On the Easy Use of Scientific Computing Services for Large Scale Linear Algebra and Parallel Decision Making with the P-Grade Portal

Scientific research is becoming increasingly dependent on the large-scale analysis of data using distributed computing infrastructures (Grid, cloud, GPU, etc.). Scientific computing (Petitet et al. 1999) aims at constructing mathematical models and numerical solution techniques for solving problems arising in science and engineering. In this paper, we describe the services of an integrated portal based on the P-Grade (Parallel Grid Run-time and Application Development Environment) portal (http://www.p-grade.hu) that enables the solution of large-scale linear systems of equations using direct solvers, makes easier the use of parallel block iterative algorithm and provides an interface for parallel decision making algorithms. The ultimate goal is to develop a single sign on integrated multi-service environment providing an easy access to different kind of mathematical calculations and algorithms to be performed on hybrid distributed computing infrastructures combining the benefits of large clusters, Grid or cloud, when needed.     

Characterization of magnetic materials using a scanning microwave microprobe

We investigated the electromagnetic properties of metals of iron, nickel, cobalt, aluminum, gold, copper, silver, and permalloy thin films on SiO(2) substrates using a near-field microwave microprobe. The electromagnetic properties of metal sheets were estimated by measuring the microwave reflection coefficient S(11) and compared with the theoretical values. We observed the hysteresis behavior of permalloy thin films on SiO(2) substrates using a near-field scanning microwave microprobes (NSMM) system. Experimental results are in good agreement with the theoretical model of transmission theory. In order to better characterize the electromagnetic properties of metals and magnetic metals instead of the usual method, we take advantage of the noncontact microprobing evaluation capabilities using a near-field microwave.     

Megawatt low-temperature DC plasma generator with divergent channels of gas-discharge tract

We have developed and studied a new effective megawatt double-unit generator of low-temperature argon plasma, which belongs to the class of dc plasmatrons and comprises the cathode and anode units with divergent gas-discharge channels. The generator has an efficiency of about 80–85% and ensures a long working life at operating currents up to 4000 A.     

Simulating the effects of climate change,economic and urban planning scenarios on urban runoff patterns of a metropolitan region

Urban development and climate change are expected to have significant effects on urban stormwater runoff. In this study, the Dynamic Urban Water Simulation Model (DUWSiM) is applied to Dublin, Ireland, to explore urban runoff patterns under varying urban growth and climate scenarios. Results show that annual urban runoff could decrease by 3.0% from climate change and monthly runoff could increase by 30% in winter and decrease by 28% in summer. Results also indicate that urban growth could increase annual runoff by up to 15%. The combined effect of climatic and land-use change generated runoff may potentially increase annual totals from between 2.9% to 21%. Monthly changes in runoff totals could increase by up to 57%. Accommodating these variations in runoff between the scenarios, flexible decentralised systems such as green roofs and pervious pavements, have a vital role in increasing the adaptability and long term sustainability of water infrastructure.     

Characterization of the field-effect conductivity distribution in pentacene thin-film transistors by a near-field scanning microwave microscope

Direct probing of the conductivity distribution in organic materials is motivated by the need to obtain a deeper understanding of carrier behavior in organic thin-film transistors (OTFT), organic electro-luminescent devices, organic photoconductors, and organic biosensors. Here we used a near-field scanning microwave microscope to visualize conductivity profiles in OTFT channel. Applying this technique to pentacene field-effect transistors has revealed changes of the conductivity distribution in the channel arising from the development and exhaustion of an accumulated charge region. The electric field profiles, the complementary image of conductivity profiles, which are visualized by using an optical second harmonic generation method, support the results. We anticipate that direct observation by this microwave method will find wide application in measurement of carrier conductivity in organic and nonorganic materials.     

Improving the concept of an asynchronous cyclotron

The main results from improving the concept of an asynchronous cyclotron, the latest version of which has been dubbed a variable-phase asynchronous cyclotron, are presented. Its characteristics are considered using the example of a six-cavity scheme. Its advantages are shown for the multistage acceleration of ultra-high-power proton beams with energies of 2–1000 MeV and continuous currents of up to hundreds of milliamperes over ordinary isochronous and superconducting versions of cyclotrons with separated orbits. The problems of the beam halo are also discussed, and easier possibilities of obtaining spherical bunches for reducing the particle losses are shown. The cost of creating such an accelerator is estimated, and the main relationships for the preliminary selection of its calculation parameters are presented.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 14–23.Original Russian Text Copyright ¢ 2004 by Tumanyan, Sargsyan, Nikogosyan.     

EU-EAEU dilemma of Armenia: Does science support politics?

Scientometrics - On January 1, 2015, the Republic of Armenia joined the (Russian-led) Eurasian Economic Union (EAEU) and actually refrained from entering into the alternative Association Agreement...