41,022 research outputs found
Full Disclosure: Financial Statement Disclosures Under CERCLA
This paper presents a comprehensive mathematical framework for depletion rate analysis and ties it to the physics of depletion. Theory was compared with empirical data from 1036 fields and a number of regions. Strong agreement between theory and practice was found, indicating that the framework is plausible. Both single fields and entire regions exhibit similar depletion rate patterns, showing the generality of the approach. The maximum depletion rates for fields were found to be well described by a Weibull distribution. Depletion rates were also found to strongly correlate with decline rates. In particular, the depletion rate at peak was shown to be useful for predicting the future decline rate. Studies of regions indicate that a depletion rate of remaining recoverable resources in the range of 2–3% is consistent with historical experience. This agrees well with earlier “peak oil” forecasts and indicates that they rest on a solid scientific ground.
A steam inerting system for hydrogen disposal for the Vandenberg Shuttle
A two-year feasibility and test program to solve the problem of unburned confined hydrogen at the Vandenberg Space Launch Complex Six (SLC-6) during Space Shuttle Main Engine (SSME) firings is discussed. A novel steam inerting design was selected for development. Available sound suppression water is superheated to flash to steam at the duct entrance. Testing, analysis, and design during 1987 showed that the steam inerting system (SIS) solves the problem and meets other flight-critical system requirements. The SIS design is complete and available for installation at SLC-6 to support shuttle or derivative vehicles
In silico identification and characterisation of 17 polymorphic anonymous non-coding sequence markers (ANMs) for red grouse (Lagopus lagopus scotica)
Peer reviewedPostprin
Fire resistant coating composition Patent
Fireproof potassium silicate coating composition, insoluble in water after applicatio
General relativistic simulations of binary black hole-neutron stars: Precursor electromagnetic signals
We perform the first general relativistic force-free simulations of neutron
star (NS) magnetospheres in orbit about spinning and non-spinning black holes.
We find promising precursor electromagnetic emission: typical Poynting
luminosities at, e.g., an orbital separation of 6.6 times the NS radius are L ~
6 x 10^{42} erg/s for a 1.4 solar-mass NS with a 10^{13}G polar magnetic field.
The Poynting flux peaks within a broad beam of ~40 degrees in the azimuthal
direction and within ~60 degrees from the orbital plane, establishing a
possible lighthouse effect. Our calculations, though preliminary, preview more
detailed simulations of these systems that we plan to perform in the future.Comment: 6 pages, 4 figures, matches published version in PRD Rapid
Communications, two references fixe
Reionization of Hydrogen and Helium by Early Stars and Quasars
We compute the reionization histories of hydrogen and helium due to the
ionizing radiation fields produced by stars and quasars. For the quasars we use
a model based on halo-merger rates that reproduces all known properties of the
quasar luminosity function at high redshifts. The less constrained properties
of the ionizing radiation produced by stars are modeled with two free
parameters: (i) a transition redshift, z_tran, above which the stellar
population is dominated by massive, zero-metallicity stars and below which it
is dominated by a Scalo mass function; (ii) the product of the escape fraction
of stellar ionizing photons from their host galaxies and the star-formation
efficiency, f_esc f_*. We constrain the allowed range of these free parameters
at high redshifts based on the lack of the HI Gunn-Peterson trough at z<6 and
the upper limit on the total intergalactic optical depth for electron
scattering, tau_es<0.18, from recent cosmic microwave background (CMB)
experiments. We find that quasars ionize helium by a redshift z~4, but cannot
reionize hydrogen by themselves before z~6. A major fraction of the allowed
combinations of f_esc f_* and z_tran lead to an early peak in the ionized
fraction due to metal-free stars at high redshifts. This sometimes results in
two reionization epochs, namely an early HII or HeIII overlap phase followed by
recombination and a second overlap phase. Even if early overlap is not
achieved, the peak in the visibility function for scattering of the CMB often
coincides with the early ionization phase rather than with the actual
reionization epoch. Consequently, tau_es does not correspond directly to the
reionization redshift. We generically find values of tau_es>7%, that should be
detectable by the MAP satellite.Comment: 33 pages, 10 figures, Accepted for publication in Ap
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