Investigation of weld joint detection capabilities of a coaxial weld vision system

This report describes the second phase of a series of evaluations of a vision-based welding control sensor for the Space shuttle Main Engine Robotic Welding System. The robotic welding system is presently under development at the Marshall Space Flight Center. This evaluation determines the factors influencing the minimum joint gap required for consistent detection of the weld joint

Seam tracking performance of a Coaxial Weld Vision System and pulsed welding

This report describes a continuation of a series of tests on the Coaxial Weld Vision System at MSFC. The ability of the system to compensate for transients associated with pulsed current welding is analyzed. Using the standard image processing approach for root pass seam tracking, the system is also tested for the ability to track the toe of a previous weld bead, for tracking multiple pass weld joints. This Coaxial Weld Vision System was developed by the Ohio State University (OSU) Center for Welding Research and is a part of the Space Shuttle Main Engine Robotic Welding Development System at MSFC

Density fluctuations and the structure of a nonuniform hard sphere fluid

We derive an exact equation for density changes induced by a general external field that corrects the hydrostatic approximation where the local value of the field is adsorbed into a modified chemical potential. Using linear response theory to relate density changes self-consistently in different regions of space, we arrive at an integral equation for a hard sphere fluid that is exact in the limit of a slowly varying field or at low density and reduces to the accurate Percus-Yevick equation for a hard core field. This and related equations give accurate results for a wide variety of fields

Investigation of the D and E region during the IQSY Final report, 1964 - 1965

Nike-Apache rocket measurements of lower ionosphere during International Quiet Sun Yea

A. C. Power Losses in MOV Surge Arrestors

It was the objective of this study to measure power losses occurring in MOV surge arrestors as they were subjected to various voltage Excitations. In particular, power losses were observed in two MOV devices as sinusoidal voltages of different magnitudes were applied, at various frequencies in the range of typical power frequencies and common harmonics. Power losses were also observed in an MOV device for applied voltages consisting of the sum of 60 Hertz sinusoids and a single harmonic. The measurement procedure consisted of obtaining digital records representing the waveforms of voltage across and current through the MOV device during operation; power was calculated as the mean of the product of these digitally represented waveforms; This report contains a detailed description of the implementation of this procedure, as well as a discussion of some of its limitations when making measurements on highly reactive devices. Experimental results indicate that power losses in the MOV devices studied were primarily dependent upon frequency of operation, and peak amplitude of applied voltage. The results indicate that 60 Hertz specifications given for a particular device do not, in general, apply for other frequencies or non-sinusoidal excitation

Restructure and Reform: Products-Liability Law in North Carolina

This Article suggests that, although previous revisions to the North Carolina Products Liability Act brought progress, more revisions are needed, and these revisions will be best accomplished by incorporating additional measures into the act, especially those that have gained wide acceptance elsewhere. Part I of this Article provides a brief introduction to the early development of products liability law. Part I.A discusses tort-law influences in products liability, and Part I.B focuses on contributions from contract law. Parts II.A and II.B briefly describe MUPLA and the Restatement (Third) of Torts: Products Liability, respectively. Part III discusses the current state of products-liability law in North Carolina and suggests a number of proposed improvements to North Carolina’s products-liability act

Accounts Receivable Factoring As A Response To Weak Governance: Panel Data Evidence

Accounts receivable factoring is a financing arrangement that occurs when a business sells its accounts receivables.  Factoring has emerged as the most important source of working capital for small and medium sized enterprises (SMEs) in many economies because weak laws, poor enforcement, and the associated informational opacity put the SMEs at a disadvantage when borrowing.  This paper presents an empirical analysis of cross-country differences in factoring activity to determine whether the quality of governance is a significant determinant of the level of factoring activity.  Our analysis is based on a reduced form model that relates a country’s factoring activity (turnover) to the quality of governance, while controlling for other determinants of factoring discussed in the literature.  We use data for a panel of 59 countries, over the period 1995 – 2005.  Our findings support the hypothesis that factoring is more prevalent in economies with weak governance.  Additionally, we present evidence that factor turnover is decreasing in the incidence of corruption

Circles in the Sky: Finding Topology with the Microwave Background Radiation

If the universe is finite and smaller than the distance to the surface of last scatter, then the signature of the topology of the universe is writ large on the microwave background sky. We show that the microwave background will be identified at the intersections of the surface of last scattering as seen by different ``copies'' of the observer. Since the surface of last scattering is a two-sphere, these intersections will be circles, regardless of the background geometry or topology. We therefore propose a statistic that is sensitive to all small, locally homogeneous topologies. Here, small means that the distance to the surface of last scatter is smaller than the ``topology scale'' of the universe.Comment: 14 pages, 10 figures, IOP format. This paper is a direct descendant of gr-qc/9602039. To appear in a special proceedings issue of Class. Quant. Grav. covering the Cleveland Topology & Cosmology Worksho

Description of the fluctuating colloid-polymer interface

To describe the full spectrum of surface fluctuations of the interface between phase-separated colloid-polymer mixtures from low scattering vector q (classical capillary wave theory) to high q (bulk-like fluctuations), one must take account of the interface's bending rigidity. We find that the bending rigidity is negative and that on approach to the critical point it vanishes proportionally to the interfacial tension. Both features are in agreement with Monte Carlo simulations.Comment: 5 pages, 3 figures, 1 table. Accepted for publication in Phys. Rev. Let

Design of a Hypersonic Waterjet Apparatus Driven by High Explosives

The design and construction of a hypersonic waterjet apparatus is described. Jet velocities from 0.5 to 5 km/s have been achieved using a high explosive charge. Images are obtained in situ on various target substrates using a high-speed framing camera. Experimental results are shown for the impact of high velocity waterjets on propellants and high explosive samples. By observing the impact of the waterjet at a wide range of velocities a safety threshold can be determined where no reaction takes place