122,887 research outputs found
A Feasibility Study of Liquid Sterile Insertion
Technique for sterile insertion of liquids into previously sterilized spacecraf
IVOA Recommendation: SAMP - Simple Application Messaging Protocol Version 1.3
SAMP is a messaging protocol that enables astronomy software tools to
interoperate and communicate.
IVOA members have recognised that building a monolithic tool that attempts to
fulfil all the requirements of all users is impractical, and it is a better use
of our limited resources to enable individual tools to work together better.
One element of this is defining common file formats for the exchange of data
between different applications. Another important component is a messaging
system that enables the applications to share data and take advantage of each
other's functionality. SAMP builds on the success of a prior messaging
protocol, PLASTIC, which has been in use since 2006 in over a dozen astronomy
applications and has proven popular with users and developers. It is also
intended to form a framework for more general messaging requirements
What determines self-employment? : a comparative study
This article consists of a comparative study of the incidence of self-employment (SE) between Greece, which has the highest rate of SE in the European Union and the United Kingdom, which has amongst the lowest. Data from the Greek and the UK Labour Force Surveys are used in order to assess how personal attributes of an individual have an impact on the incidence of SE. It is found that common patterns exist between these two countries. In particular, it is found that for both countries, males have greater odds of being self-employed than females, older people have greater odds than younger, individuals employed in the primary and tertiary sectors have greater odds than the ones employed in the secondary, and that individuals with primary or secondary education have greater odds of being self-employed than individuals holding higher degrees. The incidence of SE is also found to differ according to the occupation of the individual. On the other hand, the findings indicate that individuals, residing in London, have greater odds of being self-employed than individuals working outside UK's capital, whereas in Greece the pattern is reversed
Electron spin decoherence of single Nitrogen-Vacancy defects in diamond
We present a theoretical analysis of the electron spin decoherence in single
Nitrogen-Vacancy defects in ultra-pure diamond. The electron spin decoherence
is due to the interactions with Carbon-13 nuclear spins in the diamond lattice.
Our approach takes advantage of the low concentration (1.1%) of Carbon-13 and
their random distribution in the diamond lattice by an algorithmic aggregation
of spins into small, strongly interacting groups. By making use of this
\emph{disjoint cluster} approach, we demonstrate a possibility of non-trival
dynamics of the electron spin that can not be described by a single time
constant. This dependance is caused by a strong coupling between the electron
and few nuclei and results, in particular, in a substantial echo signal even at
microsecond time scales. Our results are in good agreement with recent
experimental observations
Coulomb force effects in low-energy -deuteron scattering
The -proton Coulomb interaction is included in the description of
-deuteron scattering using the screening and renormalization approach
in the framework of momentum-space three-particle equations. The technical
reliability of the method is demonstrated. Large Coulomb-force effects are
found.Comment: To be published in Phys. Rev.
A framework for the forensic investigation of unstructured email relationship data
Our continued reliance on email communications ensures that it remains a major source of evidence during a digital investigation. Emails comprise both structured and unstructured data. Structured data provides qualitative information to the forensics examiner and is typically viewed through existing tools. Unstructured data is more complex as it comprises information associated with social networks, such as relationships within the network, identification of key actors and power relations, and there are currently no standardised tools for its forensic analysis. Moreover, email investigations may involve many hundreds of actors and thousands of messages. This paper posits a framework for the forensic investigation of email data. In particular, it focuses on the triage and analysis of unstructured data to identify key actors and relationships within an email network. This paper demonstrates the applicability of the approach by applying relevant stages of the framework to the Enron email corpus. The paper illustrates the advantage of triaging this data to identify (and discount) actors and potential sources of further evidence. It then applies social network analysis techniques to key actors within the data set. This paper posits that visualisation of unstructured data can greatly aid the examiner in their analysis of evidence discovered during an investigation
Promoting nutrition sensitive and climate smart agriculture through increased use of traditional underutilised species in the Pacific
Poster presented at Tropentag 2014. International Conference on Research on Food Security, Natural Resource Management and Rural Development. "Bridging the Gap between Increasing Knowledge and Decreasing Resources" Prague (Czech Republic) Sep 17-19 2014
A fast and robust approach to long-distance quantum communication with atomic ensembles
Quantum repeaters create long-distance entanglement between quantum systems
while overcoming difficulties such as the attenuation of single photons in a
fiber. Recently, an implementation of a repeater protocol based on single
qubits in atomic ensembles and linear optics has been proposed [Nature 414, 413
(2001)]. Motivated by rapid experimental progress towards implementing that
protocol, here we develop a more efficient scheme compatible with active
purification of arbitrary errors. Using similar resources as the earlier
protocol, our approach intrinsically purifies leakage out of the logical
subspace and all errors within the logical subspace, leading to greatly
improved performance in the presence of experimental inefficiencies. Our
analysis indicates that our scheme could generate approximately one pair per 3
minutes over 1280 km distance with fidelity (F>78%) sufficient to violate
Bell's inequality.Comment: 10 pages, 4 figures, 5 tables (Two appendixes are added to justify
two claims used in the maintext.
The nature of X-ray spectral variability in Seyfert Galaxies
We use a model-independent technique to investigate the nature of the 2-15
keV X-ray spectral variability in four Seyfert galaxies and distinguish between
spectral pivoting and the two-component model for spectral variability. Our
analysis reveals conclusively that the softening of the X-ray continuum with
increasing flux in MCG -6-30-15 and NGC 3516 is a result of summing two
spectral components: a soft varying component (SVC) with spectral shape
independent of flux and a constant hard component (HCC). In contrast, the
spectral variability in NGC 4051 can be well described by simple pivoting of
one component, together with an additional hard constant component. The
spectral variability model for NGC 5506 is ambiguous, due to the smaller range
of fluxes sampled by the data. We investigate the shape of the hard spectral
component in MCG -6-30-15 and find that it appears similar to a pure reflection
spectrum, but requires a large reflected fraction (R>3). We briefly discuss
physical interpretations of the different modes of spectral variability.Comment: Accepted for publication in MNRAS letter
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