30 Jul 2020

PUBLICATION NOTICE: Environmental Analysis of Aqueous 3-Nitro-1,2,4-Triazol-5-One (NTO) by Ion Chromatography with Conductivity Detection

Abstract:  The newly fielded insensitive high-explosive compound 3-nitro-1,2,4-triazol-5-one (NTO) is mobile in the environment due to its high water solubility and low affinity for soils. The weak acidity of NTO (pKa 3.67) presents a challenge to environmental analysis by high-performance liquid chromatography but enables direct separation by ion chromatography (IC). Here we developed an IC method for NTO in natural water, soil, and postdetonation residue. A gradient potassium hydroxide separation effectively resolved the inorganic anions (F−, Cl−, NO2−, Br−, SO42−, NO3−, and PO43−) and NTO in 18 minutes. Suppressed conductivity of aqueous NTO was linear from 10 µg/L to 10 mg/L with a detection limit of 3 µg/L and quantitation limit of 9 µg/L. Recoveries of NTO-spiked natural water samples were 93%–118% at concentrations of 30, 100, and 500 µg/L. Recoveries of NTO-spiked soil samples were 91%–114% using deionized water (DI) extraction. NTO was completely recovered with DI-extraction in two postdetonation residue samples of IMX-101 but only partially recovered (58% and 69%) in two higher-concentration residues, potentially due to incomplete dissolution of the energetic particle matrix. These results support IC for confirmation analysis of environmental samples and for screening natural water samples while simultaneously analyzing inorganic ions.

30 Jul 2020

PUBLICATION NOTICE: A Comparison of Frost Depth Estimates from Ground Observations and Modelling Using Measured Values and Reanalysis Data for Vehicle Mobility 

Abstract: Frozen soils can withstand heavy vehicle loads and provide major maneuver corridors in locations where the soils are otherwise too weak to support the loading conditions. Vehicle mobility models require input of the ground conditions to assess seasonal traffickability. Increasingly, measured air temperatures from weather station locations are becoming more widespread, however they lack a global gridded coverage. Similarly, ground profile measurements, such as soil temperature and moisture, are significant inputs to estimate depths of frost. New data products, such as gridded reanalysis data provides weather and soil data on a gridded global scale. This study compared frost depths determined from measured soil temperatures at stations in North Dakota and Minnesota with frost depths determined from soil temperatures from NASA’s Modern Era Retrospective Analysis for Research Application Version 2 (MERRA-2). The objectives of the study were to evaluate the usefulness of the MERRA-2 data to provide estimates of frost depth, and to determine the accuracy of estimated frost depths from modelling using either measured air temperatures or reanalysis air temperature data. To estimate the maximum frost depth a one-dimensional decoupled heat and moisture flow model was used. Differences in estimated frost depth resulted from modelling when compared to the measured soil temperatures. These differences are likely due to the influence of a snow layer. The properties of the snow layer play an important role in estimating the depth of frost. Improved material properties of the snow layer are needed to more accurately estimate the depth of ground freezing.

9 Jul 2020

PUBLICATION NOTICE: Spatiotemporally coherent tensor decompositions for the analysis of trajectory data By Trevor Ruiz and Charlotte Ellison

Abstract: Location acquisition technologies such as global positioning systems (GPS) sensors or telemetry devices generate abundant spatiotemporal measurements of movement of people, animals, and vehicles. The resultant data represent trajectories-paths in space and time traversed by moving objects- and can often be merged with additional information about the entities in motion from connected or external data sources (Zheng 2015). New data analysis frameworks may be able to uncover patterns of human behavior from the fused trajectory and contextual i information. This data and new insights gained from novel analysis tools are p potentially of great interest to the Army and the geospatial community.

9 Jul 2020

PUBLICATION NOTICE: Influences of U Sources and Forms on Its Bioaccumulation in Indian Mustard and Sunflower

Abstract: Anthropogenic activities, such as ore mining and processing, nuclear power generation, and weapon tests, have generated uranium (U) contamination to soils and waters. The mobility and bioavailability of U are influenced by its sources, speciation, and plant species. Phytoremediation has emerged as an environmentally friendly, cost-effective green technology to remediate radioisotope-and metalcontaminated soils. The main objective of this study was to explore the feasibility using sunflower (Helianthus annuus) and Indian mustard (Brassica juncea) in cleaning up soils with UO2, UO3, and UO2(NO3)2. Uranium was found to be bioaccumulated in plant roots more than plant shoots. Uranium uptake by both plant species was significantly higher from the UO3- and uranyl-contaminated soils than from UO2- contaminated soils. UO3- and UO2(NO3)2-contaminated soils showed higher exchangeable, weak acid extractable, and labile U than the UO2-contaminated soils. After a growing season, three U forms decreased as redistribution/transformation of U resulted in U species with lower extractability. This study indicates the importance of U speciation in soil with regard to the potential use of sunflower and Indian mustard for phytoremediation of U-contaminated soils.

9 Jul 2020

PUBLICATION NOTICE: Foundations of Mission Analysis Storytelling (FOMAS)

Abstract: Mission analysis is a critical step in military planning and decision-making. It is currently time-consuming for analysts, who have few automated tools. The Foundations of Mission Analysis Storytelling (FOMAS) project developed algorithms, tools, and methods to automate sensemaking for mission analysis, which reduces the time and increases the effectiveness of the process. This report describes the FOMAS research, specifically as it relates to storytelling and link analysis. It includes descriptions of storytelling and a related prototype implementation, “Spatio-temporal Retrieval and Introspection of Data and Embedded Relationships, (STRIDER).” It also describes user engagements involving STRIDER and a prototype information collection and processing tool, the Big Open Source Social Science (BOSSS).

9 Jul 2020

PUBLICATION NOTICE: Hydrodynamics of a Recently Restored Coastal Wetland: Hamilton Wetlands, California

Abstract: Hamilton Wetlands is a recently restored tidally influenced basin located along the northwest coast of San Pablo Bay, California. Instruments to measure waves, currents, and wind were deployed for a period of up to 2 years shortly after tidal flow was re-introduced to the wetland to examine the sediment and hydrodynamic response. The results indicate that local re-suspension is relatively rare owing to the weak interior tidal currents and the limited fetch within the 3 km long basin. Asymmetries in the acoustic backscatter intensity combined with the much higher flow speeds measured at the entrance suggest a net import of fine sediment. The basin also experiences a distinct seasonal variation that likely contributes to sediment re-distribution. During the summer months, higher wind speeds correlate with turbidity suggesting local re-suspension of fines that are distributed by winds. Overall, the measurements suggest that the sediment dynamics in this shallow water system are controlled by two main factors: (1) net sediment import through the inlet entrance and (2) mixing of interior sediment through a combination of intermittent wind and wave stirring.

9 Jul 2020

PUBLICATION NOTICE: Rapid Tidal Reconstruction for the Coastal Hazards System and StormSim Part I: Coastal Texas and Louisiana

Abstract: incorporating a rapid tidal time series reconstruction and prediction subroutine within the Coastal Hazards System (CHS) framework. The CHS (https://chs.erdc.dren.mil) is a national database and web tool that provides probabilistic coastal hazard analysis (PCHA) products developed from regional studies such as the North Atlantic Coast Comprehensive Study (Nadal-Caraballo et al. 2015; Cialone et al. 2015). PCHA considers hazards due to both tropical and extratropical cyclones, depending on the storm climatology of the region of interest. The CHS supports feasibility studies, probabilistic design of coastal structures, flood risk management for coastal communities, and critical infrastructure. In the case of tropical cyclones (TCs) or hurricanes, both the timing of landfall and the level of the astronomical tide at the landfall location are critical in determining the magnitude of the still water level (i.e., storm surge + wave setup + astronomical tide). Therefore, a robust and accurate tide prediction methodology is needed to provide reliable reconstruction of tidal time series for historical, synthetic, and forecasted hurricane scenarios. This CHETN also discusses the quantification and validation of the Advanced Circulation (ADCIRC) tidal constituent database in the coastal Texas and Louisiana region as well as the implementation of the tidal reconstruction program Unified Tidal analysis (UTide) in the CHS framework.

1 Jul 2020

PUBLICATION NOTICE: Laboratory spiking process of soil with various uranium and other heavy metals

Abstract: Laboratory studies using metal spiked soils are challenging due to soil heterogeneity. This work provides an easy, quick, precise, and accurate technique for the preparation of spiked soils for laboratory research. The process described spiking soil with various uranium species and other heavy metals for laboratory scale pilot experiments under various biogeochemical conditions. The procedure involves grinding both dry soil and metal chemicals into the fine powder. The spiked soil mixture was further homogenized through a modified splitting and combining of the sample by diagonal flipping using plastic sheeting. Comparison of measured concentrations with theoretical values were obtained with <20% precision and accuracy. However, tradition spiking method with metal solution of-ten yielded high heterogeneous spiked soils due to strong metal adsorption in soils. Re-drying and re-grinding of soils were required following the spiking in order to homogenize treated soils, generating inhalable particulates. Thus appropriate personal protective equipment and practices are required for the safety concern. The present method with metal salt powder proved a safe, useful, quick, accurate and precise, and homogenized soil spiking method.

1 Jul 2020

PUBLICATION NOTICE: Spatial Analysis of Precipitation and Snow Water Equivalent Extremes for the Columbia River Basin

Abstract: Recent advances in the spatial statistics of extremes and model calibration were applied to develop and deliver areal-exceedance estimates for precipitation (PREC), by season and duration, and snow water equivalent (SWE), by cool season month and for the water year, for 758 delineated sub-basins of the Columbia River Basin (CRB), which correspond to a new CRB hydrology model watershed delineation. Understanding that future US Army Corps of Engineers, Northwestern Division, mission requirements may change, project execution also included the development and delivery of an application guidance document to credibly compute areal-exceedance estimates, including uncertainty, for PREC or SWE for any arbitrary area within the CRB. R, a free software environment for statistical computing and graphics (https://www.r-project.org/), and QGIS, a free and open source geographic information system (https://qgis.org/en/site/index.html), were the primary tools used for product development and delivery. The following R software packages were primarily used during project execution: evd, Glmnet, maps, raster, rgdal, SDMTools, sp, and SpatialExtremes.

1 Jul 2020

PUBLICATION NOTICE: Laboratory Simulation of Uranium Metal Corrosion in Different Soil Moisture Regimes

Abstract: A novel laboratory simulation system has been developed for the study of the corrosion of uranium metal in soils. Corrosion and transportation of depleted uranium (DU) as the metal undergoes weathering as a buried material within the soil environment. The corrosion of uranium metal in soil was not well understood due to the gas-liquid-solid phase of the soil. This study presents a novel method to investigate the change of uranium species during the process of process of oxidation of metallic uranium in these environments. Compared with other techniques used for the study of environmental corrosion of metals in soils, this method has the ad-vantage of low secondary uranium pollution, no energy consumption, and ease of operation. The simulation system has been used for the following studies: • Simultaneously simulate the corrosion of uranium metal in different soil moisture regimes • Study the influence of biogeochemical factors on the corrosion of uranium metal • Investigate the change of uranium species during oxidation.