Digital Commons Network^™

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 …

Wet Gas Metering Performance Using Conventional Flow Measurement Devices, Vitali Mwinyi

Tanzania Journal of Engineering and Technology (TJET)

The demand for and production of natural wet gas from wells has significantly risen in recent years. Although natural gas liquids hold substantial value in the oil and gas market, their presence in wet gas adversely affects gas metering, leading to overreading during measurement. A comprehensive study has been undertaken to formulate and enhance correlations for rectifying overreading in wet gas metering. Nevertheless, most current correlations are designed for horizontal configurations of traditional meters. Mitigating this constraint is crucial to consider the impact of gravity on pressure loss in vertically oriented systems. This study seeks to evaluate the efficacy of …

Fuzzy-Ahp Based Decision Support System For The Selection Of Optimal Maintenance Strategy For Meter Gauge Railway Infrastructure: A Review, Hamisi J. Maulid

Tanzania Journal of Engineering and Technology (TJET)

There are many uncertainties and complexities associated with maintaining Meter Gauge Railway (MGR) infrastructure, which calls for a methodical approach to decision-making. The development and application of a fuzzy-AHP-based decision support system (DSS) to select the optimal maintenance strategy for the MGR are presented in this study. The review covers research from 2013 to 2023 and focusses on the use of Multi-Criteria Decision Making (MCDM) and Fuzzy Analytic Hierarchy Process (Fuzzy-AHP) techniques in railway infrastructure maintenance. To manage the inherent uncertainties and subjective judgements involved in maintenance decision-making, the Fuzzy-AHP methodology combines fuzzy logic with the Analytic Hierarchy Process (AHP). …

Analysis Of An Improved Reliability Dual-Buck Structured Three-Level Flying Capacitor Inverter, Almachius Kahwa Dr.

Tanzania Journal of Engineering and Technology (TJET)

With the increased demand for high-reliability power converters in the electric drive-train and propulsion systems, the efforts to design and analyze converters with high fault tolerance have become apparent. Among the emerging trends to improve the reliability of power converters is the incorporation of dual-buck (DB) structures in traditional converter topologies. Thus, this paper studies a single-phase dual-buck structured three-level flying capacitor (FC) inverter. The dual-buck flying capacitor (DBFC) inverter was constructed in such a way as to suppress the shoot-through problems that may occur because of the switching mismatch and gate driver delay, as exhibited in the traditional FC …

Review On Gas-To-Liquids Conversion Technology: Lessons From Case Studies And Potential Strategies For Implementation In Tanzania, Joseph H. Kihedu

Tanzania Journal of Engineering and Technology (TJET)

This review paper explores the transformative potential of Gas-to- Liquids (GTL) technology for harnessing Tanzania's vast natural gas resources. With significant discoveries of natural gas reserves totalling up to 57 Tcf in fields such as Songosongo, Mnazi Bay, Block 1, 2, 3 and 4. Tanzania is positioned to leverage GTL technology to convert these resources into high-value liquid fuels like gasoline, diesel and naphtha. Review of GTL process, its products and applications has been done. By analysing successful GTL projects globally and drawing lessons applicable to Tanzania, this paper provides strategic recommendations for policymakers and stakeholders to foster GTL development. …

A Review Of Lithium-Ion Battery Capacity Fade Deceleration At Power Fluctuations In Renewable Energy Systems, Isaac Gwayi

Tanzania Journal of Engineering and Technology (TJET)

Application of lithium-ion (Li-ion) batteries to store energy in renewable energy systems (RESs) is increasing due to their promising properties. Therefore, it is crucial to understand aging behaviours of Li-ion battery during RES life time as this directly affects cost of energy. Li-ion battery aging can be categorised into calendar aging and cycle aging. Calendar aging depends mainly on temperature and state of charge (SoC). In addition to temperature and SoC, cycle aging depends also on charge and discharge current rates and cut-off voltages. Higher current rates lead to faster Li-ion battery aging. It is necessary to identify appropriate battery …

Assessment Of Maintenance Performance Level Of Selected Hydropower Plants In Tanzania, Mahamudu H. Mtebwa

Tanzania Journal of Engineering and Technology (TJET)

Despite significant progress in increasing electricity access to over 78%, electricity reliability in Tanzania remains a concern, with frequent power outages reported. Maintenance issues in hydropower plants have been identified as a critical factor contributing to this problem. However, the specific maintenance performance levels have not been fully assessed. This study conducts a comprehensive evaluation of the maintenance performance of four key hydropower plants: Kidatu (204 MW), Kihansi (180 MW), Mtera (80 MW), and New Pangani Falls (68 MW). Data collected from staff surveys and maintenance records between 2018 and 2022 were used in the study. Although staff demonstrated a …

Design And Control Of A Versatile Modular Soft Robotic System With Integrated Resource Sharing And Self-Reconfiguration Capabilities, Joshua Knospler

Theses and Dissertations

Modular, self‑reconfigurable soft robots promise unprecedented versatility by combining the compliance of soft materials with the adaptability of modular architectures. This thesis presents an integrated system of pneumatic, bending-type soft actuator modules. Modules are compact and fully equipped with tunable magnetic and electromechanical connections for low‑power attachment and detachment and a novel power-air-communication (PAC) connector for seamless sharing of electricity, compressed air, and digital signals. This work examines two representative assemblies: ManusBot, a pinching gripper, and TendrilBot, a versatile linear configuration for various tasks. Their grasping performance, variable stiffness, and radial support capabilities are characterized. A magnetic interlock and an …

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 …

Predicting The Influence Of Aggregate Size And Distribution On Cementitious Concrete Properties: A Review, Innocent J. Macha

Tanzania Journal of Engineering and Technology (TJET)

Cement concrete has been in use for centuries as one of the primary construction materials. Its demand in the construction industry is expected to continue for several centuries before the full development of alternative products. However, one of the main areas of research interest is understanding how its constituents can be tailored to make its properties predictable to reduce risks associated with structural failures, reconstruction and reduced durability. These hindrances associated with cementitious concrete result from several attributes, including constituent material characteristics, mixing ratios and workmanship. Understanding the predictability of cement concrete properties requires computer modelling tools to provide reliable …

Root Cause Analysis Of Performance Degradation For An Xyz Thermal Power Plant In Tanzania, Simon I. Marandu

Tanzania Journal of Engineering and Technology (TJET)

Thermal power plants in Tanzania have been experiencing performance degradation, typically arising from component and subsystem failures, which contribute to power system instability and unreliability. This paper presents a case study of the root causes of performance degradation of an XYZ thermal power plant. The study was conducted by reviewing plant documentations, including maintenance and operational data logbooks, and by standardising the approach through the adoption of ISO 14224:2016 for maintenance and reliability data exchange. Data evaluation was carried out using principal component analysis and scree plot analytical techniques to enhance the depth and accuracy of root cause identification. Additionally, …

A Yolo-Based Deep Learning Approach For Vibration-Based Rotating Shaft Imbalance Detection, Abdelhameed Zayed Dr., Ali Siam Dr.

Journal of Engineering Research

One of the prevailing causes of vibrations in machines is rotor imbalance. Rotor balancing can be used to fix the majority of rotating machinery issues. When it comes to high-speed running equipment, even a slight imbalance can lead to serious issues and decrease the operational efficiency of rotating machinery. This work proposed a deep learning approach for the detection of binary and multiclass imbalance in rotating shafts. A YOLOv11 model-based approach is developed to detect imbalance and identify unbalanced rotor positions. To precisely identify unbalanced positions, this method trains the YOLOv11 model using numerous sets of measured response data and …

Cyclic Combustion Pressure Dynamics Of A Diesel Engine Operating On Waste Frying Oil Biodiesel Blends Using Wavelets, Shady Elmozy, Ahmed Khaira Dr., Elshenawy Elshenawy Prof. Dr., Ali Mohamed Dr., Medhat Elkelawy Prof. Dr,

Journal of Engineering Research

This paper investigates the cyclic combustion pressure dynamics of a single-cylinder diesel engine burning waste frying oil biodiesel blends, employing statistical analysis and continuous wavelet transform (CWT) to evaluate combustion stability. Experiments were conducted at a constant engine load (90%) and speed (1500 rpm), with in-cylinder pressure data collected over 400 consecutive cycles for conventional diesel (RD) and biodiesel blends (UB10, UB30, UB50). Results demonstrate that biodiesel blends marginally reduce average peak cylinder pressure (PP) by 0.3–3.8% while lowering PP variability, evidenced by declining coefficients of variation (COV-PP: 1.27–1.48%), attributed to biodiesel’s elevated viscosity promoting consistent fuel-air mixing. Conversely, mean …

An Eulerian-Pfem Approach To Model Transient Capillary Forces On Moving Contact Lines Of Spreading Liquid Drops: Applications In Hydraulic And Fluid Dynamics, Elaf N. Mahrous, Syed Yousufuddin, Muhammad Saleem Professor, Mohammed N. Iqbal, Muhammad T. Bin-Saleem

Journal of Engineering Research

This study addresses the complexities of simulating multiphase flows, particularly the dynamics of droplet behaviour on solid substrates, which are influenced by intricate capillary interactions. Despite advancements in fixed-grid and moving-grid methodologies, there remains a critical gap in accurately modelling transient phenomena and dissipative forces at the solid-liquid interface. We introduce a novel Eulerian-particle finite element method (PFEM) framework that captures the transient capillary forces associated with the movement of contact lines in liquid droplet spreading scenarios. Through a numerical assessment of three established dissipative force models—Jiang’s, Bracke’s, and Seeberg’s we identify Jiang's model as the most effective and stable …

Corrosion Mitigation And Monitoring Of Bridge Tendons And Failure Forecasting Of Wastewater Force Mains, Stanley Chike Agbakansi

USF Tampa Graduate Theses and Dissertations

Corrosion remains a significant threat to civil infrastructure, resulting in costly repairsand potential structural failures. This dissertation addresses three critical aspects of corrosion: mitigation and monitoring of post-tensioned bridge tendons, and failure forecasting of wastewater force mains due to internal corrosion.

First, the research investigates the effectiveness of corrosion inhibitors (CIs) applied via pressure injection (impregnation) in post-tensioned tendons. The protective mechanisms and long-term performance of various inhibitors were evaluated to identify the most effective formulations. Among the tested inhibitors, MCI-2020 — a water-based, migratory, mixed-type corrosion inhibitor — demonstrated the most promising results, showing excellent corrosion protection while preserving …

Empowering Engineering Students To Become More Effective And Self-Regulated Learners Through Course-Integrated Learning Strategies Intervention: A Pilot Study In A Solid Mechanics Course, Huihui Qi, Richard Eugene Vallejo Jr., Changkai Chen, Minju Kim, Alex M. Phan, Marko Lubarda, Celeste Pilegard, Curt Schurgers

Psychology Faculty Articles and Research

Learning is a lifelong process exercised within and beyond the classroom and a vital skill in almost all technical professions. Engineers, in particular, are impacted by rapidly evolving technologies and practices that require continuous learning and adaptation long after their training and the initial transition into their professional careers. However, despite the critical role of learning in their academic success and profession, engineering students experience academically rigorous and challenging courses with very little emphasis or conscious focus on learning strategies that power effective learning. Often-used learning strategies such as rereading, highlighting, repetition, and memorization are intuitive for many students, yet …

Nanoscale Structure-Property Relationships Of Cyanate Ester As A Function Of Extent Of Cure, Khatereh Kashmari, Josh Kemppainen, Sagar U. Patil, Julieta Barroeta Robles, Pascal Hubert, Gregory Odegard

Michigan Tech Publications

Cyanate esters are key thermosetting resins for composite materials that require structural integrity and resistance to elevated temperatures. Because cyanate ester composites require relatively high processing temperatures, they are susceptible to the formation of process-induced residual stresses, which compromise their overall strength and durability. Process modeling is a key strategy for optimizing processing parameters to minimize such residual stresses. A necessary component of effective and efficient process modeling of composites is computationally established resin property evolution relationships for a range of processing parameters. In this study, the physical, mechanical, and thermal properties of a cyanate ester resin are established as …

How’S It Growing? Tools For Observing Snow And Sea Ice In A Changing Arctic Ocean, Ian Alexander Raphael

Dartmouth College Ph.D Dissertations

September Arctic sea ice extent has diminished by roughly 50% in the 45 years since satellite observations began. The Arctic Ocean may experience ice-free summers within the next decade, with implications for habitat, resource extraction, geopolitics, and local and global climate change. To predict how Arctic sea ice will change in the future, we need to understand its behavior in the present. In situ sea ice mass balance measurements (snow accumulation, ice growth, snow and ice surface melt, and bottom melt) are essential for studying the processes driving rapid changes in the ice pack, and for validating remote sensing measurements …

Development Of An Embedded Iot Board For Real-Time Floor Estimation Of Autonomous Robots, Carter J. Sorensen

Electronic Theses and Dissertations

As service robots become more prevalent in multi-story environments such as hospitals, hotels, and laboratories, accurate floor-level detection is critical to ensuring operational reliability. Consider a robot tasked with delivering medical samples in a multi-story laboratory. Without accurate feedback, a robot exiting on the wrong floor could introduce delays, disrupt workflows, or compromise sample integrity. Internet of Things (IoT) technologies offer a way to address these risks by providing real-time error detection and corrective capability. However, current IoT-based floor estimation systems often require invasive modifications to building infrastructure—particularly elevator control panels. These approaches introduce challenges related to cost, liability, backward …

Human Gut Commensal Alistipes Timonensis Modulates The Host Lipidome And Delivers Anti-Inflammatory Outer Membrane Vesicles To Suppress Colitis In An Il10-Deficient Mouse Model, Ethan Older, Mary K. Mitchell, Andrew Campbell, Xiaoying Lian, Michael Madden, Yuzhen Wang, Lauren E. Van De Wal, Thelma Zaw, Brandon N. Vanderveen, Rodney Tatum, E. Angela Murphy, Yan-Hua Chen, Daping Fang, Melissa Ellermann, Jie Li

Faculty Publications

Correlative studies have linked human gut microbes to specific health conditions. Alistipes is one such microbial genus negatively linked to inflammatory bowel disease (IBD). However, the protective role of Alistipes in IBD is understudied, and the underlying molecular mechanisms remain unknown. In this study, colonization of Il10-deficient mice with Alistipes timonensis DSM 27924 delays colitis development. Colonization does not significantly alter the gut microbiome composition, but instead shifts the host plasma lipidome, increasing phosphatidic acids while decreasing triglycerides. Outer membrane vesicles (OMVs) derived from Alistipes are detected in the plasma of colonized mice, carrying potentially immunomodulatory metabolites into the …

Bloom Pattern Data, Zhongyuan Wang, Robert J. Lang, Larry L. Howell

ScholarsArchive Data

This data is the supplementary material of the paper "Bloom Patterns: Radially Expansive, Developable, and Flat-Foldable Origami" by Zhongyuan (Kelvin) Wang , Robert J. Lang, and Larry L. Howell.

We present bloom patterns as a family of radially expansive, flat-foldable, and developable origami patterns, many of which are rotationally symmetric. Bloom patterns are defined with a generalized definition and a standardized definition. A classification scheme for bloom patterns is identified, and several types of bloom patterns are analysed. The distinct helical nature that characterizes bloom patterns is described, and a set of compatibility conditions is derived to help determine if …

Derivation And Experimental Validation Of A Parameterized Nonlinear Froude–Krylov Force Model For Heaving-Point-Absorber Wave Energy Converters, Houssein Yassin, Tania Demonte Gonzalez, Gordon Parker, Giorgio Bacelli, Carlos Michelen

Michigan Tech Publications

Wave energy converters (WECs) have gained significant attention as a promising renewable energy source. Optimal control strategies, crucial for maximizing energy extraction, have traditionally relied on linear models based on small motion assumptions. However, recent studies indicate that these models do not adequately capture the complex dynamics of WECs, especially when large motions are introduced to enhance power absorption. The nonlinear Froude–Krylov (FK) forces, particularly in heaving-point-absorbers with varying cross-sectional areas, are acknowledged as key contributors to this discrepancy. While high-fidelity computational models are accurate, they are impractical for real-time control applications due to their complexity. This paper presents a …

2-Axis Solar Panel Tracker, Danica Wong, Oliver Barnaal, Anton Orme

Mechanical Engineering

Solar panels generate energy from sunlight. To do this it’s important that they remain pointed at the sun throughout the day. The Cal Poly Micro Grid Lab runs a class that uses a student made solar panel and tracking mount as an instructional tool. This project is beginning to show signs of wear from outdoor use and is unable to run without constant input due to some significant design flaws. The lab needs a new version of the mount to be made that is significantly more reliable and easier to use.

In-Situ Defect Detection In Selective Laser Melting Using Convolutional Neural Networks, Ethan Gaigalas

Master's Theses

This thesis develops and trains a convolutional neural network (CNN) to classify defects in metal parts produced by selective laser melting (SLM) using acoustic emission (AE) data. The model successfully identified porosity and standard build layers with high accuracy but consistently struggled to classify lack of fusion (LOF) defects, regardless of input type, normalization, or class count. These results suggest that while AE signals contain distinguishable features for certain defect types, LOF signals may be too subtle or inconsistent for reliable detection. The study addresses the ongoing challenge of in-situ quality monitoring in metal additive manufacturing, where defects like cracks, …

Scitechatorium, Olivia Lafferty, Yvonne Brien Miller, Colton Swinth, Savannah Pinheiro, Gage Heinze

Mechanical Engineering

Bellevue Santa-Fe Charter School (Bellevue) is a K6th grade public charter elementary school in Avila Beach, California. The primary focus at Bellevue is fostering unique learning experiences, empowering students through project-based learning, and engaging students in creative endeavors. Following these themes, the school has allocated space and funding for an on-campus science and technology museum known as the SciTechatorium. The museum is currently open during students’ lunch period, providing interactive displays on concepts in human biology, nature and wildlife, physics, and electronics. Bellevue’s K-6th grade science teacher, Christian Strauli, and Bellevue parent volunteers are primarily responsible for the museum’s upkeep …

Drone Package Delivery System, Aiden Tyler Sim, Ryan Anders O'Toole, Matthew Karl Wyant, James Shaw Glanville

Mechanical Engineering

In response to the demands of the 2025 C-UASC (California Unmanned Aerial Systems Competition), our team developed an autonomous drone payload delivery system capable of two distinct delivery modes: a precision-controlled descent and a high-speed aerial drop. Designed for modular integration with UAV platforms, the system prioritizes reliability, accuracy, and simplicity under desert environmental conditions. Our solution features a custom winch mechanism with a programmable stepper motor, a passive mechanical hook for tension-based release, and a servo-actuated trapdoor for high-altitude drops. The design was extensively tested for structural integrity, motor torque requirements, drop precision, and electronics reliability—culminating in a robust …

Torsional Vibration Kit Simulator (Tks), Joseph Thachet, Luca Lawson, Ryan Ota, Otis Mcloughlin

Mechanical Engineering

The goal of this project was to create torsional vibration on a shaft while limiting axial and radial vibration. To do this an eddy current brake was used to slow down a rotating shaft. The electromagnets used to create the eddy currents are able to be turned on and off at a frequency produced by a function generator. This power cycling of the electromagnets creates an alternating braking force thereby inducing torsional vibration while limiting the other two vibration types

Mae Enewsbrief Jan-Mar 2025, Department Of Mechanical And Aerospace Engineering, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Mae Enewsbrief Oct-Dec 2024, Department Of Mechanical And Aerospace Engineering, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Nsf Eec: Establishing Utrgv’S Center For Broadening Participation In Engineering: Engage, Educate, Enrich, Ala Qubbaj, Laura Benitez, Noe Vargas Hernandez, Constantine Tarawneh, Arturo A. Fuentes, Nazmul Islam, Edna Orozco-Leonhardt, Thuy Vu, Angela M. Chapman

Mechanical Engineering Faculty Publications

Hispanics are one of the fastest growing populations in the US, yet they are underrepresented in engineering. University of Texas Rio Grande Valley (UTRGV), a major Hispanic Serving Institution (HSI) with a student population over 95% Hispanic, is well-positioned to address this disparity. UTRGV established a Center for Broadening Participation in Engineering: Engage, Educate, Enrich (CBPE-E3) to enhance Hispanic participation in engineering from early awareness through professional employment. The CBPE -E3 aims to increase enrollment, retention, and advancement rates of Hispanic students in higher education engineering, especially Latinas facing intersectional barriers of race and gender. The CBPE -E3 envisions becoming …