27 Sep 2024

Potential Engineering With Nature Features to be Incorporated at Woodtick Peninsula

Purpose: Woodtick Peninsula is a barrier peninsula in western Lake Erie where restoration activities are being planned to combat erosion of the peninsula wetlands through placement of dredged material. As part of the restoration effort, design of an artificial reef is currently underway to function as a breakwater, preventing erosion of the fine-grained material being hydraulically placed along the west side of the peninsula. To the extent possible, it is desirable to design the reef such that it would not only provide erosion protection, but also incorporate features that would provide habitat, and thereby support the goals of Engineering With Nature® (EWN®). EWN is a concept focused on aligning natural and engineering processes to deliver economic, environmental, and social benefits efficiently and sustainably through collaboration. A range of breakwater and shoreline armoring alternatives have been utilized in coastal environments to enhance habitat. While a number of alternatives have been successfully demonstrated in marine waters, fewer structures have been adapted to freshwater systems of the Great Lakes. However, there have been several demonstrations within the Great Lakes in which breakwater structures have been enhanced to incorporate habitat features. In this report, potential designs for breakwaters and shoreline edging in freshwater systems that can incorporate EWN benefits are summarized.

27 Sep 2024

Beneficial Use of Dredged Sediment in South St. Paul, Minnesota: 100 Years of Economic, Social, and Environmental Innovation

Purpose: This technical note provides a review of beneficial use (BU) of dredged sediment in a 5-mile river reach of the Upper Mississippi River System (UMRS) that demonstrates the triple-win solutions championed by the US Army Corps of Engineers (USACE) Engineering With Nature® Program. Several case studies exemplifying the BU of dredged sediment are presented along with a more in-depth review of the Pigs Eye Lake Islands ecosystem restoration project.

27 Sep 2024

Surveys in Native and Introduced Ranges (2018–2021) for Natural Enemies of Yellow Floating Heart, Nymphoides peltata Kunth

Abstract: Yellow floating heart (Nymphoides peltata), a widespread aquatic invasive plant in the US, is currently under investigation for biological control de-velopment. From 2018 to 2021, we conducted native (Europe: 14 loca-tions; Asia: 80 locations) and introduced (US: 39 locations) range surveys to create a list of candidate agents and collect baseline infestation data for comparison. We genetically characterized populations and determined those most-closely related to US N. peltata were European. However, we found no promising agents in that region, except for previously reported fungal pathogens. In Asia, several herbivores were identified as potential agents based on observed damage in situ and previous literature reports about host specificity. These included three species of Bagous weevils, one of which may be Bagous charbenensi, and an unidentified leaf-mining Hy-drellia fly. During domestic surveys, generalist leaf-cutting caterpillars were common, similar to the native range. A major discovery was the dam-aging fungal pathogen, Septoria villarsiae, isolated from plants in a pri-vate pond in Maine—the first record in the Western hemisphere. The next steps for this program should include preliminary host specificity and im-pact assessments of S. villarsiae, the fruit-feeding Bagous spp. in China and Korea, and the leaf-mining Hydrellia sp. fly from South Korea.

26 Sep 2024

A Geospatial Model for Identifying Stream Infrastructure Locations

Abstract: Management of hydraulic infrastructure for flood control, hydropower, navigation, and water supply is a critical component of the Army Dams and Transportation Infrastructure Program (ADTIP). This project provides a tool to locate stream infrastructure using a one-dimensional approach supplemented with geospatial filtering that only needs digital elevation model (DEM) files as primary input. The regions in and around Forts Liberty, Sill, and Cavazos were selected as study areas, and stream networks with corresponding stream elevation profiles were created and searched for elevation changes that met vertical threshold and search window criteria. Recall, Fβ, and a ratio of under to overprediction were used to evaluate performance. The search algorithm generally overpredicts the number of stream infrastructure locations and especially so for large search windows (20 or 25 cells) and small vertical threshold values (5 or 10 m). Overall, it was found that midrange vertical threshold values (2 or 2.5 m with long search windows (20 or 25 cells) with the land cover classification (LCC) check applied yielded results that minimized false negatives and overpredictions. The significance of this tool is that it may reduce costly field investigations, or at least aid in the prioritization of site visits for hydraulic infrastructure managers.

26 Sep 2024

High-Rate Characterization and Modeling of a Hyperelastic Block Copolymer Subjected to Ballistic Impact

Abstract: A polystyrene-polyisobutylene-polystyrene star-block copolymer (PS-PIB-PS) is a thermoplastic elastomer with visco hyperelastic characteristics that displays a high level of toughness and performs well in shock attenuating applications. The research goal is to investigate experimentally and numerically the capacity of PS-PIB-PS to dissipate kinetic energy and examine its deformation and failure modes under impact by spherical steel projectiles at speed ranges of 200–1,700 m/s. First, PS-PIB-PS is characterized using a Split-Hopkinson Pressure Bar to measure high strain rate response and calibrate a hyperelastic material model. Second, ballistics tests are conducted on 12 in. × 12 in. PS-PIB-PS targets with various thicknesses to determine the ballistic limit and residual velocity (Vr) versus impact velocity (Vi) relationship. Finally, ALE3D is used to model the ballistic response and capture the extreme deformation observed during testing. During ballistic impact tests, significant deformation occurred on the backside of polymer targets, followed by perforation of the polymer, culminating with retraction and recovery of the polymer in a self-healing manner. Numerical simulations captured the deformation behavior during impact and predicted the Vr versus Vi response with high accuracy. This research provides a method of modeling hyperelastic materials subjected to ballistic impact and provides a better understanding of energy dissipation of these materials.

25 Sep 2024

Comparing the Thermal Infrared Signatures of Shallow Buried Objects and Disturbed Soil

Abstract: The alteration of physical and thermal properties of native soil during object burial produces a signature that can be detected using thermal infrared (IR) imagery. This study explores the thermal signature of disturbed soil compared to buried objects of different compositions (e.g., metal and plastic) buried 5 cm below ground surface (bgs) to better understand the mechanisms by which soil disturbance can impact the performance of aided target detection and recognition (AiTD/R). IR imagery recorded every five minutes were coupled with meteorological data recorded on 15-minute intervals from 1 July to 31 October 2022 to compare the diurnal and long-term fluctuations in raw radiance within a 25 × 25 pixel area of interest (AOI) above each target. This study examined the diurnal pattern of the thermal signature under several varying environmental conditions. Results showed that surface effects from soil disturbance increased the raw radiance of the AOI, strengthening the contrast between the object and background soil for several weeks after object burial. Enhancement of the thermal signature may lead to expanded windows of object visibility. Target age was identified as an important element in the development of training data sets for machine learning (ML) classification algorithms.

25 Sep 2024

Thermography Conversion for Optimal Noise Reduction

Abstract: Computer vision applications in terms of raw thermal radiance are limited by byte size. Normalizing the raw imagery reduces functional complexities that could otherwise aide a computer processing algorithm. This work explores a method to normalize 16-bit signed integer (I16) into unsigned 8-bit (U8) while maintaining the integrity of the correlation coefficients between the raw data sets and the environmental parameters that affects thermal anomaly detectability.

25 Sep 2024

Accelerated Concrete Flexural Strengths for Airfield Pavements

Abstract: Mixture-proportioning studies and submittals are an integral part of the pavement design and planning process as outlined in the Unified Facilities Guide Specification 32 13 14.13 for Department of Defense airfield pavements. Many aspects of the required testing are time-consuming due to the duration of the test (e.g., alkali–silica reaction experiments) or to the required concrete age at testing (e.g., compressive or flexural strength testing). Time awaiting testing results often delays projects and adds cost. The objective was to develop an accelerated testing requirement for flexural strength (currently 650 psi or greater at 90 days), thereby reducing the time to pavement acceptance. Potential accelerated testing methodologies were evaluated in a literature review. A statistical analysis generated under a design of experiments protocol determined concrete flexural strength gain and correlation ratios. Results of the statistical analysis showed that a reduced flexural strength of 600 psi could be accepted at 14 days and still reach the minimum flexural strength requirement of 650 psi at 90 days with high certainty (i.e., greater than 95% certainty). Additionally, the results stemming from the design of experiments compared favorably with data gathered from four mixture-proportioning submittals acquired via the Transportation Systems Center.

24 Sep 2024

Validation of Sample Extraction and Analysis Techniques for Simultaneous Determination of Legacy and Insensitive Munitions (IM) Constituents

Abstract: Currently, no standardized method exists for the analysis of insensitive munitions (IM) in environmental matrices such as water, soils, and tis-sues. However, standardized methods, such as United States Environmental Protection Agency (EPA) 8330B, exist for legacy munitions for water and soil matrices. The lack of standardized methods for IM analysis leads researchers to use a wide variety of incomplete and overlapping analytical methodologies. The overall project’s first phase, Strategic Environmental Research and Development Program (SERDP) Environmental Restoration (ER)–2722, was to develop and optimize methods to address these methodological gaps by creating analytical methods for simultaneous analysis of IM and legacy munitions in water, soil, and tissue matrices. The main objective of the current project phase, Environmental Security Technology Certification Program (ESTCP) ER19-5078, is to build upon the previous work in phase one and to focus on the validation of the newly developed methods. Synergizing with the main objective of the overall project, the methods were validated and submitted to the EPA for inclusion as a possible addendum to EPA 8330B.

19 Sep 2024

The Forefront: A Review of ERDC Publications, Summer 2024

Abstract: As the main research and development organization for the US Army Corps of Engineers (USACE), the Engineer Research and Development Center (ERDC) helps solve our nation’s most challenging problems. With seven laboratories under the ERDC umbrella, ERDC expertise spans a wide range of disciplines. This issue of the Forefront highlights several ERDC reports from FY22, many of which were highly recognized and widely downloaded. The Forefront team was honored in FY23 to receive both the Information Technology Laboratory’s Communication Award and the ERDC Communication Award for our Summer 2022 issue of the Forefront. The Forefront team and the Information Science and Knowledge Management Branch (ISKM) as a whole are committed to staying current with best practices and exploring new techniques to communicate ERDC’s research excellence. Through quality publications, dynamic presentations, and ongoing training opportunities, ISKM strives not only to support ERDC but also to blaze a path to clear, concise, and engaging scientific communication products. Remember, if it ever takes you more than five minutes to find an answer, contact us. We are here to help!