2,787 research outputs found
The Status of a PA Endangered Bird- the Upland Sandpiper
The upland sandpiper (Bartramia Longuardia) has experienced a steep population decline in the northeastern U.S. since the mid-20th Century. In Pennsylvania it was found in less than 0.5% of atlas blocks during the Second Atlas of Breeding Birds in Pennsylvania project (2nd PBBA; 2004-09) and breeding was confirmed at only two locations. Due to continued declines and a small population size, the upland sandpiper was listed as PA endangered in 2012. During May 2012 the areas around 15 2nd PBBA upland sandpiper sightings were resurveyed by Gettysburg College students and volunteer birdwatchers. The aim was to establish whether the atlas records related to persisting populations. We used five-minute audio playback at up to 10 locations within 4km of the atlas sightings. A maximum of 19 pairs/calling male upland sandpipers were found across the state in 2012, most of them on or close to reclaimed surface mines. However, locating such a scarce species can be problematic, and it is still not known to what extent the species is under-reported. To help direct future surveys we analyzed data from the 2nd PBBA and the 2012 survey to produce a habitat suitability model for the upland sandpiper in Pennsylvania. We used a GIS framework to determine areas of suitable habitat and then stratified these by proximity to recent (2004-2012) upland sandpiper sightings. We recommend that our suitability model be used to establish a sampling protocol for more thorough statewide upland sandpiper survey every five years, in order that the species’ precarious status can be closely monitored
Mass-radius relation for magnetized strange quark stars
We review the stability of magnetized strange quark matter (MSQM) within the
phenomenological MIT bag model, taking into account the variation of the
relevant input parameters, namely, the strange quark mass, baryon density,
magnetic field and bag parameter. A comparison with magnetized asymmetric quark
matter in -equilibrium as well as with strange quark matter (SQM) is
presented. We obtain that the energy per baryon for MSQM decreases as the
magnetic field increases, and its minimum value at vanishing pressure is lower
than the value found for SQM, which implies that MSQM is more stable than
non-magnetized SQM. The mass-radius relation for magnetized strange quark stars
is also obtained in this framework.Comment: 7 pages, 6 figures. To be published in the Proceedings of 4th
International Workshop on Relativistic Astrophysical and Astronomy IWARA0
Real-time profiling of organic trace gases in the planetary boundary layer by PTR-MS using a tethered balloon
A method for real-time profiling of volatile organic compounds (VOCs) was developed combining the advantages of a tethered balloon as a research platform and of proton transfer reaction mass spectrometry (PTR-MS) as an analytical technique for fast and highly sensitive VOC measurements. A 200 m Teflon tube was used to draw sampling air from a tethered aerodynamic balloon to the PTR-MS instrument. Positive and negative artefacts (i.e. formation and loss of VOCs in the tube) were characterised in the laboratory and in the field by a set of 11 atmospherically relevant VOCs including both pure and oxygenated hydrocarbons. The only two compounds that increased or decreased when sampled through the tube were acetone (+7%) and xylene (-6%). The method was successfully deployed during a winter field campaign to determine the small scale spatial and temporal patterns of air pollutants under winter inversion conditions
Temperature effects on the magnetization of quasi-one-dimensional Peierls distorted materials
It is shown that temperature acts to disrupt the magnetization of Peierls
distorted quasi-one-dimensional materials (Q1DM). The mean-field finite
temperature phase diagram for the field theory model employed is obtained by
considering both homogeneous and inhomogeneous condensates. The tricritical
points of the second order transition lines of the gap parameter and
magnetization are explicitly calculated. It is also shown that in the absence
of an external static magnetic field the magnetization is always zero, at any
temperature. As expected, temperature does not induce any magnetization effect
on Peierls distorted Q1DM.Comment: 11 pages, 2 figure
Caracterização de madeiras por pirólise com sililação on-line acoplada à cromatografia gasosa e espectrometria de massas.
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