Digital Commons Network^™

Distinct Co2 Electroreduction Behaviors Over Planar And Non-Planar Cobalt Molecular Catalysts, Ru Jia, Cheng-Biao Zhu, Zi-Mo Zhang, Tuo Wang, Kai-Cong Yang, Guang-Zhe Wang, Yang Hu, Ting-Ting Zhang, Zhen-Wei Wei, Li Xiao, Gong-Wei Wang, Lin Zhuang

Journal of Electrochemistry

Molecular catalysts serve as ideal platforms for studying electrocatalytic reaction mechanisms. While current research mainly focuses on modulating central metals or surrounding ligands, the influence of molecular spatial configuration remains largely unexplored. Herein, we synthesized two cobalt complexes with similar ligand environments but distinct spatial geometries, a planar cobalt hexaazamacrocyclic complex (CoHAM) and a non-planar acyclic Co(phen)₂Cl₂, and evaluated their performance in CO₂ reduction reaction (CO₂RR). The planar CoHAM exhibited dramatically superior CO₂RR performance compared to the non-planar Co(phen)₂Cl₂. Through a series of combined analyses using in-situ …

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 …

Compact Low-Profile Dual-Band Microstrip-Fed Monopole Antenna For Wlan And Lte Applications, Hashimu U. Iddi

Tanzania Journal of Engineering and Technology (TJET)

The rapid advancement in wireless communication technologies has led to rising user demand for high-speed data transfer, seamless connectivity, and improved wireless communication efficiency. Therefore, it is inevitable to develop efficient and compact antennas which can support different frequency bands of various wireless system standards in mobile devices. A compact, low-profile microstrip-fed monopole antenna operating in dual bands, 2.45 GHz and 5.8 GHz, and suitable for WLAN and LTE applications is proposed in this study. The proposed antenna’s radiating element was carefully designed using slotting techniques and optimising the various parameters for achieving the required resonance frequency. The proposed compact, …

Trajectory-Based Model Predictive Control For Rotary Crane Sway Suppression With Only Horizontal Boom Actuation, Haryson J. Nyobuya

Tanzania Journal of Engineering and Technology (TJET)

Safety is of biggest importance in construction and industrial activities involving rotary cranes. These cranes are huge and responsible of moving large parts or/and materials from different positions. Now operating these cranes tend to be subdue to pay load oscillations when moving the load for which is extremely dangerous when not suppressed. This study proposes the generation of trajectory using Model predictive control approach with reduced control horizon compared to state horizon. Reduced control horizon design reduces computational time for trajectory generation while maintaining the pay-load sways to a minimum. In this approach the complex dynamic model is reduced to …

On The Use Of Lorawan For Smart Fishing Applications In The Blue Economy Sector, Eva Shayo

Tanzania Journal of Engineering and Technology (TJET)

The growth of digital technology is expected to transform small-scale fishery sectors, where a need for robust, low-cost, long-range communication networks becomes critical. There exist several technologies that are used in the fishery sector but they are never affordable to small scale fisheries. This study evaluates the feasibility of using low cost Long Range Wide Area Network (LoRaWAN) technology specifically tailored for smart fishing environments to small scale fishery sector. Using simulation, we assess the performance of the key performance metrics including probability of success and energy efficiency under varying device densities and time. During evaluation, we considered end devices …

Optimal Design And Techno-Economic And Environmental Analysis Of A Hybrid Solar Pv-Battery-Generator System For Off-Grid Telecom Towers And Rural Households: Case Of Misughaa Village In Tanzania, Ibrahim Mwammenywa, Martha Mwaikenda

Tanzania Journal of Engineering and Technology (TJET)

Telecommunication services are pivotal for the socio-economic development of communities, regions, and countries. Extensive and reliable telecom infrastructure enables populations to leverage development opportunities and bridge the urban-rural divide. However, extending these services to rural areas often necessitates the deployment of telecommunication towers in locations lacking national grid access. Consequently, service providers typically rely on diesel generators (DG) for power, which introduces significant challenges. These challenges include a high operational expenditure (OPEX), rendering telecom services unaffordable for rural communities, and substantial environmental pollution from greenhouse gas (GHG) emissions. This study aims to present an optimal design, encompassing sizing and economic …

Voltage Profile Enhancement In Iliceto Shield Wire Scheme For Rural Electrification: Case Study Of Chalinze-Mbwewe Transmission Line In Tanzania, Ebeneza Chaula, Ibrahim Mwammenywa, Santos Kihwele

Tanzania Journal of Engineering and Technology (TJET)

Rural electrification faces challenges due to significant voltage drops over long transmission distances, affecting reliability and power quality. While the Iliceto Shield Wire Scheme (ISWS) offers a modern cost-effective solution, voltage stability remains a challenge. This study analyses voltage profile enhancement within ISWS, focusing on the Chalinze-Mbwewe section of the 132 kV transmission line, using LTSpice simulations. Due to LTSpice limitations, direct solar PV integration was mimicked by introducing a secondary voltage source at each load centre, producing 33 kV to match the original source voltage. This approach maintained improved voltage profile from Msoga Village to Mbwewe over 80.9 Kilometers. …

The Impact Of Gender Sensitization On Requirements Elicitation: A Controlled Experiment, Ruthbertha Kateule, Salome Maro, Leonard Peter Binamungu

Tanzania Journal of Engineering and Technology (TJET)

Previous studies in software engineering have reported the importance of considering gender aspects in various software engineering activities, including requirements engineering, however, to the best of our knowledge, no work has investigated the impact of gender sensitisation on eliciting gender inclusive software requirements. The objective of this study was to understand the impact of gender sensitisation on software requirements elicitation. We conducted a controlled experiment using 40 undergraduate students from three different computing programs at the University of Dar es Salaam. The 40 participants were divided into 9 groups with both males and females. The participants were asked to elicit …

Enhancing Community Engagement Through ‘Nitunze Kilombero’ Mobile App: Case Of Climate Land Use And Cover Management For Kilombero Basin, Ghanima Chanzi, Subira Munishi

Tanzania Journal of Engineering and Technology (TJET)

The Kilombero Basin in southeastern Tanzania faces significant challenges due to rapid land use and land cover (LULC) changes driven by climate change, population growth, and unsustainable farming practices. This study assessed the role of community engagement and digital reporting through the 'NITUNZE KILOMBERO', mobile application in supporting water resources management in the basin. The App facilitates real-time reporting of environmental issues, provides educational resources, and enables collaboration between local communities and authorities. A mixed-methods approach, including household surveys and key informant interviews, was employed to assess the app's effectiveness. Results indicate high community awareness of LULC impacts, with 85% …

Load Flow And Fault Performance Evaluation Of Interconnected Minigrids In Uganda Using Digsilent Powerfactory, Prossy Mutesi, Santos Kihwele, Emmanuel Matee

Tanzania Journal of Engineering and Technology (TJET)

The increasing demand for decentralized, reliable electricity in rural Sub-Saharan Africa has catalyzed the deployment of minigrids as an intermediate electrification strategy. This study investigates two solar photovoltaic (PV) mini-grids: Kyamugarura and Kanyegaramire, located in western Uganda, approximately 3km apart. Each mini grid initially consisted of 13 kW installed photovoltaic (PV) capacity, supplying power to households and small businesses. Due to rising demand and regular evening blackouts, both mini-grids are being upgraded to 57 kWp each. The integration of these upgraded systems into the national utility grid is proposed and simulated to evaluate performance improvements under two medium-voltage interconnection options: …

Efficient, Secure Learning And Resource Management For Wireless Networks, Jiahao Xue

USF Tampa Graduate Theses and Dissertations

The rapid advancement of wireless networks has enabled a wide range of applications such as federated learning (FL) and Internet of Things, with supporting technologies like radio frequency identification (RFID). However, resource management and security challenges in wireless networks remain insufficiently addressed for these representative applications. In this dissertation, we first investigate wireless resource management for FL, then study novel attack and defense mechanisms for RFID systems. Finally, we analyze the performance and security of artificial intelligence (AI)-enabled next generation wireless networks.

First, we investigate the client assignment and bandwidth allocation problem for FL in a multi-provider wireless setting. Unlike …

Modeling And Optimization Of Li-Ion Battery Recycling Process, Wang Lingling, Zhou Panpan, Ma Yulong

Dianchi(Changsha)

No abstract provided.

Review On Capacity Degradation Mechanisms And Lifetime Prediction Of Energy Storage Li-Ion Battery, Ma Yue, Chen Yanqiao, Wang Chu, Wang Xianwen, Liu Hui, Chen Yifei, Chen Lai, Yan Kang, Su Yuefeng

Dianchi(Changsha)

No abstract provided.

Opportunities And Challenges Of Cross-Border E-Commerce In Li-Ion Batteries, Ma Jingjing, Chen Xianyi

Dianchi(Changsha)

No abstract provided.

Ion Irradiation Of Microelectromechanical Resonators, Hengky Chandrahalim, David D. Lynes

AFIT Patents

A method of enhancing an electromechanical coupling coefficient of a microelectromechanical (“MEMS”) device. The method includes applying, to a fully fabricated MEMS device, heavy particle ion radiation to the MEMS device at a fluence of at least 1×10¹⁴ cm.⁻². According to other embodiments of the present invention are directed to a bandpass filter comprising a plurality of MEMS devices fabricated in accordance with the methods provided. The MEMS of the plurality are electronically or mechanically coupled.

A Storm-Ai Primer With An Operationally Representative Example, Shiu-Kai Chin, Matthew Clark, Garrett Katz, Jae C. Oh, William Young

Electrical Engineering and Computer Science - All Scholarship

A STORM-AI Primer with an Operationally Representative Example presents the Systems-Theoretic Technical and Operational Risk Management with Artificial Intelligence (STORM-AI) methodology, a transdisciplinary framework for establishing the trustworthiness of mission systems that may incorporate AI components. The core value proposition of STORM-AI is mission assurance—ensuring that mission systems behave with the predictability and proportionality required by senior leadership and demanded by international humanitarian law. STORM-AI achieves this by faithfully preserving commander's intent from high-level mission descriptions down to hardware-level behavioral specifications through a structured sequence of four formally grounded models: a Mission Model, a Protection (Loss Control) Model, a Security …

An Access-Control Logic In Hol (Trindemossen 2), Shiu-Kai Chin

Electrical Engineering and Computer Science - All Scholarship

This manual documents the embedding of an access-control logic (ACL) — as presented in the textbook Access Control, Security, and Trust: A Logical Approach (Chin and Older, 2011) — within the Cambridge Higher-Order Logic theorem prover HOL-4. The logic is a multi-agent modal logic with Kripke semantics. Its purpose is to reason about authentication, authorization, integrity, security, and trust. The inference rules of the ACL are proved to be sound. The inference rules are a command-and-control (C2) calculus. The value of the ACL is its support for rigorous, verified, and trustworthy policies for complete mediation, i.e., where all actions are …

Decarbonizing Electrical Substations: An Integrative Review Of Green Technologies And Sustainable Practices Across The Infrastructure Life Cycle, Sulthan Syah Ali, Mohammed Ali Berawi, Mustika Sari

Smart City

Decarbonization of electrical infrastructure s becoming increasingly important in efforts to meet climate change mitigation targets, particularly in reducing emissions from substations. However, conventional substations continue to release significant quantities of GHG emissions throughout their life cycle As an example, a typical 500 kV substation emits around 150,000 tCO2e from construction to decommissioning. In addition, the development of green substation concepts remains limited, particularly in Indonesia where standardized approaches are not yet established. In response to the need for more sustainable power infrastructure, this study aims to identify, classify, and review all types of green technologies, practices, and innovations that …

Adaptive Intervention Strategies In Co-Evolving Multiplex Networks: A Reinforcement Learning Approach To Real-Time Misinformation Containment, Anjali Ashokrao Bhadre Dr., Harshvardhan Prabhakar Ghongade Dr.

Northeast Journal of Complex Systems (NEJCS)

The growing transmission of misinformation via social media creates serious challenges to public health, democracy and social cohesion. To date, methods used to contain misinformation rely upon static representations of networks and set rules for interventions. In contrast, this study presents the first Multiplex Adaptive Reinforcement Intervention Network (MARIN), a framework for real-time adaptive intervention in the context of dynamic misinformation transmission using co-evolving multiplex networks and deep reinforcement learning. Unlike past studies that have assumed static network structures, MARIN has the ability to allow for dynamic changes in network topology as a result of both misinformation transmission and intervention …

Techno-Economic And Environmental Analysis Of Wind-Powered Green Hydrogen Production In Nigeria, Ignatius Kema Okakwu, Ayodeji Akinsoji Okubanjo, Samson Oladayo Ayanlade, Akintunde Samson Alayande, Solomon Olanrewaju Giwa, Abraham Olatide Amole, Etinosa Noma-Osaghe, Ajibola Oluwafemi Oyedeji

Al-Bahir

Green hydrogen is becoming a viable option for clean energy, and the need to reduce greenhouse gas emissions has also become a popular sustainable energy source. In this paper, we evaluate the technoeconomic and environmental feasibility of green hydrogen production from wind energy in five Nigerian cities: Kano, Jos, Maiduguri, Ikeja, and Ikorodu. Energy potential from wind energy is estimated by using the Weibull distribution method, and six wind turbines are used to calculate electricity generation and hydrogen production. Economics of wind power are estimated through levelized cost of energy (LCOE), levelized cost of hydrogen (LCOH), payback period (PBP), and …

Load Profile Analysis And Forecasting For Rural Mini Grids In Uganda, Prossy Mutesi, Santos L. Kihwele, Emmanuel S. Matee

Tanzania Journal of Science

Accurate load forecasting is essential for the reliable and cost-effective operation of rural mini grids, where constrained generation capacity and high penetration of renewable energy resources require well-informed operational decisions. This study examines electricity demand characteristics and forecasting performance for the Buzaami and Ssenyondo mini grids in Uganda, with particular focus on diurnal load profiles, peak demand behavior, and seasonal variability. 2022 operational data show extended peak demand from early morning to late evening, driven by socio-economic activities that strain resource scheduling and reliability management. To address these challenges, the study evaluates and compares Long Short-Term Memory (LSTM) networks, fuzzy …

Modelling And Analysis Of 50 Mwp Solar Pv Integration Into Tanzania’S Transmission Network: A Case Study Of Tagamenda Substation, Iringa Region, Santos Kihwele

Tanzania Journal of Science

While increasing the share of renewable energy in the grid, grid integration studies for the utility solar photovoltaic (PV) plants are vital, given their intermittency and the fact that Tanzania has never had one connected to the grid. This paper presents a 50 MWp grid integration study, including a technical analysis conducted using PSS®E software. The study investigates the grid behaviour during the integration of the 50 MWp solar plant, considering the most suitable technical and economic solutions. The study analysed the load flow under normal conditions, contingency analysis (N-1), short- circuit analysis, and voltage stability assessment. The results show …

Robust Real-Time Uav Target Tracking With Onboard Vision-Based Yaw Control, Rylan Malarchick, Jose Castelblanco, Enrique Amaya, Carmen Dimario, Graysen Brinkman, Chirag Kumar, Kiwon Yoon, Sajid Berhane

Beyond: Undergraduate Research Journal

Autonomous tracking of agile unmanned aerial vehicles (UAVs) presents significant challenges for real-time perception and control systems. This work presents AIRHOUND (Autonomous Intelligent Rotorcraft for Hostile Object Unified Navigation and Detection), a UAV platform implementing vision-based yaw tracking through a modular ROS2 software architecture. The system employs YOLOv8 object detection optimized with NVIDIA TensorRT for embedded deployment on an NVIDIA Jetson Orin companion computer. Detected targets are processed through a geometric tracking module that converts pixel coordinates to angular yaw errors using pinhole camera intrinsics, with a proportional controller generating rate-limited yaw commands. These commands are streamed to a PX4 …

The Dynamics Of Educational Change: A Complex Systems Perspective, Preethi Nanjundan, Lijo Thomas, Abith K. Sunil

Northeast Journal of Complex Systems (NEJCS)

The perception of university teachers toward educational reforms plays an important role in determining the success of changes introduced in the education sector. This study focuses on teachers’ attitudes toward change, their emotional responses, and their overall views on educational reforms. Across the world, many educational reforms have failed to achieve their expected outcomes in improving teaching practices and student learning. As education systems are highly complex, the approach toward implementing reforms has also changed over time. Some reforms are introduced gradually, while others involve major innovations within the system. Complexity theory provides useful insights and tools that help educators …

Literature Landscape Of Government, Academic, And Industry Efforts In Responsible, Secure, And Trustworthy Ai, Jae C. Oh, Shiu-Kai Chin, Garrett Katz, William E. Young, Matt Clark

Electrical Engineering and Computer Science - All Scholarship

This report presents a systematic analysis of 54,628 AI research papers published between 2021 and 2025, examining the extent to which current government, academic, and industry efforts address the trustworthiness requirements of mission-critical AI systems. Papers were classified along two dimensions: organizational tier (from AI model to mission/business pro- cess) using NIST SP 800-39, and systems engineering lifecycle phase using ISO/IEC/IEEE 15288. Classification combined automated LLM-assisted screening with human validation, achieving inter-rater reliability measured by Krippendorff’s α and Gwet’s AC1. Only 16.8% of papers examined addressed any aspect of AI trustworthiness, reliability, or security, and virtually all were concentrated at …

An Instance Segmentation Based Global Mppt Method For Pv Systems Under Partial Shading Condition, Ehab Ur Rahman, Yousef Mahmoud, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

Partial shading in photovoltaic (PV) systems creates multiple Local Maximum Power Points (LMPPs) on the power-voltage (P-V) curve, causing conventional Maximum Power Point Tracking (MPPT) algorithms to converge prematurely to suboptimal operating points and resulting in significant energy losses. This work proposes a novel vision-based framework that integrates computer vision with Global Maximum Power Point Tracking (GMPPT) to maximize energy harvesting in partially shaded PV systems. The proposed method captures real-time imagery of PV panels to identify cell-level shading patterns, which are subsequently mapped to module electrical characteristics to enable direct analytical estimation of the GMPP voltage. An instance segmentation …

Converting Co2 Into Carbon Nanotubes Via Sequential Co2 Methanation And Methane Pyrolysis, Kaiying Wang, Hao Feng, Ahmad Helaley, Xiaoqing He, Bohong Zhang, Jie Huang, Xinhua Liang

Electrical and Computer Engineering Faculty Research & Creative Works

This study presents a sequential thermochemical catalytic process for converting CO₂ into carbon nanotubes (CNTs), achieving nearly 99% overall CO₂ conversion and solid carbon yields of up to 49% in a single pass. The overall transformation is divided into two thermodynamically favorable steps: (1) low-temperature CO₂ methanation to CH₄ over a sol-gel-prepared Ni87Ce_6.5Zr_6.5-SG catalyst, which achieved >95% CO₂ conversion at 250 °C in a single pass, and (2) subsequent methane pyrolysis to CNTs and H₂ over a Ni@Al₂O₃-IE core-shell catalyst, which showed improved stability and carbon …

Energy Efficient Load Balancing In Multi-Band Cellular Networks Via Reinforcement Learning, Ahmed Shoukry El Soukkary

Theses and Dissertations

This thesis investigates energy-efficient load balancing in homogeneous multi-band cellular networks through the joint design of user association (UA) and transmit power allocation (PA). The original mixed-integer nonlinear formulation is decomposed into two coupled yet tractable subproblems: a UA stage and a PA stage for high-frequency bands. For UA, a SINR-ratio-based heuristic is proposed to prioritize users that are most sensitive to suboptimal band assignments, and it is benchmarked against a Max- SINR baseline. For PA, the high-band power control problem is addressed using reinforcement learning, where a Proximal Policy Optimization (PPO) agent learns power levels and band-activation decisions under …

Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed

University Honors Theses

The semiconductor industry's continued growth, driven in large part by demand for artificial intelligence hardware, has highlighted the need for greater workforce development in regions adjacent to major fabrication centers like Oregon's Silicon Forest. This capstone project lays the groundwork for a small scale and student led semiconductor fabrication lab at Portland State University by demonstrating two of the core steps in chip manufacturing: photolithography and thin film deposition. Rather than relying on conventional fixed reticles, this work explores a unique, low cost approach to patterning that uses an ultraviolet-compatible liquid crystal display (LCD) as a programmable reticle, allowing arbitrary …

Universal Communications Module: Converting Ieee2030.5 Xml Files To Ansi/Cta-2045, Wyatt Bilodeaux

University Honors Theses

The goal of this thesis is to discuss the method and organization of the Universal Communication module capstone project. This project was part of the Portland State University Electrical engineering degree program. While this thesis is part of the University honors curriculum. This thesis goes into detail about team structure and how a 9 person engineering capstone project was managed and organized. It looks at how we broke down the project into sections to be able to properly distribute our resources. This was one of the earliest and most important challenges that this capstone team had to tackle. This was …