The JPL isolated application experiment series

A set of small (approximately 60-150 kWe) solar thermal power experiments, each of which is meant to address a separate isolated load application, will employ point focusing distributed receiver technology with emphasis on electric and possibly some thermal power applications. The program will be closely integrated with the technology development element of the thermal power systems project with the objective of utilizing the technologies being developed under that program

Dynamics of Black Hole Pairs II: Spherical Orbits and the Homoclinic Limit of Zoom-Whirliness

Spinning black hole pairs exhibit a range of complicated dynamical behaviors. An interest in eccentric and zoom-whirl orbits has ironically inspired the focus of this paper: the constant radius orbits. When black hole spins are misaligned, the constant radius orbits are not circles but rather lie on the surface of a sphere and have acquired the name "spherical orbits". The spherical orbits are significant as they energetically frame the distribution of all orbits. In addition, each unstable spherical orbit is asymptotically approached by an orbit that whirls an infinite number of times, known as a homoclinic orbit. A homoclinic trajectory is an infinite whirl limit of the zoom-whirl spectrum and has a further significance as the separatrix between inspiral and plunge for eccentric orbits. We work in the context of two spinning black holes of comparable mass as described in the 3PN Hamiltonian with spin-orbit coupling included. As such, the results could provide a testing ground of the accuracy of the PN expansion. Further, the spherical orbits could provide useful initial data for numerical relativity. Finally, we comment that the spinning black hole pairs should give way to chaos around the homoclinic orbit when spin-spin coupling is incorporated.Comment: 16 pages, several figure

The Debt Limit: History and Recent Increases

[Excerpt] The statutory debt limit applies to almost all federal debt. The limit applies to federal debt held by the public (that is, debt held outside the federal government itself) and to federal debt held by the government’s own accounts. Federal trust funds, such as Social Security, Medicare, Transportation, and Civil Service Retirement accounts, hold most of this internally held debt. The government’s surpluses or deficits determine essentially all of the change in debt held by the public. The government’s on-budget fiscal balance, which excludes a U.S. Postal Service net surplus or deficit and a large Social Security surplus of payroll taxes net of paid benefits, does not directly affect debt held in government accounts. Increases or decreases in debt held by government accounts result from net financial flows into accounts holding the debt, such as the Social Security Trust Fund. Legal requirements and government accounting practices also affect levels of debt held by government accounts. On August 2, 2011, President Obama signed into law the Budget Control Act of 2011 (BCA; S.365), after an extended debt limit episode. The federal debt reached its statutory limit on May 16, 2011, prompting Treasury Secretary Timothy Geithner to declare a debt issuance suspension period, allowing certain extraordinary measures to extend Treasury’s borrowing capacity. The BCA included provisions aimed at deficit reduction and would allow the debt limit to rise between $2,100 billion and$2,400 billion in three stages, with the latter two subject to congressional disapproval. Two of the three increases, totaling $900 billion, have occurred, and a request for a third increase is likely to occur in mid-January 2012

A 6-INCH SUBSONIC HIGH-TEMPERATURE ARC TUNNEL FOR STRUCTURES AND MATERIAL TESTS

Subsonic high temperature arc heated wind tunnel tests for structural material

Distinguishing Marks of Simply-connected Universes

A statistical quantity suitable for distinguishing simply-connected Robertson-Walker (RW) universes is introduced, and its explicit expressions for the three possible classes of simply-connected RW universes with an uniform distribution of matter are determined. Graphs of the distinguishing mark for each class of RW universes are presented and analyzed.There sprout from our results an improvement on the procedure to extract the topological signature of multiply-connected RW universes, and a refined understanding of that topological signature of these universes studied in previous works.Comment: 13 pages, 4 figures, LaTeX2e. To appear in Int. J. Mod. Phys. D (2000

Ground state structure and interactions between dimeric 2D Wigner crystals

We study the ground state ordering and interactions between two two-dimensional Wigner crystals on neutralizing charged plates by means of computer simulation. We consider crystals formed by (i) point-like charges and (ii) charged dimers, which mimic the screening of charged surfaces by elongated multivalent ions such as aspherical globular proteins, charged dendrimers or short stiff polyelectrolytes. Both systems, with point-like and dimeric ions, display five distinct crystalline phases on increasing the interlayer distance. In addition to alteration of translational ordering within the bilayer, the phase transitions in the dimeric system are characterized by alteration of orientational ordering of the ions.Comment: Revised versio

Kinetic Inflation in Stringy and Other Cosmologies

An inflationary epoch driven by the kinetic energy density in a dynamical Planck mass is studied. In the conformally related Einstein frame it is easiest to see the demands of successful inflation cannot be satisfied by kinetic inflation alone. Viewed in the original Jordan-Brans-Dicke frame, the obstacle is manifest as a kind of graceful exit problem and/or a kind of flatness problem. These arguments indicate the weakness of only the simplest formulation. {}From them can be gleaned directions toward successful kinetic inflation.Comment: 26 pages, LaTeX, CITA-94-2

Message and time efficient multi-broadcast schemes

We consider message and time efficient broadcasting and multi-broadcasting in wireless ad-hoc networks, where a subset of nodes, each with a unique rumor, wish to broadcast their rumors to all destinations while minimizing the total number of transmissions and total time until all rumors arrive to their destination. Under centralized settings, we introduce a novel approximation algorithm that provides almost optimal results with respect to the number of transmissions and total time, separately. Later on, we show how to efficiently implement this algorithm under distributed settings, where the nodes have only local information about their surroundings. In addition, we show multiple approximation techniques based on the network collision detection capabilities and explain how to calibrate the algorithms' parameters to produce optimal results for time and messages.Comment: In Proceedings FOMC 2013, arXiv:1310.459