The Influence of Soil Moisture Conditions on the Absorption of Phosphorus by Plants from Calcareous Soils

Relationship between soil moisture and the absorption of phosphorus and other nutrients

Radar altimetry systems cost analysis

This report discusses the application and cost of two types of altimeter systems (spaceborne (satellite and shuttle) and airborne) to twelve user requirements. The overall design of the systems defined to meet these requirements is predicated on an unconstrained altimetry technology; that is, any level of altimeter or supporting equipment performance is possible

Transient extreme ultraviolet measurement of element-specific charge transfer dynamics in multiple-material junctions

The absorption of solid state materials in complex photonic and optoelectronic devices overlap in the visible spectrum. Due to the overlap of spectral features, ultrafast measurements of charge carrier dynamics and transport is obscured. Here, the element specificity of transient extreme ultraviolet (XUV) spectroscopy is advanced as a probe for studying photoexcited charge transport in multiple-material junctions. The core-hole excited by the XUV transitions also imparts structural information on to the probed electronic transition. Transient XUV can therefore measure electron and averaged phonon dynamics for each elemental species in a junction. Application to polaron measurement in α-Fe_2O_3, valley-specific scattering in Si, and charge transfer in a nanoscale Ni-TiO_2-Si junction will be discussed

Timing analysis techniques at large core distances for multi-TeV gamma ray astronomy

We present an analysis technique that uses the timing information of Cherenkov images from extensive air showers (EAS). Our emphasis is on distant, or large core distance gamma-ray induced showers at multi-TeV energies. Specifically, combining pixel timing information with an improved direction reconstruction algorithm, leads to improvements in angular and core resolution as large as ~40% and ~30%, respectively, when compared with the same algorithm without the use of timing. Above 10 TeV, this results in an angular resolution approaching 0.05 degrees, together with a core resolution better than ~15 m. The off-axis post-cut gamma-ray acceptance is energy dependent and its full width at half maximum ranges from 4 degrees to 8 degrees. For shower directions that are up to ~6 degrees off-axis, the angular resolution achieved by using timing information is comparable, around 100 TeV, to the on-axis angular resolution. The telescope specifications and layout we describe here are geared towards energies above 10 TeV. However, the methods can in principle be applied to other energies, given suitable telescope parameters. The 5-telescope cell investigated in this study could initially pave the way for a larger array of sparsely spaced telescopes in an effort to push the collection area to >10 km2. These results highlight the potential of a `sparse array' approach in effectively opening up the energy range above 10 TeV.Comment: Published in Astroparticle Physic

Examining the shared and unique features of self-concept content and structure in Borderline Personality Disorder and Depression

AcceptedArticleCopyright © Springer Science+Business Media New York 2015The online version of this article (doi:10.1007/s10608-015-9695-3) contains supplementary material, which is available to authorized users.A number of clinical theories emphasise self-concept disturbance as central to borderline personality disorder (BPD). To date, however, there has been limited empirical examination of exactly how BPD changes the content and structure of self-concept. Moreover, it is unclear if patterns of self-concept disturbance are unique to BPD or are driven by axis-I comorbidities such as depression. To examine this issue, the present study adopted a dimensional design, examining how performance on a novel adaptation of a well-validated measure of self-concept (the Psychological Distance Scaling Task) was related to BPD and depression symptoms in a sample of 93 individuals with a wide range of symptom severity. While greater BPD severity was associated with less positive and more negative content of self-concept, this was driven by depression symptoms. Similarly, positive content was more diffuse and negative content more interconnected at higher levels of BPD severity, but for positive content, this was most clearly linked to comorbid depression features. In contrast, BPD severity (over and above depression symptoms) was uniquely associated with greater ‘clustering’ for positive and negative content (i.e. a more fragmented self-concept). This pattern of results lends support to clinical theories arguing that self-concept fragmentation is core to BPD and also supports the utility of dimensional analyses to identify patterns of cognitive-affective disturbance unique to BPD versus those shared with comorbid conditions like depression.MR

Advanced engine study program

A design and analysis study was conducted to provide advanced engine descriptions and parametric data for space transfer vehicles. The study was based on an advanced oxygen/hydrogen engine in the 7,500 to 50,000 lbf thrust range. Emphasis was placed on defining requirements for high-performance engines capable of achieving reliable and versatile operation in a space environment. Four variations on the expander cycle were compared, and the advantages and disadvantages of each were assessed. Parametric weight, envelope, and performance data were generated over a range of 7,500 to 50,000 lb thrust and a wide range of chamber pressure and nozzle expansion ratio

Transient extreme ultraviolet measurement of element-specific charge transfer dynamics in multiple-material junctions

The absorption of solid state materials in complex photonic and optoelectronic devices overlap in the visible spectrum. Due to the overlap of spectral features, ultrafast measurements of charge carrier dynamics and transport is obscured. Here, the element specificity of transient extreme ultraviolet (XUV) spectroscopy is advanced as a probe for studying photoexcited charge transport in multiple-material junctions. The core-hole excited by the XUV transitions also imparts structural information on to the probed electronic transition. Transient XUV can therefore measure electron and averaged phonon dynamics for each elemental species in a junction. Application to polaron measurement in α-Fe_2O_3, valley-specific scattering in Si, and charge transfer in a nanoscale Ni-TiO_2-Si junction will be discussed

An iterative method to compute the overlap Dirac operator at nonzero chemical potential

The overlap Dirac operator at nonzero quark chemical potential involves the computation of the sign function of a non-Hermitian matrix. In this talk we present an iterative method, first proposed by us in Ref. [1], which allows for an efficient computation of the operator, even on large lattices. The starting point is a Krylov subspace approximation, based on the Arnoldi algorithm, for the evaluation of a generic matrix function. The efficiency of this method is spoiled when the matrix has eigenvalues close to a function discontinuity. To cure this, a small number of critical eigenvectors are added to the Krylov subspace, and two different deflation schemes are proposed in this augmented subspace. The ensuing method is then applied to the sign function of the overlap Dirac operator, for two different lattice sizes. The sign function has a discontinuity along the imaginary axis, and the numerical results show how deflation dramatically improves the efficiency of the method.Comment: 7 pages, talk presented at the XXV International Symposium on Lattice Field Theory, July 30 - August 4 2007, Regensburg, German