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Articles 2011 - 2040 of 197969

Full-Text Articles in Engineering

Discrete Fracture Network Application To Rock Slope Stability In An Open Pit Mine, Elvis Karikari Mensah, Erzah Ackah, Reginald Hammah, Hani Mitri Jun 2026

Discrete Fracture Network Application To Rock Slope Stability In An Open Pit Mine, Elvis Karikari Mensah, Erzah Ackah, Reginald Hammah, Hani Mitri

Journal of Sustainable Mining

The stability of rock slopes in open pit mines is crucial for the safety and efficiency of the mining operation. Conventional stability analysis methods, such as kinematic and limit equilibrium analyses, primarily focus on identifying structural failure mechanisms and evaluating their factors of safety. Although insightful, these approaches do not accurately estimate failure volumes and block locations due to their limited consideration of joint frequency and persistence, which are key parameters in understanding block geometries. Discrete fracture network (DFN) modelling addresses these limitations by explicitly simulating rock mass discontinuities in 3D, which automatically incorporates joint spacing and persistence.

This paper …


A Storm-Ai Primer With An Operationally Representative Example, Shiu-Kai Chin, Matthew Clark, Garrett Katz, Jae C. Oh, William Young Jun 2026

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 …


Toward Passwordless Document Encryption, Isaac Henry Teuscher Jun 2026

Toward Passwordless Document Encryption, Isaac Henry Teuscher

Theses and Dissertations

Document files with sensitive information are used across nearly every industry. In recent years, cyberattacks targeting cloud-based file transfer applications have resulted in millions of sensitive documents being exposed. Although document encryption methods exist, they are often limited in usability, security, or deployability. Password-based encryption, the most widely available option, remains vulnerable to brute-force attacks, unauthorized sharing, and human error. We address these gaps in three phases. First, we present a structured comparative framework adapted from the usability-deployability-security model to evaluate nine document encryption methods across 15 design properties, identifying the benefits and limitations of current approaches. Second, we design …


Calibration And Validation Of An Ogden Material Model For Thermoplastic Polyurethane In 3d-Printed Tensegrity Structures, Caleb C. Swain Jun 2026

Calibration And Validation Of An Ogden Material Model For Thermoplastic Polyurethane In 3d-Printed Tensegrity Structures, Caleb C. Swain

Theses and Dissertations

This work is motivated by ongoing efforts within the Smart Materials, Adaptronics, and Shock Laboratory (SMASH Lab) at Brigham Young University (BYU) to develop variable-stiffness, external fixators using 3D-printed tensegrity structures. In the process of designing and evaluating these systems, the need arose to accurately model the nonlinear mechanical behavior of thermoplastic polyurethane (TPU), the primary material used in prototype fabrication. This thesis investigates how accurately a calibrated Ogden material model can predict the nonlinear mechanical response of TPU in 3D-printed tensegrity structures. Experimental data were used to calibrate the parameters of the hyperelastic constitutive model through nonlinear optimization. An …


An Access-Control Logic In Hol (Trindemossen 2), Shiu-Kai Chin Jun 2026

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 …


Upholding Long-Termism In Basic Research To Shape Leading Advantage Of Automotive Industry, Yubo Lian Jun 2026

Upholding Long-Termism In Basic Research To Shape Leading Advantage Of Automotive Industry, Yubo Lian

Bulletin of Chinese Academy of Sciences (Chinese Version)

General Secretary Xi Jinping has pointed out that basic research is the origin of the entire scientific system and the master switch for all technological issues, emphasizing that it must be advanced with greater efforts and more concrete measures. Upholding long-termism in basic research means placing it at the foundation of the innovation chain and maintaining continuous investment with strategic patience characterized by a long-term horizon and high tolerance for failure. Drawing on the author’s industrial practice, this study systematically reviews the characteristics and roles of basic research throughout the development of China’s new energy vehicle industry. In light of …


Engineering 3d Optical Interconnects And Low-Power Radio Frequency Gaze Tracking, Blake P. Crosby Jun 2026

Engineering 3d Optical Interconnects And Low-Power Radio Frequency Gaze Tracking, Blake P. Crosby

Theses and Dissertations

This thesis presents two independent research works in optical in- terconnects and radio-frequency (RF)-based gaze tracking. The first work demonstrates a silicon optical waveguide fabricated from four through-silicon vias (TSVs) produced using two-photon-absorption- assisted photo-electrochemical etching. Unlike conventional TSV fabrica- tion methods, this approach enables highly localized, non-line-of-sight etching in silicon using a focused femtosecond laser. Four approximately 5 μm diameter TSVs were etched through a 200 μm silicon wafer in a 7 μm by 7 μm pattern, leaving a central silicon region that functions as a waveguide. The fabricated structure achieved an aspect ratio of approxi- mately 40:1 with …


Hierarchical Parcel Swapping: A Novel Model In Turbulence, Masoomeh Behrang Jun 2026

Hierarchical Parcel Swapping: A Novel Model In Turbulence, Masoomeh Behrang

Theses and Dissertations

Turbulent mixing plays a central role in a wide range of engineering and natural systems, particularly in reactive flows where turbulence--chemistry interactions strongly influence reaction rates, flame structure, and emissions. Accurately modeling these interactions remains a major challenge due to the multiscale and stochastic nature of turbulence, as well as the nonlinear coupling between transport and chemical kinetics. This dissertation develops and evaluates the Hierarchical Parcel Swapping (HiPS) model, a fully stochastic framework designed to represent turbulence-driven transport and scalar mixing without relying on traditional gradient-based closures. HiPS is investigated both as a standalone turbulence model and as a subgrid …


Rheological Protocol To Assess And Optimize Latex Coagulation Dynamics For The Thin Glove Coagulant Dipping Process, Monday U. Okoronkwo, Kok Kong Ng, Wolfram Franke, Gaurav Sant Jun 2026

Rheological Protocol To Assess And Optimize Latex Coagulation Dynamics For The Thin Glove Coagulant Dipping Process, Monday U. Okoronkwo, Kok Kong Ng, Wolfram Franke, Gaurav Sant

Chemical and Biochemical Engineering Faculty Research & Creative Works

Many products that directly impact the quality of human life today — gloves, catheters, condoms, and baby bottle teats — are made through the latex-dipping technology. While a variety of methods have been developed – e.g., particle counting, turbidimetry, microscopy, and light scattering – which are suitable for studying the coagulation of latex at very low concentrations, much less work has focused on methods suitable for in-situ characterization of latex coagulation in concentrated solutions (e.g., as relevant to the dipping process). This paper presents a process-relevant rheological protocol for assessing and optimizing latex coagulation dynamics for the thin glove coagulant …


Analysis On Thermo-Viscous Steady Fluid Motion Over An Impermeable Infinitely Stretched Horizontal Moving Rectangular Surface, P. Krishna, N. Pothanna, K. Spandana Jun 2026

Analysis On Thermo-Viscous Steady Fluid Motion Over An Impermeable Infinitely Stretched Horizontal Moving Rectangular Surface, P. Krishna, N. Pothanna, K. Spandana

Mansoura Engineering Journal

This study presents analysis on thermo-viscous steady fluid motion over an impermeable infinitely stretched horizontal moving rectangular surface. The numerical results have been found employing R-K method of order 6 shooting techniques developed in Mathematica software ND solve for the flow adaptable equations comprising temperature and velocity. The flow behavior and the impacts of material constraints on the flow region have been analyzed and deliberated taking the help from the generated graphs. The variations of these flow fields have been studied for wide spectrum of physical characteristics which influences the nature of thermo-viscous fluid. The impact of viscosity, constant pressure …


A Conceptual Model Of The External Costs Of Truck Overloading On Road Damage, Emissions, And Traffic Congestion: A Systematic Literature Review, Aleksius Sitepu, Sutanto Soehodho, Andyka Kusuma Jun 2026

A Conceptual Model Of The External Costs Of Truck Overloading On Road Damage, Emissions, And Traffic Congestion: A Systematic Literature Review, Aleksius Sitepu, Sutanto Soehodho, Andyka Kusuma

Smart City

Freight transport services cannot be separated from the infrastructure and facilities involved, each of which faces its own challenges in delivering optimal performance in the logistics sector. A common challenge in Indonesia’s road sector is the presence of overloaded freight vehicles, which has become a national issue. This phenomenon has a negative impact not only on road infrastructure but also on the environment and traffic. This study aims to develop a conceptual model of the external costs caused by truck overloading practices in terms of road infrastructure damage, increased exhaust emissions, and traffic congestion through a systematic literature review. This …


Leveraging A Centralized Fleet Assignment Management For An Aviation Resilience, Inof Seno Acton Mr., Sutanto Soehodho, Nahry Yusuf Jun 2026

Leveraging A Centralized Fleet Assignment Management For An Aviation Resilience, Inof Seno Acton Mr., Sutanto Soehodho, Nahry Yusuf

Smart City

Since deregulation in the aviation industry, competition among airlines has intensified. This competition is shown by the increasing number of routes, service times, aircraft, and airports served. This competition causes not all flight services to meet their targets, resulting in aircraft operating less efficiently. Passenger seats are not filled, and flight delays are becoming more frequent. Obviously, this will negatively impact consumers and the airline's finances. The study focused on assigning the fleet used to serve flights to maintain existing aviation services and improve aircraft operational efficiency. This study aims to maximize profits by optimizing fleet assignments through the Centralized …


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 Jun 2026

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 …


Optimization Of Sea Transportation Services In The Kepulauan Seribu Using The Vehicle Routing Problem (Vrp) Model, Darmadi Darmadi, Sutanto Soehodho, Nahry Nahry Jun 2026

Optimization Of Sea Transportation Services In The Kepulauan Seribu Using The Vehicle Routing Problem (Vrp) Model, Darmadi Darmadi, Sutanto Soehodho, Nahry Nahry

Smart City

The Kepulauan Seribu regency relies heavily on sea transportation for passenger mobility and goods distribution. However, current systems face efficiency challenges, high operational costs, and potential imbalances between demand and service capacity. This study proposes a framework to optimize sea transportation services in the Kepulauan Seribu using the Vehicle Routing Problem (VRP) method, especially the Capacitated Vehicle Routing Problem – Many Single Depot (CVRP–MSD) model with heterogeneous fleets and mixed cargo (passenger and goods). The main objective is to minimize total operating costs, which include fixed costs of using the vessel and variable travel costs, and unmet demand, both passenger …


A Portable Device To Elicit Sensory Trick And Monitor Forearm Muscle Activity In Pianists With Musician’S Dystonia, Josef Franczak Jun 2026

A Portable Device To Elicit Sensory Trick And Monitor Forearm Muscle Activity In Pianists With Musician’S Dystonia, Josef Franczak

USF Tampa Graduate Theses and Dissertations

Musician’s Dystonia (MD) is a condition that can be acquired in professional musicians,causing involuntary contractions and the loss of fine motor control. The most common pharmaceutical treatment, botulinum toxin injections, has been shown to have side effects of muscle weakness and atrophy. The sensory trick, shown to temporarily relieve symptoms of dystonia, has potential to be used as an alternative or alongside current therapies, allowing patients with MD to return to playing music professionally. To systematically deploy the sensory trick and monitor forearm muscle activity, the first prototype of the Wearable Sensorimotor Integrator (wSMI) has been developed.

The wSMI is …


Development Of A Coupled Hydrological-Nitrogen Modeling Framework For Urban Stormwater Pond Analysis, Tione Grant Jun 2026

Development Of A Coupled Hydrological-Nitrogen Modeling Framework For Urban Stormwater Pond Analysis, Tione Grant

USF Tampa Graduate Theses and Dissertations

Urbanization impacts the hydrological and biogeochemical processes that regulate water quality in downstream ecosystems, leading to increased stormwater volume and nitrogen loads in receiving aquatic environments. Although stormwater ponds are designed as simple hydraulic storage basins, they function more like managed ecosystems within urban drainage systems, offering both hydraulic attenuation and passive nutrient treatment. However, nitrogen removal efficiency varies significantly and depends on interactions between hydrological and biogeochemical factors. This thesis details the development, calibration, validation, and sensitivity analysis of a coupled hydrological-nitrogen model framework for Aaran’s Pond, an urban stormwater pond in Hillsborough County, Florida.

A process-based water budget …


Operational Feasibility Of Reinforcement Learning For Vehicle Routing Under Heterogeneous Fleet Capacity Constraints, Freddy Giovanny Aviles Moreno Jun 2026

Operational Feasibility Of Reinforcement Learning For Vehicle Routing Under Heterogeneous Fleet Capacity Constraints, Freddy Giovanny Aviles Moreno

Electronic Theses and Dissertations 2020 - Present

Reinforcement learning methods have demonstrated strong performance on vehicle routing benchmarks, yet their behavior under severe capacity constraints remains unexplored. This dissertation investigates whether PPO-based neural routing policies maintain operational viability when vehicle capacity is severely constrained, as occurs in resource-limited rural logistics settings.

Through controlled experiments on synthetic instances and validation on real-world rural healthcare networks in Florida, this research reveals a critical capacity threshold effect. Moderate capacity reductions from 40 to 20 produce negligible performance loss (4.1%), while severe reductions to capacity 10 trigger catastrophic failure with 243% degradation, manifested through degenerate single-customer routing patterns. Convergence analysis identifies …


Boiling Flow Estimation For Aero-Optic Phase Screen Generation, Jeffrey W. Utley, Gregery T. Buzzard, Charles A. Bouman, Matthew R. Kemnetz Jun 2026

Boiling Flow Estimation For Aero-Optic Phase Screen Generation, Jeffrey W. Utley, Gregery T. Buzzard, Charles A. Bouman, Matthew R. Kemnetz

Faculty Publications

Aero-optic effects due to turbulence can reduce the effectiveness of transmitting light waves to a distant target. Methods to compensate for turbulence typically rely on realistic turbulence data, which can be generated by i) experiment, ii) high-fidelity computational fluid dynamics (CFD), iii) low-fidelity CFD, and iv) autoregressive methods. However, each of these methods has significant drawbacks, including monetary and/or computational expense, limited quantity, inaccurate statistics, and overall complexity. By contrast, the boiling flow algorithm is a simple, computationally efficient model that can generate atmospheric phase screen data with only a handful of parameters. However, boiling flow has not been widely …


En-Feat: An Effective Feature Selection Method Using Ensemble Approach, Sasank Nath, Dhruba Kumar Bhattacharyya Jun 2026

En-Feat: An Effective Feature Selection Method Using Ensemble Approach, Sasank Nath, Dhruba Kumar Bhattacharyya

Mansoura Engineering Journal

Feature selection is a crucial step in machine learning and data preprocessing, significantly influencing model performance and interpretability. This paper presents a comprehensive study and contributions in the domain of feature selection by integrating traditional learning techniques with ensemble-based, proposing an effective approach. We propose a Mutual Information-based feature aggregation approach applied to union sets of features, aiming to derive an optimal subset of features that maximizes accuracy. Then, we employ an ensemble method that utilizes forward selection over union sets to identify the optimal feature subsets through sequential feature selection. Our ensemble-based feature selection method called En-feat, is evaluated …


Some New Oscillatory Behavior Of Higher-Order Elliptic Partial Differential Equations, S. Priyadharshini, V. Sadhasivam, Samrajesh Mault, K. K. Viswanathan Jun 2026

Some New Oscillatory Behavior Of Higher-Order Elliptic Partial Differential Equations, S. Priyadharshini, V. Sadhasivam, Samrajesh Mault, K. K. Viswanathan

Mansoura Engineering Journal

The main objective of this study is to investigate the new adequate conditions for oscillation of higher-order elliptic partial differential equations by using the Riccati transformation and integral average method. The Riccati transformation converts a nonlinear first order Riccati differential equation into a second order linear ordinary differential equation, enabling solution via standard linear methods followed by inversion. Our plan of action is to reduce the multidimensional problem to an ordinary differential problem by using Jensen's inequality. Elliptic partial differential equations are used in almost every field of mathematics and physics, including Lie theory, geometry, and harmonic analysis. An elliptic …


Adaptative And Structured Optimization Stockwell Transform For Robust Power-Quality Disturbances Detection, Moudjibatou Afoda, Séna Apeke, Filippo Gatti, Alessio Iovine, Léonce W. Tokam, Guy M. Toche Tchio, Ouro-Djobo S. Sanoussi Jun 2026

Adaptative And Structured Optimization Stockwell Transform For Robust Power-Quality Disturbances Detection, Moudjibatou Afoda, Séna Apeke, Filippo Gatti, Alessio Iovine, Léonce W. Tokam, Guy M. Toche Tchio, Ouro-Djobo S. Sanoussi

Mansoura Engineering Journal

The monitoring of electrical power quality requires advanced analysis techniques capable of accurately detecting and localizing non-stationary disturbances. This work proposes a structured and adaptive optimization of the Stockwell Transform (ST), referred to as Two-Power Optimization (TPO). A multiparametric Gaussian window governed by four parameters (m, p, k, r), is introduced, and a genetic algorithm is applied independently to each signal to optimize these parameters. The optimization process adapts the analysis scale to the local characteristics of the signal while preserving the physical consistency of the window function. Simulation results on synthetic power quality signals demonstrate that the proposed method …


Effect Of Rotating Cylinder On Boundary Layer Behavior And Aerodynamic Performance Of Naca 0015 Airfoil, K. Suresh, Inamul Hasan Jun 2026

Effect Of Rotating Cylinder On Boundary Layer Behavior And Aerodynamic Performance Of Naca 0015 Airfoil, K. Suresh, Inamul Hasan

Mansoura Engineering Journal

Flow separation over airfoils at moderate and high angles of attack leads to a significant degradation in aerodynamic performance. Active boundary layer control using moving surfaces provides an effective approach to delay separation and enhance lift. In this study, the aerodynamic efficiency of a NACA 0015 airfoil equipped with a rotating leading edge cylinder is numerically investigated using computational fluid dynamics. Simulations are carried out for a range of angles of attack and cylinder surface speed ratios at low Reynolds numbers like Re = 1.2 x105. The rotating cylinder injects momentum into the boundary layer, promoting flow attachment on the …


Finite Element Modelling On A Non-Linear Radiative Hybrid Nanofluid Flowing Through A Rotating Disk, N. Janaki Phani Madhuri, Md. Shamshuddin Jun 2026

Finite Element Modelling On A Non-Linear Radiative Hybrid Nanofluid Flowing Through A Rotating Disk, N. Janaki Phani Madhuri, Md. Shamshuddin

Mansoura Engineering Journal

This study develops a finite element model to investigate the MHD flow and heat transfer phenomena of Cu–H₂O and Cu–Fe₃O₄–H₂O hybrid nanofluids flow across a spinning disk modelling by the Tiwari–Das model. The governing non-dimensional momentum and energy equations account for the effects of buoyancy, nonlinear radiation, and ohmic heating. The nonlinear coupled system is solved with the element method (FEM) to find the velocity and temperature fields. Parametric studies will investigate the effects of the magnetic field, buoyancy, volume fraction of nanoparticles, and radiation. Skin friction and Nusselt number are also reported. The results show that with the hybrid …


Real-Time Iot-Enabled Dissolved Oxygen Monitoring And Automated Wastewater Recirculation In Constructed Wetlands, Sivasankar Pandiarajan, Vanitha Sankararajan, Devarinti Chandu Jun 2026

Real-Time Iot-Enabled Dissolved Oxygen Monitoring And Automated Wastewater Recirculation In Constructed Wetlands, Sivasankar Pandiarajan, Vanitha Sankararajan, Devarinti Chandu

Mansoura Engineering Journal

Wastewater treatment is necessary for environmental conservation and combating water pollution. This study demonstrates real-time dissolved oxygen (DO) monitoring in constructed wetland treatment. The system would ensure an adequate supply of oxygen through automated water circulation whenever the level is below 4 mg/L, and shut down when it reaches the normal level. From experiments conducted, it was observed that within three automated circulation processes, it is possible to increase DO concentrations from 0.5 mg/L to 5.0 mg/L. Additionally, Total Dissolved Solids reduced from 1,380 ppm to 920 ppm. pH also stabilized from 8.38 to 7.9. In this system, data is …


Bridging Machine Learning And Climate Futures: A Framework For Explainable, Self-Directed (Agentic) Ai Models In Monitoring, Mitigation, And Governance Of Anthropogenic Climate Impacts, Vijayanandh Rajamanickam, Ketaki Kulkarni, Vishwanadham Mandala, Ozgur Kisi Jun 2026

Bridging Machine Learning And Climate Futures: A Framework For Explainable, Self-Directed (Agentic) Ai Models In Monitoring, Mitigation, And Governance Of Anthropogenic Climate Impacts, Vijayanandh Rajamanickam, Ketaki Kulkarni, Vishwanadham Mandala, Ozgur Kisi

Mansoura Engineering Journal

Environmental and societal damage due to anthropogenic climate change demands detection and mitigation strategies that are both effective and accountable. Machine Learning (ML) appears to offer a powerful set of tools but remains unexploited in these areas. A key barrier remains its poor ability to draw causal inferences about external systems, an essential requirement for meaningful continued monitoring, acting on, and shaping of the climate. Explainable, self-directed learned models operate by attributing environmental changes and deciding how best to model the resulting dynamics—they offer a natural solution. Recent developments in computational ecology, meteorology, and ML are combined to propose a …


Topographical Mobility Envelope Modeling And Geometric Analysis For Off-Road Unmanned Ground Vehicles, Huashuai Fan Jun 2026

Topographical Mobility Envelope Modeling And Geometric Analysis For Off-Road Unmanned Ground Vehicles, Huashuai Fan

ETDs from 2020-2029

This dissertation introduces topographical mobility as a quantitative framework for assessing off-road unmanned ground vehicle performance based on geometric interaction between the vehicle and terrain. Rather than relying on conventional discrete indices, the proposed formulation evaluates mobility directly from vehicle and terrain geometry, expressing vehicle capability in terms of radius constraints implied by its dimensions and suspension state. On the vehicle side, longitudinal and lateral mobility radii are derived analytically from vehicle geometry—wheelbase, track width, ground clearance, and lowest underbody point location—quantifying the minimum terrain radius negotiable without underbody interference. Suspension state is shown to alter longitudinal mobility radius by …


Nitrite Oxidation During Ozonation Revisited: Mechanisms Of Nitration Reactions, Tarek Manasfi, Christoph Dieziger, Simon A. Rath, Daisuke Minakata, Urs Von Gunten Jun 2026

Nitrite Oxidation During Ozonation Revisited: Mechanisms Of Nitration Reactions, Tarek Manasfi, Christoph Dieziger, Simon A. Rath, Daisuke Minakata, Urs Von Gunten

Michigan Tech Publications

The formation of toxicologically relevant nitro compounds has been observed during ozonation of nitrite-containing secondary wastewater effluents, but their formation mechanism remains unknown. To identify key nitrating species, three reaction systems were investigated: ozonation of nitrite (O3/NO2–), peroxynitrite (ONOOH/ONOO–), and hydroxyl radical oxidation of nitrite with γ-radiolysis (γ/NO2–). Nitrite ozonation (O3/NO2–) yielded significant amounts of the nitrating agent nitrogen dioxide •NO2 (9.4% at pH 7 to 22% at pH 12) besides the main product nitrate. No peroxynitrite formation was detected during ozonation of nitrite-containing waters, suggesting that •NO2 is the …


Centrifugally Spun Silica Fibers For Lithium-Ion Battery Anodes: Structure And Cycling Stability, Alejandra Guerrero, Valeria Tirado, Jason Parsons, Mataz Alcoutlabi Jun 2026

Centrifugally Spun Silica Fibers For Lithium-Ion Battery Anodes: Structure And Cycling Stability, Alejandra Guerrero, Valeria Tirado, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

Introduction: Silicon dioxide (SiO2) fiber structures have attracted attention as alternative anode materials for lithium-ion batteries because of their ability to improve cycling stability compared to commercial silicon particles.

Materials and methods: SiO2 composite fibers were prepared by centrifugal spinning of polyvinylpyrrolidone (PVP)/SiO2 precursor solutions followed by calcination at 500–700 ◦C for different holding times to produce short-fiber composites and micro-belt SiO2 fiber structures. The morphology and crystal structure of the SiO2 short fibers and micro-belts were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS). Electrochemical performance was evaluated using CR2032 half-cells.

Results: The …


Amending Planting Media With Typha-Derived Biochar For Sustainable Horticulture, Elissa Touma Jun 2026

Amending Planting Media With Typha-Derived Biochar For Sustainable Horticulture, Elissa Touma

USF Tampa Graduate Theses and Dissertations

Constructed wetlands are widely used to improve water quality by removing excess nutrients from wastewater and stormwater. Nutrients are stored within wetland vegetation, particularly in fast-growing plants such as Typha. Harvesting vegetation provides an opportunity to permanently remove these nutrients while generating biomass suitable for beneficial reuse. Converting harvested biomass into value-added products such as compost and biochar can support nutrient recovery and sustainable biomass management. In addition, increasing concerns regarding the environmental impacts of peat extraction have created interest in renewable alternatives for horticultural growing media. Therefore, the objective of this study was to evaluate the potential of harvested …


Utilizing Waste Paper Ash As Partial Cement Replacement In Concrete, Karim Hassan Jun 2026

Utilizing Waste Paper Ash As Partial Cement Replacement In Concrete, Karim Hassan

Thesis/ Dissertation Defenses

The concrete industry has a considerable environmental impact. The manufacture of ordinary Portland cement (OPC) emits a large amount of carbon dioxide, while the extensive extraction of virgin natural aggregates further burdens the environment during concrete production. This thesis is concerned with the development of low-carbon concrete through the combined utilization of waste paper ash (WPA), recycled aggregates, and accelerated carbonation curing. The main objective is to reduce the environmental footprint of concrete products, including masonry units, by enhancing their carbon sequestration potential, decreasing the use of cement, and alleviating reliance on virgin aggregates, while also maintaining adequate mechanical and …