Aerospace Engineering Commons^™

Flame Boundary Effects Of Hydrogen-Air Premixing, Alecson L. De Lima Junior

Honors Undergraduate Theses

The objective of this research was to investigate the reaction of hydrogen and heated air premixing when injected into a combusting ethylene-air crossflow, and to study the flame stabilization location with varying premixing levels. The main parameter of this investigation was the flame stabilization diagnosed through chemiluminescence, based on recorded equivalence ratio, temperature, and flame boundaries, and maintaining a constant air temperature, hydrogen and air mass flow, and momentum flux ratios. Testing was conducted at different ratios of hydrogen and air premixing achieved through alternating the distance between the point where hydrogen and air are mixed and the combusting crossflow. …

Potential Of Lidar And Hyperspectral Sensing For Overcoming Challenges In Current Maritime Ballast Tank Corrosion Inspection, Sergio Pallas Enguita, Jiajun Jiang, Chung-Hao Chen, Samuel Kovacic, Richard Lebel

Electrical & Computer Engineering Faculty Publications

Corrosion in maritime ballast tanks is a major driver of maintenance costs and operational risks for maritime assets. Inspections are hampered by complex geometries, hazardous conditions, and the limitations of conventional methods, particularly visual assessment, which struggles with subjectivity, accessibility, and early detection, especially under coatings. This paper critically examines these challenges and explores the potential of Light Detection and Ranging (LiDAR) and Hyperspectral Imaging (HSI) to form the basis of improved inspection approaches. We discuss LiDAR’s utility for accurate 3D mapping and providing a spatial framework and HSI’s potential for objective material identification and surface characterization based on spectral …

A Proximal Policy Optimization-Based Controller For Enhanced Power Sharing In Microgrids, Seyedmohammad Hasheminasab, Armin Lotfy, Mohamad Alzayed, Hicham Chaoui

Electrical & Computer Engineering Faculty Publications

This paper introduces a Proximal Policy Optimization (PPO)-based virtual impedance (VI) controller to enhance both power sharing and system response under disturbances in inverter-interfaced microgrids. Traditional droop control methods often face challenges due to variations in feeder impedance, which degrade performance. The proposed controller continuously updates its policy based on changes in the operating environment. The control problem is modeled as a Markov Decision Process (MDP), in which the state and action spaces are explicitly defined, and a carefully designed reward function, satisfying system criteria and constraints, guides the learning process toward achieving the desired transient and steady-state performance. By …

Qualitative Analysis Of The Circuits Of Autonomous Inverters With Shut-Off Valves, Shukhrat Badreddinovich Umarov

Technical science and innovation

The article presents the results of a qualitative analysis of circuits of autonomous current and voltage inverters with cut-off valves; the influence of the charge value of the switching capacitor in parallel and series equivalent circuits on the restoration of the switching properties of the thyristors of the inverter power circuit is studied. It is shown that due to the energy periodically accumulated in the inductive elements of the load, the voltage on the switching capacitor in the cut-off state is greater than in a conventional parallel autonomous current inverter. This circumstance ensures an increase in the switching stability of …

Theory And Algorithms To Learn, Propagate, And Exploit Uncertainty For Stochastic Optimal Control Of Dynamical Systems, Vignesh Sivaramakrishnan

Electrical and Computer Engineering ETDs

Non-Gaussian uncertainty frequently arises in learning and control problems involving stochastic dynamical systems, particularly in autonomous vehicles, UAVs, satellites, and robotics. In this dissertation, we propose a new framework that leverages characteristic functions that provides a frequency-domain representation of random variables. The dissertation is structured into three key areas. First, we address model-based stochastic optimal control for linear systems with non-Gaussian noise, demonstrating that characteristic functions can be used to enforce chance constraints and control systems toward desired distributions. Second, we explore data-driven stochastic control, utilizing empirical characteristic functions to handle systems with unknown disturbances. In addition, we derive several …

Performance Evaluation Of Routing Protocols And Ml-Based Enhancements For Uav-Assisted Post-Disaster Communication Networks, Prachi Choudhary

Doctoral Dissertations and Master's Theses

During natural disasters, the existing communication systems collapse, and the disaster-affected areas become disconnected without any means of exchanging information. The collapse of existing communication networks poses challenges for First-Responders (FRs) in locating survivors during Search and Rescue (SAR) operations and for survivors to communicate for emergency aid. To alleviate post-disaster consequences and save lives, Uncrewed Air Vehicles (UAVs), commonly known as drones, can be employed to establish adaptable and reliable emergency communication networks. UAVs offer portability and rapid deployment, making them effective in crises. This thesis presents two main contributions: 1) Evaluation and Comparison of Routing Protocol Performance: The …

Study Of The Synthesis Mechanism And Some Properties Of Oligomers Based On Epichlorohydrin And Diphenylguanidine, Rovshan Israilovich Ismailov, Normuhamad Edgarov, Alisher Israilovich Ismailov

Technical science and innovation

In this work, the synthesis and the scheme for obtaining an oligomer based on epiiodhydrin with diphenylguanidine were studied, the proportions of epiiodhydrin in the initial mixture, the yield of oligomers, and the reduced viscosity were studied. The results of spectroscopic and elemental analyzes are obtained, which show that changes in the ratio of monomers have almost no effect on the iodine content in the oligomer. This is apparently due to the fact that epiiodhydrin is much more active in reactions than amino compounds. By studying the degree of conversion on the viscosity of the oligomerization products, the effects on …

Justification Of The Effectiveness Of Software For The Design Of Open-Pit Mining, Tolib Olimovich Komilov, Bobirjon Nabijonovich Ashurov, Ulugbek Bakhtiyorovich Sattarov, Ma’Ruf Ixtiyorovich Karimov

Technical science and innovation

The article notes that the economic feasibility of implementing a project based on deposits directly affects the economy of the country and the region, as well as the construction of new facilities, the use of the most balanced approaches and design solutions in a complex will allow achieving the set goal of increasing production volumes and bringing the enterprise to a new level of development. In order to achieve the above goals, it has been proven with the implementation of investment projects using software for the design of open-pit mining, it is possible to further develop the region, agriculture with …

Study Of The Physical-Chemical Properties Of Chitosan Synthesized By The Cryogenic Method From Apis Mellifera Bees, Dilnoza Sohibovna Isomitdinova, Gulnora Akmalovna Ikhtiyarova, Jahongir Mustaqim O’G’Li Sharopov

Technical science and innovation

Chitosan was synthesized from Apis Mellifera dead bees by traditional and cryogenic methods, and the degree of deacetylation, viscosity, and molecular mass of the synthesized sample was studied. Chitosan was synthesized by deacetylation of chitin under cryogenic conditions. NaOH concentration 40%, temperature 90 ± 3 °C, time 120 min. The degree of deacetylation, and molecular mass was determined using an Ubbelode viscometer. DDA was determined by conductometric titration under standard conditions. The degree of deacetylation of Apis Mellifera chitosan was 87%. synthesized by cryogenic method DDA of chitosan was 83% synthesized by traditional method. Conducting the synthesis in liquid nitrogen …

Development Of A Universal Humidity Converter At Ultra High Frequency, Hulkar Asadullayevna Usmonova, Asadulla Turgunbayev

Technical science and innovation

The article proposes the and principle of operation of a universal primary measuring transducer of humidity at an ultra-high frequency with reciprocating motion along the vertical axis of rotation, which allows increasing the information redundancy of the primary measuring transducer (the influence of inhomogeneities, including humidity in the composition of the material, on the measurement result is averaged). The design of the primary measuring transducer under consideration provides for correction of the moisture measurement result by the mass (density) of the material, which will make it possible to carry out measurements without preliminary weighing the sample. The obtained results of …

Production Box Cost Estimating Relationships For Dod Avionics, Carla J. Cisneros, Edward D. White, Brandon M. Lucas, Jonathan D. Ritschel, Robert D. Fass, Shawn M. Valentine

Faculty Publications

The authors use historical information obtained from the Cost Assessment Data Enterprise to estimate recurring production unit cost for DoD avionics via cost estimating relationships (CERs). The specific modeled responses include mean unit cost, median unit cost, and the 100th production unit cost (T100) utilizing learning curve theory. For T100, the authors adopt both a multiplicative and an additive error for CER comparison. Recommended CERs consist of the mean unit cost and the T100 utilizing a multiplicative error. Moreover, results reveal that weight has a significant effect on cost as well as a potential underaccounting of real price change or …

Koopman-Based Modeling For Nonlinear Control Of Multirotor Uavs, Simone Martini

Electronic Theses and Dissertations

This PhD dissertation focuses on adopting the emerging Koopman Operator theory for modeling and nonlinear control of multirotor UAVs, focusing specifically on quadrotors for proof-of-concept demonstration purposes.

The Koopman Operator theory is based on the foundation that nonlinear dynamics in the state space may be represented as a linear evolution of some functions in the state space. Thus, using appropriately defined and possibly nonlinear functions of the state variables, called observables, as a new and maybe infinite set of coordinates that are referred to as lifted space, the original nonlinear dynamics appear to be linear. The implications of this theory …

Magnetic Sensor Compensation Utilizing Factor Graph Estimation, Frederic W. Lathrop, Clark N. Taylor, Aaron Nielsen

Faculty Publications

Recently, there has been significant interest in the ability to navigate without GPS using the magnetic anomaly field of the Earth (magnav). One of the key technical bottlenecks to achieving magnav is obtaining an accurate magnetic sensor calibration, taking into account own-ship and sensor effects. The Tolles-Lawson magnetic calibration method continues to be the industry standard and was developed when airborne magnetic survey aircraft were first employed over 70 years ago. In this paper, we present a magnetic calibration algorithm based on a factor graph optimization using inertial measurements as well as inputs from both a vector and scalar magnetometer. …

Ultrashort Pulsed Laser Treatment Is Effective At Sterilizing Metal Surfaces For Planetary Protection, Kaleb Mcquillan

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

To prevent forward contamination from microbes aboard spacecraft intended for exploration of solar system bodies there is a need for effective sterilization methods. However, current techniques are both time-consuming and expensive. For example, dry heat sterilization requires removal from the assembly site and several days of treatment. Furthermore, some components such as optics and electronics are not compatible with current sterilization techniques. In this thesis, a novel femtosecond laser surface processing technique for the rapid sterilization of spacecraft hardware is reported. Femtosecond lasers produce extremely high photon fluxes (10²⁹ photons/s*cm², ~0.03 J/cm²) in extremely short …

Development And Processing Of Shape Memory Polymer Composites (Smpcs) For Application In Structural Robotics And Robotic Sensors., Kavish Sudan

Electronic Theses and Dissertations

Shape Memory Polymers (SMPs) have attracted significant attention since their introduction in the 1980s due to their remarkable ability to regain their original shape from a temporarily deformed state when exposed to an external stimulus, typically heat. This shape memory effect, driven by thermal transitions such as the glass transition temperature (T_g) or melting temperature (T_m), has made SMPs highly attractive for applications in soft robotics, aerospace, and biomedical devices. However, SMPs face challenges such as limited mechanical strength, thermal stability, and electrical conductivity, which hinder their broader adoption in advanced applications. To address these challenges, …

Using A Neural Network To Remove Noise From Images, Anvar Asatilloyevich Ravshanov

Chemical Technology, Control and Management

This article proposes modern approaches to the problem of noise reduction in images using neural networks and also analyses the possibilities of noise reduction using neural networks. The convolutional neural network model and the Mediana, Sobel filter were considered for image denoising. The quality improvement of the trained neural network and the comparison with classical noise reduction methods have been carried out.

Board 125: Work In Progress: Faculty Experiences And Learning Through Oral-Assessment Implementation In Engineering Courses, Minju Kim, Carolyn L. Sandoval, Josephine Relaford-Doyle, Torus Washington Ii, Saharnaz Baghdadchi, Nathan Delson, Marko Lubarda, Alex M. Phan, Curt Schurgers, Huihui Qi

Psychology Faculty Articles and Research

This WIP qualitative research paper explores faculty experiences with implementing oral exams in high-enrollment undergraduate engineering courses at a research university. With a primary goal to improve conceptual mastery, as well as a desire to ensure academic integrity in the sudden move to remote instruction at the height of the pandemic, a group of faculty in Mechanical and Aerospace Engineering and Electrical and Computer Engineering departments implemented oral assessments in their own engineering courses across several quarters. They formed a research group with educational developers in a teaching and learning center on campus, and investigated the impact of oral assessments …

Interaction Of Particles With Plasma And Shock Produced By Pulsed Spark Discharge, Shomik Mukhopadhyay

Dissertations

Interactions of powders with high-temperature plasma and shockwaves occur in diverse scenarios, such as nuclear blasts, accidental industrial dust explosions, solid propellant combustion in explosive charges and when removing contaminants from surfaces. Electrostatic Discharge (ESD), known for generating shock and plasma, is a promising lab-scale technique for simulating these interactions. Studies with ESD involved placing powders near a spark-producing gap between electrodes and observing mechanical and chemical processes like particle motion and ignition. A limited range of spark conditions and material properties have been tested, which facilitated the development and validation of preliminary computational models describing this system. Significant gaps …

Regular Algorythms For Synthesis Of Optimal Control Systems For Dynamic Objects, Igamberdiyev Husan, Uktam Farkhodovich Mamirov, Xankeldiyeva Zebiniso

Technical science and innovation

The article presents algorithms for the synthesis of an optimal control system for dynamic objects. As a model, we consider a differential equation of a continuous one-dimensional system in the form of a state space, which has the properties of controllability and observability. The paper shows the need to use an observation device in order to assess how the properties of the controlled system change with the slightest change in the parameters of the control object, to assess the sensitivity of the system to these changes. When finding a solution to the equation formulated to find the parameters of the …

Studying The Production Of Nanocelluloses, Shohzodbek Abduvahobovich Rashidov, Elmurod Abduqodirovich Egamberdiev, Sadritdin Maxamatdinovich Turabdjanov

Technical science and innovation

Nanoscience is a broad field that includes nanophysics and nanochemistry. Nanotechnologies are aimed at obtaining nanoparticles with new properties and creating materials and devices based on them. This is one of the modern trends in the development of science in the 21st century.

Based on the study of information about nano-sized materials, the mechanisms of their production and changes in their properties, we will consider the technology for producing nanocellulose from organic substances, i.e. from cellulose. The article describes a technology that examines devices for producing nanocellulose and the principles of their operation, as well as a combined method of …

Comparative Analysis Of Cutting Forces In Axial-Compliant And Rigid Chamfering Tools, Sultonmurod Bekpulatovich Normatov, Oybek Tuyboyov, Azimjon Axror O'G'Li Pardayev, Alisher G‘Ayratjon Ogli Boratov, Shohjahon Tuxtasin Ogli Abdullayev

Technical science and innovation

This study delves into the analysis of cutting forces in axial-compliant systems, focusing specifically on the comparison between axially spring-compensated 90° conical tools and rigid chamfering tools. The research incorporates a predictive model for chamfer size calculation in the axially spring-compensated tools, verified through experimental tests on representative parts. The study aims to control chamfer size within tolerances by adjusting process conditions and optimizing processing efficiency. By exploring the fundamentals of the chamfering process, this research offers insights into breaking sharp edges on components with positional errors and shape deformations, with a particular emphasis on aero-engine casings. The integration of …

Enhancing Cybersecurity In Wireless Sensor Networks: Machine Learning, Blockchain And Future Perspectives, Ilemona Solomon Atawodi

Dissertations

Security in the Industrial Internet of Things encounters various security issues but the main issues can be broken down into three core issues: Availability, Integrity, and Confidentiality. Security challenges generally tend to be caused by a failure of the system in one of these areas or cause a failure in one of these areas. Therefore researching scalable solutions to these security issues is prudent to explore methods that could be applied to large-scale industrial IIoT with tens to hundreds of devices as well as small-scale systems on a tiny factory floor comprising of just a few devices. In our research, …

Reducing Glass Loss During Transportation And Storage, Abdulaziz Muzafarovich Qurbanov, Mirzaabdullayev Jaxongir Baxtiyorovich

Technical science and innovation

The article discusses the processes of transportation and storage of sheet glass in the production of protective glass for cars. The experience of organizing the transportation and storage of glass in developed countries of the world was analyzed in order to study the problems of losses of raw materials during the transportation and storage of laminated glass, as well as to develop and approve a regulatory and technical document. in this field. The supplies of various brands of polished laminated glass used in the production of protective glass for cars to Avtooina LLC from different addresses, from different manufacturers were …

Ferroresonance In Three-Phase Electrical Networks, Shavkat Ernstovich Begmatov

Technical science and innovation

Possible modes of ferroresonance in three-phase electric networks and analysis of substitution schemes where ferroresonance voltage increase is observed are considered. The most complete magnetization curve of the transformer core and the analysis of the generalized equivalent substitution scheme are presented, as a result of which more accurate formulas for determining the values of equivalent parameters of the electrical network and voltage transformer in ferroresonance mode are obtained. Factor of ferroresonance voltage increase is introduced, which determines ratio between amplitude values of transformer phase voltage and mains voltage. The method of determination of boundary conditions of steady ferroresonance voltage increase …

Main Prospects Of Natural Gas Purification Technologies From Acidic Compounds, Oybek Yusupdjanovich Aripdjanov, Diyora Zokhid Qizi Khayrullaeva, Jonibek Avazek Ogli Abdumuminov

Technical science and innovation

The article discusses the main prospects for the technology of purifying natural gas from acidic components and the problems of ensuring the purity of oil and gas products in accordance with state standards. An increase in the degree of purification from H₂S, CO₂, elemental sulfur, carbonyl sulfide, ethyl mercaptans (thiols), methyl mercaptan, carbon disulfide, sulfides, disulfides (dithioethers), thiophene, sulfoxides and sulfones is considered. Also, the physicochemical properties of the absorbent for the purification of sulfur compounds (generated during natural gas processing) are studied. Based on the study of various absorbents (ethanolamine (EA), methylethanolamine (MEA), diethanolamine (DEA), …

Use Of Mathematical Skills For Technical Condition Assessment Of Power Autotransformers, Dilafruz Rustamjon Qizi Abdullabekova, Nurali Berdiyorovich Pirmatov

Technical science and innovation

In this paper, we review innovative approaches to assess the technical condition of autotransformers using mathematical methods. The main purpose of these methods is to increase the efficiency of diagnostics and prevent possible failures in power systems. The developed mathematical expression is based on complex data analysis, application of statistical methods and machine learning technologies. This makes it possible to achieve more accurate and earlier detection of potential problems. As a result of these innovative approaches, the possibilities for early detection and prevention of faults are significantly increased. This is important for ensuring the smooth operation of power systems and …

Quantitative Assessment And Characterization Of Tool Wear Phenomena In Advanced Manufacturing Processes, Oybek Valijonovich Tuyboyov

Technical science and innovation

This paper explores the quantitative assessment and characterization of tool wear phenomena in advanced manufacturing processes, employing a multifaceted approach encompassing traditional measurements, image processing, machine learning, and predictive modeling. The study emphasizes the intricate dynamics of tool wear and its direct impact on cutting tool performance, addressing challenges in real-time monitoring and optimization of machining operations. Traditional methods like VBmax measurement are juxtaposed with advanced techniques such as the improved conditional generative adversarial net with a high-quality optimization algorithm (CGAN-HQOA), efficient channel attention destruction and construction learning (ECADCL), and shape descriptors based on contour, moments, orientations, and texture. Artificial …

Implementing A Solar Photovoltaic Station In Watering Systems Utilizing Complex Software, Akbarxon Sarvar O'G'Li Uroqov, Faxriddin Jaylovovich Nosirov, G'Olibjon Pardayevich Arzikulov, Zarina Amriddin Qizi Sayfutdinova

Technical science and innovation

This article explores the benefits of transitioning from traditional agricultural irrigation systems to more cost-effective alternatives powered by renewable energy sources. By integrating solar photovoltaic technology into irrigation processes, significant reductions in resource wastage, estimated at 45-50%, are achievable through the implementation of drip irrigation techniques. This results in enhanced agricultural productivity. Moreover, the utilization of solar panels in green zones mitigates surface temperature increases, contributing to a 2-5% boost in electricity production. Currently, irrigation facilities primarily rely on the main energy grid. However, transitioning to renewable energy sources decreases reliance on non-renewable fuels, reduces greenhouse gas emissions, and fosters …

Selective Oxidation Of Iron In Chalcopyrite For Enhanced Copper Recovery, Khojiakbar Shuxrat O'G'Li Sultonov, Shokhrukh Toshpulatovich Khojiev, Gulnoza Berdiyor Qizi Beknazarova, Malika Sayfullayevna Saidova

Technical science and innovation

This study explores the thermodynamic feasibility of selectively oxidizing iron contained in chalcopyrite mineral while preventing the oxidation of copper sulphide, with the ultimate goal of enhancing the copper concentration in the sulphide concentrate. A redox reaction in the solid phases between chalcopyrite and copper (I) oxide was constructed and subjected to thermodynamic analysis. The research identifies a crucial temperature range of 498-598 K (225-325 °C) as the most favourable for the redox reaction. The equilibrium constants at the selected optimal temperatures, 1.152 for chalcopyrite and 1.137 for copper (I) oxide, indicate that the redox reaction adheres to the expected …

Solving Water Resources Problems - Water Saving In The Republic Of Uzbekistan, Rustam Muxammatdjanovich Raximov

Technical science and innovation

In this article we will talk about the problems of water resources in the Republic of Uzbekistan. The problem of drinking water supply, solutions to provide drinking water to the population of Uzbekistan. The largest consumers of fresh water in Uzbekistan are farmers. Due to outdated infrastructure, 40% of water is wasted. Rising food prices and the risk of spreading disease are the first signs of water shortages that we may experience in the coming еars. Uzbekcosmos told how to solve the problem. Water is an invaluable resource used not only in the home, but also in the production and …