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[en] The concepts of the cities we know nowadays, and which we are accustomed to, change at a very rapid pace. The philosophy of their design is also changing. It will base on new standards, entering a completely different, futuristic dimension. This stage is related to changes in the perception of space, location and lack of belonging to definite, national or cultural structures. Cities of the future are cities primarily intelligent, zero-energetic, zero-waste, environmentally sustainable, self-sufficient in terms of both organic food production and symbiosis between the environment and industry. New cities will be able to have new organisational structures—either city states, or, apolitical, jigsaw-like structures that can change their position—like in the case of the city of Artisanopolis, designed as a floating city, close to the land, reminiscent of the legendary Atlantis. This paper is focused on the main issues connected with problems of the contemporary city planning. The purpose of the research was to identify existing technological solutions, whose aim is to use solar energy and urban greenery. The studies were based on literature related to future city development issues and futuristic projects of the architects and city planners. In the paper, the following issues have been verified: futuristic cities and districts, and original bionic buildings, both residential and industrial. The results of the analysis have been presented in a tabular form.
[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 increasing demand for electricity has pushed more effort to focus on renewable energy sources to satisfy the consumer. The renewable energy sources are playing a major role in the generation of electricity. Out of all the renewable energy sources, solar has emerged as one of the best sources of energy since it is clean, inexhaustible and eco-friendly. However, the voltage generated by the solar cell is not sufficient for any consumer load and it is also variable. Therefore, it is necessary to implement DCDC converters for regulating and improving the output voltage of the solar panel. In order to extract the maximum output from the PV (Photovoltaic) panel, a comparative analysis of various MPPT (Maximum Power Point Tracking) algorithms is proposed in this paper. The proposed enhanced adaptive P and O(Perturb and Observe) algorithm is modeled and implemented with a high gain DC-DC converter. The converter investigated in this paper consists of a single power electronic switch (MOSFET) for its operation, which leads to reduction of switching and conduction losses. The proposed converter has less ripple content and a high conversion ratio. A simulation study of the proposed power electronic converter powered by PV source is carried out in MATLAB/SIMULINK and the results are validated using an experimental setup. (author)
[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] Ongoing climate change affects complex and long-lived infrastructures like electricity systems. Particularly for decarbonized electricity systems based on variable renewable energies, there is a variety of impact mechanisms working differently in size and direction. Main impacts for Europe include changes in wind and solar resources, hydro power, cooling water availability for thermoelectric generation and electricity demand. Hence, it is not only important to understand the total effects, i.e., how much welfare may be gained when accounting for climate change impacts in all dimensions, but also to disentangle various effects in terms of their marginal contribution to the potential welfare loss. This paper applies a two-stage modeling framework to assess RCP8.5 climate change impacts on the European electricity system. Thereby, the performance of two electricity system design strategies - one based on no anticipation of climate change and one anticipating impacts of climate change - is studied under a variety of climate change impacts. Impacts on wind and solar resources are found to cause the largest system effects in 2100. Combined climate change impacts increase system costs of a system designed without climate change anticipation due to increased fuel and carbon permit costs. Applying a system design strategy with climate change anticipation increases the cost-optimal share of variable renewable energy based on additional wind offshore capacity in 2100, at a reduction in nuclear, wind onshore and solar PV capacity. Compared to a no anticipation strategy, total system costs are reduced.
[en] There exists a variety of nuclear structure phenomena within the chain of Zr isotopes in the low-excitation regime. While the ground state of 94Zr is spherical in nature, the occurrence of low-lying collective structure has also been observed. The excitation of protons across the Z = 40 sub-shell closure appears to playa dominant role for this collective structure in 94Zr. With the goal of looking for possible competition between proton and neutron excitations in 94Zr, an experiment was carried out at the TRIUMF-ISAC radioactive beam facility. The low-lying states of 94Zr were populated from the β- decay of 94Y. The 8π spectrometer was composed of 20 Compton-suppressed HPGe detectors; details of the experimental setup can be found in earlier literature. Combining the singles and coincidence data, a comprehensive level scheme of 94Zr has been constructed up to Ex ∼ 4.8 MeV, which is very close to the Qβ- value 4.918 MeV. With the revised level lifetimes and the newly found decay branches from the present investigation, the levels could be categorized in terms of proton and neutron excitations. Detailed results obtained from the analysis of the acquired data will be presented
[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] 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.