12 Aug 2025

Applying the Working with Nature Philosophy to Navigation Infrastructure Projects

Abstract: In 2008, the World Association for Waterborne Transport Infrastructure published a position paper describing a Working with Nature philosophy aimed to change how the sector approaches navigation and port infrastructure projects. In 2018, Pianc published guidance on implementing WwN. Pianc’s guidance presents a six-step process that encourages consideration of site-specific ecosystem characteristics and WwN opportunities at early stages of project development, early stakeholder engagement and integration of WwN into the development of project objectives before design begins. By incorporating WwN applications during conception, the WwN approach provides the most promising opportunities to affect positive outcomes for the environment. This holistic understanding of ecosystem processes and socioeconomic interactions realises environmental impacts can be minimised while concomitantly seeking opportunities to enhance ecosystem functions at various spatial and temporal scales. Project delivery thus goes beyond avoiding or compensating for negative project impacts and seeks multi-sector ecosystem and socioeconomic benefits. Applied in practice, WwN can increase habitat functionality, reduce energy associated with construction or maintenance, and enhance the short- and long-term delivery of ecosystem services. Projects consistent with the WwN philosophy achieve their underlying engineering objectives, alongside various co-benefits, consistent with the environmental, societal and economic sustainability pillars.

12 Aug 2025

Applicability of Two-Phase Modeling with Compression Experiments for Snow Compaction Dynamics

Abstract: Compaction is a rheological process which has been modeled using a 1-D two-phase continuum framework. However, it has been posed as a promising method for modeling densification of snow into glacial ice, where the conventional model is empirical or semi-empirical. We explored the applicability of a one-dimensional two-phase continuum framework for modeling snow compaction through theoretical and laboratory methods by analyzing and simplifying theory, then experimentally constraining the model coefficient. We found the limit of slow compaction is reached such that air evacuation during the compaction process does not impede the deformation of ice grains. Model-data comparisons are performed using data from a series of uniaxial compression experiments of snow samples under a range of compaction rates and densities at –10° and –20 °C. By defining a linear effective pressure function, we constrain the model parameter by tuning against the data. While our model follows proper simplification of theory, temperature and microstructural dependence are determined by the model parameter in a rheological formulation with the strain rate; much scatter still exists. Within the selected range of compaction rates and densities, a 1-D two-phase model with a continuum framework alone does not likely capture important processes involved in the compaction process.

12 Aug 2025

Carbon Nanotube-Based Segregated Thermoplastic Nanocomposites Structured via Electromagnetic Melt Processing

Abstract: The EM-processed TPNCs prepared with EM-susceptible carbon nanotubes exhibited a significant enhancement in transport and mechanical properties, outperforming conventionally processed TPNCs. Thus, EM-processed TPNCs demonstrated an ultralow electrical percolation threshold and a remarkable increase in volume electrical conductivity of 8 orders of magnitude at only 1.0 wt % CNT loading. This highlights the superior network formation, level of segregation, and structuring enabled by EM processing. Differential scanning calorimetry and X-ray diffraction revealed EM-processed TPNCs exhibited higher crystallinity and a predominantly α crystal phase compared to hot-pressed TPNCs. Microstructural inspection by electron microscopy disclosed EM processing led to segregated but interconnected multiscale networks of a thin and well-defined CNT interphase that encompassed from the nanoscale of CNTs to the macroscopic scale of TPNCs. The EM-processed TPNCs developed a statistically higher stiffness and in certain cases, even better strength than hot-pressed TPNCs. However, EM-processed TPNCs displayed significantly lower ductility, owing to their higher crystallinity, more brittle crystal α phase, and potential formation of microvoids in the bulk of the TPNCs inherent to the unoptimized EM processing. This work provides an understanding of an alternative and unconventional processing method capable of achieving higher structuring in nanocomposites with advanced multifunctional properties.

12 Aug 2025

Acoustic Winter Terrain Classification for Offroad Autonomous Vehicles

Abstract: Autonomous vehicles can experience extreme changes in performance when operating over winter surfaces, and require accurate classification to transit them safely. In this work we consider acoustic classification of winter terrain, and demonstrate that a simple and efficient frequency-space analysis exposed to a small convolutional neural network, rather than recurrent architectures or temporally-varying spectrogram inputs, is sufficient to provide near-perfect classification of deep snow, hardpacked surfaces and ice. Using a dual-microphone configuration, we also show that acoustic classification performance is due to a combination of vehicle noises and vehicle-terrain interaction noises, and that engine sounds can serve as a particularly powerful classification cue for offroad environments.

12 Aug 2025

Evaluating and Improving Snow in the National Water Model, Using Observations from the New York State Mesonet

Abstract: This study leverages observations from NYSM to evaluate and improve representation of snow within the NWM and its associated land surface model. Distributed NWM simulations were ran and analyzed, forced by gridded meteorological analyses, and Noah-MP point simulations, forced by NYSM observations. Distributed NWM runs, with a baseline configuration, show substantial SWE biases caused by biases in meteorological forcing used, imperfect representation of snow processes, and mismatches between land cover in the model and NYSM station locations. Noah-MP point simulations, using baseline configuration, reveal a systematic positive bias in SWE accumulation. Noah-MP point simulations, with improved precipitation phase partitioning, reveal a systematic negative bias in SWE ablation rates. Sensitivity experiments highlight uncertain parameters within Noah-MP that strongly affect ablation rates and show particularly large sensitivity to snow albedo decay time-scale parameter, which modulates snow albedo decay rates. Distributed NWM experiments, with precipitation phase partitioning and TAU0 adjusted based on Noah-MP point simulation results, show qualitatively similar sensitivities. However, the distributed experiments do not show clear improvements when compared to SWE and streamflow observations. This is likely due to some combination of sources of bias in the baseline-distributed run and biases in other parameterized processes unrelated to snow in the NWM.

11 Aug 2025

Cracking Performance Characterisation of Aramid Fiber-Reinforced Asphalt Mixtures Using Digital Image Correlation

Abstract: Conventional index-based testing of asphalt mixtures cannot accurately capture local deformation in a sample, limiting the usage of standard test measurements. The non-contact-based measurements proved effective to capture local deformation fields. This study aimed to capture the fatigue and thermal cracking behaviour of fiber-reinforced asphalt mixture by utilising digital image correlation (DIC). One binder (PG76-22), a diabase aggregate and three fibers (polyolefin/ aramid fibers (PFA) at 0.05% dosage and Sasobit-coated aramid fibers at 0.01% and 0.02% dosage) were used to prepare a total of four mixtures (one control and three FRAM). All these mixtures were produced at a local batch plant following manufacturer-recommended mixing methods. DIC analysis was performed for three-point bending beam (3PB) and disk shape compact tension (DCT) tests at intermediate temperature (25°C) and low temperatures of −12°C and −18°C. Based on index values from DCT and 3PB, the thermal and fatigue cracking performance enhancement was not significant. However, DIC analysis showed that, regardless of testing temperature, the crack propagated in a random pattern for FRAM, whereas the crack followed a relatively straight path for the control mix. Finally, based on DIC strain contours, FRAM mixtures exhibit distributed strain over a larger area compared to the control mix.

7 Aug 2025

C-Band Radar Measurements in a Snow-Covered Boreal Forest Environment

Abstract: Sled-based side-looking C-band radar profiles were collected around Fairbanks, Alaska, in March 2023 during the NASA SnowEx campaign to improve the conceptual understanding of C-band radar wave interactions with snow in a boreal forest environment. Seven transects with different vegetation and ground conditions were studied. Significant volume scattering from snow was observed in this shallow snowpack, indicating sensitivity at lower snow depths (SDs) which are common in high-latitude snowpacks. Manual removal of the snowpack decreased the backscatter by more than 2 dB in all polarizations, with a larger decrease in the cross-polarization, supporting the potential use of Sentinel-1 to retrieve SD.

7 Aug 2025

Financing Natural Infrastructure: Lightning Point, Alabama

Purpose: This technical note explores the restoration of Lightning Point, an award-winning natural infrastructure project led by The Nature Conservancy (TNC) in coastal Alabama. The story of Lightning Point provides an exemplar case study of successful coordination of cross-sector partnerships and the use of ecosystem services valuation to attract project funding.

7 Aug 2025

Continued Development of Methods for the Determination of Legacy and Insensitive Munitions from Environmental Matrices: Addition of Four Degradation Products and One Internal Standard to Previously Developed 29-Analyte Method

Abstract: To continue improving separation methods of explosive analytes and their degradation products, chromatographic methods from Environmental Protection Agency (EPA) 8330B, Strategic Environmental Research and Development Program (SERDP) 2722, and Environmental Sensors for Explosives were modified to include the separation of four additional analytes and one internal standard so that a total of 36 analytes could be resolved on a single column. Four degradation compounds, 3-amino-1,2,4-triazol-5-one (ATO); 1 methyl-3-nitroguandine (MeNQ); 2 methoxy-5-nitroaniline (MENA); and 4 methoxy-3-nitroaniline (iMENA) were added to the analytical method. The internal standard, 3,5-dinitrotoluene, was also added to the method to extend its application. Additionally, an analytical method on gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS) were explored for the analytes of interest.

7 Aug 2025

Thermodynamic Exposure Reductions of PCBs Available to Lumbriculus variegatus in Lake Erie Region Sediments Amended with Activated Carbon

Abstract: A chemical activity-based assessment of PCB bioaccumulation from Lake Erie region sediments was studied using polydimethylsiloxane coated fibers and Dow Corning silicone coated jars. Polymers equilibrated with the sediments were compared to bioaccumulation in blackworms, exposed to the sediments for 28 days. Sediments were from Cleveland Harbor, Ashtabula Harbor, and Buffalo River. Sediment from Ashtabula was amended with activated carbon. Using lipid-polymer partition coefficients, the polymers were able to estimate actual bioaccumulation in worms, with close to a 1:1 relationship and r2 = 0.94. If lipid normalized worm bioaccumulation was compared to equilibrated PDMS concentrations, there was a 20:1 ‘off-set,’ but the relation was still strong. Different doses of AC were mixed into Ashtabula sediment in the laboratory, corresponding to 1 %, 10 %, and 100 % of the native total organic carbon. Based on PCB concentrations in DC silicone, a target AC dose equal to 10 % of the TOC would substantially reduce bioaccumulation of the more hydrophobic PCBs from Ashtabula Harbor dredged material. Widespread AC amendment to surficial sediment of the eastern basin of Lake Erie may reduce the thermodynamic pressure of PCBs from that sediment source and allow for a continued decline in fish tissue concentrations.