Dynamics and Dynamical Systems Commons^™

Integrating Gis With Interim Payment Valuation In Road Construction Projects: A Conceptual Framework, Abdulrahman I. Iro, Juma M. Matindana, Julian Ijumulana

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Interim Payment Valuation is a critical process in road construction contract administration, yet conventional valuation practices remain heavily dependent on manual measurements, fragmented documentation, spreadsheets, and professional judgement. These limitations can affect measurement accuracy, transparency, traceability, and the timeliness of payment certification. Although Geographic Information Systems have increasingly been applied to construction planning, quantity measurement, progress monitoring, infrastructure management, and decision support, their integration with contractual and financial processes for interim payment valuation remains insufficiently explored. This study therefore develops a conceptual framework for integrating GIS with Interim Payment Valuation in road construction projects. A PRISMA-guided structured literature review …

Voltage-Related Power Quality Issues And Impacts On Distribution Networks With Sensitive Loads - A Review, Godwin Elinazi Mnkeni, Jackson Justo, Aviti Thadei Mushi, Bakari M. M. Mwinyiwiwa

Tanzania Journal of Engineering and Technology (TJET)

Voltage disturbances are the most important power quality (PQ) complications that customers and power utilities face in this smart era. The growing adoption of sophisticated electronic equipment and integration of renewable energy sources (RES) into power grids has increased the susceptibility of power distribution networks (PDNs) to voltage sags, swells, interruptions, flicker, and voltage imbalance. These disturbances, mainly caused by upstream faults, switching operations, and RES integration, compromise voltage PQ and system reliability. Consequently, they accelerate equipment degradation, increase electronic waste (e-waste), raise reactive power demand and maintenance costs, increase power losses, and impose substantial economic losses on customers and …

Influence Of Infill Geometry On The Vibrational Behavior Of 3d-Printed Cantilever Beams, Owen Maute

Discovery Day - Daytona Beach

Vibration and damping are important considerations in many engineering structures, especially as additive manufacturing becomes more widely used in functional mechanical components. This project investigates how the internal structure of 3D-printed parts affects their vibrational behavior. A series of cantilever beams with identical outer dimensions will be designed and manufactured using a 3D printer with PLA filament, since PLA is one of the most commonly used materials in consumer and prototyping-level additive manufacturing. The study will examine five different infill patterns at three different infill densities, producing multiple beam configurations that vary only in their internal geometry. In addition to …

Mechanical Vibrations And Damping, Axon Deadrick, Will Standish, Tanay Agarwal

Discovery Day - Daytona Beach

Mechanical vibrations occur in many engineering systems and can be described using second-order differential equations. In this project, the motion of vibrating systems is studied using the mass–spring model. The focus is on three types of oscillations: free vibrations, dampened vibrations, and forced oscillations. Free vibration describes how a system moves when it is displaced and then released without any external force. Damped vibration includes effects such as friction or resistance that cause the motion to gradually decrease over time. Forced oscillations occur when an external force acts on the system and continuously drives the motion. This project also examines …

Integrated Power, Energy, And Thermal Management For Autonomous Hybrid Off-Road Vehicles: Multi-Timescale Modeling, Predictive Control, And Resilient Thermal Design, Anirudh Sundar

All Dissertations

Electrification and autonomy are increasingly important for off-road vehicles operating in construction, agriculture, mining, defense, and other demanding environments. These platforms must deliver high tractive power under unstructured terrain, harsh ambient conditions, low-speed operation, and large auxiliary loads. While hybrid and electrified powertrains offer improved efficiency, mobility, and auxiliary power capability, they also introduce significant challenges in managing tightly coupled power, energy, and thermal subsystems. In particular, lithium-ion batteries, power electronics, electric machines, and internal combustion engine-generator systems operate across different temperature limits and timescales, requiring coordinated management to ensure efficiency, durability, and safe operation. This dissertation develops modeling, planning, …

Hybrid Solar - Coal Thermal Energy System For Industrial Process Heat At Sayona Drinks Limited In Tanzania, Santos Kihwele, Elisha D. Bitesigirwe

Tanzania Journal of Engineering and Technology (TJET)

Over the past two decades, global efforts to mitigate pollution from conventional energy sources have intensified, with coal remaining a major contributor to carbon emissions. While fossil fuels cannot be eliminated from thermal generation in manufacturing industries, particularly in middle‑income countries such as Tanzania, they continue to dominate as the primary energy source. Industries including food and beverage, paper, textile, paints, chemicals, and pharmaceuticals require substantial thermal energy for heating and drying, and typically rely on coal and natural gas.This study introduces a unique application of a parabolic trough solar thermal system with integrated thermal energy storage, specifically tailored to …

Cal Poly Fluid Powered Vehicle Challenge 2025/2026, Ethan Malachi Nejame Zeiset, Christian Anthony Cuamani, Daniel Chacon-Bizarro, Marcus Minera, Bradley Hansell

Mechanical Engineering

In this Final Design Report, the Cal Poly Fluid Power Vehicle Challenge Contending Team competed in Sun Hydraulics’ 2026 Fluid Powered Vehicle Challenge. The objective of the competition is to expose college students to the fluid power sector, the “hidden giant” of the engineering industry. Specifically, student teams are tasked with the development of a human-powered, fluid-driven vehicle for use in various competitive settings. The team prioritized the optimization of an existing prototype for simplicity, ease of maintenance, and reliability during the competition. The existing prototype exhibited issues related to the main frame’s deflection under load, a lack of gear …

Computational Insights Into Nucleosome Dynamics In Epigenetics Using Molecular Dynamics Simulations, Rutika Patel

Dissertations, Theses, and Capstone Projects

Nucleosome core particles (NCP) are the building blocks that form a highly organized and compact chromatin structure. Nucleosomes package DNA in the nucleus of eukaryotic cells. The NCP consists of about 147 base pairs of DNA wrapped around the histone octamer, with 1.65 superhelical turns in a left-handed manner. The histone octamer is composed of two copies of H3, H4, H2A, and H2B. Together with histone H1 and linker DNA, they further assemble into a higher-order chromatin structure. The nucleosome complex is stabilized by electrostatic interactions between positively charged histone residues and the negatively charged DNA backbone. To effectively access …

An Analytical Framework For Quantifying Urban And Community Resilience To Natural Hazards From Cell-Phone Gps-Location And Traffic-Flow Data, Georgios Chatzikyriakidis

Civil and Environmental Engineering Theses and Dissertations

Urban areas are increasingly exposed to natural hazards while accommodating a growing share of the global population, yet a consistent science-based framework for quantifying urban and community resilience remains lacking. This dissertation develops a physics-based analytical framework grounded in statistical mechanics and the quantitative theory of Brownian motion. A city is conceptualized as a complex medium in which citizens move analogously to Brownian particles within a viscoelastic environment, influenced by socioeconomic interactions and infrastructure functionality.

A central premise is that urban resilience, interpreted as engineering resilience (an outcome), can be quantified through a single metric: the mean-square displacement MSD=⟨r²(t)⟩, of …

Versatile Exoskeleton Control Paradigms For Agile Human Locomotion: Task-Agnostic And Stability-Augmented Assistance, Miao Yu

All Dissertations

Lower-limb exoskeletons have shown great potential for assisting human locomotion, but designing controllers that provide assistance across diverse locomotor tasks and under external perturbations remains a major challenge. Many existing controllers for steady-state walking rely on pre-defined reference trajectories, which constrain voluntary human motion and limit adaptability across tasks. Moreover, they usually assume stable walking, while their performance under unstable conditions remains largely unexplored. In addition, existing gait stability augmentation controllers are often reactive rather than proactive to unstable conditions. In this dissertation, we propose control frameworks that preserve voluntary human motion while addressing two major challenges: providing task-agnostic assistance …

Identification Of Thruster Faults In Underwater Vehicles By Using Custom Encodings In Spiking Neural Networks, Donovan Gegg

LSU Master's Theses

Autonomous Underwater Vehicles (AUVs) are untethered robotic platforms used for tasks such as seafloor mapping, infrastructure inspection, and environmental monitoring. Recent technological advances have produced smaller, more affordable platforms, broadening access to research teams and small companies alike. This miniaturization comes at the cost of them handling drawbacks associated with a more compact machine such as reduced battery capacity as well as limited processing and sensing capabilities. These constraints make small-sized marine vehicle’s reliability critical as they can cause malfunctions, making the loss of a vehicle more likely. Actuator faults are particularly consequential as unintended and unstable control in an …

Swarm Of One: Self-Organization In Multicellular Robots, Trevor Riley Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Designing robots traditionally relies on centralized, top-down methods that constrain adaptability and resiliency, producing systems optimized for specific tasks. However, such systems often fail in complex environments, such as extraterrestrial, disaster, or natural settings, where designers cannot foresee every scenario a robot may encounter. Achieving autonomy in these contexts requires robots that are resilient and capable of adapting to the unknown. Multicellular organisms exhibit this adaptability through self-organization, where complex structures and behaviors emerge from local interactions among their cells. Such organisms can be viewed simultaneously as a single entity and a swarm of cooperating cells, i.e., a Swarm-of-One.

This …

Investigating The Harmonic Content Of A Pwm Inverter With Varying Modulation Index, Peter Makolo

Tanzania Journal of Engineering and Technology (TJET)

Photovoltaic energy is a clean and endless vital renewable energy. In order to generate electricity from solar energy an inverter is required to transform the direct current into alternating current. Also, with the emerging of new ultra-high voltage direct current transmission technology, the rectification and inverters play a great role. Most three-phase two-level inverters draw harmonics that cause heat dissipation, waveform distortions hence affect the electrical loads. Knowing that Total Harmonic Distortion content of voltage source inverter is important and must be within the allowable range. Several schemes are suggested to mitigate the distortion in order to produce as much …

A Polar Turbulence Invariant Map With Applicability To Realisable Machine Learning Turbulence Models, James G. Wnek, Christopher Schrock, Eric M. Wolf, Mitch Wolff

Mechanical and Materials Engineering Faculty Publications

Invariant maps are a useful tool for turbulence modelling, and the rapid growth of machine learning-based turbulence modelling research has led to renewed interest in them. They allow different turbulent states to be visualised in an interpretable manner and provide a mathematical framework to analyse or enforce realisability. Current invariant maps, however, are limited in machine learning models by the need for costly coordinate transformations and eigendecomposition at each point in the flow field. This paper introduces a new polar invariant map based on an angle that parametrises the relationship of the principal anisotropic stresses, and a scalar that describes …

Implementation Of Reliability Centered Maintenance On Crude Booster Pump, Dzulfikar Ali Hafizh, Maya Agustianingrum Putri St., Ph.D., D. Rizal, Adzra Qanita

Journal of Materials Exploration and Findings

Crude oil booster pump is one of the critical equipment in oil refinery operations. In aging plants that have been operating for more than 25 years, where reliability and maintenance issues on equipment often cause operational disruptions and even unplanned shutdowns. This study aims to develop a structured reliability-centered maintenance (RCM) strategy for crsude oil booster pump systems that is also in line with the principles of asset integrity management system (AIMS). This methodology follows the RCM II approach, starting with system function analysis, failure mode identification, and criticality assessment through Failure Mode, Effect, and Criticality Analysis (FMECA) to determine …

Towards Metrology 4.0 In Developing Countries’ Manufacturing Industries, Jailos Nzumile

Tanzania Journal of Engineering and Technology (TJET)

A systematic literature review was conducted to unveil the status of the digital transformation of metrology in developing countries, as they are lagging in utilising fourth industrial revolution (IR4.0) technologies to transform manufacturing industries. A PRISMA technique was employed using various keywords to identify, screen, and select the relevant literature. Forty publications were selected for the review, mainly discussing IR 4.0 technologies in metrological operations. The results indicate that the digital transformation of metrology has yet to be initiated in developing countries. However, the employment of IR4.0 technologies in advancing metrological operations in manufacturing industries is mostly discussed in the …

Potential Use Of Pump As Turbine Coupled To Self-Excited Induction Generator For Micro-Hydro Cooking And Cooling Applications, Emanuel J. Nyirenda

Tanzania Journal of Engineering and Technology (TJET)

Clean cooking and efficient cooling in developing countries have recently become areas of great focus. Further, the environmental impact of flooding in high-capacity hydroelectric plants has become a major concern. As a result, there is growing emphasis on developing sustainable and decentralized energy solutions, focusing on the potential of micro-hydro systems, especially in rural and remote areas. Although there are several alternative energy generation methods, their application is not straightforward. One of the latest technologies under research is using pumps as turbines coupled to an induction generator. This paper explores through a rigorous experimental approach the possibility of using a …

Energy Optimal Coverage Motion Trajectory Generation Using A Fourth-Order Motion Profile, Mathias Halinga

Tanzania Journal of Engineering and Technology (TJET)

Industrial machines are widely used in manufacturing sector to manufacture several products to meet customer demands. Most of these industries runs all the time throughout a day leading to high operating cost. To cut costs and satisfy customer demand for precise products, industrial machines’ motion generation is important in improving machine motion precision while using less energy. This study presents a coverage motion energy optimization which is generated by linear interpolation of each segment described by the fourth-order motion profile. The phase changes in the profile are attained with continuity of machine kinematic limits jerk, acceleration, and velocity, which are …

Calibration Of Measurement Tools In The Experimental Test Rig For Hydropower Performance Evaluation, Ombeni J. Mdee

Tanzania Journal of Engineering and Technology (TJET)

The demonstration of a typical hydropower plant requires the development of a test rig with the installation of tools to measure the performance parameters. The measurement tools require a calibration process to improve the quality of recorded data. This study involved the calibration of traditional and automated measurement tools connected to the hydropower test rig through an Arduino microprocessor. The automated measurement tools included a pressure transducer, flow meter, digital tachometer, and torque transducer, while traditional measurement tools, including a pressure gauge, concrete water tank, contact tachometer, and force lever arm balance, were connected in the same test rig during …

Data-Driven Constrained Control, Ali Kashani

Mechanical Engineering ETDs

Ensuring safety is a fundamental challenge. Traditional methods often rely on precise mathematical models, which are difficult, impractical, or costly to obtain for real-world systems with complex, nonlinear dynamics. This dissertation develops direct data-driven control approaches that enable safe and efficient operation of nonlinear systems without requiring explicit models or performing system identification. This effort leverages machine learning, optimization, and control theory to bridge theoretical rigor and practical applicability. Deterministic guarantees are provided based on the Lipschitz continuity of the system, and probabilistic guarantees through scenario optimization. The computation of safe sets is performed using one-shot approaches with broad neural …

Design And Optimization Of Aquaculture Gear: Development Of A Cage-Integrated Reeling Mechanism For Oyster Farming, Felicity Bryant

Honors Theses

This project encompasses the design, fabrication, and testing of a cage-integrated reeling system aimed at reducing the physical labor required in oyster aquaculture at Bama Bay Oyster Farm, the last operational oyster farm in Mobile Bay. The proposed system includes two primary components: lightweight, modular oyster cages and a dual-winch reeling device for automated retrieval. Three cage prototypes—rectangular, oval, and hexagonal—were evaluated for structural performance and fabrication feasibility. The oval design was ultimately excluded due to practical fabrication limitations. The rectangular and hexagonal designs were fabricated using recycled materials and tested under the most extreme environmental conditions derived from years …

Application Of Artificial Neural Network Models For Predicting Diesel And Petrol Prices In The Geographically Sparsed Regions In Tanzania, John M. Kafuku

Tanzania Journal of Engineering and Technology (TJET)

Fuel consumption in Tanzania, mainly diesel and petrol, accounts for 82 percent of the energy consumption in the country, with significant price volatility affecting market stability, availability of fuel, and investment decisions. This study uses an artificial neural network (ANN) with a backpropagating algorithm to predict fuel prices in four regions of Tanzania. Key input parameters include the currency inflation rate (CIR), the petrol fuel inventory (PFI), the diesel fuel inventory (DFI), and the fuel transport costs (FTC). The study selected the 6-10-10-2 ANN structures for Sumbawanga-Rukwa, Mpanda-Katavi, and Mbeya-Mbeya as well as 6-10-9-2 for the Songea-Ruvuma region. The results …

Clustering Mini-Grids To Enhance Power Systems Reliability In Distributed Generation, Santos Kihwele

Tanzania Journal of Engineering and Technology (TJET)

This study investigates the effectiveness of clustering mini-grids as a method to improve the reliability and operational stability of distributed generation systems in remote areas, particularly where renewable energy sources are predominant. As renewable resources like solar and wind are increasingly integrated into mini-grids, these systems face various challenges, particularly in maintaining stable voltage and frequency across interconnected networks. Such issues are compounded by the intermittent nature of renewable energy sources and the lack of extensive communication infrastructure in rural or resource-constrained settings. To address these control challenges, this study applies droop control techniques to two mini-grids in Uganda, utilizing …

Heavy Metals Pollution In Roadside Ecosystems, Lilian Matafu

Tanzania Journal of Engineering and Technology (TJET)

Heavy metals refer to metallic elements that are characterized by having a relatively high density and they are toxic or poisonous even at low concentration. They are environmental pollutant owing to toxicity and longevity in atmosphere and ability to accumulate in living things via bioaccumulation. They tend to enter in different system such as food chain. Analyses of water, soil sediment and the surrounding growing plants (Cynodon dactylon and Cyperus species) for selected heavy metals (Cd, Pb, Zn and Cu) were conducted on a roadside pond located at Boko MSB, Dar es Salaam. Pond water, soil sediments and plant samples …

Assessment Of Wind Speed Characteristics And Available Wind Power Potential For Electricity Generation In Tanzania, Mwingereza John Kumwenda

Tanzania Journal of Engineering and Technology (TJET)

The energy demand and its associated crises are attracting significant attention due to population increase and economic growth especially in developing countries. Fossil fuel-based energy source stand as a prominent anthropogenic resource but they are accompanied with increased carbon emissions and heightened environmental concerns. Renewable energy sources such as wind energy can offers a lot of potential for sustainable growth in the energy sector of developing nations like Tanzania. Thus, this work investigated wind speed characteristics and available wind power potential in six selected regions in Tanzania with different topographical features for future electricity generation. The data of the wind …

3d Printed Microfluidic Fabrication Methodology, Characterization, Mechanical Design, And Applications In Electrostatic Artificial Muscles And Benthic Microbial Fuel Cells, Terak B. Hornik

Master's Theses

The fabrication of microfluidic devices often requires specialized methods. The development of these methods requires careful characterization and understanding of the processes involved. Using primarily PolyJet 3D printing technology, microfluidics offers a wide scope of applications such as microfluidic benthic microbial fuel cells (MBMFCs) and electrostatic artificial muscles. MBMFCs benefit from the confinement of the microbes resulting in close proximity between the electrode and the organisms. Using a modular design called the Sponge, assembly and upscaling is possible. Electrostatic artificial muscles benefit from a microfluidic approach due to the non-linearity of electrostatic attraction creating disproportionate benefits when miniaturized. When designed …

Collision Dynamics Of Compound Droplets In Microchannels: A Combined Numerical And Data-Driven Study, S M Abdullah Al Mamun

Dissertations

Understanding and predicting the hydrodynamic interactions of micron-scale droplets is crucial in a wide range of industrial and real-life applications, including microfluidics, pharmaceutics, drug delivery, food science, and enhanced oil recovery. These multi-phase and multi-scale phenomena are further complicated by the presence of core droplets of an immiscible fluid within shell droplets, known as compound droplets. The collisions and interactions of droplets in emulsions are influenced by various physical and geometric parameters, leading to distinct rheological and dynamic responses. This research employs numerical methods for a systematic parametric study of both simple and compound droplet pair collisions under confined shear …

Endwall Contouring For Lowering The Thermal Load And Augmenting The Turbine Efficiency, Arjun Kozhikkatil Sunil, Tide Porathoor Sunny

Makara Journal of Technology

Endwall contouring having significance in delineating ideal endwalls competent in thermal load depletion is the focus of this study. We have successfully utilized non-axisymmetric contoured endwalls to enhance turbine performance by controlling the secondary flow characteristics in a blade passage through steady-state numerical hydrodynamics. The supreme endwall pattern could lower the gross pressure loss at the design stage and is related to the size of the top-loss location being productively lowered. The selective numerical shape change using multi-objective optimization at the most prominent locations resulted in contoured endwall geometry and a considerable reduction of thermal exchange in the vane passage …

Capacitive Sensors With Ultra-Small Capacitance For Smart Measurement And Control Systems, Rustam Baratov, Farrux Jabbor O'G'Li Ko'charov

Chemical Technology, Control and Management

This article discusses methods of low capacitance measurement of capacitive sensors. The results of the study of the amplitude-frequency (AF) and phase-frequency (PF) response of measurement circuits of capacitive sensors for low capacitances measurement, consisting of RC - differentiating elements are presented. The input and output parameters of the differentiating circuit and the complex transfer function are analyzed. The research results show that low capacitances measurement by measuring the rectangular pulses duration is the most effective measurement method.

Numerical Investigation Of Supersonic Flow Over A Wedge By Solving 2d Euler Equations Utilizing The Steger–Warming Flux Vector Splitting (Fvs) Scheme, Mitch Wolff, Hashim H. Abada, Hussein Awad Kurdi Awad Kurdi Saad

Mechanical and Materials Engineering Faculty Publications

Supersonic flow over a half-angle wedge (θ = 15°) with an upstream Mach number of 2.0 was investigated using 2D Euler equations where sea level conditions were considered. The investigation employed the Steger–Warming flux vector splitting (FVS) method executed in MATLAB 9.13.0 (R2022b) software. The study involved a meticulous comparison between theoretical calculations and numerical results. Particularly, the research emphasized the angle of oblique shock and downstream flow properties. A substantial iteration count of 2000 iteratively refined the outcomes, underscoring the role of advanced computational resources. Validation and comparative assessment were conducted to elucidate the superiority of the Steger–Warming flux …