19 Jul 2023

Adverse Outcome Pathways for Engineered Systems

Abstract: Companies and organizations around the world spend massive amounts of money each year to discover, predict, and remediate failures within engineered systems. These tasks require individuals with specialized knowledge in a variety of topics related to failure. This knowledge is often acquired through years of academic and on-the-job training centered around the review of scientific documentation such as books, reports, manuals, and peer-reviewed publications. The loss of this knowledge through employee attrition can be detrimental to a group as knowledge is often difficult to reacquire. The aggregation and representation of known failure mechanisms for engineered materials could aid in the sharing of knowledge, the acquisition of knowledge, and the discovery of failure causes, reducing the risk of failure. Thus, the current work proposes the Adverse Outcome Pathway for Engineered Systems (AOP-ES) framework, an extension of the Adverse Outcome Pathway used in toxicology. The AOP-ES is designed to document failure knowledge, enabling knowledge transfer and the prediction of failures of novel engineered materials based on the performance of similar materials. This paper introduces the AOP-ES framework and its key elements alongside the principles that govern the framework. An application of the framework is presented, and additional benefits are explored.

17 Jul 2023

Testing Expedient Ground Anchor Solutions for Guyed Towers in Remote Cold Regions: Considerations for Cold Remote Regions with Limited Tools

Abstract: Ground anchors connected to guy wires for tower structures in cold climates suffer from frost heaving, which causes loss of wire tension and subsequent structural instability. It is necessary to understand what ground anchors are available to resist this tendency yet are still capable of expedient installation in remote areas. To that end, three metal, traditional ground-anchor types (arrowhead, bullet, and penetrating auger) and one novel polyvinyl chloride (PVC) T-post anchor were evaluated in frozen gravels and frozen silts at a research facility in Fairbanks, Alaska. Criteria included installation capability, failure loading, and removal ability. Additionally, expedient installation techniques for use in field conditions were also demonstrated. All three traditional ground anchors failed to penetrate frozen gravels. The penetrating auger also failed to penetrate frozen silts, but the arrowhead and bullet anchors did penetrate frozen silts with difficulty. The PVC anchor is capable of being installed only in a predrilled pilot hole. Under flexural load, the arrowhead anchor cable failed at 3686.72 lb, and the bullet anchor cable failed at 1753.44 lb. The PVC slid out of its hole at a direct-pull force of 1978.24 lb and failed under flexural stress at 202.32 lb.

7 Jul 2023

Docker Containers and Images for Robot Operating System (ROS)–Based Applications

Abstract: Docker is a tool designed to make it easier to create, deploy, and run applications by using containers. Containers allow a developer to package and ship out an application with all of the parts it needs, such as libraries and other dependencies. Herein, we investigate using a Docker image to deploy and run our Robot Operating System (ROS)–based payload on a robot platform. Ultimately, this would allow us to quickly and efficiently deploy our payload on multiple platforms.

7 Jul 2023

Geomorphic Assessment of the St. Francis River: Between Wappapello Lake and Lake City

Abstract: The St. Francis River is a complex system that lies in the historic floodplain of the Mississippi and Ohio Rivers. The basin has undergone extensive anthropogenic modifications, including reservoir construction, large-scale channelization, and construction of leveed floodways. Several analyses of available gage data, lidar data, and historical research have provided a picture of geomorphic trends and an overall understanding of the river’s stability. The types of analysis used to determine trends included yearly low stage plots, stage-duration curves, specific gage analysis, water surface slopes, and stream power changes. The results from these analyses were synthesized to develop an overall assessment of the reach. Channel cutoffs resulted in a significant decrease in channel length and sinuosity and triggered geomorphic change throughout the river. Immediately following channelization, dramatic decreasing trends in stage were observed for Fisk and Dekyn’s Store, while St. Francis and Holly Island began to aggrade. Slopes and stream power were significantly increased for the upper portion of the study area and showed a decreasing trend for the lower reach.

6 Jul 2023

A Review of Sensor-Based Approaches for Monitoring Rapid Response Treatments of cyanoHABs

Abstract: Water quality sensors are dynamic and vary greatly both in terms of utility and data acquisition. Data collection can range from single-parameter and one-dimensional to highly complex multiparameter spatiotemporal. Likewise, the analytical and statistical approaches range from relatively simple (e.g., linear regression) to more complex (e.g., artificial neural networks). Therefore, the decision to implement a particular water quality monitoring strategy is dependent upon many factors and varies widely. The purpose of this review was to document the current scientific literature to identify and compile approaches for water quality monitoring as well as statistical methodologies required to analyze and visualize highly diverse spatiotemporal water quality data. The literature review identified two broad categories: (1) sensor-based approaches for monitoring rapid response treatments of cyanobacterial harmful algal blooms (cyanoHABs), and (2) analytical tools and techniques to analyze complex high resolution spatial and temporal water quality data. The ultimate goal of this review is to provide the current state of the science as an array of scalable approaches, spanning from simple and practical to complex and comprehensive, and thus, equipping the US Army Corps of Engineers (USACE) water quality managers with options for technology-analysis combinations that best fit their needs.

6 Jul 2023

A General-Purpose Multiplatform GPU-Accelerated Ray Tracing API

Abstract: Real-time ray tracing is an important tool in computational research. Among other things, it is used to model sensors for autonomous vehicle simulation, efficiently simulate radiative energy propagation, and create effective data visualizations. However, raytracing libraries currently offered for GPU platforms have a high level of complexity to facilitate the detailed configuration needed by gaming engines and high-fidelity renderers. A researcher wishing to take advantage of the performance gains offered by the GPU for simple ray casting routines would need to learn how to use these ray tracing libraries. Additionally, they would have to adapt this code to each GPU platform they run on. Therefore, a C++ API has been developed that exposes simple ray casting endpoints that are implemented in GPU-specific code for several contemporary device platforms. This API currently supports the NVIDIA OptiX ray tracing library, Vulkan, AMD Radeon Rays, and even Intel Embree. Benchmarking tests using this API provide insight to help users determine the optimal backend library to select for their ray tracing needs. HPC research will be well-served by the ability to perform general purpose raytracing on the increasing amount of graphics and machine learning nodes offered by the DoD High Performance Computing Modernization Program.

5 Jul 2023

Load and Resistance Factors from Reliability Analysis Probability of Unsatisfactory Performance (PUP) of Flood Mitigation, Batter Pile-Founded T-Walls Given a Target Reliability Index (𝛽)

Abstract: This technical report documents the research and development (R&D) study in support of the development of a combined Load and Resistance Factor Design (LRFD) methodology that accommodates both geotechnical and structural design limit states for design of the US Army Corps of Engineers (USACE) batter pile-founded, reinforced concrete flood walls. Development of the required reliability and corresponding LRFD procedures has been progressing slowly in the geotechnical topic area as compared to those for structural limit state considerations, and therefore this has been the focus of this first-phase R&D effort. This R&D effort extends reliability procedures developed for other non-USACE structural systems, primarily bridges and buildings, for use in the design of batter pile-founded USACE flood walls. Because the foundation system includes batter piles under flood loading, the design procedure involves frame analysis with significant soil structure interaction. Three example batter pile-founded T-Wall flood structures on three different rivers have been examined considering 10 geotechnical and structural limit states. Numerical procedures have been extended to develop precise multiple limit state Reliability calculations and for complete LRFD analysis of the example batter pile-founded, T-Wall reinforced concrete, flood walls.

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.