Search results for "etica."
showing 10 items of 13546 documents
La Repubblica di Platone fra totalitarismo, dissimulazione e utopia
2014
Modelos numéricos para la simulación y el análisis de señales atmosféricas
2015
Los rayos son la principal fuente de radiación de origen natural en la atmósfera terrestre, dado que cada segundo, del orden de un centenar de ellos descargan sobre la superficie de la Tierra, siendo el fenómeno más frecuente en unas regiones que en otras. Dichas descargas emiten la mayor parte de dicha radiación en las bandas ELF y VLF, bandas en la cuales las señales presentan una baja atenuación. La radiación emitida da lugar, en la banda ELF a las resonancias de Schumann y en la banda VLF a campos resonantes en la guía formada por la ionosfera y la superficie de la Tierra. Estas señales nos permiten inferir, por una parte, las propiedades de la ionosfera, y por otra la ubicación donde s…
Algunos problemas sobre holomorfía en dimensión infinita
1996
A theoretical study of the 1B2u and 1B1u vibronic bands in benzene
2000
The two lowest bands, 1B2u and 1B1u, of the electronic spectrum of the benzene molecule have been studied theoretically using a new method to compute vibronic excitation energies and intensities. The complete active space (CAS) self-contained field (SCF) method (with six active π-orbitals) was used to compute harmonic force field for the ground state and the 1B2u and 1B1u electronic states. A linear approximation has been used for the transition dipole as a function of the nuclear displacement coordinates. Derivatives of the transition dipole were computed using a variant of the CASSCF state interaction method. Multiconfigurational second-order perturbation theory (CASPT2) was used to obtai…
Chemical Composition and antimicrobial activity of the essential oils from two species of Thimus growing wild in southern Italy
2009
The volatile constituents of the aerial parts of two samples of Thymus longicaulis C. Presl, collected in Campania and in Sicily, and two samples of Thymus pulegioides L. from the same regions, were extracted by hydrodistillation and analyzed. Considering the four oils together, seventy-eight different compounds were identified: 57 for Thymus longicaulis from Sicily (91.1% of the total oil), 40 for Thymus longicaulis from Campania (91.5% of the oil), 39 for Thymus pulegioides from Sicily (92.5% of the oil) and 29 for Thymus pulegioides from Campania (90.1% of the oil). The composition of the oils is different, although the most abundant components are identical in T. pulegioides. The essent…
Chemical Compositions and Antioxidant Activities of Essential Oils, and Their Combinations, Obtained from Flavedo By-Product of Seven Cultivars of Si…
2022
In this work, seven Citrus aurantium essential oils (EOs) derived from flavedo of cultivars ‘Canaliculata’, ‘Consolei’, ‘Crispifolia’, ‘Fasciata’, ‘Foetifera’, ‘Listata’, and ‘Bizzaria’ were investigated. EOs were also combined in 1:1 (v/v) ratio to identify possible synergism or antagonism of actions. GC-MS analysis was done to investigate Eos’ phytochemical profiles. The antioxidant activity was studied by using a multi-target approach based on FRAP, DPPH, ABTS, and β-carotene bleaching tests. A great difference was observed in EOs’ phytochemical profiles. d-limonene (33.35–89.17%) w…
Genesi geometrica delle volte centriche
1996
Un'analisi completa degli organismi voltati comporta lo studio delle molteplici componenti necessarie alla loro definizione: configurazione geometrica, sistema costruttivo, area storico-geografica di appartenenza, interpretazioni Stilistiche. L’obiettivo di questo studio è indirizzato all' analisi delle volte continue su pianta centrica definibili attraverso le leggi della geometria euclidea. L’indagine si pone all'interno dei confini relativi alla loro configurazione geometrica e il criterio adottato, svincolato da classificazioni di carattere tipologico o stilistico, propone l'identificazione di famiglie geometriche in base alla figura del poligono di base dell'impianto. Si può identifica…
Quantum-chemical determination of Born–Oppenheimer breakdown parameters for rotational constants: the open-shell species CN, CO+ and BO
2013
The quantum-chemical protocol for computing Born-Oppenheimer breakdown corrections to rotational constants in the case of diatomic molecules is extended to open-shell species. The deviation from the Born-Oppenheimer equilibrium rotational constant is obtained by considering three contributions: the adiabatic correction to the equilibrium bond distance, the electronic contribution to the moment of inertia requiring the computation of the rotational g-tensor, and the so-called Dunham correction. Values for the Born-Oppenheimer breakdown parameters of CN, CO+, and BO in their (2)sigma(+) electronic ground states are reported based on coupled-cluster calculations of the involved quantities and …
Buffer-gas-free mass-selective ion centering in Penning traps by simultaneous dipolar excitation of magnetron motion and quadrupolar excitation for i…
2012
A new excitation scheme of the radial ion-motional modes is introduced for Penning-trap ion-cyclotron-resonance experiments. By simultaneous dipolar excitation of the magnetron motion and resonant quadrupolar excitation for the conversion between magnetron motion and cyclotron motion, a mass-selective recentering of the ions of interest is performed while all other (contaminant) ions are ejected from the trap. This new technique does not rely on the application of a buffer gas as presently used [G. Savard, St. Becker, G. Bollen, H.-J. Kluge, R.B. Moore, Th. Otto, L Schweikhard, H. Stolzenberg, U. Wiess, Physics Letters A 158 (1991) 247] and will thus prevent charge-exchange reactions and da…
Ion–Molecule Rate Constants for Reactions of Sulfuric Acid with Acetate and Nitrate Ions
2022
Atmospheric nucleation from precursor gases is a significant source of cloud condensation nuclei in the troposphere and thus can affect the Earth's radiative balance. Sulfuric acid, ammonia, and amines have been identified as key nucleation precursors in the atmosphere. Studies have also shown that atmospheric ions can react with sulfuric acid to form stable clusters in a process referred to as ion-induced nucleation (IIN). IIN follows similar reaction pathways as chemical ionization, which is used to detect and measure nucleation precursors via atmospheric pressure chemical ionization mass spectrometers. The rate at which ions form clusters depends on the ion-molecule rate constant. Howeve…