64 research outputs found
Applying the Submerged Jet Erosion Test to Embankment Dam Breach Modeling
The submerged jet erosion test (JET) is one of several methods available for quantifying erodibility of cohesive soils, a crucial input for modeling erosion and breach of embankment dams with models such as WinDAM, EMBREA (Morris 2011), and DL BREACH (Wu 2013; 2016a; 2016b). The JET was initially developed in the late 1980s as a relatively large-scale device with a 13-mm diameter nozzle creating an impinging jet that erodes a soil sample submerged in a 61-cm diameter tank. This first device was documented in an ASTM standard (D5852-1995), but the standard was withdrawn in 2016. In the last 15 to 20 years, smaller scale devices have become common, including one described as the “original JET” (6.4-mm nozzle operating within a 30.5-cm tank) (Hanson and Cook 2004) and the newer “mini-JET” (3 mm nozzle and 10-cm tank) (Al-Madhhachi et al. 2013b). New methods for analyzing the scour-vs.-time data obtained from the JET have also been proposed, some (Daly et al. 2013) based on the traditional linear excess stress equation describing the soil etachment process, and others (Al-Madhhachi et al. 2013a) based on nonlinear soil erosion models such as the mechanistic Wilson model (Wilson 1993a, 1993b). This paper provides an overview of JET history and development and then summarizes a recent study (Wahl 2021) comparing JET data analysis methods. Fifty-two JET experiments on four different soil types (lean clay, silty clay, clayey sand, and silty sand) were analyzed by nine different methods. The results give indications of the practical value of linear vs. nonlinear soil erosion models and the effectiveness of different curve-fitting methods for estimating erodibility parameters. Suggestions for the use of the JET in dam breach modeling are offered
Failure Thresholds for RCC Crest Caps
Overtopping protection using roller-compacted concrete (RCC) overlays is a common improvement made to address hydrologic deficiencies at existing small- to medium-height embankment dams. Overlays allow floods to pass over the dam while preventing erosion of the original embankment. The United States has many examples of such projects on both private and public dams, including many associated with federal agencies of the Departments of the Interior and Agriculture. For one project modified with an overlay in 1993, deterioration of the RCC and poor bonding between lifts has caused concern for stability of the 0.3-m (1-ft) thick RCC lifts that cap the dam. Analytical studies from 2013 to the present have assessed potential failure modes during overtopping flow and have produced widely varying estimates of the probability of failure. To address this uncertainty, physical scale modeling in the Bureau of Reclamation Hydraulics Laboratory was used to evaluate crest cap failure modes for the conservative condition of unbonded RCC lifts. The testing defines the threshold conditions for failure, which will enable effective evaluation of risk for similar facilities in the future
Hydraulic Computations for Stepped Concrete Overlays of Embankment Dams
One method for rehabilitating and modernizing embankment dams is the addition of a concrete overlay that protects the embankment and allows floods to pass safely over the dam. Roller compacted concrete is commonly used, which makes it practical to use a stepped construction that also enhances energy dissipation. Analysis of flow conditions over such structures requires computation of aerated flow and its effects on flow depth, training wall design, and energy dissipation. This paper describes Spillway Pro, an energy-based water surface profile calculation tool for smooth spillway chutes (Wahl et al. 2019), recently improved to also analyze stepped chutes. The tool is applicable to a wide range of chute slopes, including flatter slopes typical of embankment dam overlays and steeper slopes encountered on concrete gravity dams. An energy-based analysis allows Spillway Pro to be applied to situations differing from the idealized configurations covered by available empirical approaches, such as non-constant slopes, varying step heights, and converging chutes. Spillway Pro integrates water surface profile calculations, aerated flow effects, and cavitation analysis, which is potentially important for steeper slopes and large unit discharges. Simultaneous calculation of smooth and stepped-chute flow profiles enables rapid assessment of the energy dissipation benefits of steps, as well as a comparison of the aerated flow and cavitation issues for smooth vs. stepped chute alternatives
Flumes and weirs
Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Long-throated flumes and broad-crested weirs provide a practical, low-cost, flexible means of measuring open-channel flows in new and existing irrigation systems and have distinct advantages over other flume and weir devices. Application of these flumes and weirs has been greatly facilitated by the 1999 release of the WinFlume software used to design and calibrate these structures, and the recent publication of Water Measurement with Flumes and Weirs, a text providing comprehensive information on design, calibration, construction, and operation issues. The primary advantages of these flumes and weirs are that they can be custom-designed to satisfy unique operational and site requirements, and they can be computer calibrated without the need for laboratory testing. In addition, these devices are easily and economically constructed, and a number of commercially built, pre-calibrated devices are available. This paper and accompanying poster describe the use of the WinFlume software and present examples to illustrate application to a range of situations, including various flow rates, channel types, and construction techniques
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Imaging biomarker roadmap for cancer studies.
Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution
2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.
Correction to: 2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales. Archives of Virology (2021) 166:3567–3579. https://doi.org/10.1007/s00705-021-05266-wIn March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.This work was supported in part through Laulima Government Solutions, LLC prime contract with the US National Institute of Allergy and Infectious Diseases (NIAID) under Contract No. HHSN272201800013C. J.H.K. performed this work as an employee of Tunnell Government Services (TGS), a subcontractor of Laulima Government Solutions, LLC under Contract No. HHSN272201800013C. This work was also supported in part with federal funds from the National Cancer Institute (NCI), National Institutes of Health (NIH), under Contract No. 75N91019D00024, Task Order No. 75N91019F00130 to I.C., who was supported by the Clinical Monitoring Research Program Directorate, Frederick National Lab for Cancer Research. This work was also funded in part by Contract No. HSHQDC-15-C-00064 awarded by DHS S&T for the management and operation of The National Biodefense Analysis and Countermeasures Center, a federally funded research and development center operated by the Battelle National Biodefense Institute (V.W.); and NIH contract HHSN272201000040I/HHSN27200004/D04 and grant R24AI120942 (N.V., R.B.T.). S.S. acknowledges partial support from the Special Research Initiative of Mississippi Agricultural and Forestry Experiment Station (MAFES), Mississippi State University, and the National Institute of Food and Agriculture, US Department of Agriculture, Hatch Project 1021494. Part of this work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001030), the UK Medical Research Council (FC001030), and the Wellcome Trust (FC001030).S
Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry
OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc).
METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers.
RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group.
CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies
2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.
In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV
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