Asymptotic behavior of a scalar field with an arbitrary potential trapped on a Randall-Sundrum’s braneworld: the effect of a negative dark radiation term on a Bianchi I brane

In this work we present a phase space analysis of a quintessence field and a perfect fluid trapped in a Randall-Sundrum’s Braneworld of type 2. We consider a homogeneous but anisotropic Bianchi I brane geometry. Moreover, we consider the effect of the projection of the five-dimensional Weyl tensor onto the three-brane in the form of a negative Dark Radiation term. For the treatment of the potential we use the “Method of f-devisers” that allows investigating arbitrary potentials in a phase space. We present general conditions on the potential in order to obtain the stability of standard 4D and non-standard 5D de Sitter solutions, and we provide the stability conditions for both scalar field-matter scaling solutions, scalar field-dark radiation solutions and scalar field-dominated solutions. We find that the shear-dominated solutions are unstable (particularly, contracting shear-dominated solutions are of saddle type). As a main difference with our previous work, the traditionally ever-expanding models could potentially re-collapse due to the negativity of the dark radiation. Additionally, our system admits a large class of static solutions that are of saddle type. These kinds of solutions are important at intermediate stages in the evolution of the universe, since they allow the transition from contracting to expanding models and viceversa. New features of our scenario are the existence of a bounce and a turnaround, which lead to cyclic behavior, that are not allowed in Bianchi I branes with positive dark radiation term. Finally, as specific examples we consider the potentials V∝sinh^?α (β?) and V∝[cosh(ξ?)?1] which have simple f-devisers.     

Economics of the Kyoto Protocol for Russia

Abstract

In this article we propose a careful analysis of the economic consequences of the Kyoto Protocol for Russia, taking into account the most recently available data and the latest developments in the trends regarding Russian economic recovery. We present a review of different GHG forecasts for Russia and develop a new forecast for uncertain GDP growth and changing elasticity of GHG emission per GDP. Since the rate of growth remains uncertain, elasticity could change over time, as well as the fuel mix. We apply the Monte-Carlo method to simulate these uncertainties and to produce a reasonable interval for CO₂ emissions in 2010. The probability of Russia exceeding its Kyoto emissions budget is essentially zero. Further, we discuss the benefits for Russia from the Kyoto Protocol, and more generally from implementation of GHG mitigation policy. Ancillary benefits from Kyoto Protocol implementation will bring essential reductions in risk to human health. On the other hand, potential negative changes in the fuel mix and GDP structure, as well as a slowing of the innovation process, could exacerbate existing health problems. Alternatives to the Kyoto Protocol may bring much tougher commitments to Russia. We conclude that the Kyoto Protocol is the best possible deal for Russia. Therefore, Russia most will ratify it.     

The Hinode (Solar-B) Mission: An Overview

The Hinode satellite (formerly Solar-B) of the Japan Aerospace Exploration Agency’s Institute of Space and Astronautical Science (ISAS/JAXA) was successfully launched in September 2006. As the successor to the Yohkoh mission, it aims to understand how magnetic energy gets transferred from the photosphere to the upper atmosphere and results in explosive energy releases. Hinode is an observatory style mission, with all the instruments being designed and built to work together to address the science aims. There are three instruments onboard: the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer (EIS), and the X-Ray Telescope (XRT). This paper provides an overview of the mission, detailing the satellite, the scientific payload, and operations. It will conclude with discussions on how the international science community can participate in the analysis of the mission data. T. Kosugi deceased 26 November 2006.     

The Magnetic Structure of a Coronal X-Ray Bright Point

X-ray bright points are small dynamic loop structures that are observed all over the solar corona. The high spatial and temporal resolution of the TRACE instrument allows bright points to be studied in much greater detail than previously possible. This paper focuses on a specific bright point which occurred for about 20 hours on 13–14 June 1998 and examines its dynamic structure in detail. This example suggests that the mechanisms that cause bright points to form and evolve are more complex than previously thought. In this case, reconnection probably plays a major part during the formation and brightening of the loop structure. However, later on the foot points rotate injecting twist into the bright point which may cause an instability to occur with dynamic results. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1017907406350     

New advances in methodology for statistical tests useful in geostatistical studies

Methodology for statistical procedures to perform tests of hypothesis pertaining to various aspects of geostatistical investigations has been slow in developing. The correlated nature of the data precludes most classical tests and makes the design of new tests difficult. Recent studies have led to modifications of the classical t test which allow for the intercorrelation. In addition, results for certain nonparametric tests have been obtained. The conclusions of these studies provide a variety of new tools for the geostatistician in deciding questions on significant differences and magnitudes.This paper was presented at MGUS 87 Conference, Redwood City, California, 14 April 1987.     

The warped gas and dust lane in NGC 3718

We present the first observations of molecular line emission in NGC 3718 with the IRAM 30m and the Plateau de Bure Interferometer. This galaxy is an excellent example for a strongly warped gas disk harboring an active galactic nucleus (AGN). An impressive dust lane is crossing the nucleus and a warp is developing into a polar ring. The molecular gas content is found to be typical of an elliptical galaxy with a relatively low molecular gas mass content (∼ 4 × 10⁸ M _⊙). The molecular gas distribution is found to warp from the inner disk together with the HI distribution. The CO data were also used to improve the kinematic modeling in the inner part of the galaxy, based on the so-called tilted ring-model. The nature of NGC 3718 is compared with its northern sky `twin' Centaurus A and the possible recent swallowing of a small-size gas-rich spiral is discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Bidirectional seismic performance of steel beam to circular tubular column connections with outer diaphragm

This paper presents an experimental investigation on the seismic behavior of H‐beam to circular tubular column connections stiffened by an outer ring diaphragm. An innovative three‐dimensional (3D) connection subassembly testing system was first described. Specimens representative of two‐dimensional (2D) interior columns, 3D interior and exterior columns in a steel building frame were then tested to failure under unidirectional or bidirectional cyclic loads. Various specimen parameters are used to evaluate their effects on connection behavior. Test results indicate significantly different failure modes for 2D and 3D weak panel connections, with panel shear buckling and local distortion of outer diaphragm occurring only for 3D connections. The weak beam connections unexceptionally exhibited final fracture at the junction between diaphragm and beam flange. In contrast with weak beam connections, weak panel connections demonstrated better seismic performance and ductility. As a result, a seismic design philosophy considering panel zone yielding before beam flexural yielding is proposed. Based on experiment observations, small diaphragm width and simplified fillet welding are found to be feasible especially for weak beam connections, improving architectural appearance and facilitating construction. Strength evaluations also suggest that current AIJ design provisions may be appropriate when applied to panel zones in 3D connections. Copyright © 2010 John Wiley & Sons, Ltd.     

Comparison of age distributions estimated from environmental tracers by using binary-dilution and numerical models of fractured and folded karst: Shenandoah Valley of Virginia and West Virginia, USA

Measured concentrations of environmental tracers in spring discharge from a karst aquifer in the Shenandoah Valley, USA, were used to refine a numerical groundwater flow model. The karst aquifer is folded and faulted carbonate bedrock dominated by diffuse flow along fractures. The numerical model represented bedrock structure and discrete features (fault zones and springs). Concentrations of ³H, ³He, ⁴He, and CFC-113 in spring discharge were interpreted as binary dilutions of young (0–8  years) water and old (tracer-free) water. Simulated mixtures of groundwater are derived from young water flowing along shallow paths, with the addition of old water flowing along deeper paths through the model domain that discharge to springs along fault zones. The simulated median age of young water discharged from springs (5.7  years) is slightly older than the median age estimated from ³H/³He data (4.4  years). The numerical model predicted a fraction of old water in spring discharge (0.07) that was half that determined by the binary-dilution model using the ³H/³He apparent age and ³H and CFC-113 data (0.14). This difference suggests that faults and lineaments are more numerous or extensive than those mapped and included in the numerical model.     

Field relationship of high-grade Neo- to Mesoarchaean rocks of South-East Greenland: Tectonometamorphic and magmatic evolution

South-East Greenland forms part of the North Atlantic Craton and is characterized by migmatitic orthogneisses, narrow bands of mafic granulite, ultramafic and possible meta-sedimentary rocks, and alkaline-carbonatitic intrusive rocks. Mafic granulite, meta-sedimentary and ultramafic rocks form the basement for the emplacement of granitic intrusions at ca. 2865 Ma that lasted episodically until ca. 2790 Ma and continuously during 2750–2700 Ma. The area is structurally complex with evidence of at least seven deformation events including reclined and mushroom-like fold interference patterns. An older (> 2790 Ma) foliation formed in granitic rocks and the basement during the Timmiarmiut Orogeny (D_T). Deformation associated with the ca. 2790–2700 Ma Skjoldungen Orogeny folded this early foliation, and is associated with a penetrative foliation that is refolded progressively in a northeast–southwest oriented stress field. The orientation of the stress field progressively rotated into a northnorthwest–southsoutheast orientation during the last stages of the orogeny. The orogeny is also characterized by syn-deformational anatexis at granulite-facies (at approximately 800 °C and 5–8 kbar, ca. 2790–2740 Ma), which decreased to the amphibolite-facies at ca. 2730 Ma.The late- to post-tectonic granite and alkaline rocks assigned to the Skjoldungen Alkaline Province intruded the central-northern part around 2710 Ma. This was followed by north–south extensional deformation during the Singertat Stage forming discrete shear-zones at greenschist-facies grades, which is coeval with the emplacement of pegmatite, ijolite, and carbonatite emplacement during ca. 2680–2650 Ma.Similar lithology and tectonic processes in the Tasiusarsuaq Terrane of southern West Greenland and the Lewisian Complex in Scotland suggest a possibly large Archaean terrane at that time, which, taking the present size, at least covered around 500–600 km in an east–west direction and approximately 200 km in a north–south direction.