515 research outputs found
A performance comparison of the contiguous allocation strategies in 3D mesh connected multicomputers
The performance of contiguous allocation strategies can be significantly affected by the distribution of job execution times. In this paper, the performance of the existing contiguous allocation strategies for 3D mesh multicomputers is re-visited in the context of heavy-tailed distributions (e.g., a Bounded Pareto distribution). The strategies are evaluated and compared using simulation experiments for both First-Come-First-Served (FCFS) and Shortest-Service-Demand (SSD) scheduling strategies under a variety of system loads and system sizes. The results show that the performance of the allocation strategies degrades considerably when job execution times follow a heavy-tailed distribution. Moreover, SSD copes much better than FCFS scheduling strategy in the presence of heavy-tailed job execution times. The results also show that the strategies that depend on a list of allocated sub-meshes for both allocation and deallocation have lower allocation overhead and deliver good system performance in terms of average turnaround time and mean system utilization
Повышение энергоэффективности Республики Марий Эл путем внедрения АСКУЭ
Plasma-treated polymers typically show changes of surface morphology as well as modifications in their chemical composition. Both effects are known to have an influence on deposition and adhesion of metal coatings, although the exact mechanisms are not yet understood. Besides high- energy electrons and chemically active species, the generated UV radiation is one major component of plasma surface modification. The energy of ultraviolet photons is sufficiently high to induce bond scissions in polymeric materials, which result in subsequent chemical reactions. In this study, excimer radiation from lasers (e.g. KrF, 248nm) or lamps (e.g. KrCI, 222nm) was used for the formation of polar functional groups on the surface. The treatment was carried out at atmospheric pressure, mostly in air. The chemical and physical properties of the irradiated surface are different compared with untreated areas. The resulting functional groups allow for a spontaneous deposition of molecular thin films from aqueous solutions. In particular, these can be complexes from noble metals. Noble metals catalyze deposition in electroless metallization baths. A process for selective metal deposition on polymers has been developed based on this principle. After deposition, the main issue is the adhesion that can be achieved in the polymer-metal interface. It is determined by chemical or physical interaction between the polymer surface and the adjacent layer, as well as by typographical features
Longitudinal multimodal imaging in mild to moderate Alzheimer disease: a pilot study with memantine
Precision Measurement of the 29Si, 33S, and 36Cl Binding Energies
The binding energies of 29Si, 33S, and 36Cl have been measured with a
relative uncertainty using a flat-crystal spectrometer.
The unique features of these measurements are 1) nearly perfect crystals whose
lattice spacing is known in meters, 2) a highly precise angle scale that is
derived from first principles, and 3) a gamma-ray measurement facility that is
coupled to a high flux reactor with near-core source capability. The binding
energy is obtained by measuring all gamma-rays in a cascade scheme connecting
the capture and ground states. The measurements require the extension of
precision flat-crystal diffraction techniques to the 5 to 6 MeV energy region,
a significant precision measurement challenge. The binding energies determined
from these gamma-ray measurements are consistent with recent highly accurate
atomic mass measurements within a relative uncertainty of .
The gamma-ray measurement uncertainties are the dominant contributors to the
uncertainty of this consistency test. The measured gamma-ray energies are in
agreement with earlier precision gamma-ray measurements.Comment: 13 pages, 4 figure
On the interaction between the island divertor heat fluxes, the scrape-off layer radial electric field and the edge turbulence in Wendelstein 7-X plasmas
The formation of the radial electric field, E-r in the scrape-off layer (SOL) has been experimentally studied for attached divertor conditions in stellarator W7-X. The main objective of this study is to test the validity in a complex three-dimensional (3D) island divertor of simple models, typically developed in tokamaks, relating E-r in the SOL to the sheath potential drop gradient at the target. Additionally, we investigate the effect of the edge E-r shear on the reduction of density fluctuation amplitude, a well-established phenomenon according to the existing bibliography. The main diagnostic for measurements in the SOL is a V-band Doppler reflectometer that can provide the measurement of the E-r and density fluctuations with good spatial resolution. 3D measurements of divertor parameters have been carried out using infrared cameras, with the exponential decay length of the divertor heat flux (lambda(q)) resulting in a suitable proxy for the model-relevant lambda(T), the exponential decay length of the temperature at the divertor. In the investigated attached regimes, it is shown for the first time that the formation of the E-r in the SOL depends on parameters at the divertor, following a E-r proportional to T-e/lambda(q) qualitatively similar to that found in a tokamak. Then, from the analyzed plasmas, the observed E-r shear at the edge is linked to a moderate local reduction of the amplitude of density fluctuations
Characterization of the radial electric field and edge velocity shear in Wendelstein 7-X
In this work we present the first measurements obtained by the V-band Doppler
reflectometer during the second operation phase of Wendelstein 7-X to discuss
the influence in the velocity shear layer and the radial electric field, E,
of several plasma parameters such as magnetic configuration, rotational
transform or degree of detachment. In the first place, we carry out a
systematic characterization of the turbulence rotation velocity profile in
order to describe the influence of density and heating power on E under the
four most frequent magnetic configurations. The E value in the edge is
found to increase with configurations featuring higher , although this
does not apply for the high mirror configuration, KJM. As well, the E value
in the SOL and the velocity shear near the separatrix are found to display a
clear dependence on heating power and density for all configurations. For a
number of relevant cases, these results are assessed by comparing them to
neoclassical predictions obtained from the codes DKES and KNOSOS, finding
generally good agreement with experimental results. Finally, the evolution of
E at the edge is evaluated throughout the island-divertor detachment regime
achieved for the first time in the 2018 campaign. After detachment, E
is reduced both at the SOL and edge, and the plasma column shrinks, with the
shear layer seemingly moving radially inwards from the separatrix.Comment: Sent for publication to Nuclear Fusio
Development of robust metal-supported SOFCs and stack components in EU METSAPP consortium
The potential of MS-SOFCs was demonstrated through the previous EU METSOFC project, which concluded that the development of oxidation resistant novel metal-supported solid oxide fule cell (MS-SOFC) design and stack is the requirement to advance this technology to the next level. The following EU METSAPP project has been executed with an overall aim of developing advanced metal-supported cells and stacks based on a robust, reliable and up-scalable technology. During the project, oxidation resistant nanostructured anodes based on modified SrTiO3 were developed and integrated into MS-SOFCs to enhance their robustness. In addition, the manufacturing of metal-supported cells with different geometries, scalability of the manufacturing process was demonstrated and more than 200 cells with an area of ∼150 cm2 were produced. The electrochemical performance of different cell generations was evaluated and best performance and stability combination was observed with doped SrTiO3 based anode designs. Furthermore, numerical models to understand the corrosion behavior of the MS-SOFCs were developed and validated. Finally, the cost effective concept of coated metal interconnects was developed, which resulted in 90% reduction in Cr evaporation, three times lower Cr2O3 scale thickness and increased lifetime. The possibility of assembling these cells into two radically different stack designs was demonstrated
Recommended from our members
Overview of mathematical approaches used to model bacterial chemotaxis I: the single cell
Mathematical modeling of bacterial chemotaxis systems has been influential and insightful in helping to understand experimental observations. We provide here a comprehensive overview of the range of mathematical approaches used for modeling, within a single bacterium, chemotactic processes caused by changes to external gradients in its environment. Specific areas of the bacterial system which have been studied and modeled are discussed in detail, including the modeling of adaptation in response to attractant gradients, the intracellular phosphorylation cascade, membrane receptor clustering, and spatial modeling of intracellular protein signal transduction. The importance of producing robust models that address adaptation, gain, and sensitivity are also discussed. This review highlights that while mathematical modeling has aided in understanding bacterial chemotaxis on the individual cell scale and guiding experimental design, no single model succeeds in robustly describing all of the basic elements of the cell. We conclude by discussing the importance of this and the future of modeling in this area
Radial electric field and density fluctuations measured by Doppler reflectometry during the post-pellet enhanced confinement phase in W7-X
- …