Search results for " generation."
showing 10 items of 1108 documents
Quantum Ring in a Magnetic Field: High Harmonic Generation and NOT Logic Gate
2020
The effect of a static magnetic field on the high harmonic generation (HHG) from a quantum ring driven by one laser polarized along the x-axis is studied. The spin polarization (Formula presented.) and the temporal emission of the harmonics are studied by varying the intensity of the magnetic field and it is shown how these results have a significant technological impact in computer technology; in fact a boolean algebra can be implemented by assigning 0 and 1 values to low and high pulse intensities of the emitted harmonics and logic gates like the NOT can be created.
Bulky, Dendronized Iridium Complexes and their Photoluminescence
2019
Solution-processed blue emitters are essential for low-cost organic light-emitting diodes (OLEDs) but still face challenges due to their poor color purity, low efficiency and limited operational stability. Herein, by extending the conjugation of ultraviolet-emissive, facial tris(diphenylbenzimidazolyl)iridium (Ir) (fac-(dpbic)3Ir), we introduce two new types of solution-processed emitters, i.e. triisopropylsilylethynyl(TIPSE)-substituted fac-(dpbic)3Ir (2) and fac-(dpbic)3Ir-based polyphenylene dendrimers D1 and D2. The emissions of Ir-complex 2 and the dendrimers were successfully pushed toward a pure and sky blue color, respectively, due to the dominant 3π–π* nature of their emissive exci…
A validated energy model of a solar dish-Stirling system considering the cleanliness of mirrors
2020
Solar systems based on the coupling of parabolic concentrating collectors and thermal engines (i.e. dish-Stirling systems) are among the most efficient generators of solar power currently available. This study focuses on the modelling of functioning data from a 32 kWe dish-Stirling solar plant installed at a facility test site on the University of Palermo campus, in Southern Italy. The proposed model, based on real monitored data, the energy balance of the collector and the partial load efficiency of the Stirling engine, can be used easily to simulate the annual energy production of such systems, making use of the solar radiation database, with the aim of encouraging a greater commercialisa…
L'Analogie chez Aristote
2021
Revue de philosophie dont l’objet est de montrer, d’interroger ou d’évaluer les comparaisons effectives dans les différents champs disciplinaires, Analogia est une publication scientifique annuelle de l’IPC.Chaque numéro réunit un conseil scientifique nouveau chargé de sélectionner les contributions en double aveugle.L’Analogie chez Aristote.Sous la direction d’Emmanuel Brochier.Conseil scientifique :- Katerina Ierodiakonou (Genève – Athènes)- André Laks (Paris)- Benjamin C. Morison (Princeton)- Jean-Luc Solère (Boston)Sommaire :- Présentation, par Emmanuel Brochier, p. 5 ;- Christof Rapp : "Spotting similarities between disparate items" Observations on the use of analogy in Aristotle’s met…
Process analysis of a biomass-based quad-generation plant for combined power, heat, cooling, and synthetic natural gas production
2015
Abstract A new concept for upgrading distributed co-generation plants to quad-generation plants, which combine the production of power, heating, cooling and synthetic natural gas (SNG), is designed and analyzed. Five cases with SNG production ranging from 0% to 100% of total energy outputs are designed to simulate different modes of operation. The quad-generation system is simulated using ASPEN PLUS and described by simulating different portions of the system. This paper also describes the new process, which is of particular interest for improving the total first law efficiency. With this system, it is possible to increase the efficiency of natural resource utilization, minimize the environ…
Efficient energy conversion for cubic third-harmonic generation that is phase matched in KTiOPO(4).
2000
We demonstrate, for the first time to our knowledge, that efficient third-harmonic generation can be achieved with a cubic contribution much larger than the quadratic processes. An energy-conversion efficiency of 2.4% is achieved for cubic third-harmonic generation that is phase matched along the x axis of a KTiOPO(4) crystal by use of a picosecond fundamental laser emitting at 1618 nm. The associated cascading processes are only 10% of the pure cubic interaction, which is very suitable for study of the specific quantum optical correlations. Calculations of the third-harmonic generation conversion efficiency with respect to group-velocity dispersion and to the longitudinal Gaussian beam pro…
A set-up for simultaneous measurement of second harmonic generation and streaming potential and some test applications.
2018
We present a measurement cell that allows simultaneous measurement of second harmonic generation (SHG) and streaming potential (SP) at mineral-water interfaces with flat specimen that are suitable for non-linear optical (NLO) studies. The set-up directly yields SHG data for the interface of interest and can also be used to obtain information concerning the influence of flow on NLO signals from that interface. The streaming potential is at present measured against a reference substrate (PTFE). The properties of this inert reference can be independently determined for the same conditions. With the new cell, for the first time the SHG signal and the SP for flat surfaces have been simultaneousl…
Time evolution of the microwave second-order response of YBaCuO powder
2003
Transient effects in the microwave second-order response of YBaCuO powder are investigated. The time evolution of the second harmonic signal has been measured for about 300 s after the sample had been exposed to variations of the DC magnetic field. We show that in different time scales the transient response has different origin. In the time scale of milliseconds the transient response of samples in the critical state is ascribable to processes of flux redistribution induced by the switching on/off of the microwave field. At longer times, the time evolution of the second harmonic signal can be ascribed to motion of fluxons induced by the variation of the DC magnetic field. In particular, di…
Time evolution of the microwave second-harmonic response of MgB2 superconductor
2003
We report on transient effects in the microwave second-order response of two ceramic MgB2 samples. The time evolution of the second-harmonic signal is investigated for about 500 s after the sample has been exposed to a variation of the dc magnetic field. We suggest that during the first seconds the response is determined by diffusive motion of fluxons, while in the time scale of minutes it is ruled by magnetic relaxation over the surface barrier.
Microwave second-harmonic response of ceramic MgB2 samples
2005
Nonlinear microwave response of different ceramic MgB2 samples has been investigated by the technique of second-harmonic emission. The second-harmonic signal has been investigated as a function of temperature, DC magnetic field and input microwave power. The attention has mainly been devoted to the response at low magnetic fields, where nonlinear processes arising from motion of Abrikosov fluxons are ineffective. The results show that different mechanisms are responsible for the nonlinear response in the different ranges of temperature. At low temperatures, the nonlinear response is due to processes involving weak links. At temperatures close to Tc, a further contribution to the harmonic em…