4,429 research outputs found

    Coexisting Cardiac and Hematologic Disorders.

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    Patients with concomitant cardiac and hematologic disorders presenting for noncardiac surgery are challenging. Anemic patients with cardiac disease should be approached in a methodical fashion. Transfusion triggers and target should be based on underlying symptomatology. The approach to anticoagulation management in patients with artificial heart valves, cardiac devices, or severe heart failure in the operative setting must encompass a complete understanding of the rationale of a patient\u27s therapy as well as calculate the risk of changing this regimen. This article focuses common disorders and discusses strategies to optimize care in patients with coexisting cardiac and hematologic disease

    Fabrication and testing of negative-limited sealed nickel-cadmium cells

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    The design, construction, and testing of 100,20Ah and 100,3Ah negative-limited sealed cells are reported. The required physical dimensions of the hardware and components necessary to produce 20 and 3 Ah cells were established. The stainless steel cans and covers have been ordered. The covers contain two ceramic seals. The fabrication of electrodes was started. About 55% (879 electrodes) of the required cadmium electrodes has been prepared. About 44% of the porous nickel substrates (plaques) required for the preparation of the nickel oxide electrodes has been completed

    Preliminary evaluation of the role of K2S in MHD hot stream seed recovery

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    Results are presented for recent analytical and experimental studies of the role of K2S in MHD hot stream seed recovery. The existing thermodynamic data base was found to contain large uncertainties and to be nonexistent for vapor phase K2S. Knudsen cell mass spectrometric experiments were undertaken to determine the vapor species in equilibrium with K2S(c). K atoms and S2 molecules ere found to be the major vapor phase species in vacuum, accounting for greater than 99 percent of the vapor phase. Combustion gas deposition studies using No. 2 Diesel fuel were also undertaken and revealed that condensed phase K2SO3 may potentially be an important compound in the MHD stream at near-stoichiometric combustion

    Maternal Health Workforce Shortages in Southeast Pennsylvania

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    Since 1997, 19 maternity wards have closed in Southeastern Pennsylvania, leaving only 23 to serve the women and families in the area. Additionally, there have been reports of maternal health workforce shortages, causing many women difficulty in accessing the care they need. This aims of this qualitative study were to define the problem of maternal health workforce shortages in the region and to identify potential solutions. Ten key stakeholders were identified for participation. A single researcher conducted interviews using a structured interview guide. Results were analyzed for content and major themes by two researchers. The eight sections include: 1. preconception counseling and postpartum care, 2. prenatal care, 3. post-partum care, 4. workforce development and retention, 5. defining shortages and implications, 6. understanding shortages, 7. approaching solutions and 8. stakeholders and problem-solvers. This study confirmed that there are workforce shortages, and that root causes are multi-factorial, with system, provider, and patient levels. Potential solutions include tort reform, improving structural relationships, increasing interdisciplinary collaboration, improving communication, and raising community awareness. Such efforts will require collaboration among multiple stakeholder groups, most notable patients and providers

    Utilizing an Individually Built Mobile Robot in the Laboratory of an Advanced Digital Logic Design Course in Conjunction with a Final Class Competition

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    This paper describes the development and implementation of a series of laboratory projects utilized in a junior level, required course for computer engineering majors titled, “Advanced Digital Logic Design.” Eleven of the 13 lab experiences are directly related to this project. The first five labs are mainly construction labs where students are developing practical hands-on skills and gaining familiarity with common prototyping practices. These skills include (a) utilizing a 3-D printer in order to create the chassis, wheels, and sensor mounts, (b) disassembly, modification, and reassembly of two servo motors, and (c) assembly and soldering two custom-designed printed circuit boards (PCB) totaling approximately 50 components and 200 solder points. Once the all the subsystems are complete, then they are screwed together, along with a battery pack and front contact sensing bumper. In the final six labs, the students systematically build-up the various digital designs needed in order to autonomously control their individually built mobile robot. These labs include digital designs (a) to control the servos, (b) to play an accurate song on a small speaker, (c) to communicate with five infrared (IR) distance sensors in order to obtain range information, (d) to create a complex finite state machine (FSM), and (e) to control the overall behavior of the robot. A 240 logic cell Complex Programmable Logic Device (CPLD) limits each student’s design space and, consequently, efficiency of implementations is enforced. Milestones are graded throughout the semester in order to encourage proper progress toward the goal of participating in the final class competition; this event is where guests are invited and small prizes are awarded for the top three finishers. This style of project-based-learning provides students with opportunities to gain practical skills and, with these skills, to increase confidence in their abilities to design and solve real-world problems. Additionally, I have found student motivation and interest to be high, which leads to increased rates of learning and accomplishment. Since the cost of the components is kept low (approximately $60), each student retains his/her respective robot and can continue working with it beyond the completion of the course

    Statement of Integration of Faith and the Engineering Discipline

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    Oxidation of Reduced Sulfur Compounds: A Triple-oxygen-isotope Perspective

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    The Earth’s geochemical evolution is recorded in the rocks that compose its lithosphere. Specifically, sulfate minerals have been identified as being repositories of information concerning the past hydrosphere, atmosphere and biosphere. This is due to the non-labile nature of SO42- and its ability to store a record of the oxidative reactions and oxygen sources involved in its formation. Microbial dissimilatory sulfate reduction (MDSR) and sulfide oxidation cause oxygen from H2O and O2 to be trapped to varying degrees in ambient, dissolved SO42-. In order to better interpret the H2O and O2 signals in SO42-, we must deepen our understanding of how sulfur redox processes incorporate and preserve O2 and H2O oxygen signals in SO42-. I attack this problem through 3 main questions. 1) Does the SO42- contained in the MDSR-intermediate, adenosine-5’-phosphosulfate (APS) exchange oxygen with water? 2) Can we predict the oxygen source ratios (O2:H2O) in SO42- produced from aerated pyrite oxidation, variable pH (2-11)and variable [Fe3+]? 3) How does the pH dependent competition between sulfite-water-oxygen exchange and sulfite oxidation effect the source ratios (O2:H2O) in produced SO42-? Each question constitutes an individual chapter in my dissertation. I show that APS-sulfate and water-oxygen do not exchange. The sulfite (SO32-)-H2O-oxygen exchange processes, in competition with SO32- oxidation, was determined to control the O2: H2O oxygen source ratio for SO42- formed during the oxidation of pyrite, resulting in a consistent O2-oxygen% in SO42- (25 ± 4%) produced from pyrite oxidation between pH 2-11. Slight differences in the oxygen source ratios found in these experiments point to the pH dependent rate competition between SO32--H2O-oxygen exchange and SO32- production vs. SO32- to SO42- oxidation. SO32- oxidation was found to be more sensitive to pH than exchange, which results in less H2O-oxygen being incorporated in precipitated SO42- produced from pyrite and SO32 at lower pH. This was assisted by a unique oxygen isotope parameter used in my experiments, the 17O-label. This study should provide a template for future use of 17O-labeled solutions in determining the role of H2O, O2, or O3 in the formation of other oxyanions

    Identification of the Coronal Sources of the Fast Solar Wind

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    The present spectroscopic study of the ultraviolet coronal emission in a polar hole, detected on April 6-9, 1996 with the Ultraviolet Coronagraph Spectrometer aboard the SOHO spacecraft, identifies the inter-plume lanes and background coronal hole regions as the channels where the fast solar wind is preferentially accelerated. In inter-plume lanes, at heliocentric distance 1.7 \rsun, the corona expands at a rate between 105 km/s and 150 km/s, that is, much faster than in plumes where the outflow velocity is between 0 km/s and 65 km/s. The wind velocity is inferred from the Doppler dimming of the O VI λλ\lambda\lambda 1032, 1037 \AA lines, within a range of values, whose lower and upper limit corresponds to anisotropic and isotropic velocity distribution of the oxygen coronal ions, respectively.Comment: 14 pages, 4 figures, 3 tables, Accepted by ApJ Letter

    The effect of fuel-to-air ratio on burner-rig hot corrosion

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    Samples of a cobalt-base alloy, Mar M-509, were subjected to hot corrosion in a Mach-0.3 burner rig. The corrodent was NaCl added as an aqueous solution to the combustion products of a sulfur-containing Jet-A fuel. The metal temperature was fixed at 900 C. The extent of hot corrosion increased by a factor of three as the fuel-to-air mass ratio was increased from 0.033 to 0.050. Because the depositing salt was always Na2SO4, the increased attack appeared to be related to the gas composition

    A Model for the Stray Light Contamination of the UVCS Instrument on SOHO

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    We present a detailed model of stray-light suppression in the spectrometer channels of the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. The control of diffracted and scattered stray light from the bright solar disk is one of the most important tasks of a coronagraph. We compute the fractions of light that diffract past the UVCS external occulter and non-specularly pass into the spectrometer slit. The diffracted component of the stray light depends on the finite aperture of the primary mirror and on its figure. The amount of non-specular scattering depends mainly on the micro-roughness of the mirror. For reasonable choices of these quantities, the modeled stray-light fraction agrees well with measurements of stray light made both in the laboratory and during the UVCS mission. The models were constructed for the bright H I Lyman alpha emission line, but they are applicable to other spectral lines as well.Comment: 19 pages, 5 figures, Solar Physics, in pres
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