962 research outputs found
Reply to comment by S. Han and F. Tian on A calibration-free formulation of the complementary relationship of evaporation for continental-scale hydrology
Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger - United States, 2019
Balancing Justice and Mercy: Redemptive Ways of Dealing With Adolescent Substance Abuse
This article will briefly describe the range of policies relating to drug or substance possession and use that are found in the boarding and day academies of the Lake Union Conference (in the North American Division). Next, we will deal with the areas of screening, discipline, and referral to appropriate services. Finally, using case examples of two very different student experiences with illegal substances, we will offer some policy recommendations for dealing redemptively with substance abuse by students
Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger - United States, 2020
A fast stroboscopic spectral method for rotating systems in numerical relativity
We present a numerical technique for solving evolution equations, as the wave
equation, in the description of rotating astrophysical compact objects in
comoving coordinates, which avoids the problems associated with the light
cylinder. The technique implements a fast spectral matching between two domains
in relative rotation: an inner spherical domain, comoving with the sources and
lying strictly inside the light cylinder, and an outer inertial spherical
shell. Even though the emphasis is placed on spectral techniques, the matching
is independent of the specific manner in which equations are solved inside each
domain, and can be adapted to different schemes. We illustrate the strategy
with some simple but representative examples.Comment: 16 pages, 15 figure
Modeling Gravitational Recoil Using Numerical Relativity
We review the developments in modeling gravitational recoil from merging
black-hole binaries and introduce a new set of 20 simulations to test our
previously proposed empirical formula for the recoil. The configurations are
chosen to represent generic binaries with unequal masses and precessing spins.
Results of these simulations indicate that the recoil formula is accurate to
within a few km/s in the similar mass-ratio regime for the out-of-plane recoil.Comment: corrections to text, 11 pages, 1 figur
Formation and growth characteristics of nanostructured carbon films on nascent Ag clusters during room-temperature electrochemical CO2 reduction
Synthesis of carbon nanostructures at room temperature and under atmospheric pressure is challenging but it can provide significant impact on the development of many future advanced technologies. Here, the formation and growth characteristics of nanostructured carbon films on nascent Ag clusters during room-temperature electrochemical CO(2) reduction reactions (CO(2)RR) are demonstrated. Under a ternary electrolyte system containing [BMIm](+)[BF(4)](−), propylene carbonate, and water, a mixture of sp(2)/sp(3) carbon allotropes were grown on the facets of Ag nanocrystals as building blocks. We show that (i) upon sufficient energy supplied by an electric field, (ii) the presence of negatively charged nascent Ag clusters, and (iii) as a function of how far the C–C coupling reaction of CO(2)RR (10–390 min) has advanced, the growth of nanostructured carbon can be divided into three stages: Stage 1: sp(3)-rich carbon and diamond seed formation; stage 2: diamond growth and diamond–graphite transformation; and stage 3: amorphous carbon formation. The conversion of CO(2) and high selectivity for the solid carbon products (>95%) were maintained during the full CO(2)RR reaction length of 390 min. The results enable further design of the room-temperature production of nanostructured carbon allotropes and/or the corresponding metal-composites by a viable negative CO(2) emission technology
Exact Solutions for the Intrinsic Geometry of Black Hole Coalescence
We describe the null geometry of a multiple black hole event horizon in terms
of a conformal rescaling of a flat space null hypersurface. For the prolate
spheroidal case, we show that the method reproduces the pair-of-pants shaped
horizon found in the numerical simulation of the head-on-collision of black
holes. For the oblate case, it reproduces the initially toroidal event horizon
found in the numerical simulation of collapse of a rotating cluster. The
analytic nature of the approach makes further conclusions possible, such as a
bearing on the hoop conjecture. From a time reversed point of view, the
approach yields a description of the past event horizon of a fissioning white
hole, which can be used as null data for the characteristic evolution of the
exterior space-time.Comment: 21 pages, 6 figures, revtex, to appear in Phys. Rev.
Initial data transients in binary black hole evolutions
We describe a method for initializing characteristic evolutions of the
Einstein equations using a linearized solution corresponding to purely outgoing
radiation. This allows for a more consistent application of the characteristic
(null cone) techniques for invariantly determining the gravitational radiation
content of numerical simulations. In addition, we are able to identify the {\em
ingoing} radiation contained in the characteristic initial data, as well as in
the initial data of the 3+1 simulation. We find that each component leads to a
small but long lasting (several hundred mass scales) transient in the measured
outgoing gravitational waves.Comment: 18 pages, 4 figure
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