Affect of brane thickness on microscopic tidal-charged black holes

We study the phenomenological implications stemming from the dependence of the tidal charge on the brane thickness $L$ for the evaporation and decay of microscopic black holes. In general, the larger $L$, the longer are the black hole life-times and the greater their maximum mass for those cases in which the black hole can grow. In particular, we again find that tidal-charged black holes might live long enough to escape the detectors and even the gravitational field of the Earth, thus resulting in large amounts of missing energy. However, under no circumstances could TeV-scale black holes grow enough to enter the regime of Bondi accretion.Comment: 6 pages, 2 figures, Clarification of tidal charge expression. Additional justification of constraint

Perturbations in the Kerr-Newman Dilatonic Black Hole Background: I. Maxwell waves

In this paper we analyze the perturbations of the Kerr-Newman dilatonic black hole background. For this purpose we perform a double expansion in both the background electric charge and the wave parameters of the relevant quantities in the Newman-Penrose formalism. We then display the gravitational, dilatonic and electromagnetic equations, which reproduce the static solution (at zero order in the wave parameter) and the corresponding wave equations in the Kerr background (at first order in the wave parameter and zero order in the electric charge). At higher orders in the electric charge one encounters corrections to the propagations of waves induced by the presence of a non-vanishing dilaton. An explicit computation is carried out for the electromagnetic waves up to the asymptotic form of the Maxwell field perturbations produced by the interaction with dilatonic waves. A simple physical model is proposed which could make these perturbations relevant to the detection of radiation coming from the region of space near a black hole.Comment: RevTeX, 36 pages in preprint style, 1 figure posted as a separate PS file, submitted to Phys. Rev.

Black Extended Objects, Naked Singularities and P-Branes

We treat the horizons of charged, dilaton black extended objects as quantum mechanical objects. We show that the S matrix for such an object can be written in terms of a p-brane-like action. The requirements of unitarity of the S matrix and positivity of the p-brane tension equivalent severely restrict the number of space-time dimensions and the allowed values of the dilaton parameter a. Generally, black objects transform at the extremal limit into p-branes.Comment: 9 pages, REVTE

Seymour K. Padnos: Family Enterpreneur

Biography of Michigan entrepreneur Seymour K. Padnos. The Seymour and Esther Padnos Hall of Science bears the name of the long-time supporters of Grand Valley.https://scholarworks.gvsu.edu/reports/1016/thumbnail.jp

Injection of liquids into the soil with a high-pressure jet

With regard to injection fertilizing, the more general topic of liquid injection into the soil with the aid of a high-pressure jet is of great importance.  Injection fertilizing means that liquid fertilizer is injected into the soil near the plant roots.  This provides many agronomical advantages.  However, currently available mechanical injection fertilizing techniques in the field use have some disadvantages, such as very heavy wear on individual components.  Therefore, research on the direct, contactless injection of liquids into the soil with the aid of a high-pressure jet is being carried out at the Institute of Agricultural Machinery and Fluid Power of the Technische Universitaet of Braunschweig.  The potential and the possibilities of injection by a high-pressure jet are being examined in trials on a stationary test rig.  In these trials, different soils were used under different conditions (soil moisture, and soil density), and the possibilities of injecting pure water in the form of a high-pressure water jet were studied.  It was shown that the variation of different parameters of the high-pressure jet, such as water pressure, volume flow, etc., allow different injection depths in the soil to be realized.  Especially soil moisture has a very great influence on injection.  In dry soils, for example, the binding forces of the soil bodies (solid body bridges, van-der-Waals forces, etc.) are very strong so that only small injection depths can be reached.  The higher the degree of soil moisture is, the larger the injection depth becomes.  Depending on the soil type, average soil moisture, water pressure of 40 MPa, and speed of the nozzle over the ground of 2 m/s provide injection depths of 70 – 90 mm.  In addition to application in the area of injection fertilizing, the considered injection of liquids into the soil also shows great potential in plant protection, irrigation, as well as the injection of decontamination agents into contaminated soils.Keywords: injection of liquids, soil, fertilisation, high pressure, contactless, frictionles