1,766 research outputs found

    Interview of Judith Westman by Linda Stone

    Get PDF
    Interview conducted at the Medical Heritage Center, Columbus, Ohio.In her oral history interview, Judith Westman discusses her time as a medical student and professional at the Ohio State University after her obtaining her undergraduate degree at Ohio Northern University. Westman began work at Nationwide Children's Hospital, then called Columbus Children's Hospital, and followed a career path into pediatric and prenatal genetics. After working at Children's Hospital for some time, Westman was recruited to establish a clinical cancer genetics program at the James Cancer Hospital at The Ohio State University. Westman worked in pediatrics, genetics, cancer research, and as the chair of the Admissions Committee for the College of Medicine. Westman was later appointed to the role of Associate Dean for Student Affairs and Admissions and the Dean of Medical Education at the College. In her interview, Westman discusses the philosophies she held true throughout her career

    Fraught With Friction

    Get PDF
    In this activity, a question is posed to second-grade students and they are asked to make predictions to answer it: “How will different surfaces affect the distance a toy vehicle travels?” Students observe how different surfaces affect the distance traveled by a toy car and are able to amend their predictions. They are then asked to think of reasons why the vehicle was affected the way it was. During this stage of the lesson, students are led to contemplate their understandings of science concepts, and teachers are able to assess changes in student understanding as a result of discussions and writings. Prior to this lesson, students learned how friction creates heat energy but had not discussed how the force of friction can affect the motion of an object. We broke this lesson up over three days (Table 1)

    High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes

    No full text
    International audienceThe ionospheric D-layer is a narrow bandwidth radar target often with a very small scattering cross section. The target autocorrelation function can be obtained by transmitting a series of relatively short coded pulses and computing the correlation between data obtained from different pulses. The spatial resolution should be as high as possible and the spatial side lobes of the codes used should be as small as possible. However, due to the short pulse repetition period (in the order of milliseconds) at any instant, the radar receives detectable scattered signals not only from the pulse illuminating the D-region but also from 3?5 ambiguous-range pulses, which makes it difficult to produce a reliable estimate near zero lag of the autocorrelation function. A new experimental solution to this measurement problem, using a selected set of 40-bit random codes with 4 µs elements giving 600 m spatial resolution is presented. The zero lag is approximated by dividing the pulse into two 20-bit codes and computing the correlation between those two pulses. The lowest altitudes of the E-layer are measured by dividing the pulse into 5 pieces of 8 bits, which allows for computation of 4 lags. In addition, coherent integration of data from four pulses is used for obtaining separately the autocorrelation function estimate for the lowest altitudes and in cases when the target contains structures with a long coherence time. Design details and responses of the experiment are given, and analysed test data are shown

    The EISCAT meteor code

    Get PDF
    The EISCAT UHF system has the unique capability to determine meteor vector velocities from the head echo Doppler shifts measured at the three sites. Since even meteors spending a very short time in the common volume produce analysable events, the technique lends itself ideally to mapping the orbits of meteors arriving from arbitrary directions over most of the upper hemisphere. <br><br> A radar mode optimised for this application was developed in 2001/2002. A specially selected low-sidelobe 32-bit pseudo-random binary sequence is used to binary phase shift key (BPSK) the transmitted carrier. The baud-length is 2.4 μs and the receiver bandwidth is 1.6 MHz to accommodate both the resulting modulation bandwidth and the target Doppler shift. Sampling is at 0.6 μs, corresponding to 90-m range resolution. Target range and Doppler velocity are extracted from the raw data in a multi-step matched-filter procedure. For strong (SNR>5) events the Doppler velocity standard deviation is 100–150 m/s. The effective range resolution is about 30 m, allowing very accurate time-of-flight velocity estimates. On average, Doppler and time-of-flight (TOF) velocities agree to within about one part in 10<sup>3</sup>. Two or more targets simultaneously present in the beam can be resolved down to a range separation <300 m as long as their Doppler shifts differ by more than a few km/s

    Playing Baseball On The Western Front

    Get PDF
    Photograph of a soldier in uniform.https://scholarsjunction.msstate.edu/cht-sheet-music/3120/thumbnail.jp

    What does it mean for half of an empty cavity to be full?

    Get PDF
    21 págs.; 8 figs.; 2 app.; PACS numbers: 03.67.Bg, 03.70.+k, 11.10.-z© 2015 American Physical Society. It is well known that the vacuum state of a quantum field is spatially entangled. This is true in both free and confined spaces, for example, in an optical cavity. The obvious consequence of this, however, is surprising and intuitively challenging: namely, that in a mathematical sense, half of an empty cavity is not empty. Formally this is clear, but what does this physically mean in terms of, say, measurements that can actually be made? In this paper we utilize a local quantization procedure along with the tools of Gaussian quantum mechanics to characterize the particle content in the reduced state of a subregion within a cavity and expose the spatial profile of its entanglement with the opposite region. We then go on to discuss a thought experiment in which a mirror is very quickly introduced between the regions. In so doing we expose a simple and physically concrete answer to the above question: the real excitations created by slamming down the mirror are mathematically equivalent to those previously attributed to the reduced states of the subregions. Performing such an experiment in the laboratory may be an excellent method of verifying vacuum entanglement, and we conclude by discussing different possibilities of achieving this aim.This work is supported by Spanish MICINN Projects FIS2011-29287 and CAM research consortium QUITEMAD+ S2013/ICE-2801. E. B. acknowledges support by the Michael Smith Foreign Study Supplements Program, M. del R. was supported by a CSIC JAEPREDOC grant and H. Westman was supported by the JAE-DOC 2011 CSIC & ESF program. A. D. was supported by the National Science Center, Sonata BIS Grant No. 2012/07/E/ST2/01402.Peer Reviewe

    Generalizing Optical Geometry

    Full text link
    We show that by employing the standard projected curvature as a measure of spatial curvature, we can make a certain generalization of optical geometry (Abramowicz and Lasota 1997, Class. Quantum Grav. 14 (1997) A23). This generalization applies to any spacetime that admits a hypersurface orthogonal shearfree congruence of worldlines. This is a somewhat larger class of spacetimes than the conformally static spacetimes assumed in standard optical geometry. In the generalized optical geometry, which in the generic case is time dependent, photons move with unit speed along spatial geodesics and the sideways force experienced by a particle following a spatially straight line is independent of the velocity. Also gyroscopes moving along spatial geodesics do not precess (relative to the forward direction). Gyroscopes that follow a curved spatial trajectory precess according to a very simple law of three-rotation. We also present an inertial force formalism in coordinate representation for this generalization. Furthermore, we show that by employing a new sense of spatial curvature (Jonsson, Class. Quantum Grav. 23 (2006) 1) closely connected to Fermat's principle, we can make a more extensive generalization of optical geometry that applies to arbitrary spacetimes. In general this optical geometry will be time dependent, but still geodesic photons move with unit speed and follow lines that are spatially straight in the new sense. Also, the sideways experienced (comoving) force on a test particle following a line that is straight in the new sense will be independent of the velocity.Comment: 19 pages, 1 figure. A more general analysis is presented than in the former version. See also the companion papers arXiv:0708.2493, arXiv:0708.2533 and arXiv:0708.253
    corecore