26 Jun 2023

Antecedent Precipitation Tool (APT) Version 2.0: Technical and User Guide

Purpose: This document provides an overview of the technical components of the Antecedent Precipitation Tool (APT) and a user’s guide for the APT. The APT is an automation tool that the US Army Corps of Engineers (USACE) developed to facilitate the comparison of antecedent or recent precipitation conditions for a given location to the range of normal precipitation conditions that occurred during the preceding 30 yr*. In addition to providing a standardized methodology to evaluate normal precipitation conditions (precipitation normalcy), the APT queries additional datasets to assess the presence of drought conditions and the approximate dates of the wet and dry seasons for a given location. This document constitutes an update to Antecedent Precipitation Tool (APT) Version 1.0: Technical and User Guide (Gutenson and Deters 2022).

22 Jun 2023

US Air Force Academy Gallagher and Massey Ranch Houses: Historic American Buildings Surveys CO-237, CO-237-A, and CO-238

Abstract: The US Congress codified the National Historic Preservation Act of 1966 (NHPA), the nation’s most effective cultural resources legislation to date, mostly through establishing the National Register of Historic Places (NRHP). The NHPA requires federal agencies to address their cultural resources, which are defined as any prehistoric or historic district, site, building, structure, or object. Section 110 of the NHPA requires federal agencies to inventory and evaluate their cultural resources, and Section 106 requires them to determine the effect of federal undertakings on those potentially eligible for the NRHP. The US Air Force Academy is located at the base of the Front Range within El Paso County. The US Air Force Academy has been used for training US Air Force officers since 1954. The Gallagher Ranch House and its associated garage, erected circa 1953, and the Massey Ranch House, erected 1941, are eligible for the National Register of Historic Places. This report documents the buildings to the standards of the Historic American Buildings Survey and includes a historic context, architectural descriptions, photographs, and measured drawings. This report satisfies Sections 106 and 110 of the National Historic Preservation Act of 1966 as amended and will be used by the US Air Force Academy for mitigation, allowing for the demolition of the three buildings.

22 Jun 2023

Development of Alternative Air Filtration Materials and Methods of Analysis

Abstract: Development of high efficiency particulate air (HEPA) filters demonstrate an effort to mitigate dangerous aerosol hazards at the point of production. The nuclear power industry installs HEPA filters as a final line of containment of hazardous particles. An exploration of analytical, experimental, computational, and machine learning models is presented in this dissertation to advance the science of air filtration technology. This dissertation studies, develops, and analyzes alternative air filtration materials and methods of analysis that optimize filtration efficiency and reduce resistance to air flow. Alternative nonwoven filter materials are considered for use in HEPA filtration. A detailed review of natural and synthetic fibers is presented to compare mechanical, thermal, and chemical properties of fibers to desirable characteristics for air filtration media. Digital replication of air filtration media enables coordination among experimental, analytical, ma-chine learning, and computational air filtration models. The value of using synthetic data to train and evaluate computational and machine learning models is demonstrated through prediction of air filtration performance, and comparison to analytical results. This dissertation concludes with discussion on potential opportunities and future work needed in the continued effort to advance clean air technologies for the mitigation of a global health and safety challenge.

21 Jun 2023

A History and Analysis of the WPA Exhibit of Black Art at the Fort Huachuca Mountain View Officers’ Club, 1943–1946

Abstract: The 1943 art exhibition at the Mountain View Officers’ Club (MVOC), Fort Huachuca, Arizona should be considered one of the most significant events in the intersection of American art, military history, and segregation. Organizers of the event, entitled Exhibition of the Work of 37 Negro Artists, anticipated it would boost soldiers’ morale because Fort Huachuca was a predominately Black duty station during WWII. This report provides a brief history of Black art in the early 20th century, biographies of the artists showcased, and provides information (where known) about repositories that have originals or reproductions of the art today. The following is recommended: the General Services Administration (GSA) investigate the ownership of the pieces described in this report and if they are found to have been created under one of the New Deal art programs to add them to their inventory, further investigation be performed on the provenance and ownership of Lew Davis’s The Negro in America’s Wars mural, for the rehabilitation of the MVOC that the consulting parties agree upon the scope of the reproduction of the art, and request archival full reproductions of the pieces of art found in the collection of the Howard University Gallery of Art.

21 Jun 2023

Comparison of the Quantitation of Heavy Metals in Soil Using Handheld LIBS, XRFS, and ICP-OES

Abstract: Handheld laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique that shows the potential to replace X-ray fluorescence spectroscopy (XRFS) in the field characterization of soils containing heavy metals. This study explored the accuracy and precision of handheld LIBS for analyzing soils containing copper and zinc to support LIBS as a re-placement for XRFS technology in situ. Success was defined by handheld LIBS results that could be replicated across field analyzers and verified by inductively coupled plasma–optical emission spectrometry (ICP-OES). A total of 108 soil samples from eight military installations were pressed into 13 mm pellets and then analyzed by XRFS and LIBS. Handheld LIBS has a spot-size area 100-fold smaller than that of XRFS, and though it provided accurate measurements for NIST-certified reference materials, it was not able to measure unknown soils of varying soil texture with high particle size variability, regardless of sample size. Thus, soil sample particle size heterogeneity hindered the ability to provide accurate results and replicate quantitation results across LIBS and XRFS. Increasing the number of particles encountered by each shot through particle size reduction improved both field-analyzer correlation and the correlation between handheld LIBS and ICP-OES from weak (<15%) to strong (>80%).

20 Jun 2023

3D Mapping and Navigation Using MOVEit

Abstract: Until recently, our focus has been primarily on the development of a low SWAP-C payload for deployment on a UGV that leverages 2D mapping and navigation. Due to these efforts, we are able to autonomously map and navigate very well within flat indoor environments. This report will explore the implementation of 3D mapping and navigation to allow unmanned vehicles to operate on a variety of terrains, both indoor and outdoor. The method we followed uses MOVEit, a motion planning framework. The MOVEit application is typically used in the control of robotic arms or manipulators, but its handling of 3D perception using OctoMaps makes it a promising software for robots in general. The challenges of using MOVEit outside of its intended use case of manipulators are discussed in this report.

16 Jun 2023

Evaluation of a Permeable Dam as an Erosion Control Structure on Coca River, Ecuador

Abstract: The effort performed here describes the process to evaluate the scour-protection performance of the proposed permeable dam. The US Engineer Research and Development Center, Coastal and Hydraulics Laboratory, built a 1:50 Froude scaled movable bed section model of the permeable dam structure and tested in a specialized flume that simulates regressive erosion propagation. Profiles were collected at various times to track the progression of the scour. Tests evaluated variations of the proposed structure, which included tetrapods, riprap, bridge piers, and longitudinal piles. For the various proposed alternatives, a total of six tests were conducted. The collected profiles show the ability or inability of each alternative and its associated performance. From this analysis, untethered tetrapods could not effectively arrest the local scour around the structure. However, large rock along with invert control stopped the regressive erosion and held the upstream grade.

15 Jun 2023

ERDC R&D Strategy: Connecting the Dots to Innovation

Abstract: The Engineer Research and Development Center (ERDC) Board of Directors establishes the organization’s vision, mission, values and strategy. The strategy is determined by our vision and mission; it is guided by our values; and it is influenced by key national priorities and needs.

7 Jun 2023

Investigating Minimum Exposure Time Requirements of Diquat for Flowering Rush (Butomus umbellatus) Control

PURPOSE: The purpose of this study was to investigate the minimum exposure time requirements for submersed treatments of diquat to effectively control flowering rush (Butomus umbellatus L.). Identifying these parameters will provide critical information for the operational management of this species in high water exchange scenarios.

6 Jun 2023

Testing the Compatibility of the Sediment Budget Analysis System 2020 with Various Data Sources

Abstract: This Regional Sediment Management technical note (RSM TN) provides the workflow for implementing results of various toolsets into the Sediment Budget Analysis System (SBAS). SBAS is a commonly used toolset developed by the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL) for creating and visualizing sediment budgets. Recent upgrades to SBAS have warranted an investigation into its ability to accurately accept various data sources. Three case studies are presented showcasing the variety of acceptable tools, both ERDC-CHL published and custom-user created.