38,532 research outputs found

    High reliability cathode heaters for ion thrusters

    Get PDF
    A number of space missions were proposed which utilize 30-cm mercury bombardment ion thrusters and also require a large number of thruster restarts. A test program was carried out to determine thermal cycle life of several different cathode heater designs. Plasma/flame sprayed heaters and swaged type heaters were tested. Four of the five plasma/flame sprayed heaters tested failed in a comparatively short time. Four tantalum swaged heaters that were brazed to the tantalum cathode tube were successfully tested and met the goals that were set at the start of the test

    Physician documentation of access to firearms in suicidal patients in the emergency department

    Get PDF
    Introduction: Suicide is the 10th leading cause of death in the United States. An estimated 50% of these deaths are due to firearms. Suicidal ideation (SI) is a common complaint presenting to the emergency department (ED). Despite these facts, provider documentation on access to lethal means is lacking. Our primary aim was to quantify documentation of access to firearms in patients presenting to the ED with a chief complaint of SI.Methods: This was a cross-sectional study of consecutive patients, nearly all of whom presented to an academic, urban ED with SI during July 2014. We collected data from all provider documentation in the electronic health record. Primary outcome assessed was whether the emergency physician (EP) team documented access to firearms. Secondary outcomes included demographic information, preexisting psychiatric diagnoses, and disposition.Results: We reviewed 100 patient charts. The median age of patients was 38 years. The majority of patients had a psychiatric condition. EPs documented access to firearms in only 3% of patient charts.Conclusion: EPs do not adequately document access to firearms in patients with SI. There is a clear need for educational initiatives regarding risk-factor assessment and counseling against lethal means in this patient cohort

    Solar array strip and a method for forming the same

    Get PDF
    A flexible solar array strip is formed by providing printed circuitry between flexible layers of a nonconductive material, depositing solder pads on the printed circuitry, and storing the resulting substrate on a drum from which it is then withdrawn and advanced along a linear path. Solderless solar cells are serially transported into engagement with the pads and are infrared radiation to melt the solder and attach the cells to the circuitry. Excess flux is cleaned from the solar cells which are then encapsulated in a protective coating. The resulting array is then wound on a drum

    Hydrogen maser for field use Technical report, Jun. 27, 1966 - Jan. 30, 1968

    Get PDF
    Hydrogen maser for field use with cavity and bulb design of maser for satellite application

    Direct EIT Reconstructions of Complex Admittivities on a Chest-Shaped Domain in 2-D

    Get PDF
    Electrical impedance tomography (EIT) is a medical imaging technique in which current is applied on electrodes on the surface of the body, the resulting voltage is measured, and an inverse problem is solved to recover the conductivity and/or permittivity in the interior. Images are then formed from the reconstructed conductivity and permittivity distributions. In the 2-D geometry, EIT is clinically useful for chest imaging. In this work, an implementation of a D-bar method for complex admittivities on a general 2-D domain is presented. In particular, reconstructions are computed on a chest-shaped domain for several realistic phantoms including a simulated pneumothorax, hyperinflation, and pleural effusion. The method demonstrates robustness in the presence of noise. Reconstructions from trigonometric and pairwise current injection patterns are included
    corecore