33,456 research outputs found
The distance selling directive: consumer champion or complete irrelevance?
This paper investigates the origins, significant content, UK and EU implementation and outcomes of Directive 97/7/EC on distance selling, hereafter referred to as the Distance Selling Directive (DSD). The DSD has been implemented in national legislation by all EU Member States. In the UK this legislation was the Consumer Protection (Distance Selling) Regulations 2000 (SI 2000 No. 2334), hereafter referred to as the CPDSR
Platinum(II), palladium(II), nickel(II), and gold(I) complexes of the “electrospray-friendly” thiolate ligands 4-SC₅H₄N- and 4-SC₆H₄OMe-
The series of platinum(II), palladium(II), and nickel(II) complexes [ML₂(dppe)] [M = Ni, Pd, Pt; L = 4-SC₅H₄N or 4-SC₆H₄OMe; dppe = Ph₂PCH₂CH₂PPh₂] containing pyridine-4-thiolate or 4-methoxybenzenethiolate ligands, together with the corresponding gold(I) complexes [AuL(PPh3)], were prepared and their electrospray ionization mass spectrometric behavior compared with that of the thiophenolate complexes [M(SPh)₂(dppe)] (M = Ni, Pd, Pt) and [Au(SPh)(PPh₃)]. While the pyridine-4-thiolate complexes yielded protonated ions of the type [M + H]+ and [M + 2H]²+ ions in the Ni, Pd, and Pt complexes, an [M + H]+ ion was only observed for the platinum derivative of 4-methoxybenzenethiolate. Other ions, which dominated the spectra of the thiophenolate complexes, were formed by thiolate loss and aggregate formation. The X-ray crystal structure of [Pt(SC₆H₄OMe-4)₂(dppe)] is also reported
Interdisciplinary climate: The case of the first 50 years of British observations in Australia
This paper presents the case for improved interdisciplinarity in climate research in the context of assessing and discussing the caution required when utilizing some types of historical climate data. This is done by a case study examining the reliability of the instruments used for collecting weather data in Australia between 1788 and 1840, as well as the observers themselves, during the British settlement of New South Wales. This period is challenging because the instruments were not uniformly calibrated and were created, repaired, and used by a wide variety of people with skills that frequently remain undocumented. Continuing significant efforts to rescue such early instrumental records of climate are likely to be enhanced by more open, interdisciplinary research that encourages discussion of an apparent dichotomy of view about the quantitative value of early single-instrument data between historians of physics (including museum curators) and climate researchers. © 2012 American Meteorological Society
Yang-Mills Theory on a Cylinder Coupled to Point Particles
We study a model of quantum Yang-Mills theory with a finite number of gauge
invariant degrees of freedom. The gauge field has only a finite number of
degrees of freedom since we assume that space-time is a two dimensional
cylinder. We couple the gauge field to matter, modeled by either one or two
nonrelativistic point particles. These problems can be solved {\it without any
gauge fixing}, by generalizing the canonical quantization methods of
Ref.\[rajeev] to the case including matter. For this, we make use of the
geometry of the space of connections, which has the structure of a Principal
Fiber Bundle with an infinite dimensional fiber. We are able to reduce both
problems to finite dimensional, exactly solvable, quantum mechanics problems.
In the case of one particle, we find that the ground state energy will diverge
in the limit of infinite radius of space, consistent with confinement. In the
case of two particles, this does not happen if they can form a color singlet
bound state (`meson').Comment: 37 pages, UR-1327 ER-40685-77
High-Mobility Few-Layer Graphene Field Effect Transistors Fabricated on Epitaxial Ferroelectric Gate Oxides
The carrier mobility \mu of few-layer graphene (FLG) field-effect transistors
increases ten-fold when the SiO_2 substrate is replaced by single-crystal
epitaxial Pb(Zr_0.2Ti_0.8)O_3 (PZT). In the electron-only regime of the FLG,
\mu reaches 7x10^4 cm^2/Vs at 300K for n = 2.4x10^12/cm^2, 70% of the intrinsic
limit set by longitudinal acoustic (LA) phonons; it increases to 1.4x10^5
cm^2/Vs at low temperature. The temperature-dependent resistivity \rho(T)
reveals a clear signature of LA phonon scattering, yielding a deformation
potential D = 7.8+/-0.5 eV.Comment: 5 pages, 4 figure
Space Shuttle Software Development and Certification
Man-rated software, "software which is in control of systems and environments upon which human life is critically dependent," must be highly reliable. The Space Shuttle Primary Avionics Software System is an excellent example of such a software system. Lessons learn from more than 20 years of effort have identified basic elements that must be present to achieve this high degree of reliability. The elements include rigorous application of appropriate software development processes, use of trusted tools to support those processes, quantitative process management, and defect elimination and prevention. This presentation highlights methods used within the Space Shuttle project and raises questions that must be addressed to provide similar success in a cost effective manner on future long-term projects where key application development tools are COTS rather than internally developed custom application development tool
Approximations for Quantitative Feedback Theory Designs
The computational requirements for obtaining the results summarized in the preceding section were very modest and were easily accomplished using computer-aided control system design software. Of special significance is the ability of the PDT to indicate a loop closure sequence for MIMO QFT designs that employ sequential loop closure. Although discussed as part of a 2 x 2 design, the PDT is obviously applicable to designs with a greater number of inputs and system responses
QFT Multi-Input, Multi-Output Design with Non-Diagonal, Non-Square Compensation Matrices
A technique for obtaining a non-diagonal compensator for the control of a multi-input, multi-output plant is presented. The technique, which uses Quantitative Feedback Theory, provides guaranteed stability and performance robustness in the presence of parametric uncertainty. An example is given involving the lateral-directional control of an uncertain model of a high-performance fighter aircraft in which redundant control effectors are in evidence, i.e. more control effectors than output variables are used
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