The non-uniform, dynamic atmosphere of Betelgeuse observed at mid-infrared wavelengths

We present an interferometric study of the continuum surface of the red supergiant star Betelgeuse at 11.15 microns wavelength, using data obtained with the Berkeley Infrared Spatial Interferometer each year between 2006 and 2010. These data allow an investigation of an optically thick layer within 1.4 stellar radii of the photosphere. The layer has an optical depth of ~1 at 11.15 microns, and varies in temperature between 1900 K and 2800 K and in outer radius between 1.16 and 1.36 stellar radii. Electron-hydrogen atom collisions contribute significantly to the opacity of the layer. The layer has a non-uniform intensity distribution that changes between observing epochs. These results indicate that large-scale surface convective activity strongly influences the dynamics of the inner atmosphere of Betelgeuse, and mass-loss processes.Comment: 13 pages, 5 figures, in press (ApJ

Quantitative Determination of Enhanced and Suppressed Transmission through Subwavelength Slit Arrays in Silver Films

Measurement of the transmitted intensity from a coherent monomode light source through a series of subwavelength slit arrays in Ag films, with varying array pitch and number of slits, demonstrate enhancement (suppression) by as much as a factor of 6 (9) when normalized to that of an isolated slit. Pronounced minima in the transmitted intensity were observed at array pitches corresponding to lambda_SPP, 2lambda_SPP, and 3lambda_SPP where lambda_SPP is the wavelength of the surface plasmon polariton (SPP). Increasing the number of slits to more than four does not increase appreciably the per-slit transmission intensity. These results are consistent with a model for interference between SPPs and the incident wave that fits well the measured transmitted intensity profile.Comment: Figure 4 update

All-optical atom surface traps implemented with one-dimensional planar diffractive microstructures

We characterize the loading, containment and optical properties of all-optical atom traps implemented by diffractive focusing with one-dimensional (1D) microstructures milled on gold films. These on-chip Fresnel lenses with focal lengths of the order of a few hundred microns produce optical-gradient-dipole traps. Cold atoms are loaded from a mirror magneto-optical trap (MMOT) centered a few hundred microns above the gold mirror surface. Details of loading optimization are reported and perspectives for future development of these structures are discussed.Comment: 7 pages, 15 figure

CORPORATIONS-OFFICERS AND DIRECTORS-FIDUCIARY DUTY OF OFFICER PURCHASING STOCK FROM SHAREHOLDER

Defendant, president of a corporation acquired stock owned by plaintiff and others by falsely representing that the corporation had been sold. After enhancing the value of this stock, defendant sold it. Plaintiff brought suit for fraudulent conversion and the trial court directed a verdict for the defendant. On appeal, held, reversed. An officer negotiating with a shareholder for the purchase of shares must act with scrupulous trust and confidence, and unless the officer acts with the utmost fairness the wronged shareholder may invoke the proper remedy. Blazer v. Black, (10th Cir. 1952) 196 F. (2d) 139

Study of high voltage solar array configurations with integrated power control electronics

Solar array electrical configurations for voltage regulatio

Uprooting Children in the Name of Equity

This Article ultimately recommends that courts should reign in, if not abandon, the doctrine of equitable estoppel as it is used in Hague child abduction cases. This Article supports its thesis in four parts. Part I describes the equitable estoppel argument as it has emerged within the Hague Convention framework. Part II then examines the Convention\u27s legislative history and argues that the doctrine is incompatible with that history. Part III analyzes the principle policy basis offered in support of the doctrine: the deterrence of concealment. Part IV focuses on the best way to address concealment within the confines of the Convention structure