Power Supply Options for a Naval Railgun

Large railguns require powerful power supply units. At the French-German Research Institute of Saint-Louis (ISL) most experimental railguns are driven by power supply units based on capacitors. Recent investigations at ISL explore the possibility to use coil based systems to increase the energy density of the power supply. In this study an electrical circuit simulation is used to investigate the difference for railgun operation in between a capacitor and a coil based power supply with respect to current amplitude behavior and projectile velocity. For this a scenario of a 25 MJ muzzle energy railgun is simulated with two different power supply options, replacing capacitors by coils and using a range of circuit resistances. The resistance determines to a large part the losses of the system and defines therefore the efficiency of the launch and the size of the power supply. The interpretation of the results of the performed simulations leads to the conclusion that the capacitor based system "naturally" pro- duces a favorable current pulse trace with respect to launching a mechanical delicate payload. Further simulations show that the disadvantage of the inductor based supply can be mitigated by increasing the power supply unit subdivision into smaller units.Comment: Submitted to IEEE Transactions on Plasma Physic

Experiments to increase the used Energy with the PEGASUS Railgun

The French-German Research Institute (ISL) has several railguns installed, the largest of these is the PEGASUS accelerator. It is a 6m long, 4x4 cm2 caliber distributed energy supply (DES) railgun. It has a 10 MJ capacitor bank as energy supply attached to it. In the past, this installation was used to accelerate projectiles with a mass of about 300 g to velocities up to 2500 m/s. In the ongoing investigation, it is attempted to accelerate heavier projectiles to velocities above 2000m/s. For this a new type of projectile including a payload section was developed. In this paper the results of the experiments with payload projectiles using a primary energy between 3.8 MJ and 4.8 MJ are discussed.Comment: 6 pages, 11 figures, Submitted to IEEE Transactions on Plasma Science, Special Issue -- Pulsed Power Science & Technology 201

A Scenario for a Future European Shipboard Railgun

Railguns can convert large quantities of electrical energy into kinetic energy of the projectile. This was demon- strated by the 33 MJ muzzle energy shot performed in 2010 in the framework of the Office of Naval Research (ONR) electromag- netic railgun program. Since then, railguns are a prime candidate for future long range artillery systems. In this scenario, a heavy projectile (several kilograms) is accelerated to approx. 2.5 km/s muzzle velocity. While the primary interest for such a hypersonic projectile is the bombardment of targets being hundreds of kilometers away, they can also be used to counter airplane attacks or in other direct fire scenarios. In these cases, the large initial velocity significantly reduces the time to impact the target. In this study we investigate a scenario, where a future shipboard railgun installation delivers the same kinetic energy to a target as the explosive round of a contemporary European ship artillery system. At the same time the railgun outperforms the current artillery systems in range. For this scenario a first draft for the parameters of a railgun system were derived. For the flight-path of the projectile, trajectories for different launch angles were simulated and the aero-thermodynamic heating was estimated using engineering-tools developed within the German Aerospace Center (DLR). This enables the assessment of the feasibility of the different strike scenarios, as well as the identification of the limits of the technology. It is envisioned that this baseline design can be used as a helpful starting point for discussions of a possible electrical weaponization of future European warships.Comment: Submitted to IEEE Transactions on Plasma Physics, Special Issue EML 201

IP Management – Key Skills in a Knowledge Economy

Intellectual property (IP) is an important element in the knowledge economy. Through focused appropriation strategies, companies can use intellectual property to generate profits from the investments they make in new knowledge. To do so, it is necessary for various subsystems of the knowledge economy to be combined at an interdisciplinary level. To support the success of the company, IP management can help to optimize appropriation mechanisms. A consideration of the economic properties of intangible assets and an interdisciplinary background of those involved are required for this. With the management of IP, new competences and skills are entering the knowledge economy. By understanding the generation of wealth in the knowledge economy and the IP exploitation mechanisms, the need for new training approaches becomes clear

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Simulation und Analyse von Myonenereignissen im AMANDA-B4-Neutrinoteleskop

im Postscript-Forma

AMANDA-B10 Limit on UHE Muon-Neutrinos

Abstract Data taken in 1997 with the AMANDA-B10 detector is searched for muonneutrinos with energies above 10 16 eV. At these energies the earth is opaque to neutrinos and neutrino induced events are concentrated at the horizon. The background are large muon bundles from downgoing atmospheric air shower events. In this search no excess events above background has been observed and a preliminary 90 % C.L. upper limit to an assumed E −2 muon-neutrino flux at the detector of E 2 Φ(2.5 · 10 15 eV &lt; E ν &lt; 5.6 · 10 18 eV) = 7.2 · 10 −7 cm −2 s −1 sr −1 GeV has been set. This is currently the most restrictive experimental bound placed by any neutrino detector at these energies