15 Sep 2025

Fiber-Reinforced-Polymer (FRP) Composite Sandwich Panel Barge Impact Modeling and Repair Testing: Dynamic and Static Finite Element Analysis (FEA) Predictions for Impact and Flexural Testing Validated with Experiments

Abstract: The US Army Engineer Research and Development Center has studied the functionality, durability, and structural integrity of fiber-reinforced-polymer (FRP) composite materials in civil works infrastructure. Compared to traditional materials like steel, composites offer a high strength-to-density ratio and excellent resistance to environmental degradation. The purpose of this study is to evaluate the dynamic response of FRP composite sandwich panels subjected to a barge impact with typical masses and velocities. A finite element model was created for FRP composite sandwich panels by incorporating cohesive interaction properties to evaluate the damage between three-dimensional (3D) layers. To validate the model, several FRP composite sandwich panels were experimentally subjected to low-velocity impacts and compared to the models. Moreover, flexural experiments were performed to determine the reduction of structural performance after impact and the efficacy of two different repair methods. Numerical predictions were developed to explore the damage caused by the interfaces of FRP composite layers. Load, deflection, and velocities were obtained experimentally and with finite element models.

12 Sep 2025

Veterans Administration Fourth Generation Historic Context

Abstract: The period of significance for fourth generation of Veterans Administration (VA) medical centers ranges from 1955 to 1977. This period encapsulates a surge of VA medical center construction with congressional funding, dating from the release of the 1955 congressional report Nonbed Betterments in Veterans Administration Hospitals—Need for Renovation and Construction to the adoption of the Veterans Administration Medical Facilities Acquisition Act of 1977. New medical centers constructed by the VA during this time may be eligible under Criterion A for their association with health care and medicine, specifically the development of education and research relationships with medical schools. These partnerships advanced therapies, technology, and hospital operation in support of the VA’s mission to provide quality medical care for veterans. To support these partnerships, VA medical centers were commonly built adjacent to or within medical school complexes. Additionally, fourth generation VA medical centers may be eligible under Criterion C for embodying distinctive architecture or landscape architecture characteristics of mid-century modern hospitals or representing an important contribution in a significant architect’s career. This report provides a comprehensive historic context for the design, construction, and operation of new fourth generation VA medical centers in support of Section 110 of the National Historic Preservation Act of 1966 (NHPA). It does not include other VA medical facilities constructed during this period, such as psychiatric and rehabilitation centers, nursing homes, domiciliaries, and research and education buildings.

12 Sep 2025

Arkansas City to Vicksburg Adaptive Hydraulics Model

PURPOSE: The purpose of this study is to develop and validate a 2D, depth-averaged hydrodynamic model of the Mississippi River from Vicksburg, Mississippi, to Arkansas City, Arkansas, to accurately replicate low-flow conditions. The model will be used to support an ongoing effort for the development of a low-water forecast model to aid navigational resilience.

12 Sep 2025

Identifying Hydric Soils Using α,α′-Dipyridyl Dye

Purpose: The application of α,α′-dipyridyl dye (pronounced alpha, alpha di-peeri-dill) provides a reliable and defensible mechanism for documenting the presence of reduced iron in support of hydric soil identification and wetland delineation activities. The α,α′-dipyridyl dye has proven particularly useful for identifying hydric soils in naturally problematic, altered, and disturbed soils. The proper application of paper test strips embedded with α,α′-dipyridyl dye further promotes the use of this technique to improve wetland delineation and management. This technical note summarizes the state of the science related to α,α′-dipyridyl dye and provides practitioner recommendations for applying, documenting, and interpreting α,α′-dipyridyl dye in hydric soil and wetland investigations.

12 Sep 2025

Quantifying Wild Pig Damage Reduction Using Before-After-Control-Impact Design at USACE Richard K. Yancey, Louisiana

Abstract: The FY23 research presented in this report is year three of a 3-year research plan to develop a user-friendly ecological-economic framework for rapid assessment of wild pig damage to wetlands. Building off research and findings from the FY21 and FY22 efforts conducted at Somerville Lake, Texas, the FY23 research focused on adapting the sampling frame-work to a forested wetland using a more advanced method for the extrapolation of damage to the whole study area, refining the economic valuation approach with machine-learning techniques, and improving the setup of the before-after-control-impact (BACI) study design estimating damage reduction after a targeted control effort. We estimate that the benefits provided by wetlands lost to wild pigs over a 1-year period in the Richard K. Yancey Wildlife Management Area study area was $234,486 (80% confidence interval, $63,155 to $691,220), and the aerial gunning control effort in the treatment plot provided a 243% return on investment in terms of damages avoided to wetlands.

12 Sep 2025

Literature Review and Environmental Concerns Regarding Lithium-Ion Batteries

Abstract: This study investigates the environmental and technical challenges associated with the production, use, and recycling of lithium-ion batteries (LIBs), which are critical components in consumer electronics and electric vehicles (EVs). As the demand for LIBs continues to grow, the concerns related to the mining and processing of key materials like lithium, cobalt, nickel, and manganese are also increasing. The extraction and refining processes for these metals are energy-intensive and produce significant environmental impacts, including greenhouse gas emissions, toxic waste, and resource depletion. The review emphasizes the need for improved recycling technologies and sustainable practices to mitigate the environmental footprint of LIBs and secure a more sustainable supply chain for the future of clean energy storage solutions. This study also analyzes LIB components to assess the presence of environmentally hazardous metals and compounds. Advanced analytical techniques like X-ray fluorescence (XRF), inductively coupled plasma–optical emission spectroscopy (ICP-OES), and Fourier transform infrared (FTIR) spectroscopy revealed significant leaching of toxic elements and PFAS from battery parts, underscoring the environmental and health risks associated with improper disposal. The findings highlight the urgent need for improved recycling methods to mitigate these risks and enhance the sustainability of LIB use.

11 Sep 2025

Influence and Mechanisms of Mineral Chemistry and Sizing Effects on Cementitious and Pozzolanic Reactions

Abstract: This study investigated whether materials traditionally considered inert could become reactive with increased fineness. Researchers used multiple techniques to produce materials in a variety of fineness levels. The final products were then analyzed for pozzolanic reactivity in accordance with ASTM 1897 and for their influence on portland cement hydration in accordance with ASTM C1702. Results indicated that pozzolanic reactivity was not produced by successive grinding for either chemistry, at least within the limits of the techniques used. Both chemistries were shown to influence the rate of portland cement hydration when ground finer than cement. This phenomenon is known as the filler effect, and it became more significant with increased fineness.

11 Sep 2025

A Calibration Method for Projecting Future Extremes via a Linear Mapping of Parameters

Abstract: In order to study potential impacts arising from climate change, future projections of numerical model output often must be calibrated to be comparable to observations. Rather than calibrating the data values themselves, we propose a novel statistical calibration method for extremes that assumes there exists a linear relationship between parameters associated with model output and parameters associated with observations. This approach allows us to capture uncertainty in both parameter estimates and the linear calibration, which we achieve via bootstrap. To focus on extreme behavior, we assume both model output and observations have distributions composed of a mixture model combining a Weibull distribution with a generalized Pareto distribution for the tail. A simulation study shows good coverage rates. We apply the method to project future daily-averaged river runoff at the Purgatoire River in southeastern Colorado.

11 Sep 2025

Effect of Gypsum on Transport of IMX-104 Constituents in Overland Flow Under Simulated Rainfall

Abstract: Residue of energetic formulations, deposited on military training grounds following incomplete detonation, poses biotic hazards. This residue can be transported off-site, adsorb to soil clays and organic matter, transform or degrade, or taken up by plants and animals. Its harmful effects can be mitigated by localizing the energetics at the initial deposition using soil amendments and allowing them to bio- and photodegrade in situ. Small plots with coarse loamy soil were used to study the effect of gypsum on transport and redistribution under simulated rainfall of various sizes of insensitive munition explosive IMX-104 particles. The addition of gypsum more than doubled infiltration and decreased sediment loss by 16%. The post-rainfall mass balance of IMX-104 in the order from greater to smaller pools was: (1) soil surface retention, (2) off-site loss to overland flow, and (3) sub-surface infiltration. The application of gypsum decreased concentration and the total mass loss of dissolved DNAN, RDX, and HMX in surface runoff. In addition, gypsum significantly decreased or delayed the peak discharge of <2mm particulate energetics. Gypsum shifted the total mass balance of energetics toward subsurface flow. This study indicates gypsum may decrease off-site transport of energetic constituents in the soils subject to surface sealing.

10 Sep 2025

Snow Depth Measurements from Arctic Tundra and Boreal Forest Collected During NASA SnowEx Alaska Campaign

Abstract: Boreal forest and Arctic tundra environments collectively hold the largest percentage of global terrestrial seasonal snow cover. Тhe in-situ snow measurement network is sparse and costly in these remote northern regions. Here, we complement existing snow depth monitoring in Arctic tundra and boreal forest by presenting an extensive (64°N–70°N) snow depth dataset and description of ground-based snow depth measurements collected during the NASA SnowEx Alaska intensive field campaign, March 7–16, 2023. We also report the accuracy of snow depth measurements in shallow boreal forest and Arctic tundra snowpack and share considerations in developing the consistent and repeatable snow depth data collection procedures. Snow depth measurements and technical validation described in this paper can serve as a robust product for testing snow remote sensing techniques, and for providing a reference dataset for climatological and hydrological studies.