Digital Commons Network^™

The Pure Water Project, Colton Casey, Anna Engelman, Abby Strobel

Sustainability Conference

After earthquakes devastated Haiti in 2010, a team of Embry-Riddle students and faculty built and installed a solar-powered water purifier to improve both the environmental and human health concerns created by the lack of infrastructure, clean water, and sanitation. Since then, the group Pure Water Project has installed 12 water purifiers in orphanages, clinics, schools, and community centers in Haiti and the Dominican Republic. The group relies on its partner selection criteria and local contacts to determine the installation site for the purifier. The fall and spring semester leading up to the installation trip in May are spent designing, building, …

A Macroergonomic Analysis Of Autonomous Robotic Construction For Affordable Housing, Ricardo Leon Jimenez

Sustainability Conference

As communities seek to increase housing supply, the construction sector continues to grapple with rising costs, skilled labor shortages, and growing pressure to improve environmental sustainability. Meeting these demands will require new approaches that increase productivity while lowering environmental impact throughout the building lifecycle. Recent advances in autonomous systems developed for space exploration offer alternative ways to design, assemble, and maintain residential buildings. This study examines the potential application of NASA's Automated Reconfigurable Mission Adaptive Digital Assembly Systems (ARMADAS) technology from space construction to terrestrial affordable housing construction.

While most construction automation research focuses on technical performance, this study considers …

A Performance-Based Indicator Framework For Assessing Innovative Materials In Modular Emergency Shelters, Riham Nady Faragallah, M. S. Refaey, Naglaa M. Yussuf, Riham S. Hassan

HBRC Journal

In recent years, the increasing intensity of disasters, conflicts and mass displacement has amplified the need for emergency shelters that are rapidly deployable, structurally safe, and thermally comfortable, particularly when delivered through prefabricated modular systems. The recent development of innovative materials—including smart, recycled, bio-based, and 3D-printed composites—has demonstrated considerable potential for improving emergency shelter performance. However, existing studies primarily evaluate these materials individually, with limited efforts to integrate them into a comprehensive performance-based decision framework for modular emergency shelters. This research aims to develop a performance-based indicator framework for evaluating and selecting innovative materials to enhance the safety, comfort, durability, …

Adaptive Improved Particle Swarm Optimization-Based Maximum Power Point Tracking And Energy Smoothing For Photovoltaic Hybrid Battery–Supercapacitor Storage Systems, Mohammad Aminul Islam, Guo Shaokai, Jakaria Mahdi Imam, Mohammad Khairul Basher, Nowshad Amin, Tarek Abedin, Mohammad Nur-E-Alam

Research outputs 2022 to 2026

The rapid development of photovoltaic (PV) systems has made them an important component of the global clean energy strategy. However, the intermittency and non-linear characteristics of photovoltaic (PV) output remain major challenges for stable renewable energy utilization. This study proposes an adaptive improved particle swarm optimization (IPSO)-based maximum power point tracking (MPPT) strategy integrated with hybrid energy storage coordination for photovoltaic systems. The IPSO introduces adaptive inertia adjustment, velocity clamping, and stagnation reinitialization, which improve the convergence robustness under dynamic irradiance and temperature conditions. The algorithm was benchmarked against Perturb & Observe (P&O), Incremental Conductance (INC), and standard PSO using …

Two-Stage Stochastic Programming For Resource Allocation In Mobile Underwater Acoustic Networks, Sadaf Vahabli, Iftekhar Ahmad, Quoc Viet Phung, Daryoush Habibi

Research outputs 2022 to 2026

Underwater Acoustic Networks (UANs) enable long-range communication for a range of applications. However, UANs are severely limited by scarce acoustic spectrum, which is shared with marine animals and can lead to disruptive interference, contributing to anthropogenic ocean noise. In addition, the underwater environment is highly dynamic, where: marine-animal presence is uncertain, channel conditions fluctuate, and Doppler effects degrade communication reliability. Prior UAN studies have addressed these challenges separately, despite their combined effect on resource allocation. Accordingly, this paper proposes a two-stage Scenario-based Stochastic Programming (SSP) framework with a hybrid risk approach that jointly treats these challenges within a single resource …

Education Before Electricity: Ai-Facilitated Capability Formation As A Pre-Condition For Productive Energy Use In Off-Grid Communities, Kevin Hallinan, Lu Hao, Bennywhite Davidson, Divinegift Morris, Confidence Onuahu, Silas Clergy

Mechanical and Aerospace Engineering Working Papers

Solar microgrids in sub-Saharan Africa routinely fail to generate the productive demand needed to service their investment, because the capability to convert electricity into economic activity does not exist at electrification. We report a 15-month deployment in Oloibiri, Nigeria, a community whose productive base was displaced by oil extraction, testing whether AI-facilitated learning can build that capability at a cost compatible with microgrid investment.

The Davidson AI Innovation Center enrolled 104 learners (136 accounts) with zero prior computer access. They recorded 4,134 learning sessions, and 25 individuals earned 90 certifications on unscaffolded work, for just over $20,000 in cumulative investment, …

Electrocatalytic Oxidation Of Ethylene Glycol To Glycolic Acid: From Mechanism And Catalyst Design To Emerging Neutral Electrolyte Systems, Man Zhang, Xue Li, Xin-Yu Peng, Lin Wang, Wen-Wen Chen, Yao-Yue Yang

Journal of Electrochemistry

Polyethylene terephthalate (PET) waste represents both an environmental burden and a loss of carbon resources. Alkaline depolymerization of PET yields terephthalic acid and ethylene glycol (EG). Electrocatalytic oxidation of EG to glycolic acid (GA), the monomer of biodegradable polyglycolic acid (PGA), offers a sustainable route driven by renewable electricity. However, the ethylene glycol oxidation reaction (EGOR) involves competing pathways toward C2 products (GA and oxalic acid) and C1 products (formic acid and CO₂), making selective GA production a central challenge. This review provides a comprehensive overview of recent progress in selective EG-to-GA electrooxidation from catalyst design, mechanistic understanding, …

Regularization-Based Crystallite Size Distribution Analysis Of Pt/C Catalysts From X-Ray Diffraction, Cheng-Long Ma, Wei-Yu Shi, Zhong-Jun Hou

Journal of Electrochemistry

Accurate determination of the platinum crystallite size distribution in carbon-supported platinum (Pt/C) catalysts is critical for evaluating both the initial performance and long-term durability of proton exchange membrane fuel cells (PEMFCs). Conventional characterization approaches—including transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and the Scherrer equation—are limited by restricted statistical sampling, sensitivity to support interference, or the inability to resolve the full breadth of the size distribution. In this work, we present a regularization-based inversion framework that extracts the volume-weighted crystallite size distribution directly from X-ray diffraction (XRD) line profiles, without requiring any a priori assumption regarding the functional form …

Metal Oxide Semiconductor Gas Sensors For Exhaled Breath Cancer Biomarker Detection, Guang-Lan Chen, Hui-Hui Luo, Wen-Wen Peng, Shi-Yu Xu, Yu-Ting Li, Hui-Jie Ke, Si-Hui Zhong, Jia-Ao Wei, Tong Chen, Xiao-Kun Li, You-Lin Zhang, Wei Chen

Journal of Electrochemistry

Early cancer screening can significantly improve therapeutic outcomes, volatile organic compounds (VOCs) and other related gases in exhaled breath, as cancer-specific biomarkers, offer a novel approach for non-invasive diagnosis. Metal oxide semiconductor (MOS)-based gas sensors are pivotal for exhaled breath VOCs detection, featuring compact size, cost-effectiveness, and rapid response. This review summarizes the most recent five-year research advances in cancer biomarker detection, and clarifies the core mechanisms of electrical property changes from sensing material-VOCs interactions and key performance metrics including sensitivity, selectivity, humidity tolerance, response/recovery time, stability, and operating temperature. This review also highlights the optimization strategies of sensing materials …

Influence Of Particle Properties And Grain Size On Aggregation In Dry Particle-Laden Volcanic Jets, Md Miraz Hossain, Stephen A. Solovitz, Josef Dufek, Joshua S. Mendez Harper, Alexa R. Van Eaton, Mary C. Benage, Larry G. Mastin, Benjamin J. Andrews

Electrical and Computer Engineering Faculty Publications and Presentations

Explosive volcanic eruptions can inject large amounts of ash into the atmosphere. These suspended particles pose hazards to aircraft, so a better understanding of the ash residence time and transport distance is needed. Fine particles combine to form larger aggregates, altering their settling behavior. Ash aggregation is influenced by liquid bonding, electrostatic forces, and preferential concentration driven by turbulence. We examine particle aggregation through controlled, low-humidity experiments at similar particle-fluid scaling to conditions near a volcanic vent. Particle-laden jets used compressed air containing three types of particles at controlled mass loadings: hollow glass spheres (∼10 μm diameter), solid nickel spheres …

Beyond Probability: An Analytical Exploration Of Fuzzy And Neutrosophic Paradigms In Binomial Acceptance Sampling, Uma G, Vela Muruga Anurahini P

Neutrosophic Systems with Applications

Acceptance sampling plans are widely used in Statistical Quality Control to determine the acceptance or rejection of production lots based on sample inspection. Classical sampling plans under the binomial distribution assume precise parameter values, which may not adequately represent uncertainty, vagueness, and indeterminacy encountered in practical inspection environments. This review summarizes acceptance probability formulations for single and double sampling plans developed using fuzzy and neutrosophic logic under the binomial distribution. The focus is on studies that model the fraction defective and related parameters as fuzzy or neutrosophic numbers, allowing imprecise and indeterminate quality information to be incorporated into sampling decisions. …

Reliability-Calibrated Q-Rung Orthopair Neutrosophic Soft Ranking Under Partial Observability: An Auditable Industrial-Process Benchmark, Nagham Ahmed Abdelmegeed, Zeshan Aslam Khan

Neutrosophic Systems with Applications

Multi-criteria decision systems often interpret disagreement among criteria as evidence that some criteria are unreliable. This is problematic when the disagreement reflects a genuine operational trade-off. We develop a reliability-and-admissibility-calibrated q-rung orthopair neutrosophic soft ranking procedure (RAC-qRON) that distinguishes recorded evidence quality from the direction of criterion preferences. An explicitly bounded interval for each alternative–criterion observation is mapped to truth, indeterminacy and falsity memberships, with an admissibility proof for every integer rung q ≥ 1. Criterion weights are adjusted according to recorded information coverage rather than cross-criterion correlation, and a fixed-reference ideal-distance calculation produces an auditable rank. The method is …

Risk Prioritization Of ``Digital Drug'' And Consumer Neurostimulation Modalities: A Reproducible Interval-Valued Fermatean Fuzzy Entropy–Topsis Framework, Rawan Emad El-Saadany, Ahmed Samy, Mohamed M. Abdelhafeez, Mahmoud M. Ismail

Neutrosophic Systems with Applications

Consumer audio and multisensory stimulation technologies are increasingly accessible through streaming platforms, mobile applications, and immersive media. The expression digital drug is sometimes used for binaural-beat content intended to alter subjective states, but the term is a consumer/cultural label and does not imply pharmacological equivalence. Risk prioritization in this area is difficult because evidence is heterogeneous, several relevant criteria are qualitative, and judgments may be imprecise rather than point-valued. This paper develops a transparent interval-valued Fermatean fuzzy (IVFF) group decision framework that combines interval-preserving aggregation, Shannon entropy weighting, and TOPSIS for prioritizing digital drug risk scenarios under uncertainty. The method …

Risk-Based Cybersecurity Threat Prioritization In Digital Twin-Enabled Cyber-Physical Systems, Nada Mohamed, Alshaimaa A. Tantawy, Ahmed M. Abdelmouty

Neutrosophic Systems with Applications

Digital Twin (DT)-enabled cyber-physical systems (CPS) face cybersecurity risks due to their complex connections and high levels of interdependence. Traditional methods, for assessing risk often fail to rank these threats. This is especially true when expert opinions include ambiguity, uncertainty or unclear information. A Type 2 Neutrosophic Entropy– Measurement of Alternatives and Ranking according to COmpromise Solution (Entropy- MARCOS) framework for cybersecurity threat prioritization in DT-enabled CPS is proposed in this paper. The uncertainty and indeterminacy present in expert evaluations are represented by Type 2 Neutrosophic Numbers (T2NNs). While the MARCOS technique is used to assess and rank cybersecurity threats …

Context-Regulated Q-Neutrosophic Soft Model Selection Under Input Perturbation: Evidence From Three Classification Benchmarks, Poom Kumam, Supak Phiangsungnoen

Neutrosophic Systems with Applications

Selecting a classifier using a single average metric can conceal instability across validation splits, poor lower-tail behavior, and sensitivity to input perturbations. This study formulates a context-regulated Q-neutrosophic soft model-selection procedure with two fixed evaluation conditions. For each classifier and performance criterion, mean attainment (truth), across-split dispersion (indeterminacy), and the complement of a lower empirical quantile (falsity) form an auditable three-component descriptor. A bounded lower-context regulator aggregates their penalized utilities; monotonicity and perturbation bounds follow directly from its convex representation. Four fixed classifiers are compared using five benefit-oriented criteria, three repetitions of stratified five-fold cross-validation, and paired test-feature perturbations. Three …

Integrated Automation Framework For Generation Retirement Studies In Transmission Planning, Mohammed Sleiman, Tianwei Xia, Zhangxin Zhou, Nathaniel Rice

Electrical and Computer Engineering Faculty Research & Creative Works

Generation retirement studies are a critical part of long-term transmission planning, as power systems transition toward higher penetration of renewable energy and the retirement of conventional generation. However, existing study workflows are often fragmented across multiple tools and platforms such as PSS/E, TARA, Python, and Excel resulting in time-intensive processes, limited scalability, and reduced reproducibility. This paper showcases an integrated automation tool developed for generation retirement studies that is designed to streamline and unify the end-to-end analytical workflow.

The proposed framework consolidates key study components, including generator retirement modeling, power flow redispatch, contingency analysis (N-1 and N-1-1), and mitigation cost …

Nitrate Plants Nominees To The Alabama Engineering Hall Of Fame Correspondence From William K. Rey, Oct. 3, 1988, William K. Rey

Correspondence

Correspondence from Chairman William K. Rey to William Lindsey McDonald confirming the nomination of the Nitrate Plants in North Alabama to the Alabama Engineering Hall of Fame.

Connecting Bim And Gis Through Bsdd: Automating Gis Data Templates And Semantic Mapping - Research Explainer, Hamza Tariq, Ciaran Mcnally

Reports

This research explainer examines how the buildingSMART Data Dictionary (bSDD) can support greater interoperability between Building Information Modelling (BIM) and Geographic Information Systems (GIS).

Drawing on research presented at the 2026 Civil Engineering Research in Ireland conference, it explores practical approaches to automatically generating standardised GIS data templates, mapping existing asset information to common data definitions, and validating information against agreed requirements.

The explainer demonstrates how open standards and structured data can improve information quality, reduce manual processing and support more consistent asset information management throughout the asset lifecycle.

Magnetic Cellulose Nanocrystal Composites Functionalized With Benzalkonium Chloride For Potential Pathogen Control, Kishore Chand, Sydney Herzog, Mohammad Jahid Hasan, Juganta Roy, Moses Ayitey-Adjin Jr., Corbon M. Moss, Sarah Khan, Sara Tester, Monishita Deb, Katherine Schlaak, Sarah Watzman, Yvonne Sun, Esteban Ureña-Benavides, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

This study presents the design and synthesis of multifunctional magnetic cellulose nanocrystal (CNC) composites engineered for targeted adsorption and broad-spectrum antimicrobial applications. The nanocomposites were fabricated by anchoring mixed-valence Fe₃O₄ magnetic nanoparticles on eco-friendly CNC frameworks, followed by surface functionalization with benzalkonium chloride (BC), a potent quaternary ammonium biocide. Both sulfated (S) and TEMPO-oxidized CNC (T) variants were investigated across Fe₃O₄:CNC mass ratios of 1:2 and 1:4. Comprehensive structural, magnetic, and morphological characterization confirmed successful surface modification, superparamagnetic responsiveness, and uniform component dispersion. Thermogravimetric analysis confirmed precise compositional tailoring, capturing up to 87 …

Comparative Performance Evaluation Of Generative Ai-Assisted Acoustic Tiles From Recycled Educational Waste, Nada Ahmed Talaat, Ahmed Mahmoud Elfakarany, Nihal Atif Salim

HBRC Journal

Noise pollution is increasingly recognized as a critical environmental challenge with direct implications on public health and well-being. In Egypt, data from the Egyptian Environmental Affairs Agency (EEAA, 2019) identify noise as the second most reported environmental concern, affecting both indoor and outdoor spaces. At the same time, the growing volume of waste generated on university campuses represents an underexploited resource for sustainable design. This study addresses these challenges by investigating how generative AI can serve as a design collaborator in suggesting high-performance acoustic tiles from recycled campus waste. Two AI-driven prototypes were developed through prompts emphasizing acoustic absorption, aesthetic …

50 Years Of Irrigation District Modernization In The Usa -- Then And Now, Charles M. Burt

BioResource and Agricultural Engineering

Irrigation district modernization in the USA has seen changes in management attitudes, hardware, software, and the shouldering of responsibilities for environmental issues that were never envisioned fifty years ago. The pace of modernization is quite variable depending upon the state and location within the state. This paper provides some insights into the evolution of several aspects of modernization over that fifty year time span.

Comprehensive Variable-Temperature Raman And Spectroscopic Ellipsometry Investigation Of Bulk Undoped, Fe-Doped, And Ge-Doped Gan: Correlated Phonon, Carrier, Optical, And Disorder Dynamics, Manika Tun Nafisa, Sm Atiqur Rahman, Zhe Chuan Feng, Sandip Das, James N. Hilfiker, Nina Jong, Ian T. Ferguson, Benjamin Klein

Faculty Articles

Bulk gallium nitride (GaN) substrates with controlled electrical compensation and doping are foundational materials for high-power electronics, optoelectronics, and emerging spintronic devices. Despite extensive studies on epitaxial GaN thin films, a complete and correlated understanding of crystal, phonon, free-carrier, birefringence, optical, and disorder-driven processes in high-quality bulk GaN crystals remains limited. In this work, a comprehensive temperature-dependent (25–300 °C) investigation of free-standing bulk undoped, Fe-doped, and Ge-doped GaN substrates using Raman spectroscopy, spectroscopic ellipsometry (SE), and atomic force microscopy (AFM) has been presented. A detailed analysis of phonon evolution, apparent Raman-shift-derived biaxial stress and in-plane strain, longitudinal optical phonon–plasmon coupling …

Propuesta Metodológica Para La Evaluación De La Pobreza Energética En Chiapas, México, Mario Alejandro Sánchez Trujillo, Pascual López De Paz, Marcelino García Benítez, Amina El Mekaoui, Bassam Alí, Jesús Francisco Escalante Euán

Journal of Maya Heritage

Resumen. El acceso inequitativo e insuficiente a servicios energéticos de calidad constituye uno de los principales obstáculos para el desarrollo socioeconómico y el bienestar humano en México, siendo el estado de Chiapas una de las entidades con mayor vulnerabilidad socioambiental. Este trabajo presenta una propuesta metodológica cuantitativa y geoespacial para evaluar la pobreza energética de las siete subprovincias fisiográficas de Chiapas. La metodología combina datos de censos de población y vivienda 2020 (INEGI), la estandarización Min-Max, el análisis de correlación de Pearson y el análisis de componentes principales (PCA) para la construcción de un índice de pobreza energética (IPE) multidimensional. …

Forging “The Backbone Of The Blue Sky”: Pathways For Enhancing Independent Innovation Capability Of China’S Commercial Aircraft Industry, Qianshu Shi, Chao Zhang, Quan Cheng

Bulletin of Chinese Academy of Sciences (Chinese Version)

Advancing indigenous innovation in China’s commercial aircraft industry is essential for strengthening the country’s high-end equipment manufacturing capabilities and enhancing the technological self-reliance of its aviation sector. China has achieved notable progress in key technological breakthroughs, industrial system development, and commercial operational validation. Nevertheless, gaps remain between China and the world’s leading aviation powers, owing primarily to an insufficient supply of original advances from fundamental research, underdeveloped mechanisms linking collaborative innovation activities, limited capacity for the independent iteration of core systems, and inadequate accumulation of lifecycle data. Strengthening fundamental aeronautical research is therefore critical to overcoming these constraints. Drawing on …

Breaking Through Bottleneck In Overseas Expansion Of China’S Commercial Aircraft: Pathways For Business Model Innovation, Mengru Dong, Chaofeng Huang, Chao Zhang

Bulletin of Chinese Academy of Sciences (Chinese Version)

The overseas expansion of China’s commercial aircraft is a strategic choice for building manufacturing power, transportation power, and aviation powerhouse. Business model innovation serves as a crucial means to enable these aircraft to overcome international competition barriers and accelerate their overseas expansion. Based on the analysis of the urgency of the overseas expansion of China’s commercial aircraft and the necessity of business model innovation, this study systematically reviews the main business models for the overseas expansion of global commercial aircraft, including the complete aircraft sales model, the collaborative operation model, and the full life cycle service model. Furthermore, based on …

Current Status, Challenges, And Countermeasures For Airworthiness Certification Of China’S Large Homegrown Aircraft, Liming Ge, Mingda Yang, Zixuan Liu, Yichen Wang, Jing Deng

Bulletin of Chinese Academy of Sciences (Chinese Version)

The airworthiness certification of domestically produced large aircraft serves as both a crucial foundation for achieving self-reliance and independent control over China’s aviation industry chain and a key support for deep participation in the governance of global civil aviation rules. Currently, the airworthiness certification system has taken initial shape, localized infrastructure networks are gradually improving, and the benefits of a super-large market are continuously being realized, effectively facilitating the successful large-scale commercial operation of the C919 airplane. The development of domestic large aircraft families places greater demands on certification resource coordination and airworthiness management throughout the aircraft life cycle. However, …

International Experiences, Lessons, And Implications For Development Of Commercial Aircraft Industry, Chaofeng Huang, Cuilin Wu

Bulletin of Chinese Academy of Sciences (Chinese Version)

The commercial aircraft industry serves as a cornerstone for building a strong aviation country, a new engine driving economic growth, and a core carrier for upgrading the aviation industrial structure. Over more than 70 years of global industrial evolution, commercial aircraft development programs in most countries have encountered bottlenecks and withdrawn from the market, resulting in a duopoly dominated by the United States and Europe, which has accumulated abundant practical experience and historical lessons. At present, China’s commercial aircraft industry has entered a new phase of large‑scale production and international expansion. Nevertheless, it still faces challenges including bottlenecks in key …

China’S Semiconductor Supply Chain Landscape And Strategies For Enhancing Global Competitiveness, Su Zhang, Ziyan Yang, Yifan Sun, Yan Xia, Huijuan Wang

Bulletin of Chinese Academy of Sciences (Chinese Version)

Against the backdrop of accelerating global digital transformation, intelligent upgrades, and intensifying geopolitical competition, the semiconductor supply chain has become the focal point of global technological, economic, and security dynamics. This study systematically examines the evolution of the global semiconductor supply chain, assesses security risks in China’s semiconductor industry, and analyzes the impact of China-US semiconductor decoupling using a hypothesis extraction approach. Based on these findings, it proposes strategic pathways to enhance China’s semiconductor competitiveness. Key findings include the following: (1) The global semiconductor supply chain exhibits both “regional concentration” and “industry fragmentation”. The US and Europe dominate upstream segments, …

Integrating Tacit And Explicit Knowledge Across Construction Projects: A Qualitative Evidence Synthesis Of Knowledge Transfer, Lessons Learned, And Organizational Learning, Felix M. Delmonte

Mechanical and Civil Engineering Faculty Publications

Abstract

Construction projects rely on knowledge distributed among temporary, multidisciplinary teams, firms, and lifecycle stages. Practical judgment often remains with experienced participants, while written accounts may omit the conditions and reasoning needed for later use. This research examines how construction scholarship explains the movement of project knowledge from capture through sharing and retrieval to reuse on another project. It treats these activities as distinct, and considers tacit expertise alongside explicit records, with attention to who contributes knowledge, who needs it, and where it must travel. The planned approach is a qualitative synthesis of published, peer-reviewed research from 2022–2026. The available …

Source Page Evaluation Of Local Rag Retrieval For Engineering Safety: Implications For Mechanical And Civil Engineering, Sherif Sorour, Areej El Mufti, Mohamed Nabawy, Anwar Sahbel

Civil Engineering

Industrial safety question answering requires access to the exact source material that supports an answer, not merely a related document. This study evaluates the retrieval stage of a local retrieval-augmented generation (RAG) system at the source page level. Eighteen documents on lockout/tagout, machine guarding, and personal protective equipment were prepared in raw, cleaned, and metadata-enriched forms. Best Matching 25 (BM25), latent semantic analysis (LSA), and reciprocal rank fusion (RRF) hybrid retrieval were tested on 54 questions: 36 answerable, 12 safety-related but unsupported, and 6 outside the covered topics. Raw BM25 achieved the highest mean reciprocal rank (0.492) and Hit@5 (0.722), …