal hammer becomes an invaluable tool for research and industry, enabling repeatable strikes with precise force control. This system's significance becomes particularly evident when studying nonlinear systems, which heavily rely on the excitation level for their dynamics. By offering a cost-effective design this proposed system proves to be robust in accelerating research on nonlinear dynamics, providing researchers with an efficient and accessible means to delve deeper into these complex systems. The proposed …

Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

It is well known that exotic properties and phenomena emerge as structural dimensions shrink to nanoscales. We self-assembled one-dimensional chains of gold nanoparticles in solution and quantified the growth process by monitoring the redshift of localized surface plasmon resonance (LSPR). Curiously, the redshift stopped while the chains continued to rearrange as manifested by gradual reduction in the LSPR peak. Using electromagnetic simulations, we quantitatively explained the phenomena as a rapid “addition-polymerization” followed by a sharp transition to “condensation-process.” Next, recognizing the significant electric field enhancement in the interparticle gap, a photoluminescent-active Eu³⁺ ion was used to probe Surface-Enhanced Photoluminescence …

On The Structure, Energy, And Segregation Behavior Of Grain Boundaries In Metallic Systems, Yasir Mahmood

All Dissertations

Nearly all structural metallic systems are multi-component polycrystalline aggregates; their microstructures are composed of crystalline grains that are internally joined at grain boundaries (GBs). This thesis focuses on GB structure, energy, and chemistry, as these greatly influence many material properties and processes, including boundary dynamics during processing treatments or under operating conditions.

Using atomistic simulations, we examine the impact of metastable GB structures on solute segregation. A wide range of GB geometries and metastable structures are used in our study. The Al-Mg alloy is used because it is of interest for light weighting. The atomistic simulation results are used to …

Convex Approach To Data-Driven Optimal Control With Safety Constraints Using Linear Transfer Operator, Joseph Raphel Moyalan

All Dissertations

This thesis is concerned with the data-driven solution to the optimal control problem with safety constraints for a class of control-affine nonlinear systems. Designing optimal control satisfying safety constraints is a problem of interest in various applications, including robotics, power systems, transportation networks, and manufacturing. This problem is known to be non-convex. One of this thesis's main contributions is providing a convex formulation to this non-convex problem. The second main contribution is providing a data-driven framework for solving the control problem with safety constraints. The linear operator theoretic framework involving Perron-Frobenius and Koopman operators provides the convex formulation and associated …

Review Of Fourth-Order Predictive Modeling And Illustrative Application To A Nuclear Reactor Benchmark. I. Typical High-Order Sensitivity And Uncertainty Analysis, Dan Gabriel Cacuci, Ruixian Fang

Faculty Publications

This work (in two parts) will review the recently developed predictive modeling methodology called “4th-BERRU-PM” and its applicability to nuclear energy systems as exemplified by an illustrative application to the Polyethylene-Reflected Plutonium (acronym: PERP) OECD/NEA reactor physics benchmark. The acronym 4th-BERRU-PM designates the “Fourth-Order Best-Estimate Results with Reduced Uncertainties Predictive Modeling” methodology, which uses the Maximum Entropy (MaxEnt) principle to incorporate fourth-order experimental and computational information, including fourth (and higher) order sensitivities of computed model responses to model parameters, while yielding best-estimate results with reduced uncertainties for the first fourth-order moments (mean values, covariance, skewness, and kurtosis) of the optimally …

Development Of A Passive Drag Reduction Modification For The 25° Ahmed Body Using Large Eddy Simulation, Skylar Polek

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the field of automotive aerodynamics, the Ahmed body is a generic vehicle-shaped bluff body which is meant to generalize the rear end of fastback and hatchback vehicles. Specifically, an Ahmed body with a rear slant angle of 25° has seen common use due to its resemblance of common rear windshield shapes as well as its notoriously complex wake structure. This research focuses on simulating the flow over a 25° in various situations with an ultimate goal of drag reduction. First, a simple benchmark of the k-ω shear stress transport (SST), large eddy simulation (LES) with the Smagorinsky-Lilly subgrid scale …

Hierarchy Of Exchange-Correlation Functionals In Computing Lattice Thermal Conductivities Of Rocksalt And Zinc-Blende Semiconductors, Jiacheng Wei, Zhonghao Xia, Yi Xia, Jiangang He

Mechanical and Materials Engineering Faculty Publications and Presentations

Lattice thermal conductivity (𝜅L) is a crucial characteristic of crystalline solids with significant implications for thermal management, energy conversion, and thermal barrier coating. The advancement of computational tools based on density functional theory (DFT) has enabled the effective utilization of phonon quasiparticle-based approaches to unravel the underlying physics of various crystalline systems. While the higher order of anharmonicity is commonly used for explaining extraordinary heat transfer behaviors in crystals, the impact of exchange-correlation (XC) functionals in DFT on describing anharmonicity has been largely overlooked. The XC functional is essential for determining the accuracy of DFT in describing interactions among electrons/ions …

Utilizing Bayesian Optimization In Technoeconomic Analyses For Integrated Energy Systems, Anthoney Griffith

All Graduate Theses and Dissertations, Fall 2023 to Present

Technoeconomic analysis is a key element in the study of integrated energy systems. The goal of this analysis is the sizing of technologies resulting in the best economic outcome for the system. The evaluation of this system involves sizing the components and simulating the resulting market to determine an outcome. This simulation incorporates multiple possible values of uncertain parameters like grid price and wind generation. This problem is currently approached with the gradient descent optimization method. An alternative approach, Bayesian optimization, sees success on simple problems of a similar nature to technoeconomic analyses. These results motivate applying Bayesian optimization as …

Development Of A High-Throughput Methodology For Vibration-Based Fatigue Tests, Brandon Alexander Furman

All Graduate Theses and Dissertations, Fall 2023 to Present

Global efforts towards the development of additively manufactured materials, biomaterials, metamaterials, self-healing materials, and composites have reached a staggering pace. With new materials being developed on a near-daily basis, it is more important than ever to be able to quickly and precisely quantify their mechanical performance. However, one of the most important mechanical properties, fatigue life, is notoriously time consuming to measure. Consequently, fatigue parameters are often calculated based on small sample sizes, resulting in high uncertainty of the measured parameters. In this dissertation a high-throughput approach to fatigue measurements is developed. This technique allows for multiple samples to accumulate …

Dynamic Modeling Of A Nuclear Integrated Energy System With Thermal Energy Storage And Hydrogen Production, Seth J. Dana

All Graduate Theses and Dissertations, Fall 2023 to Present

Historically, nuclear reactors have used water for cooling and moderating the nuclear reaction within the core. Advanced generation IV nuclear reactors currently under development are designed with different coolants which enable operation at higher temperatures. A higher operating temperature makes nuclear power suitable for co-located hydrogen production via high temperature electrolysis. Natrium, an advanced reactor design by TerraPower and GE Hitachi, combines a sodium fast reactor with molten salt thermal energy storage. The work presented in this thesis models and analyzes three Natrium systems which integrate hydrogen production with the Natrium nuclear power plant. The first two configurations focus on …

Understanding Ion Rejection Mechanism Of Freeze Desalination By Molecular Dynamics Simulation, Mahbuba Jannat

All Graduate Theses and Dissertations, Fall 2023 to Present

This study explores a method called freeze desalination, which uses the natural process of ice formation to remove salt from water at lower than freezing temperature of water, which is 235K (Freezing temperature of this water model is 249K), making it safe for potable water. Unlike traditional methods, freeze desalination can be more efficient and environmentally friendly, but how it rejects salt at the molecular level is not very clear to understand. Using molecular dynamics simulation, this research aims to uncover the details of this process. We focused on understanding how water molecules interact with salt ions during freezing. Our …

The Role Of Sensing Modalities In Shaping Collective Motion And Group Behavior, Poorendra P. Ramlall

Doctoral Dissertations and Master's Theses

Collective behavior refers to the coordinated movements that emerge from simple interactions between individuals within a group. Traditionally, researchers have modeled these interactions assuming individuals can sense their surroundings in all directions, like having eyes all around their heads. While this is a useful simplification, it does not capture the diverse ways animals actually sense the world. In this thesis, we take inspiration from the natural world, particularly from animals like bats and dolphins that use a combination of hearing and sight to navigate their environments. We explore how combining these sensory cues in a three-dimensional space affects the way …

Pyrolysis Kinetics Of Spirulina Platensis And Non-Condensable Gas Product Distribution In A Fixed-Bed Reactor, Ahmad Yusril Aminullah, Sukarni Sukarni, Retno Wulandari, Muhammad Shahbaz

Journal of Mechanical Engineering Science and Technology (JMEST)

Energy is a fundamental factor for civilization development and sustainability. However, energy sources are dominated by non-renewable fractions, such as fossil fuels. Renewable biomass is projected to be a future fuel source. Spirulina platensis (SP) has numerous advantages compared to other biomass, and it is considered 3rd generation biomass that does not interfere with food and land usage and has a relatively low main decomposition temperature at 325.7℃. Thermogravimetric analysis (TGA) was conducted to observe SP kinetics parameters, especially activation energy. Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), and Starink iso-conversional methods reveal that SP has an activation energy of 152.33, 154.56, and …

Durability Of Thermoplastic Polyurethane Round Belt Joint With Variations In Heating Methods And Cutting Shapes, Achmad Sabilarrosyad Prawiro Kusumo, Anggit Murdani

Journal of Mechanical Engineering Science and Technology (JMEST)

Thermoplastic polyurethane round belts are widely used for conveyors in various industries, particularly in the food and beverage industry, due to their flexible and abrasion-resistant characteristics. These belts are also popular in manufacturing industries because of their ease of joint. However, a common issue arises when the conveyor belt breaks during the production process. This problem can be attributed to the lack of parameters in the belt joining process at companies. Operators do not have a standard parameter for the joining process. When there is an improper joining operation of an operator, the conveyor belt could fail earlier than the …

Heuristic Approach To Comparing The Environmental Impacts Of Carbon Nanotube Production Methods, Ahmad Atif Fikri, Irham Fadlika, Albarrobi Nabila Saeful, Krisna Dwipa Muhdi, Daniel Febrian Pratama, Nasir Garba Bello

Journal of Mechanical Engineering Science and Technology (JMEST)

Carbon Nanotubes (CNTs) production so far has its own advantages and disadvantages. Some methods that can be used in producing CNTs are chemical vapor deposition (CVD), laser ablation, and arc discharge. The three methods have their own requirements, this causes different environmental impacts on each method. Studies into the environmental impact of the CNTs production process found that during thermal pretreatment of the reactant gas, more than 45 by-products were formed, including methane, volatile organic compounds, and polycyclic aromatic hydrocarbons. Calculating the environmental impact of CNTs production method often has challenges in implementation, because each production process has different systems …

Experimental Study On The Effect Of Micro Concentrations Of Hybrid Nanofluids Through Microchannel Heat Sinks, Mohamed Salaheldin Elsherbiny, Moustafa Ali, Moatsem Shahin, Mahmoud El-Kady

Renewable Mechanical Energy

The current study examines the convective heat transfer coefficient experimentally. It assesses the performance of Al2O3, CuO, ZnO, and Ag/ distilled water nanofluids up to a tetra level of hybridization utilized in microprocessor cooling systems equipped with MCHS. An equal ratio of 50%, 33.3%, and 25% for di-, tri-, and tetra-nanofluids, respectively, with a focus on micro-volume fraction 0.025% and comparing it with 0.05%. Operating conditions were as follows: heat loading from 136.4 up to 196.4 watts; and flow rate from 0.35 up to 0.5 LPM. The findings showed that all types of mono nanofluids showed an increase in Nu …

Activity: Students Find Conceptual Errors In Ai Output, Janie Brennan

Generative AI Teaching Activities

Instructor asks ChatGPT questions related to a key concept to find one where ChatGPT has conceptual errors. Ask students to find the errors and explain them.

Corrigendum To “Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis”

Journal of Marine Science and Technology–Taiwan

No abstract provided.

A Case Study On Optimizing Industrial Air Conditioning With Thermal Solar Energy In Egypt, Tamer Adel Mohamed, Hesham Safwat, Mohammed A. Ebaid

Mechanical Engineering

This study investigates the feasibility of implementing a solar-assisted adsorption chiller in an industrial building at the Oriental Weavers International factory located in 10th of Ramadan City, Cairo, Egypt. The objective is to replace an inefficient split air conditioning system currently used to cool the Jacquard units during carpet manufacturing. The research begins by analyzing the performance of the existing cooling system to establish a baseline. It then explores the potential energy savings achievable by replacing the current system with a solar-assisted adsorption chiller. The existing oversized boiler will serve as an auxiliary heater for the new system. TRNSYS simulation …

Analysis Of The Potential For Enhancing The Efficiency Of A Floating Photovoltaic (Fpv) System, How-Ping Wu, Ching-Yi Tseng, Chuan-Chung Jen, Yuan-Ching Chiang, Sih-Li Chen

Journal of Marine Science and Technology–Taiwan

This study examined the power generation capabilities of FPV systems and the advantages of employing active cooling on floating solar panels. Floating solar panels exhibit improved efficiency due to operating at lower temperatures facilitated by the cooling effect of water evaporation. Additionally, the high availability of water renders the application of the active cooling technique economically viable. This study developed a comprehensive simulation of a floating solar system, integrating a mathematical model to validate experimental findings and a temperature model derived from an energy equation specific to floating solar panels. This model calculates the heat transfer among the three different …

Investigating The Fatigue Life Of Asymmetric And Novel Helical Gear Drives, Rajesh S

Theses and Dissertations

The present research work investigates the contact and bending fatigue life of asymmetric helical gear and novel helical gear based on the finite element analysis. In the first phase, the contact and bending fatigue life of the asymmetric helical gear drives is estimated based on the strain life approach.

Further, a parametric study is carried out to investigate the influence of important helical gear parameters such as module, pressure angle, helix angle, gear ratio, teeth number and face width on contact and bending fatigue life of asymmetric helical gear drives. It is noted that the asymmetric helical gear shows a …

Performance And Enhancement Evaluation Of A Solar Still By Using Spraying Technology, Mahmoud Mohamed Dewedar, Yasser A. F. El-Samadony, Alsayed Alsaeed Mohamed, Ahmed Ibrahim Abdo

Journal of Engineering Research

The current experimental investigation uses the water spraying approach to increase the productivity and efficiency of pyramid solar still. The design, construction, and testing of a traditional and modified small-scale pyramid solar still were conducted under identical meteorological conditions as in Tanta City, Egypt (30° 47' N, 31°E). One of the modifications is that heated sheet metal will occasionally be sprayed with salted water. We looked into how the modified solar still's (MPSS) performance characteristics were affected by solar radiation, water depth, and sheet metal-specified temperature. Measurements were made of the saline water temperature, glass temperature, spraying flow rate, and …