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Sample records for edwards mira bileaflet

  1. Wonderful Mira.

    PubMed

    Wareing, Christopher John

    2008-12-13

    Since being named 'wonderful' in the seventeenth century for its peculiar brightness variability, Mira A has been the subject of extensive research and become the prototype for a whole class of 'Mira' variable stars. The primary star in a binary system, Mira A is reaching the end of its life and currently undergoing an extended period of enhanced mass loss. Recent observations have revealed a surrounding arc-like structure and a stream of material stretching 12 light years away in opposition to the arc. In this article, I review recent modelling of this cometary appearance as a bow shock with an accompanying tail of material ram pressure stripped from the head of the bow shock, place Mira in an evolutionary context, predict its future with reference to the similar star R Hya and planetary nebula Sh 2-188, and speculate some avenues of research both on Mira itself and on other 'Mira-like' stars with bow shocks and tails. I also discuss the implications of this discovery for our own star, the Sun. PMID:18812301

  2. Flares on Mira stars?

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1991-01-01

    Fourteen cases of flares reported on Mira type stars have been collected. These flares typically have an amplitude of over half a magnitude, a rise time of minutes, and a duration of tens of minutes. Nine of the 11 stars represent a normal cross section of the Mira population, while the remaining two are in symbiotic systems (CH Cyg and RX Pup). The flares were observed photographically (five cases), photometrically (three cases), visually (three cases), and with radio telescopes (two cases), while CH Cyg has had flares observed by many techniques. The evidence for the existence of flares on Miras is strong but not definitive. It is possible to hypothesize a variety of background or instrumental effects that could explain all 14 events; however, there is no evidence that suggests the data should be taken at other than face value, and there are good arguments for rejecting the possibility of artifacts. It is felt that the current data warrant systematic observational and theoretical investigation of the possibility of flares on Mira stars.

  3. Leaflet escape in a revised Edwards-Duromedics mitral prosthesis.

    PubMed

    Mert, Murat; Ozkara, Ahmet; Hatemi, AliCan

    2003-07-01

    The original Duromedics-Edwards bileaflet valve was withdrawn from the market in 1988 after 12 reports of leaflet escape. The leaflet was modified by the manufacturer, and the revised Edwards-Duromedics and Edwards TEKNA valves were introduced in 1990 and 1993, respectively. However, problems of leaflet escape have now been reported with the new models. A case is reported of sudden leaflet fracture of a revised Duromedics mitral valve 86 months after implantation; this was managed successfully by emergency replacement with a St. Jude Medical mechanical prosthesis. The fracture had occurred transversely, with the two fragments embolizing bilaterally to the right common iliac and left external iliac arteries. In the absence of an exact diagnosis, but with a high index of suspicion, the key to survival of patients with leaflet escape is immediate reoperation. PMID:12918855

  4. Mira Soars Through the Sky

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    New ultraviolet images from NASA's Galaxy Evolution Explorer shows a speeding star that is leaving an enormous trail of 'seeds' for new solar systems. The star, named Mira (pronounced my-rah) after the latin word for 'wonderful,' is shedding material that will be recycled into new stars, planets and possibly even life as it hurls through our galaxy.

    In figure 1, the upper panel shows Mira's full, comet-like tail as seen only in shorter, or 'far' ultraviolet wavelengths, while the lower panel is a combined view showing both far and longer, or 'near' ultraviolet wavelengths. The close-up picture at bottom gives a better look at Mira itself, which appears as a pinkish dot, and is moving from left to right in this view. Shed material appears in light blue. The dots in the picture are stars and distant galaxies. The large blue dot on the left side of the upper panel, and the large yellow dot in the lower panel, are both stars that are closer to us than Mira.

    The Galaxy Evolution Explorer discovered the strange tail during part of its routine survey of the entire sky at ultraviolet wavelengths. When astronomers first saw the picture, they were shocked because Mira has been studied for over 400 years yet nothing like this has ever been documented before.

    Mira's comet-like tail stretches a startling 13 light-years across the sky. For comparison, the nearest star to our sun, Proxima Centauri, is only about 4 light-years away. Mira's tail also tells a tale of its history -- the material making it up has been slowly blown off over time, with the oldest material at the end of the tail being released about 30,000 years ago (figure 2).

    Mira is a highly evolved, 'red giant' star near the end of its life. Technically, it is called an asymptotic giant branch star. It is red in color and bloated; for example, if a red giant were to replace

  5. Mira Soars Through the Sky

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    New ultraviolet images from NASA's Galaxy Evolution Explorer shows a speeding star that is leaving an enormous trail of 'seeds' for new solar systems. The star, named Mira (pronounced my-rah) after the latin word for 'wonderful,' is shedding material that will be recycled into new stars, planets and possibly even life as it hurls through our galaxy.

    In figure 1, the upper panel shows Mira's full, comet-like tail as seen only in shorter, or 'far' ultraviolet wavelengths, while the lower panel is a combined view showing both far and longer, or 'near' ultraviolet wavelengths. The close-up picture at bottom gives a better look at Mira itself, which appears as a pinkish dot, and is moving from left to right in this view. Shed material appears in light blue. The dots in the picture are stars and distant galaxies. The large blue dot on the left side of the upper panel, and the large yellow dot in the lower panel, are both stars that are closer to us than Mira.

    The Galaxy Evolution Explorer discovered the strange tail during part of its routine survey of the entire sky at ultraviolet wavelengths. When astronomers first saw the picture, they were shocked because Mira has been studied for over 400 years yet nothing like this has ever been documented before.

    Mira's comet-like tail stretches a startling 13 light-years across the sky. For comparison, the nearest star to our sun, Proxima Centauri, is only about 4 light-years away. Mira's tail also tells a tale of its history -- the material making it up has been slowly blown off over time, with the oldest material at the end of the tail being released about 30,000 years ago (figure 2).

    Mira is a highly evolved, 'red giant' star near the end of its life. Technically, it is called an asymptotic giant branch star. It is red in color and bloated; for example, if a red giant were to replace

  6. Mira: Argonne's 10-petaflops supercomputer

    ScienceCinema

    Papka, Michael; Coghlan, Susan; Isaacs, Eric; Peters, Mark; Messina, Paul

    2014-06-05

    Mira, Argonne's petascale IBM Blue Gene/Q system, ushers in a new era of scientific supercomputing at the Argonne Leadership Computing Facility. An engineering marvel, the 10-petaflops supercomputer is capable of carrying out 10 quadrillion calculations per second. As a machine for open science, any researcher with a question that requires large-scale computing resources can submit a proposal for time on Mira, typically in allocations of millions of core-hours, to run programs for their experiments. This adds up to billions of hours of computing time per year.

  7. Mira: Argonne's 10-petaflops supercomputer

    SciTech Connect

    Papka, Michael; Coghlan, Susan; Isaacs, Eric; Peters, Mark; Messina, Paul

    2013-07-03

    Mira, Argonne's petascale IBM Blue Gene/Q system, ushers in a new era of scientific supercomputing at the Argonne Leadership Computing Facility. An engineering marvel, the 10-petaflops supercomputer is capable of carrying out 10 quadrillion calculations per second. As a machine for open science, any researcher with a question that requires large-scale computing resources can submit a proposal for time on Mira, typically in allocations of millions of core-hours, to run programs for their experiments. This adds up to billions of hours of computing time per year.

  8. Mechanical heart valve cavitation in patients with bileaflet valves.

    PubMed

    Johansen, Peter; Andersen, Tina S; Hasenkam, J Michael; Nygaard, Hans; Paulsen, Peter K

    2014-01-01

    Today, the quality of mechanical heart valves is quite high, and implantation has become a routine clinical procedure with a low operative mortality (< 5%). However, patients still face the risks of blood cell damage, thromboembolic events, and material failure of the prosthetic device. One mechanism found to be a possible contributor to these adverse effects is cavitation. In vitro, cavitation has been directly demonstrated by visualization and indirectly in vivo by registering of high frequency pressure fluctuations (HFPF). Tilting disc valves are thought of having higher cavitation potential than bileaflet valves due to higher closing velocities. However, the thromboembolic potential seems to be the same. Further studies are therefore needed to investigate the cavitation potential of bileaflet valves in vivo. The post processing of HFPF have shown difficulties when applied on bileaflet vavles due to asynchronous closure of the two leaflets. The aim of this study was therefore to isolate the pressure signature from each leaflet closure and perform cavitation analyses on each component. Six patients were included in the study (St. Jude Medical (n=3) and CarboMedics (n=3); all aortic bileaflet mechanical heart valves). HFPFs were recorded intraoperatively through a hydrophone at the aortic root. The pressure signature relating to the first and second leaflet closure was isolated and cavitation parameters were calculated (RMS after 50 kHz highpass filtering and signal energy). Data were averaged over 30 heart cycles. For all patients both the RMS value and signal energy of the second leaflet closure were higher than for the first leaflet closure. This indicates that the second leaflet closure is most prone to cause cavitation. Therefore, quantifying cavitation based on the HFPF related to the second leaflet closure may suggest that the cavitation potential for bileaflet valves in vivo may be higher than previous studies have suggested. PMID:25571278

  9. Fatal leaflet escape in an Edwards TEKNA aortic prosthesis.

    PubMed

    Pfeiffer, Heidi; Bertolini, Julia; Scheld, Hans Heinrich; Brinkmann, Bernd

    2006-01-01

    The case is reported of a 26-year-old male patient who died eight years after the replacement of an aortic valve with a bileaflet mechanical valve (TEKNA; Edwards, USA). Following prosthesis implantation, the patient had been in a good state of health, and his death occurred unexpectedly. Forensic autopsy revealed a leaflet escape, with two fragments of the leaflet being found bilaterally in the common iliac arteries. Death occurred due to an acute cardiac insufficiency. Immunohistochemical investigations revealed fresh myocardial fiber necroses. Stereomicroscopic and scanning electron microscopic investigations demonstrated surface erosions of the leaflet. Although the valve was withdrawn from the market in June 2000, it had previously been implanted in over 18,000 patients. Thus, from a clinical viewpoint, the question of using a prophylactic replacement in affected patients must be discussed. PMID:16480019

  10. Motion Imagery and Robotics Application Project (MIRA)

    NASA Technical Reports Server (NTRS)

    Grubbs, Rodney P.

    2010-01-01

    This viewgraph presentation describes the Motion Imagery and Robotics Application (MIRA) Project. A detailed description of the MIRA camera service software architecture, encoder features, and on-board communications are presented. A description of a candidate camera under development is also shown.

  11. Effects of bileaflet mechanical heart valve orientation on coronary flow

    NASA Astrophysics Data System (ADS)

    Haya, Laura; Tavoularis, Stavros

    2015-11-01

    The aortic sinus is approximately tri-radially symmetric, but bileaflet mechanical heart valves (BMHVs), which are commonly used to replace diseased aortic valves, are bilaterally symmetric. This mismatch in symmetry suggests that the orientation in which a BMHV is implanted within the aortic sinus affects the flow characteristics downstream of it. This study examines the effect of BMHV orientation on the flow in the coronary arteries, which originate in the aortic sinus and supply the heart tissue with blood. Planar particle image velocimetry measurements were made past a BMHV mounted at the inlet of an anatomical aorta model under physiological flow conditions. The complex interactions between the valve jets, the sinus vortex and the flow in the right coronary artery were elucidated for three valve orientations. The coronary flow rate was directly affected by the size, orientation, and time evolution of the vortex in the sinus, all of which were sensitive to the valve's orientation. The total flow through the artery was highest when the valve was oriented with its axis of symmetry intersecting the artery's opening. The findings of this research may assist surgeons in choosing the best orientation for BMHV implantation. The bileaflet valve was donated by St. Jude Medical. Financial support was provided by the Natural Sciences and Engineering Research Council of Canada.

  12. Measurements of flow past a bileaflet mechanical heart valve

    NASA Astrophysics Data System (ADS)

    Haya, Laura; Tavoularis, Stavros

    2013-11-01

    A bileaflet mechanical heart valve has been inserted in an axisymmetric model of the aorta within a mock circulation apparatus with physiological pressure and flow variations. The velocity field behind the valve has been measured with laser Doppler velocimetry and particle image velocimetry. The results closely match those reported by similar studies. A triple jet emanated from the valve's orifices and regions of reverse flow formed in the sinus region. Velocity fluctuations were greatest in the shear layers of the jets. The average r.m.s. streamwise velocity fluctuation over the turbulent period was 0.22 m/s; its maximum value was 0.53 m/s and occurred at the onset of deceleration. Measurements with the valve inserted in an anatomical model of the aorta are planned for the near future. The present and future measurements will be compared to determine the effects of the aorta anatomy on the characteristics of flow through bileaflet valves. In particular, measurements of the viscous and turbulent shear stresses will be analyzed to identify possible locations of blood element damage, and regions of recirculation and stagnation will be identified as locations favourable to thrombus growth. The effects of flows in branching arteries and valve orientation will also be investigated. Supported by NSERC.

  13. Introducing Mira, Argonne's Next-Generation Supercomputer

    SciTech Connect

    2013-03-19

    Mira, the new petascale IBM Blue Gene/Q system installed at the ALCF, will usher in a new era of scientific supercomputing. An engineering marvel, the 10-petaflops machine is capable of carrying out 10 quadrillion calculations per second.

  14. Motion Imagery and Robotics Application (MIRA)

    NASA Technical Reports Server (NTRS)

    Martinez, Lindolfo; Rich, Thomas

    2011-01-01

    Objectives include: I. Prototype a camera service leveraging the CCSDS Integrated protocol stack (MIRA/SM&C/AMS/DTN): a) CCSDS MIRA Service (New). b) Spacecraft Monitor and Control (SM&C). c) Asynchronous Messaging Service (AMS). d) Delay/Disruption Tolerant Networking (DTN). II. Additional MIRA Objectives: a) Demo of Camera Control through ISS using CCSDS protocol stack (Berlin, May 2011). b) Verify that the CCSDS standards stack can provide end-to-end space camera services across ground and space environments. c) Test interoperability of various CCSDS protocol standards. d) Identify overlaps in the design and implementations of the CCSDS protocol standards. e) Identify software incompatibilities in the CCSDS stack interfaces. f) Provide redlines to the SM&C, AMS, and DTN working groups. d) Enable the CCSDS MIRA service for potential use in ISS Kibo camera commanding. e) Assist in long-term evolution of this entire group of CCSDS standards to TRL 6 or greater.

  15. Edward Hopper: The Watercolors.

    ERIC Educational Resources Information Center

    Johnson, Mark M.

    2000-01-01

    Provides information on Edward Hopper, focusing on his use of watercolors. Explores five of his watercolor paintings: (1) "The Mansard Roof"; (2) "House on Pamet River"; (3) "Light at Two Lights"; (4) "Saltillo Mansion"; and (5) "Roofs of Washington Square." Addresses the exhibition "Edward Hopper: The Watercolors." (CMK)

  16. The Bright Symbiotic Mira EF Aquilae

    NASA Astrophysics Data System (ADS)

    Margon, Bruce; Prochaska, J. Xavier; Tejos, Nicolas; Monroe, TalaWanda

    2016-02-01

    An incidental spectrum of the poorly studied long-period variable EF Aquilae shows [O III] emission indicative of a symbiotic star. Strong GALEX detections in the UV reinforce this classification, providing overt evidence for the presence of the hot subluminous companion. Recent compilations of the photometric behavior strongly suggest that the cool component is a Mira variable. Thus EF Aql appears to be a member of the rare symbiotic Mira subgroup.

  17. Is Mira a magneto-dusty rotator?

    NASA Astrophysics Data System (ADS)

    Thirumalai, Anand; Heyl, Jeremy S.

    2013-04-01

    We investigate the possibility that a magnetic field may be present in the star o-Ceti (hereafter Mira) and that the field plays a role in the star's mass loss. The model presented here is an application of an earlier derived theory that has been successfully applied for modelling the wind of a generic intermediate-mass asymptotic giant branch (AGB) star and that of the red supergiant star Betelgeuse, and is now extended to the low-mass end AGB stars, Mira. The modelling shows that it is possible to obtain a hybrid magnetohydrodynamic-dust-driven wind scenario for Mira, in which the magnetic field in the equatorial plane of the star is dynamically important for producing a stellar wind. The wind velocity and the temperatures obtained from the model appear consistent with observational findings elsewhere.

  18. Atmospheric structure and mass loss in Miras

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth H.; Lebzelter, Thomas; Straniero, Oscar

    2016-07-01

    The cool molecular region of late-type stellar atmospheres, the ‘MOLsphere’ located between the photosphere and expanding circumstellar shell, is explored by using time series of near-IR spectra of one large amplitude AGB (Mira) variable. The ∼⃒1400 K MOLsphere of the Mira R Cas is shown to undergo large amplitude velocity changes that are aperiodic with time scales many times longer than the photospheric pulsation. The mass of the MOLsphere is ∼⃒3×10‑5 M⊙. Initial analysis suggests that MOLsphere is thin compared to the stellar radius.

  19. Mira's role in RR Tel revisited

    NASA Astrophysics Data System (ADS)

    Heck, A.; Manfroid, J.

    The present uvby data, IUE FES measurements and American Association of Variable Star Observers visual estimates of the very slow nova RR Tel show that the object has gone through periodic variations in visual light since it started fading in 1949 after the outburst it incurred in 1944. The period is, however, not constant, and varies between 350 and 410 days, confirming Mayall's (1957) statement and contradicting the conclusions of later investigators. Synchronized variations of a Mira in the infrared and of a blue component indicate that the Mira mass outflow probably varies in a phase with its pulsations. Large variations occur in visual light on a time scale of a few weeks.

  20. Edward Everett Hale

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The first known proposal for a marned-satellite appeared in a story by Edward Everett Hale entitled The Brick Moon. The story involved a group of young Bostonians who planned to put an artificial satellite into polar orbit for sailors to use to determine longitude accurately and easily.

  1. A novel computational model for the hemodynamics of bileaflet mechanical valves in the opening phase.

    PubMed

    Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

    2015-03-01

    A powerful alternative means to study the hemodynamics of bileaflet mechanical heart valves is the computational fluid dynamics method. It is well recognized that computational fluid dynamics allows reliable physiological blood flow simulation and measurements of flow parameters. To date, in almost all of the modeling studies on the hemodynamics of bileaflet mechanical heart valves, a velocity (mass flow)-based boundary condition and an axisymmetric geometry for the aortic root have been assigned, which, to some extent, are erroneous. Also, there have been contradictory reports of the profile of velocity in downstream of leaflets, that is, in some studies, it is suggested that the maximum blood velocity occurs in the lateral orifice, and in some other studies, it is postulated that the maximum velocities in the main and lateral orifices are identical. The reported values for the peak velocities range from 1 to 3 m/s, which highly depend on the model assumptions. The objective of this study is to demonstrate the importance of the exact anatomical model of the aortic root and the realistic boundary conditions in the hemodynamics of the bileaflet mechanical heart valves. The model considered in this study is based on the St Jude Medical valve in a novel modeling platform. Through a more realistic geometrical model for the aortic root and the St Jude Medical valve, we have developed a new set of boundary conditions in order to be used for the assessment of the hemodynamics of aortic bileaflet mechanical heart valves. The results of this study are significant for the design improvement of conventional bileaflet mechanical heart valves and for the design of the next generation of prosthetic valves. PMID:25833999

  2. The Spectra of Mira Variable Stars.

    NASA Astrophysics Data System (ADS)

    Crowe, Richard Alan

    The catalog of Keenan, Garrison and Deutsch (1974) has been extended by the addition of 483 blue spectrograms of 72 Southern Hemisphere Mira variables. About 190 direct and image-tube plates at a dispersion of 120 (ANGSTROM)/mm were obtained in Chile between 1977 and 1982. Spectral types, emission-line ratios for H(delta) 4101/H(gamma) 4340/H(beta) 4861 and eye-estimated intensities of the absorption lines Ca I (lamda)4226, Cr I (lamda)4254 and Sr II (lamda)4077 have been tabulated. Spectral montages for six stars are used to illustrate changes in the visual spectra of Mira variables through their respective cycles. Radial velocities of absorption and emission line systems have been determined for 22 Northern Hemisphere Mira variables. These were measured from approximately 65 spectra obtained on baked IIa-O plates at a dispersion of 12 (ANGSTROM)/mm with the DDO 1.88-m telescope. Most of these Northern Hemisphere stars were observed close to maximum light, and so only in a few cases (for example, R Trianguli) is there any useful phase information available. It can be shown from this data that the irregular behaviour of absorption features in Mira variables is the consequence of a second shock front which is higher up in the atmosphere than the one producing Balmer emission, as has been proposed by Hill and Willson, 1979b). We present evidence that strong emission is associated with weak-line cycles (when overlying TiO absorption is also weaker) and that the velocity gradient is directly responsible for the weakening by the escape enhancement process (Mihalas, 1978). Since the shock strength varies from cycle to cycle, we do not expect the affected lines to maintain the same equivalent width at the same phase in different cycles. There is, however, a great deal of internal scatter from star to star which confuses the interpretation. The separation of Mira variables into two groups (namely, those with spectral types earlier and later than M5e at maximum light) helps

  3. The radio continuum spectrum of Mira A and Mira B up to submillimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Planesas, P.; Alcolea, J.; Bachiller, R.

    2016-02-01

    Aims: We present new measurements of the flux densities at submillimeter wavelengths based on ALMA band 7 (338 GHz, λ0.89 mm) and band 9 (679 GHz, λ0.44 mm) observations to better constrain the origin of the continuum emission of the Mira AB binary system and to check its orbit. Methods: We have measured the Mira A and Mira B continuum in ALMA band 7, with a resolution of ~0.̋31, and for the first time in ALMA band 9, with a resolution of ~0.̋18. We have resolved the binary system at both bands, and derived the continuum spectral index of the stars and their relative position. We also analyzed ALMA Science Verification data obtained in bands 6 and 3. Measurements at centimeter wavelengths obtained by other authors have been included in our study of the spectral energy distribution of the Mira components. Results: The Mira A continuum emission has a spectral index of 1.98 ± 0.04 extending from submillimeter down to centimeter wavelengths. The spectral index of the Mira B continuum emission is 1.93 ± 0.06 at wavelengths ranging from submillimeter to ~3.1 mm, and a shallower spectral index of 1.22 ± 0.09 at longer wavelengths. The high precision relative positions of the A and B components are shown to significantly depart from the current (preliminary) orbit by ~14 mas. Conclusions: The Mira A continuum emission up to submillimeter wavelengths is consistent with that of a radio photosphere surrounding the evolved star for which models predict a spectral index close to 2. The Mira B continuum emission cannot be described with a single ionized component. An extremely compact and dense region around the star can produce the nearly thermal continuum measured in the range λ0.4-3.1 mm, and an inhomogeneous, less dense, and slightly larger ionized envelope could be responsible for the emission at longer wavelengths. Our results illustrate the potential of ALMA for high precision astrometry of binary systems. We have found a significant discrepancy between the ALMA

  4. Edward Teller's Scientific Life

    SciTech Connect

    Libby, S B; Weiss, M S

    2004-04-15

    Edward Teller was one of the great physicists of the twentieth century. His career began just after the key ideas of the quantum revolution of the 1920's were completed, opening vast areas of physics and chemistry to detailed understanding. Thus, his early work in theoretical physics focused on applying the new quantum theory to the understanding of diverse phenomena. These topics included chemical physics, diamagnetism, and nuclear physics. Later, he made key contributions to statistical mechanics, surface physics, solid state, and plasma physics. In many cases, the ideas in these papers are still rich with important ramifications.

  5. Large stellar interferometer MIRA-ST

    NASA Astrophysics Data System (ADS)

    Yoshizawa, Masanori; Sato, Koichi; Nishikawa, Jun; Ohishi, Naoko; Kotani, Takayuki

    2003-02-01

    We propose a millisecond of arc optical/infrared array for stellar territory, MIRA-ST, with nine 4m-aperture off-axis telescopes, whose maximum baseline length is about 600 m. MIRA-ST will have the photon collecting area equivalent to that of a single-dish telescope of 12 m diameter, and the imaging capability better than 1 millisecond of arc resolution at 2.2 micrometers with a high dynamic range of reconstructed images. Combining the light beams from each pupil telescope efficiently is one of the most difficult tasks. We compare the relative merits among a so-called pair-wise beam combining, an all-on-one beam combining, and a tree-structured beam combining. As for transferring the beams from individual telescopes to a beam combining facility with the loss of photons as small as possible, an optical fiber system is a most interesting substitute for the current mirror-and-vacuum-pipe combination. Specifically, the nature of spatial filtering of optical fibers has been under study in the light of deepening the limiting magnitude attainable without introducing an adaptive optics to each telescope. With MIRA-ST we will be able to zoom in the stellar territory to unveil the detailed structures and lifecycles of stars of various kinds, and to examine the universality and/or diversity along the coarse of their evolutionary paths. The specific targets of most interesting for us are, among others, T Tauri stars, AGB and post-AGB stars, Cepheids, brown dwarfs, white dwarfs, stellar atmosphere/envelope of low temperature stars, accretion disks, and fundamental structures of main sequence stars.

  6. Edward (Ed) T. Schneider

    NASA Technical Reports Server (NTRS)

    1984-01-01

    NASA research pilot Edward T. Schneider in the cockpit of an F-104. Schneider served as a U.S. Navy pilot from 1968 to 1983, during which time he trained at the U.S. Naval Test Pilot School, and received assignments as an engineering test pilot, as a test pilot school instructor, and as a Naval Liaison Officer at what was then called the Ames-Dryden Flight Research Facility (now the Dryden Flight Research Center). Schneider joined NASA as a research pilot in 1983. Over the next 17 years, he was a project pilot on the F-18 High Angle-of-Attack program, the F-15 aeronautical research aircraft, the B-52 launch aircraft, and the NASA SR-71s. He retired as a NASA research pilot in September 2000.

  7. Edward Teller Biographical Memoir

    SciTech Connect

    Libby, S B; Sessler, A M

    2009-07-27

    Edward Teller died on September 9, 2003 in Stanford, California at the age of 95. He was both one of the great theoretical physicists of the twentieth century and a leading figure in the development of nuclear weapons and broader defense advocacy. Teller's work in physics, spanning many decades of the twentieth century, includes some of the most fundamental insights in the quantum behaviors of molecules and their spectra, nuclei, surfaces, solid state and spin systems, and plasmas. In the defense arena, Teller is best known for his key insight that made thermonuclear weapons possible. Teller was both a great scientific collaborator and physics teacher at all levels, known for his openness, generosity, personal warmth, and powerful physical intuition. Many of his graduate students went on to illustrious careers.

  8. Pulsation and mass loss in Mira variables

    NASA Technical Reports Server (NTRS)

    Wood, P. R.

    1980-01-01

    The behavior of pulsation in the outer layers of a typical Mira variable was studied in the adiabatic and isothermal limits. A shock wave propagates outward once per period and the radial velocity obtained from observations of hydrogen emission lines is identified with the velocity of gas in the post shock region. In the adiabatic case, mass loss in the form of a steady stellar wind was produced. In the isothermal case, no continuous mass loss was produced but occasional ejection of shells occur. Pulsation introduced into a star undergoing steady mass loss as a result of radiation pressure acting on grains caused the mass loss rate to increase by a factor of approximately 40, while the terminal velocity of the flow was almost unaltered.

  9. 02-NIF Dedication: Edward Moses

    ScienceCinema

    Edward Moses

    2010-09-01

    The National Ignition Facility, the world's largest laser system, was dedicated at a ceremony on May 29, 2009 at Lawrence Livermore National Laboratory. These are the remarks by NIF Director Edward Moses.

  10. 02-NIF Dedication: Edward Moses

    SciTech Connect

    Edward Moses

    2009-07-02

    The National Ignition Facility, the world's largest laser system, was dedicated at a ceremony on May 29, 2009 at Lawrence Livermore National Laboratory. These are the remarks by NIF Director Edward Moses.

  11. Edward Bancroft's "Torporific Eels".

    PubMed

    Finger, Stanley

    2009-01-01

    Edward Bancroft was a medical apprentice in Connecticut before running off to Guiana in 1763. While in South America, he practiced medicine and collected material for a lengthy book on the region, which he published after he settled in London. Bancroft's Essay (1769) contains a description of the "torporific eels" found in the warm rivers of Guiana, along with a series of experiments suggesting that the eel's powers are electrical. It also calls for studies to determine whether saltwater torpedo rays might demonstrate the same properties, which Bancroft expected would be the case. Today, Bancroft is best remembered for serving Benjamin Franklin and the American delegation in France during the War of Independence, and for being a double agent. But what this colorful man wrote about the South American eels helped to make an early case for animal electricity and stimulated Franklin to encourage John Walsh to conduct his landmark electrical experiments on torpedoes and electric eels in the 1770s. These efforts led to new way of thinking about the physiology of the nervous and muscular systems, even in nonspecialized fish. PMID:19168945

  12. Edward A. Bouchet

    NASA Astrophysics Data System (ADS)

    Mickens, R. E.

    2002-04-01

    Edward A. Bouchet was the first African American to receive the doctorate in any field of knowledge in the United States and that area was physics. He was granted the degree in 1876 from Yale University making him at that time one of the few persons to hold the physics doctorate from an American university. His prior education included the Hopkins Grammar School and Yale College (BA in 1874). After Yale, Bouchet taught mathematics, physics, and chemistry for over twenty-five years at the Institute for Colored Youth in Philadelphia. During the following two decades, he was employed in positions ranging from high school principal to employment by the federal government. Bouchet played a significant role in the education of African Americans through his teaching and mentoring activities. He was one among a small group of African Americans who achieved advanced training and education within decades of the American civil war. These individuals provided direction, leadership, and role models for what eventually became the civil/human rights movements. The year 2001 marks the 125th celebration of his receiving the doctorate. We present details of his life and career with an emphasis on the influence of the political and social forces exerted on him by society.

  13. Discovering Mira Ceti: Celestial Change and Cosmic Continuity

    NASA Astrophysics Data System (ADS)

    Hatch, Robert Alan

    In the short narrative that follows I introduce two new heroes. Although we begin with Fabricius's first sighting in 1596, the new pivot point in the drama is the collaboration between Hevelius and Boulliau that began around 1660. As it happens, Learned Europe paid little attention to Mira in the generation after the first scattered sightings of 1596, indeed, nearly 70 years passed before the New Star was given a working identity. Like Columbus discovering America, Fabricius and Holwarda saw different things - for convenience, I call them Fabricius's Star and Holwarda's Star. Hevelius's Historiola (Danzig, 1662) and Boulliau's Ad astronomos (Paris, 1667) presented a different vision. It made Mira famous. As I shall argue, if Hevelius gave Mira a history, Boulliau gave Mira a future.5 In the end, the New Star not only challenged the ancient cosmos, it became an enduring icon for the New Science, a returning reminder of celestial continuity and cosmic order.

  14. Edward (Ed) T. Schneider

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Research Pilot Edward T. Schneider is shown sitting in the cockpit of a McDonnell Douglas F/A-18 Hornet that was used in the High Angle-of-Attack Research Vehicle (HARV) program at the National Aeronautics and Space Administration's Ames - Dryden Flight Research Facility. When the aircraft arrived at the Dryden Facility in 1987, from the US Naval Air Test Center, Patuxent River, Maryland, it consisted of parts in crates. The aircraft crew made an airplane from those parts, and in doing so they took a 'sow's ear' and created a 'silk purse', thus the name on the side of the aircraft. Ed's helmet is from his time in the Navy. The design was taken from the Flag that is flown on the bow of a Navy ship, referred to as the Jack, and is navy blue with the 50 States being represented by the white stars. Ed arrived at the NASA Ames-Dryden Flight Research Facility (later renamed the Dryden Flight Research Center) on July 5, 1982, as a Navy Liaison Officer, becoming a NASA research pilot one year later. Ed was the project pilot for the F-18 High Angle-of-Attack program and later served as a project pilot for the F-15 aeronautical research aircraft, the NASA B-52 launch aircraft, and the SR-71 'Blackbird' aircraft. He served on active duty with the U.S. Navy from 1968 to 1983. Following squadron service he graduated from the U.S. Naval Test Pilot School, Patuxent River, Maryland, in 1973, and then served as an engineering test pilot, and test pilot school instructor at the Naval Air Test Center. Ed has been an active member of the Society of Experimental Test Pilots since 1974. He was made a Fellow of the Society in 1993 and served as its President in 1993/94. In 1996 he was awarded the NASA Exceptional Service Medal and the American Institute of Aeronautics and Astronautics' Chanute Flight Award. He retired as a NASA research pilot in September 2000.

  15. MIRA: mutual information-based reporter algorithm for metabolic networks

    PubMed Central

    Cicek, A. Ercument; Roeder, Kathryn; Ozsoyoglu, Gultekin

    2014-01-01

    Motivation: Discovering the transcriptional regulatory architecture of the metabolism has been an important topic to understand the implications of transcriptional fluctuations on metabolism. The reporter algorithm (RA) was proposed to determine the hot spots in metabolic networks, around which transcriptional regulation is focused owing to a disease or a genetic perturbation. Using a z-score-based scoring scheme, RA calculates the average statistical change in the expression levels of genes that are neighbors to a target metabolite in the metabolic network. The RA approach has been used in numerous studies to analyze cellular responses to the downstream genetic changes. In this article, we propose a mutual information-based multivariate reporter algorithm (MIRA) with the goal of eliminating the following problems in detecting reporter metabolites: (i) conventional statistical methods suffer from small sample sizes, (ii) as z-score ranges from minus to plus infinity, calculating average scores can lead to canceling out opposite effects and (iii) analyzing genes one by one, then aggregating results can lead to information loss. MIRA is a multivariate and combinatorial algorithm that calculates the aggregate transcriptional response around a metabolite using mutual information. We show that MIRA’s results are biologically sound, empirically significant and more reliable than RA. Results: We apply MIRA to gene expression analysis of six knockout strains of Escherichia coli and show that MIRA captures the underlying metabolic dynamics of the switch from aerobic to anaerobic respiration. We also apply MIRA to an Autism Spectrum Disorder gene expression dataset. Results indicate that MIRA reports metabolites that highly overlap with recently found metabolic biomarkers in the autism literature. Overall, MIRA is a promising algorithm for detecting metabolic drug targets and understanding the relation between gene expression and metabolic activity. Availability and

  16. A D-Shaped Bileaflet Bioprosthesis which Replicates Physiological Left Ventricular Flow Patterns

    PubMed Central

    Tan, Sean Guo-Dong; Kim, Sangho; Hon, Jimmy Kim Fatt; Leo, Hwa Liang

    2016-01-01

    Prior studies have shown that in a healthy heart, there exist a large asymmetric vortex structure that aids in establishing a steady flow field in the left ventricle. However, the implantation of existing artificial heart valves at the mitral position is found to have a negative effect on this physiological flow pattern. In light of this, a novel D-shaped bileaflet porcine bioprosthesis (GD valve) has been designed based on the native geometry mitral valve, with the hypothesis that biomimicry in valve design can restore physiological left ventricle flow patterns after valve implantation. An in-vitro experiment using two dimensional particle velocimetry imaging was carried out to determine the hemodynamic performance of the new bileaflet design and then compared to that of the well-established St. Jude Epic valve which functioned as a control in the experiment. Although both valves were found to have similar Reynolds shear stress and Turbulent Kinetic Energy levels, the novel D-shape valve was found to have lower turbulence intensity and greater mean kinetic energy conservation. PMID:27258099

  17. A D-Shaped Bileaflet Bioprosthesis which Replicates Physiological Left Ventricular Flow Patterns.

    PubMed

    Tan, Sean Guo-Dong; Kim, Sangho; Hon, Jimmy Kim Fatt; Leo, Hwa Liang

    2016-01-01

    Prior studies have shown that in a healthy heart, there exist a large asymmetric vortex structure that aids in establishing a steady flow field in the left ventricle. However, the implantation of existing artificial heart valves at the mitral position is found to have a negative effect on this physiological flow pattern. In light of this, a novel D-shaped bileaflet porcine bioprosthesis (GD valve) has been designed based on the native geometry mitral valve, with the hypothesis that biomimicry in valve design can restore physiological left ventricle flow patterns after valve implantation. An in-vitro experiment using two dimensional particle velocimetry imaging was carried out to determine the hemodynamic performance of the new bileaflet design and then compared to that of the well-established St. Jude Epic valve which functioned as a control in the experiment. Although both valves were found to have similar Reynolds shear stress and Turbulent Kinetic Energy levels, the novel D-shape valve was found to have lower turbulence intensity and greater mean kinetic energy conservation. PMID:27258099

  18. A Model of Mira's Cometary Head/Tail Entering the Local Bubble

    NASA Astrophysics Data System (ADS)

    Esquivel, A.; Raga, A. C.; Cantó, J.; Rodríguez-González, A.; López-Cámara, D.; Velázquez, P. F.; De Colle, F.

    2010-12-01

    We model the cometary structure around Mira as the interaction of an asymptotic giant branch stellar wind from Mira A with a streaming environment. Our simulations introduce the following new element: we assume that after 200 kyr of evolution in a dense environment, Mira entered the Local Bubble (low-density coronal gas). As Mira enters the bubble, the head of the comet expands quite rapidly, while the tail remains well collimated for a >100 kyr timescale. The result is a broad-head/narrow-tail structure that resembles the observed morphology of Mira's comet. The simulations were carried out with our new adaptive grid code WALICXE, which is described in detail.

  19. Maxima and O-C Diagrams for 489 Mira Stars

    NASA Astrophysics Data System (ADS)

    Karlsson, T.

    2013-11-01

    Maxima for 489 Mira stars have been compiled. They were computed with data from AAVSO, AFOEV, VSOLJ, and BAA-VSS and collected from published maxima. The result is presented in a mysql database and on web pages with O-C diagrams, periods and some statistical information for each star.

  20. Mitigation of Shear-Induced Blood Damage by Mechanical Bileaflet Heart Valves

    NASA Astrophysics Data System (ADS)

    Zakharin, Boris; Arjunon, Sivakkumar; Saikrishnan, Neelakantan; Yoganathan, Ajit; Glezer, Ari

    2010-11-01

    The strong transitory shear stress generated during the time-periodic closing of bileaflet mechanical heart valves that is associated with the formation of counter-rotating vortices near the leaflet edges may be damaging to blood elements and may result in platelet activation and therefore thrombosis and thromboembolism complications. These flow transients are investigated using fluorescent PIV in a new, low-volume test setup that reproduces the pulsatile physiological conditions associated with a 25 mm St. Jude Medical valve. The flow transients are partially suppressed and the platelet activation is minimized using miniature vortex generator arrays that are embedded on the surface of the leaflets. Measurements of the ensuing flow taken phase-locked to the leaflet motion demonstrate substantial modification of the transient vertical structures and concomitant reduction of Reynolds shear stresses. Human blood experiments validated the effectiveness of miniature vortex generators in reducing thrombus formation by over 42 percent.

  1. Transapical off-pump Neochord implantation on bileaflet prolapse to treat severe mitral regurgitation.

    PubMed

    Colli, Andrea; Bellu, Roberto; Pittarello, Demetrio; Gerosa, Gino

    2015-10-01

    A 74-year old lady was admitted for the presence of a symptomatic severe mitral regurgitation (MR) due to bileaflet prolapse. The patient refused any surgical conventional procedure because of severe arthrosis and osteoporosis documented by previous fractures requiring knee and hip replacements, and was sent directly to us for transapical off-pump mitral valve repair with Neochord implantation (TOP-MINI procedure). The TOP-MINI procedure was performed under general anaesthesia and transoesophageal echocardiographic guidance. Four Neochordae were implanted on the posterior leaflet and two on the anterior leaflet in order to correct a residual anterior prolapse that was not seen at preoperative screening. After 11 months of follow-up, the patient presented with recurrence of symptomatic moderate MR due to rupture of one of two neochordae implanted on the anterior leaflet and new onset of atrial fibrillation. The patient underwent uneventful mitral valve replacement. PMID:26180097

  2. Effect of the sinus of valsalva on the closing motion of bileaflet prosthetic heart valves.

    PubMed

    Ohta, Y; Kikuta, Y; Shimooka, T; Mitamura, Y; Yuhta, T; Dohi, T

    2000-04-01

    Conventional bileaflet prosthetic mechanical heart valves close passively with backflow. Naturally, the valve has problems associated with closure, such as backflow, water hammer effect, and fracture of the leaflet. On the other hand, in the case of the natural aortic valve, the vortex flow in the sinus of Valsalva pushes the leaflet to close, and the valve starts the closing motion earlier than the prosthetic valve as the forward flow decelerates. This closing mechanism is thought to decrease backflow at valve closure. In this study, we propose a new bileaflet mechanical valve resembling a drawbridge in shape, and the prototype valve was designed so that the leaflet closes with the help of the vortex flow in the sinus. The test valve was made of aluminum alloy, and its closing motion was compared to that of the CarboMedics (CM) valve. Both valves were driven by a computer controlled hydraulic mock circulator and were photographed at 648 frames/s by a high speed charge-coupled device (CCD) camera. Each frame of the valve motion image was analyzed with a personal computer, and the opening angles were measured. The flow rate was set as 5.0 L/min. The system was pulsed with 70 bpm, and the systolic/diastolic ratio was 0.3. Glycerin water was used as the circulation fluid at room temperature, and polystyrene particles were used to visualize the streamline. The model of the sinus of Valsalva was made of transparent silicone rubber. As a result, high speed video analysis showed that the test valve started the closing motion 41 ms earlier than the CM valve, and streamline analysis showed that the test valve had a closing mechanism similar to the natural one with the effect of vortex flow. The structure of the test valve was thought to be effective for soft closure and could solve problems associated with closure. PMID:10816206

  3. Morphology and kinematics of the gas envelope of Mira Ceti

    NASA Astrophysics Data System (ADS)

    Nhung, P. T.; Hoai, D. T.; Diep, P. N.; Phuong, N. T.; Thao, N. T.; Tuan-Anh, P.; Darriulat, P.

    2016-07-01

    Observations of 12CO(3-2) emission of the circumbinary envelope of Mira Ceti, made by Atacama Large Millimetre/sub-millimetre Array, are analysed. The observed Doppler velocity distribution is made of three components: a blueshifted south-eastern arc, which can be described as a ring in slow radial expansion, ˜1.7 km s-1, making an angle of ˜50° with the plane of the sky and born some 2000 years ago; a few arcs, probably born at the same epoch as the blueshifted arc, all sharing Doppler velocities redshifted by approximately 3±2 km s-1 with respect to the main star; thirdly, a central region dominated by the circumbinary envelope, displaying two outflows in the south-western and north-eastern hemispheres. At short distances from the star, up to ˜1.5 arcsec, these hemispheres display very different morphologies: the south-western outflow covers a broad solid angle, expands radially at a rate between 5 and 10 km s-1 and is slightly redshifted; the north-eastern outflow consists of two arms, both blueshifted, bracketing a broad dark region where emission is suppressed. At distances between ˜1.5 and ˜2.5 arcsec the asymmetry between the two hemispheres is significantly smaller and detached arcs, particularly spectacular in the north-eastern hemisphere are present. Close to the stars, we observe a mass of gas surrounding Mira B, with a size of a few tens of au, and having Doppler velocities with respect to Mira B reaching ±1.5 km s-1, which we interpret as gas flowing from Mira A towards Mira B.

  4. Morphology and kinematics of the gas envelope of Mira Ceti

    NASA Astrophysics Data System (ADS)

    Nhung, P. T.; Hoai, D. T.; Diep, P. N.; Phuong, N. T.; Thao, N. T.; Tuan-Anh, P.; Darriulat, P.

    2016-04-01

    Observations of 12CO(3-2) emission of the circumbinary envelope of Mira Ceti, made by ALMA are analysed. The observed Doppler velocity distribution is made of three components: a blue-shifted south-eastern arc, which can be described as a ring in slow radial expansion, ˜1.7 km s-1, making an angle of ˜50° with the plane of the sky and born some 2000 years ago; a few arcs, probably born at the same epoch as the blue-shifted arc, all sharing Doppler velocities red-shifted by approximately 3±2 km s-1 with respect to the main star; the third, central region dominated by the circumbinary envelope, displaying two outflows in the south-western and north-eastern hemispheres. At short distances from the star, up to ˜1.5″, these hemispheres display very different morphologies: the south-western outflow covers a broad solid angle, expands radially at a rate between 5 and 10 km s-1 and is slightly red shifted; the north-eastern outflow consists of two arms, both blue-shifted, bracketing a broad dark region where emission is suppressed. At distances between ˜1.5″ and ˜2.5″ the asymmetry between the two hemispheres is significantly smaller and detached arcs, particularly spectacular in the north-eastern hemisphere are present. Close to the stars, we observe a mass of gas surrounding Mira B, with a size of a few tens of AU, and having Doppler velocities with respect to Mira B reaching ±1.5 km s-1, which we interpret as gas flowing from Mira A toward Mira B.

  5. Hydrogen Lines in Mira Stars Through Interferometry and Polarimetry

    NASA Astrophysics Data System (ADS)

    Fabas, N.; Chiavassa, A.; Millour, F.; Wittkowski, M.

    2015-12-01

    Balmer lines in emission are the most prominent features in Mira stars spectra and have a strong potential as a proxy to study the lower atmosphere's dynamics. In Fabas et al. ([1]), we accumulated spectropolarimetric observations of Balmer lines in emission. As the shock is propagating outwards, linear polarization rate increases and the angle of this polarization evolves. Assuming that linear polarization arises from anisotropic scattering, it has the potential of telling us about the geometric structure of the shock as it propagates and the study of such atmospheric structures can typically be performed with interferometry. In 2012, AMBER data on the Mira star omicron Ceti were collected in which the Brackett γ line is studied. The data show signatures in the interferometric observables around this line. Olivier Chesneau was in the jury evaluating the PhD thesis of N. Fabas and he was seduced by the idea to study these shock waves with interferometry and use polarimetry as a complementary study.

  6. Mass loss and OH maser emission from Mira variables

    NASA Technical Reports Server (NTRS)

    Michalitsianos, A. G.; Kafatos, M.

    1978-01-01

    The mass, radius, and luminosity of 26 Mira variables that are known OH sources of radio emission at 1612 MHz have been estimated. The time-independent solution of Salpeter's (1974) stellar-wind equation and a period-density relation are used to solve for basic stellar parameters, with the aid of the terminal expansion velocity of the OH maser cloud. Masses obtained from these calculations are consistent with other estimated values for masses of Mira variables. Good agreement is obtained when comparing the rate of mass loss as determined from Reimers's (1977) semiempirical relation with estimates of the mass-loss rate as deduced from theoretical models involving radiation pressure on grains. These calculations suggest a strong correlation between the mass-loss rate and the pulsation period. Arguments concerning the general properties of silicate grains from radiation-pressure-driven stellar-wind equations are discussed.

  7. Loops in Bandstrength-Color Diagrams for Mira Variables

    NASA Astrophysics Data System (ADS)

    Wing, R. P.

    Narrow-band photometry of Mira variables in the near-infrared (7000-11000 AA) spectral region allows the measurement of colors at relatively good continuum points as well as strong bands of TiO and VO. Several variables including o Cet, chi Cyg, R And, R Cas, R Tri, and IK Tau have been followed through two or more cycles; 27 stars were observed on 10 or more dates. In bandstrength-color diagrams, Mira variables execute large, open loops of varying character and complexity. Several of these are illustrated and discussed. Attempts to model these loops may shed light on the temperature structures of the outer layers of these stars' extended, dynamic atmospheres.

  8. Multi-color interferometric observations of Mira stars

    NASA Technical Reports Server (NTRS)

    Mennesson, B.; Creech-Eakman, M.; Thompson, B. B.; Foresto, V. Coude du; Merand, A.; Ridgway, S.; Perrin, G.

    2002-01-01

    Interferometric observations in the atmospheric windows of the near infrared (1 to 4 microns) can be efficiently used to probe the chemical composition of Miras atmosphere and provide direct measurements of extended gas layers around these stars. This is illustrated by recent Miras observations carried out with the FLUOR instrument of the IOTA interferometer (Mennesson et al. 2002, and Perrin et al. proceedings of this conference) and with the PTI test-bed (Thompson 2002, Thompson et al. 2002). These visibility measurements show evidence for continuum emission from very extended ( 2-3 stellar radii) semi-transparent gaseous atmospheric layers, and large apparent diameter changes with pulsation phase. Interestingly these observations are consistent with the extended molecular gas layers (H20, CO ...) already inferred around some of these objects from IS0 and high resolution ground-based FTS infrared spectra.

  9. Mg II line profiles of the Mira S Carinae

    NASA Technical Reports Server (NTRS)

    Brugel, Edward W.; Bookbinder, Jay A.; Brown, Alexander

    1988-01-01

    High-dispersion IUE observations obtained to investigate the evolution of the shock structure of the Mira S Carinae (S Car) produced, despite very limited phase coverage, a set of five spectra of the Mg II h and k lines. There is significant emission from both the h and k lines at velocities of -150 km/sec relative to the stellar photosphere. The h-to-k ratio of the Mg II doublet remains below the theoretically predicated values of 2:1 to 1:1, and shows a smooth dependence on the optical phase. Archival studies of other Miras (e.g., R Car) indicate that S Car is not unique in possessing unusual and highly variable Mg II h and k line profiles.

  10. Resolving the stellar activity of the Mira AB binary with ALMA

    NASA Astrophysics Data System (ADS)

    Vlemmings, W. H. T.; Ramstedt, S.; O'Gorman, E.; Humphreys, E. M. L.; Wittkowski, M.; Baudry, A.; Karovska, M.

    2015-05-01

    Aims: We present the size, shape, and flux densities at millimeter continuum wavelengths, based on ALMA science verification observations in Band 3 (~94.6 GHz) and Band 6 (~228.7 GHz), from the binary Mira A (o Ceti) and Mira B. Methods: The Mira AB system was observed with ALMA at a spatial resolution down to ~25 mas. The extended atmosphere of Mira A and the wind around Mira B sources were resolved, and we derived the sizes of Mira A and of the ionized region around Mira B. The spectral indices within Band 3 (between 89-100 GHz) and between Bands 3 and 6 were also derived. Results: The spectral index of Mira A is found to change from 1.71 ± 0.05 within Band 3 to 1.54 ± 0.04 between Bands 3 and 6. The spectral index of Mira B is 1.3 ± 0.2 in Band 3, in good agreement with measurements at longer wavelengths; however, it rises to 1.72 ± 0.11 between the bands. For the first time, the extended atmosphere of a star is resolved at these frequencies, and for Mira A the diameter is ~3.8 × 3.2 AU in Band 3 (with brightness temperature Tb ~ 5300 K) and ~4.0 × 3.6 AU in Band 6 (Tb ~ 2500 K). Additionally, a bright hotspot ~0.4 AU, with Tb ~ 10 000 K, is found on the stellar disk of Mira A. The size of the ionized region around the accretion disk of Mira B is found to be ~2.4 AU. Conclusions: The emission around Mira B is consistent with emission from a partially ionized wind of gravitationally bound material from Mira A close to the accretion disk of Mira B. The Mira A atmosphere does not fully match predictions with brightness temperatures in Band 3 significantly higher than expected, potentially owing to shock heating. The hotspot is very likely due to magnetic activity and could be related to the previously observed X-ray flare of Mira A. Appendices are available in electronic form at http://www.aanda.org

  11. Clarence Edwards Middle School: Success through Transformation

    ERIC Educational Resources Information Center

    Massachusetts 2020, 2012

    2012-01-01

    Just a few years ago, Boston's Clarence Edwards Middle School was on the verge of being shut down. By 2009, a renaissance at the Edwards made it one of the highest performing and most desired middle schools in Boston, dramatically narrowing and even eliminating academic achievement gaps while delivering a far more well-rounded education to its…

  12. A biomimetic bi-leaflet mitral prosthesis with enhanced physiological left ventricular swirl restorative capability

    NASA Astrophysics Data System (ADS)

    Tan, Sean Guo-Dong; Kim, Sangho; Leo, Hwa Liang

    2016-06-01

    Mechanical heart valve prostheses are often implanted in young patients due to their durability and long-term reliability. However, existing designs are known to induce elevated levels of blood damage and blood platelet activation. As a result, there is a need for patients to undergo chronic anti-coagulation treatment to prevent thrombosis, often resulting in bleeding complications. Furthermore, recent studies have suggested that the implantation of a mechanical prosthetic valve at the mitral position results in a significant alteration of the left ventricular flow field which may contribute to flow turbulence. This study proposes a bi-leaflet mechanical heart valve design (Bio-MHV) that mimics the geometry of a human mitral valve, with the aim of reducing turbulence levels in the left ventricle by replicating physiological flow patterns. An in vitro three-dimensional particle velocimetry imaging experiment was carried out to compare the hemodynamic performance of the Bio-MHV with that of the clinically established ATS valve. The Bio-MHV was found to replicate physiological left ventricular flow patterns and produced lower turbulence levels.

  13. A numerical investigation of blood damage in the hinge area of bileaflet mechanical heart valves

    NASA Astrophysics Data System (ADS)

    Yun, Min; Wu, Jingshu; Simon, Helene; Sotiropoulos, Fotis; Aidun, Cyrus; Yoganathan, Ajit

    2010-11-01

    Studies have shown that high shear stress and large recirculation regions have a strong impact on thromboembolic complications in Bileaflet mechanical heart valves (BMHV). This study quantitatively compares the hinge flow field and blood damage of the 23mm St. Jude Medical (SJM) regent with different hinge gap widths and the 23mm CarboMedics (CM) valves. The lattice-Boltzmann method with external boundary force (LBM-EBF) [Wu and Aidun, Int. J Num. Methods Fluids, 62, 7, 2009] was implemented to simulate the flow and capture the dynamics and the surface shear stress of the platelets with realistic geometry. The velocity boundary conditions for the small-scale hinge flow are obtained from previous 3D large-scale computational fluid dynamics (CFD) simulations [Simon et al, Annals of Biomedical Engineering, 38, 3, 2009]. The flow patterns of three hinges that were studied were similar during diastole. However, velocity magnitudes and shear stresses at the hinge gap were different, which may explain the higher blood damage index (BDI) value for the CM valve and lower BDI value for the SJM valve with a larger gap width. The multiscale computational method used to quantitatively measure the BDI during a full cardiac cycle will be discussed.

  14. Manipulation of the closing transients of bileaflet mechanical heart valves using passive, surface-mounted elements

    NASA Astrophysics Data System (ADS)

    Simon, Helene

    2005-11-01

    The time-periodic closing of bileaflet mechanical heart valves is accompanied by a strong flow transient that is associated with the formation of a counter-rotating vortex pair near the b-datum line of leaflet edges. The strong transitory shear that is generated by these vortices may be damaging to blood elements and may result in platelet activation. In the present work, these flow transients are mitigated using miniature vortex generator arrays that are embedded on the surface of the leaflets. The closing transients in the absence and presence of the passive vortex generators are characterized using PIV measurements that are phase locked to the leaflet motion. The study utilizes a 25 mm St. Jude Medical valve placed in the aortic position of the Georgia Tech left heart simulator. The valve is subjected to physiological flow conditions: a heart rate of 70 bpm; a cardiac output of 5 l/min; and a mean aortic pressure of 90 mmHg. Measurements of the velocity field in the center plane of the leaflets demonstrate that the dynamics of the transient vortices that precede the formation of the leakage jets can be significantly altered and controlled by relatively simple passive modifications of existing valve designs.

  15. Effect of vortex generators on the closing transient flow of bileaflet mechanical heart valves

    NASA Astrophysics Data System (ADS)

    Murphy, David; Dasi, Lakshmi; Yoganathan, Ajit; Glezer, Ari

    2006-11-01

    The time-periodic closing of bileaflet mechanical heart valves is accompanied by a strong flow transient that is associated with the formation of a counter-rotating vortex pair near the b-datum line of leaflet edges. The strong transitory shear that is generated by these vortices may be damaging to blood elements and may result in platelet activation. In the present work, these flow transients are mitigated using miniature vortex generator arrays that are embedded on the surface of the leaflets. Two vortex generator designs were investigated: one design comprised staggered rectangular fins and the other one staggered hemispheres. The closing transients in the absence and presence of the passive vortex generators are characterized using phase locked PIV measurements. The study utilizes a 25 mm St. Jude Medical valve placed in the aortic position of the Georgia Tech left heart simulator. Measurements of the velocity field in the center plane of the leaflets demonstrate that the dynamics of the transient vortices that precede the formation of the leakage jets can be significantly altered and controlled by relatively simple passive modifications of existing valve designs. Human blood experiments validated the effectiveness of miniature vortex generators in reducing thrombus formation by over 42 percent.

  16. Decision-making in aortic valve replacement: bileaflet mechanical valves versus stented bioprostheses

    PubMed Central

    Takkenberg, J.J.M.; Puvimanasinghe, J.P.A.; van Herwerden, L.A.; Eijkemans, M.J.C.; Steyerberg, E.W.; Habbema, J.D.F.; Bogers, A.J.J.C.

    2003-01-01

    Background Valve prosthesis selection for patients who require aortic valve replacement is dependent on several interrelated factors. Often, more than one valve type seems suitable for the individual patient and selection of a valve type may be difficult. Methods The application of an evidence-based microsimulation model as an objective tool to support the choice between a bileaflet mechanical prosthesis and a stented bioprosthesis in the individual patient is described. In addition, a pilot study investigating the effect of knowledge gained by this microsimulation model on prosthetic valve choice by cardiothoracic surgeons and cardiologists is presented for two hypothetical patients. Results After implantation of a mechanical valve, bleeding and thromboembolism are common, especially in the elderly. After implantation of a bioprosthesis, reoperation for structural failure is the most important valve-related complication, especially in younger patients. Life expectancy after aortic valve replacement is markedly reduced compared with the general Dutch age-matched population, regardless of the type of valve implanted. In the pilot study knowledge gained by the microsimulation model caused a shift in the preference towards a mechanical prosthesis in clinical experts. Conclusion Microsimulation incorporating current epidemiological data provides an objective tool to estimate prognosis for individual patients after aortic valve replacement with different valve prostheses. It may develop towards a useful clinical decision support system for valve prosthesis selection. ImagesFigure 6 PMID:25696138

  17. Simulations of pulsatile suspension flow through bileaflet mechanical heart valves to quantify platelet damage

    NASA Astrophysics Data System (ADS)

    Yun, Brian; Aidun, Cyrus; Yoganathan, Ajit

    2012-11-01

    Studies have shown that high shear stress and long exposure times on platelets have a strong impact on thromboembolic complications in bileaflet mechanical heart valves (BMHVs). This numerical study quantifies the platelet damage incurred in pulsatile flow through various BMHV designs. The lattice-Boltzmann method with external boundary force (LBM-EBF) was implemented to simulate pulsatile flow and capture the dynamics and surface shear stresses of modeled platelets with realistic geometry. The platelets are released in key regions of interest in the geometry as well as at various times of the cardiac cycle. The platelet damage is quantified using a linear shear stress-exposure time blood damage index (BDI) model. The multiscale computational method used to quantitatively measure the BDI during the pulsatile flow has been validated as being able to accurately capture bulk BMHV fluid flow and for accurately quantifying platelet damage in BMHV flows. These simulations will further knowledge of the geometric features and cardiac cycle times that most affect platelet damage. This study will ultimately lead to optimization of BMHV design in order to minimize thromboembolic complications.

  18. Mitigation of Shear-Induced Blood Damage of Mechanical Bileaflet Heart Valves using Embedded Vortex Generators

    NASA Astrophysics Data System (ADS)

    Hidalgo, Pablo; Arjunon, Sivakkumar; Saikrishnan, Neelakantan; Yoganathan, Ajit; Glezer, Ari

    2012-11-01

    The strong transitory shear stress generated during the time-periodic closing of the mechanical prosthetic bileaflet aortic heart valve, is considered to be one of the main factors responsible for complications, associated with thrombosis and thromboembolism. These flow transients are investigated using phase and time-averaged PIV in a low-volume (about 150 ml) test setup that simulates the pulsatile physiological conditions associated with a 23 mm St. Jude Medical valve. The PIV measurements are accompanied by continuous monitoring of the ventricular and aortic pressures and valve flow rate. Following the valve closure, the leakage flow between the valve leaflets is caused by the pressure buildup across the leaflets, leading to the formation of a regurgitation jet starting from the BMHV B-datum line. As in a typical starting jet, a counter-rotating vortex pair is formed along each leaflet edge and the vorticity sheet is associated with high shear stress that may be result in blood platelet activation. The present investigation demonstrates that the placement of arrays of mm-scale vortex generators near the edges of the leaflets diffuses the vortex sheet and suppresses the formation of these vortices, weakening the local velocity gradients and small-scale vortical structures. Supported by NIH and NSF.

  19. Three-Dimensional Fluid-Structure Interaction Simulation of Bileaflet Mechanical Heart Valve Flow Dynamics

    PubMed Central

    Cheng, Rui; Lai, Yong G.; Chandran, Krishnan B.

    2005-01-01

    The wall shear stress induced by the leaflet motion during the valve-closing phase has been implicated with thrombus initiation with prosthetic valves. Detailed flow dynamic analysis in the vicinity of the leaflets and the housing during the valve-closure phase is of interest in understanding this relationship. A three-dimensional unsteady flow analysis past bileaflet valve prosthesis in the mitral position is presented incorporating a fluid-structure interaction algorithm for leaflet motion during the valve-closing phase. Arbitrary Lagrangian–Eulerian method is employed for incorporating the leaflet motion. The forces exerted by the fluid on the leaflets are computed and applied to the leaflet equation of motion to predict the leaflet position. Relatively large velocities are computed in the valve clearance region between the valve housing and the leaflet edge with the resulting relatively large wall shear stresses at the leaflet edge during the impact-rebound duration. Negative pressure transients are computed on the surface of the leaflets on the atrial side of the valve, with larger magnitudes at the leaflet edge during the closing and rebound as well. Vortical flow development is observed on the inflow (atrial) side during the valve impact-rebound phase in a location central to the leaflet and away from the clearance region where cavitation bubbles have been visualized in previously reported experimental studies. PMID:15636108

  20. Numerical Investigation of the Performance of Three Hinge Designs of Bileaflet Mechanical Heart Valves

    PubMed Central

    Simon, Hélène A.; Ge, Liang; Sotiropoulos, Fotis

    2010-01-01

    Thromboembolic complications (TECs) of bileaflet mechanical heart valves (BMHVs) are believed to be due to the nonphysiologic mechanical stresses imposed on blood elements by the hinge flows. Relating hinge flow features to design features is, therefore, essential to ultimately design BMHVs with lower TEC rates. This study aims at simulating the pulsatile three-dimensional hinge flows of three BMHVs and estimating the TEC potential associated with each hinge design. Hinge geometries are constructed from micro-computed tomography scans of BMHVs. Simulations are conducted using a Cartesian sharp-interface immersed-boundary methodology combined with a second-order accurate fractional-step method. Leaflet motion and flow boundary conditions are extracted from fluid–structure-interaction simulations of BMHV bulk flow. The numerical results are analyzed using a particle-tracking approach coupled with existing blood damage models. The gap width and, more importantly, the shape of the recess and leaflet are found to impact the flow distribution and TEC potential. Smooth, streamlined surfaces appear to be more favorable than sharp corners or sudden shape transitions. The developed framework will enable pragmatic and cost-efficient preclinical evaluation of BMHV prototypes prior to valve manufacturing. Application to a wide range of hinges with varying design parameters will eventually help in determining the optimal hinge design. PMID:20571852

  1. A new approach to the analysis of Mira light curves

    NASA Technical Reports Server (NTRS)

    Mennessier, M. O.; Barthes, D.; Mattei, J. A.

    1990-01-01

    Two different but complementary methods for predicting Mira luminosities are presented. One method is derived from a Fourier analysis, it requires performing deconvolution, and its results are not certain due to the inherent instability of deconvolution problems. The other method is a learning method utilizing artificial intelligence techniques where a light curve is presented as an ordered sequence of pseudocycles, and rules are learned by linking the characteristics of several consecutive pseudocycles to one characteristic of the future cycle. It is observed that agreement between these methods is obtainable when it is possible to eliminate similar false frequencies from the preliminary power spectrum and to improve the degree of confidence in the rules.

  2. Edward Wheeler Hones Jr. (1922-2012)

    NASA Astrophysics Data System (ADS)

    Baker, Daniel N.; McPherron, Robert L.; Birn, Joachim

    2013-02-01

    Space physicist Edward Wheeler Hones Jr. died on 17 September 2012 at his home in Los Alamos, N. M. He was 90 years old. The cause of death was a heart attack that came following a brief hospitalization.

  3. Sturckow Recaps Last Shuttle Landing at Edwards

    NASA Video Gallery

    When Space Shuttle Discovery touched down at Edwards Air Force Base in Southern California on Sept. 11, 2009 to conclude mission STS-128, no one foresaw that it would be the last of 54 such landing...

  4. Brenda K. Edwards, PhD

    Cancer.gov

    Brenda K. Edwards, PhD, has been with the Surveillance Research Program (SRP) and its predecessor organizations at the National Cancer Institute (NCI) since 1989, serving as SRP’s Associate Director from 1990-2011.

  5. The Application of Bileaflet Mechanical Heart Valves in the Polish Ventricular Assist Device: Physical and Numerical Study and First Clinical Usage.

    PubMed

    Malota, Zbigniew; Sadowski, Wojciech; Krzyskow, Marek; Stolarzewicz, Bogdan

    2016-03-01

    The Polish ventricular assist device (Polvad) has been used successfully in clinical contexts for many years. The device contains two single-disc valves, one at the inlet and one at the outlet connector of the pneumatic pump. Unfortunately, in recent years, a problem has occurred with the availability of single-disc valves. This article presents the possibility of using bileaflet mechanical heart valve prostheses in the Polvad to avoid a discontinuity in clinical use. The study is based on experimental and numerical simulations and comparison of the distribution of flow, pressure, and stress (wall, shear, and turbulent) inside the Polvad chamber and the inlet/outlet connectors fitted with Sorin Monodisc and Sorin Bicarbon Fitline valves. The type and orientation of the inlet valve affects valve performance and flow distribution inside the chamber. Near-wall flow is observed for single-disc valves. In the case of bileaflet valves, the main jet is directed more centrally, with lower shear stress but higher turbulent stress in comparison with single-disc valves. For clinical usage, a 45° orientation of the bileaflet inlet valve was chosen, as this achieves good washing of the inlet area near the membrane paste surface. The Polvad with bileaflet valves has now been used successfully in our clinic for over a year and will continue to be used until new assist devices for heart support are developed. PMID:26365391

  6. Annual parallax measurements of a Mira variable star, U Lyncis

    NASA Astrophysics Data System (ADS)

    Kamezaki, Tatsuya; Nakagawa, Akiharu; Omodaka, Toshihiro; Handa, Toshihiro; Inoue, Kan-ichiro; Kurayama, Tomoharu; Kobayashi, Hideyuki; Nagayama, Takumi; Ueno, Yuji

    2015-06-01

    We have measured the annual parallax of the water maser around a Mira star, U Lyncis (U Lyn) with VLBI Exploration of Radio Astrometry (VERA). The value of the parallax is 1.27 ± 0.06 mas, corresponding to a distance of 786^{+40}_{-36}pc. This is the first VLBI measurement of the parallax of U Lyn. We obtained the period and the apparent magnitude of U Lyn based on near-infrared observations with the Kagoshima University 1 m telescope. The period and the mean magnitude of the K' band are 437.9 day and +1.15 ± 0.09 mag, respectively. Using our measured parallax and period, we find that the location of U Lyn on the period-luminosity plane is consistent with its nature as a Mira variable fundamental mode pulsator. Also, we estimated the distance using the period-luminosity relationship, our period and apparent magnitude and this gave a difference of about 100 pc between our parallactic distance and the distance estimated by using the period-luminosity relationship. We estimated the luminosity, radius, and mass of U Lyn to be 10100 ± 420 L⊙, 391 ± 34 R⊙, and 1.9 ± 0.7 M⊙, respectively. We found 50 water maser spots with a distribution ˜ 13 au around the star and the motion implies the existence of an outflow.

  7. Mg II line profiles of the Mira S Carinae

    SciTech Connect

    Bookbinder, J.A.; Brown, A.; Brugel, E.W.; Colorado Univ., Boulder )

    1989-07-01

    A series of high-dispersion IUE observations obtained to investigate the evolution of the shock structure of the Mira variable S Carinae have produced (despite limited phase coverage) a set of five exceptionally interesting spectra of the Mg II h and k lines. The two primary findings of these observations are (1) there is significant emission from both the h and k lines at positions corresponding to velocities of -150 km/s relative to the stellar photosphere and (2) the k/h flux ratio of the Mg II doublet remains below the theoretically predicted values which lie in the range 2:1 to 1:1 and shows a smooth dependence on the optical phase. Archival studies of other Miras (e.g., R Car) indicate that S Car is not unique in possessing unusual and highly variable Mg II h and k line profiles. Several possible physical processes that may explain these results, including radiative transfer effects in a shocked atmosphere, circumstellar scattering, and circumstellar absorption, are discussed. 10 refs.

  8. Mg II line profiles of the Mira S Carinae

    NASA Technical Reports Server (NTRS)

    Bookbinder, Jay A.; Brown, Alexander; Brugel, Edward W.

    1989-01-01

    A series of high-dispersion IUE observations obtained to investigate the evolution of the shock structure of the Mira variable S Carinae have produced (despite limited phase coverage) a set of five exceptionally interesting spectra of the Mg II h and k lines. The two primary findings of these observations are (1) there is significant emission from both the h and k lines at positions corresponding to velocities of -150 km/s relative to the stellar photosphere and (2) the k/h flux ratio of the Mg II doublet remains below the theoretically predicted values which lie in the range 2:1 to 1:1 and shows a smooth dependence on the optical phase. Archival studies of other Miras (e.g., R Car) indicate that S Car is not unique in possessing unusual and highly variable Mg II h and k line profiles. Several possible physical processes that may explain these results, including radiative transfer effects in a shocked atmosphere, circumstellar scattering, and circumstellar absorption, are discussed.

  9. Monitoring of Select Mira-Type Stars for Microvariability

    NASA Astrophysics Data System (ADS)

    Reiff, J. A.; Henson, G. D.

    2002-12-01

    We report here on continued efforts to detect and characterize the occurrence of microvariability in Mira-type stars. Broadband photometry in B, V, R, and I filters was performed on four stars suspected of exhibiting microvariability from an analysis of HIPPARCOS data by De Laverny et al. (1998, A & A). Light curves for these four stars (RR Boo, RX Mon, SV And, and X Crb) are provided for all observing nights between September 2001 and June 2002. Observations during summer 2001 of RR Boo detected one extremely large amplitude event near minimum light for the star (Guenther and Henson 2001, B.A.A.S.). However, observations of this star during 2002 detected no significant events with the star at brighter phases. The nature of detected variations for all stars in this sample and their relation to the phase of the stars' pulsation light curve is discussed as well as possible mechanisms for the cause of microvariability in Mira stars. This work has been supported by NSF grant AST-0097616 for the Southeastern Association for Astronomical Research (SARA) Research Experiences for Undergraduates program.

  10. STS-66 Edwards Landing Approach

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Atlantis approaches runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) 14 November 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to Earth and can be reused on

  11. STS-68 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Endeavour glides to a landing on runway 22 at Edwards, California, to complete the highly successful STS-68 mission dedicated to radar imaging of the earth's surface as part of NASA's Mission To Planet Earth program. The landing was at 10:02 a.m. (PDT) 11 October 1994, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather at Kennedy. The Endeavour crew was originally scheduled to land at Kennedy the morning of October 10, but mission planners decided early in the flight to extend the mission by one day. Mission commander was Michael A. Baker, making his third flight, and the pilot was Terrence W. Wilcutt, on his first mission. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the

  12. STS-64 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Space Shuttle Discovery settles to the main runway at Edwards, California, at 2:13 p.m. (PDT) 20 September 1994, to conclude mission STS-64. The spacecraft, with a crew of six, was launched into a 57-degree high inclination orbit from the Kennedy Space Center, Florida, at 3:23 p.m. (PDT), 9 September 1994. The mission featured the study of clouds and the atmosphere with a laser beaming system called Lidar In-Space Technology Experiment (LITE), and the first untethered space walk in over ten years. A Spartan satellite was also deployed and later retrieved in the study of the sun's corona and the solar wind. The mission was scheduled to end Sunday, 18 September, but was extended one day to continue science work. Bad weather at the Kennedy Space Center on September 19, forced a one-day delay to September 20, with a weather divert that day to Edwards. Mission commander was Richard Richards, the pilot Blaine Hammond, while mission specialists were Jerry Linenger, Susan Helms, Carl Meade, and Mark Lee. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders

  13. Shuttle Discovery Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The STS-29 Space Shuttle Discovery mission lands at NASA's then Ames-Dryden Flight Research Facility, Edwards AFB, California, early Saturday morning, 18 March 1989. Touchdown was at 6:35:49 a.m. PST and wheel stop was at 6:36:40 a.m. on runway 22. Controllers chose the concrete runway for the landing in order to make tests of braking and nosewheel steering. The STS-29 mission was very successful, completing the launch of a Tracking and Data Relay communications satellite, as well as a range of scientific experiments. Discovery's five-man crew was led by Commander Michael L. Coats, and included pilot John E. Blaha and mission specialists James P. Bagian, Robert C. Springer, and James F. Buchli. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout

  14. STS-68 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Endeavour glides to a landing on runway 22 at Edwards, California, to complete the highly successful STS-68 mission dedicated to radar imaging of the earth's surface as part of NASA's Mission To Planet Earth program. The landing was at 10:02 a.m. (PDT) 11 October 1994, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather at Kennedy. The Endeavour crew was originally scheduled to land at Kennedy the morning of October 10, but mission planners decided early in the flight to extend the mission by one day. Mission commander was Michael A. Baker, making his third flight, and the pilot was Terrence W. Wilcutt, on his first mission. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the

  15. STS-68 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The shuttle Endeavour comes in for a landing on runway 22 at Edwards, California, to complete the highly successful STS-68 mission dedicated to radar imaging of the earth's surface as part of NASA's Mission To Planet Earth program. The landing was at 10:02 a.m. (PDT) 11 October 1994, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather at Kennedy. The Endeavour crew was originally scheduled to land at Kennedy the morning of 10 October, but mission planners decided early in the flight to extend the mission by one day. Mission commander was Michael A. Baker making his third flight and the pilot was Terrence W. Wilcutt on his first mission. The four mission specialists were Thomas D. Jones, payload commander making his second flight; Steven L. Smith on his first flight; Daniel W. Bursch making his second flight; and Peter J.K. Wisoff making his second flight. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only

  16. STS-66 Edwards Landing Approach

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Atlantis approaches runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) 14 November 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to Earth and can be reused on

  17. Shuttle Atlantis Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1985-01-01

    NASA's Space Shuttle Atlantis touched down on the lakebed runway at Edwards Air Force Base in California's Mojave Desert Tuesday, 3 December 1985 at 1:33:49 p.m. Pacific Standard Time, concluding the STS 61-B international mission. The eight-day mission successfully deployed three communications satellites including the Mexican Morelos B, the Australian Aussat 2 and an RCA Satcom K-2 satellite. In addition, two spacewalks were performed to experiment with construction of structures in space. Crew of the 61-B mission included Commander Brewster H. Shaw, Jr.; Pilot Bryan D. O'Connor; Mission Specialists Mary L. Cleave, Sherwood C. Spring and Jerry L. Ross; and Payload Specialists Rudolfo Neri Vela of Mexico and Charles Walker of McDonnell Douglas Astronautics Co. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories

  18. STS-55 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Space Shuttle Columbia completes the STS-55 Spacelab D-2 mission 6 May with a landing at NASA's Ames-Dryden Flight Research Facility (later redesignated the Dryden Flight Research Center), Edwards, California, at 7:30 a.m. (PDT). The landing was scheduled for the Kennedy Space Center, Florida, but was diverted to Dryden during the final hours of flight because of unacceptable weather at the Florida facility. The STS-55 mission began with the launch from Kennedy at 7:50 a.m. (PDT), 26 April. Aboard Columbia were commander Steve Nagel; pilot Tom Henricks; mission specialists Jerry Ross, Charles Precourt, and Bernard Harris; and payload specialists Hans Schlegel and Ulrich Walter, both from Germany. During Columbia's flight the NASA space shuttle fleet logged more than one year of combined flight time in space, including the time of all previous orbiters and Columbia on this flight. That mark was reached at 7:01:42 (PDT) on 5 May, and with Columbia's landing the total flight time had reached 365 days, 23 hours, and 28 minutes. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles

  19. Shuttle Discovery Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The STS-29 Space Shuttle Discovery mission lands at NASA's then Ames-Dryden Flight Research Facility, Edwards AFB, California, early Saturday morning, 18 March 1989. Touchdown was at 6:35:49 a.m. PST and wheel stop was at 6:36:40 a.m. on runway 22. Controllers chose the concrete runway for the landing in order to make tests of braking and nosewheel steering. The STS-29 mission was very successful, completing the launch of a Tracking and Data Relay communications satellite, as well as a range of scientific experiments. Discovery's five-man crew was led by Commander Michael L. Coats, and included pilot John E. Blaha and mission specialists James P. Bagian, Robert C. Springer, and James F. Buchli. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout

  20. SiO MASERS IN ASYMMETRIC MIRAS. II. R CANCRI

    SciTech Connect

    Cotton, W. D.; Ragland, S.; Pluzhnik, E. A.; Danchi, W. C.; Traub, W. A.; Lacasse, M. G.

    2009-12-01

    This is the second paper in a series of multi-epoch observations of the SiO masers at 7 mm wavelength in several asymptotic giant branch stars from a sample of Mira variable stars showing evidence of asymmetric structure in the infrared. These stars have been observed interferometrically in the infrared by the Infrared Optical Telescope Array and with Very Long Baseline Array measurements of the SiO masers. In this paper, we present the observations of R Cancri (R Cnc). The systemic velocity of R Cnc is estimated to be 15.8 {+-} 0.2 km s{sup -1}. A comparison is made with the model calculations of Gray et al. which predict some but not all observed features.

  1. Variations of IR Spectra in carbon Mira, T Dra

    NASA Astrophysics Data System (ADS)

    Sung, H.-I.; Lee, S.-G.

    We have studied variations of physical parameters in the circumstellar envelope of carbon-rich Mira variable, T Dra, at different pulsation phases. After comparing the ISO/SWS spectra of T Dra with spectral energy distributions (SEDs) calculated in models, we could find the best fitted parameters for the physical state of the dust envelope at each phase. The variations of parameters, effective temperature, fraction of SiC grains, mass loss rates and inner radius of shell are found to have nearly the same trend as that of light curve. The other parameters, grain size, optical depth, radius of central star and dust temperature at the inner boundary of envelope, are inversely varing to the light curve. We have found that most physical parameters vary within factor 2, while mass loss rate varies more than factor 3 during pulsation period.

  2. Vanadium Oxide in the Spectra of Mira Variables

    NASA Astrophysics Data System (ADS)

    Castelaz, M. W.; Luttermoser, D. G.; Piontek, R. A.

    1999-05-01

    Over the last three years, we have made spectroscopic measurements of twenty Mira variable stars, as a function of phase, probing their stellar atmospheres and underlying pulsation mechanisms. Measurement of variations in TiO and VO with phase can be used to help determine whether these molecular species are produced in an extended region above the layers where Balmer line emission occurs or below this shocked region. Piontek & Luttermoser (1999 IAPPPC, submitted), produce synthetic spectra for three Mira variables, R Leo, V CVn, and R CVn as a function of phase. Comparison of their synthetic spectra to our observed spectra yield the fundamental astrophysical parameters of effective temperatures and surface gravities. Spectra are synthesized with LTE stellar stmospheres code ATLAS, using the 6.6--million Indiana University atomic and molecular line dataset. Piontek & Luttermoser point out that the IU dataset does not include vanadium oxide (VO). Thus, there is a noticeable difference between the synthetic spectra and observed near-IR spectra corresponding to the B-X bands of VO (Mahanti 1935, Proc. Phys. Soc., 47, 43; Keenan & Schroeder 1952,L. W., ApJ, 115, 82). In order to incorporate the VO bands in the synthetic spectra, we need to establish tables of wavenumbers, lowest energy levels, and oscillator strengths. Producing the tables is non-trivial. Laboratory measurements of wavenumbers are used in the Just-Overlapping Line Approximation (JOLA; Tsuji 1966, PASJ, 18, 127) to calculate oscillator strengths. The JOLA technique and preliminary results will be presented. MWC greatly appreciates support from the National Science Foundation grant AST-9500756. RAP acknowledges the Southeastern Association for Research in Astronomy 1998 Summer REU program supported by the National Science Foundation and thanks DGL for being his mentor.

  3. In Tribute: Senator Edward M. Kennedy, Friend of NIH

    MedlinePlus

    ... Javascript on. In Tribute: Senator Edward M. Kennedy, Friend of NIH Past Issues / Fall 2009 Table of ... NICHD) in Shriver's honor. Senator Edward M. Kennedy, Friend of NIH "… deep compassion for those in need." ...

  4. 11. Historic American Buildings Survey Seigfreid, Johnson, Edwards, Architects 1978 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Historic American Buildings Survey Seigfreid, Johnson, Edwards, Architects 1978 BRICKWORK DETAILS from the collection of Seigfreid, Johnson, Edwards, AIA Architects - Barrows-Coatsworth Building, 122 Main Street, Galena, Jo Daviess County, IL

  5. 10. Historic American Buildings Survey Seigfreid, Johnson, Edwards, Architects 1978 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Historic American Buildings Survey Seigfreid, Johnson, Edwards, Architects 1978 NORTHWEST ELEVATION from the collection of Seigfreid, Johnson, Edwards, AIA Architects - Barrows-Coatsworth Building, 122 Main Street, Galena, Jo Daviess County, IL

  6. Flow in a mechanical bileaflet heart valve at laminar and near-peak systole flow rates: CFD simulations and experiments.

    PubMed

    Ge, Liang; Leo, Hwa-Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P

    2005-10-01

    Time-accurate, fully 3D numerical simulations and particle image velocity laboratory experiments are carried out for flow through a fully open bileaflet mechanical heart valve under steady (nonpulsatile) inflow conditions. Flows at two different Reynolds numbers, one in the laminar regime and the other turbulent (near-peak systole flow rate), are investigated. A direct numerical simulation is carried out for the laminar flow case while the turbulent flow is investigated with two different unsteady statistical turbulence modeling approaches, unsteady Reynolds-averaged Navier-Stokes (URANS) and detached-eddy simulation (DES) approach. For both the laminar and turbulent cases the computed mean velocity profiles are in good overall agreement with the measurements. For the turbulent simulations, however, the comparisons with the measurements demonstrate clearly the superiority of the DES approach and underscore its potential as a powerful modeling tool of cardiovascular flows at physiological conditions. The study reveals numerous previously unknown features of the flow. PMID:16248308

  7. Prince Edward Island. Reference Series No. 33.

    ERIC Educational Resources Information Center

    Department of External Affairs, Ottawa (Ontario).

    This booklet, one of a series featuring the Canadian provinces, presents a brief overview of Prince Edward Island and is suitable for teacher reference or student reading. Separate sections discuss geography, climate, history, early trade, development, agriculture, the potato industry, forests, fisheries, aquaculture, industry, tourism, energy,…

  8. Edward Weston and the "Modern" Galvanometer Movement

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2008-01-01

    One of my favorite 19th century electrical scientists is Edward Weston, and one of my favorite devices for teaching the topics of electromagnetic forces and torques is the D'Arsonval galvanometer. The junction of these two topics is Weston's improved meter movement that has been used in analog meters for the past 125 years.

  9. Shuttle Atlantis Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1985-01-01

    NASA's Space Shuttle Atlantis touched down on the lakebed runway at Edwards Air Force Base in California's Mojave Desert Tuesday, 3 December 1985 at 1:33:49 p.m. Pacific Standard Time, concluding the STS 61-B international mission. The eight-day mission successfully deployed three communications satellites including the Mexican Morelos B, the Australian Aussat 2 and an RCA Satcom K-2 satellite. In addition, two spacewalks were performed to experiment with construction of structures in space. Crew of the 61-B mission included Commander Brewster H. Shaw, Jr.; Pilot Bryan D. O'Connor; Mission Specialists Mary L. Cleave, Sherwood C. Spring and Jerry L. Ross; and Payload Specialists Rudolfo Neri Vela of Mexico and Charles Walker of McDonnell Douglas Astronautics Co. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories

  10. STS-40 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Space Shuttle Columbia nears its touchdown on Runway 22 at Edwards, California, at 8:39 a.m., 14 June 1991, as the STS-40 life sciences mission comes to an end at NASA's Ames-Dryden Flight Research Facility (later redesignated Dryden Flight Research Center) after nine days of orbital flight. Aboard Columbia during the extended mission were Bryan D. O'Connor, mission commander; Sidney M. Gutierrez, pilot; mission specialists James P. Bagian, Tamara E. Jernigan, and Margaret Rhea Seddon; and payload specialists Francis Andrew Gaffney and Millie Hughes-Fulford. STS-40 was the first space shuttle mission dedicated to life sciences research to explore how the body reacts to a weightless environment and how it readjusts to gravity on return to earth. Columbia was launched on the STS-40 mission 5 June 1991, from Kennedy Space Center in Florida. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused

  11. STS-68 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A drag chute slows the shuttle Endeavour after landing on runway 22 at Edwards, California, to complete the highly successful STS-68 mission dedicated to radar imaging of the earth's surface as part of NASA's Mission To Planet Earth program. The landing was at 10:02 a.m. (PDT) 11 October 1994, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather at Kennedy. The Endeavour crew was originally scheduled to land at Kennedy the morning of 10 October, but mission planners decided early in the flight to extend the mission by one day. Mission commander was Michael A. Baker and the pilot was Terrence W. Wilcutt. The four mission specialists were Thomas D. Jones, payload; Steven L. Smith; Daniel W. Bursch; and Peter J.K. Wisoff. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific

  12. Shuttle Atlantis Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1988-01-01

    , provide facilities for several specialists to conduct experiments in such fields as medicine, astronomy, and materials manufacturing. Some types of satellites deployed by Space Shuttles include those involved in environmental and resources protection, astronomy, weather forecasting, navigation, oceanographic studies, and other scientific fields. The Space Shuttles can also launch spacecraft into orbits higher than the Shuttle's altitude limit through the use of Inertial Upper Stage (IUS) propulsion units. After release from the Space Shuttle payload bay, the IUS is ignited to carry the spacecraft into deep space. The Space Shuttles are also being used to carry elements of the International Space Station into space where they are assembled in orbit. The Space Shuttles were built by Rockwell International's Space Transportation Systems Division, Downey, California. Rockwell's Rocketdyne Division (now part of Boeing) builds the three main engines, and Thiokol, Brigham City, Utah, makes the solid rocket booster motors. Martin Marietta Corporation (now Lockheed Martin), New Orleans, Louisiana, makes the external tanks. Each orbiter (Space Shuttle) is 121 feet long, has a wingspan of 78 feet, and a height of 57 feet. The Space Shuttle is approximately the size of a DC-9 commercial airliner and can carry a payload of 65,000 pounds into orbit. The payload bay is 60 feet long and 15 feet in diameter. Each main engine is capable of producing a sea level thrust of 375,000 pounds and a vacuum (orbital) thrust of 470,000 pounds. The engines burn a mixture of liquid oxygen and liquid hydrogen. In orbit, the Space Shuttles circle the earth at a speed of 17,500 miles per hour with each orbit taking about 90 minutes. A Space Shuttle crew sees a sunrise or sunset every 45 minutes. When Space Shuttle flights began in April 1981, Dryden Flight Research Center, Edwards, California, was the primary landing site for the Shuttles. Now Kennedy Space Center, Florida, is the primary landing site

  13. STS-55 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Space Shuttle Columbia completes the STS-55 Spacelab D-2 mission 6 May with a landing at NASA's Ames-Dryden Flight Research Facility (later redesignated the Dryden Flight Research Center), Edwards, California, at 7:30 a.m. (PDT). The landing was scheduled for the Kennedy Space Center, Florida, but was diverted to Dryden during the final hours of flight because of unacceptable weather at the Florida facility. The STS-55 mission began with the launch from Kennedy at 7:50 a.m. (PDT), 26 April. Aboard Columbia were commander Steve Nagel; pilot Tom Henricks; mission specialists Jerry Ross, Charles Precourt, and Bernard Harris; and payload specialists Hans Schlegel and Ulrich Walter, both from Germany. During Columbia's flight the NASA space shuttle fleet logged more than one year of combined flight time in space, including the time of all previous orbiters and Columbia on this flight. That mark was reached at 7:01:42 (PDT) on 5 May, and with Columbia's landing the total flight time had reached 365 days, 23 hours, and 28 minutes. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles

  14. STS-68 Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The shuttle Endeavour comes in for a landing on runway 22 at Edwards, California, to complete the highly successful STS-68 mission dedicated to radar imaging of the earth's surface as part of NASA's Mission To Planet Earth program. The landing was at 10:02 a.m. (PDT) 11 October 1994, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather at Kennedy. The Endeavour crew was originally scheduled to land at Kennedy the morning of 10 October, but mission planners decided early in the flight to extend the mission by one day. Mission commander was Michael A. Baker making his third flight and the pilot was Terrence W. Wilcutt on his first mission. The four mission specialists were Thomas D. Jones, payload commander making his second flight; Steven L. Smith on his first flight; Daniel W. Bursch making his second flight; and Peter J.K. Wisoff making his second flight. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only

  15. DISCOVERY OF MIRA VARIABLE STARS IN THE METAL-POOR SEXTANS DWARF SPHEROIDAL GALAXY

    SciTech Connect

    Sakamoto, Tsuyoshi; Matsunaga, Noriyuki; Nakada, Yoshikazu; Hasegawa, Takashi

    2012-12-10

    We report the discovery of two Mira variable stars (Miras) toward the Sextans dwarf spheroidal galaxy (dSph). We performed optical long-term monitoring observations for two red stars in the Sextans dSph. The light curves of both stars in the I{sub c} band show large-amplitude (3.7 and 0.9 mag) and long-period (326 {+-} 15 and 122 {+-} 5 days) variations, suggesting that they are Miras. We combine our own infrared data with previously published data to estimate the mean infrared magnitudes. The distances obtained from the period-luminosity relation of the Miras (75.3{sup +12.8}{sub -10.9} and 79.8{sup +11.5}{sub -9.9} kpc, respectively), together with the radial velocities available, support memberships of the Sextans dSph (90.0 {+-} 10.0 kpc). These are the first Miras found in a stellar system with a metallicity as low as [Fe/H] {approx} -1.9 than any other known system with Miras.

  16. Laboratory evaluation of the COBAS MIRA S random access analyser.

    PubMed

    Kanluan, T; Intaramanee, S; Tangvarasittichai, S; Tangvarasittichai, O; Suwanton, L; Manochiopinij, S; Tantrarongroj, S; Leangphibul, P

    1991-01-01

    The random access analyser COBAS MIRA S (Roche Diagnostics) was evaluated for two months. The instrument is a computer-controlled discrete analyser which can be run in a combination profile and single test mode. This instrument has special features, including an automatic cuvette segment changer, a reagent rack cooling system, an external keyboard and monitor, as well as a bar-code facility for the entry of test parameters, worklists and sample identification numbers. Study of within-run and between-run precision gave values of % CV 0.54-3.37 and 0.61-3.65, respectively, for a variety of assays. Linearity testing to the upper limit of each test was also studied and were found to cover the necessary pathological range. Within the two-month period, no major problems were encountered. The instrument required minimum operator attention during operation. Correlation studies with the Hitachi 705 using six clinical chemistry tests (glucose, cholesterol, triglyceride, ALP, AST, ALT) gave correlation coefficients ranging from 0.95-0.99 and slopes of 0.91-1.17. PMID:18924890

  17. SIO MASERS IN ASYMMETRIC MIRAS. I. R LEONIS

    SciTech Connect

    Cotton, W. D.; Ragland, S.; Pluzhnik, E.; Danchi, W. C.; Traub, W. A.; Lacasse, M. G.

    2009-10-10

    This is the first paper in a series of multi-epoch observations of the SiO masers at 7 mm wavelength in several asymptotic giant branch (AGB) stars. This is a sample of Mira variable stars showing evidence of asymmetric structure in the infrared which were observed interferometrically in the infrared by Infrared Optical Telescope Array and with Very Long Baseline Array measurements of the SiO masers. In this paper, we present the observations of R Leonis (R Leo). During the period of observations, this star shows extended emission with large-scale coherent patterns in the radial velocity, possibly the result of ejecting a substantial amount of material, largely to the west. This is interpreted as an event in which material is expelled in a collimated flow, possibly following an energetic event. If common, these events may help explain the asymmetric nature of the planetary nebulae that develop from AGB stars. The systemic velocity of R Leo is estimated to be +1.0 +-0.3 km s{sup -1}. All observed radial velocities are well below the escape velocity.

  18. Robert Edwards: the path to IVF☆

    PubMed Central

    Johnson, Martin H

    2011-01-01

    The early influences on Robert Edwards’ approach to the scientific research that led to human IVF are described. His interest as a graduate student in the genetics of early mammalian development stimulated him later to investigate whether the origins of human genetic diseases such as Down, Klinefelter and Turner syndromes might be explained by events during egg maturation. This clinical problem provided the most powerful stimulus to achieve both oocyte maturation and fertilization in vitro in humans. Indeed, preimplantation genetic diagnosis was his main goal until he met Patrick Steptoe in 1968. A re-evaluation of his meeting with Steptoe suggests that initially Steptoe’s laparoscopic skill was of interest for its potential to solve the sperm capacitation problem. Steptoe’s impact on Edwards was twofold. First, Steptoe’s long-held interest in infertility raised this application of IVF higher in Edwards’ priorities. Second, Steptoe offered a long-term partnership, in which oocyte collection without in-vitro maturation was a possibility. The professional criticism generated by their work together encouraged Edwards to pursue a deliberate programme of public education about the issues raised and to challenge and develop professional bioethical thought and discourse about reproduction. The early life and career of Robert Edwards are described and re-evaluated in the light of documentary evidence. His early interest in the genetics of development provided the major motivation behind his goal of achieving IVF in humans. Through this work, he aimed to understand and hopefully to reduce the transmission of genetic disease in humans. His meeting with Patrick Steptoe, the details of which are re-examined, increased the significance for Edwards of infertility as an outcome of IVF. It also led to a creative long-term research partnership, initiated a long-term programme of public education in the UK about reproductive science and stimulated the development of

  19. Edward Teller Returns to LOS Alamos

    NASA Astrophysics Data System (ADS)

    Hecker, Siegfried S.

    2010-01-01

    I was asked to share some reflections of Edward Teller's return to Los Alamos during my directorship. I met Teller late in his life. My comments focus on that time and they will be mostly in the form of stories of my interactions and those of my colleagues with Teller. Although the focus of this symposium is on Teller's contributions to science, at Los Alamos it was never possible to separate Teller's science from policy and controversy ...

  20. 1995 Edward teller lecture. Patience and optimism

    NASA Astrophysics Data System (ADS)

    Miley, George H.

    1996-05-01

    Remarks made in the author's acceptance lecture for the 1995 Edward Teller Medal are presented and expanded. Topics covered include research on nuclear-pumped lasers, the first direct e-beam-pumped laser, direct energy conversion and advanced fuel fusion, plus recent work on inertial electrostatic confinement. ``Patience'' and ``optimism'' are viewed as essential elements needed by scientists following the ``zig-zag'' path to fusion energy production.

  1. A turbulent wake as a tracer of 30,000 years of Mira's mass loss history.

    PubMed

    Martin, D Christopher; Seibert, Mark; Neill, James D; Schiminovich, David; Forster, Karl; Rich, R Michael; Welsh, Barry Y; Madore, Barry F; Wheatley, Jonathan M; Morrissey, Patrick; Barlow, Tom A

    2007-08-16

    Mira is one of the first variable stars ever discovered and it is the prototype (and also the nearest example) of a class of low-to-intermediate-mass stars in the late stages of stellar evolution. These stars are relatively common and they return a large fraction of their original mass to the interstellar medium (ISM) (ref. 2) through a processed, dusty, molecular wind. Thus stars in Mira's stage of evolution have a direct impact on subsequent star and planet formation in their host galaxy. Previously, the only direct observation of the interaction between Mira-type stellar winds and the ISM was in the infrared. Here we report the discovery of an ultraviolet-emitting bow shock and turbulent wake extending over 2 degrees on the sky, arising from Mira's large space velocity and the interaction between its wind and the ISM. The wake is visible only in the far ultraviolet and is consistent with an unusual emission mechanism whereby molecular hydrogen is excited by turbulent mixing of cool molecular gas and shock-heated gas. This wind wake is a tracer of the past 30,000 years of Mira's mass-loss history and provides an excellent laboratory for studying turbulent stellar wind-ISM interactions. PMID:17700694

  2. Dust around Mira variables: An analysis of IRAS LRS spectra

    NASA Technical Reports Server (NTRS)

    Slijkhuis, S.

    1989-01-01

    The spatial extent and spectral appearance of the thin dust shell around Mira variables is determined largely by the dust absorptivity, Q(sub abs)(lambda), and the dust condensation temperature T(sub cond). Both Q(sub abs)(lambda) and T(sub cond) are extracted from IRAS low-resolution spectra (LRS) spectra. In order to do this, the assumption that the ratio of total power in the 10 micron feature to that in the 20 micron feature should be equal to that measured in other amorphous silicates (e.g., synthesized amorphous Mg2SiO4). It was found that T(sub cond) decreases with decreasing strength of the 10 micron feature, from T(sub cond) = 1000 K to 500 K (estimated error 20 percent). A value for the near-infrared dust absorptivity could not be determined. Although this parameter strongly affects the condensation radius, it hardly affects the shape of the LRS spectrum (as long as the optically thin approximation is valid), because it scales the spatial distribution of the dust. Information on the magnitude of the near-infrared dust absorptivity may be deduced from the unique carbon star BM Gem. This star has a LRS spectrum with silicate features indication an inner dust shell temperature of at least 1000 K. However, on the basis of observations in the 1920s-30s one may infer an inner dust shell radius of at least 6x10(exp 12)m. To have this high temperature at such a large distance, the near-infrared absorptivity of the dust must be high.

  3. Are the Current Doppler Echocardiography Criteria Able to Discriminate Mitral Bileaflet Mechanical Heart Valve Malfunction? An In Vitro Study.

    PubMed

    Evin, Morgane; Guivier-Curien, Carine; Pibarot, Philippe; Kadem, Lyes; Rieu, Régis

    2016-05-01

    Malfunction of bileaflet mechanical heart valves in the mitral position could either be due to patient-prosthesis mismatch (PPM) or leaflet obstruction. The aim of this article is to investigate the validity of current echocardiographic criteria used for diagnosis of mitral prosthesis malfunction, namely maximum velocity, mean transvalvular pressure gradient, effective orifice area, and Doppler velocity index. In vitro testing was performed on a double activation left heart duplicator. Both PPM and leaflet obstruction were investigated on a St. Jude Medical Master. PPM was studied by varying the St. Jude prosthesis size (21, 25, and 29 mm) and stroke volume (70 and 90 mL). Prosthesis leaflet obstruction was studied by partially or totally blocking the movement of one valve leaflet. Mitral flow conditions were altered in terms of E/A ratios (0.5, 1.0, and 1.5) to simulate physiologic panel of diastolic function. Maximum velocity, effective orifice area, and Doppler velocity index are shown to be insufficient to distinguish normal from malfunctioning St. Jude prostheses. Doppler velocity index and effective orifice area were 1.3 ± 0.49 and 1.83 ± 0.43 cm(2) for testing conditions with no malfunction below the 2.2 and 2 cm(2) thresholds (1.19 cm(2) for severe PPM and 1.23 cm(2) for fully blocked leaflet). The mean pressure gradient reached 5 mm Hg thresholds for several conditions of severe PPM only (6.9 mm Hg and mean maximum velocity value: 183.4 cm/s) whereas such value was never attained in the case of leaflet obstruction. In the case of leaflet obstruction, the maximum velocity averaged over the nine pulsed-wave Doppler locations increased by 38% for partial leaflet obstruction and 75% for a fully blocked leaflet when compared with normal conditions. Current echocardiographic criteria might be suboptimal for the detection of bileaflet mechanical heart valve malfunction. Further developments and investigations are required in order

  4. R Aquarii - The large-scale optical nebula and the Mira variable position

    NASA Technical Reports Server (NTRS)

    Michalitsianos, A. G.; Oliversen, R. J.; Hollis, J. M.; Kafatos, M.; Crull, H. E.

    1988-01-01

    The R Aquarii symbiotic star system is surrounded by a large-scale optical nebula. Observations of the nebular forbidden O III structure are presented and its morphological significance are discussed in context with previously observed small-scale radio-continuum features, which may be related. It is suggested that a precessing accretion disk may explain the global features of both the large-scale optical emission and the small-scale radio emission. Moreover, an accurate position has been determined of the system's Mira, which suggests that a recent theoretical model, yielding an egg-shaped central H II region for symbiotic systems with certain physical parameters, may apply to R Aquarii. The optical position of the 387 d period Mira variable is consistent with previous findings in the radio, that SiO maser emission is far removed from the Mira photosphere.

  5. DATA COLLECTION MANAGER MODULE OF REGION III'S MULTI-CRITERIA INTEGRATED RESOURCE ASSESSMENT (MIRA) ENVIRONMENTAL DECISION MAKING APPROACH

    EPA Science Inventory

    This proposal pertains to the on-going development of the Data Collection Manager (DCM) module, which is one of three modules that compose MIRA, Multi-criteria Integrated Resource Assessment. MIRA is Region III's newly conceived and continually developing decision support approac...

  6. 26. "AIR INSTALLATIONS; EDWARDS AIR FORCE BASE, CALIFORNIA; HIGH SPEED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. "AIR INSTALLATIONS; EDWARDS AIR FORCE BASE, CALIFORNIA; HIGH SPEED TEST TRACK." Drawing No. 10-259. One inch to 400 feet plan of original 10,000-foot sled track. No date. No D.O. series number. No headings as above. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  7. Blood damage through a bileaflet mechanical heart valve: a quantitative computational study using a multiscale suspension flow solver.

    PubMed

    Min Yun, B; Aidun, Cyrus K; Yoganathan, Ajit P

    2014-10-01

    Bileaflet mechanical heart valves (BMHVs) are among the most popular prostheses to replace defective native valves. However, complex flow phenomena caused by the prosthesis are thought to induce serious thromboembolic complications. This study aims at employing a novel multiscale numerical method that models realistic sized suspended platelets for assessing blood damage potential in flow through BMHVs. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through a 23 mm St. Jude Medical (SJM) Regent™ valve in the aortic position at very high spatiotemporal resolution with the presence of thousands of suspended platelets. Platelet damage is modeled for both the systolic and diastolic phases of the cardiac cycle. No platelets exceed activation thresholds for any of the simulations. Platelet damage is determined to be particularly high for suspended elements trapped in recirculation zones, which suggests a shift of focus in blood damage studies away from instantaneous flow fields and toward high flow mixing regions. In the diastolic phase, leakage flow through the b-datum gap is shown to cause highest damage to platelets. This multiscale numerical method may be used as a generic solver for evaluating blood damage in other cardiovascular flows and devices. PMID:25070372

  8. The effect of implantation orientation of a bileaflet mechanical heart valve on kinematics and hemodynamics in an anatomic aorta.

    PubMed

    Borazjani, Iman; Sotiropoulos, Fotis

    2010-11-01

    We carry out three-dimensional high-resolution numerical simulations of a bileaflet mechanical heart valve under physiologic pulsatile flow conditions implanted at different orientations in an anatomic aorta obtained from magnetic resonance imaging (MRI) of a volunteer. We use the extensively validated for heart valve flow curvilinear-immersed boundary (CURVIB) fluid-structure interaction (FSI) solver in which the empty aorta is discretized with a curvilinear, aorta-conforming grid while the valve is handled as an immersed boundary. The motion of the valve leaflets are calculated through a strongly coupled FSI algorithm implemented in conjunction with the Aitken convergence acceleration technique. We perform simulations for three valve orientations, which differ from each other by 45 deg and compare the results in terms of leaflet motion and flow field. We show that the valve implanted symmetrically relative to the symmetry plane of the ascending aorta curvature exhibits the smallest overall asymmetry in the motion of its two leaflets and lowest rebound during closure. Consequently, we hypothesize that this orientation is beneficial to reduce the chance of intermittent regurgitation. Furthermore, we find that the valve orientation does not significantly affect the shear stress distribution in the aortic lumen, which is in agreement with previous studies. PMID:21034146

  9. Device Thrombogenicty Emulator (DTE) – Design optimization Methodology for Cardiovascular Devices: A Study in Two Bileaflet MHV Designs

    PubMed Central

    Xenos, Michalis; Girdhar, Gaurav; Alemu, Yared; Jesty, Jolyon; Slepian, Marvin; Einav, Shmuel; Bluestein, Danny

    2010-01-01

    Patients who receive prosthetic heart valve (PHV) implants require mandatory anticoagulation medication after implantation due to the thrombogenic potential of the valve. Optimization of PHV designs may facilitate reduction of flow-induced thrombogenicity and reduce or eliminate the need for post-implant anticoagulants. We present a methodology entitled Device Thrombogenicty Emulator (DTE) for optimizing the thrombo-resistance performance of PHV by combining numerical and experimental approaches. Two bileaflet mechanical heart valves (MHV) designs – St. Jude Medical (SJM) and ATS were investigated, by studying the effect of distinct flow phases on platelet activation. Transient turbulent and direct numerical simulations (DNS) were conducted, and stress loading histories experienced by the platelets were calculated along flow trajectories. The numerical simulations indicated distinct design dependent differences between the two valves. The stress-loading waveforms extracted from the numerical simulations were programmed into a hemodynamic shearing device (HSD), emulating the flow conditions past the valves in distinct ‘hot spot’ flow regions that are implicated in MHV thrombogenicity. The resultant platelet activity was measured with a modified prothrombinase assay, and was found to be significantly higher in the SJM valve, mostly during the regurgitation phase. The experimental results were in excellent agreement with the calculated platelet activation potential. This establishes the utility of the DTE methodology for serving as a test bed for evaluating design modifications for achieving better thrombogenic performance for such devices. PMID:20483411

  10. Experimental investigation of the flow field past a bileaflet mechanical heart valve in pulsatile flow within an anatomical aorta model

    NASA Astrophysics Data System (ADS)

    Brown, Laura; Tavoularis, Stavros

    2011-11-01

    A bileaflet mechanical heart valve (BMHV) has been mounted at the inlet of an anatomical model of the human aorta, and placed within a mock circulation loop that simulates physiological flow conditions. The working fluid matches the refractive index of silicone, from which the aorta model and other parts of the test section are made, and the viscosity of blood. Flow characteristics past the BMHV are measured using stereoscopic and planar particle image velocimetry and laser Doppler velocimetry. In contrast to previous experiments, in which heart valves have been tested in simplified aortic geometries, this arrangement permits the study of the dependence of flow past the valve upon recirculation in the sinuses of Valsalva, the flow rate through the coronary arteries, and the aorta curvature. The effect of valve orientation will also be investigated with the objective to determine a hemodynamically optimal configuration with potential benefits to implantation procedures. The measured viscous shear stress distribution will be analyzed towards predicting the initiation of thrombosis in patients and identifying regions of stagnation, which could facilitate thrombus attachment.

  11. Simulation of the three-dimensional hinge flow fields of a bileaflet mechanical heart valve under aortic conditions.

    PubMed

    Simon, Hélène A; Ge, Liang; Borazjani, Iman; Sotiropoulos, Fotis; Yoganathan, Ajit P

    2010-03-01

    Thromboembolic complications of bileaflet mechanical heart valves (BMHV) are believed to be due to detrimental stresses imposed on blood elements by the hinge flows. Characterization of these flows is thus crucial to identify the underlying causes for complications. In this study, we conduct three-dimensional pulsatile flow simulations through the hinge of a BMHV under aortic conditions. Hinge and leaflet geometries are reconstructed from the Micro-Computed Tomography scans of a BMHV. Simulations are conducted using a Cartesian sharp-interface immersed-boundary methodology combined with a second-order accurate fractional-step method. Physiologic flow boundary conditions and leaflet motion are extracted from the Fluid-Structure Interaction simulations of the bulk of the flow through a BMHV. Calculations reveal the presence, throughout the cardiac cycle, of flow patterns known to be detrimental to blood elements. Flow fields are characterized by: (1) complex systolic flows, with rotating structures and slow reverse flow pattern, and (2) two strong diastolic leakage jets accompanied by fast reverse flow at the hinge bottom. Elevated shear stresses, up to 1920 dyn/cm2 during systole and 6115 dyn/cm2 during diastole, are reported. This study underscores the need to conduct three-dimensional simulations throughout the cardiac cycle to fully characterize the complexity and thromboembolic potential of the hinge flows. PMID:19960368

  12. The Effect of Implantation Orientation of a Bileaflet Mechanical Heart Valve on Kinematics and Hemodynamics in an Anatomic Aorta

    PubMed Central

    Borazjani, Iman; Sotiropoulos, Fotis

    2011-01-01

    We carry out three-dimensional high-resolution numerical simulations of a bileaflet mechanical heart valve under physiologic pulsatile flow conditions implanted at different orientations in an anatomic aorta obtained from magnetic resonance imaging (MRI) of a volunteer. We use the extensively validated for heart valve flow curvilinear-immersed boundary (CURVIB) fluid-structure interaction (FSI) solver in which the empty aorta is discretized with a curvilinear, aorta-conforming grid while the valve is handled as an immersed boundary. The motion of the valve leaflets are calculated through a strongly coupled FSI algorithm implemented in conjunction with the Aitken convergence acceleration technique. We perform simulations for three valve orientations, which differ from each other by 45 deg and compare the results in terms of leaflet motion and flow field. We show that the valve implanted symmetrically relative to the symmetry plane of the ascending aorta curvature exhibits the smallest overall asymmetry in the motion of its two leaflets and lowest rebound during closure. Consequently, we hypothesize that this orientation is beneficial to reduce the chance of intermittent regurgitation. Furthermore, we find that the valve orientation does not significantly affect the shear stress distribution in the aortic lumen, which is in agreement with previous studies. PMID:21034146

  13. CFD simulation of a novel bileaflet mechanical heart valve prosthesis: an estimation of the Venturi passage formed by the leaflets.

    PubMed

    Yokoyama, Y; Medart, D; Hormes, M; Schmitz, C; Hamilton, K; Kwant, P B; Takatani, S; Schmitz-Rode, T; Steinseifer, U

    2006-12-01

    The aim of this study was to validate the flow characteristics of the novel Helmholtz-Institute Aachen Bileaflet (HIA-BL) heart valve prosthesis. The curved leaflets of the HIA-BL valve form a Venturi passage between the leaflets at peak systole. By narrowing the cross section the flow accelerates and the static pressure at the central passage decreases according to the Venturi effect. The low-pressure zone between the leaflets is expected to stabilize the leaflets in fully open position at peak systole. To investigate the Venturi passage, the flow fields of two valve geometries were investigated by CFD (Computational Fluid Dynamics): one geometry exhibits curved leaflets resulting in a Venturi passage; the other geometry features straight leaflets. The flow profiles, pressure distribution and resulting torque of both passages were compared and investigated. Although flow profiles downstream of both valves were similar, the flow passages between the leaflets were different for the investigated leaflet geometries. The straight leaflet passage showed a large boundary layer separation zone near the leaflets and the lowest pressure at the leading edge of the leaflet. The Venturi passage showed a reduction of the boundary layer separation zones and the lowest pressure between the leaflets could be found in the narrowest flow cross section of the Venturi passage. Additionally, the resulting torque showed that the Venturi passage produced an opening momentum. The results demonstrate that the Venturi passage stabilizes the leaflets in open position at peak systole. PMID:17219353

  14. Ethical reflections on Edward Jenner's experimental treatment.

    PubMed

    Davies, Hugh

    2007-03-01

    In 1798 Dr Edward Jenner published his famous account of "vaccination". Some claim that a Research Ethics Committee, had it existed in the 1790s, might have rejected his work. I provide the historical context of his work and argue that it addressed a major risk to the health of the community, and, given the devastating nature of smallpox and the significant risk of variolation, the only alternative preventative measure, Jenner's study had purpose, justification and a base in the practice of the day. PMID:17329392

  15. 1995 Edward teller lecture. Patience and optimism

    SciTech Connect

    Miley, G.H.

    1996-05-01

    Remarks made in the author{close_quote}s acceptance lecture for the 1995 Edward Teller Medal are presented and expanded. Topics covered include research on nuclear-pumped lasers, the first direct e-beam-pumped laser, direct energy conversion and advanced fuel fusion, plus recent work on inertial electrostatic confinement. {open_quote}{open_quote}Patience{close_quote}{close_quote} and {open_quote}{open_quote}optimism{close_quote}{close_quote} are viewed as essential elements needed by scientists following the {open_quote}{open_quote}zig-zag{close_quote}{close_quote} path to fusion energy production. {copyright} {ital 1996 American Institute of Physics.}

  16. STS-66 Atlantis Landing Approach at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Space Shuttle Atlantis approaches runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) November 14, 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather.

  17. Carbon and Oxygen Isotopic Ratios for Nearby Miras

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth H.; Lebzelter, Thomas; Straniero, Oscar

    2016-07-01

    Carbon and oxygen isotopic ratios are reported for a sample of 46 Mira and SRa-type variable asymptotic giant branch (AGB) stars. Vibration–rotation first and second-overtone CO lines in 1.5–2.5 μm spectra were measured to derive isotopic ratios for 12C/13C, 16O/17O, and 16O/18O. Comparisons with previous measurements for individual stars and with various samples of evolved stars, as available in the extant literature, are discussed. Models for solar composition AGB stars of different initial masses are used to interpret our results. We find that the majority of M-stars have main sequence masses ≤2 M ⊙ and have not experienced sizable third dredge-up (TDU) episodes. The progenitors of the four S-type stars in our sample are slightly more massive. Of the six C-stars in the sample three have clear evidence relating their origin to the occurrence of TDU. Comparisons with O-rich presolar grains from AGB stars that lived before the formation of the solar system reveal variations in the interstellar medium chemical composition. The present generation of low-mass AGB stars, as represented by our sample of long period variables (LPVs), shows a large spread of 16O/17O ratios, similar to that of group 1 presolar grains and in agreement with theoretical expectations for the composition of mass 1.2–2 M ⊙ stars after the first dredge-up. In contrast, the 16O/18O ratios of present-day LPVs are definitely smaller than those of group 1 grains. This is most probably a consequence of the the decrease with time of the 16O/18O ratio in the interstellar medium due to the chemical evolution of the Milky Way. One star in our sample has an O composition similar to that of group 2 presolar grains originating in an AGB star undergoing extra-mixing. This may indicate that the extra-mixing process is hampered at high metallicity, or, equivalently, favored at low metallicity. Similarly to O-rich grains, no star in our sample shows evidence of hot bottom burning, which is expected

  18. Robert Edwards: the path to IVF.

    PubMed

    Johnson, Martin H

    2011-08-01

    The early influences on Robert Edwards’ approach to the scientific research that led to human IVF are described. His interest as a graduate student in the genetics of early mammalian development stimulated him later to investigate whether the origins of human genetic diseases such as Down, Klinefelter and Turner syndromes might be explained by events during egg maturation. This clinical problem provided the most powerful stimulus to achieve both oocyte maturation and fertilization in vitro in humans. Indeed,preimplantation genetic diagnosis was his main goal until he met Patrick Steptoe in 1968. A re-evaluation of his meeting with Steptoe suggests that initially Steptoe’s laparoscopic skill was of interest for its potential to solve the sperm capacitation problem. Steptoe’simpact on Edwards was twofold. First, Steptoe’s long-held interest in infertility raised this application of IVF higher in Edwards’priorities. Second, Steptoe offered a long-term partnership, in which oocyte collection without in-vitro maturation was a possibility.The professional criticism generated by their work together encouraged Edwards to pursue a deliberate programme of public education about the issues raised and to challenge and develop professional bioethical thought and discourse about reproduction. PMID:21680248

  19. Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

    PubMed

    Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

    2016-03-01

    To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is <90 beats/min; however, these values significantly increase in the St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as

  20. The age and structure of the Galactic bulge from Mira variables

    NASA Astrophysics Data System (ADS)

    Catchpole, Robin M.; Whitelock, Patricia A.; Feast, Michael W.; Hughes, Shaun M. G.; Irwin, Mike; Alard, Christophe

    2016-01-01

    We report periods and JHKL observations for 643 oxygen-rich Mira variables found in two outer bulge fields at b = -7° and l = ±8° and combine these with data on 8057 inner bulge Miras from the Optical Gravitational Lensing Experiment, MACHO and Two Micron All Sky Survey surveys, which are concentrated closer to the Galactic Centre. Distance moduli are estimated for all these stars. Evidence is given showing that the bulge structure is a function of age. The longer period Miras (log P > 2.6, age ˜5 Gyr and younger) show clear evidence of a bar structure inclined to the line of sight in both the inner and outer regions. The distribution of the shorter period (metal-rich globular cluster age) Miras appears spheroidal in the outer bulge. In the inner region these old stars are also distributed differently from the younger ones and possibly suggest a more complex structure. These data suggest a distance to the Galactic Centre, R0, of 8.9 kpc with an estimated uncertainty of ˜0.4 kpc. The possible effect of helium enrichment on our conclusions is discussed.

  1. Search for surface magnetic fields in Mira stars: first results on χ Cyg

    NASA Astrophysics Data System (ADS)

    Lèbre, Agnès; Aurière, Michel; Fabas, Nicolas; Gillet, Denis; Herpin, Fabrice; Petit, Pascal; Konstantinova-Antova, Renada

    2014-08-01

    So far, surface magnetic fields have never been reported on Mira stars, while observational facilities allowing detection and measurement of weak surface fields through the Zeeman effect have become available. Then, in order to complete the knowledge of the magnetic field and of its influence during the transition from Asymptotic Giant Branch (AGB) to Planetary Nebulae (PN) stages, we have undertaken a search for magnetic fields at the surface of Miras. We present the first spectropolarimetric observations (performed with the Narval instrument at Télescope Bernard Lyot-TBL, Pic du Midi, France) of the S-type Mira star χ Cyg. We have detected a polarimetric signal in the Stokes V spectra and we have established its Zeeman origin. We claim that it is likely to be related to a weak magnetic field present at the photospheric level and in the lower part of the stellar atmosphere. The origin of this magnetic field is discussed in the framework of shock waves periodically propagating throughout the atmosphere of a Mira.

  2. An Analysis of Retention and Attrition at MiraCosta College.

    ERIC Educational Resources Information Center

    Baker, Ronald

    A study was conducted at MiraCosta College (MCC), in Del Mar, California, to investigate various aspects of retention and attrition and to make recommendations for possible program enhancements. The study sought to determine when students drop out of classes, which students drop out of school completely, and the drop out rate for various…

  3. The Chromosphere/Shock Dilemma of Non-Mira, Late-Type Variable Stars

    NASA Technical Reports Server (NTRS)

    Willson, Lee Anne

    1997-01-01

    An investigation of the atmospheric structure of non-Mira, asymptotic giant branch stars through NLTE radiative transfer modeling applied to hydrodynamic models is discussed. Synthetic spectra resulting from these calculations were compared with IUE observations of these stars to test the validity of the models. The development of the hydrodynamic models is detailed.

  4. Efficacy of Edwards' Cognitive Shift Approach to Art Education.

    ERIC Educational Resources Information Center

    Chambliss, Catherine A.; Hartl, Alan J.

    1987-01-01

    Noting the lack of experimental evidence substantiating the efficacy of educational strategies designed to exploit the right hemisphere of the brain, a study was designed to assess the cognitive shift model of the Edwards' training procedure. Results showed no difference between the Edwards' procedure and a placebo procedure. Implications for the…

  5. Edward F. Diener: Award for Distinguished Scientific Contributions

    ERIC Educational Resources Information Center

    American Psychologist, 2012

    2012-01-01

    Presents Edward F. Diener as one of the winners of the American Psychological Association's Award for Distinguished Scientific Contributions (2012). Edward F. Diener has been a leader in every aspect of well-being research. He provided an influential conception of well-being as consisting of cognitive and emotional elements. A citation, biography,…

  6. 76 FR 76710 - Baine, Edward H.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Baine, Edward H.; Notice of Filing Take notice that on December 1, 2011, Edward H. Baine submitted for filing, an application for authority to hold interlocking...

  7. Modelling of dust around the symbiotic Mira RR Telescopii during obscuration epochs

    NASA Astrophysics Data System (ADS)

    Jurkic, T.; Kotnik-Karuza, D.

    2012-08-01

    Context. Symbiotic Miras represent a class of peculiar binaries whose nature is still not well understood. Physical properties of the circumstellar dust and associated physical mechanisms play an important role in understanding the evolution of symbiotic binaries and the interaction between their components. We present a model of inner dust regions around the cool Mira component of the symbiotic nova RR Tel based on the near-IR terrestrial photometry and infrared ISO spectra. Aims: Our goal is to find a comprehensive and consistent model of the circumstellar inner dust regions around the Mira component that can explain the observed photometric and spectroscopic features in the near- and mid-infrared. Methods: Available JHKL photometric observations from South African Astronomical Observatory were collected and corrected for Mira pulsations as well as for interstellar reddening to follow temporal changes of the near-infrared colours. Spectral energy distributions (SEDs) from 1 to 13 μm during obscuration epoch were reconstructed with the simultaneously available ISO/SWS spectra and JHKL magnitudes. The dust properties were determined by modelling both the reconstructed SEDs and the near-IR colours using the DUSTY numerical code. This 1D code solves radiative transfer through the circumstellar dust by calculating the dust temperature profile assuming spherical symmetry. Results: The Mira pulsation period of 387 days was found and confirmed with two independent fitting methods. A long-term variation of ~7000 days, which cannot be attributed to orbital motion, was obtained from the analysis of the near-IR magnitudes. Reconstructed infrared SEDs were modelled successfully by a single dust shell with dust distribution enhanced by radiatively driven stellar winds. Mira temperature, dust sublimation temperature, grain diameter, density distribution, and optical depth have been obtained. Our model shows a maximum dust grain diameter of 4 μm, which is larger than expected

  8. STS-4 landing at Edwards Air Foce Base, California

    NASA Technical Reports Server (NTRS)

    1982-01-01

    STS-4 landing at Edwards Air Foce Base, California. Actor Roy Rogers with Astronauts Jerry L. Ross, left, and Guy S. Gardner at Edwards for the STS-4 landing on July 1, 1982. Also present (behind Gardner at extreme right) was former Astronaut Edwin E. Aldrin, Jr. (33226); President Ronald Reagan and First Lady Nancy Reagan meet Astronauts Thomas K. Mattingly, II., right, and Henry W. Hartsfield, Jr., after the landing of the Columbia at Edwards (33227,33230); Space Shuttle Columbia, followed by two T-38 chase planes, touches down on Edwards Air Force Base's Runway 22 to complete mission. In this view, one chase plane appears to be directly above and behind the Columbia, whose nose wheels have not yet touched ground. The other plane appears to be further up front (33228); The rear wheels of the Columbia touch down on the Edwards AFB runway. There are no chase planes in sight in this photo (33229).

  9. Modelling the atmosphere of the carbon-rich Mira RU Virginis

    NASA Astrophysics Data System (ADS)

    Rau, G.; Paladini, C.; Hron, J.; Aringer, B.; Groenewegen, M. A. T.; Nowotny, W.

    2015-11-01

    Context. We study the atmosphere of the carbon-rich Mira RU Vir using the mid-infrared high spatial resolution interferometric observations from VLTI/MIDI. Aims: The aim of this work is to analyse the atmosphere of the carbon-rich Mira RU Vir with hydrostatic and dynamic models, in this way deepening the knowledge of the dynamic processes at work in carbon-rich Miras. Methods: We compare spectro-photometric and interferometric measurements of this carbon-rich Mira AGB star with the predictions of different kinds of modelling approaches (hydrostatic model atmospheres plus MOD-More Of Dusty, self-consistent dynamic model atmospheres). A geometric model fitting tool is used for a first interpretation of the interferometric data. Results: The results show that a joint use of different kinds of observations (photometry, spectroscopy, interferometry) is essential for shedding light on the structure of the atmosphere of a carbon-rich Mira. The dynamic model atmospheres fit the ISO spectrum well in the wavelength range λ = [2.9,25.0] μm. Nevertheless, a discrepancy is noticeable both in the SED (visible) and in the interferometric visibilities (shape and level), which is a possible explanation are intra-/inter-cycle variations in the dynamic model atmospheres, as well as in the observations. The presence of a companion star and/or a disk or a decrease in mass loss within the past few hundred years cannot be excluded, but these explanations are considered unlikely. Based on observations made with ESO telescopes at La Silla Paranal Observatory under programme IDs: 085.D-0756 and 093. D-0708.Appendix A is available in electronic form at http://www.aanda.org

  10. Multiepoch Interferometric Study of Mira Variables. I. Narrowband Diameters of RZ Pegasi and S Lacertae

    NASA Astrophysics Data System (ADS)

    Thompson, R. R.; Creech-Eakman, M. J.; van Belle, G. T.

    2002-09-01

    As part of the long-term monitoring of Mira variables at the Palomar Testbed Interferometer, we report high-resolution narrowband angular sizes of the oxygen-rich Mira S Lac and the carbon-rich Mira RZ Peg in the near-infrared. The data set spans three pulsation cycles for S Lac and two pulsation cycles for RZ Peg (a total of 1070 25 s observations) and represents the first study to correlate multiepoch narrowband interferometric data of Mira variables. When the calibrated visibility data are fitted using a uniform disk brightness model, differences are seen in their angular diameters as a function of wavelength within the K band (2.0-2.4 μm), the source of which is believed to be molecular absorptions in or above the photospheres of the two chemically different Miras. Using visible photometric data provided by the Association Francaise des Observateurs d'Etoiles Variables (AFOEV), the continuum minimum size of RZ Peg lags this by 0.28+/-0.02 in pulsation, similar to the phase lag found in Correlation Radial Velocities (CORAVEL) data. However, for S Lac, the continuum minimum size tracks the visual maximum brightness. Based on the mean of the continuum angular diameter cycloids, basic stellar parameters are computed for both RZ Peg and S Lac, with both showing maximum atmospheric extension with respect to the 2.0 and 2.4 μm diameters near phase 0.9. Using the mean value of the fitted cycloids, RZ Peg has a radius Rmean=377+/-111 Rsolar and a mean Teff=2706+/-36 K; S Lac has a radius Rmean=292+/-73 Rsolar and a mean Teff=2605+/-47 K. The dominant source of error in the radii is the large uncertainty in the distances to these two stars.

  11. STS-106 Crew Interviews: Edward T. Lu

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Live footage of a preflight interview with Mission Specialist Edward T. Lu is seen. The interview addresses many different questions including why Lu became interested in the space program, the events that led to his interest, the transition from an engineer to research scientist, and finally to getting selected into the astronaut program. Other interesting information that this one-on-one interview discusses are the main goals of the STS-106 mission, its scheduled docking with the new International Space Station (ISS), making the Zvezda Service Module ready for entrance, and crew training both in the United States and Russia. Lu mentions his responsibilities during the much-anticipated docking as well as his scheduled space-walk with Yuri Ivanovich Malenchenko. Lu also discusses the use of the Robotic Arm during his space-walk, installation of a magnetometer on the Zvezda Module, and work that will have to take place inside the Service Module.

  12. Edward jenner and the small pox vaccine.

    PubMed

    Smith, Kendall A

    2011-01-01

    Edward Jenner, who discovered that it is possible to vaccinate against Small Pox using material from Cow Pox, is rightly the man who started the science of immunology. However, over the passage of time many of the details surrounding his astounding discovery have been lost or forgotten. Also, the environment within which Jenner worked as a physician in the countryside, and the state of the art of medicine and society are difficult to appreciate today. It is important to recall that people were still being bled at the time, to relieve the presence of evil humors. Accordingly, this review details Jenner's discovery and attempts to place it in historical context. Also, the vaccine that Jenner used, which decreased the prevalence of Small Pox worldwide in his own time, and later was used to eradicate Small Pox altogether, is discussed in light of recent data. PMID:22566811

  13. MD-11 PCA - First Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This McDonnell Douglas MD-11 transport aircraft approaches its first landing under engine power only on Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

  14. MD-11 PCA - First Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This McDonnell Douglas MD-11 approaches the first landing ever of a transport aircraft under engine power only on Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when it normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

  15. Comparison of hinge microflow fields of bileaflet mechanical heart valves implanted in different sinus shape and downstream geometry.

    PubMed

    Kuan, Yee Han; Kabinejadian, Foad; Nguyen, Vinh-Tan; Su, Boyang; Yoganathan, Ajit P; Leo, Hwa Liang

    2015-01-01

    The characterization of the bileaflet mechanical heart valves (BMHVs) hinge microflow fields is a crucial step in heart valve engineering. Earlier in vitro studies of BMHV hinge flow at the aorta position in idealized straight pipes have shown that the aortic sinus shapes and sizes may have a direct impact on hinge microflow fields. In this paper, we used a numerical study to look at how different aortic sinus shapes, the downstream aortic arch geometry, and the location of the hinge recess can influence the flow fields in the hinge regions. Two geometric models for sinus were investigated: a simplified axisymmetric sinus and an idealized three-sinus aortic root model, with two different downstream geometries: a straight pipe and a simplified curved aortic arch. The flow fields of a 29-mm St Jude Medical BMHV with its four hinges were investigated. The simulations were performed throughout the entire cardiac cycle. At peak systole, recirculating flows were observed in curved downsteam aortic arch unlike in straight downstream pipe. Highly complex three-dimensional leakage flow through the hinge gap was observed in the simulation results during early diastole with the highest velocity at 4.7 m/s, whose intensity decreased toward late diastole. Also, elevated wall shear stresses were observed in the ventricular regions of the hinge recess with the highest recorded at 1.65 kPa. Different flow patterns were observed between the hinge regions in straight pipe and curved aortic arch models. We compared the four hinge regions at peak systole in an aortic arch downstream model and found that each individual hinge did not vary much in terms of the leakage flow rate through the valves. PMID:25343223

  16. Computational simulations of flow dynamics and blood damage through a bileaflet mechanical heart valve scaled to pediatric size and flow.

    PubMed

    Yun, B Min; McElhinney, Doff B; Arjunon, Shiva; Mirabella, Lucia; Aidun, Cyrus K; Yoganathan, Ajit P

    2014-09-22

    Despite pressing needs, there are currently no FDA approved prosthetic valves available for use in the pediatric population. This study is performed for predictive assessment of blood damage in bileaflet mechanical heart valves (BMHVs) with pediatric sizing and flow conditions. A model of an adult-sized 23 mm St. Jude Medical (SJM) Regent(™) valve is selected for use in simulations, which is scaled in size for a 5-year old child and 6-month old infant. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow with thousands of suspended platelets for cases of adult, child, and infant BMHV flows. Adult BMHV flows demonstrate more disorganized small-scale flow features, but pediatric flows are associated with higher fluid shear stresses. Platelet damage in the pediatric cases is higher than in adult flow, highlighting thrombus complication dangers of pediatric BMHV flows. This does not necessarily suggest clinically important differences in thromboembolic potential. Highly damaged platelets in pediatric flows are primarily found far downstream of the valve, as there is less flow recirculation in pediatric flows. In addition, damage levels are well below expected thresholds for platelet activation. The extent of differences here documented between the pediatric and adult cases is of concern, demanding particular attention when pediatric valves are designed and manufactured. However, the differences between the pediatric and adult cases are not such that development of pediatric sized valves is untenable. This study may push for eventual approval of prosthetic valves resized for the pediatric population. Further studies will be necessary to determine the validity and potential thrombotic and clinical implications of these findings. PMID:25011622

  17. Resolving the extended atmosphere and the inner wind of Mira (o Ceti) with long ALMA baselines

    NASA Astrophysics Data System (ADS)

    Wong, K. T.; Kamiński, T.; Menten, K. M.; Wyrowski, F.

    2016-05-01

    Context. High angular resolution (sub)millimetre observations of asymptotic giant branch (AGB) stars, now possible with the Atacama Large Millimeter/submillimeter Array (ALMA), allow direct imaging of these objects' photospheres. The physical properties of the molecular material around these regions, which until now has only been studied by imaging of maser emission and spatially unresolved absorption spectroscopy, can be probed with radiative transfer modelling and compared to hydrodynamical model predictions. The prototypical Mira variable, o Cet (Mira), was observed as a Science Verification target in the 2014 ALMA Long Baseline Campaign, offering the first opportunity to study these physical conditions in detail. Aims: With the longest baseline of 15 km, ALMA produces clearly resolved images of the continuum and molecular line emission/absorption at an angular resolution of ~30 mas at 220 GHz. Models are constructed for Mira's extended atmosphere to investigate the physics and molecular abundances therein. Methods: We imaged the data of 28SiO ν= 0, 2J = 5-4 and H2O v2 = 1JKa,Kc = 55,0-64,3 transitions and extracted spectra from various lines of sight towards Mira's extended atmosphere. In the course of imaging the emission/absorption, we encountered ambiguities in the resulting images and spectra that appear to be related to the performance of the CLEAN algorithm when applied to a combination of extended emission, and compact emission and absorption. We addressed these issues by a series of tests and simulations. We derived the gas density, kinetic temperature, molecular abundance, and outflow/infall velocities in Mira's extended atmosphere by modelling the SiO and H2O lines. Results: We resolve Mira's millimetre continuum emission and our data are consistent with a radio photosphere with a brightness temperature of 2611 ± 51 K. In agreement with recent results obtained with the Very Large Array, we do not confirm the existence of a compact region (<5 mas) of

  18. 5. NORTH SIDE AND WEST REAR. Edwards Air Force ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. NORTH SIDE AND WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  19. 6. OUTER BLAST DOOR, WEST REAR. Edwards Air Force ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. OUTER BLAST DOOR, WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  20. 3. SOUTH SIDE. Edwards Air Force Base, South Base ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SOUTH SIDE. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  1. 7. DETAIL SHOWING BLAST SHIELDED WINDOWS, WEST SIDE. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL SHOWING BLAST SHIELDED WINDOWS, WEST SIDE. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  2. 5Q4: Chris Edwards - Child Presence Sensor

    NASA Video Gallery

    Five Questions For (5Q4) Chris Edwards, NASA engineer who was the team lead of a group that invented a child presence sensor designed to alert parents if they've inadvertently left their child in h...

  3. 14. Photocopy of Illustration from Buffet, Edward P., 'Some Long ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photocopy of Illustration from Buffet, Edward P., 'Some Long Island Windmills,' American Machinist, 17 October 1918, p. 728 STONE CRANE AT THE SHELTER ISLAND WINDMILL - Shelter Island Windmill, Manwaring Road, Shelter Island, Suffolk County, NY

  4. 4. DETAIL SHOWING FLAME DEFLECTOR. Looking southeast. Edwards Air ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL SHOWING FLAME DEFLECTOR. Looking southeast. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  5. 20. Historic American Buildings Survey Edward M. Rosenfeld, Photographer. April ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Historic American Buildings Survey Edward M. Rosenfeld, Photographer. April 20, 1934 GALLERY AND ENTRANCE FROM SOUTH PORCH - Holy Trinity Church, Seventh & Church Street, Wilmington, New Castle County, DE

  6. CONTROL BUILDING, WEST FRONT SHOWING ENTRANCE Edwards Air Force ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTROL BUILDING, WEST FRONT SHOWING ENTRANCE - Edwards Air Force Base, X-15 Engine Test Complex, Firing Control Building, Rogers Dry Lake, east of runway between North Base & South Base, Boron, Kern County, CA

  7. DETAIL, CONTROL BOOTH, RP1 TANK FARM Edwards Air Force ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL, CONTROL BOOTH, RP1 TANK FARM - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Combined Fuel Storage Tank Farm, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  8. 6. BUILDING 8768, NORTHWEST SIDE AND SOUTHWEST FRONT. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. BUILDING 8768, NORTHWEST SIDE AND SOUTHWEST FRONT. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Observation Bunkers for Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  9. 4. BUILDING 8767, INTERIOR. Looking west. Edwards Air Force ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. BUILDING 8767, INTERIOR. Looking west. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Observation Bunkers for Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  10. 2. BUILDING 8767, SOUTH FRONT AND EAST SIDE. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. BUILDING 8767, SOUTH FRONT AND EAST SIDE. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Observation Bunkers for Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  11. 8. SOUTH REAR, SUPERSTRUCTURE. Looking north from deck. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. SOUTH REAR, SUPERSTRUCTURE. Looking north from deck. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  12. 8. BUILDING 8769, WEST FRONT AND SOUTH SIDE. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. BUILDING 8769, WEST FRONT AND SOUTH SIDE. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Observation Bunkers for Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  13. 5. EAST SIDE, TEST STAND AND ITS SUPERSTRUCTURE. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. EAST SIDE, TEST STAND AND ITS SUPERSTRUCTURE. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  14. 7. MOTION PICTURE CAMERA STAND AT BUILDING 8768. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. MOTION PICTURE CAMERA STAND AT BUILDING 8768. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Observation Bunkers for Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  15. Edward Mills Purcell, August 30, 1912-March 7, 1997

    NASA Astrophysics Data System (ADS)

    Rigden, John S.

    2011-03-01

    I discuss the life, education, personality, and contributions of Edward Mills Purcell (1912-1997) to physics, radio astronomy, astrophysics, biological physics, physics teaching and education, and to the nation.

  16. SOUTHEAST AND NORTHEAST SIDES. Looking west Edwards Air Force ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SOUTHEAST AND NORTHEAST SIDES. Looking west - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Fuel & Water Tank, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  17. 3. Photocopy of lithograph by Edward A. Wilson, owned by ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Photocopy of lithograph by Edward A. Wilson, owned by Mrs. Arthur Williams, owner of the house in 1960. JOSHUA DYER HOUSE FROM THE REAR - Joshua Dyer House, North Pamet Road, Truro, Barnstable County, MA

  18. Episodic karstification, Edwards Plateau, central Texas

    SciTech Connect

    Kastning, E.H.

    1985-01-01

    The Edwards Plateau and Llano Basin of central Texas form one of the largest contiguous regions of karst in North America (>80,000 km/sup 2/). Solutional phenomena show that several major episodes of karstification are documentable from late Cambrian to Holocene. Relict landforms representing intervals of solutional activity correlate well with the accepted geomorphic chronology for central Texas. Secondary porosity are vertically controlled by lithology, topographic incision of streams, position of the potentiometric surface, and attitude of bedding. Areally, development of karst is strongly influenced by the extent, density, and orientation of fractures and by hydrodynamic characteristics such as points of recharge and discharge, degree of integration of groundwater flow paths, and hydraulic gradients. Early episodes of karstification correspond to intervals of subaerial exposure of carbonate rocks during marine regression or following regional uplift. Paleokarst is prevalent in the Paleozoic and Mesozoic sequences. Infilled dolines and solution-collapse breccias have been exhumed by extensive regional denudation during the Cenozoic Era. Subaerial conditions during the middle Cretaceous account for infilled solutional cavities within lower Cretaceous carbonate beds. The most extensive karstification began with regional uplift in the early Miocene. Enhanced relief along the Balcones escarpment promoted incision of streams, lowering of water tables, steepened hydraulic gradients, and increases in discharge. Caves at various-elevations attest to sequential dissection of the plateau during the late Quaternary.

  19. Craniofacial abnormalities among patients with Edwards Syndrome

    PubMed Central

    Rosa, Rafael Fabiano M.; Rosa, Rosana Cardoso M.; Lorenzen, Marina Boff; Zen, Paulo Ricardo G.; Graziadio, Carla; Paskulin, Giorgio Adriano

    2013-01-01

    OBJECTIVE To determine the frequency and types of craniofacial abnormalities observed in patients with trisomy 18 or Edwards syndrome (ES). METHODS This descriptive and retrospective study of a case series included all patients diagnosed with ES in a Clinical Genetics Service of a reference hospital in Southern Brazil from 1975 to 2008. The results of the karyotypic analysis, along with clinical data, were collected from medical records. RESULTS: The sample consisted of 50 patients, of which 66% were female. The median age at first evaluation was 14 days. Regarding the karyotypes, full trisomy of chromosome 18 was the main alteration (90%). Mosaicism was observed in 10%. The main craniofacial abnormalities were: microretrognathia (76%), abnormalities of the ear helix/dysplastic ears (70%), prominent occiput (52%), posteriorly rotated (46%) and low set ears (44%), and short palpebral fissures/blepharophimosis (46%). Other uncommon - but relevant - abnormalities included: microtia (18%), orofacial clefts (12%), preauricular tags (10%), facial palsy (4%), encephalocele (4%), absence of external auditory canal (2%) and asymmetric face (2%). One patient had an initial suspicion of oculo-auriculo-vertebral spectrum (OAVS) or Goldenhar syndrome. CONCLUSIONS: Despite the literature description of a characteristic clinical presentation for ES, craniofacial alterations may be variable among these patients. The OAVS findings in this sample are noteworthy. The association of ES with OAVS has been reported once in the literature. PMID:24142310

  20. MD-11 PCA - First Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A transport aircraft lands for the first time under engine power only, as this McDonnell Douglas MD-11 touches down at 11:38 a.m., Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

  1. MD-11 PCA - First Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A transport aircraft lands for the first time under engine power only, as this McDonnell Douglas MD-11 touches down at 11:38 a.m., Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

  2. New Measurements of the Radio Photosphere of Mira Based on Data from the JVLA and ALMA

    NASA Astrophysics Data System (ADS)

    Matthews, L. D.; Reid, M. J.; Menten, K. M.

    2015-07-01

    We present new measurements of the millimeter wavelength continuum emission from the long period variable Mira (o Ceti) at frequencies of 46, 96, and 229 GHz (λ ≈ 7, 3, and 1 mm) based on observations obtained with the Jansky Very Large Array (JVLA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The measured millimeter flux densities are consistent with a radio photosphere model derived from previous observations, where flux density {S}ν \\propto {ν }1.86. The stellar disk is resolved, and the measurements indicate a decrease in the size of the radio photosphere at higher frequencies, as expected if the opacity decreases at shorter wavelengths. The shape of the radio photosphere is found to be slightly elongated, with a flattening of ∼10%–20%. The data also reveal evidence for brightness non-uniformities on the surface of Mira at radio wavelengths. Mira’s hot companion, Mira B was detected at all three observed wavelengths, and we measure a radius for its radio-emitting surface of ≈ 2.0× {10}13 cm. The data presented here highlight the power of the JVLA and ALMA for the study of the atmospheres of evolved stars.

  3. MIRA: review of inputs from updated results of the phobos mission

    NASA Astrophysics Data System (ADS)

    Moroz, V. I.; Korablev, O. I.; Rodin, A. V.; Titov, D. V.

    1999-01-01

    The future Mars International Reference Atmosphere (MIRA) is intended to replace the present COSPAR Mars Reference Model compiled in 1979 on the basis of Mariner 9 and Viking 1,2 missions results. At the moment, several sources of the post-Viking data potentially useful for MIRA are available. Among them is a data set obtained during Phobos mission in 1989. The interpretation of these data has undergone thorough refinement, so final recommendations for MIRA can be made. The principal points are: 1) vertical profile of water vapor with a ``knee'' at the height about 25 km retrieved in the spring equinox season near equator; 2) variations of water vapor column density including peculiarities on the slopes of high mountains; 3) vertical profiles of ozone; 4) new estimates of CO abundance; 5) surface pressure/height mapping (CO2 altimetry) in selected regions; 6) optical depths of aerosols; 7) vertical profiles of aerosol between surface and 40 km; 8) properties of high altitude ice layers and clouds above mountains; 9) microphysical properties of aerosol particles (size, composition, and number density estimates). The data have been obtained by means of instruments AUGUSTE (UV and NIR spectrometers for limb sounding of the atmosphere using solar occultations), ISM (NIR scanning spectrometer), TERMOSKAN (thermal IR scanning radiometer), KRFM (near-UV and visible multi-band photometer). The observations were performed in equatorial regions during northern spring (solar aerocentric longitudes 8° < Ls < 18°).

  4. The Optical Gravitational Lensing Experiment. Miras and Semiregular Variables in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Soszynski, I.; Udalski, A.; Kubiak, M.; Szymanski, M. K.; Pietrzynski, G.; Zebrun, K.; Szewczyk, O.; Wyrzykowski, L.; Ulaczyk, K.

    2005-12-01

    We use the OGLE-II and OGLE-III data in conjunction with the 2MASS near-infrared (NIR) photometry to identify and study Miras and Semiregular Variables (SRVs) in the Large Magellanic Cloud. We found in total 3221 variables of both types, populating two of the series of NIR period--luminosity (PL) sequences. The majority of these objects are double periodic pulsators, with periods belonging to both PL ridges. We indicate that in the period -- Wesenheit index plane the oxygen-rich and carbon-rich AGB stars from the NIR PL sequences C, C' and D split into well separated ridges. Thus, we discover an effective method of distinguishing between O-rich and C-rich Miras, SRVs and stars with Long Secondary Periods using their V and I-band photometry. We present an empirical method of estimating the mean K_s magnitudes of the Long Period Variables using single-epoch K_s measurements and complete light curves in the I-band. We utilize these corrected magnitudes to show that the O-rich and C-rich Miras and SRVs follow somewhat different K_s-band PL relations.

  5. Resolving asymmetries along the pulsation cycle of the Mira star X Hydrae

    NASA Astrophysics Data System (ADS)

    Haubois, X.; Wittkowski, M.; Perrin, G.; Kervella, P.; Mérand, A.; Thiébaut, E.; Ridgway, S. T.; Ireland, M.; Scholz, M.

    2015-10-01

    Context. The mass-loss process in Mira stars probably occurs in an asymmetric way where dust can form in inhomogeneous circumstellar molecular clumps. Following asymmetries along the pulsation cycle can give us clues about these mass-loss processes. Aims: We imaged the Mira star X Hya and its environnement at different epochs to follow the evolution of the morphology in the continuum and in the molecular bands. Methods: We observed X Hya with AMBER in J-H-K at low resolution at two epochs. We modelled squared visibilities with geometrical and physical models. We also present imaging reconstruction results obtained with MiRA and based on the physical a priori images. Results: We report on the angular scale change of X Hya between the two epochs. 1D CODEX profiles allowed us to understand and model the spectral variation of squared visibilities and constrain the stellar parameters. Reconstructed model-dependent images enabled us to reproduce closure phase signals and the azimuthal dependence of squared visibilities. They show evidence for material inhomogeneities located in the immediate environment of the star. Based on observations obtained with the ESO VLTI/ATs telescopes under the program ID 084.D-0326. Figures 7-12 are available in electronic form at http://www.aanda.org

  6. Infrared variability of the symbiotic Mira V407 Cygni and the structure of its dust envelope

    NASA Astrophysics Data System (ADS)

    Yudin, B. F.

    1999-03-01

    We perform an in-depth analysis of the infrared variability of the symbiotic Mira V407 Cyg resulting both from its pulsations and from a secular trend in its mean brightness. The two effects are shown to be similar in nature and are attributable to a change in the bolometric luminosity of the Mira in combination with a change in its temperature and/or in the optical depth of its dust envelope. In the last fourteen years, the mean bolometric luminosity has risen by ~30%, which must have been reflected in an increase of the pulsation period by delta P/P >= 0.1. The optical depth tau(J) of the dust envelope decreased by ~0.06, or the temperature of the Mira rose by ~100 K. Both of these effects result in approximately the same displacement of the star in the (J-L, K) diagram, which is most suitable for estimating variations in the parameters (L, T, tau). The changes in the shape of the energy distribution observed during pulsations of the Mira can be explained in terms of the dust-envelope model in which a new dust layer condenses during the pulsation minimum at a distance of ~3.5 R*. It consists of a mixture of silicate and graphite grains with a total mass of ~7 x 10^-9 M_solar. At this time, more than half of the optical depth of the entire dust envelope is concentrated in this layer, which changes by a factor of ~2 in half the pulsation period (~745d). Near the pulsation maximum, tau(J) ~0.25 and the inner radius of the dust envelope is R_in ~ 5 R*. Over the past ~10^4 years, the Mira has lost its mass at an approximately constant rate of ~5 x 10^-7 M_solar yr^-1 for M_gas/M_dust ~200. The dust envelope may be composed either of small (~0.01 micron) or large (~0.1 micron) grains. In the latter case, it should be kept in mind that these grains rather than medium-sized (~0.05 micron) ones determine its optical depth. We analyze the dust-envelope models in detail in terms of their possible observational verification.

  7. STS-66 Edwards Landing with Drag Chute

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Atlantis lands with its drag chute deployed on runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) 14 November 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to

  8. X-31 in Flight over Edwards AFB

    NASA Technical Reports Server (NTRS)

    1994-01-01

    One of two X-31 Enhanced Fighter Maneuverability Demonstrator aircraft, flown by an international test organization at NASA's Dryden Flight Research Center, Edwards, California, turns tightly over the desert floor on a research flight. The aircraft obtained data that may apply to the design and development of highly-maneuverable aircraft of the future. The X-31 had a three-axis thrust-vectoring system, coupled with advanced flight controls, to allow it to maneuver tightly at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight

  9. Are anticoagulant independent mechanical valves within reach—fast prototype fabrication and in vitro testing of innovative bi-leaflet valve models

    PubMed Central

    Siegel, Rolland

    2015-01-01

    Background Exploration for causes of prosthetic valve thrombogenicity has frequently focused on forward or post-closure flow detail. In prior laboratory studies, we uncovered high amplitude flow velocities of short duration close to valve closure implying potential for substantial shear stress with subsequent initiation of blood coagulation pathways. This may be relevant to widely accepted clinical disparity between mechanical and tissue valves vis-à-vis thrombogenicity. With a series of prototype bi-leaflet mechanical valves, we attempt reduction of closure related velocities with the objective of identifying a prototype valve with thrombogenic potential similar to our tissue valve control. This iterative design approach may find application in preclinical assessment of valves for anticoagulation independence. Methods Tested valves included: prototype mechanical bi-leaflet BVs (n=56), controls (n=2) and patented early prototype mechanicals (n=2) from other investigators. Pulsatile and quasi-steady flow systems were used for testing. Projected dynamic valve area (PDVA) was measured using previously described novel technology. Flow velocity over the open and closing periods was determined by volumetric flow rate/PDVA. For the closed valve interval, use was made of data obtained from quasi-steady back pressure/flow tests. Performance was ranked by a proposed thrombogenicity potential index (TPI) relative to tissue and mechanical control valves. Results Optimization of the prototype valve designs lead to a 3-D printed model (BV3D). For the mitral/aortic site, BV3D has lower TPI (1.10/1.47) relative to the control mechanical valve (3.44/3.93) and similar to the control tissue valve (ideal TPI ≤1.0). Conclusions Using unique technology, rapid prototyping and thrombogenicity ranking, optimization of experimental valves for reduced thrombogenic potential was expedited and simplified. Innovative mechanical valve configurations were identified that merit consideration

  10. STS-29 Landing Approach at Edwards

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The STS-29 Space Shuttle Discovery mission approaches for a landing at NASA's then Ames-Dryden Flight Research Facility, Edwards AFB, California, early Saturday morning, 18 March 1989. Touchdown was at 6:35:49 a.m. PST and wheel stop was at 6:36:40 a.m. on runway 22. Controllers chose the concrete runway for the landing in order to make tests of braking and nosewheel steering. The STS-29 mission was very successful, completing the launch a Tracking and Data Relay communications satellite, as well as a range of scientific experiments. Discovery's five man crew was led by Commander Michael L. Coats, and included pilot John E. Blaha and mission specialists James P. Bagian, Robert C. Springer, and James F. Buchli. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload

  11. STS-37 Shuttle Crew after Edwards landing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The crew of the Space Shuttle Atlantis gives the 'all's well' thumb's-up sign after leaving the 100-ton orbiter following their landing at 6:55 a.m. (PDT), 11 April 1991, at NASA's Ames Dryden Flight Research Facility (later redesignated Dryden Flight Research Center), Edwards, California, to conclude mission STS-37. They are, from left, Kenneth D. Cameron, pilot; Steven R. Nagel, mission commander; and mission specialists Linda M. Godwin, Jerry L. Ross, and Jay Apt. During the mission,which began with launch April 5 at Kennedy Space Center, Florida, the crew deployed the Gamma Ray Observatory. Ross and Jay also carried out two spacewalks, one to deploy an antenna on the Gamma Ray Observatory and the other to test equipment and mobility techniques for the construction of the future Space Station. The planned five-day mission was extended one day because of high winds at Edwards. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space

  12. STS-66 Edwards Landing with Drag Chute

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Atlantis lands with its drag chute deployed on runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) 14 November 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to

  13. STS-67 Endeavour Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The space shuttle Endeavour slips to a smooth landing on runway 22 at Edwards, California, to complete the highly successful record-setting STS-67 mission. The landing was at 1:46 p.m. (PST) 18 March 1995, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather. Launched into space at 10:38 a.m. (PST) 1 March 1995, the Endeavour crew conducted NASA's longest shuttle flight to date and carried unique ultraviolet telescopes (ASTRO-2) which captured views of the universe impossible to obtain from the ground. Mission Commander was Steve Oswald making his third flight and the Pilot was Bill Gregory on his first mission. Mission Specialist 1 was John Grunsfeld making his first flight and Specialist 2 was Wendy Lawrence on her first flight. Tamara Jernigan served as Specialist 3 on her third flight and the two payload specialists were Samuel Durrance and Ronald Parise, both on their second flight. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads

  14. STS-29 Landing Approach at Edwards

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The STS-29 Space Shuttle Discovery mission approaches for a landing at NASA's then Ames-Dryden Flight Research Facility, Edwards AFB, California, early Saturday morning, 18 March 1989. Touchdown was at 6:35:49 a.m. PST and wheel stop was at 6:36:40 a.m. on runway 22. Controllers chose the concrete runway for the landing in order to make tests of braking and nosewheel steering. The STS-29 mission was very successful, completing the launch a Tracking and Data Relay communications satellite, as well as a range of scientific experiments. Discovery's five man crew was led by Commander Michael L. Coats, and included pilot John E. Blaha and mission specialists James P. Bagian, Robert C. Springer, and James F. Buchli. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload

  15. Dependence of SMOS/MIRAS brightness temperatures on wind speed: sea surface effect and latitudinal biases

    NASA Astrophysics Data System (ADS)

    Yin, Xiaobin; Boutin, Jacqueline; Martin, Nicolas; Spurgeon, Paul

    2013-04-01

    SMOS (Soil Moisture and Ocean Salinity) has been successfully launched in November 2009 and its only payload, Microwave Imaging Radiometer using Aperture Synthesis (MIRAS) instrument, is the first interferometric radiometer at L band (1.4GHz) in orbit. MIRAS employs aperture synthesis in 2D with a Y-shaped antenna structure to create an image of emissions from the Earth surface at L-band over a range of incidence angles (0° to 65°) with a spatial resolution of 35 to 110 km. More than two years after launch the level 1C (L1C) brightness temperatures (TBs) reprocessed with the up-to-date ESA level 1 processing version (the Level 1 processor V5.04 and V5.05), have been released. It has been shown during the commissioning phase that the receivers onboard of MIRAS are affected by a short-term drift during each orbit, and a seasonal variation due to the thermal drifts of the antenna patch. Although a new antenna model is incorporated in the ESA L1 V5 processing to account for these variations, latitudinal and seasonal drifts in L1C TBs are still observed. In this presentation, we first investigate the impact of the TB drifts on the sea surface emissivity roughness model we derived in Yin et al. (TGRS 2012) from multi-latitude level 1 V3.17 TBs. We then study dependencies of TBs at multi-incidence angles with wind speed separately for various latitudinal bands and different seasons in order to separate artificial effects of TB drifts from sea surface effects. We then propose a new roughness/foam forward model. We estimate the quality of SMOS retrieved SSS by comparing it with ARGO measurements, and discuss SSS quality given the imprecision of the forward model and of the wind speed used as prior value in the level 2 ocean salinity processor.

  16. Mathematical Existence Results for the Doi-Edwards Polymer Model

    NASA Astrophysics Data System (ADS)

    Chupin, Laurent

    2016-07-01

    In this paper, we present some mathematical results on the Doi-Edwards model describing the dynamics of flexible polymers in melts and concentrated solutions. This model, developed in the late 1970s, has been used and extensively tested in modeling and simulation of polymer flows. From a mathematical point of view, the Doi-Edwards model consists in a strong coupling between the Navier-Stokes equations and a highly nonlinear constitutive law. The aim of this article is to provide a rigorous proof of the well-posedness of the Doi-Edwards model, namely that it has a unique regular solution. We also prove, which is generally much more difficult for flows of viscoelastic type, that the solution is global in time in the two dimensional case, without any restriction on the smallness of the data.

  17. Untersuchung der Mira-Sterne RT Boo, TV Peg und VX Aur

    NASA Astrophysics Data System (ADS)

    Raetz, Kerstin; Berthold, Thomas

    2015-02-01

    The light-change of the Mira stars RT Boo, TV Peg and VX Aur was analyzed on three ways for a long time. In the first period I estimated the brightness of the variables on sky monitoring photo plates (red spectral range) from Sonneberg Observatory with Argelander¥s Method, in the last years I measured scanned photo plates with a photometry program and in addition I used visual observations from A.A.V.S.O. for the analysis. The behavior of the periods of the tree stars from 1965 to 2013 is described here.

  18. Oxygen-rich Mira variables: Near-infrared luminosity calibrations. Populations and period-luminosity relations

    NASA Technical Reports Server (NTRS)

    Alvarez, R.; Mennessier, M.-O.; Barthes, D.; Luri, X.; Mattei, J. A.

    1997-01-01

    Hipparcos astrometric and kinematical data of oxygen-rich Mira variables are used to calibrate absolute near-infrared magnitudes and kinematic parameters. Three distinct classes of stars with different kinematics and scale heights were identified. The two most significant groups present characteristics close to those usually assigned to extended/thick disk-halo populations and old disk populations, respectively, and thus they may differ by their metallicity abundance. Two parallel period-luminosity relations are found, one for each population. The shift between these relations is interpreted as the consequence of the effects of metallicity abundance on the luminosity.

  19. Time Variation Observations of Mid-Infrared Spectra of Mira Variables in NEP and LMC

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Miyata, Takashi; Okada, Yoko; Sakon, Itsuki; Tanabe, Toshihiko; Yamamura, Issei

    2004-09-01

    We propose to derive the optical properties of their circumstellar dust grains and dust formation process based on variability observations of mid-infrared (MIR) spectra of oxygen-rich Mira variables with the IRS SL and LL modules. Mass-loss of stars in the asymptotic-giant branch is an important process for the evolution of matter in the Galaxy. However, there are still large uncertainties in the optical properties of silicate grains and the dust formation process in their circumstellar envelopes. Based on variability observations with the ISO of MIR spectra of a Mira variable we were able to derive the dust optical properties and the inner dust shell temperature independently, which have clearly demonstrated the effectiveness of variability observations of MIR spectra. However, they also indicate that the variability and dust properties in Mira variables have diversity and it is quite important to apply the same method to other targets and extend the investigation. We selected 3 target stars in the north ecliptic polar (NEP) region and 2 in the Large Magellanic Cloud (LMC). Both regions are located in the constant viewing zones and all the target stars can be observed for more than 11 months in a year. We propose to make observations in the intervals of 1/5 of the period over a variability cycle. Three targets in the NEP have periods less than 300 days and they can be observed over a variability cycle in Cycle-1. Two target stars in the LMC have periods longer than 500 days and we request multi-cycle observations to cover a variability cycle of the LMC targets. We allow +/-15 days for the NEP stars and +/-30 days for the LMC stars for each observation epoch and thus the timing constraint is not severe. The IRS on board the SST provides a unique opportunity to carry out this study, which enables us to investigate the diversity of properties and formation process of silicate grains in Mira variables and extend our understanding to those in the nearby galaxy LMC.

  20. Search for surface magnetic fields in Mira stars. First detection in χ Cygni

    NASA Astrophysics Data System (ADS)

    Lèbre, A.; Aurière, M.; Fabas, N.; Gillet, D.; Herpin, F.; Konstantinova-Antova, R.; Petit, P.

    2014-01-01

    Context. So far, surface magnetic fields have never been detected on Mira stars. Only recently have the spectropolarimetric capabilities of measuring it via the Zeeman effect become available to us. Then, to complete the knowledge of the magnetic field and of its influence during the transition from asymptotic giant branch to planetary nebulae stages, we have undertaken a search for magnetic fields on the surface of Mira stars. Aims: Our main goal is to constrain - at this stage of stellar evolution - the surface magnetic field (presence and strength) and to define the magnetic field strength dependence along the radial distance to the star, above the photosphere and across the circumstellar envelope of cool and evolved stars. Methods: We used spectropolarimetric observations (Stokes V spectra probing circular polarization), collected with the Narval instrument at TBL, in order to detect - with the least squares deconvolution (LSD) method - a Zeeman signature in the visible part of the spectrum. Results: We present the first spectropolarimetric observations of the S-type Mira star χ Cyg, performed around its maximum light. We detected a polarimetric signal in the Stokes V spectra and established its Zeeman origin. We claim that it is likely to be related to a weak magnetic field present at the photospheric level and in the lower part of the stellar atmosphere. We estimated the strength of its longitudinal component to about 2-3 gauss. This result favors a 1/r law for the variation in the magnetic field strength across the circumstellar envelope of χ Cyg. This is the first detection of a weak magnetic field on the stellar surface of a Mira star, and we discuss its origin in the framework of shock waves periodically propagating throughout the atmosphere of these radially pulsating stars. Conclusions: At the date of our observations of χ Cyg, the shock wave reaches its maximum intensity, and it is likely that the shock amplifies a weak stellar magnetic field during

  1. A high-speed bipolar outflow from the archetypical pulsating star Mira A

    NASA Astrophysics Data System (ADS)

    Meaburn, J.; López, J. A.; Boumis, P.; Lloyd, M.; Redman, M. P.

    2009-06-01

    Optical images and high-dispersion spectra have been obtained of the ejected material surrounding the pulsating AGB star Mira A. The two streams of knots on either side of the star, found in far-ultraviolet (FUV) GALEX images, have now been imaged clearly in the light of Hα. Spatially resolved profiles of the same line reveal that the bulk of these knots form a bipolar outflow with radial velocity extremes of ±150 km s-1 with respect to the central star. The south stream is approaching and the north stream receding from the observer. A displacement away from Mira A between the position of one of the south-stream knots in the new Hα image and its position in the previous Palomar Observatory Sky Survey (POSS I) red plate was noted. If interpreted as a consequence of expansion proper motions, the bipolar outflow is tilted at 69° ± 15° to the plane of the sky, has an outflow velocity of 160 ± 10 km s-1 and is ≈1000 y old.

  2. High-angular-resolution stellar imaging with occultations from the Cassini spacecraft - III. Mira

    NASA Astrophysics Data System (ADS)

    Stewart, Paul N.; Tuthill, Peter G.; Nicholson, Philip D.; Hedman, Matthew M.

    2016-04-01

    We present an analysis of spectral and spatial data of Mira obtained by the Cassini spacecraft, which not only observed the star's spectra over a broad range of near-infrared wavelengths, but was also able to obtain high-resolution spatial information by watching the star pass behind Saturn's rings. The observed spectral range of 1-5 microns reveals the stellar atmosphere in the crucial water-bands which are unavailable to terrestrial observers, and the simultaneous spatial sampling allows the origin of spectral features to be located in the stellar environment. Models are fitted to the data, revealing the spectral and spatial structure of molecular layers surrounding the star. High-resolution imagery is recovered revealing the layered and asymmetric nature of the stellar atmosphere. The observational data set is also used to confront the state-of-the-art cool opacity-sampling dynamic extended atmosphere models of Mira variables through a detailed spectral and spatial comparison, revealing in general a good agreement with some specific departures corresponding to particular spectral features.

  3. Spectroscopy and Photometry of the Mira Variables R Leo, R CVn, and V CVn

    NASA Astrophysics Data System (ADS)

    Lingerfelt, E.; Clark, C. J.; Castelaz, M. W.

    1997-12-01

    Spectra of Mira stars from about 6200 Angstroms to 8800 Angstroms were taken in a search for anticorrelation between the Hα emission feature and the CaII infrared triplet. This anticorrelation is indicative of the flourescence of Hepsilon photons by CaII, which may explain the near absence of Hepsilon when the other Balmer emission lines are present (Castelaz & Luttermoser 1997, AJ, 114, 1584). The spectra also provides a measure of effective temperature. We will present spectra for R Leo, R Cvn, and V CVn taken in February, March, and May of 1997 using a low resolution spectrograph onboard the Southeastern Association for Research in Astronomy 0.9-meter telescope at Kitt Peak, Arizona. We will also present an initial set of differential BVRI photometry of the Mira stars taken nearly simultaneously with the spectra. The authors gratefully acknowledge support from NSF grant AST-9500756. Eric Lingerfelt and Clayton Clark are undergraduates at ETSU who greatly appreciate support from an NSF REU Supplement grant.

  4. Annual parallax and a dimming event of a Mira variable star, FV Bootis

    NASA Astrophysics Data System (ADS)

    Kamezaki, Tatsuya; Nakagawa, Akiharu; Omodaka, Toshihiro; Inoue, Kan-ichiro; Chibueze, James O.; Nagayama, Takumi; Ueno, Yuji; Matsunaga, Noriyuki

    2016-08-01

    We present the first measurement of the trigonometric parallax of water masers associated with a Mira star, FV Bootis (FV Boo) using VLBI Exploration of Radio Astrometry (VERA). Based on our multi-epoch VERA observations, we derived the parallax to be 0.97 ± 0.06 mas, which corresponds to a distance of 1.03^{+0.07}_{-0.06} kpc. The water masers around FV Boo were spatially distributed over an area of 41 au × 41 au, and their internal motions indicate the presence of an outflow. Using the Kagoshima University 1 m optical/infrared telescope, we determined the period to be 305.6 d and the mean apparent magnitude to be +2.91 mag in the K'-band. On the period-luminosity plane, the obtained period and K'-band magnitude puts FV Boo slightly below the sequence of Miras, possibly due to circumstellar reddening. Combining our photometric data with COBE and 2MASS datasets spanning over 20 years, we found in the near infrared that FV Boo was significantly fainter in 2005 compared with preceding and later phases. Its color, however, did not show a large variation through this change. We infer that the dimming could be caused by an eclipse due to a cloud in a binary system.

  5. Mary Edwards Walker: the soul ahead of her time.

    PubMed

    Rehman, Atiq; Rahman, Naba G; Harris, Sharon M; Cheema, Faisal H

    2015-02-01

    Mary Edwards Walker was a gallant woman who stood for women's rights, embodied the true American spirit, and served the Union Army in the Civil War as a surgeon. She later became the first and only woman in United States history to be awarded the Congressional Medal of Honor. PMID:25535874

  6. Quality in Higher Education: The Contribution of Edward Demings Principles

    ERIC Educational Resources Information Center

    Redmond, Richard; Curtis, Elizabeth; Noone, Tom; Keenan, Paul

    2008-01-01

    Purpose--There can be little doubt about the importance and relevance of quality for any service industry. One of the most influential contributors to service quality developments was W. Edwards Deming (1900-1993). An important component of Demings philosophy is reflected in his 14-principles for transforming a service as they indicate what…

  7. Introducing Edward L. Bernays, the "Father of Public Relations."

    ERIC Educational Resources Information Center

    Yeager, Robert J.

    1985-01-01

    Relates some of the public relations achievements and techniques of Edward L. Bernays. Sees modern public relations proceeding from an understanding of individuals, institutions and social groups, and their interrelationships. Considers the information dissemination, persuasion, and attitude integration functions of public relations. Lists…

  8. Edward Lear, Limericks, and Nonsense: A Little Nonsense. [Lesson Plan].

    ERIC Educational Resources Information Center

    2002

    British poet Edward Lear (1812-1888) is widely recognized as the father of the limerick form of poetry and is well known for his nonsense poems. In the first lesson for grades 3-5, which focuses on Lear's nonsense poem "The Owl and the Pussy Cat," students learn about nonsense poetry as well as the various poetic techniques and devices that poets…

  9. The Small Rural Schools of Prince Edward Island.

    ERIC Educational Resources Information Center

    Edmonds, E. L.

    In 1973, there were 56 one- and two-room elementary schools in Prince Edward Island (Canada). As part of a descriptive survey of these schools, now closed by consolidation, researchers visited each school in 1973 and recorded details of the buildings, facilities, and school organizations. Teachers from 47 schools and their 737 students in grades…

  10. The development of the Starr-Edwards heart valve.

    PubMed Central

    Matthews, A M

    1998-01-01

    Development of the Starr-Edwards heart valve marked a new era in the treatment of valvular heart disease. Until the development of the Starr-Edwards valve, there were no published reports of patients who had lived longer than 3 months with a prosthetic valve in the mitral position. This valve was the result of a unique partnership between a young surgeon, Dr. Albert Starr, and an experienced engineer, Mr. Lowell Edwards. Working as a team, these 2 men developed and successfully implanted the 1st Starr-Edwards valve within less than 2 years of their 1st meeting. Their key to success was their willingness and ability to make repeated modifications to their design to solve each clinical problem as it arose. Their constant focus on the clinical goal aided the rapid transformation of their design from a leaflet valve to a shielded ball valve, and finally to an unshielded ball valve suitable for implantation in a human being. Along the way, they abandoned the idea of imitating the appearance of native valves, in favor of developing valves that would be clinically successful. Their work has provided help and hope for patients who otherwise would have died from the complications of rheumatic heart disease and other valvular disorders for which valve replacement is the only treatment. Images PMID:9885105

  11. Edward Christopher Williams and His Impact on Librarianship.

    ERIC Educational Resources Information Center

    Latimer, Carlos

    Edward Christopher Williams had a major impact on librarianship, not only as the first documented African American to graduate from a library school, but also as a developer of education for librarians and as an active member of the American Library Association (ALA) and the Ohio Library Association. This study used the historical methodology…

  12. STS-67 landing at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The drag chute is fully deployed in this view of the Space Shuttle Endeavour as it completes a mission of almost 17 days duration in space on runway 22 at Edwards Air Force Base in southern California. Landing occurred at 1:46 p.m. (EST), March 18, 1995.

  13. STS-67 landing at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Space Shuttle Endeavour, after completing a mission of almost 17 days duration in space, touches down on runway 22 at Edwards Air Force Base in southern California. Landing occurred at 1:46 p.m. (EST), March 18, 1995. In this photo the nose gear is still in the air as the orbiter touches down.

  14. STS-66 landing at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The main landing gear is on the ground and the nose gear is about to touch down as the Space Shuttle Atlantis heads toward a stop at Edwards Air Force Base in southern California, ending a successful 10 day, 22 hour and 34 minute space mission. Landing occured at 7:34 a.m. (PST), November 14, 1994.

  15. STS-66 landing at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The drag chute is fully deployed as the Space Shuttle Atlantis heads toward a stop at Edwards Air Force Base in southern California, ending a successful 10 day, 22 hour and 34 minute space mission. Landing occured at 7:34 a.m. (PST), November 14, 1994.

  16. Dr. Edward de Bono's Six Thinking Hats and Numeracy

    ERIC Educational Resources Information Center

    Paterson, Anne

    2006-01-01

    In education, the term "metacognition" describes thinking about thinking. Within mathematics, the term "metacomputation" describes thinking about computational methods and tools. This article shows how Dr. Edward de Bono's Six Thinking Hats can be used to demonstrate metacognition and metacomputation in the primary classroom. The article suggests…

  17. What's Wrong with "Edward the Unready"? Our Responsibility for Readiness.

    ERIC Educational Resources Information Center

    Graue, M. Elizabeth

    1998-01-01

    Describes how Rosemary Wells's new books about "Edward Unready" explain children and readiness; explores the problems with her message, and suggests new endings that are more supportive of all children. Asserts that variability in development should not be mistaken for deficit, and recommends changing the focus from judging children to judging…

  18. Edward Teller and Nuclei:. Along the Trail to the Neutrino

    NASA Astrophysics Data System (ADS)

    Haxton, W. C.

    2010-01-01

    I discuss two of Edward Teller's contributions to nuclear physics, the introduction of the Gamow-Teller operator in β decay and the formulation of the Goldhaber-Teller model for electric dipole transitions, in the context of efforts to understand the weak interaction and the nature of the neutrino.

  19. STS-67 Endeavour Landing at Edwards

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The space shuttle Endeavour slips to a smooth landing on runway 22 at Edwards, California, to complete the highly successful record-setting STS-67 mission. The landing was at 1:46 p.m. (PST) 18 March 1995, after waiving off from the Kennedy Space Center, Florida, earlier that morning due to adverse weather. Launched into space at 10:38 a.m. (PST) 1 March 1995, the Endeavour crew conducted NASA's longest shuttle flight to date and carried unique ultraviolet telescopes (ASTRO-2) which captured views of the universe impossible to obtain from the ground. Mission Commander was Steve Oswald making his third flight and the Pilot was Bill Gregory on his first mission. Mission Specialist 1 was John Grunsfeld making his first flight and Specialist 2 was Wendy Lawrence on her first flight. Tamara Jernigan served as Specialist 3 on her third flight and the two payload specialists were Samuel Durrance and Ronald Parise, both on their second flight. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads

  20. Obituary: Harrison Edward Radford, 1927-2000

    NASA Astrophysics Data System (ADS)

    Moran, James Michael; Kirby, Kate Page; Chance, Kelly V.; Brown, Campbell

    2003-12-01

    Harrison Edward ``Harry" Radford, a noted laboratory spectroscopist and pioneer in the application of magnetic resonance techniques to spectroscopy, died on 5 May 2000, after a long battle with amyotropic lateral sclerosis (ALS). During a 37-year career at the National Bureau of Standards and the Smithsonian Astrophysical Observatory, Harry measured the frequencies of numerous molecular transitions which aided the emerging field of astrochemistry. Harry was both an excellent theoretician and a preeminently skilled experimentalist. He has several major spectroscopic achievements to his credit. He performed the first study of a short-lived molecular free radical, OH, by electron paramagnetic resonance spectroscopy, opening up a huge and important field of research. Together with colleagues he made the first observation of the rotational spectrum of CH by far infrared laser magnetic resonance spectroscopy and extended the technique to other molecules such as CH3O. Harry was born in Peterborough, New Hampshire, on 26 July 1927. He was the son of Harrison Edwin Radford, a roofer, and Dorothy (née Cole) Radford. He dropped out of high school to join the Navy in 1944 as an electronics technician's mate. After his discharge in 1946 he worked in the family construction business for four years as a roofer. In 1950 he entered the University of New Hampshire and graduated four years later, Summa Cum Laude, with a degree in physics. As a graduate student at Yale from 1954 to 1959 he wrote his PhD thesis under the supervision of V.W. Hughes on the microwave Zeeman spectra of oxygen and fluorine where he used the technique of paramagnetic resonance absorption in atomic vapors. In 1954 he married Mildred Spofford. They had three daughters, Susan (born in 1955), Amy (1957), and Sarah (1960). In 1974 he married Alfa Goldthwaithe Morrison, who survived him. From 1959 until 1969 Harry worked at the National Bureau of Standards (now the National Institute of Standards and Technology

  1. Obituary: Donald Edward Osterbrock, 1924-2007

    NASA Astrophysics Data System (ADS)

    Veilleux, Sylvain

    2007-12-01

    Donald Edward Osterbrock, one of the leading figures of post-World War II astronomy, died suddenly of a heart attack on 11 January 2007, while walking near his office at the University of California, Santa Cruz. He was 82 years old. His initials spelled D.E.O. (God in latin!), but he was known simply as Don to his many friends and colleagues. Don's long and productive career spanned five decades. His scientific work helped shape our understanding of lower main-sequence stars, the ionized interstellar medium, and active galactic nuclei. He was also a highly respected historian of astronomy who shed new light on 19th- and 20th-century astronomy. Don was born in Cincinnati, Ohio, on 13 July 1924. Both of his parents were of German descent and valued hard work, education, and science. They both completed their high-school education at night while working full-time during the day. His father eventually became a professor of electrical engineering at the University of Cincinnati. Don's plan to become an astronomer was put on hold when the Japanese attacked Pearl Harbor in 1941. After graduation from high school, Don joined the United States Army and trained as a meteorologist, taking all of the physics and mathematics courses required for a bachelor's degree in physics from the University of Chicago. He was eventually sent to islands in the Pacific Ocean but never was in harm's way. After three years of service, Don returned to Chicago to obtain his bachelor's degree in 1948, his M.S. in astronomy in 1949, and a Ph.D. in astronomy in 1952. Don's years at the University of Chicago and the University's Yerkes Observatory in Williams Bay, Wisconsin, were pivotal for his career and personal life. He came in contact with such luminaries as Otto Struve, Bengt Strömgren, Subrahmanyan Chandrasekhar, and William W. Morgan. At Yerkes, he also met and married Irene L. Hansen, a native of Williams Bay, who was employed as a member of the Yerkes staff. They had a son, William, now

  2. Mass-loss Rate by the Mira in the Symbiotic Binary V1016 Cygni from Raman Scattering

    NASA Astrophysics Data System (ADS)

    Sekeráš, M.; Skopal, A.

    2015-10-01

    The mass-loss rate from Mira variables represents a key parameter in our understanding of their evolutionary tracks. We introduce a method for determining the mass-loss rate from the Mira component in D-type symbiotic binaries via the Raman scattering of atomic hydrogen in the wind from the giant. Using our method, we investigated Raman He ii λ 1025\\to λ 6545 conversion in the spectrum of the symbiotic Mira V1016 Cyg. We determined its efficiency, η = 0.102, 0.148, and the corresponding mass-loss rate, \\dot{M}={2.0}-0.2+0.1× {10}-6, {2.7}-0.1+0.2× {10}-6 {M}⊙ {{{yr}}}-1, using our spectra from 2006 April and 2007 July, respectively. Our values of \\dot{M} that we derived from Raman scattering are comparable with those obtained independently by other methods. Applying the method to other Mira-white dwarf binary systems can provide a necessary constraint in the calculation of asymptotic giant branch (AGB) evolution.

  3. First-Ever Census of Variable Mira-Type Stars in Galaxy Outside the Local Group

    NASA Astrophysics Data System (ADS)

    2003-05-01

    First-Ever Census of Variable Mira-Type Stars in Galaxy Outsidethe Local Group Summary An international team led by ESO astronomer Marina Rejkuba [1] has discovered more than 1000 luminous red variable stars in the nearby elliptical galaxy Centaurus A (NGC 5128) . Brightness changes and periods of these stars were measured accurately and reveal that they are mostly cool long-period variable stars of the so-called "Mira-type" . The observed variability is caused by stellar pulsation. This is the first time a detailed census of variable stars has been accomplished for a galaxy outside the Local Group of Galaxies (of which the Milky Way galaxy in which we live is a member). It also opens an entirely new window towards the detailed study of stellar content and evolution of giant elliptical galaxies . These massive objects are presumed to play a major role in the gravitational assembly of galaxy clusters in the Universe (especially during the early phases). This unprecedented research project is based on near-infrared observations obtained over more than three years with the ISAAC multi-mode instrument at the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory . PR Photo 14a/03 : Colour image of the peculiar galaxy Centaurus A . PR Photo 14b/03 : Location of the fields in Centaurus A, now studied. PR Photo 14c/03 : "Field 1" in Centaurus A (visual light; FORS1). PR Photo 14d/03 : "Field 2" in Centaurus A (visual light; FORS1). PR Photo 14e/03 : "Field 1" in Centaurus A (near-infrared; ISAAC). PR Photo 14f/03 : "Field 2" in Centaurus A (near-infrared; ISAAC). PR Photo 14g/03 : Light variation of six variable stars in Centaurus A PR Photo 14h/03 : Light variation of stars in Centaurus A (Animated GIF) PR Photo 14i/03 : Light curves of four variable stars in Centaurus A. Mira-type variable stars Among the stars that are visible in the sky to the unaided eye, roughly one out of three hundred (0.3%) displays brightness variations and is referred to by astronomers as a

  4. Shock-induced polarized hydrogen emission lines in the Mira star o Ceti

    NASA Astrophysics Data System (ADS)

    Fabas, N.; Lèbre, A.; Gillet, D.

    2011-11-01

    Context. In the spectra of variable pulsating stars, especially Mira stars, the detection of intense hydrogen emission lines has been explained by the presence of a radiative and hypersonic shock wave, periodically propagating throughout the stellar atmosphere. Previous observation of the Mira star o Ceti around one of its brightest maximum light led to the detection of a strong level of linear polarization associated to Balmer emissions, although the origin of this phenomenon is not fully explained yet. Aims: With the help of spectropolarimetry, we propose to investigate the nature of shock waves propagating throughout the stellar atmosphere and present, for o Ceti (the prototype of Mira stars), a full observational study of hydrogen emission lines formed in the radiative region of such a shock. Methods: Using the instrument NARVAL mounted on the Télescope Bernard Lyot (TBL) in Pic du Midi Observatory (France), we performed a spectropolarimetric monitoring of o Ceti during three consecutive pulsation cycles. For this survey, the four Stokes parameters (I for intensity, Q and U for linear polarization, and V for circular polarization) were systematically collected, with a particular emphasis on the maxima of luminosity, i.e. when a radiative shock wave is supposed to emerge from the photosphere and starts to propagate outward. Results: On hydrogen Balmer lines, over a large part of the luminosity cycle, we report clear detection of polarimetric structures in Q and U Stokes spectra (and also in V Stokes spectra but to a lesser extent). We report a temporal evolution of these spectropolarimetric signatures, which appear strongly correlated to the presence of an intense shock wave responsible for the hydrogen emission lines. We establish that the hydrogen lines are polarized by a physical process inherent to the mechanism responsible for the emission line formation: the shock wave itself. Two mechanisms are thus considered: a global one that implies a polarization

  5. Obituary: Donald Edward Osterbrock, 1924-2007

    NASA Astrophysics Data System (ADS)

    Veilleux, Sylvain

    2007-12-01

    Donald Edward Osterbrock, one of the leading figures of post-World War II astronomy, died suddenly of a heart attack on 11 January 2007, while walking near his office at the University of California, Santa Cruz. He was 82 years old. His initials spelled D.E.O. (God in latin!), but he was known simply as Don to his many friends and colleagues. Don's long and productive career spanned five decades. His scientific work helped shape our understanding of lower main-sequence stars, the ionized interstellar medium, and active galactic nuclei. He was also a highly respected historian of astronomy who shed new light on 19th- and 20th-century astronomy. Don was born in Cincinnati, Ohio, on 13 July 1924. Both of his parents were of German descent and valued hard work, education, and science. They both completed their high-school education at night while working full-time during the day. His father eventually became a professor of electrical engineering at the University of Cincinnati. Don's plan to become an astronomer was put on hold when the Japanese attacked Pearl Harbor in 1941. After graduation from high school, Don joined the United States Army and trained as a meteorologist, taking all of the physics and mathematics courses required for a bachelor's degree in physics from the University of Chicago. He was eventually sent to islands in the Pacific Ocean but never was in harm's way. After three years of service, Don returned to Chicago to obtain his bachelor's degree in 1948, his M.S. in astronomy in 1949, and a Ph.D. in astronomy in 1952. Don's years at the University of Chicago and the University's Yerkes Observatory in Williams Bay, Wisconsin, were pivotal for his career and personal life. He came in contact with such luminaries as Otto Struve, Bengt Strömgren, Subrahmanyan Chandrasekhar, and William W. Morgan. At Yerkes, he also met and married Irene L. Hansen, a native of Williams Bay, who was employed as a member of the Yerkes staff. They had a son, William, now

  6. Pollution by oestrogenic endocrine disruptors and β-sitosterol in a south-western European river (Mira, Portugal).

    PubMed

    Rocha, Maria João; Cruzeiro, Catarina; Reis, Mário; Pardal, Miguel Ângelo; Rocha, Eduardo

    2016-04-01

    The Mira River is a Portuguese water body widely known for its wilderness and is advertised as one of the less polluted European rivers. On this presumption, the levels of endocrine-disrupting compounds (EDCs) in Mira waters were never measured. However, because environmentalists have claimed that the Mira could be moderately polluted, a range of 17 EDCs were measured not only at the estuary but also along the river. The targeted EDCs included natural and pharmaceutical oestrogens (17β-oestradiol, oestrone and 17α-ethynylestradiol), industrial/household pollutants (octylphenols, nonylphenols and their monoethoxylates and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein) and the phytosterol sitosterol (SITO). For this propose, waters from six sampling sites were taken every 2 months, over a 1-year period (2011), and analysed by gas chromatography-mass spectrometry. Unexpectedly high levels of oestrogens and of industrial/household pollutants were measured at all sampling sites, including those located inside natural protected areas. Indeed, the annual average sum of EDCs was ≈57 ng/L for oestrogens and ≈1.3 μg/L for industrial/household chemicals. In contrast, the global average levels of phytoestrogens (≈140 ng/L) and of SITO (≈295 ng/L) were lower than those reported worldwide. The EDC concentrations were normalised for ethynylestradiol equivalents (EE2eq). In view of these, the oestrogenic load of the Mira River attained ≈47 ng/L EE2eq. In addition, phosphates were above legal limits at both spring and summer (>1 mg/L). Overall, data show EDCs at toxicant relevant levels in the Mira and stress the need to monitor rivers that are allegedly less polluted. PMID:27004433

  7. SMOS L1PP Performance Analysis with MIRAS Data from Validation Campaigns

    NASA Astrophysics Data System (ADS)

    Castro, R.; Barbosa, J.; Candeias, H.; Catarino, N.; Freitas, J.; Freitas, S.; Gutierrez, A.; Lucas, B.

    2009-04-01

    Deimos Engenharia has been involved in the SMOS mission since 2003 and has played an important role in the project since then. The two main software packages that Deimos Engenharia has maintained during the past years are a) the Level 1 Processor Prototype (L1PP), where the scientific algorithms are implemented and verified; and b) the SMOS End-to-end Performance Simulator - Ground Segment (SEPS-GS), derived from the original simulator from the Universitat Politécnica de Catalunya (UPC) but with emphasis on Ground Segment capabilities. These tools have been widely used by the scientific community, as well as by the Deimos Engenharia's SMOS team, in preparation for the operational period of the SMOS mission. In May/June 2007, Image Validation Tests (IVT) were conducted in the Maxwell Anechoic Chamber at ESA/ESTEC, in Noordwijck. This campaign provided the first set of data available measured by the MIRAS instrument itself, instead of being generated by the SEPS-GS simulator. This data has now been extensively analysed by Deimos Engenharia, and several studies have been performed and released, aiming at the validation and improvement of the L1PP. The results have shown to be in good agreement with the theoretical expectations, confirming that the L1PP is well prepared for the upcoming commissioning phase. The IVT data analysis was mainly based on the study of reconstructed flat scenes obtained in the Maxwell chamber. This allowed the test of several optional calibration algorithms and alternative methods for image reconstruction and foreign sources removal. The L1PP was adapted specifically for the analysis of IVT data, through the implementation of a Near Field reconstruction algorithm. The Level 1 processing has then been evaluated with real data taken with MIRAS. The results have been consistently better than expected, since the theoretically predicted value for the radiometric accuracy (or pixel bias) of an averaged flat scene is estimated to be roughly 1 K and

  8. Development of LM10-MIRA LOX/LNG expander cycle demonstrator engine

    NASA Astrophysics Data System (ADS)

    Rudnykh, Mikhail; Carapellese, Stefano; Liuzzi, Daniele; Arione, Luigi; Caggiano, Giuseppe; Bellomi, Paolo; D'Aversa, Emanuela; Pellegrini, Rocco; Lobov, S. D.; Gurtovoy, A. A.; Rachuk, V. S.

    2016-09-01

    This article contains results of joint works by Konstruktorskoe Buro Khimavtomatiki (KBKhA, Russia) and AVIO Company (Italy) on creation of the LM10-MIRA liquid-propellant rocket demonstrator engine for the third stage of the upgraded "Vega" launcher.Scientific and research activities conducted by KBKhA and AVIO in 2007-2014 in the frame of the LYRA Program, funded by the Italian Space Agency, with ELV as Prime contractor, and under dedicated ASI-Roscosmos inter-agencies agreement, were aimed at development and testing of a 7.5 t thrust expander cycle demonstrator engine propelled by oxygen and liquid natural gas (further referred to as LNG).

  9. Time variations of IR spectra and dust properties in carbon-rich Mira variables

    NASA Astrophysics Data System (ADS)

    Sung, Hyun-Il; Lee, Sang-Gak

    2004-05-01

    We have studied variations of physical parameters in the circumstellar enveloped of carbon rich Mira variables at different pulsation phases. After comparing the ISO/SWS spectra of these stars with spectral energy distributions calculated from models, we could find the best-fitted parameters for the physical state of the dust envelope at each phase. The variations of the parameters effective temperature, fraction of SiC grains, mass-loss rates, and inner radius of shell, are found to have nearly the same trend as that of the light curve. The other parameters grain size, optical depth, radius of central star and dust temperature at the inner boundary of envelope, are inversely varying to the light curve.

  10. [It is better to die on your feet than live on your knees: Emilio Mira y López and the social revolution].

    PubMed

    Mülberger, Annette; Jacó-Vilela, Ana Maria

    2007-01-01

    Although the socialist ideology of the Catalan psychiatrist Emilio Mira y López (1896-1964) is relatively well known, his psychological-political contribution has been ignored. The aim of this paper is two-fold. First, Mira's psychological analysis of the social revolution is situated in the historical context of Catalonia and Spain before Franco's Dictatorship, taking account of biographical and political as well as scientific and cultural aspects. Second, the way in which Mira related psychology to politics is explored by examining the extent to which his scientific work reflected his socialist ideas. PMID:18351169

  11. Parallax of a Mira variable R Ursae Majoris studied with astrometric VLBI

    NASA Astrophysics Data System (ADS)

    Nakagawa, Akiharu; Kurayama, Tomoharu; Matsui, Makoto; Omodaka, Toshihiro; Honma, Mareki; Shibata, Katsunori M.; Sato, Katsuhisa; Jike, Takaaki

    2016-08-01

    We have measured an annual parallax of the Mira variable R Ursae Majoris (R UMa) with the VLBI Exploration for Radio Astronomy (VERA). From the monitoring VLBI observations over a span of about two years, we detected H2O maser spots in the LSR velocity range from 37 to 42 km s-1. We derived an annual parallax of 1.97 ± 0.05 mas, and this gives a corresponding distance of 508 ± 13 pc. The VLBI maps revealed 72 maser spots distributed in an ˜110 au area around the expected stellar position. Circumstellar kinematics of the maser spots were also revealed by subtracting a systemic motion in the Hipparcos catalog from proper motions of each maser spot derived from our VLBI observations. Infrared photometry was also conducted to measure a K-band apparent magnitude, and we obtained a mean magnitude of mK = 1.19 ± 0.02 mag. Using the trigonometric distance, mK is converted to a K-band absolute magnitude of MK = -7.34 ± 0.06 mag. This result gives a much more accurate absolute magnitude for R UMa than previously provided. We solved a zero-point of the MK-log P relation for the Galactic Mira variables and obtained a relation of MK = -3.52 log P + (1.09 ± 0.14). Other long-period variables, including red supergiants, whose distances were determined with astrometric VLBI, were also compiled to explore the different sequences of the MK-log P relation.

  12. STS-92 - Landing at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    2000-01-01

    With its drag parachute deployed to help slow it down, the Space Shuttle Discovery rolls down the runway after landing at Edwards Air Force Base in Southern California at the conclusion of mission STS-92 on October 24, 2000. STS-92 was the 100th mission since the fleet of four Space Shuttles began flying in 1981. (Due to schedule changes, missions are not always launched in the order that was originally planned.) The almost 13-day mission, the 46th Shuttle mission to land at Edwards, was the last construction mission for the International Space Station prior to the first scientists taking up residency in the orbiting space laboratory the following month. The seven-member crew on STS-92 included mission specialists Koichi Wakata, Michael Lopez-Alegria, Jeff Wisoff, Bill McArthur and Leroy Chiao, pilot Pam Melroy and mission commander Brian Duffy.

  13. New antenna feed revitalizes Space Shuttle tracker at NASA Edwards

    NASA Technical Reports Server (NTRS)

    Wrin, J. W.; Sullivan, A.

    1984-01-01

    An account is given of the upgrading of a 12-ft-diameter single-channel monopulse tracking system, which had been relegated to slaved backup status at NASA Edwards, to support research flights for Ames Dryden Research Center and for tracking orbital passes of the Space Shuttle and Shuttle landings both at Edwards and at White Sands. The improved system is now a stand-alone telemetry tracking system. A new conical scanning feed (known as Radscan) replaces the single channel monopulse feed in the upgraded system. Where previously the system would not autotrack at elevation angles below 5 degrees, it now automatically acquires the Space Shuttle when it appears on the horizon and autotracks from approximately 2 degrees in elevation to touchdown, and does so virtually unattended.

  14. Brief Reflections on Edward Teller's Scientific Life at Livermore

    NASA Astrophysics Data System (ADS)

    Tarter, C. Bruce

    2010-01-01

    As George Miller indicated in his welcoming remarks the theme of today's symposium is the scientific and educational legacy of Edward Teller. I will say a few words about his activities in those areas during the 50 plus years he spent at the Livermore Laboratory, Sig Hecker will touch on his re-engagement with the Los Alamos Laboratory during the last couple of decades of his life, and then we will show you a video with excerpts from the Memorial Service we held on November 3, 2003 after he passed away in September of that year. On the video you will get to hear comments by many of the people who knew Edward throughout much of his life, Hans Bethe, John Wheeler, Harold Agnew and many others ...

  15. Bibliography of the Edwards Aquifer, Texas, through 1993

    USGS Publications Warehouse

    Menard, J.A.

    1995-01-01

    The bibliography comprises 1,022 multidisciplinary references to technical and general literature for the three regions of the Edwards aquifer, Texas-San Antonio area; Barton Springs segment, Austin area; and northern segment, Austin area. The references in the bibliography were compiled from computerized data bases and from published bibliographies and reports. Dates of references range from the late 1800's through 1993. Subject and author indexes are included.

  16. STS-84 M.S Edward Tsang Lu suits up

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-84 Mission Specialist Edward Tsang Lu gives a 'thumbs up' as he dons his launch and entry suit during final prelaunch preparations in the Operations and Checkout Building. This will be Lus first space flight. Lu and six other crew members will depart shortly for Launch Pad 39A, where the Space Shuttle Atlantis awaits liftoff on a mission to dock with the Russian Space Station Mir.

  17. F-1 Engine Test Firing at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    1962-01-01

    This photograph depicts the Rocketdyne static firing of the F-1 engine at the towering 76-meter Test Stand 1-C in Area 1-125 of the Edwards Air Force Base in California. The Saturn V S-IC (first) stage utilized five F-1 engines for its thrust. Each engine provided 1,500,000 pounds, for a combined thrust of 7,500,000 pounds with liquid oxygen and kerosene as its propellants.

  18. Astronaut Edward Gibson trains with Earth Resources Experiments Package

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Scientist-Astronaut Edward G. Gibson, Skylab 4 science pilot, turns on a switch on the control box of the S190B camera, one of the components of the Earth Resources Experiments Package (EREP). The single lens Earth Terrain Camera takes five-inch photographs. Behind Gibson is the stowed suits of Astronaut Gerald P. Carr, commander for the third manned mission. The exercise took place in the Orbital Workshop one-G trainer at JSC.

  19. Selected Scientific and Technical Contributions of Edward C. Polhamus

    NASA Technical Reports Server (NTRS)

    Luckring, James M.

    2016-01-01

    Edward C. Polhamus joined the NACA Langley Research Center staff in 1944 and was active in a broad range of aerodynamic research related to high-speed aircraft technology, aerodynamic prediction methods, and cryogenic wind-tunnel development. This lecture will focus on his 'leading-edge suction analogy' for the prediction of vortex-lift effects on slender wings. Briefer treatment of his contributions to variable-sweep aircraft and cryogenic wind tunnels is also included.

  20. Robert G Edwards and the Roman Catholic Church.

    PubMed

    Benagiano, Giuseppe; Carrara, Sabina; Filippi, Valentina

    2011-06-01

    The Roman Catholic Church reacted negatively to the announcement that the Nobel Prize for Medicine had been awarded to Robert G Edwards. Thirty-three years ago, Cardinal Albino Luciani, on the eve of his election to become Pope, stated that, whereas progress is certainly a beautiful thing, mankind has not always benefited from progress. Catholic criticism has raised seven points: (i) God wants human life to begin through the 'conjugal act' and not artificially; (ii) artificial interventions at the beginning of human life are dangerous and ethically unacceptable; (iii) limits can be imposed even upon an individual's freedom to achieve a legitimate goal, such as having a child within marriage; (iv) the massive loss of preimplantation embryos characterizing IVF must be considered as a tragic loss of 'nascent' human persons; (v) Edwards bears a moral responsibility for all subsequent developments in assisted reproduction technology and for all 'abuses' made possible by IVF; (vi) there can be deleterious consequences for offspring of assisted reproduction technology; and (vii) Edwards' discovery did not eliminate the causes of infertility. This article elaborates from the Roman Catholic perspective on each of these points, some of which are found to be more substantial than others. PMID:21498122

  1. Photographic copy of photograph, view looking northeast of JPL Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, view looking northeast of JPL Edwards Test Station as it looked in 1945. To the immediate right of the Test Stand 'A' tower stands a concrete monitor building or blockhouse (now Building 4203/E-4) for observation and control of tests. Other frame buildings housed workshop and administrative functions. Long structure behind automobiles was designated 4207/E-8 and was used for instrument repair and storage, a cafeteria, machine and welding shops. To the immediate south of 4207/E-8 were 4200/E-1 (used as an office and photographic laboratory) and 4205/E-6 (guardhouse, with fire extinguisher mounted on it). To the northeast of 4205/E-6 was 4204/E-5 (a propellant storage dock, with shed roof). Buildings 4200/E-1, 4205/E-6 and 4207/E-8 were demolished in 1983. Note the absence of trees. (JPL negative no. 383-1297, July 1946) - Jet Propulsion Laboratory Edwards Facility, Edwards Air Force Base, Boron, Kern County, CA

  2. Geomorphology and hydrogeology of the Edwards Plateau karst, central Texas

    NASA Astrophysics Data System (ADS)

    Kastning, E. H., Jr.

    The Edwards Plateau is one of the largest continuous karst regions of the United States; yet, its geomorphic evolution has previously received little systematic study. The overall objectives of this investigation are to: (1) describe the physical characteristics of karst features, (2) determine which geomorphic and hydrogeologic controls and processes have governed their development, and (3) relate genesis of karst spatially and chronologically to the geomorphic evolution of the Edwards Plateau. Cavern development provides a record of evolution of karst and the development of major carbonate aquifers of the region. Some control on cavern development are region-wide; nevertheless, many caves exhibit characteristics that suggest a strong influence of local factors. Development of cave chambers and passages has responded to the lithic character of bedrocks. Solution conduits were guided by variations in calcite and dolomite content, thickness of strata, and frequency of bedding-plane partings. This is particularly true of the Glen Rose Formation, limestone beds of the Edwards Group, and the Gorman Formation, the three principal cave-forming units.

  3. The origin and evolution of short-period Miras in the solar neighborhood: Constraints on the life cycle of old stars

    NASA Technical Reports Server (NTRS)

    Jura, M.

    1994-01-01

    The spatial distribution of the short-period (P less than 300 days) oxygen-rich Miras in the solar neighborhood can be fitted with an exponential scale height above the Galactic plane of about 600 pc. Using the Gliese catalog of local main-sequence stars, we estimate that the density of suitable G-type progenitor dwarfs within 20 pc of the Sun for these short-period Miras is 6 x 10(exp -4)/cu pc. The portion of the H-R diagram near the main-sequence turnoff of these velocity-selected Gliese stars is intermediate between that of the old open cluster NGC 188 and that of the metal-rich globular cluster, 47 Tuc. We infer that the main-sequence progenitors of the short-period Miras have masses near 1.0 solar mass, and we estimate that these Miras have ages approximately 9 x 10(exp 9). We also identify a few old disk red giants in the neighborhood of the Sun. On the basis of very limited information, we estimate that the total amount of mass lost from these stars during their first ascent up the red giant branch is less than or equal to 0.1 solar mass. We derive a duration of the short-period Mira phase of close to 5 x 10(exp 5) yr. This estimate for the duration of the short period Mira phase is longer than our estimate of 2 x 10(exp 5) yr for the duration of the Mira phase for stars with periods longer than 300 days. From their infrared colors, we estimate a typical mass-loss rate from the short-period Miras of approximately 1 x 10(exp -7) solar mass/yr.

  4. Behavior of Mira Variables in Bandstrength-Color Diagrams. Comparison of Dynamic Models with Calibrated Spectral Scans

    NASA Astrophysics Data System (ADS)

    Wing, R. F.; Alvarez, R.; Plez, B.; Yuan, Y.

    We compare 26-color scanner observations of Mira variables (Wing 1967, recently rereduced and recalibrated) with model calculations. The measurements were made through a 30 AA exit slot at 26 selected wavelengths between 7800 and 11000 AA. They include the best available continuum points, and points sensitive to the presence of bands of TiO, VO, CN, ZrO, and H_2O. We present molecular bandstrength-color diagrams in which the variables execute loops. This behavior was first shown in a review article (Spinrad & Wing 1969) and discussed further by Wing (1980). Here we present comparisons with model calculations, following the work of Alvarez & Plez (1998). Detailed synthetic spectra from hydrostatic models reproduce the observed colors. The loops followed by the Mira variables in color-color diagrams are reasonably well reproduced by hydrodynamic model atmospheres. We show the effects of pulsation on the behavior of the different molecular bands seen in this spectral region.

  5. MIRAS characterization and monitoring during the SMOS In-Orbit Commissioning Phase

    NASA Astrophysics Data System (ADS)

    Corbella, I.; Torres, F.; Martin-Neira, M.; Duffo, N.; González-Gambau, V.; Camps, A.; Vall-Llossera, M.

    2009-04-01

    1 Introduction The Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) is the single payload of the Soil Moisture and Ocean Salinity (SMOS) mission. The instrument was completed in early 2007 and thoroughly tested both in anechoic chamber and vacuum thermal chamber during 2007. It was integrated to the platform in early 2008 and re-tested, including compatibility, during 2008. At present, the whole satellite is stowed and waiting to be launched during 2009. In two weeks after launch, the satellite will be in the final orbit with all deployments completed. Then the In-Orbit Commissioning Phase will start, having an estimated duration of 5.5 months. During this phase, the instrument modes of operation will be systematically checked and the calibration parameters will be fully characterized in real conditions. Also, the first brightness temperature images will be obtained in order to assess the overall retrieval procedures including inversion. In the end, the objective of the In-Orbit Commissioning Phase is to provide verification that the payload meets the scientific requirements of the mission. The general design and planning of the In-Orbit Commissioning Phase is given in [1]. This abstract presents the foreseen activities to be performed during this phase by the UPC team. Just after the start of the In-Orbit Commissioning Phase, the instrument will be commanded to perform a sequence of operations oriented at providing a full characterization in terms of calibration parameters. The idea is to reproduce the results obtained during the tests carried out on ground [2]. In particular, the following issues will be covered: Thermal Stability: To provide understanding of both the intra-orbit and inter-orbit temperature variations. The instrument will be continuously operating during a number of orbits while all temperature sensors being monitored. Electrical Stability: To re-compute all internal calibration parameters (gains, offsets, receiver noise temperatures

  6. Effect of hinge gap width of a St. Jude medical bileaflet mechanical heart valve on blood damage potential--an in vitro micro particle image velocimetry study.

    PubMed

    Jun, Brian H; Saikrishnan, Neelakantan; Arjunon, Sivakkumar; Yun, B Min; Yoganathan, Ajit P

    2014-09-01

    The hinge regions of the bileaflet mechanical heart valve (BMHV) can cause blood element damage due to nonphysiological shear stress levels and regions of flow stasis. Recently, a micro particle image velocimetry (μPIV) system was developed to study whole flow fields within BMHV hinge regions with enhanced spatial resolution under steady leakage flow conditions. However, global velocity maps under pulsatile conditions are still necessary to fully understand the blood damage potential of these valves. The current study hypothesized that the hinge gap width will affect flow fields in the hinge region. Accordingly, the blood damage potential of three St. Jude Medical (SJM) BMHVs with different hinge gap widths was investigated under pulsatile flow conditions, using a μPIV system. The results demonstrated that the hinge gap width had a significant influence during the leakage flow phase in terms of washout and shear stress characteristics. During the leakage flow, the largest hinge gap generated the highest Reynolds shear stress (RSS) magnitudes (~1000 N/m²) among the three valves at the ventricular side of the hinge. At this location, all three valves indicated viscous shear stresses (VSS) greater than 30 N/m². The smallest hinge gap exhibited the lowest level of shear stress values, but had the poorest washout flow characteristics among the three valves, demonstrating propensity for flow stasis and associated activated platelet accumulation potential. The results from this study indicate that the hinge is a critical component of the BMHV design, which needs to be optimized to find the appropriate balance between reduction in fluid shear stresses and enhanced washout during leakage flow, to ensure minimal thrombotic complications. PMID:24976188

  7. Reduction of procoagulant potential of b-datum leakage jet flow in bileaflet mechanical heart valves via application of vortex generator arrays.

    PubMed

    Murphy, David W; Dasi, Lakshmi P; Vukasinovic, Jelena; Glezer, Ari; Yoganathan, Ajit P

    2010-07-01

    Current designs of bileaflet mechanical heart valves put patients at an increased risk of thromboembolism. In particular, regurgitant flow through the b-datum line is associated with nonphysiologic flow characteristics such as elevated shear stresses, regions of recirculation, and increased mixing, all of which may promote thrombus formation. We have previously shown that passive flow control in the form of vortex generators mounted on the downstream leaflet surfaces can effectively diminish turbulent stresses. The objective of the current work is thus to determine the effect of vortex generators on the thromboembolic potential of the b-datum line leakage jet and to correlate that effect with the vortex generator-induced changes to the flow structure. Flow experiments were performed using a steady model of the transient b-datum line jet. These experiments encompassed flow visualization to gain an overall picture of the flow system, particle image velocimetry to quantify the flow field in detail, and in vitro experiments with human blood to quantify thrombus formation in response to the applied passive flow control. Thrombus formation was quantified over time by an assay for thrombin-antithrombin III (TAT III). In comparing results with and without vortex generators, significantly lower mean TAT III levels were observed at one time point for the case with vortex generators. Also, the TAT III growth rate of the case with vortex generators was significantly lower. While no differences in jet spreading were found with and without vortex generators, lower peak turbulent stresses were observed for the case with vortex generators. The results thus demonstrate the potential of applying passive flow control to cardiovascular hardware in order to mitigate the hemodynamic factors leading to thrombus formation. PMID:20590289

  8. Ground winds and winds aloft for Edwards AFB, California (1978 revision)

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.; Brown, S. C.

    1978-01-01

    Ground level runway wind statistics for the Edwards AFB, California area are presented. Crosswind, headwind, tailwind, and headwind reversal percentage frequencies are given with respect to month and hour for the two major Edwards AFB runways. Also presented are Edwards AFB bivariate normal wind statistics for a 90 degree flight azimuth for altitudes 0 through 27 km. Wind probability distributions and statistics for any rotation of axes can be computed from the five given parameters.

  9. John Goodricke, Edward Pigott, and Their Study of Variable Stars

    NASA Astrophysics Data System (ADS)

    French, Linda M.

    2011-05-01

    John Goodricke (1764-1786) and Edward Pigott (1753-1825) are credited with determining the first accurate periods for several important variable stars. Goodricke's name is associated with the determination of the period of the eclipsing binary Algol (Beta Persei); for this he was awarded the Copley Prize of the Royal Society of London. He also determined the periods of the contact binary Beta Lyrae and of Delta Cephei, the prototype Cepheid variable. Around the same time, Edward Pigott obtained the period of Eta Aquilae, another Cepheid. In actuality, the two collaborated on all these observations; today we would call them co-discoverers. Goodricke is the better known of the two, in part because he won the Copley Medal, in part because of his tragically short life, and in part because he was deaf. Edward Pigott was the more experienced observer, having worked with his father Nathaniel on determining the longitudes of several cities on the Continent. Evidence shows, however, that Goodricke had some astronomical experience while a student at the Warrington Academy. The journals of the two show that they developed a partnership that made the most of both their talents over the brief time (less than five years) they worked together before Goodricke's death. Today, the two are remembered as having suggested eclipses as the cause for the periodic dimming of Algol. This explanation is accepted today as the correct one. In their day, however, most eminent astronomers believed that starspots were a more likely cause for the dimming. By the time of John Goodricke's death, he seems to have accepted that explanation as well. A study of the work of Goodricke and Pigott contains many lessons for today's observers of variable stars. This work was supported by an AAS Small Research Grant and by the Pollack Award of the Dudley Observatory.

  10. John Goodricke, Edward Pigott, and Their Study of Variable Stars

    NASA Astrophysics Data System (ADS)

    French, Linda M.

    2012-06-01

    John Goodricke and Edward Pigott, working in York, England, between 1781 and 1786, determined the periods of variation of eclipsing binaries such as Algol and Beta Lyrae and speculated that the eclipses of Algol might be caused by a "dark body," perhaps even a planet. They also determined the periods of variation of the first two known Cepheid variables, the stars whose period-luminosity relation today enables astronomers to determine distances to distant galaxies. Goodricke holds special interest because he was completely deaf and because he died at the age of 21. The lives and work of these two astronomers are described.

  11. Minimum flow unit installation at the South Edwards Hydro Plant

    SciTech Connect

    Bernhardt, P.; Bates, D.

    1995-12-31

    Niagara Mohawk Power Corp. owns and operates the 3.3 MW South Edwards Hydro Plant in Northern New York. The FERC license for this plant requires a minimum flow release in the bypass region of the river. NMPC submitted a license amendment to the FERC to permit the addition of a minimum flow unit to take advantage of this flow. The amendment was accepted, permitting the installation of the 236 kw, 60 cfs unit to proceed. The unit was installed and commissioned in 1994.

  12. Edwards Thermodynamics for a Driven Athermal System with Dry Friction

    NASA Astrophysics Data System (ADS)

    Gradenigo, Giacomo; Ferrero, Ezequiel E.; Bertin, Eric; Barrat, Jean-Louis

    2015-10-01

    We obtain, using semianalytical transfer operator techniques, the Edwards thermodynamics of a one-dimensional model of blocks connected by harmonic springs and subjected to dry friction. The theory is able to reproduce the linear divergence of the correlation length as a function of energy density observed in direct numerical simulations of the model under tapping dynamics. We further characterize analytically this divergence using a Gaussian approximation for the distribution of mechanically stable configurations, and show that it is related to the existence of a peculiar infinite temperature critical point.

  13. STS-66 Atlantis Landing and Chute Deployment at Edwards

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Space Shuttle Atlantis lands with its drag chute deployed on runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) November 14, 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather.

  14. A Stellar movie: VLBA monitoring of SiO masers around the Mira variable TX Cam

    NASA Astrophysics Data System (ADS)

    Diamond, P. J.; Kemball, A. J.

    1998-12-01

    Single dish monitoring of SiO masers around stars have revealed strong, cyclic variations of the spectra. The peak flux of the SiO masers appears to occur at a phase of 0.2 after the optical maximum, from phase 0.3 to 0.8 the average velocity of the spectrum appears to be slightly redshifted with respect to the mean velocity indicating infall of material. Recently Boboltz et al (1997) showed, using VLBA observations, that for the star R Aquarii the SiO masers were infalling at 4.3 km/s from optical phase 0.78 to 1.04. To date this has been the basis of our understanding of the nature of SiO variability. We have been performing regular VLBA observations of the SiO masers around the Mira variable TX Cam. We have been taking data every two weeks and will eventually obtain 50 epochs covering 1.25 cycles of the star's phase. We shall present a movie of the structural changes occurring for the first 80% of our program, covering phases 0.3 to 1.3. We see complex structural changes including both infalling and outflowing gas. We also have information on the changing polarization structure of the masers. We shall discuss our observations in the context of the hydrodynamic models of Bowen.

  15. FE Line Diagnostics of Multiply Shocked Stellar Atmospheres: The Mira S. Carinae

    NASA Technical Reports Server (NTRS)

    Bookbinder, Jay

    1997-01-01

    Extensive LWP-HI spectra were obtained of the Mira S Car at a rapid time cadence as compared with the shock cycle time of S Car. These spectra were obtained in an attempt to understand the velocity structures in the shocked wind using the fluoresced iron lines. Data analysis of the IUE observations, which included the primary calibration of all of the IUE spectra obtained of S Car, was carried out. In addition, line identifications, flux calculations, background subtractions, and line profile analysis as a function of S Car's pulsational phase were performed. The database incorporated all line identifications as a function of pulsation phase for all IUE LWP-HI observations to date of S Car. At least 45 separate iron line features are identified in the S Car spectrum at one or more phases of the shock cycle, including those due to Fe II (UV 161) which is pumped by three different iron lines; Fe I(UV 44) which is pumped by the Mg II k line. Other strong multiplets that have been identified include UV(1), UV(2), UV(5), UV(32), UV(60), UV(63), UV(161), UV(207), and UV(399). Over 300 weaker lines have also been tentatively identified with Fe line transitions.

  16. Morphology and kinematics of the gas envelope of the Mira binary W Aquilae

    NASA Astrophysics Data System (ADS)

    Thi Hoai, Do; Tuyet Nhung, Pham; Diep, Pham Ngoc; Thi Phuong, Nguyen; Tuan-Anh, Pham; Thi Thao, Nguyen; Darriulat, Pierre

    2016-07-01

    We analyse ALMA observations of the 12CO(3-2) emission of the circumstellar envelope (CSE) of the Mira variable binary star W Aql. These provide, for the first time, spatially resolved Doppler velocity spectra of the CSE up to angular distances to the central star of ∼ 5″ (meaning some 2000 AU). The exploratory nature of the observations (only five minutes in each of two different configurations) does not allow for a detailed modelling of the properties of the CSE but provides important qualitative information on its morphology and kinematics. Emission is found to be enhanced along an axis moving from east/west to north-east/south-west when the angular distance from the central star projected on the plane of the sky increases from zero to four arcseconds. In parallel, the Doppler velocity distribution displays asymmetry along an axis moving from east/west to north-west/south-east. The results are discussed in the context of earlier observations, in particular of the dust morphology. ) operated by the NAOJ.

  17. Edwards polaron formation : From one to three dimensions

    NASA Astrophysics Data System (ADS)

    Chakraborty, M.; Mohanta, N.; Taraphder, A.; Min, B. I.; Fehske, H.

    2016-04-01

    Employing a self-consistent (optimized) variational diagonalization scheme, we investigate the formation of polaronic quasiparticles in a spinless fermion-boson transport model that couples the movement of charge carriers to fluctuations and correlations of a background medium. The background is parameterized by bosonic degrees of freedom. The variational fermion-boson Hilbert space is constructed to achieve high accuracy in one to three spatial dimensions with modest computational requirements. To characterize the ground-state properties of the Edwards model in the single-particle sector, we present exact numerical results for the polaron band dispersion, quasiparticle weight, Drude weight, mass enhancement, and the particle-boson correlations in a wide parameter regime. In the Edwards model, transport will be quasifree, diffusive or boson-assisted in the weakly fermion-boson coupled, fluctuation-dominated or strongly correlated regimes, respectively. Thereby correlated transport is not only assisted but also limited by the bosonic excitations. As a result, the Drude weight remains finite even in the limit of very small boson frequencies. For a strongly correlated background, closed loops are important, in any dimension, to generate a finite effective particle mass even when the free fermion has an infinite mass.

  18. First-Ever Census of Variable Mira-Type Stars in Galaxy Outside the Local Group

    NASA Astrophysics Data System (ADS)

    2003-05-01

    First-Ever Census of Variable Mira-Type Stars in Galaxy Outsidethe Local Group Summary An international team led by ESO astronomer Marina Rejkuba [1] has discovered more than 1000 luminous red variable stars in the nearby elliptical galaxy Centaurus A (NGC 5128) . Brightness changes and periods of these stars were measured accurately and reveal that they are mostly cool long-period variable stars of the so-called "Mira-type" . The observed variability is caused by stellar pulsation. This is the first time a detailed census of variable stars has been accomplished for a galaxy outside the Local Group of Galaxies (of which the Milky Way galaxy in which we live is a member). It also opens an entirely new window towards the detailed study of stellar content and evolution of giant elliptical galaxies . These massive objects are presumed to play a major role in the gravitational assembly of galaxy clusters in the Universe (especially during the early phases). This unprecedented research project is based on near-infrared observations obtained over more than three years with the ISAAC multi-mode instrument at the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory . PR Photo 14a/03 : Colour image of the peculiar galaxy Centaurus A . PR Photo 14b/03 : Location of the fields in Centaurus A, now studied. PR Photo 14c/03 : "Field 1" in Centaurus A (visual light; FORS1). PR Photo 14d/03 : "Field 2" in Centaurus A (visual light; FORS1). PR Photo 14e/03 : "Field 1" in Centaurus A (near-infrared; ISAAC). PR Photo 14f/03 : "Field 2" in Centaurus A (near-infrared; ISAAC). PR Photo 14g/03 : Light variation of six variable stars in Centaurus A PR Photo 14h/03 : Light variation of stars in Centaurus A (Animated GIF) PR Photo 14i/03 : Light curves of four variable stars in Centaurus A. Mira-type variable stars Among the stars that are visible in the sky to the unaided eye, roughly one out of three hundred (0.3%) displays brightness variations and is referred to by astronomers as a

  19. 77 FR 6595 - In the Matter of Edward G. Johnson; Confirmatory Order (Effective Immediately)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... under 10 CFR 2.315(c), must be filed in accordance with the NRC E-Filing rule (72 FR 49139, August 28... COMMISSION In the Matter of Edward G. Johnson; Confirmatory Order (Effective Immediately) I Mr. Edward G... must file an exemption request, in accordance with 10 CFR 2.302(g), with their initial paper...

  20. A long telephoto lens captured Space Shuttle Endeavour landing at Edwards Air Force Base, California

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A long telephoto lens captured Space Shuttle Endeavour landing at Edwards Air Force Base, California, on May 1, 2001. NASA's Dryden Flight Research Center at Edwards would subsequently service the shuttle and mount it on a 747 for the ferry flight to the Kennedy Space Center in Florida.

  1. The discovery of a second species of Mallophthiria Edwards (Diptera, Bombyliidae, Crocidiinae) from Chile.

    PubMed

    Yamaguchi, Carolina; Lamas, Carlos José Einicker

    2014-01-01

    The Neotropical genus Mallophthiria Edwards is restricted to Chile (Concepción and Choapa) and comprises M. lanata Edwards, 1930 and M. elguetai sp. nov. The new species is described and illustrations of the external morphology of adults and male and female terminalia are also included. PMID:25543730

  2. Credit USAF. Original housed in the Photograph Files, AFFTC/HO, Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Credit USAF. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. View of Motor Repair Shop (originally T-16), probably shortly after completion in 1943 - Edwards Air Force Base, North Base, Motor Repair Shop T-16, Third & C Streets, Boron, Kern County, CA

  3. 2. Credit USAF, 1943. Original housed in the AFFTC/HO, Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Credit USAF, 1943. Original housed in the AFFTC/HO, Edwards AFB, California. View looks north northwest at south and east facades of hangar as it nears completion. - Edwards Air Force Base, North Base, Hangar No. 1, First & B Streets, Boron, Kern County, CA

  4. Phenotypic extremes in liveborn monozygotic twins with mosaic Edwards syndrome.

    PubMed

    Bussmann, Neidin; Cunningham, Katie; Green, Andrew; Ryan, C Anthony

    2015-01-01

    Mosaic trisomy 18 (Edwards syndrome) in monozygotic diamniotic liveborn twins is rare. We describe such a case involving preterm male infants. Although both infants had a low percentage of trisomy 18 cells in peripheral blood leucocytes, their varied phenotypic presentation of mosaic trisomy 18 resulted in one twin surviving, with the other twin's demise at 1 month of age. Despite the presence of trisomy 18 in peripheral leucocytes, further analysis of a buccal smear and skin biopsy of the surviving twin did not show evidence of trisomy 18. Establishing such diagnoses in a timely manner is imperative for the child, parents and clinicians. The clinical course of these twins reflects the unpredictable prognosis associated with the diagnosis of mosaic trisomy 18, and emphasises the challenges that can be encountered when counselling parents. PMID:26561224

  5. A psychoanalytic study of Edward de Vere's The Tempest.

    PubMed

    Waugaman, Richard M

    2009-01-01

    There is now abundant evidence that Freud was correct in believing Edward de Vere (1550-1604) wrote under the pseudonym "William Shakespeare." One common reaction is "What difference does it make?" I address that question by examining many significant connections between de Vere's life and The Tempest. Such studies promise to bring our understanding of Shakespeare's works back into line with our usual psychoanalytic approach to literature, which examines how a great writer's imagination weaves a new creation out of the threads of his or her life experiences. One source of the intense controversy about de Vere's authorship is our idealization of the traditional author, about whom we know so little that, as Freud noted, we can imagine his personality was as fine as his works. PMID:20001197

  6. Evaluation of the Edwards Lifesciences SAPIEN transcatheter heart valve.

    PubMed

    Minha, Sa'ar; Waksman, Ron

    2014-11-01

    Severe aortic stenosis is a common valvular disease and is associated with both morbidity and mortality. Surgical aortic valve replacement was the only available therapeutic option until technological advances allowed for the development of a transcatheter heart valve system. The first available THV was the Edwards SAPIEN. The merits of this system in terms of safety and efficacy were explored in the pivotal Placement of AoRTic TraNscathetER (PARTNER) randomized trial whose results then led to the approval of this device for commercial use in the US. The valve is now indicated for inoperable patients and may be considered an alternative for surgery for high-risk patients. Two successive models, the XT and more recently the S3, were developed with the intent to improve procedural outcomes. In this article, the SAPIEN transcatheter heart valve family is described in terms of technology, scientific data and future directions. PMID:25109297

  7. Lungworm (Crenosoma vulpis) infection in dogs on Prince Edward Island.

    PubMed Central

    Bihr, T; Conboy, G A

    1999-01-01

    Crenosoma vulpis is a nematode lungworm that is highly prevalent in the red fox population of Atlantic Canada. Dogs are susceptible to infection with clinical signs consisting primarily of a chronic cough. A recent report of C. vulpis infection in 3 dogs on Prince Edward Island prompted an investigation into the importance of this parasite as a cause of chronic respiratory disease in Island dogs. A general prevalence was determined through the necropsy of dogs euthanized at the local humane society. Lungs were removed and examined for parasites using a lung flush technique. Rectal feces was collected and examined for first-stage larvae using the Baermann technique and zinc sulfate centrifugal flotation. Ten of 310 dogs (3.2%) were positive with 0-35 worms (mean = 11.0 +/- 13.4) recovered. First-stage larvae of C. vulpis were recovered in the rectal feces of the one animal in which no worms were recovered on lung flush. A second survey was conducted examining fecal samples with the Baermann technique from afebrile dogs with presenting signs of chronic cough that had no history of recent anthelmintic treatment and showed no signs of cardiac disease, based on physical examination. Fifteen of 55 dogs examined (27.3%) were definitively diagnosed as C. vulpis-positive. All of the infected dogs were treated with fenbendazole (50 mg/kg body weight, p.o. q24 h for 3-7 days). Clinical signs resolved in all of the dogs and fecal samples were negative 2-4 weeks posttreatment. It was concluded that C. vulpis infection was a significant cause of upper respiratory disease in dogs on Prince Edward Island and should be considered in all dogs with presenting signs of chronic cough. Images Figure 1. Figure 2. PMID:12001335

  8. STS-84 Mission Specialist Edward Tsang Lu in white room

    NASA Technical Reports Server (NTRS)

    1997-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-84 Mission Specialist Edward T. Lu prepares to enter the Space Shuttle Atlantis at Launch Pad 39A with help from white room closeout crew members. The fourth Shuttle mission of 1997 will be the sixth docking of the Space Shuttle with the Russian Space Station Mir. The commander is Charles J. Precourt. The pilot is Eileen Marie Collins. The five mission specialists are C. Michael Foale, Carlos I. Noriega, Edward Tsang Lu, Jean-Francois Clervoy of the European Space Agency and Elena V. Kondakova of the Russian Space Agency. The planned nine-day mission will include the exchange of Foale for U.S. astronaut and Mir 23 crew member Jerry M. Linenger, who has been on Mir since Jan. 15. Linenger transferred to Mir during the last docking mission, STS-81; he will return to Earth on Atlantis. Foale is slated to remain on Mir for about four months until he is replaced in September by STS-86 Mission Specialist Wendy B. Lawrence. During the five days Atlantis is scheduled to be docked with the Mir, the STS-84 crew and the Mir 23 crew, including two Russian cosmonauts, Commander Vasily Tsibliev and Flight Engineer Alexander Lazutkin, will participate in joint experiments. The STS-84 mission also will involve the transfer of more than 7,300 pounds of water, logistics and science equipment to and from the Mir. Atlantis is carrying a nearly 300-pound oxygen generator to replace one of two Mir units which have experienced malfunctions. The oxygen it generates is used for breathing by the Mir crew.

  9. Enhanced recharge and karst, Edwards aquifer, south central Texas

    SciTech Connect

    Hammond, W.W. Jr. . Center for Water Research)

    1993-02-01

    Enhanced recharge is a water management strategy which can add significant quantities of ground water to the available water resources of the San Antonio region by utilizing the immense storage capacity of the unconfined zone of the Edwards aquifer. The Edwards aquifer presently is the sole source of water for a population of over 1,200,000, meeting public supply, industrial, and irrigation demands over a wide area of south central Texas. Valdina Farms Sinkhole is located adjacent to Seco Creek in Medina County and is in the recharge zone of the aquifer. Initial studies indicated that the sinkholes was capable of taking flood flows from Seco Creek and functioning as a recharge structure. Stream channels in the cavern system associated with Valdina Farms Sinkhole were incised into cave deposits and flood debris was present in the caverns at some distance from the sinkhole. Chemical analyses of samples of water from the cave and from nearby wells showed nitrate concentrations that decreased with distance from the cavern. Gradient of the potentiometric surface in the vicinity of the cave was very low, indicating high values of hydraulic conductivity for the aquifer. Based on evidence from these field studies a dam was constructed in 1982 on Seco Creek and a flood diversion channel was excavated to the sinkhole. Reservoir capacity is 2 acre-feet and design recharge rate is 3.8-6.7 m[sup 3]/sec. Annual recharge at the sinkhole has varied from 0 during periods of low runoff to 12,915 acre-feet.

  10. VizieR Online Data Catalog: A study of dust nucleation in Mira. Part I. (Kaminski+, 2016)

    NASA Astrophysics Data System (ADS)

    Kaminski, T.; Wong, K. T.; Schmidt, M. R.; Muller, H. S. P.; Gottlieb, C. A.; Cherchneff, I.; Menten, K. M.; Keller, D.; Brunken, S.; Winters, J. M.; Patel, N. A.

    2016-07-01

    Files contain ALMA observations of AlO emission in Mira (omicron Ceti) in two rotational transitions, N=6-5 and 9-8, and obtained at different epochs. Spectral cubes, moment-zero maps, and spectra of the entire emission source are provided and correspond directly to those presented in the paper (Figs. 2, 3, and 5). Complementary continuum data are also included in separate files. The data were self-calibrated and therefore their absolute astrometry is inaccurate. Relative spatial coordinates should be used. (2 data files).