Transverse microcracking in Celion 6000/PMR-15 graphite-polyimide

The effects of room temperature tensile loading and five thermal loadings, in the range -320 F (-196C) to 625F (330CC), upon the development of transverse microcracks (TVM) in Celion 6000/PMR-15 graphite-polyimide laminates were investigated. Microcracks were observed using a replicating technique, microscopy and X-ray. The mechanical or thermal load at which microcracking initiates and the ply residual stresses were predicted using laminate analysis with stress- and temperature-dependent material properties

An experimental/analytical program to assess the utility of lidar for pollution monitoring

The development and demonstration of lidar techniques for the remote measurement of atmospheric constituents and transport processes in the lower troposphere was carried out. Particular emphasis was given to techniques for monitoring SO2 and particulates, the principal pollutants in power plant and industrial plumes. Data from a plume dispersion study conducted in Maryland during September and October 1976 were reduced, and a data base was assembled which is available to the scientific community for plume model verification. A UV Differential Absorption Lidar (DIAL) was built, and preliminary testing was done

A Roadmap for Change: Federal Policy Recommendations for Addressing the Criminilization of LGBT People and People Living with HIV

Each year in the United States, thousands of lesbian, gay, bisexual, transgender, Two Spirit, queer, questioning and gender non-conforming (LGBT) people and people living with HIV come in contact with the criminal justice system and fall victim to similar miscarriages of justice.According to a recent national study, a startling 73% of all LGBT people and PLWH surveyed have had face-to-face contact with police during the past five years.1 Five percent of these respondents also report having spent time in jail or prison, a rate that is markedly higher than the nearly 3% of the U.S. adult population whoare under some form of correctional supervision (jail, prison, probation, or parole) at any point in time.In fact, LGBT people and PLWH, especially Native and LGBT people and PLWH of color, aresignificantly overrepresented in all aspects of the penal system, from policing, to adjudication,to incarceration. Yet their experiences are often overlooked, and little headway has been madein dismantling the cycles of criminalization that perpetuate poor life outcomes and push already vulnerable populations to the margins of society.The disproportionate rate of LGBT people and PLWH in the criminal system can best be understoodin the larger context of widespread and continuing discrimination in employment, education, socialservices, health care, and responses to violence

Abundant Methanol Masers but no New Evidence for Star Formation in GCM0.253+0.016

We present new observations of the quiescent giant molecular cloud GCM0.253+0.016 in the Galactic center, using the upgraded Karl G. Jansky Very Large Array. Observations were made at wavelengths near 1 cm, at K (24 to 26 GHz) and Ka (27 and 36 GHz) bands, with velocity resolutions of 1-3 km/s and spatial resolutions of ~0.1 pc, at the assumed 8.4 kpc distance of this cloud. The continuum observations of this cloud are the most sensitive yet made, and reveal previously undetected emission which we attribute primarily to free-free emission from external ionization of the cloud. In addition to the sensitive continuum map, we produce maps of 12 molecular lines: 8 transitions of NH3 -- (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7) and (9,9), as well as the HC3N (3-2) and (4-3) lines, and CH3OH 4(-1) - 3(0) the latter of which is known to be a collisionally-excited maser. We identify 148 CH3OH 4(-1) - 3(0) (36.2 GHz) sources, of which 68 have brightness temperatures in excess of the highest temperature measured for this cloud (400 K) and can be confirmed to be masers. The majority of these masers are concentrated in the southernmost part of the cloud. We find that neither these masers nor the continuum emission in this cloud provide strong evidence for ongoing star formation in excess of that previously inferred by the presence of an H2O maser.Comment: 33 pages, 4 tables, 9 figures; ApJ Accepte

Epitaxial Ferromagnetic Nanoislands of Cubic GdN in Hexagonal GaN

Periodic structures of GdN particles encapsulated in a single crystalline GaN matrix were prepared by plasma assisted molecular beam epitaxy. High resolution X-ray diffractometery shows that GdN islands, with rock salt structure are epitaxially oriented to the wurtzite GaN matrix. Scanning transmission electron microscopy combined with in-situ reflection high energy electron diffraction allows for the study of island formation dynamics, which occurs after 1.2 monolayers of GdN coverage. Magnetometry reveals two ferromagnetic phases, one due to GdN particles with Curie temperature of 70K and a second, anomalous room temperature phase.Comment: 4 pages, 3 figure

Quantum ratchet transport with minimal dispersion rate

We analyze the performance of quantum ratchets by considering the dynamics of an initially localized wave packet loaded into a flashing periodic potential. The directed center-of-mass motion can be initiated by the uniform modulation of the potential height, provided that the modulation protocol breaks all relevant time- and spatial reflection symmetries. A poor performance of quantum ratchet transport is characterized by a slow net motion and a fast diffusive spreading of the wave packet, while the desirable optimal performance is the contrary. By invoking a quantum analog of the classical P\'eclet number, namely the quotient of the group velocity and the dispersion of the propagating wave packet, we calibrate the transport properties of flashing quantum ratchets and discuss the mechanisms that yield low-dispersive directed transport.Comment: 6 pages; 3 figures; 1 tabl

A Better Definition of the Kilogram

This article reviews several recent proposed redefinitions of the kilogram, and compares them with respect to practical realizations, uncertainties (estimated standard deviations), and educational aspects.Comment: 10 pages, no figure

Predictors of tonsillectomy after previous adenoidectomy for upper airway obstruction [abstract]

One of the main indications for adenotonsillectomy in children is upper airway obstruction, including obstructive sleep apnea. Previous research has suggested an increased risk for requiring subsequent tonsillectomy when adenoidectomy alone is performed for upper airway obstruction. The purpose of this study is to further characterize potential risk factors for subsequent tonsillectomy in pediatric patients undergoing adenoidectomy for upper airway obstruction