Engineering Science and Materials Commons^™

Effects Of Prescribed Burning On Forest Soil Low-Molecular-Weight Organic Acids, Ariana Rivera-Anazco

Honors Theses

Low-molecular-weight organic acids (LMWOAs) play important roles in nutrient mobilization, microbial activity, and carbon cycling in forest soils, yet their response to prescribed fire and thinning remains poorly understood. This thesis examined whether thinning and prescribed burning altered extractable LMWOA in O-horizon soils from the Lubrecht Experimental Forest. The study focused on lactic, propionic, glycolic, acetic, and formic acids measured in soils collected immediately before and approximately two weeks after the 2024 prescribed burn across four treatment categories: control, burn, thin, and thin+burn. The managed plots belong to a long-term experiment first treated in 2001-2002, whereas the control remained unmanaged …

Response Surface Modelling And Multi-Objective Optimisation Of Asphalt Binder And Mixture Properties Modified With Reclaimed Automotive Lubricants And Waste Glass Bottle Powder, Nura Shehu Aliyu Yaro, Jacob Adedayo Adedeji, Luvuno Nkosinathi Jele, Nasir Khan, Aliyu Usman, Jacob Olumuyiwa Ikotun

Journal of Sustainable Construction Materials and Technologies

Large volumes of reclaimed automotive lubricant (RAL) and waste glass bottle powder (WGBP) are disposed of inappropriately, causing serious environmental concerns. Furthermore, the paradigm shift towards sustainability in the pavement industry has prompted academics to investigate alternatives to conventional materials. As a result, one possible approach is to use these waste products as alternative materials in the asphalt pavement sector. This study investigated the combined use of RAL and WGBP as complementary modifiers, extending beyond the conventional single-modifier approaches reported in previous studies. Thus, in this study, response surface methodology (RSM) was utilised to optimise and predict the synergistic effects …

Design Of Air-Entrained Concrete For Airport Pavements Through Local Aggregate Utilization: Performance Optimization And Economic Analysis, Li Wentao, Rizwan Qadir, Arslan Mushtaq, Hilal Khan, Kamran Jillani

Journal of Sustainable Construction Materials and Technologies

Airport pavement construction in developing countries faces critical challenges balancing international performance standards with economic constraints, while limited research exists on optimizing air-entrained concrete mixes using locally sourced materials for cost-effective solutions. This study investigated the development of economical air-entrained concrete mix designs for airport pavements utilizing Pakistani aggregates and systematic cement content optimization. Comprehensive experimental evaluation included material characterization through petrographic analysis, alkali-aggregate reactivity assessment via accelerated mortar bar testing, and mechanical property development across cement contents from 360-450 kg/m3. Air entrainment was achieved through controlled admixture dosing while maintaining target slump of 50mm. Results demonstrated that locally sourced …

Molybdenum-Doped Zinc Oxide Nanocomposite For Sustainable Photoelectrocatalytic Degradation Of Dyes And Antimicrobial Activity, Samar A. Salim

Nanotechnology Research Centre

Mo-doped ZnO nanocomposite was synthesized by using auto-combustion method. X-ray diffraction patterns of prepared nanocomposite indicated effective construction of crystalline Mo/ZnO NCs with co-existence of MoO2 and ZnO in required weight ratio. XRD results revealed also that ZnO crystallite size decreased as Mo-doping concentration increased. The direct band gap reduced from 3.309 eV of (MZ-0) to 3.258 eV of (MZ-5), demonstrating a negative correlation with Mo-doping levels. The electrocatalytic activity of Mo/ZnO NCs was assessed by their capability to degrade Indigo Carmine (IC) and Murexide (ME) dyes, and their antibacterial properties were also evaluated. The electrocatalytic (EC) degradation efficiencies for …

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 …

Porous Hydrophobic Adsorbent Coatings For Carbon Dioxide Capture, Samuel Babatunde Olushola

Theses and Dissertations

This work presents the development of a porous, hydrophobic zeolite 13X coating for the separation of carbon dioxide (CO₂) from flue gas or natural gas. Zeolite 13X was combined with yeast, glucose, and sodium alginate as pore-forming agents, and with polytetrafluoroethylene (PTFE) and Polydimethylsiloxane (PDMS) as hydrophobicity-inducing agents to enhance water resistance while maintaining CO₂ access to the adsorbent. The study explored PTFE/13X mass ratios ranging from 0 to 2.33 to investigate the interplay between hydrophobicity and CO₂ uptake. The wettability of the coating was characterized by using a temporal water contact angle (WCA) measurement. Increasing …

Molecular Catalysts For Electrochemical Nitrogen Activation Toward Sustainable Ammonia Synthesis, Jin-Xiu Han, Hao Xue, Xian-Biao Fu

Journal of Electrochemistry

Homogeneous electrocatalytic nitrogen reduction reaction (NRR) provides a powerful framework to interrogate molecular nitrogen-fixation pathways under mild conditions. By tuning the metal center, ligand architecture, and reaction medium, these systems enable capturing key intermediates and delivering mechanistic insight at the molecular-level resolution. Nevertheless, advances remain constrained by highly reduced operating potentials, intense competition from the hydrogen evolution reaction (HER), limited durability in turnover, and inadequate long-term stability.

In this review, we take electron delivery to the molecular active site as the guiding principle for organizing homogeneous electrochemical N₂ activation and transformation. We classify reported systems into direct electron transfer …

Insertion Of Noble Metal Free Cathodic Catalyst Layer With Fe-N-C Catalyst For Boosted Performance Of Pemfc, Shi Zhou, Muhammad Tariq, Asif Nadeem Tabish, Muhammad Salman, Fan-Di Ning, Muhammad Rayyan Tayyab, Ran-Ran Peng, Meng-Geng Hao, Wen-Mu Li, Xiao-Chun Zhou

Journal of Electrochemistry

Economical Fe-N-C catalysts are considered as promising alternatives to platinum group metal catalysts for proton exchange membrane fuel cells (PEMFCs). Despite exhibiting robust activity on rotating disk electrodes, their performance within membrane electrode assemblies often experiences limitations, such as decreased O₂ diffusion, high H₂O₂ formation, low proton conduction, and a lower electron transfer number. In this study, key factors, including proton transport, electron conduction, and gas diffusion within air-breathing PEMFCs, have been investigated by adjusting cathode catalyst layer (CCL) compositions. From the experimental results, the optimal peak power density was obtained when the loading of Fe-N-C …

Water-Driven Solid Electrolyte Interphase Governs Continuous-Flow Ammonia Electrosynthesis, Peng-Bo Liu, Sheng-Liang Zhai, Ji Huang, Zhong-Shuo Zhang, Jie Zeng, Shao-Feng Li

Journal of Electrochemistry

Flow-cell architectures have emerged as a powerful platform for continuous and stable lithium-mediated nitrogen reduction (Li-NRR), enabling ambient-condition electrochemical ammonia synthesis and offering a promising alternative to Haber-Bosch processes. However, Li-NRR is exceptionally sensitive to trace water, and even minor variations in water content can profoundly alter interfacial chemistry. Here, we systematically investigate how initial water concentration affects Li-NRR performance in a continuous-flow cell. Excess water drives the formation of a thick solid electrolyte interphase (SEI) layer, which may impede nitrogen access to metallic lithium and hinder lithium-ion transport. As a result, the ammonia Faradaic efficiency collapses from ~61% to …

Design And Fabrication Of A Composite Torpedo Baseball Bat, Peyton A. Lee, Carter Mathison, Jaden J. Schwantz, Noah Misukanis, Cole V. Stalberger

Research & Creative Achievement Day

Observing current trends in Major League Baseball, there has been increasing interest in torpedo-style wood bats due to their unique weight distribution. Unlike traditional bat geometries, the torpedo design shifts more weight toward the hands, improving balance and allowing for greater control throughout the swing. This project applies the same concept using composite materials so that high school and college players can also have access to this design innovation. The proposed bat is constructed from carbon fiber reinforced polymer with an epoxy resin to create a lightweight and durable structure. The design aims to maintain the performance benefits of the …

Comparison Of Pfas-Free Hydrophobic Layer-By-Layer Coatings For Cellulosic Textiles: Evaluation Of Water Repellency, Mechanical Durability, And The Effects Of Fabric Construction, Elvira Isenzhulova, Radika Bhaskar

School of Design and Engineering Papers

Environmentally safe water-repellent coatings are urgently needed for the textile industry as an alternative to PFAS-based finishes. Challenges include development of coatings that are effective in imparting both water repellency and mechanical durability, with relatively simple synthesis to promote industry use. This study compared the performance and abrasion resistance of two different bio-based, layer-by-layer (LbL) self-assembled hydrophobic coatings for cellulosic fibers. Textile samples were coated with bilayers composed of negatively charged plant-derived carnauba wax and a positively charged component: either poly-L-lysine or lower-cost zinc oxide nanoparticles. To investigate the influence of surface microroughness on coating adhesion and performance, two different …

Analysis Of Factors Enabling Organisational Governance Maturity For The Technical Audit Function In Tanzania, George C. Haule

Tanzania Journal of Engineering and Technology (TJET)

The study aimed to identify key factors contributing to Organisational Governance Maturity (OGM) of the Technical Audit Functions (TAF) in Tanzania.  The study employed a sequential approach as a research design.  The first step was to collect and analyse literature studies to identify factors enabling the OGM of the TAF.  Next, a questionnaire was administered to one hundred twenty-eight (128) respondents from seven (7) TAFs to rank the key enabling factors that were identified from the literature that influence the OGM of TAF in Tanzania.  Using data from a questionnaire administered to 128 respondents, a two-step strategy was employed to …

Complex Systems Mapping Of Fiscal Growth Dynamics At Strategic Maritime Chokepoints Using Time-Series Slopes, Rahul Balamurugan, Preethi Nanjundan, Avichal Sharma

Northeast Journal of Complex Systems (NEJCS)

This study examines how maritime and trading states allocate public resources between defence, health, and economic growth around three strategic chokepoints the Strait of Malacca, the Strait of Hormuz, and the Suez Canal. The analysis extends the classic “guns versus butter” framing by treating defence and health spending as co-evolving components of an interconnected fiscal-growth system. Using World Development Indicators data (1999-2024), trend slopes are estimated for military spending (% of GDP), healthcare spending (% of GDP), and GDP growth (annual %). Two derived indicators are computed, a defence-to-health slope ratio (military slope/health slope) and a fiscal-balance proxy (health slope …

Hybrid Thermosetting Polymer Nanocomposite Thin Films With Optimized Thermal Conductivity And Mechanical Reinforcement, Vinicius Alvarenga, Camila M. Maroneze, Matheus S. Dias, Bruno Milton Oliveira Silva, Jaime Taha-Tijerina, Christiano J. S. De Matos, Hélio Ribeiro

Informatics and Engineering Systems Faculty Publications

Epoxy-based thin films reinforced with graphene oxide (GO), hexagonal boron nitride (h-BN), and their hybrid combination (GO/h-BN) at low filler contents (<  1 wt%) were developed to advance thermosetting nanocomposites for high-performance thermal interface materials (TIMs). The incorporation of these 2D nanostructures led to marked and simultaneous increases in both the storage modulus (E′) and the glass transition temperature (Tg) for the individual and hybrid systems. These enhancements indicated strong interfacial interactions between the nanofillers and the epoxy matrix, promoting a more efficient crosslinking density and reinforcing the overall rigidity of the polymer network. Uniform thin films, processed under controlled conditions, exhibited efficient phonon transport without compromising their dielectric integrity, as demonstrated by steady-state and 3-ω thermal analyses. The incorporation of 0.5 wt% GO/h-BN resulted in up to …

Axial Sulfur-Coordination Engineering Boosting Fe–N–C Catalysts For High-Performance Proton Exchange Membrane Fuel Cells, Lin Lin, Xiu-Xuan Hou, Zhe-Chen Fan, Yi-Xuan Yin, Wei-Yi Zhao, Kai Wei, Yu-Die Zhou, Li-Na Hou, Ying Wang, Hao Wan, Jun-Jie Ge

Journal of Electrochemistry

Fe-N-C catalysts have long suffered from kinetically sluggish oxygen reduction reaction (ORR) due to excessive adsorption strength toward oxygen intermediates and low site utilization. Heteroatom doping effectively accelerates ORR reaction kinetics through electronic structure modulation of metal sites for optimal intermediate adsorption, while chemical vapor deposition (CVD) enhances the turnover frequency (TOF) of active sites. Herein, we developed an FeSNC catalyst featuring abundant FeS₁N₄ sites via a dual-precursor CVD strategy. Experimental and theoretical analyses revealed that S incorporation disrupts the symmetric coordination of active sites, which optimizes OH* adsorption energies from 0.212 eV to 1.194 eV. Moreover, …

Deciphering The Role Of Binder Reaction Exothermicity In Thermal Runaway Of Lithium-Ion Cells, Wen Wen, Jing-Hong Zhou, Hao-Tian Lu, Xing-Gui Zhou

Journal of Electrochemistry

Thermal safety associated with lithium-ion cells as power sources remains a critical industry concern. A comprehensive understanding of how internal exothermic side reactions contribute to temperature rise is fundamental for accurately analyzing thermal runaway processes and predicting the thermal safety of lithium-ion cells. While various side-reactions, such as decomposition of solid electrolyte interphase layer, reaction between anode materials and electrolyte, reaction between cathode materials and electrolyte, and electrolyte decomposition, have been identified as heat generation sources in previous studies, the quantification of these reactions remains insufficiently standardized. Particularly, the impact of heat generation from binder decomposition (most commonly polyvinylidene difluoride) …

Ai-Scm Cmm: A Capability Maturity Model For Artificial Intelligence Integration In Supply Chain Management, Lordt Becklines, Omar F. El-Gayar, Patti Brooks, Insu Park

Annual Research Symposium

Artificial intelligence is increasingly deployed in supply chain management, yet many organizations struggle to align adoption efforts with process readiness, data quality, governance, and workforce capabilities, and they still lack validated supply chain specific roadmap for assessing readiness, sequencing investments, and reducing implementation risk. This study develops and evaluates a Capability Maturity Model for Artificial Intelligence Integration in Supply Chain Management to address that gap. Using a design science research approach, the study synthesizes prior literature and practitioner knowledge to define maturity dimensions, capability indicators, and staged progression levels for AI integration in supply chain contexts. The artifact and assessment …

Mechanical, Thermal And Fire Behaviour Of Hemp-Based Composites With Different Binders For Sustainable Building Applications, Anilcan Aygun, Fahri Birinci, Selim Aytac, Ali Kemal Ayan, Hasan Alp Sahin, Ibrahim Isildak

Journal of Sustainable Construction Materials and Technologies

This study investigates the physical, mechanical and thermal properties of hemp-based composites produced with traditional binders such as lime, cement, gypsum, clay, and water-based glue. Hemp fractions of different sizes (splinter, shiv, fiber and powder) were combined with these binders to manufacture cube and plate specimens, which were tested for physical, mechanical, thermal, and temperature resistance properties. The study aims to compare the mechanical, physical, thermal, and fire behaviour of these composites to assess their suitability for sustainable construction applications. The hemp-based composites were tested for unit weight, water absorption, compressive strength and thermal conductivity. Most specimens are lightweight (<1000 kg/m3), and exhibit good thermal insulation performance and high compressive deformability, making them suitable for seismic-prone regions. The glue-based composite had the lowest unit weight, measured as 330 kg/m3. Thermal conductivity ranged from 0.051 to 0.243 W/m· K, with several mixtures performing better than natural pumice. While cement-based composites showed the highest compressive strength, ranging from 5.5 to 24.8 kg/cm2, natural hydraulic lime is the lowest. Water absorption was high, and moisture release occurred slowly across all hemp fractions. Combustion tests indicated that hemp-based materials have moderate temperature resistance, with charring temperatures ranging from 238–265°C for raw hemp and 300–385°C when mixed with binders. Overall, hemp-based composites are lightweight, eco-friendly, and suitable for non-load-bearing construction and insulation applications. However, improvements in moisture resistance and long-term durability are necessary to enhance their practical applicability.

Sustainable Cow Dung Bricks: An Innovative Approach To Eco-Friendly Masonry With Enhanced Thermal And Mechanical Performance, Nagesh Sugandhi, Sachin Patil, Satish Reddy, Ashwini G, Santosh Kumar

Journal of Sustainable Construction Materials and Technologies

This study explores the development, characterization, and performance of sustainable cow dung bricks using locally sourced organic (cow dung) and mineral (clay, quartz sand, feldspar, lime) constituents for non-load-bearing masonry in India. Three blends with varying cow dung content (70%, 75%, 80%) were mixed, molded, air dried, and cured without kiln firing to reduce environmental impact. The bricks' mechanical properties—compressive strength, water absorption, bulk density, flexural strength, shore hardness, and modulus of elasticity—were systematically evaluated with complete statistical documentation (n = 6 replicates per formulation per test age). Microstructural features were investigated using Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray …

Sustainable Cement-Blast Furnace Slag Mortar, Richa Jain, Harshit Jain, Ashish Nim

Journal of Sustainable Construction Materials and Technologies

New building materials that required and produced less energy are need of today's infrastructure development. The ability of such building materials to promote sustainable development always puts its demand in active mode. With huge consumption of naturally occurring materials in building construction, the problem related to environment degradation is now common for world. Along with this, world is also facing the problem of reuse, recover and scientifically approved disposal of non-biodegradable wastes. Blast furnace slag (BFS) is one of those steel industry wastes that are abundantly available and their disposal arises as prime challenge for industries. This research work makes …