11 Jul 2024

Composite Material Applications and Research Roadmap for US Army Corps of Engineers Civil Works

Abstract: This report discusses and ranks the remaining research, development, and deployment opportunities for fiber-reinforced polymer composite materials in USACE marine infrastructure applications. Following the successes of at least 10 fiber-reinforced polymer composite pilot projects from 2015 to 2022, Public Law 117-58, the Infrastructure Investment and Jobs Act, allocated funding for a roadmap report that articulates lingering implementation barriers and prioritizes steps to overcome those challenges through laboratory and field experimentation. The objective analysis herein draws from real Operational Condition Assessment data generated in the field. Key opportunities lie in inspection techniques, standardized design approaches for molded components, and improved guidance to ad-dress abrasion, fatigue, and concentrated load cases at the 10-meter scale.

10 Jul 2024

Historic Landscape Inventory for Zachary Taylor National Cemetery, Louisville, Kentucky

Abstract: This project was undertaken to provide the US Department of Veterans Affairs, National Cemetery Administration, with a cultural landscape inventory of Zachary Taylor National Cemetery via funding from the St Louis Mandatory Center of Expertise (MCX) for the Curation and Management of Archaeological Collections (CMAC). The 16-acre cemetery, listed on the National Register of Historic Places in 1983, is found in Louisville, Kentucky, and contains more than 11,400 burials. The US Army Engineer Research and Development Center-Construction Engineering Research Laboratory (ERDC-CERL) was tasked with inventorying and assessing the cultural landscape at Zachary Taylor National Cemetery through the creation of a landscape development context, a description of current conditions, and an analysis of changes to the cultural landscape over time. All landscape features were included in the survey as federal policy on national cemeteries requires that all national cemetery landscape features be considered contributing elements, regardless of age. The historic landscape elements of the cemetery, like the original overarching Beaux-Arts plan and circulation, cannot be restored due to the current number of burials. However, some elements can be reemphasized by historic landscape management planning, such as the restoration of the portions of the allée of pin oak (Quercus palustris) trees.

10 Jul 2024

Historic Landscape Inventory for Mare Island Naval Cemetery, California

Abstract: This project was undertaken to provide the US Department of Veterans Affairs (VA), National Cemetery Administration (NCA), with a cultural land-scape inventory of Mare Island Naval Cemetery. The approximately 2.5-acre cemetery is located in Vallejo, California, and contains more than 900 burials. Mare Island Naval Cemetery is part of the Mare Island Naval Shipyard historic district, which was listed concurrently on the National Register of Historic Places and as a National Historic Landmark in 1975. The NCA tasked the US Army Engineer Research and Development Center-Construction Engineering Research Laboratory (ERDC-CERL) with inventorying and assessing the cultural landscape at Mare Island Naval Cemetery through the creation of a landscape development context, a description of current conditions, and an analysis of changes to the cultural landscape over time. All landscape features were included in the inventory as NCA requested ERDC-CERL to follow federal policy on national cemeteries that requires that all national cemetery landscape features be considered contributing elements, regardless of age.

31 May 2024

pH Pivoting for Algae Coagulation: Bench-Scale Experimentation

Abstract: Harmful algal blooms (HABs) threaten recreational waters and public supplies across the US, causing detrimental economic and environmental effects to communities. HABs can be mitigated with dissolved air flotation (DAF) treatment, which requires addition of pH-sensitive charged chemicals to neutralize algae, allowing them to attach to microbubbles and float to the surface. During HAB events and photosynthesis, algae raise the pH to levels that are not ideal for DAF. Traditionally, pH is reduced with a strong acid; however, this adds operational cost and permanently adjusts the water’s pH. This study assessed an approach that might allow for infusing CO₂ from diesel-powered electricity generators into the water prior to DAF treatment. It was hypothesized that formation of carbonic acid could temporarily reduce the pH. Results showed that 2.5%–5.0% CO₂ mixed within compressed air can achieve pH levels between 6–7 in algal water with an initial pH of 9–11 and alkalinity of 150 mg/L as CaCO₃. Further, dosing CO₂ before chemical addition yielded a 31% improvement in water clarification. Returning the pH back to natural levels was not achieved using ambient air microbubbles; however, coarse bubble air spargers should be tested to provide more volumetric capacity for CO₂ absorption.

7 May 2024

Spherical Shock Waveform Reconstruction by Heterodyne Interferometry

Abstract: The indirect measurement of shock waveforms by acousto-optic sensing requires a method to reconstruct the field from the projected data. Under the assumption of spherical symmetry, one approach is to reconstruct the field by the Abel inversion integral transform. When the acousto-optic sensing modality measures the change in optical phase difference time derivative, as for a heterodyne Mach–Zehnder interferometer, e.g., a laser Doppler vibrometer, the reconstructed field is the fluctuating refractive index time derivative. A technique is derived that reconstructs the fluctuating index directly by assuming plane wave propagation local to a probe beam. With synthetic data, this approach is compared to the Abel inversion integral transform and then applied to experimental data of laser-induced shockwaves. Time waveforms are reconstructed with greater accuracy except for the tail of the waveform that maps spatially to positions near a virtual origin. Furthermore, direct reconstruction of the fluctuating index field eliminates the required time integration and results in more accurate shock waveform peak values, rise times, and positive phase duration.

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.