Filtering by Subject: Engineering
Published: 2021-02-25
Subjects: Engineering
Brines located in the Salar de Atacama are a significant source of lithium worldwide. The extractive method for these minerals is through brine pumping, with subsequent solar evaporation in ponds. In this latter process, part of the water present in brine is evaporated to the atmosphere, leading to the possibility of harvesting lithium and potassium salts. This situation has risen a series of [...]
Published: 2021-02-24
Subjects: Engineering
There is a growing interest in developing data-driven subgrid-scale (SGS) models for large-eddy simulation (LES) using machine learning (ML). In a priori (offline) tests, some recent studies have found ML-based data-driven SGS models that are trained on high-fidelity data (e.g., from direct numerical simulation, DNS) to outperform baseline physics-based models and accurately capture [...]
Published: 2021-02-24
Subjects: Civil and Environmental Engineering, Construction Engineering and Management, Earth Sciences, Engineering, Environmental Engineering, Environmental Health and Protection, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Sustainability, Water Resource Management
Heat-related mortality and flooding are pressing challenges for the >4 billion urban population worldwide, exacerbated by increasing urbanization and climate change. Urban greening, such as green roofs and parks, can potentially help address both problems, but the geographical variation of the relative hydrological and thermal performance benefits of such interventions are unknown. Here we [...]
Published: 2021-02-23
Subjects: Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Engineering, Environmental Engineering
Methane is emitted and flared from industrial sources across the United States, contributing to global climate change. This need not be the case. Methanotrophic (methane-oxidizing) bacteria can transform methane into useful protein-rich biomass (e.g., to replace fishmeal in animal feeds). Here, we analyze the economic potential of producing methanotrophic microbial protein from methane emitted [...]
Published: 2021-02-19
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering
The height above nearest drainage (HAND) model is frequently used to calculate properties of the soil as well as predict flood inundation extents. HAND is extremely useful due to its lack of reliance on prior data, as only the digital elevation model (DEM) is needed. It is close to optimal, running in linear or linearithmic time in the number of cells depending on the values of the heights. It [...]
Published: 2021-02-14
Subjects: Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Geology, Geomorphology, Glaciology, Hydrology, Numerical Analysis and Scientific Computing, Other Environmental Sciences, Physical Sciences and Mathematics, Sedimentology, Soil Science, Stratigraphy
Computational modelling occupies a unique niche in Earth environmental sciences. Models serve not just as scientific technology and infrastructure, but also as digital containers of the scientific community's understanding of the natural world. As this understanding improves, so too must the associated software. This dual nature---models as both infrastructure and hypotheses---means that [...]
Published: 2021-02-10
Subjects: Engineering, Physical Sciences and Mathematics
Crop phenology of alfalfa and grass pasture fields on the western slope of Colorado, USA, was tracked using an NDVI time series derived from Landsat 7 (ETM+), Landsat 8 (OLI) and Sentinel 2a MSI to obtain high temporal frequency information of crop growth stages. These perennial pastures, which occupy a majority of irrigated land in the region and typically have more than one growing/cutting [...]
Published: 2021-02-10
Subjects: Engineering, Physical Sciences and Mathematics
The Comparison Model Method (CMM) is a relatively simple and computationally efficient direct method for the identification of the transmissivity of a confined aquifer by solution of an inverse problem. However, it suffers some of the classical drawbacks related to ill-posedness and ill-conditioning of inverse methods. Effectiveness of the CMM can be improved by some approaches. First of all, the [...]
Published: 2021-01-30
Subjects: Engineering, Life Sciences, Social and Behavioral Sciences
Human foot traffic in urban environments provides essential information for city planners to manage the urban resources and urban residents to plan their activities. Compared to camera or mobile-based solutions, seismic sensors detect human footstep signals with fewer privacy concerns. However, seismic sensors often record signals generated from multiple sources, particularly in an urban outdoor [...]
Published: 2021-01-28
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geomorphology, Hydraulic Engineering, Physical Sciences and Mathematics, Sedimentology
Upper Mississippi River flow and sediment characteristics downstream of St. Louis are presented in this study. Available and measured data were used to assess a harbor siltation case and dredging needs. Such data are also useful to researchers and engineers conducting work in the Mississippi River and large rivers in general. Flows were characterized in terms of the mean annual hydrograph, flow [...]
Published: 2021-01-17
Subjects: Engineering, Fluid Dynamics, Hydraulic Engineering, Oceanography, Statistical Models
Regarding wave statistics, nearly every known exceeding probability distribution applied to rogue waves has shown disagreement with its peers. More often than not, models and experiments have shown a fair agreement with the Rayleigh distribution whereas others show that the latter underpredicts extreme heights by almost one order of magnitude. Virtually all previous results seem to be [...]
Published: 2021-01-16
Subjects: Engineering
Nearly four decades have elapsed since the first efforts to obtain a realistic narrow-banded model for extreme wave crests and heights were made, resulting in a couple dozen different exceeding probability distributions. These models reflect results of numerical simulations and storm records measured off of oil platforms, buoys and more recently satellite data. Nevertheless, no consensus has been [...]
Published: 2021-01-16
Subjects: Engineering, Physical Sciences and Mathematics
Strain transfer analysis is an important means of correcting the measurement error of embedded or surface-bonded distributed fiber-optic sensors, but the effect of host strain patterns has not been well elucidated. Here, a theoretical model for strain transfer analysis of surface-bonded multi-layered fiber-optic sensor subjected to a linear gradient strain was established. Closed-form solutions [...]
Published: 2021-01-13
Subjects: Engineering
Understanding and predicting shoreline changes is paramount to coastal managers to anticipate potential threats. These shoreline changes are often driven by complex processes at multiple timescales. In this paper, a new approach to model wave-driven, cross-shore shoreline change incorporating multiple timescales is introduced. As a base we use the equilibrium shoreline prediction model ShoreFor [...]
Published: 2021-01-06
Subjects: Applied Mathematics, Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Computer Sciences, Engineering, Physical Sciences and Mathematics, Planetary Sciences
This work presents the implementation of the LOTOS-EUROS regional atmospheric Chemical Transport Model (CTM) on Northwestern South America. The impact of land use and orography update in the model was analyzed to identify potential vulnerable natural areas by quantifying atmospheric deposition pollutants. CTMs allow simulating the physical dynamics of trace gasses and aerosols, including [...]