7 May 2026

Surface Oxide Removal in Preparation for Controlled Liquid Metal Embrittlement

Abstract: During liquid metal embrittlement a liquid metal infiltrates grain boundaries of a compatible solid metal, interrupting the inter-grain bonds and weakening the metal. Ongoing research has proposed that this effect may be used to perform additive/subtractive hybrid machining to fabricate replacement components, using relatively simple equipment and low material and instrument costs. The gallium/aluminum pairing is of particular interest due to the usage of aluminum in a wide variety of structural and aerospace applications coupled with gallium’s nontoxicity and melting point just above room temperature, which facilitates storage and transport. To activate aluminum to gallium infiltration, the surface oxide formed on aluminum in atmosphere must first be removed simultaneously with a significant amount of bulk metal to promote flow control of the liquid metal. Three targeted techniques for oxide removal were tested and compared, specifically mechanical abrasion, chemical etching, and laser ablation. Mechanical abrasion is simple to implement but lower precision. Chemical etching requires significant prep work and cleanup but could operate on entire sheets of substrate simultaneously with proper masking. Although laser ablation requires the most complex instrumentation, it requires minimal prep work and provides the greatest precision, making it ideal for the manufacturing application under development here.

7 May 2026

Tribological Properties of Synthetic and Biosourced Lubricants Enhanced by Graphene and Its Derivatives: A Review

Abstract: This review explores the tribological properties of biosourced lubricants (biolubricants) enhanced by graphene (Gr) and its derivatives and hybrids. Friction and wear at mechanical interfaces are the primary causes of energy loss and machinery degradation, necessitating effective lubrication strategies. Traditional lubricants derived from mineral oils present environmental challenges, leading to an increased interest in biolubricants derived from plant oils and animal fats. Biolubricants offer high biodegradability, renewability, and low toxicity, positioning them as ecofriendly alternatives. This work extensively reviews the role of Gr-based nanoadditives in enhancing the lubrication properties of biolubricants. Gr with its exceptional physicomechanical properties has shown promise in reducing friction and wear. The review covers various Gr derivatives, including Gr oxide (GO) and reduced Gr oxide (r-GO), and their performance as lubrication additives. The discussion extends to Gr hybrids with metals, polymers, and other 2D materials, highlighting their synergistic effects on the tribological performance. The mechanisms through which these additives enhance lubrication, such as the formation of protective films and improved interactions between lubricants and tribopairs, are examined. Emphasis is placed on the environmental benefits and potential performance improvements of Gr-based biolubricants. Finally, by analyzing current research and technological trends, the paper outlines future prospects for optimizing lubricant formulations with Gr-based nanoadditives, aiming for more sustainable and efficient tribological applications.

4 May 2026

Insight into the Photocatalytic Degradation Mechanism for “Forever Chemicals” PFNA by Reduced Graphene Oxide/WO3 Nanoflower Heterostructures

Abstract: Water contamination with “forever chemicals” like per- and polyfluoroalkyl substances (PFAS) poses significant toxicity to the environment. Since they are the most persistent synthetic chemicals that hardly degrade in the natural environment and are carcinogenic to humans, there is an urgent need to discover novel processes for destroying PFAS. Herein, we report on the design of a reduced graphene oxide (r-GO)/WO3 nanoflower (WO3-NF)-based heterostructure for harnessing 365 nm light-driven photocatalytic oxidation and reduction process toward the photocatalytic degradation of perfluorononanoic acid (PFNA). Moreover, reported data reveal that using an r-GO/WO3-NF heterostructure photocatalyst, 100% PFNA degradation and 14% defluorination can be achieved in the presence of isopropyl alcohol as the hydroxy radical (•OH) quencher or glucose as a hot hole (h+) quencher after exposure to 365 nm light for 22 h. A reported mechanistic study shows synergistic oxidation and reduction processes are vital for the complete degradation of PFNA, where the hydrated electron (eaq−) plays a key role as a reducing agent and h+ and •OH act as oxidation agents. Furthermore, the photocatalytic destruction mechanism study indicates that chain shortening via C−C bond breaking and defluorination via C−F bond breaking are major pathways for PFNA degradation. A wavelength-dependent study shows that only 22% degradation can be achieved after exposure to 532 nm light for 22 h, which is due to the lack of the formation of hydrated electrons (eaq−). The current study sheds light on the construction of the r-GO/WO3 NF heterojunction for the highly efficient degradation of PFAS.

4 May 2026

Erosion Test Database Reassessment with Application to Engineered Soils

Abstract: This report presents a reevaluation of the soil erosion property relation-ships and a reanalysis of the data with a specific focus on compacted and engineered fill materials. Reinterpretation first centered on describing the parametric space of the database in which the models’ ability to predict critical shear stress and the erodibility coefficient parameter have the greatest uncertainty. Second, this work considered the smaller subset of the dataset with only engineered fill and compacted materials. However, considering only this subset was not found to reduce significantly the uncertainty in predictive capability. We recommend additional work to expand the dataset, focusing on materials in conditions more representative of the compacted and aged soils present on many flood control infrastructure projects.

4 May 2026

An Investigation of Causes of Inaccuracy of Infrared Radiation Cameras for Large-Scale Additive Manufacturing Applications

Abstract: In additive manufacturing, accurate temperature data are needed for both real-time feedback for print operators and understanding the thermomechanical behavior for prediction and part quality characterization. Through the collection of accurate temperature data, thermal models can be validated to predict process-induced properties of parts. Infrared radiation (IR) is used to determine the temperature of a surface. Because IR cameras measure thermal radiation from a distance without contact, they are safe to use in high-temperature environments like 3D printing. An investigation of reported temperature values for multiple cameras during one print showed a decreasing trend for cameras close to the printer’s heat sources, which was not reflective of the printing process, and a discrepancy of ±20°C when printing at 200°C across overlapping camera views. Two more prints were studied to determine whether this camera behavior was unique to that print and geometry. The analysis showed the same results across all three prints, with camera-reported values having inconsistencies for a single layer, a subset of layers, and the scale of the print. Multiple possibilities for the cameras’ variances were explored. The IR cameras were determined to require further calibration and experimentation before reported temperature values can be treated as physical temperature values.

29 Apr 2026

Bridge Load Rating for US Army Installations: Guidance

Abstract: This report summarizes Army policy and provides technical guidance for the load rating of vehicular and railroad bridges on US Army installations. These bridges must be load rated to determine and ensure their abilities to support the Army’s heavy military vehicles as well as all public-sector cars, trucks, or trains (in the case of railroad bridges). Installation bridge management and load ratings are accomplished under the Installation Management Command (IMCOM) Army Dams and Transportation Infrastructure Program (ADTIP), with technical support from the US Army Engineer Research and Development Center (ERDC).

29 Apr 2026

Deep Learning Approaches for Buried Object Detection in Infrared Imagery

Abstract: Artificial intelligence and machine learning techniques are increasingly utilized to detect buried objects in thermal infrared imagery. This task relies heavily on the quality and diversity of the training dataset, requiring datasets that capture variability present in real-world environments. Synthetic imagery offers a means to expose algorithms to a greater range of conditions than is often available in real-world data alone. This study evaluates the performance of three open-source object detection models—Faster Region-Based Convolutional Neural Network (R-CNN), You Only Look Once (YOLOv8), and Single Shot Multibox Detector—trained using real-world, synthetic, and hybrid datasets. Real-world imagery was collected from a single field site, while synthetic data were generated using the Virtual Environmental Simulation for Physics-Based Analysis software suite. Model performance was evaluated using Intersection over Union and confidence scores. Models trained exclusively on synthetic datasets with limited scene diversity, when tested on real-world imagery from the same location, produce high false-positive and false-negative rates. Detection performance im-proved significantly for Faster R-CNN and YOLOv8 when trained using a hybrid dataset combining real-world and synthetic data. Analysis of red-green-blue histograms revealed differences in pixel intensity distributions between real and synthetic imagery, indicating areas for improving synthetic data generation.

29 Apr 2026

Forward Operating Remote Camera for Engineering—Construction Assurance and Monitoring (FORCE-CAM), Generation 1

Abstract: This research delivered a first-generation, real-time construction monitoring capability, enabling visual situational awareness for off-site subject matter experts. The live-streamed and recorded data can be visualized from a remote computer desktop to aid in identifying non-conformance issues during active paving operations or during concrete damage assessment and repair operations. Experimentation on asphalt paving and skid-steer construction equipment using direct electro-optical and thermal sensors provided validation of the efficacy of this solution.

22 Apr 2026

Statistical Analysis of Large Format Additively Manufactured Polyethylene Terephthalate Glycol with 30% Carbon Fiber Tensile Data

Abstract: In large format additive manufacturing (LFAM), a keener understanding of the relationship between the manufacture method and material temperature dependency is needed for the production of large polymer parts. Statistical analyses supported by material properties and a meso-structural understanding of LFAM are applied to elucidate tensile data trends. The data from LFAM polyethylene terephthalate glycol with 30% carbon fiber (CF) (PETG CF30%) panels (diagonal, horizontal, and vertical in the x-y print plane) and injection-molded specimens tensile tested at six different testing temperatures (room temperature, 40 ◦C, 50 ◦C, 60 ◦C, 70 ◦C, and 80 ◦C) were used for statistical analyses. A standard deviation, a coefficient of variation, and a two-way and one-way analyses of variance (ANOVA) were conducted. The manufacturing method (44.2%) and temperature (47.4%) have a strong effect on the ultimate tensile strength, in which temperature (82.6%) dominates Young’s modulus. To explain the difference between the ultimate tensile strength of vertical, diagonal, and horizontal specimens at room temperature, a visual inspection of the specimen failure was conducted and the maximum stress at the crack tip was calculated analytically. The decreased strength in the diagonal specimens resulted from the reliance on interlaminar adhesion strength. Future work will consider the effect of the void space variation on tensile strength variance.

22 Apr 2026

Mesoscale Modeling and Parametric Studies of Concrete Materials

Abstract: This research focused on creating a mesoscale finite element model of concrete, treating it as a three-phase composite material composed of coarse aggregates, mortar, and the Interfacial Transition Zone (ITZ). The objective was to understand how these mesoscale structures influence the material's properties and responses under various loading conditions. The model simulated a normal-strength concrete with a compressive strength of approximately 27 MPa. The simulations included unconfined uniaxial compression, hydrostatic compression, uniaxial strain compression and triaxial compression, with the model's dimensions and boundary conditions mirroring those of laboratory tests on cylindrical specimens. The results from the simulations corresponded well with experimental data, validating the accuracy of the modeling method. Further parametric studies were conducted to examine how attributes like aggregate volume fraction and material properties impact the concrete's overall performance. This validated modeling provides a reliable pathway for optimizing concrete materials for specific uses, such as designing hardened structures for military applications. It also offers a method for estimating concrete properties when laboratory testing is limited or unavailable.