Dictionary-based order-preserving string compression

As no database exists without indexes, no index implementation exists without order-preserving key compression, in particular, without prefix and tail compression. However, despite the great potentials of making indexes smaller and faster, application of general compression methods to ordered data sets has advanced very little. This paper demonstrates that the fast dictionary-based methods can be applied to order-preserving compression almost with the same freedom as in the general case. The proposed new technology has the same speed and a compression rate only marginally lower than the traditional order-indifferent dictionary encoding. Procedures for encoding and generating the encode tables are described covering such order-related features as ordered data set restrictions, sensitivity and insensitivity to a character position, and one-symbol encoding of each frequent trailing character sequence. The experimental results presented demonstrate five-folded compression on real-life data sets and twelve-folded compression on Wisconsin benchmark text fields. Edited by M.T. Ozsu. Received 1 February 1995 / Accepted 1 November 1995     

Aging,non-ergodicity,and lévy statistics for blinking nanocrystals

We briefly review phenomenological properties of the intermittency behavior of blinking nanocrystals (i.e., quantum dots). Special emphasis is given to the properties of intensity correlation function that exhibit behaviors mentioned in the title. We discuss models which can be used to explain the strange kinetics of the blinking nanocrystals.     

Surface Composition and Imprint in CSD-Based PZT Films

Reports on PZT films often suggest the contradicting presence of Pb-deficient pyrochlore (Py) and a Pb-rich layer on the surface. We show that standard Ar⁺ ion sputtering X-ray photoelectron spectroscopy (XPS) depth profiles of PZT films artificially exhibit a Pb-rich surface, independent of actual Pb content of the chemical solution deposition solution. However angle-resolved XPS measurements reveal that films derived from solutions with 10% Pb excess, which give rise to Py surface grains, actually have the expected Pb-deficient surface layer. Alternatively, films derived from solutions with 30% Pb excess are Py free and have Pb-rich surface layer. The Pb-rich films show an increased imprint effect with increasing Pb content.     

A new evaluation procedure for the butt-joint test of adhesive technology: Determination of the complete set of linear elastic constants

Simple analytical formulae have been reported in literature to extract basic elastic material properties of adhesives subjected to tensile loading. The assumptions and simplifications of classical evaluation procedures may result in a remarkable error depending on the investigated material combination. This work proposes a new evaluation procedure for the butt-joint test of adhesive technology. The main idea is to determine the deformed shape of the adhesive layer and to relate the deformation, i.e. contraction and elongation, to a unique set of Young's modulus and Poisson's ratio. A numerical parameter study for different combinations of adherend/adhesive materials and butt-joint geometries has been performed to investigate the influence of these parameters on the adhesive deformation. Comprehensive diagrams are derived which relate the deformation of the adhesive layer to the complete set of linear elastic constants.     

Standardization of control of the content of ferrite phase in chromium-nickel austenitic and austenitic-ferritic steels by magnetic method

Results of studies used as a base for a magnetic method of determination of the content of ferrite phase (CFP) in chromium-nickel steels of austenitic and austenitic-ferritic classes with various chemical compositions are presented and standardization of the method is described. Data on the chemical composition and magnetic properties of ferrite phases depending on the composition of the steels are used for substantiating a unit of measurement, i.e., “1% CFP,” when developing a standard “method of magnetic saturation” for measuring the CFP. The process of centrifugal casting is used for fabricating standard CFP specimens for calibrating and checking the equipment for measuring CFP (volume and local ferritometers used in Russia and in other countries). It is reported that the International Institute for Welding (IIW) has checked the Russian standard specimens and it is possible to adapt the Russian magnetic method of CFP control to international standards. The possibility of agreement between the computational and metallographic methods of determination of CFP and the magnetic method is substantiated. A list of the main regulatory documents that stipulate the use of TsNIITMASh developments in the field of magnetic ferritometry is presented. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 53–59, July, 2006.     

Magnetohydrodynamic instability in annular linear induction pump: Part II. Suppression of instability by phase shift

In the previous work, the authors showed some detailed aspects of the magnetohydrodynamic instability arising in an annular linear induction pump: the instability is accompanied with a low frequency pressure pulsation in the range of 0–10 Hz when the magnetic Reynolds number is larger than unity; the low frequency pressure pulsation is produced by the sodium vortices that come from some azimuthal non-uniformity of the applied magnetic field or of the sodium inlet velocity. In the present work, an experiment and a numerical analysis are carried out to verify the pump winding phase shift that is expected as an effective way to suppress the instability. The experimental data shows that the phase shift suppresses the instability unless the slip value is so high, but brings about a decrease of the developed pressure. The numerical results indicate that the phase shift causes a local decrease of the electromagnetic force, which results in the suppression of the instability and the decrease of the developed pressure. In addition, it is exhibited that the intensity of the double-supply-frequency pressure pulsation is in nearly the same level in the case with and without the phase shift.     

DNA-enabled self-assembly of plasmonic nanoclusters

DNA nanotechnology provides a versatile foundation for the chemical assembly of nanostructures. Plasmonic nanoparticle assemblies are of particular interest because they can be tailored to exhibit a broad range of electromagnetic phenomena. In this Letter, we report the assembly of DNA-functionalized nanoparticles into heteropentamer clusters, which consist of a smaller gold sphere surrounded by a ring of four larger spheres. Magnetic and Fano-like resonances are observed in individual clusters. The DNA plays a dual role: it selectively assembles the clusters in solution and functions as an insulating spacer between the conductive nanoparticles. These particle assemblies can be generalized to a new class of DNA-enabled plasmonic heterostructures that comprise various active and passive materials and other forms of DNA scaffolding.