552 research outputs found

    Feasibility Study of Thermal Treatment for Mercury Removal from Soils

    Get PDF
    Thermal remediation is an established method for the remediation of volatile organic compounds (VOCs). Thermal remediation for the remediation of elemental mercury was successfully applied by Kunkel et al., 2006 in the laboratory scale. Before the technology can be applied to the field scale, the thermal treatment for mercury needs to better understood using numerical simulation. The Department of Energy’s TOUGH2/TMVOC Code was developed at the Lawrence Berkeley National Laboratory and was used to evaluate the potential effectiveness of thermal treatment to remediate elemental mercury. TMVOC is a three phase non-isothermal numerical simulator for water, gas, and VOCs in porous media and was used to simulate the removal of elemental mercury due to its liquid state at 25°C and relatively high vapor pressure at elevated temperatures. The overlying work was conducted as feasibility research for the maturation of thermal treatment for elemental mercury. Multiphase flow, contaminant phase change, and transport processes were investigated as mercury transfers from the liquid to gas phase and is then extracted from the system. Geometry, temperature, pressure and mass injection rates were evaluated to better understand the thermal treatment process for the treatment of mercury. The study consists of three key elements: 1) Numerical simulation of one dimensional thermal treatment experiments performed by Kunkel et al., 2006 for the treatment of elemental mercury 2) Simulation of ex-situ thermal treatment simulation under varying conditions for the removal of elemental mercury and 3) A feasibility assessment of in-situ thermal treatment for the removal of elemental mercury in porous media

    Accurately monitoring the Florida Current with motionally induced voltages

    Get PDF
    A new experimental technique for appraising how accurately submarine-cable (subcable) voltages monitor oceanic volume transport is presented and then used to study voltages induced by the northern Florida Current. Until recently, subcable voltages have been largely dismissed as an oceanographic tool because their interpretation can be ambiguous. They depend upon the transport field, the electrical conductance of the environment, and the mutual spatial distribution of these two quantities. To examine how these three factors affect subcable voltages at a particular site, we combine data from two different velocity profilers: XCP and PEGASUS. These instruments provide vertical profiles of velocity, temperature, and motion ally induced voltage at several sites across a transect. From this information, we determine if and why subcable voltages track volume transport. We conclude that subcable voltages measured in the northern Florida Straits accurately monitor the Florida Current transport because they are insensitive to the spatial distribution of the flow—a result that stems from a large and rather uniform seabed conductance. Subcable voltages should be reconsidered for oceanic monitoring elsewhere because the validity of their interpretation can now be assessed

    High Sensitivity DNA Detection Using Gold Nanoparticle Functionalised Polyaniline Nanofibres

    Get PDF
    Polyaniline (PANI) nanofibres (PANI-NF) have been modified with chemically grown gold nanoparticles to give a nanocomposite material (PANI-NF–AuNP) and deposited on gold electrodes. Single stranded capture DNA was then bound to the gold nanoparticles and the underlying gold electrode and allowed to hybridise with a complementary target strand that is uniquely associated with the pathogen, Staphylococcus aureus (S. aureus), that causes mastitis. Significantly, cyclic voltammetry demonstrates that deposition of the gold nanoparticles increases the area available for DNA immobilisation by a factor of approximately 4. EPR reveals that the addition of the Au nanoparticles efficiently decreases the interactions between adjacent PANI chains and/or motional broadening. Finally, a second horseradish peroxidase (HRP) labelled DNA strand hybridises with the target allowing the concentration of the target DNA to be detected by monitoring the reduction of a hydroquinone mediator in solution. The sensors have a wide dynamic range, excellent ability to discriminate DNA mismatches and a high sensitivity. Semi-log plots of the pathogen DNA concentration vs. faradaic current were linear from 150 × 10−12 to 1 × 10−6 mol L−1 and pM concentrations could be detected without the need for molecular, e.g., PCR or NASBA, amplification

    Application of unsteady aeroelastic analysis techniques on the national aerospace plane

    Get PDF
    A presentation provided at the Fourth National Aerospace Plane Technology Symposium held in Monterey, California, in February 1988 is discussed. The objective is to provide current results of ongoing investigations to develop a methodology for predicting the aerothermoelastic characteristics of NASP-type (hypersonic) flight vehicles. Several existing subsonic and supersonic unsteady aerodynamic codes applicable to the hypersonic class of flight vehicles that are generally available to the aerospace industry are described. These codes were evaluated by comparing calculated results with measured wind-tunnel aeroelastic data. The agreement was quite good in the subsonic speed range but showed mixed agreement in the supersonic range. In addition, a future endeavor to extend the aeroelastic analysis capability to hypersonic speeds is outlined. An investigation to identify the critical parameters affecting the aeroelastic characteristics of a hypersonic vehicle, to define and understand the various flutter mechanisms, and to develop trends for the important parameters using a simplified finite element model of the vehicle is summarized. This study showed the value of performing inexpensive and timely aeroelastic wind-tunnel tests to expand the experimental data base required for code validation using simple to complex models that are representative of the NASP configurations and root boundary conditions are discussed

    Aerothermoelastic analysis of a NASP demonstrator model

    Get PDF
    The proposed National Aerospace Plane (NASP) is designed to travel at speeds up to Mach 25. Because aerodynamic heating during high-speed flight through the atmosphere could destiffen a structure, significant couplings between the elastic and rigid body modes could result in lower flutter speeds and more pronounced aeroelastic response characteristics. These speeds will also generate thermal loads on the structure. The purpose of this research is to develop methodologies applicable to the NASP and to apply them to a representative model to determine its aerothermoelastic characteristics when subjected to these thermal loads. This paper describes an aerothermoelastic analysis of the generic hypersonic vehicle configuration. The steps involved in this analysis were: generating vehicle surface temperatures at the appropriate flight conditions; applying these temperatures to the vehicle's structure to predict changes in the stiffness resulting from material property degradation; predicting the vibration characteristics of the heated structure at the various temperature conditions; performing aerodynamic analyses; and conducting flutter analysis of the heated vehicle. Results of these analyses and conclusions representative of a NASP vehicle are provided in this paper

    The Grizzly, November 9, 2017

    Get PDF
    Department of Education Rolls Back Piece of Title IX • Joe DeSimone \u2786 Receives Heinz Award • New Education Major Created • Nadler Awarded Tow Fellowship • Dr. Kerr Appears on Full Frontal with Samantha Bee • History of a Historian • Opinions: Male Gun Violence Must End with Restrictive Gun Legislation; JFK\u27s Legacy Should be More Than Assassination Conspiracies • Senior Athletes Share Memories as Fall Sports Seasons Wind to a Close • Football Drops Three of Last Four Gameshttps://digitalcommons.ursinus.edu/grizzlynews/1631/thumbnail.jp

    715-2 A Prospective, Randomized Trial Evaluating the Prophylactic Use of Balloon Pumping in High Risk Myocardial Infarction Patients: PAMI-2

    Get PDF
    Myocardial infarction (MI) patients with advanced age, multivessel disease or ventricular dysfunction continue to have a poor prognosis despite reperfusion therapy. Furthermore, the majority of deaths from MI occur within the first 48 hours, thus risk stratification and therapeutic interventions ideally should occur acutely. The PAMI-2 study has prospectively evaluated the hypotheses that 1) emergency catheterization with primary PTCA may allow acute risk stratification and 2) clinical outcome, ventricular function and infarct vessel patency will be improved by balloon pumping in patients identified to be high risk. MI patients who presented 0–12 hrs underwent emergency catheterization and PTCA and were stratified as high risk if one of the following was present: age>70 yrs, vein graft occlusion, 3 vessel disease, ejection fraction <45%, suboptimal PTCA result or if malignant arrhythmias persisted post PTCA. High risk patients were randomized to receive or not receive an intra aortic balloon pump (IABP) for 48 hrs. Catheterization was repeated at day 7 to determine infarct vessel patency and improvement in ventricular function. At 6 weeks a rest and exercise radionuclide ventriculogram was performed. To date, 320 patients have been enrolled, 175 of which have complete data available for analysis. The reasons for high risk status include: advanced age 38%, poor LV function 55%, 3 vessel disease 37%, vein graft occlusion 6%, suboptimal PTCA 9%, and arrhythmias 5%. Despite the high risk status, in-hospital outcomes have been favorable: death 2.9%, recurrent MI 5.8%, stroke 1.2%, angiographic reocclusion 5.8%, heart failure 19.1% and combined events 26.6%. Thus “high risk” patients treated with primary PTCA±balloon pumping appear to have a good prognosis. Whether the improved outcome is due to balloon pump support or simply due to aggressive mechanical revascularization will be determined in the entire cohort by March 1995

    Experimental Results from the Active Aeroelastic Wing Wind Tunnel Test Program

    Get PDF
    The Active Aeroelastic Wing (AAW) program is a cooperative effort among NASA, the Air Force Research Laboratory and the Boeing Company, encompassing flight testing, wind tunnel testing and analyses. The objective of the AAW program is to investigate the improvements that can be realized by exploiting aeroelastic characteristics, rather than viewing them as a detriment to vehicle performance and stability. To meet this objective, a wind tunnel model was crafted to duplicate the static aeroelastic behavior of the AAW flight vehicle. The model was tested in the NASA Langley Transonic Dynamics Tunnel in July and August 2004. The wind tunnel investigation served the program goal in three ways. First, the wind tunnel provided a benchmark for comparison with the flight vehicle and various levels of theoretical analyses. Second, it provided detailed insight highlighting the effects of individual parameters upon the aeroelastic response of the AAW vehicle. This parameter identification can then be used for future aeroelastic vehicle design guidance. Third, it provided data to validate scaling laws and their applicability with respect to statically scaled aeroelastic models
    corecore