18 Apr 2024

Standardized NEON Organismal Data for Biodiversity Research

Abstract: Understanding patterns and drivers of species distribution and abundance, and thus biodiversity, is a core goal of ecology. Despite advances in recent decades, research into these patterns and processes is limited by a lack of standardized, high-quality, empirical data spanning large spatial scales and long time periods. The NEON fills this gap by providing freely available observational data generated during robust and consistent organismal sampling of several sentinel taxonomic groups within 81 sites distributed across the US and will be collected for at least 30 years. The breadth and scope of these data provide a unique resource for advancing biodiversity research. To maximize the potential of this opportunity, however, it is critical that NEON data be accessible and easily integrated into investigators’ workflows and analyses. To facilitate its use for biodiversity research and synthesis, we created a workflow to process and format NEON organismal data into the ecocomDP (ecological community data design pattern) format available through the ecocomDP R package; provided the standardized data as an R data package (neonDivData). We briefly summarize sampling designs and data wrangling decisions for the major taxonomic groups included. Our workflows are open-source so the biodiversity community may: add additional taxonomic groups; modify the workflow to produce datasets appropriate for their own analytical needs; and regularly update the data packages as more observations become available. Finally, we provide two simple examples of how the standardized data may be used for biodiversity research. By providing a standardized data package, we hope to enhance the utility of NEON organismal data in advancing biodiversity research and encourage the use of the harmonized ecocomDP data design pattern for community ecology data from other ecological observatory networks.

21 Mar 2024

Autonomous Vehicle Testing: A Survey of Commercial Test Sites and Features

Abstract: Connected and autonomous technologies are valuable to the Army because of their recognized potential to reduce the number of personnel exposed to threats in forward operations. The successful integration of such technologies has the potential to reduce Soldier deaths and injuries. Automation of routine tasks can also allow warfighters to focus their time on more strategic efforts. Furthermore, a reduction in manpower is expected to proportionally reduce energy use and material supply and resupply demands while bolstering resilience. To achieve these benefits, the reliability, safety, and utility of connected and autonomous systems must be successfully demonstrated in a variety of conditions before widespread adoption. Therefore, the Army needs a realistic testing environment to develop, test, and evaluate emerging technologies. This environment and its supporting infrastructure should provide a variety of terrain, functional areas, and power scenarios and should be able to demonstrate the viability of connected and autonomous technologies on an operational scale. The primary objective of this research was to survey US commercial facilities associated with autonomous vehicle development, testing, and evaluation.

20 Mar 2024

Hazardous and Solid Waste Management Planning in Select African Countries

Abstract: Managing wastes produced during contingency operations in United States Africa Command (USAFRICOM) locations has historically relied on local contract disposal or open-air burn pits, which have been shown to be harmful to the health of service members. Posture locations that can find alternative ways to manage waste, specifically through contracts with the host country’s waste services, can better protect the health and safety of the warfighter and the native landscapes. African waste systems are complex, decentralized systems with considerable regional variation. The lack of government-funded waste management services leaves many residents with few options for safe disposal. The differing waste disposal strategies are described to offer guidance for military operations in the focus countries of Gabon, Ghana, Kenya, Morocco, Niger, Senegal, and Uganda. Relevant international agreements regulating the flow of hazardous waste across borders that can impact disposal plans are also noted. This report serves as a reference to develop waste management alternatives in the USAFRICOM area of responsibility (AOR). Official Department of Defense and Army regulations should be consulted when devising an integrated waste management plan.

5 Mar 2024

Environmental DNA Sampling for At-Risk and Invasive Species Management on Military Ranges: Guidelines and Protocols for Installation Biologists and Land Managers

Abstract: Environmental DNA (eDNA) analysis, or the detection of trace DNA shed by organisms into their environment, has the potential to transform Army capabilities for threatened and endangered species (TES) and invasive species management by providing a rapid, noninvasive, and cost-effective option for monitoring wildlife. Despite these benefits, eDNA analysis is underutilized on military installations as limited access to guidance materials, protocols, training opportunities, and support from eDNA scientists makes it difficult for installation biologists and military land managers to design and execute eDNA surveys, let alone identify management questions that may benefit from eDNA monitoring. Therefore, the aim of this resource is to increase awareness of the benefits and limitations of eDNA monitoring and provide eDNA study design guidelines and field sampling protocols for nonexperts to make this tool more accessible to installation biologists and land managers and help facilitate the adoption of eDNA-based approaches for wildlife management on military ranges.

28 Feb 2024

Characterising Earth Scent

Abstract: Rationale. Earth scent is the odour emitted from soils. This scent, primarily comprising the alcohols geosmin and 2-methylisoborneol (MIB), has not been fully characterised, but offers high potential for use as an environmental interrogation tool. Methodology. We utilised our field- based, solid-phase microextraction fibre method to test the hypothesis that soil activity and soil property variation can be detected in situ by comparing biogenic volatile emissions. Results. We eliminated sources of error utilising field-based sampling with these fibres, concluding that room temperature storage for up to 7 days is acceptable with minimal loss. Variation in individual fibre affinity for both compounds was higher than expected but no measured concentrations were observed to constitute outliers. Disturbance of minor soil volumes led to significantly higher emission of both compounds over background levels. Soil texture and soil cover had a significant effect on the emission of both compounds. Simulated rainfall, producing the characteristic odour known as petrichor, initiates elevated emission of geosmin. Background (undisturbed soil) concentrations of MIB were occasionally detectable during some sampling events, but geosmin concentrations in the air were always below detection limits without soil disturbance. Virtually all background and disturbed soil samples contained much higher concentrations of MIB compared to geosmin, but geosmin variation between replicates and experimental units was much lower. Discussion. Soil disturbance and soil property variation can be remotely detected using emission of volatile compounds. Correlating emission from the soil with respect to disturbance events and environmental properties could yield a powerful new tool for acquiring soil information.

2 Feb 2024

The Influence of Mesoscale Atmospheric Convection on Local Infrasound Propagation

Abstract: Infrasound—that is, acoustic waves with frequencies below the threshold of human hearing—has historically been used to detect and locate distant explosive events over global ranges (≥1,000 km). Simulations over these ranges have traditionally relied on large-scale, synoptic meteorological information. However, infrasound propagation over shorter, local ranges (0–100 km) may be affected by smaller, mesoscale meteorological features. To identify the effects of these mesoscale meteorological features on local infrasound propagation, simulations were conducted using the Weather Research and Forecasting (WRF) meteorological model to approximate the meteorological conditions associated with a series of historical, small-scale explosive test events that occurred at the Big Black Test Site in Bovina, Mississippi. These meteorological conditions were then incorporated into a full-wave acoustic model to generate meteorology-informed predictions of infrasound propagation. A series of WRF simulations was conducted with varying degrees of horizontal resolution—1, 3, and 15 km—to investigate the spatial sensitivity of these infrasound predictions. The results illustrate that convective precipitation events demonstrate potentially observable effects on local infrasound propagation due to strong, heterogeneous gradients in temperature and wind associated with the convective events themselves. Therefore, to accurately predict infrasound propagation on local scales, it may be necessary to use convection-permitting meteorological models with a horizontal resolution ≤4 km at locations and times that support mesoscale convective activity.

23 Jan 2024

Historic Context for the WWII Internment and Prisoner-of-War (POW) Compound at Fort McCoy, Wisconsin

Abstract: This report provides a comprehensive historic context for the enemy alien internment compound and prisoner-of-war (POW) compound at Fort McCoy, Wisconsin, during World War II (WWII). Through primary and secondary sources, it illustrates the development of the internment and POW program at the installation, the built environment, labor details, and aspects of daily life. Although buildings associated with the internment and POW compound are no longer extant, researchers georeferenced historic maps of the compound to create digital footprints of the demolished infrastructure. Additionally, researchers generated and analyzed lidar returns to accentuate the signatures of former building foundations. Together, these processes can help fieldwork investigators determine the approximate locations of former internment and POW infrastructure.

12 Jan 2024

An Elastic-Inelastic Model and Embedded Bounce-Back Control for Layered Printing with Cementitious Materials

Abstract: This paper presents a finite-deformation model for extrusion-based layered printing with cementitious materials. The evolution of mechanical properties as the printed material cures and stiffens results in nonphysical reduction in the magnitude of elastic strains when standard constitutive models are employed. This elastic recovery of the printing induced deformation contradicts the experimentally observed behavior of the printed cementitious materials that harden at a nearly-frozen deformed state. A thermodynamically motivated constraint on the evolution of elastic strains is imposed on the constitutive model to remedy the nonphysical bounce-back effect. An algorithm that is based on a strain-projection technique for the elastic part of deformation is developed that complements the inelastic response given by the Drucker–Prager model. It is then embedded in a finite strain finite element framework for the modeling and simulation of cure hardening and inelastic response of the early age cementitious materials. A ghost mesh method is proposed for continuous layer-wise printing of the material without the need for intermittent mesh generation technique or adaptive remeshing methods. The model is validated via comparison with experimental data and representative test cases are presented that investigate the mathematical and computational attributes of the proposed model.

12 Jan 2024

Levees and Dams at Fort Riley, Kansas, and the Response to the 1951 Flood

Abstract: This project provides a historic context and inventory for the levees and dams constructed at Fort Riley, Kansas. The purpose of this historic con-text and inventory is to determine the levees and dams’ eligibility for listing in the National Register of Historic Places (NRHP). Determinations of eligibility to the NRHP are then made based on the significance of the levees and dams and the degree to which they retain their integrity for conveying that significance. The authors inventoried and evaluated three levees and two lake dams on the installation. Based on the historic context and inventory, researchers for this project have determined that none of the levees and dams are eligible for the inclusion in the NRHP nor was there enough evidence for a noncontiguous historic district at Fort Riley.

11 Jan 2024

Simulated Barge Impacts on Fiber-Reinforced Polymers (FRP) Composite Sandwich Panels: Dynamic Finite Element Analysis (FEA) to Develop Force Time Histories to Be Used on Experimental Testing

Abstract: The purpose of this study is to evaluate the dynamic response of fiber-reinforced polymer (FRP) composite sandwich panels subjected to typical barge impact masses and velocities to develop force time histories that can be used in controlled experimental testing. Dynamic analyses were performed on FRP composite sandwich panels using the finite element method software Abaqus/Explicit. The “traction-separation” law in the Abaqus software is used to define the cohesive surface interaction properties to evaluate the damage between FRP composite laminate layers as well as the core separation within the sandwich panels. Numerical models were developed to better under-stand the damage caused by barge impacts and the effects of impacts on the dynamic response of composite structures. Force, displacement, and velocity time histories were obtained with finite element modeling for several mass and velocity cases to develop experimental testing procedures for these types of structures.