7 Nov 2022

Dissolution of NTO, DNAN, and Insensitive Munitions Formulations and Their Fates in Soils: SERDP ER-2220

Abstract: The US military is interested in replacing TNT (2,4,6-trinitrotoluene) and RDX (1,3,5-hexahydro-1,3,5-trinitro-1,3,5-triazine) with DNAN (2,4-dinitroanisole) and NTO (3-nitro-1,2,4-triazol-5-one), which have similar explosive characteristics but are less likely to detonate unintentionally. Although these replacements are good explosives, basic information about their fate and transport was needed to evaluate their environmental impact and life-cycle management. This project measured their dissolution, photodegradation, and how aqueous solutions interact with soils, data critical to determining exposure potential and, consequently, risk.

4 Nov 2022

Environmentally Informed Buried Object Recognition

The ability to detect and classify buried objects using thermal infrared imaging is affected by the environmental conditions at the time of imaging, which leads to an inconsistent probability of detection. For example, periods of dense overcast or recent precipitation events result in the suppression of the soil temperature difference between the buried object and soil, thus preventing detection. This work introduces an environmentally informed framework to reduce the false alarm rate in the classification of regions of interest (ROIs) in thermal IR images containing buried objects. Using a dataset that consists of thermal images containing buried objects paired with the corresponding environmental and meteorological conditions, we employ a machine learning approach to determine which environmental conditions are the most impactful on the visibility of the buried objects. We find the key environmental conditions include incoming short-wave solar radiation, soil volumetric water content, and average air temperature. For each image, ROIs are computed using a computer vision approach and these ROIs are coupled with the most important environmental conditions to form the input for the classification algorithm. The environmentally informed classification algorithm produces a decision on whether the ROI contains a buried object by simultaneously learning on the ROIs with a classification neural network and on the environmental data using a tabular neural network. On a given set of ROIs, we have shown that the environmentally informed classification approach improves the detection of buried objects within the ROIs.

2 Nov 2022

Willis Coupling in One-dimensional Layered Bulk Media

Abstract: Willis coupling, which couples the constitutive equations of an acoustical material, has been applied to acoustic metasurfaces with promising results. However, less is understood about Willis coupling in bulk media. In this paper a multiple-scales homogenization method is used to analyze the source and interpretation of Willis coupling in one-dimensional bulk media without any hidden degrees of freedom, or one-dimensional layered media. As expected from previous work, Willis coupling is shown to arise from geometric asymmetries, but is further shown to depend greatly on the measurement position. In addition, a discussion of the predicted material properties, including Willis coupling, of macroscopically inhomogeneous media is presented.

1 Nov 2022

Snow-Covered Region Improvements to a Support Vector Machine-Based Semi-Automated Land Cover Mapping Decision Support Tool

Abstract: This work builds on the original semi-automated land cover mapping algorithm and quantifies improvements to class accuracy, analyzes the results, and conducts a more in-depth accuracy assessment in conjunction with test sites and the National Land Cover Database (NLCD). This algorithm uses support vector machines trained on data collected across the continental United States to generate a pre-trained model for inclusion into a decision support tool within ArcGIS Pro. Version 2 includes an additional snow cover class and accounts for snow cover effects within the other land cover classes. Overall accuracy across the continental United States for Version 2 is 75% on snow-covered pixels and 69% on snow-free pixels, versus 16% and 66% for Version 1. However, combining the “crop” and “low vegetation” classes improves these values to 86% for snow and 83% for snow-free, compared to 19% and 83% for Version 1. This merging is justified by their spectral similarity, the difference between crop and low vegetation falling closer to land use than land cover. The Version 2 tool is built into a Python-based ArcGIS toolbox, allowing users to leverage the pre-trained model—along with image splitting and parallel processing techniques—for their land cover type map generation needs.

26 Oct 2022

The Impact of Practitioners’ Personality Traits on Their Level of Systems-Thinking Skills Preferences

Abstract: In this study, we used a structural equation modeling method to investigate the relationship between systems engineers and engineering managers’ Systems-Thinking (ST) skills preferences and their Personality Traits (PTs) in the domain of complex system problems. As organizations operate in more and more turbulent and complex environments, it has become increasingly important to assess the ST skills preferences and PTs of engineers. The current literature lacks studies related to the impact of systems engineers and engineering managers’ PTs on their ST skills preferences, and this study aims to address this gap. A total of 99 engineering managers and 104 systems engineers provided the data to test four hypotheses posed in this study. The results show that the PTs of systems engineers and engineering managers have a positive impact on their level of ST skills preferences and that the education level, the current occupation type, and the managerial experience of the systems engineers and engineering managers moderate the main relationship in the study.

25 Oct 2022

Numerical Modeling of Mesoscale Infrasound Propagation in the Arctic

Abstract: The impacts of characteristic weather events and seasonal patterns on infrasound propagation in the Arctic region are simulated numerically. The methodology utilizes wide-angle parabolic equation methods for a windy atmosphere with inputs provided by radiosonde observations and a high-resolution reanalysis of Arctic weather. The calculations involve horizontal distances up to 200 km for which interactions with the troposphere and lower stratosphere dominate. Among the events examined are two sudden stratospheric warmings, which are found to weaken upward refraction by temperature gradients while creating strongly asymmetric refraction from disturbances to the circumpolar winds. Also examined are polar low events, which are found to enhance negative temperature gradients in the troposphere and thus lead to strong upward refraction. Smaller-scale and topographically driven phenomena, such as low-level jets, katabatic winds, and surface-based temperature inversions, are found to create frequent surface-based ducting out to 100 km. The simulations suggest that horizontal variations in the atmospheric profiles, in response to changing topography and surface property transitions, such as ice boundaries, play an important role in the propagation.

13 Oct 2022

Data Acquisition Software for Impedance Tube Measurements

Abstract: Transmission impedance tube measurements are necessary to measure the asymmetric acoustic property known as Willis coupling. However, software is required to measure and store data from an impedance tube for acoustic material characterization. This report details the overall structure of custom-developed software built from low-level functions. Software libraries from the data acquisition system as well as the HDF5 file system are the basis for the code. A command line user interface guides a user through the necessary steps in data collection.

11 Oct 2022

A Review of Airfield Pavement Drainage Guidance

Abstract: Inadequate drainage conditions may lead to airfield pavement deterioration. A thorough review of existing pavement drainage guidance and literature was necessary to identify key drainage considerations such as surface drainage infrastructure, pavement drainage layer thickness, use of geotextiles, and performance in freeze–thaw climates. Existing airport drainage guidance is provided by the Unified Facilities Criteria (UFC), the Federal Aviation Administration (FAA), and the Tri-Service Pavements Working Group (TSPWG). Pavement drainage guidance is buried within regulations for pavement de-sign and can, at times, be split awkwardly to accommodate pavement guidance that is split between rigid and flexible designs. Most airfield pavement guidance has been adapted from guidance for highway design. Most guidance is also strength based, with little to no attention paid to material erodibility (a potential cause of pavement deterioration). This review also found very little reference to repairing, rather than completely replacing, damaged subsurface drainage layers. Further research is needed to assess the use of geofabrics and moisture in freeze–thaw conditions on drainage layers and surface structures. With further research, the retrofit and repair of existing subpavement systems might become a more economical solution to drainage-caused pavement deterioration issues than complete reconstruction.

6 Oct 2022

Incorporating Social and Environmental Outputs in Decision-Making: Workshop Outcomes

PURPOSE: This document summarizes the notable outcomes of the workshop “Quantifying and Incorporating Social and Environmental Outputs in Decision-Making—Research and Development Needs and Strategy Workshop.” The workshop was held 24 and 25 July 2019 in Alexandria, Virginia, at the US Army Corps of Engineers’ (USACE) Institute for Water Resources (IWR). The workshop sought to identify gaps in knowledge, methods, data, and tools and to identify types of subject matter experts who would be needed for the research team. A total of 22 participants attended the facilitated workshop, representing a broad array of expertise: economists, scientists, planners, social scientists, project managers, and researchers from a number of USACE organizations and partnering academics across the United States. Together, these attendees reviewed existing policy and research and prioritized future work to fill gaps in methods and procedures for incorporating social and environmental inputs across a broad range of USACE projects.

6 Oct 2022

Old Post Reevaluation, Fort Huachuca, AZ

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. Fort Huachuca is situated at the foot of the Huachuca Mountains in southern Cochise County, Arizona. It is located approximately 15 miles north of the border with Mexico and 75 miles southeast of Tucson. It was founded in 1877 as a frontier cavalry fort and remains one of the oldest military installations in the West. The objective of this report is to inventory the real property within Fort Huachuca’s Old Post, the historic core of the installation. Each resource is enumerated and accompanied by a list of reports discussing its potential NHL or NRHP eligibility. Subsequently, each resource is accompanied by a short description, which includes its location and current status within the recently created Old Post Historic District.