1,083 research outputs found
Characteristics of flow in trapezoidal and triangular irrigation furrows
This bulletin is a report on Department of Agricultural Engineering research project 395, 'Use of Water'. Work was done in cooperation with the Corn Belt Branch, Soil and Water Conservation Research Division, Agricultural Research Service, USDA--P. [3].Digitized 2007 AES.Includes bibliographical references (page 27)
Imaging of adult ocular and orbital pathology - a pictorial review
Orbital pathology often presents a diagnostic challenge to the reporting radiologist. The aetiology is protean, and clinical input is therefore often necessary to narrow the differential diagnosis. With this manuscript, we provide a pictorial review of adult ocular and orbital pathology.peer-reviewe
Energy input is primary controller of methane bubbling in subarctic lakes
Emission of methane (CH4) from surface waters is often dominated by ebullition (bubbling), a transport mode with high‐spatiotemporal variability. Based on new and extensive CH4 ebullition data, we demonstrate striking correlations (r2 between 0.92 and 0.997) when comparing seasonal bubble CH4 flux from three shallow subarctic lakes to four readily measurable proxies of incoming energy flux and daily flux magnitudes to surface sediment temperature (r2 between 0.86 and 0.94). Our results after continuous multiyear sampling suggest that CH4 ebullition is a predictable process, and that heat flux into the lakes is the dominant driver of gas production and release. Future changes in the energy received by lakes and ponds due to shorter ice‐covered seasons will predictably alter the ebullitive CH4 flux from freshwater systems across northern landscapes. This finding is critical for our understanding of the dynamics of radiatively important trace gas sources and associated climate feedback
Fortnightly tides and subtidal motions in a choked inlet
This paper is not subject to U.S. copyright. The definitive version was published in Estuarine, Coastal and Shelf Science 150, Pt.B (2014): 325-331, doi:10.1016/j.ecss.2014.03.025.Amplitudes of semi-diurnal tidal fluctuations measured at an ocean inlet system decay nearly linearly by 87% between the ocean edge of the offshore ebb-tidal delta and the backbay. A monochromatic, dynamical model for a tidally choked inlet separately reproduces the evolution of the amplitudes and phases of the semi-diurnal and diurnal tidal constituents observed between the ocean and inland locations. However, the monochromatic model over-predicts the amplitude and under-predicts the lag of the lower-frequency subtidal and fortnightly motions observed in the backbay. A dimensional model that considers all tidal constituents simultaneously, balances the along-channel pressure gradient with quadratic bottom friction, and that includes a time-varying channel water depth, is used to show that that these model-data differences are associated with nonlinear interactions between the tidal constituents that are not included in non-dimensional, monochromatic models. In particular, numerical simulations suggest that the nonlinear interactions induced by quadratic bottom friction modify the amplitude and phase of the subtidal and fortnightly backbay response. This nonlinear effect on the low-frequency (subtidal and fortnightly) motions increases with increasing high-frequency (semi-diurnal) amplitude. The subtidal and fortnightly motions influence water exchange processes, and thus backbay temperature and salinity.We thank the Office of Naval Research (N0001411WX20962; N0001412WX20498) for funding
Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States
Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004), SENEX (June–July 2013), and SEAC4RS (August–September 2013) and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (∼ 42–45%), followed by NOx (31%), total peroxy nitrates (ΣPNs; 14%), and total alkyl nitrates (ΣANs; 9–12%) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOxemissions will lead to a continued decline in surface ozone and less frequent high-ozone events
Surgical smoke evacuation device implementation: a quality improvement project at Doernbecher Children’s Hospital
Surgical smoke, created via energy-generating surgical devices, is a physical, chemical, and biological hazard that adversely affects the health of exposed individuals. Smoke evacuation devices (SEDs) are readily available at Doernbecher Children’s Hospital (DCH), though a 2020 gap analysis showed they are used in only 3.2% of annual smoke-generating cases. Surgical smoke evacuation legislation was introduced January 1, 2023, in Oregon, requiring hospitals and ambulatory surgery centers to prevent surgical smoke exposure in ORs. The goal of this quality improvement (QI) was to quantify the use of and track compliance of surgical smoke evacuation, while helping the facility to attain the AORN Go Clear recognition. This QI project relied on Duke University’s FADE methodology to achieve the goal. Based on supply utilization, SEDs were utilized infrequently (4.06%) during the period of Covid when surgical smoke initiatives were paused, increased to 13.88% when surgical smoke awareness and education were reinstated, and spiked to 47.65% with Go Clear audits and institution of legislation for surgical smoke evacuation. A 95% compliance rate for surgical smoke evacuation (SED and non-SED devices) allowed the site to be awarded the AORN Go Clear designation. This project supports the use of multiple interventions including surgical smoke awareness and education, equipment-related factors, and policy/regulation changes to successfully implement the use of smoke evacuation devices in ORs
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