3 Sep 2025

Acute Toxicity of Carbon Nanotubes, Carbon Nanodots, and Cell-Penetrating Peptides to Freshwater Cyanobacteria

Abstract: Synthetic non-metallic nanoparticles have been explored to treat harmful algal blooms, but their strain-specific algicidal activities have been rarely investigated. Three batches of CNDs were prepared in-house using glucose or chloroform and methanol as the substrate and one batch of single-walled CNTs. The axenic laboratory culture of each cyanobacterial strain was exposed to an NMNP at two dosage levels for 48 h, followed by measurement of five endpoints. The endpoints were optical density at 680 nm for chlorophyll-a estimation, OD at 750 nm for cell density, instantaneous pigment fluorescence emission after being excited with 450 nm blue light for chlorophyll-a or 620 nm red light for phycocyanin, and quantum yield for photosynthesis efficiency of photosystem II. The results indicate the acute toxicity was strain-, NMNP type-, dosage-, and endpoint-dependent. The two benthic strains were more resistant to NMNP treatment. SWCNTs and fraction A14 of CND-G were more toxic than CND-G and CND-C/M. The CPP was the least toxic. The high dose generally caused more severe impairment. OD750 and OD680 were more sensitive and QY was the least sensitive. The strain dependence of toxicity suggested the potential application of these NMNPs as a target-specific tool for mitigating harmful cyanobacterial blooms.

29 Aug 2025

Nanofiber Fabrication by Electrospinning Technology: Optimization, Characterization, and Application

Abstract: This project explores electrospinning (ES) as one of the most successful technologies to produce nanofiber materials. Electrospun nanofibers are used in various military technologies, including advanced filtration systems, impact-resistant protective gear, thermal insulation, radar absorption for camouflage and stealth, antimicrobial wound dressings, drug-delivery patches, rapid healing, efficient solar cells, and self-cleaning materials for regeneration. Researchers at the US Army Engineer Research and Development Center (ERDC) investigated electrospinning effects on morphology, crystallinity and distribution of metal oxides for photocatalytic activities, and magnetic and mechanical properties in reinforcing composites. This study includes the following fabricated electrospun mats: -iron and titanium oxide (Fe3O4 and TiO2) with polyvinyl alcohol (PVA) -graphene, graphene oxide, and reduced graphene oxide with polyvinylidene fluoride (PVDF) -graphene-polyacrylonitrile (PAN) -metal-organic frameworks (MOF), graphene-MXene with PAN The research presented herein includes electrospinning theory, process, and parameters; sol–gel technology in solution preparation; and electrospinning sample characterization to guide readers in the fabrication of electrospun fibers with targeted characteristics. Future studies explore electrospun MOFs and MXene, a class of two-dimensional inorganic compounds with transition metal carbides, nitrides, or carbonitrides composites. These studies are invaluable for advancing military programs and enhancing warfighter support and civil works.

29 Aug 2025

Developing Conceptual Ecological Models for Hydraulic Analysis

Purpose: Technological advances, coupled with increased availability of spatial and monitoring data for hydraulic analysis, environmental flows analysis, and remote sensing, present opportunities for novel investigations of the structure and function of ecological systems. To leverage these capabilities in ecological analysis, it is necessary to develop a framework that links engineering model capacities with ecological principles. It is well known that riverine ecosystems are complex systems at the intersection of channel form, stream flow volume, and biology. However, because of differences in technical language and analytical philosophy, there are practical challenges associated with cross-walking multidiscipline riverine studies into interdisciplinary efforts that comprehend both engineering and ecological principles. Challenges associated with cross-discipline communication and framing the scope of ecohydraulic analysis are inherent barriers that limit the traction of research crossing disciplinary boundaries.

29 Aug 2025

Monitoring of Understudied Wetlands: State of Knowledge

Abstract: Some wetlands can present unique challenges for mapping and monitoring due to their size, location, foliage architecture, and spectral characteristics. For instance, assessing ecological condition and restoration success using traditional remote-sensing systems in forested and ephemeral wetlands is onerous. Therefore, the purpose of this technical note is to evaluate the state of knowledge and technology related to the use of remote sensing in assessing vegetation dynamics in understudied and hard to monitor wetlands. Ultimately, this exercise will identify data gaps and recommend improvements for analyzing and modeling wetland systems and trends, quantifying disturbance impacts, and assist efficiencies of data collection to improve management decisions, which in turn will help in reaching restoration goals.

29 Aug 2025

Adaptive Management Framework for Microseira wollei in Lake St. Clair, Michigan

Abstract: Microseira wollei has grown to problematic densities within Lake St. Clair, located between Lake Erie and Lake Huron. Though stakeholders have issued a call-to-action for the management of M. wollei, no substantive plan exists, which was the impetus for this adaptive management framework. Field surveys, emerging technologies, laboratory evaluations, and a literature review were integrated to develop this site-specific frame-work. Adaptive management consists of a series of iterative steps to define and characterize the issue; identify goals, plan, and prioritize; determine a plan; implement management; measure the outcomes; and adapt and re-fine the plan. M. wollei is widely distributed within the study area and across large sections of the lake bed. Due to its large spatial extent, long-term management should focus on regaining and maintaining uses within Lake St. Clair that have been affected by shoreline accumulations. Mechanical removal is anticipated to be the most effective tool; however, the potential addition of algaecides or nutrient sequestration products could be explored for increased effectiveness. The planning and execution of a substantive management plan for M. wollei in Lake St. Clair are outlined and described, but effective management will require a concerted effort on a scale that matches the scope of the problem.

27 Aug 2025

Evaluating Transport of Stockpiled Mississippi River System Sand for Beach Nourishment and Other Uses

The US Army Corps of Engineers (USACE), Rock Island and St. Paul Districts, maintain 876 miles of shallow-draft navigation channels, dredging approximately 2 million cubic yards of clean, fine- to medium-grained sands from these waterways annually. Due to system constraints and certain state regulatory policies, most of this dredged material (DM) is placed in upland and island facilities. As these dredge placement areas fill with sediment, the districts need to remove sediment to create additional storage or seek new land acquisition. While a significant amount of this DM is being locally used beneficially, the current uses are opportunity driven and dictated by proximity. As such, the districts continue to seek alternative beneficial use practices. One major limiting factor to increased beneficial use is the cost of material transport. Per the Federal Standard, USACE will use the least costly DM placement alternatives that are consistent with sound engineering practices and meet federal environmental requirements. Transport beyond traditional placement sites typically costs much more. The analysis described in this report reviews nontraditional transportation modes and routes to match distant needs with river sediment.

27 Aug 2025

Methods for 3D Printing Dredge Sediments to Sequester Contaminants

Purpose: This technical note describes methods for preparing dredged sediment and commercially available clay for 3D printing, focusing on achieving optimal consistency and properties for successful extrusion. These methods establish best practices for using dredged sediments in 3D printing applications.

27 Aug 2025

Demonstration of a Remotely Operated Vehicle for Inspecting the Chicago Electrical Fish Dispersal Barrier

Purpose: This report describes the US Army Engineer Research and Development Center (ERDC) application of a remotely operated vehicle to inspect an electrical fish dispersal barrier at the bottom of the Chicago Sanitary Ship Canal (CSSC) for the US Army Corps of Engineers–Chicago District.

22 Aug 2025

Cracking the Code: Linking Good Modeling and Coding Practices for New Ecological Modelers

Abstract: Good modeling practices are essential for producing reliable and reproducible ecological models. Inherent to good modeling practices are fundamental coding and documentation skills, which not only implement the desired modeling capabilities but also clearly outline the goals, methods, and components of a model necessary to reproduce desired results. Coding represents a significant barrier for entry into ecological modeling, since most ecologists have not had formal training in computer science or software development. While software packages do exist that facilitate model development, we have observed that newer modelers still struggle with developing good coding practice throughout the modeling process. During a series of agent-based modeling short-courses and full semester graduate courses, both taught in NetLogo, we identified some common challenges encountered by graduate students and environmental professionals as they learn to code an ecological model, many for the first time. We were able to categorize and provide examples of the main challenges and obstacles, which fell into three main groups that follow the steps of good modeling practice: problem scoping and conceptualization, formulation, and evaluation. We then provide guidance on how to overcome these obstacles while developing good coding and modeling practices that will result in more scientifically defensible models.

20 Aug 2025

Trade-offs Between Field and Remote Geomorphic Monitoring of Coastal Marsh Restoration Sites

Abstract: Coastal marsh restoration presents geomorphic monitoring challenges because these sites are often remote or inaccessible, and time and financial resources for field data may be limited. Yet, elevation and shoreline characteristics contribute to the overall health and longevity of coastal marshes. The expansion of Uncrewed Aircraft System (UAS) technology and new satellite platforms offer opportunities to complement ground-based geomorphic monitoring and overcome the challenges of traditional field methods. Here, we compare field-based and remote-sensing approaches to monitor two restored coastal wetlands in Louisiana. At Spanish Pass, methods for measuring site elevation, shoreline position, and shoreline geomorphic types were compared. Ground surveys strongly correlated with UAS-lidar digital elevation model (DEM) elevations (R2 = 0.97. UAS and satellite imagery were accurate to within 3 meters of field-shoreline positions, and UAS-lidar-derived shorelines had the lowest error. At LaBranche, UAS-lidar DEM data were paired with airborne lidar and legacy ground surveys to track temporal changes in elevation, indicating minimal elevation change. The study demonstrates the accuracy and utility of satellite and UAS remote sensing for monitoring shoreline positions and elevations but notes that shoreline classifications could be improved with additional quantification. These findings help practitioners assess the trade-offs and benefits of various monitoring methods.