21 research outputs found

    Spectro-interferometric observations of classical nova V458 Vul 2007

    Full text link
    We used the Palomar Testbed Interferometer (PTI) to resolve 2.2 μ\mum emission from the classical nova V458 Vul 2007 over the course of several days following its discovery on 2007 August 8.54 UT. We also obtained K-band photometric data and spectra of the nova during the early days of the outburst. We also used photometric measurements from the AAVSO database. This is a unique data set offering a 3-technique approach: high-resolution imaging, spectroscopy and photometry. Our analysis shows that the nova ejecta can be modeled as an inclined disk at low inclination i.e. low ellipticity which is consistent with the nova being in the fireball phase at which the outflowing gas is optically thick, confirmed by the presence of strong P-Cygni Balmer lines in the spectra. The expansion velocity is \approx1700 km s1\rm km\ s^{-1}, derived from the Hα\alpha line. By combining the nova's angular expansion rate measured by PTI with the expansion rate measured from spectroscopy, the inferred distance to the nova is 9.9-11.4 kpc. We also used the K-band fluxes and the derived size of the emission to estimate the total mass ejected from the nova 4×104M\approx 4\times 10^{-4} M_{\odot}. The quick transition of the nova from Fe II to He/N class makes V458 Vul 2007 a hybrid nova.Comment: 31 pages, 7 figures, accepted for publication in Ap

    How High to Fly? Mapping Evapotranspiration from Remotely Piloted Aircrafts at Different Elevations

    No full text
    Recent advancements in remotely piloted aircrafts (RPAs) have made frequent, low-flying imagery collection more economical and feasible than ever before. The goal of this work was to create, compare, and quantify uncertainty associated with evapotranspiration (ET) maps generated from different conditions and image capture elevations. We collected optical and thermal data from a commercially irrigated potato (Solanum tuberosum) field in the Wisconsin Central Sands using a quadcopter RPA system and combined multispectral/thermal camera. We conducted eight mission sets (24 total missions) during the 2019 growing season. Each mission set included flights at 90, 60, and 30 m above ground level. Ground reference measurements of surface temperature and soil moisture were collected throughout the domain within 15 min of each RPA mission set. Evapotranspiration values were modeled from the flight data using the High-Resolution Mapping of Evapotranspiration (HRMET) model. We compared HRMET-derived ET estimates to an Eddy Covariance system within the flight domain. Additionally, we assessed uncertainty for each flight using a Monte Carlo approach. Results indicate that the primary source of uncertainty in ET estimates was the optical and thermal data. Despite some additional detectable features at low elevation, we conclude that the tradeoff in resources and computation does not currently justify low elevation flights for annual vegetable crop management in the Midwest USA

    How High to Fly? Mapping Evapotranspiration from Remotely Piloted Aircrafts at Different Elevations

    No full text
    Recent advancements in remotely piloted aircrafts (RPAs) have made frequent, low-flying imagery collection more economical and feasible than ever before. The goal of this work was to create, compare, and quantify uncertainty associated with evapotranspiration (ET) maps generated from different conditions and image capture elevations. We collected optical and thermal data from a commercially irrigated potato (Solanum tuberosum) field in the Wisconsin Central Sands using a quadcopter RPA system and combined multispectral/thermal camera. We conducted eight mission sets (24 total missions) during the 2019 growing season. Each mission set included flights at 90, 60, and 30 m above ground level. Ground reference measurements of surface temperature and soil moisture were collected throughout the domain within 15 min of each RPA mission set. Evapotranspiration values were modeled from the flight data using the High-Resolution Mapping of Evapotranspiration (HRMET) model. We compared HRMET-derived ET estimates to an Eddy Covariance system within the flight domain. Additionally, we assessed uncertainty for each flight using a Monte Carlo approach. Results indicate that the primary source of uncertainty in ET estimates was the optical and thermal data. Despite some additional detectable features at low elevation, we conclude that the tradeoff in resources and computation does not currently justify low elevation flights for annual vegetable crop management in the Midwest USA

    Measuring Tsunami Planning Capacity on U.S. Pacific Coast

    Get PDF
    Abstract: The U.S. Pacific coastal states are at risk from both locally and distantly generated tsunamis. This vulnerability can be reduced by effective hazard management plans, but no studies have been conducted to determine how local jurisdictions have incorporated tsunami hazard management into their planning frameworks. This paper analyzes the quality of hazard management plans from 43 coastal counties in these states. Plan quality was measured by a plan evaluation protocol defined by five components and 37 indicators. The results show that few Pacific coastal counties have prepared well for tsunamis. Most plans have a weak factual basis, unclear goals and objectives, weak policies, and few coordination and implementation mechanisms. The average plan quality score is 12.25 out of 50 points and 10 counties never mention tsunami risks in their local plans at all. This evaluation suggests that these jurisdictions need to build a solid factual basis about tsunami hazards, set appropriate goals and practical objectives, expand the array of tools used by planners, enhance interdisciplinary and interorganizational coordination mechanisms, and improve their mechanisms for plan implementation

    Limitations of Available Blood Products for Massive Transfusion During Mass Casualty Events at US Level 1 Trauma Centers

    No full text
    Introduction: Exsanguination remains a leading cause of preventable death in traumatically injured patients. To better treat hemorrhagic shock, hospitals have adopted massive transfusion protocols (MTPs) which accelerate the delivery of blood products to patients. There has been an increase in mass casualty events (MCE) worldwide over the past two decades. These events can overwhelm a responding hospitals supply of blood products. Using a computerized model, this study investigated the ability of US trauma centers (TCs) to meet the blood product requirements of MCEs. Methods: Cross-sectional survey data of on-hand blood products were collected from 16 US level-1 TCs. A discrete event simulation model of a TC was developed based on historic data of blood product consumption during MCEs. Each hospitals blood bank was evaluated across increasingly more demanding MCEs using modern MTPs to guide resuscitation efforts in massive transfusion (MT) patients. Results: A total of 9,000 simulations were performed on each TCs data. Under the least demanding MCE scenario, the median size MCE in which TCs failed to adequately meet blood product demand was 50 patients (IQR 20-90), considering platelets. Ten TCs exhaust their supply of platelets prior to red blood cells (RBCs) or plasma. Disregarding platelets, five TCs exhausted their supply of O- packed RBCs, six exhausted their AB plasma supply, and five had a mixed exhaustion picture. Conclusion: Assuming a TCs ability to treat patients is limited only by their supply of blood products, US level-1 TCs lack the on-hand blood products required to adequately treat patients following a MCE. Use of non-traditional blood products, which have a longer shelf life, may allow TCs to better meet the blood product requirement needs of patients following larger MCEs.Funding Agencies|Center for Translational Injury Research; John B Holmes Professorship in Clinical Sciences</p

    Limitations of Available Blood Products for Massive Transfusion During Mass Casualty Events at us Level 1 Trauma Centers

    No full text
    Introduction: Exsanguination remains a leading cause of preventable death in traumatically injured patients. To better treat hemorrhagic shock, hospitals have adopted massive transfusion protocols (MTPs) which accelerate the delivery of blood products to patients. There has been an increase in mass casualty events (MCE) worldwide over the past two decades. These events can overwhelm a responding hospitals supply of blood products. Using a computerized model, this study investigated the ability of US trauma centers (TCs) to meet the blood product requirements of MCEs. Methods: Cross-sectional survey data of on-hand blood products were collected from 16 US level-1 TCs. A discrete event simulation model of a TC was developed based on historic data of blood product consumption during MCEs. Each hospitals blood bank was evaluated across increasingly more demanding MCEs using modern MTPs to guide resuscitation efforts in massive transfusion (MT) patients. Results: A total of 9,000 simulations were performed on each TCs data. Under the least demanding MCE scenario, the median size MCE in which TCs failed to adequately meet blood product demand was 50 patients (IQR 20-90), considering platelets. Ten TCs exhaust their supply of platelets prior to red blood cells (RBCs) or plasma. Disregarding platelets, five TCs exhausted their supply of O- packed RBCs, six exhausted their AB plasma supply, and five had a mixed exhaustion picture. Conclusion: Assuming a TCs ability to treat patients is limited only by their supply of blood products, US level-1 TCs lack the on-hand blood products required to adequately treat patients following a MCE. Use of non-traditional blood products, which have a longer shelf life, may allow TCs to better meet the blood product requirement needs of patients following larger MCEs.Funding Agencies|Center for Translational Injury Research; John B Holmes Professorship in Clinical Sciences</p
    corecore