Results 1 - 10 of 7654
Results 1 - 10 of 7654. Search took: 0.029 seconds
|Sort by: date | relevance|
[en] India has committed to Paris Agreement to generate 30 per cent of its total electricity from renewable Sources by 2030. Roof top solar system will help it to some extent. It is also expected that the distribute; generation (roof top solar PV) at the consumer end will compensate to the acute power shortage in several states. (author)
[en] We present the results of a detailed study of the first accurate 3D ground state interaction potential energy surface (PES) of the Ne–Li2 system by quantum calculations using the coupled-cluster singles and doubles excitation approach with perturbative treatment of triple excitations [CCSD(T)]. The calculations were carried out for the frozen molecular equilibrium geometries and for an extensive range of the remaining two Jacobi coordinates, R and θ, for which a total of about 1976 points is generated for the surface. Mixed basis sets, aug-cc-pVTZ for the Ne atom and cc-pCVTZ for the Li atom, with an additional (3s3p2d2f1g) set of midbond functions are used. The ab initio points on the PES are fitted to a 96-parameter algebraic form with an average absolute error of 0.00000255% and a maximum error less than 0.00888%. The experimental results are compared with our ab initio potential surface calculations. Our PES gives more accurate results along with the experimental data.
[en] The time has come to put an end to the oil nightmare, and to free ourselves from our dependence on the countries that sell it to us. Let's put into new energies the means that we used to devote to the 'deregulation' or privatization of energy. Then they will quickly take over
[fr]Le temps est venu de mettre fin au cauchemar du petrole, et de nous liberer de notre dependance aux pays qui nous le vendent. Mettons dans les energies nouvelles les moyens que nous consacrions jusqu'ici a la 'deregulation' ou la privatisation de l'energie. Alors elles prendront rapidement le relais
[en] Energy is only a utility, it should not lead to feelings or dreams; it is only a question of choosing the most efficient means of heating, cooking, moving, machining, etc., while preserving a pleasant environment. Whether by one means or another, this in itself is of no importance to the citizen. However, if we look at statements and positions, this rationality is often absent; orders of magnitude, availability in space and time, are often forgotten. We move from the pilot experiment to the upheaval of society, forgetting the stages that can be dead ends. We confuse objectives and means by getting enthusiastic about attractive but unrealistic ideas
[fr]L'energie n'est qu'une utilite, elle ne devrait entrainer ni sentiment ni reve; il s'agit seulement de choisir les moyens les plus efficaces pour se chauffer, cuisiner, se deplacer, usiner, etc., tout en preservant un environnement agreable. Que ce soit par une voie ou par une autre, cela n'a pas d'importance en soi pour le citoyen. Pourtant, si l'on regarde les declarations et prises de position, cette rationalite est souvent absente; les ordres de grandeur, les disponibilites dans l'espace et dans le temps, sont souvent oublies. On passe de l'experience pilote au bouleversement de la societe en oubliant les etapes qui peuvent etre des impasses. On confond objectifs et moyens en s'enthousiasmant sur des idees seduisantes mais irrealistes
[en] This article presents experimental analysis on performance augmentation of a single hole cored brick regenerator using turbulence inducers. Experiments were carried out for different velocities with air as the working fluid for both charging and discharging processes of a 455 mm long aluminum regenerator with inner and outer diameters of 26 mm and 40 mm, respectively. Two numbers of turbulence inducers of 1.5 mm diameter and 13 mm long were placed in ten different combinations and the results were compared with the trials wherein no inducers were used. The mean temperature of the cored brick, exit temperature during discharge, ratio of heat transfer rate to pressure drop, and exergetic efficiencies are the characteristics that were used to study the performance of the regenerator. Placement of inducers increased the mean temperature of the regenerator and the ratio of heat transfer rate to pressure drop by about 15% and a maximum of 40%, respectively, during charging. The exit air temperature during discharge exhibited maximum improvement of 18%. Increased exergetic efficiencies of more than 10% and 5% were estimated for charging and discharging, respectively. It was also observed that the addition of inducers does not necessarily result in an increased performance, and some of the combinations in fact deteriorated the performance of the regenerator.
[en] Availability of solar energy being unassured throughout the days, it is necessary to support it by way of storage system for better utility and its wider deployment. The subject work was based on use of phase change material for energy storage and improving its efficiency. The phase change material (PCM) selected was paraffin wax and stored energy was targeted for usage in domestic and process heat applications. Analytical calculations of complete process of charging and discharging of paraffin wax was presented and compared with experimental results. Time required and Number of cycles required for charging and discharging, heat loss calculations were the outcomes of analytical model developed before experimentation. Storage system was integrated with 9.7 m2 Scheffler solar concentrator with cylindrical receiver of capacity 8 L. Receiver was placed at focus of Scheffler solar concentrator where solar rays got concentrated and water got heated up to 900oC in 30 min. The two significant changes made to erstwhile work were use of Scheffler high temperature concentrator and close looping of heated water which enabled shortening of heat exchange cycle as well as heating of water in receiver of Scheffler concentrator. The work opened up further possibility of high temperature heat storage system using other than wax as PCM. Key words: solar energy storage, phase change material, latent heat, sensible heat, charging, discharging
[en] Highlights: • High resolution L1-L2,3M Coster-Kronig spectra in Ar are obtained by electron impact. • Many features are due to the autoionizing decay of neutral doubly excited states. • Energy analysis of ejected electrons ruled out hypothesis of the state origins. - Abstract: The ejected electron spectra between 25 and 56 eV kinetic energy in Ar have been measured at several electron impact energies. When the incident energy is above the Ar 2s ionization potential the peaks due to the L1-L2,3M1 and L1-L2,3M2,3 Coster-Kronig (CK) transitions are expected to occur in this region of kinetic energy, but we observe a series of other narrow structures that overlap and sometime dominate the spectrum due to the CK transitions. These features have been attributed to the autoionizing decay of inner valence doubly excited states to the Ar + ground state.
[en] We have studied the fission parameters of hot neutron-rich thermally fissile and nuclei within the temperature dependent effective field theory motivated relativistic mean field (E-TRMF) formalism by using the recently developed FSUGarnet and IOPB-I parameter sets. The results obtained by these two forces are compared with the results of the well known and widely accepted NL3 parameter set. The excitation energy , shell correction energy , single particle energy for neutrons and protons , level density parameter a, neutron skin thickness ΔR, two neutron separation energy , and asymmetry energy coefficient of these neutron-rich thermally fissile nuclei are calculated at finite temperature. The dependency of level density parameter and other observables on the temperature and the force parameters (interaction Lagrangian) are discussed.
[en] The scientists think on how many photovoltaic (PV) on the vehicle can contribute to the energy supply of mobile systems. Electro mobility with the input of battery appears most probable from wind and solar energy today as the succession technology of the internal combustion engine. This requires a completely new charging network and in the long run, rebuilt possibly in many houses which do not provide today the necessary controlling set up. Also the last rules of power network could be overloaded in unfavourable circumstances, when in the thickly populated cities all may like to load simultaneously. That should be preventive at present scenario before all through the intelligent regulation of the charging phenomenon
[en] The first (namely, inner) fission barriers for even-A N = 152 nuclei have been studied systematically in the framework of macroscopic-microscopic model by means of potential energy surface (PES) calculations in the three-dimensional () deformation space. Their collective properties, such as ground-state deformations, are compared with previous calculations and available observations, showing a consistent trend. In addition, it has been found that the microscopic shell correction energy plays an important role on surviving fission in these N = 152 deformed shell nuclei. The inclusion of non-axial symmetric degree of freedom γ will pull the fission barrier down more significantly with respect to the calculation involving in hexadecapole deformation β 4. Furthermore, the calculated Woods-Saxon (WS) single particle levels indicate that the large microscopic shell correction energies due to low level densities may be responsible for such a reduction on the inner fission barrier. (paper)