CO chemisorption on Ir(111)

The adsorption of carbon monoxide on the (111) crystallographic orientation of iridium both at and below room temperature has been investigated using both low‐energy electron diffraction (LEED) and thermal desorption mass spectrometry. At room temperature, CO adsorbs rapidly resulting in the appearance of a faint (√3×√3) R30° LEED pattern after only approximately 1.3×10^(−6) Torr s (1.72×10^(−4) Pa s) exposure. Upon further exposure to CO, the intensity of the overlayer LEED beams initially increases, but then decreases passing through a maximum at an exposure of approximately 2.4×10^(−6) Torr s (3.2×10^(−4) Pa s). By an exposure of 10^(−5) Torr s (1.3×10^(−3) Pa s) each of the (rather dim and diffuse) overlayer beams has split into two beams. These beams then move toward the substrate beams with increasing CO surface coverage, until near saturation coverage the angle between the split overlayer beams subtended at the (00) beam is greater than 30°

A waypoint-based mission planner for a farmland coverage with an aerial robot - a precision farming tool

Remote sensing (RS) with aerial robots is becoming more usual in every day time in Precision Agriculture (PA) practices, do to their advantages over conventional methods. Usually, available commercial platforms providing off-the-shelf waypoint navigation are adopted to perform visual surveys over crop fields, with the purpose to acquire specific image samples. The way in which a waypoint list is computed and dispatched to the aerial robot when mapping non empty agricultural workspaces has not been yet discussed. In this paper we propose an offline mission planner approach that computes an efficient coverage path subject to some constraints by decomposing the environment approximately into cells. Therefore, the aim of this work is contributing with a feasible waypoints-based tool to support PA practice

Prior Authorization as a Potential Support of Patient-Centered Care.

We discuss the role of prior authorization (PA) in supporting patient-centered care (PCC) by directing health system resources and thus the ability to better meet the needs of individual patients. We begin with an account of PCC as a standard that should be aimed for in patient care. In order to achieve widespread PCC, appropriate resource management is essential in a healthcare system. This brings us to PA, and we present an idealized view of PA in order to argue how at its best, it can contribute to the provision of PCC. PA is a means of cost saving and as such it has mixed success. The example of the US demonstrates how implementation of PA has increased health inequalities whereas best practice has the potential to reduce them. In contrast, systems of universal coverage, like those in Europe, may use the cost savings of PA to better address individuals' care and PCC. The conclusion we offer therefore is an optimistic one, pointing towards areas of supportive overlap between PCC and PA where usually the incongruities are most evident

Low-temperature Molecular Beam Epitaxy of GaAs: A Theoretical Investigation of Antisite Incorporation and Reflection High-energy Diffraction Oscillations

Surface dynamics dominate the incorporation of charged, As+Ga, and neutral, As0Ga, antisite arsenic, and the temporal variation of reflection high-energy electron diffraction(RHEED) intensity in the low-temperature molecular beam epitaxy of (100) gallium arsenide(GaAs). A rate equation model is proposed which includes the presence and dynamics of a physisorbed arsenic (PA) layer riding the growth surface. The PA layer dictates the incorporation and concentration of As+Ga and As0Ga. Additionally, it influences the RHEED oscillations (ROs) behavior and the RO’s dependence on its coverage through its contribution to the reflected intensity. The model results for the dependence of As+Ga and As0Ga concentrations on beam equivalent pressure (BEP) and growth temperature are in good agreement with experimental data. The experimental observations can be explained based on the saturation of the PA coverage at one monolayer and the competing rate processes such as the AsGa incorporation into and evaporation from the crystalline surface. Using the same kinetic model for the temporal behavior of the surface, the contribution of the PA layer to the RHEED intensity is computed based on kinematical theory of electron diffraction. The experimental observation of the ROs during growth at high and low temperatures with no ROs in the intermediate temperature range of 300–450 °C is in good agreement with our model results. At low temperatures, the surface is covered by the PA layer whose step density depends on that of the subsurface crystalline GaAs. Thus, a temporal variation of the step density of subsurface crystalline GaAs results in ROs, but with a different step height, that of the PA layer, of 2.48 Å. At high temperatures, the crystalline GaAs is exposed to the RHEED beam due to the evaporation of the PA layer and the ROs appear due to periodic step-density oscillations with a step height of 1.41 Å, which is the Ga–As crystalline interplanar distance. At intermediate temperatures, the surface is partially covered by the PA layer resulting in RHEED reflection contributions from both surfaces covered by the PA layer and crystal. Due to the very different interplanar distances between the crystalline GaAs and the PA layers, complete destructive interference of the RHEED intensity results at a 0.5 surface coverage of the PA layer. The RO dependence on the As BEP is also presented and discussed

Resolving the nucleus of Centaurus A at mid-IR wavelengths

We have observed Centaurus A with the MID-infrared Interferometric instrument (MIDI) at the Very Large Telescope Interferometer (VLTI) at resolutions of 7 - 15 mas (at 12.5 micron) and filled gaps in the (u,v) coverage in comparison to earlier measurements. We are now able to describe the nuclear emission in terms of geometric components and derive their parameters by fitting models to the interferometric data. With simple geometrical models, the best fit is achieved for an elongated disk with flat intensity profile with diameter 76 +/- 9 mas x 35 +/- 2 mas (1.41 +/- 0.17 pc x 0.65 +/- 0.03 pc) whose major axis is oriented at a position angle (PA) of 10.1 +/- 2.2 degrees east of north. A point source contributes 47 +/- 11 % of the nuclear emission at 12.5 micron. There is also evidence that neither such a uniform nor a Gaussian disk are good fits to the data. This indicates that we are resolving more complicated small-scale structure in AGNs with MIDI, as has been seen in Seyfert galaxies previously observed with MIDI. The PA and inferred inclination i = 62.6 +2.1/-2.6 degrees of the dust emission are compared with observations of gas and dust at larger scales.Comment: Accepted for the PASA special issue on Centaurus

Shortfalls and Solutions for Meeting National and Global Conservation Area Targets

Governments have committed to conserving 17% of terrestrial and 10% of marine environments globally, especially “areas of particular importance for biodiversity” through “ecologically representative” Protected Area (PA) systems or other “area-based conservation measures”, while individual countries have committed to conserve 3–50% of their land area. We estimate that PAs currently cover 14.6% of terrestrial and 2.8% of marine extent, but 59–68% of ecoregions, 77–78% of important sites for biodiversity, and 57% of 25,380 species have inadequate coverage. The existing 19.7 million km2 terrestrial PA network needs only 3.3 million km2 to be added to achieve 17% terrestrial coverage. However, it would require nearly doubling to achieve, costefficiently, coverage targets for all countries, ecoregions, important sites, and species. Poorer countries have the largest relative shortfalls. Such extensive and rapid expansion of formal PAs is unlikely to be achievable. Greater focus is therefore needed on alternative approaches, including community- and privately managed sites and other effective area-based conservation measures.We are grateful to the many individuals and organizations who contribute to the IUCN Red List of Threatened Species,WDPA, or to identification of IBAs or AZEs. We thank A. Bennett for help with data collation and N. Dulvy, W. Laurance, and D. Faith for helpful comments on an earlier draft. This work was supported by the Cambridge Conservation Initiative Collaborative Fund and Arcadia.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/conl.1215

Evaluation on efficiency of pyroligneous acid from palm kernel shell as antifungal and solid pineapple biomass as antibacterial and Plant Growth Promoter

Generation of huge volumes of lignocellulosic biomass from agricultural sector is of concern due to its direct effects on the depletion of overall environmental quality. Conversion of biomass into solid biofuel through pyrolysis reaction has become one of the solutions to manage the abundance of biomass. Pyroligneous acid (PA) produced from the condensation of smoke generated during biomass carbonization process has the potential to be applied in various applications based on the diverse active chemical compounds present. In this study, PA obtained from palm kernel shell (PKS) was evaluated for antifungal activity and solid pineapple biomass (PB) was evaluated for antibacterial and plant growth promoter activities. Higher antifungal activity was determined for crude PA from PKS (PA-PKS) and dichloromethane-extract (DPA-PKS) with 0% coverage area when evaluated using rubber wood blocks against mold and blue sapstain after for 4 weeks of observation. This antifungal activity can be attributed to the presence of phenols and its major derivatives as suggested from the GC-MS and FTIR analysis. Concentrated PA from PB displayed good antibacterial capabilities with almost similar growth inhibition for Escherichia coli (13±1 to 20±1 mm) and Corynebacterium agropyri (20±1 mm). PA-PB also showed good potential as PGP where the addition of 2% (v/v) of PA-PB into the fertilizer for okra plant resulted in highest number of leaves and fruits while 4% (v/v) PA-PB managed to give highest plant height, longest root, heaviest fruits and biggest leaf diameter. Thus, thi

Employment-Based Health Insurance: 2010

[Excerpt] This report uses data from the Survey of Income and Program Participation (SIPP) to examine the characteristics of people with employer-provided health insurance coverage as well as characteristics of employers that offer health insurance. This documentation of the current distribution of employment-based health insurance coverage across socioeconomic characteristics is needed to establish the changes associated with recent health care legislation. The report is composed of two sections. The first section provides a brief overview of historical trends in employer-provided coverage rates by source of coverage as well as the reasons for nonparticipation in health insurance from 1997 to 2010. The second section focuses on data collected in 2010 and describes health insurance offer and take-up rates by employee and employer characteristics. In addition, the report describes the insurance status of workers not participating in an employer’s plan and the reasons for nonparticipation

User-Centric Interference Nulling in Downlink Multi-Antenna Heterogeneous Networks

In heterogeneous networks (HetNets), strong interference due to spectrum reuse affects each user's signal-to-interference ratio (SIR), and hence is one limiting factor of network performance. In this paper, we propose a user-centric interference nulling (IN) scheme in a downlink large-scale HetNet to improve coverage/outage probability by improving each user's SIR. This IN scheme utilizes at most maximum IN degree of freedom (DoF) at each macro-BS to avoid interference to uniformly selected macro (pico) users with signal-to-individual-interference ratio (SIIR) below a macro (pico) IN threshold, where the maximum IN DoF and the two IN thresholds are three design parameters. Using tools from stochastic geometry, we first obtain a tractable expression of the coverage (equivalently outage) probability. Then, we analyze the asymptotic coverage/outage probability in the low and high SIR threshold regimes. The analytical results indicate that the maximum IN DoF can affect the order gain of the outage probability in the low SIR threshold regime, but cannot affect the order gain of the coverage probability in the high SIR threshold regime. Moreover, we characterize the optimal maximum IN DoF which optimizes the asymptotic coverage/outage probability. The optimization results reveal that the IN scheme can linearly improve the outage probability in the low SIR threshold regime, but cannot improve the coverage probability in the high SIR threshold regime. Finally, numerical results show that the proposed scheme can achieve good gains in coverage/outage probability over a maximum ratio beamforming scheme and a user-centric almost blank subframes (ABS) scheme.Comment: Transactions on Wireless Communications (under revision). arXiv admin note: text overlap with arXiv:1504.0528