Search results for "SPEED"
showing 10 items of 876 documents
Terahertz electrical writing speed in an antiferromagnetic memory
2018
The speed of writing of state-of-the-art ferromagnetic memories is physically limited by an intrinsic gigahertz threshold. Recently, realization of memory devices based on antiferromagnets, in which spin directions periodically alternate from one atomic lattice site to the next has moved research in an alternative direction. We experimentally demonstrate at room temperature that the speed of reversible electrical writing in a memory device can be scaled up to terahertz using an antiferromagnet. A current-induced spin-torque mechanism is responsible for the switching in our memory devices throughout the 12-order-of-magnitude range of writing speeds from hertz to terahertz. Our work opens the…
Speed control of double-sided linear induction motors for automated manufacturing systems
2014
The double-sided linear induction motor (DLIM) is acquiring a significant relevance in the application of automated manufacturing systems. For this purpose, the modeling, simulation and determination of the parameters of a double-sided linear induction motor is presented in this paper. Furthermore, the DLIM constant voltage/frequency speed control system for this application is here described. In order to verify the performance of the proposed system, a suitable test bench for the DLIM motor is set-up. From the good agreement shown by the comparison between measured and simulated results, it can be stated that the DLIM model and the speed control system is successfully validated. © 2014 IEE…
Volumetric properties, viscosities and refractive indices of binary liquid mixtures of tetrafluoroborate-based ionic liquids with methanol at several…
2015
Abstract Densities, speeds of sound, viscosities and refractive indices of two binary systems 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] + methanol and 1-ethyl-3-methylimidazolium tetrafluoroborate [emim][BF4] + methanol, as well as of all pure components, have been measured covering the whole range of compositions at T = (278.15 to 318.15) K and p = 101 kPa. From this data, excess molar volumes, excess isentropic compressibilities, viscosity deviations and refractive index deviations were calculated and fitted to extended versions of the Redlich–Kister equation. Estimated coefficients of these equations taking into account the dependence on composition and temperature simult…
Artificial Intelligence + Distributed Systems = Agents
2009
The connection with Wirth’s book goes beyond the title, albeit confining the area to modern Artificial Intelligence (AI). Whereas thirty years ago, to devise effective programs, it became necessary to enhance the classical algorithmic framework with approaches applied to limited and focused subdomains, in the context of broad-band technology and semantic web, applications - running in open, heterogeneous, dynamic and uncertain environments-current paradigms are not enough, because of the shift from programs to processes. Beside the structure as position paper, to give more weight to some basic assertions, results of recent research are abridged and commented upon in line with new paradigms.…
A grid ant colony algorithm for the orienteering problem
2005
In this paper we propose a distributed ant colony algorithm to solve large scale orienteering problem instances. Our approach is based on a multi-colony strategy where each colony works in an independent portion (cluster) in the original graph. This results in no need for communicating pheromones information among colonies and in increasing speedup. We have implemented our algorithm as a .NET Web services infrastructure following a grid computing philosophy and we provide some promising experimental results to show the feasibility and effectiveness of our approach
Comparative study of modelling the thermal efficiency of a novel straight through evacuated tube collector with MLR, SVR, BP and RBF methods
2021
Abstract Data-based methods are useful for accurate modelling of solar thermal systems. In this work, several artificial neural network (ANN) techniques are proposed to predict the thermal performance of an all-glass straight through evacuated tube solar collector. These are compared to support vector regression analysis. Extensive experimental data sets were collected for training the ANN models. Solar radiation intensity, ambient temperature, wind speed, mass flow rate and collector inlet temperature were selected as the input layer to predict the thermal efficiency of the solar collector. The prediction precision of the ANN models was compared to the multiple linear regression and suppor…
Researches on Grain Harvesting Machines
1970
The purpose of the paper is to present some researches made on the mechanisms of the combine for cutting, feeding and threshing. There are presented the floating cutter bar, the combine with a spike-tooth cylinder and rotary separation, the combine with dual threshing and separating rotors.
 Some of the adjustments are made on the finger sensors for cutter bar. One of the most important adjustment is that made in order to reduce harvest loss. Forward speed is one of the main factor in optimizing the performance of a combine harvester. The method used in the paper is that of direct observing and measuring made on different component parts of combines.
On the Effect of Slotted Blades on Savonius Wind Generator Performances by CFD Analysis
2012
In this paper a new bucket configuration for Savonius wind generator is proposed. With the aim to increase the effect of the overlap ratio RS on the wind turbine performances and to increase the amount of lift force able to produce torque and power, slotted blades are investigated by means of the Computational Fluid Dynamics analysis. The numerical analyses are performed by Comsol Multiphysics® and the results obtained for a Savonius wind turbine with overlap only are compared to numerical and experimental benchmarks. Parametric analyses are performed, for fixed overlap ratio, by varying the slot angle β and the results show that for low angle β the Savonius rotor exploits improved performa…
Estimation of annual energy output of a wind turbine using wind speed probability distribution
2016
In this work, annual energy output of a variable speed wind turbine is analyzed using annual Weibull wind speed probability distribution function. The power coefficient variation with tip speed ratio in torque control region as well as pitch angle variation for maximum power output from wind turbine are analyzed for identifying control system parameters. The wind turbine power output and variation of power coefficient with tip speed ratio as well as pitch angle are examined / reported using annual Weibull distribution function. Finally the variation of the estimated annual energy output of the given wind turbine with the mean wind speed is presented.
Study of the dynamics of biomolecules by high speed atomic force microscopy and surface enhanced Raman spectroscopy
2015
This thesis focuses on the coupling of High–Speed Atomic Force Microscopy (HS-AFM) and Surface Enhanced Raman Spectroscopy (SERS) for biomolecule analysis. We have designed a fabrication protocol to manufacture “SERS-active” substrates. The efficacy of gold, silver and gold-silver bimetallic crystalline nanoparticle substrates were evaluated. We have investigated the impact of optical and morphological features of the substrates on Raman signal intensity by analyzing well-known samples such as bipyridine ethylene and methylene blue molecules. We took an interest in three distinct biological problematics with HS-AFM and SERS analyses. First, we have detected the chemical signature of cytochr…