26,340 research outputs found
Metal alloy resistivity measurements at very low temperatures
High speed, automated system accurately measures to approximately one percent in three minutes. System identifies materials having constant thermal or electric conductivity, predicts new material properties, develops alloys in accordance with desired specifications, and develops nondestructive devices for measuring precipitation hardening
Observation of Single Transits in Supercooled Monatomic Liquids
A transit is the motion of a system from one many-particle potential energy
valley to another. We report the observation of transits in molecular dynamics
(MD) calculations of supercooled liquid argon and sodium. Each transit is a
correlated simultaneous shift in the equilibrium positions of a small local
group of particles, as revealed in the fluctuating graphs of the particle
coordinates versus time. This is the first reported direct observation of
transit motion in a monatomic liquid in thermal equilibrium. We found transits
involving 2 to 11 particles, having mean shift in equilibrium position on the
order of 0.4 R_1 in argon and 0.25 R_1 in sodium, where R_1 is the nearest
neighbor distance. The time it takes for a transit to occur is approximately
one mean vibrational period, confirming that transits are fast.Comment: 19 pages, 8 figure
Decentralization in the EU Emissions Trading Scheme and Lessons for Global Policy
In 2005, the European Union introduced the largest and most ambitious emissions trading program in the world to meet its Kyoto commitments for the containment of global climate change. The EU Emissions Trading Scheme (EU ETS) has some distinctive features that differentiate it from the more standard model of emissions trading. In particular, it has a relatively decentralized structure that gives individual member states responsibility for setting targets, allocating permits, determining verification and enforcement, and making some choices about flexibility. It is also a “cap-within-a-cap,” seeking to achieve the Kyoto targets while only covering about half of EU emissions. Finally, it is a program that many hope will link with other greenhouse gas trading programs in the future—something we have not seen among existing trading systems. Examining these features coupled with recent EU ETS experience offers lessons about how cost effectiveness, equity, flexibility, and compliance fare in a multi-jurisdictional trading program, and highlights the challenges facing a global emissions trading regime.emissions trading, Kyoto Protocol, European Union, linking, climate change
Do the electromagnetic fields generated by mobile-phone base-stations have short-term effects on health? A response to commentaries
Are Energy Efficiency Standards Justified?
This paper develops and parameterizes an overarching analytical framework to estimate the welfare effects of energy efficiency standards applied to automobiles and electricity-using durables. We also compare standards with sectoral and economywide pricing policies. The model captures a wide range of externalities and preexisting energy policies, and it allows for possible “misperceptions”—market failures that cause underinvestment in energy efficiency.Automobile fuel economy standards are not part of the first-best policy to reduce gasoline: fuel taxes are always superior because they reduce the externalities related to vehicle miles traveled. For the power sector, potential welfare gains from supplementing pricing instruments with efficiency standards are small at best. If pricing instruments are not feasible, a large misperceptions failure is required to justify efficiency standards, and even in this case the optimal reductions in fuel and electricity use are relatively modest. Reducing economywide carbon dioxide emissions through regulatory packages (combining efficiency and emissions standards) involves much higher costs than pricing instruments.standards, energy taxes, market failure, climate, power sector, gasoline
A summary of the test procedures and operational details of an ocean dumping pollution monitoring experiment conducted 7 October 1976
A remote sensor experiment was conducted at a sewage sludge dump site off the Delaware/Maryland coast. Two aircraft serving as remote sensor platforms flew over the dump site during a sludge dump. One aircraft carried a multispectral scanner and the other aircraft carried a rapid scanning spectrometer. Data from sea-truth stations were collected concurrent with overpasses of the aircraft. All sensors were operational and produced good digital data
Oxidation characteristics of Beta-21S in air in the temperature range 600 to 800 C
The metastable beta-Ti alloy Beta-21S, Ti-15Mo-2.7Nb-3Al-0.2Si (weight percent), has been proposed as a candidate for use in metal matrix composites in future hypersonic vehicles. The present study investigated the oxidation behavior of Beta-21S over the temperature range 600 C to 800 C. Oxidation weight gain was evaluated using thermogravimetric analysis. Oxidized specimens were evaluated using x ray diffraction techniques, scanning electron microscopy, energy dispersive x ray analysis, and electron microprobe analysis to identify oxidation products and evaluate oxidation damage to the alloy
Electromagnetic Scattering from Relativistic Bound States
The quasipotential formalism for elastic scattering from relativistic bound
states is formulated based on the instant constraint in the Breit frame. The
quasipotential electromagnetic current is derived from Mandelstam's five-point
kernel and obeys a two-body Ward identity. Breit-frame wave functions are
obtained directly by solving integral equations with nonzero total
three-momentum, thus accomplishing a dynamical boost. Calculations of
electron-deuteron elastic form factors illustrate the importance of the
dynamical boost versus kinematic boosts of the rest frame wave functions.Comment: RevTeX 3.0 manuscript, 9 pages. UU-file is a single PostScript file
of the manuscript including figures. U. MD PP #93-17
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