Thermal storage technologies for solar industrial process heat applications

The state-of-the-art of thermal storage subsystems for the intermediate and high temperature (100 C to 600 C) solar industrial process heat generation is presented. Primary emphasis is focused on buffering and diurnal storage as well as total energy transport. In addition, advanced thermal storage concepts which appear promising for future solar industrial process heat applications are discussed

The 6670-Newton attitude-control thruster using hydrogen-oxygen propellant

The development of a reusable, attitude-control propulsion system for the space transportation system is discussed. A flight weight, gaseous oxygen attitude control thruster assembly was tested to obtain data on cyclic life, thermal and hydraulic characteristics, pulse response, and performance. The basic thruster components were tested in excess of 51,000 pulses and 660 seconds, steady state, with no degradation of the 93 percent characteristic exhaust velocity efficiency level. Nominal operating conditions were a chamber pressure of 207 N sq cm (300 psia), a mixture ratio of 4.0, a pulse width of 100 ms, and a pulse frequency of 2 Hz

Mod-2 wind turbine project assessment and cluster test plans

An assessment of the Mod-2 Wind Turbine project is presented based on initial goals and present results. Specifically, the Mod-2 background, project flow, and a chronology of events/results leading to Mod-2 acceptance is presented. After checkout/acceptance of the three operating turbines, NASA/LeRC will continue management of a two year test program performed at the DOE Goodnoe Hills test site. This test program is expected to yield data necessary for the continued development and optimization of wind energy systems. These test activities, the implementation of, and the results to date are also presented

Sovereign Wealth Funds: Form and Function in the 21st Century

As representatives of nation-states in global financial markets, sovereign wealth funds (SWFs) share a common form and many functions. Arguably their form and functions owe as much to a shared (global) moment of institutional formation as they owe their form and functions to the hegemony of Anglo-American finance over the late 20th and early 21st centuries. We distinguish between the immediate future for SWFs in the aftermath of the global financial crisis, and two possible long-term scenarios; one of which sees SWFs becoming financial goliaths dominating global markets, while the other sees SWFs morphing into nation-state development institutions that intermediate between financial markets and the long-term commitments of the nation-state sponsors. If the former scenario dominates, global financial integration will accelerate with attendant costs and benefits. If the latter scenario dominates, SWFs are likely to differentiate and evolve, returning, perhaps, to their national traditions and their respective places in a world of contested power and influence. Here, we clarify the assumptions underpinning the conception and formation of sovereign wealth funds over the past twenty years or so in the face of the ‘new’ realities of global finance.Sovereign Wealth Funds, Crisis, Market Performance, Long-term Investment

Solution of a statistical mechanics model for pulse formation in lasers

We present a rigorous statistical-mechanics theory of nonlinear many mode laser systems. An important example is the passively mode-locked laser that promotes pulse operation when a saturable absorber is placed in the cavity. It was shown by Gordon and Fischer [1] that pulse formation is a first-order phase transition of spontaneous ordering of modes in an effective "thermodynamic" system, in which intracavity noise level is the effective temperature. In this paper we present a rigorous solution of a model of passive mode locking. We show that the thermodynamics depends on a single parameter, and calculate exactly the mode-locking point. We find the phase diagram and calculate statistical quantities, including the dependence of the intracavity power on the gain saturation function, and finite size corrections near the transition point. We show that the thermodynamics is independent of the gain saturation mechanism and that it is correctly reproduced by a mean field calculation. The outcome is a new solvable statistical mechanics system with an unstable self-interaction accompanied by a natural global power constraint, and an exact description of an important many mode laser system.Comment: 10 pages, 3 figures, RevTe

Liquid-hydrogen rocket engine development at Aerojet, 1944 - 1950

This program demonstrated the feasibility of virtually all the components in present-day, high-energy, liquid-rocket engines. Transpiration and film-cooled thrust chambers were successfully operated. The first liquid-hydrogen tests of the coaxial injector was conducted and the first pump to successfully produce high pressures in pumping liquid hydrogen was tested. A 1,000-lb-thrust gaseous propellant and a 3,000-lb-thrust liquid-propellant thrust chamber were operated satisfactorily. Also, the first tests were conducted to evaluate the effects of jet overexpansion and separation on performance of rocket thrust chambers with hydrogen-oxygen propellants

Sipping Fuel and Saving Lives: Increasing Fuel Economy without Sacrificing Safety

Demonstrates how new fuel-efficiency technologies make it possible, and advisable, to significantly increase the fuel economy of motor vehicles without compromising their safety