Site and query scheduling policies in multicomputer databasesystems

We study run-time issues, such as site allocation and query scheduling policies, in executing read-only queries in a hierarchical, distributed memory, multicomputer system. The particular architecture considered is based on the hypercube interconnection. The data are stored in a base cube, which is controlled by a control cube and host node hierarchy. Input query trees are transformed into operation sequence trees, and the operation sequences become the units of scheduling. These sequences are scheduled dynamically at run-time. Algorithms for dynamic site allocation are provided. Several query scheduling policies that support interquery concurrency are also studied. Average query completion times and initiation delays are obtained for the various policies using simulations     

1D GaAs Detector Arrays for Digital X-ray Imaging

1D imaging arrays of GaAs x-ray detectors are designed, fabricated, and tested. Each array consists of 64 detectors arranged with a pitch of 0.4 mm. In x-ray testing, an almost linear relationship is found between the detector response and the tube current. Zero detector cross coupling is observed in scanning an x-ray beam along any array.     

Seasonal variations in theaflavins,thearubigins, total colour and brightness of Kangra orthodox tea (Camellia sinensis (L) O Kuntze) in Himachal Pradesh

Variations in theaflavins, thearubigins, total colour and brightness of orthodox black tea were studied for four consecutive years (1993–1996) with a view to evaluating the effects of changing weather conditions on the quality of Kangra tea. A degree of withering of 600–650 mg g⁻¹ during the first, second and fourth seasons was optimal for the development of significantly higher brightness and total colour characteristics. The quality of rainy season teas suffered owing to high chlorophyll content and low degree of withering. Hot air circulation through the withering troughs to assist evaporation of leaf moisture increased the brightness and total colour of rainy season teas. High atmospheric demand during the dry season assisted loss of green leaf moisture, but withering and brightness exhibited significant negative correlations with high relative humidity and rainfall. Summer season teas were superior in their total colour and brightness. © 2000 Society of Chemical Industry     

Status of the ion sources developments for the Spiral2 project at GANIL

The SPIRAL 2 facility is now under construction and will deliver either stable or radioactive ion beams. First tests of nickel beam production have been performed at GANIL with a new version of the large capacity oven, and a calcium beam has been produced on the heavy ion low energy beam transport line of SPIRAL 2, installed at LPSC Grenoble. For the production of radioactive beams, several target∕ion-source systems (TISSs) are under development at GANIL as the 2.45 GHz electron cyclotron resonance ion source, the surface ionization source, and the oven prototype for heating the uranium carbide target up to 2000?°C. The existing test bench has been upgraded for these developments and a new one, dedicated for the validation of the TISS before mounting in the production module, is under design. Results and current status of these activities are presented.     

Sharing and caring of eScience data

This commentary reflects on the issues presented in this volume from the perspective of a large eScience project, GEON, whose aim is to promote data integration in the geosciences within the US and abroad. Technical, social, and regulatory challenges accompanying the collection, curation, and sharing of eScience data are discussed. Opportunities and barriers to engaging in international eScience collaborations are highlighted.     

Structural and Luminescent Properties of SiO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>N<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript>(Si) Nanocomposite Films

With a view to creating Si LEDs, the structural and luminescent properties of SiO _x N _y films containing Si nanocrystals in the SiO _x N _y matrix are studied experimentally. It is found that the film structure (nanocrystal size and concentration, the presence of an amorphous phase, etc.) and the spectrum and intensity of photoluminescence (PL) and electroluminescence (EL) are strongly dependent on the Si stoichiometric excess δ and annealing conditions. At δ≈ 10%, unannealed films are amorphous and contain Si clusters of size < 2 nm, as deduced from the TEM and microdiffraction data obtained. Annealing at 800–1000°C for 10–60 min produces Si crystals 3–5 nm in size with a concentration of ≈10¹⁸ cm^?3. The annealed films exhibit room-temperature PL and EL over the wavelength range 400–850 nm with intensity peaks located at 50–60 and 60–70 nm, respectively. The PL and EL spectra are found to be qualitatively similar. This suggests that both the PL and the EL should be associated with the formation of luminescent centers at nanocrystal–matrix interfaces and in boundary regions. However, the two phenomena should differ in the mechanism by which the centers are excited. With the EL, excitation should occur by impact processes due to carrier heating in high electric fields. It is found that as δ increases, so does the proportion of large amorphous Si clusters with a high density of dangling bonds. This enhances nonradiative recombination and suppresses luminescence.     

Effect of industrial contact with penicillin on the immunological reactivity of workers

Immunological examination of women occupied in production of penicillin revealed a decrease in the phagocytic activity of the blood neutrophiles and the bactericidal properties of the skin, an increase in the quantitative composition of the autoflora of the skin and changes in its biochemical properties. Correlation between the changes in the values of the natural non-specific immunity as dependent on the level of the contact with the antibiotic was shown.     

Composition and microstructure of the luminescence-active area in the light-emitting SiO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>N<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript>(Si) nanocomposite layers

Features of formation, the composition, and the mictostructure of the luminescence-active transition region arising in the course of the deposition of the SiO _x N _y (Si) nanocomposite layer with the use of the reactive ion sputtering of the Si target in the O₂ and N₂ atmosphere are studied. The composition and the microstructure of the transition regions are analyzed using the methods of the X-ray photoelectron spectroscopy (XPS) upon the layer-by-layer etching of the composite layers. it is found that the transition regions contain amorphous clusters and nanocrystals of Si as well as such nanoinclusions as Si-Si chains in the oxynitride matrix. The influence of the microstructure on the characteristics of the electroluminescence of nanocomposite layers is revealed.     

Experience in using at a polyclinic the Siberia low-dose digital X-ray unit

Application interactive CLASS software for stimulating productive binocular cooperation based on random-dot patterns and stereograms was used for treating strabismus and amblyopia in 105 children during a standard course of treatment. The children were divided into 3 groups treated by the CLASS alone (1), Class + two other application programs (2), and CLASS + traditional methods. General positive changes (improvement of visual acuity, decrease of eye deviation, etc.) were similar in these 3 groups. Positive effect of CLASS exercises on binocular visual mechanisms was significant. Due to precise evaluation of binocular interaction provided by CLASS, positive changes in binocular cooperation and stereovision were attained in 93% of children.     

Roadmap for the design of a superconducting electron cyclotron resonance ion source for Spiral2

A review of today achieved A∕Q = 3 heavy ions beams is proposed. The daily operation A∕Q = 3 ion beam intensities expected at Spiral2 are at the limit or above best record 3rd generation electron cyclotron resonance ion source (ECRIS) intensities. The necessity to build a new fully superconducting to fulfill these requirements is outlined. A discussion on the volume of the future source is proposed and the minimum value of 12 liters is derived. An analysis of the x-ray absorption superconducting ECRIS is presented based on VENUS experimental data and geometry. This study underlines the necessity to include a complete x-ray study at the time of source conception. The specifications foreseen for the new ECRIS are presented, followed with the roadmap for the design.