Metrology and 1/f noise: linear regressions and confidence intervals in flicker noise context

1/f noise is very common but is difficult to handle in a metrological way. After having recalled the main characteristics of stongly correlated noise, this paper will determine relationships giving confidence intervals over the arithmetic mean and the linear drift parameters. A complete example of processing of an actual measurement sequence affected by 1/f noise will be given

Relentless Assimilationist Indigenous Policy: From Invasion of Group Rights to Genocide in Mercy’s Clothing

Despite the United Nations Declaration of the Rights of Indigenous Peoples, assimilationist policies continue, whether official or effective. Such policies affect more than the right to group choice. The concern is whether indeed genocide or “only” ethnocide (or culturecide)—the elimination of a traditional culture—is at work. Discussions of the distinction between the two terms have been inconsistent enough that at least one commentator has declared that they cannot be used in analytical contexts. While these terms, I contend, have distinct senses, yet in cases of governmental and other institutional assimilationist policy for indigenous peoples, such ethnocide effectively entails genocide. Insofar as any people’s cultural practices and beliefs are essential for life and health, individuals in groups value, if tacitly, their culture as highly as their language or any artifact: Thus, attempts to eradicate a culture through assimilation in fact eradicate individuals’ lives and health and so are effectively murderous. Acknowledgement by worldwide organizations that assimilationist ethnocide is effectively genocide should affect policy concerning indigenous peoples and thus has significance for international law

Shortened horn-reflector antenna

A shortened horn-reflector antenna overcomes the mechanical disadvantages and complexity of the conventional horn-reflector antenna. The shortened antenna offers broadband performance, economic construction, very low antenna temperature, and excellent pattern performance

Optimising the signal-to-noise ratio in measurement of photon pairs with detector arrays

To evidence multimode spatial entanglement of spontaneous down-conversion, detector arrays allow a full field measurement, without any a priori selection of the paired photons. We show by comparing results of the recent literature that electron-multiplying CCD (EMCCD) cameras allow, in the present state of technology, the detection of quantum correlations with the best signal-to-noise ratio (SNR), while intensified CCD (ICCD) cameras allow at best to identify pairs. The SNR appears to be proportional to the square root of the number of coherence cells in each image, or Schmidt number. Then, corrected estimates are derived for extended coherence cells and not very low and not space-stationary photon fluxes. Finally, experimental measurements of the SNR confirm our model

High-frequency capillary waves excited by oscillating microbubbles

This fluid dynamics video shows high-frequency capillary waves excited by the volumetric oscillations of microbubbles near a free surface. The frequency of the capillary waves is controlled by the oscillation frequency of the microbubbles, which are driven by an ultrasound field. Radial capillary waves produced by single bubbles and interference patterns generated by the superposition of capillary waves from multiple bubbles are shown.Comment: This video is an entry for the 2013 Gallery of Fluid Motion. A high-resolution and a low-resolution video are included as ancillary file

Aqueous alteration on main belt primitive asteroids: results from visible spectroscopy

This work focuses on the study of the aqueous alteration process which acted in the main belt and produced hydrated minerals on the altered asteroids. The aqueous alteration is particularly important for unraveling the processes occurring during the earliest times of the Solar System history, as it can give information both on the asteroids thermal evolution and on the localization of water sources in the asteroid belt. We present new spectral observations in the visible region of 80 asteroids belonging to the primitive classes C, G, F, B and P. We combine the present observations with the visible spectra of asteroids available in the literature for a total of 600 primitive main belt asteroids. Our analysis shows that the aqueous alteration sequence starts from the P-type objects, practically unaltered, and increases through the F, B, C, and G asteroids. Around 50% of the observed C-type asteroids show absorption features in the vis. range due to hydrated silicates, implying that more than 70% of them will have a 3 $\mu$m absorption band and thus hydrated minerals on their surfaces. The process dominates in primitive asteroids located between 2.3 and 3.1 AU, that is at smaller heliocentric distances than previously suggested. The aqueous alteration process dominates in the 50--240 km sized primitive asteroids, while it is less effective for bodies smaller than 50 km. No correlation is found between the aqueous alteration process and the asteroids albedo or orbital elements. Comparing the $\sim$ 0.7 $\mu$m band parameters of hydrated silicates and CM2 carbonaceous chondrites, we see that the band center of meteorites is at longer wavelengths than that of asteroids. This difference on center positions may be attributed to different minerals abundances, and to the fact that CM2 available on Earth might not be representative of the whole aqueous altered asteroids population.Comment: Icarus, accepted for publication on 28 January 2014 Manuscript pages: 38; Figures: 13 ; Tables:

Is money useful in the conduct of monetary policy?

Monetary policy ; Money supply

Development concept for a small, split-core, heat-pipe-cooled nuclear reactor

There have been two main deterrents to the development of semiportable nuclear reactors. One is the high development costs; the other is the inability to satisfy with assurance the questions of operational safety. This report shows how a split-core, heat-pipe cooled reactor could conceptually eliminate these deterrents, and examines and summarizes recent work on split-core, heat-pipe reactors. A concept for a small reactor that could be developed at a comparatively low cost is presented. The concept would extend the technology of subcritical radioisotope thermoelectric generators using 238 PuO2 to the evolution of critical space power reactors using 239 PuO2