All sky pointing attitude control system

In a strapped-down gyroscope space vehicle attitude control system, a method and apparatus are provided for gyro drift and input axis misalignment error compensation employing a sun and a star tracker and preselected vehicle calibration maneuvers. The outputs of two-axis strapped-down gyroscopes nominally aligned with the optical axis of the sun and star trackers are measured to provide gyro drift calibration, roll, pitch and yaw axis scale factors and values corresponding to the degree of nonorthogonality between the roll axis and the pitch and yaw gyro input axes and the nonorthogonality of the roll and pitch axes relative to the yaw axis. The vehicle is then rolled and yawed through precomputed angles as modified by the calibrated data stored in a digital computer, and acquires a target without recourse to external references

BEPS Policy Failure—The Case of EU Country-By-Country Reporting1

The tax gap between taxes that are “actually” paid and taxes that “ought” to have been paid by multinational corporate entities has become an area of huge public policy concern in the recent decades. This study reviews the impact of new legislation to reveal the tax gap created by the EU banks and financial institutions passed in 2013 and in particular of the quality of the resulting country-by-country reporting (CBCR) requirement for banks. Although resulting tax gap estimates are noted, they suffer due to significant problems in the published data; much of it is due to the quality of the regulation requiring its publication and implementation. The findings reveal a lack of understanding of the technical and structural weaknesses of accounting in a transnational context in the design of this regulation. CBCR is destined to fail in achieving its regulatory objectives in this context unless necessary reform of the regulation is undertaken

The Biodegradation of Organic Substrates Under Arctic and Subarctic Conditions

The objective of this research was to obtain data on the metabolic reaction rates of the microorganisms indigenous to the cold environments of the arctic and sub-arctic in order to evaluate the natural abilities of the freshwater streams and lakes of Alaska to assimilate the wastes discharged into them. Microorganisms capable of growth even at subzero temperatures have long been known; however, most have consistently fared better at higher temperatures, usually above 20° C. Much of the work done with the biological oxidation of wastes at low temperatures has been with organisms of this type : mesophilic organisms which are able to survive at low temperatures but which are metabolically much more active in the temperature range from 20 to 45° C. Such organisms might be labeled "cold-tolerant," but they are probably biochemically quite different from the truly "cold-loving," or psychrophilic, microorganisms which are able not only to survive but also to thrive at temperatures below 20° C and which, in fact, find temperatures much higher than 25° C intolerable.This work upon which this report (Proj. A-014-ALAS) is based was supported by funds provided by the United States Department of the Interior, Office of Water Resources Research, as authorized under the Water Resources Act of 1964, as amended

3-d resistive MHD simulations of magnetic reconnection and the tearing mode instability in current sheets

Magnetic reconnection plays a critical role in many astrophysical processes where high energy emission is observed, e.g. particle acceleration, relativistic accretion powered outflows, pulsar winds and probably in dissipation of Poynting flux in GRBs. The magnetic field acts as a reservoir of energy and can dissipate its energy to thermal and kinetic energy via the tearing mode instability. We have performed 3d nonlinear MHD simulations of the tearing mode instability in a current sheet. Results from a temporal stability analysis in both the linear regime and weakly nonlinear (Rutherford) regime are compared to the numerical simulations. We observe magnetic island formation, island merging and oscillation once the instability has saturated. The growth in the linear regime is exponential in agreement with linear theory. In the second, Rutherford regime the island width grows linearly with time. We find that thermal energy produced in the current sheet strongly dominates the kinetic energy. Finally preliminary analysis indicates a P(k) 4.8 power law for the power spectral density which suggests that the tearing mode vortices play a role in setting up an energy cascade.Comment: 4 pages, 8 figures, accepted for publication in the International Journal of Modern Physics D, proceedings of HEPRO meeting, held in Dublin, in September 200

A computer-aided telescope pointing system utilizing a video star tracker

The Video Inertial Pointing (VIP) System developed to satisfy the acquisition and pointing requirements of astronomical telescopes is described. A unique feature of the system is the use of a single sensor to provide information for the generation of three axis pointing error signals and for a cathode ray tube (CRT) display of the star field. The pointing error signals are used to update the telescope's gyro stabilization and the CRT display is used by an operator to facilitate target acquisition and to aid in manual positioning of the telescope optical axis. A model of the system using a low light level vidicon built and flown on a balloon-borne infrared telescope is briefly described from a state of the art charge coupled device (CCD) sensor. The advanced system hardware is described and an analysis of the multi-star tracking and three axis error signal generation, along with an analysis and design of the gyro update filter, are presented. Results of a hybrid simulation are described in which the advanced VIP system hardware is driven by a digital simulation of the star field/CCD sensor and an analog simulation of the telescope and gyro stabilization dynamics

The AIROscope pointing and stabilization system

The AIROscope pointing and stabilization system is described. The system is configured with three gimbal axes and rate integrating gyro stabilization to provide a stable platform for infrared astronomy. Error signals for on and off-axis pointing are derived from a video sensor which also drives a ground station display. Other features of the system include direct drive torque motors and electronic suspension damping. Results of analysis and simulations used to design the control loops, and a pointing error analysis are presented

Antioxidants that protect mitochondria reduce interleukin-6 and oxidative stress, improve mitochondrial function, and reduce biochemical markers of organ dysfunction in a rat model of acute sepsis

Funding This study was funded by the Medical Research Council (Grant number G0800149). Research material from this study is not available. Acknowledgement We are very grateful to Dr Robin A.J. Smith, Department of Chemistry, University of Otago, Dunedin, New Zealand, for the generous gifts of MitoE and MitoQ, without which this work would not have been possible.Peer reviewedPublisher PD

Development and Application of Operational Techniques for the Inventory and Monitoring of Resources and Uses for the Texas Coastal Zone

There are no author-identified significant results in this report