Search results for "potential [nucleon nucleon]"

Application of SQMFF Vibrational Calculations to Transition States:  DFT and ab Initio Study of the Kinetics of Methyl Azide and Ethyl Azide Thermoly…

1998

DFT including nonlocal corrections and ab initio calculations at MP2 and MP4 levels of theory have been performed in order to provide information concerning the mechanism of the rate limiting step of the thermal decomposition of methyl azide and ethyl azide. The chemically interesting points of the ground-state potential energy surface have been fully optimized, and a detailed normal-mode analysis for the reagents and the transition states is presented. The well-established scaled quantum mechanical force field method has been used to obtain reliable vibrational frequencies for these molecular structures. The force fields of transition states have been modified by using the scale factors co…

A theory ofnonverticaltriplet energy transfer in terms of accurate potential energy surfaces: The transfer reaction from π,π* triplet donors to 1,3,5…

2004

Triplet energy transfer (TET) from aromatic donors to 1,3,5,7-cyclooctatetraene (COT) is an extreme case of "nonvertical" behavior, where the transfer rate for low-energy donors is considerably faster than that predicted for a thermally activated (Arrhenius) process. To explain the anomalous TET of COT and other molecules, a new theoretical model based on transition state theory for nonadiabatic processes is proposed here, which makes use of the adiabatic potential energy surfaces (PES) of reactants and products, as computed from high-level quantum mechanical methods, and a nonadiabatic transfer rate constant. It is shown that the rate of transfer depends on a geometrical distortion paramet…

Argon broadening of the 13CO R(0) and R(7) transitions in the fundamental band at temperatures between 80 and 297K: comparison between experiment and…

2003

We present measurements of Ar-broadening parameters for the R(0) and R(7) lines in the fundamental band of13CO at eight temperatures from 80 to 297 K. The broadening parameters are determined by simultaneous least-squares fitting of spectra recorded using a frequency stabilized diode laser spectrometer. The comparison of the broadening parameter values for R(7) derived at room temperature and different pressures from different line profiles shows that an empirical line profile, which takes into account narrowing effects (Dicke narrowing and absorber speed dependence) but neglects any correlation between collisions, is able to describe the observed lines with constant values of the narrowing…

Breeding success and mate retention in birds: a meta-analysis

2002

Several hypotheses about the adaptive value of divorce in birds predict a positive effect of breeding success on mate retention. Although some studies have provided direct support for this prediction, others have failed to demonstrate any significant influence of breeding success on mate retention. To date, no one has investigated the overall empirical evidence for such a relationship. We used a meta-analysis of published results to investigate whether the rate of divorce between consecutive breeding seasons differed between successful and unsuccessful breeders among monogamous bird species. The analysis was based on 38 studies involving 35 different species. The mean weighted effect size, …

Explicitly Correlated Electrons in Molecules

2011

Experimental Evaluation of the Performance of a Three-Phase Five-Level Cascaded H-Bridge Inverter by Means FPGA-Based Control Board for Grid Connecte…

2018

Over the last decades, plants devoted to the generation of green energy significantly increased their number, together with the demand of same electrical energy, also stored in battery systems. This fact produced the growth of energy conversion systems with advanced performances with respect to the traditional ones. In this circumstance, multilevel converters play a significant role for their great advantages in performances, flexibility, fault-tolerability, employment of renewable energy sources and storage systems and finally yet importantly reduced filter requirements. In this context, this paper faces the performance of a cascaded H-bridge 5 level inverter in terms of harmonic distortio…

Techno-economic evaluation of PV based institutional smart micro-grid under energy pricing dynamics

2020

Abstract The solar photovoltaic (PV) system with battery energy storage have a lot of potential to provide reliable and cost-effective electricity and to contribute in micro-grid operation. However, the operational performance of such type of micro-grid system depends on many factors (e.g. techno-economic sizing, energy management among the sources, market energy prices dynamics, energy dispatch strategies, etc.). In this paper, a typical Indian institutional energy system has considered for techno-economic performance evaluation for operating as a smart micro-grid under market energy pricing dynamics. The institutional energy system has integrated PV, battery storage and DG for operating a…

On the modelling of an Acid/Base Flow Battery: An innovative electrical energy storage device based on pH and salinity gradients

2020

Abstract Electrical energy storage can enhance the efficiency in the use of fluctuating renewable sources, e.g. solar and wind energy. The Acid/Base Flow Battery is an innovative and sustainable process to store electrical energy in the form of pH and salinity gradients via electrodialytic reversible techniques. Two electromembrane processes are involved: Bipolar Membrane Electrodialysis during the charge phase and its opposite, Bipolar Membrane Reverse Electrodialysis, during the discharge phase. For the first time, the present work aims at predicting the performance of this energy storage device via the development of a dynamic mathematical model based on a multi-scale approach with distr…

Verso una dimensione narrativa delle mappe

2021

Tra il pensiero e la costruzione dell’architettura il disegno ha un ruolo baricentrico per connettere i diversi protagonisti di una realizzazione e per coinvolgere la collettività facendo percepire inedite prospettive. La scrittura si rivela utile per esplicitare ciò che nella grafica è sotteso e per stabilire un ordine nuovo nel ragionamento progettuale. I rapporti fra segni e significati si moltiplicano nei sistemi informativi recenti in cui si ha la sensazione di poter dire moltissimo (dati numerici e spaziali) ma a volte sfugge quella sintesi indispensabile per una interpretazione concreta, finalizzata alla costruzione di possibili esperienze fisiche. Per l’esplorazione dell’uso di dive…

An ab initio potential energy surface for the C2H2-N2 system

2012

International audience; An ab initio potential energy surface determined at the CCSD(T) level of theory is presented for the van der Waals complex C2H2-N2. Additional calculations performed with the HF- and DFT-SAPT methods compare well with the CCSD(T) results and allow a better understanding of the main features of this interaction potential surface. An expansion of this surface over spherical harmonics has also been performed. The global energy minimum of the complex is obtained for the linear conformation. The T conformations are the least attractive. Such characteristics mainly arise because of the variation, in sign and in absolute value of the electrostatic energy between all these c…