20,845 research outputs found

    Testing collapse models with levitated nanoparticles: the detection challenge

    Get PDF
    We consider a nanoparticle levitated in a Paul trap in ultrahigh cryogenic vacuum, and look for the conditions which allow for a stringent noninterferometric test of spontaneous collapse models. In particular we compare different possible techniques to detect the particle motion. Key conditions which need to be achieved are extremely low residual pressure and the ability to detect the particle at ultralow power. We compare three different detection approaches based respectively on a optical cavity, optical tweezer and a electrical readout, and for each one we assess advantages, drawbacks and technical challenges

    Subharmonics and Aperiodicity in Hysteresis Loops

    Full text link
    We show that it is possible to have hysteretic behavior for magnets that does not form simple closed loops in steady state, but must cycle multiple times before returning to its initial state. We show this by studying the zero-temperature dynamics of the 3d Edwards Anderson spin glass. The specific multiple varies from system to system and is often quite large and increases with system size. The last result suggests that the magnetization could be aperiodic in the large system limit for some realizations of randomness. It should be possible to observe this phenomena in low-temperature experiments.Comment: 4 pages, 3 figure

    Studies in matter antimatter separation and in the origin of lunar magnetism

    Get PDF
    A progress report, covering lunar and planetary research is introduced. Data cover lunar ionospheric models, lunar and planetary geology, and lunar magnetism. Wind tunnel simulations of Mars aeolian problems and a comparative study of basaltic analogs of Lunar and Martial volcanic features was discussed

    An Alternative Parameterization of R-matrix Theory

    Get PDF
    An alternative parameterization of R-matrix theory is presented which is mathematically equivalent to the standard approach, but possesses features which simplify the fitting of experimental data. In particular there are no level shifts and no boundary-condition constants which allows the positions and partial widths of an arbitrary number levels to be easily fixed in an analysis. These alternative parameters can be converted to standard R-matrix parameters by a straightforward matrix diagonalization procedure. In addition it is possible to express the collision matrix directly in terms of the alternative parameters.Comment: 8 pages; accepted for publication in Phys. Rev. C; expanded Sec. IV, added Sec. VI, added Appendix, corrected typo

    Dorsal laminectomy for treatment of cervical vertebral stenotic myelopathy in an alpaca

    Get PDF

    Starting a Streaming Video Program on a Limited Budget

    Get PDF
    Streaming videos are a desirable supplement to physical DVDs, but academic libraries may feel intimidated by the cost of adding another format to their collections. However, streaming videos can be surprisingly affordable. In the midst of a budget crunch, the librarians at Western Carolina University were able to start a streaming video program, first by selecting titles Ă  la carte, and later by launching two streaming services, Kanopy (using a demand-driven acquisitions model) and Swank (using a mediated acquisitions model). These streaming videos allow for unlimited simultaneous access by local users as well as distance-education students, and they come with performance rights that help teaching faculty prevent copyright infringement. Despite some limitations with streaming videos, the format has been well received by faculty, students, and staff

    Chromosomal Assignment of a Family of Human Oncogenes

    Get PDF
    A family of human transforming genes, previously shown to share homology with the ras family of viral oncogenes, maps to three different human chromosomes. A well-characterized mouse-human hybrid cell panel, combined with Southern blotting, was used in this study. The transforming gene of the T24 bladder carcinoma cell line maps to human chromosome 11. An oncogene isolated from the lung carcinoma cell line SK-Calu-1 maps to human chromosome 12. The third ras-related gene, cloned from SK-N-SH, a neuroblastoma cell line, maps to human chromosome 1

    The Question of Low-Lying Intruder States in 8Be^8Be and Neighboring Nuclei

    Get PDF
    The presence of not yet detected intruder states in 8Be^{8}Be e.g. a J=2+J=2^{+} intruder at 9 MeVMeV excitation would affect the shape of the ÎČ∓\beta ^{\mp }-delayed alpha spectra of 8Li^{8}Li and 8B^{8}B. In order to test the plausibility of this assumption, shell model calculations with up to 4ℏω4\hbar \omega excitations in 8Be^{8}Be (and up to 2ℏω2\hbar \omega excitations in 10Be^{10}Be) were performed. With the above restrictions on the model spaces, the calculations did not yield any low-lying intruder state in 8Be^{8}Be. Another approach -the simple deformed oscillator model with self-consistent frequencies and volume conservation gives an intruder state in 8Be^{8}Be which is lower in energy than the above shell model results, but its energy is still considerably higher than 9 MeVMeV.Comment: 16 pages (RevTeX), 1 PS figure. To appear in Phys. Rev.

    Metastability of a granular surface in a spinning bucket

    Full text link
    The surface shape of a spinning bucket of granular material is studied using a continuum model of surface flow developed by Bouchaud et al. and Mehta et al. An experimentally observed central subcritical region is reproduced by the model. The subcritical region occurs when a metastable surface becomes unstable via a nonlinear instability mechanism. The nonlinear instability mechanism destabilizes the surface in large systems while a linear instability mechanism is relevant for smaller systems. The range of angles in which the granular surface is metastable vanishes with increasing system size.Comment: 8 pages with postscript figures, RevTex, to appear in Phys. Rev.
    • 

    corecore