Extraordinary vacuum black string solutions

In addition to the boosted static solution there are two other classes of stationary string-like solutions of the vacuum Einstein equation in (4+1)-dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.Comment: 20 pages, 4 figures, add 2 reference

Horizon Mass Theorem

A new theorem for black holes is found. It is called the horizon mass theorem. The horizon mass is the mass which cannot escape from the horizon of a black hole. For all black holes: neutral, charged or rotating, the horizon mass is always twice the irreducible mass observed at infinity. Previous theorems on black holes are: 1. the singularity theorem, 2. the area theorem, 3. the uniqueness theorem, 4. the positive energy theorem. The horizon mass theorem is possibly the last general theorem for classical black holes. It is crucial for understanding Hawking radiation and for investigating processes occurring near the horizon.Comment: A new theorem for black holes is establishe

Boosted Top Quark Signals for Heavy Vector Boson Excitations in a Universal Extra Dimension Model

In view of the fact that the $n = 1$ Kaluza-Klein (KK) modes in a model with a Universal Extra Dimension (UED), could mimic supersymmetry signatures at the LHC, it is necessary to look for the $n = 2$ KK modes, which have no analogues in supersymmetry. We discuss the possibility of searching for heavy $n = 2$ vector boson resonances -- especially the $g_2$ -- through their decays to a highly-boosted top quark-antiquark pair using recently-developed top-jet tagging techniques in the hadronic channel. It is shown that $t\bar{t}$ signals from the $n = 2$ gluon resonance are as efficient a discovery mode at the LHC as dilepton channels from the $\gamma_2$ and $Z_2$ resonances.Comment: 22 pages, 8 embedded figure

Current driven magnetization dynamics in helical spin density waves

A mechanism is proposed for manipulating the magnetic state of a helical spin density wave using a current. In this paper, we show that a current through a bulk system with a helical spin density wave induces a spin transfer torque, giving rise to a rotation of the order parameter.The use of spin transfer torque to manipulate the magnetization in bulk systems does not suffer from the obstacles seen for magnetization reversal using interface spin transfer torque in multilayered systems. We demonstrate the effect by a quantitative calculation of the current induced magnetization dynamics of Erbium. Finally we propose a setup for experimental verification.Comment: In the previous version of this paper was a small numerical mistake made when evaluating equation 3 and 9. The number of digits given in the calculation of the torque current tensor is reduced to better represent the accuracy of the calculation. A slightly modified paper have been published in Phys. Rev. Lett. 96, 256601 (2006) 4 pages 3 figure

New biocide active substances:needs and challenges in the EU as viewed by industry

Emerging regulatory initiatives in the EU are driving towards more environmentally safe chemicals, used as such or in a wide range of products and applications. The aim of the regulations is also to foster and support the emergence of new or safer alternatives and to drive innovations thereof. Biocides are chemicals, which are used in a vast and steadily growing number of applications in order to preserve product safety and quality, however, the number of the Active Substances (AS) used in biocides is decreasing in the EU concurrent with the implementation of the Biocidal Product Directive (BPD). Accordingly, the present study attempts to elucidate views of representatives of the biocide industry in order to identify some of the present drivers and challenges of new AS development in the different biocide application areas, with emphasis on the economic feasibility of safer biocide development in the future. Notably, the costs of vertebrate testing are a major factor in development of new AS. Therefore, an evaluation of the costs of such tests and their total proportion of total AS development costs is also discussed. Industry expectations for the implementation of the BPD and impacts thereof are presented.<br

Feasibility of Active Ingredient (AI) development for new biocides in the EU

Biocides usage covers a vast industrial area and the history of biocide and other antimicrobial agent usage in various forms and applications dates back centuries. While the emerging EU regulations (BPD, REACH and others) strive to increase the safety and the eco-efficiency of chemical products and production processes, such changes may also create voids in the availability of current biocides due to outphasing. The present study evaluated the need for new Active Ingredient (AI) development. The feasibility of such development was explored, and the data of economic feasibility analysis shows that, contrary to general expectations, AI development can become profitable within certain economic boundaries

Higher order finite difference schemes for the magnetic induction equations

We describe high order accurate and stable finite difference schemes for the initial-boundary value problem associated with the magnetic induction equations. These equations model the evolution of a magnetic field due to a given velocity field. The finite difference schemes are based on Summation by Parts (SBP) operators for spatial derivatives and a Simultaneous Approximation Term (SAT) technique for imposing boundary conditions. We present various numerical experiments that demonstrate both the stability as well as high order of accuracy of the schemes.Comment: 20 page