Preprints
Filtering by Subject: Engineering
A Systems-Level Approach to Extracting Oxygen from Lunar Regolith via Molten Regolith Electrolysis
Published: 2025-02-11
Subjects: Aerospace Engineering, Engineering, Other Planetary Sciences, Planetary Sciences
We present a top-level architecture for extracting up to 10 metric tonnes per year of oxygen from lunar regolith by means of Molten Regolith Electrolysis (MRE) using less than 30 kW from vertical solar arrays and a regolith excavator. This System Integration Study identifies specific technology which could be engineered together in the near term into a single system and lander provided focused [...]
Integration of Different Permeability Model Parameters for Permeability Prediction from Capillary Pressure Curves in Carbonate Reservoirs
Published: 2025-02-11
Subjects: Engineering
Permeability prediction is essential for reservoir characterization, commonly derived from core analysis and mercury injection capillary pressure (MICP) data. Many conventional models, often calibrated for sandstones, are based on parameters such as porosity or specific mercury saturation points, which limits their accuracy in carbonate reservoirs due to differing rock properties. This study [...]
Managing Smoke Risk from Wildland Fires: Northern California as a Case Study
Published: 2025-02-11
Subjects: Engineering, Physical Sciences and Mathematics, Social and Behavioral Sciences
Smoke fine particulate matter (PM2.5) from increasing wildfires in the western United States threatens public health. While land managers often prioritize reducing wildfire risk in the wildland-urban interface, the impact on regional air quality from mitigating wildfire spread is less explored. We develop a framework to quantify wildfire contributions to smoke exposure and assess targeted land [...]
Quantifying interfacial interactions between kerogen, water, and hydrocarbons across thermal maturity levels and their impact on fluid mobility
Published: 2025-02-07
Subjects: Engineering
Wettability of organic-rich mudrocks has significant impacts on multiphase fluid flow and hydrocarbon recovery. Since kerogen can constitute a significant volumetric fraction of mudrocks, the wettability of kerogen can considerably affect the wettability of organic-rich mudrocks. In a recent project, we showed using a combination of experimental methods and molecular simulation studies that [...]
A Comprehensive Bibliometric Analysis of Large Language Models in Hydrology and Environmental Sciences
Published: 2025-02-05
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
The application of large language models (LLMs) in hydrology and environmental sciences is expanding rapidly, but a comprehensive understanding of their potential, best practices and application areas are studied extensively. This study conducts a bibliometric analysis of recent scientific literature to evaluate publication trends, citation impact, and the key contributors in LLM-related research [...]
Most Landfill Methane Emissions Escape Detection in EPA21 Surface Emission Monitoring Surveys
Published: 2025-02-05
Subjects: Engineering, Life Sciences
We measured emissions from ten landfills using mobile surveys and Surface Emission Monitoring (SEM) to determine what fraction of emissions that be identified by SEM surveys. Using mobile methane measurements and a back-trajectory attribution and rate estimation method, we measured overall site emissions and those of individual landfill components (active face, closed cells, leachate, etc). We [...]
Microscale displacement dynamics of hydrogen and methane in fractured rock: Insights for repurposing natural gas sites for hydrogen storage
Published: 2025-01-30
Subjects: Engineering
Converting natural gas sites for hydrogen storage leverages existing infrastructure but requires understanding differences in hydrogen and methane injection/withdrawal dynamics within fractured geological formations. This study examines two-phase flow for hydrogen, methane, and their mixtures in fractured limestone from Belgium's Loenhout site. Experiments at 10 MPa and 65°C show that while [...]
Wood gasification in catastrophes: Electricity production from light duty vehicles
Published: 2025-01-28
Subjects: Engineering, Mechanical Engineering
Following global catastrophic infrastructure loss (GCIL), traditional electricity networks would be unavailable, necessitating alternative solutions to sustain critical services, such as decentralized electricity generation from wood gas. This study explores the feasibility of using modified light duty vehicles to self-sustain electricity generation by producing wood chips for wood gasification. [...]
Controls on Runoff Efficiency and its Spatiotemporal Variability in South Asian River Basins
Published: 2025-01-22
Subjects: Engineering, Physical Sciences and Mathematics
Runoff efficiency (RE) represents the potential of a basin to generate runoff in response to precipitation and it varies based on climatology and physiography. It is a key metric that enables hydrologists to compare the hydrologic responses of basins across diverse climates and landscapes. In the large river basins of South Asia, RE plays a key role in floods and drought dynamics but has not been [...]
Recent rise of water levels of Lake Nakuru, Kenya: Unraveling the Changing Precipitation Regime and its Climatic Drivers
Published: 2025-01-21
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Engineering, Environmental Engineering, Meteorology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology
The Kenyan Rift Valley has experienced an abrupt and significant rise in its lake levels since 2010, followed by a more rapid rise since 2020. This paper examines the dynamic changes in precipitation patterns and their climatic drivers in the Kenyan Rift Valley region from 1981 to 2021, focusing on Lake Nakuru. Notably, in 2010, a pivotal change point in precipitation aligns with the rising water [...]
On the Definition of an Independent Stochastic Model for InSAR Time Series
Published: 2025-01-16
Subjects: Engineering, Physical Sciences and Mathematics
InSAR enables the estimation of displacements of (objects on) the Earth’s surface. To provide reliable estimates, both an independent stochastic and functional model are re- quired. However, the intrinsic problem of InSAR is that both are unknown. Here we propose an independent definition of the stochastic model, via an approximation scheme for the variance- covariance matrix for [...]
AI-Driven Decision-Making for Water Resources Planning and Hazard Mitigation Using Automated Multi Agents
Published: 2024-12-27
Subjects: Civil Engineering, Computational Engineering, Computer and Systems Architecture, Computer Engineering, Ecology and Evolutionary Biology, Education, Engineering, Environmental Engineering, Geotechnical Engineering, Higher Education, Hydraulic Engineering, Operations Research, Systems Engineering and Industrial Engineering, Risk Analysis, Scholarship of Teaching and Learning, Systems Engineering, Terrestrial and Aquatic Ecology, Transportation Engineering
This project simulates the Multi-Hazard Tournament (MHT) framework, a decision support system designed for the U.S. Army Corps of Engineers, using AI agents to enhance decisionmaking processes for flood mitigation and water resource management. The objective of the framework is to develop optimal strategies for protecting water resources, habitats, and communities within a defined budget. The [...]
Improved Streamflow Simulations in Hydrologically Diverse Basins using Physically Informed Deep Learning Models
Published: 2024-12-23
Subjects: Civil Engineering, Engineering, Hydrology
Physically informed deep learning models, especially Long Short-Term Memory (LSTM) networks, have shown promise in large-scale streamflow simulations. However, an in-depth understanding of the relative contribution of physical information in deep learning models has been missing. Using a large-sample testbed of 220 catchments in hydrologically diverse regions of the Indian subcontinent, we [...]
Unlocking Geological Hydrogen Storage with Ammonia: An Effort for Net-Zero Future
Published: 2024-12-21
Subjects: Education, Engineering
Hydrogen gas (H2) generation systems, comprising carbon capture and storage technology (CCST) play a crucial role to achieve the U.N. Net Zero goal before 2050. However, a critical challenge in grid-scale H2 storage is the low volumetric energy density. One prospective approach is to use ammonia (NH3) as a chemical carrier for H2 and store it. This paper presents a state-of-the-art report on NH3 [...]
Distributed Acoustic Sensing (DAS) for Longwall Coal Mines
Published: 2024-12-19
Subjects: Engineering
Seismic monitoring of underground longwall mines can provide valuable information for managing coal burst risks and understanding the ground response to extraction. However, the underground longwall mine environment poses major challenges for traditional in-mine microseismic sensors including the restricted use of electronics due to potentially explosive atmospheres, the need to frequently and [...]