Birth, survival and death of languages by Monte Carlo simulation

Simulations of physicists for the competition between adult languages since 2003 are reviewed. How many languages are spoken by how many people? How many languages are contained in various language families? How do language similarities decay with geographical distance, and what effects do natural boundaries have? New simulations of bilinguality are given in an appendix.Comment: 24 pages review, draft for Comm.Comput.Phys., plus appendix on bilingualit

A Long-Lived Accretion Disk Around a Lithium-Depleted Binary T Tauri Star

We present a high dispersion optical spectrum of St 34 and identify the system as a spectroscopic binary with components of similar luminosity and temperature (both M3+/-0.5). Based on kinematics, signatures of accretion, and location on an H-R diagram, we conclude that St 34 is a classical T Tauri star belonging to the Taurus-Auriga T Association. Surprisingly, however, neither component of the binary shows LiI 6708 A, absorption, the most universally accepted criterion for establishing stellar youth. In this uniquely known instance, the accretion disk appears to have survived longer than the lithium depletion timescale. We speculate that the long-lived accretion disk is a consequence of the sub-AU separation companion tidally inhibiting, though not preventing, circumstellar accretion. Comparisons with pre-main sequence evolutionary models imply, for each component of St 34, a mass of 0.37+/-0.08 Msun and an isochronal age of 8+/-3 Myr, which is much younger than the predicted lithium depletion timescale of ~ 25 Myr. Although a distance 38% closer than that of Taurus-Auriga or a hotter temperature scale could reconcile this discrepancy at 21-25 Myr, similar discrepancies in other systems and the implications of an extremely old accreting Taurus-Auriga member suggest instead a possible problem with evolutionary models. Regardless, the older age implied by St 34's depleted lithium abundance is the first compelling evidence for a substantial age spread in this region. Additionally, since St 34's coeval co-members with early M spectral types would likewise fail the lithium test for youth, current membership lists may be incomplete.Comment: 4 pages, including 2 figures. Accepted for publication in ApJ Let

Disorder induced Coulomb gaps in graphene constrictions with different aspect ratios

We present electron transport measurements on lithographically defined and etched graphene nanoconstrictions with different aspect ratios including different lengths (L) and widths (W). A roughly length-independent disorder induced effective energy gap can be observed around the charge neutrality point. This energy gap scales inversely with the width even in regimes where the length of the constriction is smaller than its width (L<W). In very short constrictions, we observe both resonances due to localized states or charged islands and an elevated overall conductance level (0.1-1e2/h), which is strongly length-dependent in the gap region. This makes very short graphene constrictions interesting for highly transparent graphene tunneling barriers.Comment: 4 pages, 4 figure

Players, Owners, and Contracts in the NFL: Why the Self-Help Specific Performance Remedy Cannot Escape the Clean Hands Doctrine

Is it fair that professional football players possess so much control in renegotiating contracts? Do the players in fact possess the control that we perceive them to have? Often, players do have most of the bargaining power, as in the case of college players being chosen in the draft. Once a team has chosen to pursue a draftee out of college, no other team has the right to interfere with that process. If that club fails to sign the player, the club wastes a valuable pick, and there is no remedy for such a failure. But after that introduction into the league, who retains control? It appears that the player still retains control because, although the player is under contract, he can withhold playing for the club until it accedes to his new demands. Although those with promanagement sentiment might agree that this option should be available to the club, the remedy will not be accepted by the courts because the clean hands doctrine poses a major roadblock to the legal implementation of the self-help specific performance remedy. Before analyzing the problems that the self-help specific performance remedy faces, this Comment begins in Section I by describing the self-help specific performance remedy as applied to professional athletes. Section II then explains the clean hands doctrine and the rationales behind it. Section III continues by explaining why the self-help specific performance remedy should not be exempt from the defense of the clean hands doctrine. Section IV then concludes that the clean hands doctrine is a proper defense and will defeat any attempt to implement the self-help specific performance remedy

Players, Owners, and Contracts in the NFL: Why the Self-Help Specific Performance Remedy Cannot Escape the Clean Hands Doctrine

Is it fair that professional football players possess so much control in renegotiating contracts? Do the players in fact possess the control that we perceive them to have? Often, players do have most of the bargaining power, as in the case of college players being chosen in the draft. Once a team has chosen to pursue a draftee out of college, no other team has the right to interfere with that process. If that club fails to sign the player, the club wastes a valuable pick, and there is no remedy for such a failure. But after that introduction into the league, who retains control? It appears that the player still retains control because, although the player is under contract, he can withhold playing for the club until it accedes to his new demands. Although those with promanagement sentiment might agree that this option should be available to the club, the remedy will not be accepted by the courts because the clean hands doctrine poses a major roadblock to the legal implementation of the self-help specific performance remedy. Before analyzing the problems that the self-help specific performance remedy faces, this Comment begins in Section I by describing the self-help specific performance remedy as applied to professional athletes. Section II then explains the clean hands doctrine and the rationales behind it. Section III continues by explaining why the self-help specific performance remedy should not be exempt from the defense of the clean hands doctrine. Section IV then concludes that the clean hands doctrine is a proper defense and will defeat any attempt to implement the self-help specific performance remedy

SMC Message Browser Projects

I work directly with the System Monitoring and Control (SMC) software engineers who develop, test and release custom and commercial software in support of the Kennedy Space Center Spaceport Command and Control System. (SCCS). SMC uses Commercial Off-The-Shelf (COTS) Enterprise Management Systems (EMS) software which provides a centralized subsystem for configuring, monitoring, and controlling SCCS hardware and software used in the Control Rooms. There are multiple projects being worked on using the COTS EMS software. I am currently working with the HP Operations Manager for UNIX (OMU) software which allows Master Console Operators (MCO) to access, view and interpret messages regarding the status of the SCCS hardware and software. The OMU message browser gets cluttered with messages which can make it difficult for the MCO to manage. My main project involves determining ways to reduce the number of messages being displayed in the OMU message browser. I plan to accomplish this task in two different ways: (1) by correlating multiple messages into one single message being displayed and (2) to create policies that will determine the significance of each message and whether or not it needs to be displayed to the MCO. The core idea is to lessen the number of messages being sent to the OMU message browser so the MCO can more effectively use it

Transport in coupled graphene-nanotube quantum devices

We report on the fabrication and characterization of all-carbon hybrid quantum devices based on graphene and single-walled carbon nanotubes. We discuss both, carbon nanotube quantum dot devices with graphene charge detectors and nanotube quantum dots with graphene leads. The devices are fabricated by chemical vapor deposition growth of carbon nanotubes and subsequent structuring of mechanically exfoliated graphene. We study the detection of individual charging events in the carbon nanotube quantum dot by a nearby graphene nanoribbon and show that they lead to changes of up to 20% of the conductance maxima in the graphene nanoribbon acting as a good performing charge detector. Moreover, we discuss an electrically coupled graphene-nanotube junction, which exhibits a tunneling barrier with tunneling rates in the low GHz regime. This allows to observe Coulomb blockade on a carbon nanotube quantum dot with graphene source and drain leads

Computer-Simulation des Wettbewerbs zwischen Sprachen

Recent computer simulations of the competition between thousands of languages are reviewed, and some new results on language families and language similarities are presented.Comment: 16 pages including all figures; in GERMAN language, more results than first versio