We give a randomized O(n polylog n)-time approximation scheme for the Steiner forest problem in the Euclidean plane. For every fixed ε > 0 and given n terminals in the plane with connection requests between some pairs of terminals, our scheme finds a (1 + ε) approximation to the minimum-length...
Oxygen and strontium isotopic composition of sedimentary pore fluids obtained by drilling at the Chile Triple Junction have been used to obtain information on the diagenesis and transport mechanisms of fluids. Samples were collected from three sites located on an east-west transect of the pre-collision zone (Sites 859, 860, and...
The impact of anthropogenic forcing on the probability of high mean summer temperatures being exceeded in Texas in the year 2011 was investigated using an atmospheric circulation model to simulate large ensembles of the world with 2011 level forcing and 5 counterfactual worlds under preindustrial forcing. In Texas, drought is...
Full Text:
David
E.
Rupp1,
Sihan
Li1,
Neil
Massey2,
Sarah
N.
Sparrow2,
Philip
W
The impact of anthropogenic forcing on the probability of high mean summer temperatures being exceeded in Texas in the year 2011 was investigated using an atmospheric circulation model to simulate large ensembles of the world with 2011 level forcing and 5 counterfactual worlds under preindustrial forcing. In Texas, drought is...
Full Text:
summer in Texas, 2011
David E. Rupp1, Sihan Li1, Neil Massey2, Sarah N. Sparrow2, Philip W. Mote1, and
The impact of anthropogenic forcing on the probability of high mean summer temperatures being exceeded in Texas in the year 2011 was investigated using an atmospheric circulation model to simulate large ensembles of the world with 2011 level forcing and 5 counterfactual worlds under preindustrial forcing. In Texas, drought is...
Sedimentary pore fluids from the Chile Triple Junction were sampled in situ, and analyzed for their noble gas composition. ³He/⁴He and ⁴He/Ne ratios were used to evaluate the fraction of helium in the samples that originated from mantle and radiogenic sources. The results show no primordial helium in samples recovered...
Coring at ODP Sites 859, 860, and 861 near the Chile Triple Junction failed to recover anticipated gas hydrate that was inferred
to be present from two lines of geophysical evidence: pre-cruise observation of a weak to strong bottom simulating reflector (BSR)
marking the predicted base of the gas-hydrate stability...
Natural gas extraction, often referred to as “fracking,” has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped...
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extraction on PAH levels in ambient air
L. Blair Paulik†, Carey E. Donald†, Brian W. Smith†, Lane G
Natural gas extraction, often referred to as “fracking,” has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped...
Full Text:
Paulik†, Carey E. Donald†, Brian W. Smith†, Lane G. Tidwell†, Kevin A. Hobbie†, Laurel
Kincl‡, Erin N