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  • Commitment to high-quality blue roof installations for Ida survivors

    Water-logged floorboards. Moldy sheetrock. Broken windows. Desperation. For many survivors of Hurricane Ida, the storm itself was not the worst part—the worst of their experience was the growing anxiety of watching their homes quickly deteriorate every day it was left exposed to the elements.

  • Volunteers clean up Lake Cumberland on National Public Lands Day

    SOMERSET, Ky. (Sept. 28, 2021) – More than 120 volunteers collected 276 bags of trash, 53 agricultural and car tires, old dock flotation, a metal railing with stairs, and a doghouse during a community effort to clean up Lake Cumberland on National Public Lands Day.

  • Corps seeks comments on riverbank stabilization project near Morton, MN

    The U.S. Army Corps of Engineers, St. Paul District, is seeking comments on its draft Environmental Assessment of the Lower Sioux Indian Community Tribal Partnership Program Feasibility Study.

  • Operation Blue Roof sign-up deadline Sept. 30

    The U.S. Army Corps of Engineers Blue Roof program Sept. 30 deadline is close, for the residents who sustained Hurricane Ida damage in the 25 eligible parishes in southeastern Louisiana.

  • U.S. Army Corps of Engineers Announces Contract Award for St. Albans Columbarium Project

    NEW YORK – The U.S. Army Corps of Engineers, New York District, recently awarded a contract for

  • Temporary Recreation Area Closings at Lake Shelbyville for Youth Deer Hunt

    Lake Shelbyville – The U.S. Army Corps of Engineers will hold a youth deer hunt at Lake Shelbyville on October 9 & 10, 2021. The hunt will be conducted in portions of recreation areas previously closed for the season. As a safety precaution Lone Point Campground, excluding the boat ramp and Walleye Group Camp, Whitley Creek campground and treatment plant, excluding the boat ramp and all Wilborn Creek, Sullivan Beach, and Opossum Creek Recreation Areas will be closed to vehicle and pedestrian traffic from 12:00 p.m. October 8, 2021 to 8:00 p.m. October 10, 2021.

  • Backward Erosion Progression Rates from Small-Scale Flume Tests

    Abstract: Backward erosion piping (BEP) is an internal erosion mechanism by which erosion channels progress upstream, typically through cohesionless or highly erodible foundation materials of dams and levees. As one of the primary causes of embankment failures, usually during high pool events, the probability of BEP-induced failure is commonly evaluated by the U.S. Army Corps of Engineers for existing dams and levees. In current practice, BEP failure probability is quantitatively assessed assuming steady state conditions with qualitative adjustments for temporal aspects of the process. In cases with short-term hydraulic loads, the progression rate of the erosion pipe may control the failure probability such that more quantitative treatment of the temporal development of erosion is necessary to arrive at meaningful probabilities of failure. This report builds upon the current state of the practice by investigating BEP progression rates through a series of laboratory experiments. BEP progression rates were measured for nine uniform sands in a series of 55 small-scale flume tests. Results indicate that the pipe progression rates are proportional to the seepage velocity and can be predicted using equations recently proposed in the literature.

  • Synthesis and Characterization of Biological Nanomaterial/Poly(vinylidene fluoride) Composites

    Abstract: The properties of composite materials are strongly influenced by both the physical and chemical properties of their individual constituents, as well as the interactions between them. For nanocomposites, the incorporation of nano-sized dopants inside a host material matrix can lead to significant improvements in mechanical strength, toughness, thermal or electrical conductivity, etc. In this work, the effect of cellulose nanofibrils on the structure and mechanical properties of cellulose nanofibril poly(vinylidene fluoride) (PVDF) composite films was investigated. Cellulose is one of the most abundant organic polymers with superior mechanical properties and readily functionalized surfaces. Under the current processing conditions, cellulose nanofibrils, as-received and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidized, alter the crystallinity and mechanical properties of the composite films while not inducing a crystalline phase transformation on the 𝛾 phase PVDF composites. Composite films obtained from hydrated cellulose nanofibrils remain in a majority 𝛾 phase, but also exhibit a small, yet detectable fraction of 𝛼 and ß PVDF phases.

  • CuO Enhances the Photocatalytic Activity of Fe₂O₃ through Synergistic Reactive Oxygen Species Interactions

    Abstract: Iron oxide (α-Fe2O3, hematite) colloids were synthesized under hydrothermal conditions and investigated as catalysts for the photodegradation of an organic dye under broad-spectrum illumination. To enhance photocatalytic performance, Fe2O3 was combined with other transition-metal oxide (TMO) colloids (e.g., CuO and ZnO), which are sensitive to different regions of the solar spectrum (far visible and ultraviolet, respectively), using a ternary blending approach for compositional mixtures. For a variety of ZnO/Fe2O3/CuO mole ratios, the pseudo-first-order rate constant for methyl orange degradation was at least double the sum of the individual Fe2O3 and CuO rate constants, indicating there is an underlying synergy governing the photocatalysis reaction with these combinations of TMOs. A full compositional study was carried out to map the interactions between the three TMOs. Additional experiments probed the identity and role of reactive oxygen species and elucidated the mechanism by which CuO enhanced Fe2O3 photodegradation while ZnO did not. The increased photocatalytic performance of Fe2O3 in the presence of CuO was associated with hydroxyl radical ROS, consistent with heterogeneous photo-Fenton mechanisms, which are not accessible by ZnO. These results imply that low-cost photocatalytic materials can be engineered for high performance under solar illumination by selective pairing of TMOs with compatible ROS.

  • Estimating Growing-Season Root Zone Soil Moisture from Vegetation Index-Based Evapotranspiration Fraction and Soil Properties in the Northwest Mountain Region, USA

    Abstract: A soil moisture retrieval method is proposed, in the absence of ground-based auxiliary measurements, by deriving the soil moisture content relationship from the satellite vegetation index-based evapotranspiration fraction and soil moisture physical properties of a soil type. A temperature–vegetation dryness index threshold value is also proposed to identify water bodies and underlying saturated areas. Verification of the retrieved growing season soil moisture was performed by comparative analysis of soil moisture obtained by observed conventional in situ point measurements at the 239-km2 Reynolds Creek Experimental Watershed, Idaho, USA (2006–2009), and at the US Climate Reference Network (USCRN) soil moisture measurement sites in Sundance, Wyoming (2012–2015), and Lewistown, Montana (2014–2015). The proposed method best represented the effective root zone soil moisture condition, at a depth between 50 and 100 cm, with an overall average R2 value of 0.72 and average root mean square error (RMSE) of 0.042.