Effect of Finite Larmor Radius on the Cosmic Ray Penetration into an Interplanetary Magnetic Flux Rope

We discuss a mechanism for cosmic ray penetration into an interplanetary magnetic flux rope, particularly the effect of the finite Larmor radius and magnetic field irregularities. First, we derive analytical solutions for cosmic ray behavior inside a magnetic flux rope, on the basis of the Newton-Lorentz equation of a particle, to investigate how cosmic rays penetrate magnetic flux ropes under an assumption of there being no scattering by small-scale magnetic field irregularities. Next, we perform a numerical simulation of a cosmic ray penetration into an interplanetary magnetic flux rope by adding small-scale magnetic field irregularities. This simulation shows that a cosmic ray density distribution is greatly different from that deduced from a guiding center approximation because of the effect of the finite Larmor radius and magnetic field irregularities for the case of a moderate to large Larmor radius compared to the flux rope radius.Comment: 17 pages, 14 figures, accepted for publication in The Astrophysical Journa

‘Gold, guns & goons’: the complexity of electoral irregularities in Nigeria, 1999-2007

Electoral irregularities have become an irritant but inseparable aspect of democratic development in several countries of the world. From the US Florida electoral crisis of 2000 to the Orange Revolution in Ukraine in 2004/2005, which was staged to protest perceived electoral malpractice, the story has been that of the inability of electoral bodies to conduct free and fair elections devoid of electoral malpractice, coupled with incompetence and numerous electoral flaws, unfairness and injustice. Although, Nigeria’s case of electoral irregularities may not be unique, their magnitude makes it a good subject of historical investigations. This work examines the impact of the illegal use of money, weapons and thugs as aspects of electoral irregularities in the conduct of elections in Nigeria between 1999 and 2007

Phase perturbation measurements through a heated ionosphere

High frequency radiowaves incident on an overdense (i.e., HF-frequency penetration frequency) ionosphere produce electron density irregularities. The effect of such ionospheric irregularities on the phase of UHF-radiowaves was determined. For that purpose the phase of radiowaves originating from celestial radio sources was observed with two antennas. The radiosources were chosen such that the line of sight to at least one of the antennas (usually both) passed through the modified volume of the ionosphere. Observations at 430 MHz and at 2380 MHz indicate that natural irregularities have a much stronger effect on the UHF phase fluctuations than the HF-induced irregularities for presently achieved HF-power densities of 20-80 uW/sq m. It is not clear whether some of the effects observed are the result of HF-modification of the ionosphere. Upper limits on the phase perturbations produced by HF-modification are 10 deg at 2380 MHz and 80 deg at 430 MHz

Heat flow in variable polarity plasma arc welds

The space shuttle external tank and the space station Freedom are fabricated by the variable polarity plasma arc (VPPA) welding. Heat sink effects (taper) are observed when there are irregularities in the work-piece configuration especially if these irregularities are close to the weld bead. These heat sinks affect the geometry of the weld bead, and in extreme cases they could cause defects such as incomplete fusion. Also, different fixtures seem to have varying heat sink effects. The objective of the previous, present, and consecutive research studies is to investigate the effect of irregularities in the work-piece configuration and fixture differences on the weld bead geometry with the ultimate objective to compensate automatically for the heat sink effects and achieve a perfect weld

Haiti's Fatally Flawed Elections

This report describes the results of an independent recount of vote tally sheets from Haiti's November 28 presidential election. These 11,181 election tally sheets from across Haiti were posted online by Haiti's Provisional Electoral Council (CEP). It finds that for some 1,326 voting booths, or 11.9 percent of the total, tally sheets were either never received by the CEP or were quarantined for irregularities. This corresponds to about 12.7 percent of the vote, which was not counted and is not included in the final totals that were released by the CEP on December 7, 2010 and reported by the press. It also found many more tally sheets that had irregularities in the vote totals that were sufficient to disqualify them, and a large number of clerical errors that further undermines the credibility of the vote count. The report finds that based on the numbers of irregularities, it is impossible to determine who should advance to a second round. If there is a second round, it will be based on arbitrary assumptions and/or exclusions