Search results for "Ilici"

A Quantitative Model for Alkane Nucleophilicity Based on C−H Bond Structural/Topological Descriptors

2020

A first quantitative model for calculating the nucleophilicity of alkanes is described. A statistical treatment was applied to the analysis of the reactivity of 29 different alkane C−H bonds towards in situ generated metal carbene electrophiles. The correlation of the recently reported experimental reactivity with two different sets of descriptors comprising a total of 86 parameters was studied, resulting in the quantitative descriptor‐based alkane nucleophilicity (QDEAN) model. This model consists of an equation with only six structural/topological descriptors, and reproduces the relative reactivity of the alkane C−H bonds. This reactivity can be calculated from parameters emerging from th…

Seismic and sedimentologic features of Oxfordian-Kimmeridgian syn-rift sediments on the eastern margin of the Lusitanian Basin

1989

Following deposition of widespread middle Oxfordian lacustrine carbonates and evaporites, the Lusitanian Basin was differentiated into a number of sub-basins. The Arruda sub-basin is a half graben basin situated some 30 km north of Lisbon. It accumulated over 2.5 km of Kimmeridgian siliciclastic sediments, and is bounded to the east by the Vila Franca de Xira fault zone. Carbonate deposition persisted over horsts along the fault zone from the Oxfordian to the early Kimmeridgian, and in places to the late Kimmeridgian, and shows a pronounced west-east facies zonation, with higher energy framestones and grainstones accumulating along the exposed western margins. Seismic data indicate a major …

CARATTERIZZAZIONE DELL' INTERFACCIA TRA OSSIDO CONDUTTIVO TRASPARENTE E SILICIO AMORFO IDROGENATO PER APPLICAZIONI IN CELLE SOLARI A FILM SOTTILE

2011

This work is the result of three years of studies during the PhD course in “Applied Physics” at the University of Palermo. The main object of the scientific activity is the electrical characterization and simulation of heterojunctions between transparent conductive oxide (TCO) and hydrogenated amorphous silicon (a-Si:H) for applications in thin film solar cells. The goal of this research is to improve the performance of p-i-n diode hydrogenated amorphous silicon thin film solar cells, in order to define the possible improvement of these prototypes. This PhD work stems from a collaboration between the Department of Physics, University of Palermo, the Institute for Microelectronics and Micros…

The role of the silicatein-alpha interactor silintaphin-1 in biomimetic biomineralization.

2008

Biosilicification in sponges is initiated by formation of proteinaceous filaments, predominantly consisting of silicateins. Silicateins enzymatically catalyze condensation of silica nanospheres, resulting in symmetric skeletal elements (spicules). In order to create tailored biosilica structures in biomimetic approaches it is mandatory to elucidate proteins that are fundamental for the assembly of filaments. Silintaphin-1 is a core component of modularized filaments and also part of a spicule-enfolding layer. It bears no resemblance to other proteins, except for the presence of an interaction domain that is fundamental for its function as scaffold/template. In the presence of silicatein sil…

Facies and facies association of the siliciclastic Brak River and carbonate Gemsbok formations in the Lower Ugab River valley, Namibia, W. Africa

2007

Abstract The Neoproterozoic Zerrissene Turbidite Complex of central-western Namibia comprises five turbiditic units. From the base to the top they are the Zebraputs Formation (greywacke and pelite), Brandberg West Formation (marble and pelite), Brak River Formation (greywacke and pelite with dropstones), Gemsbok River Formation (marble and pelite) and Amis River Formation (greywacke and pelites with rare carbonates and quartz-wacke). In the Lower Ugab River valley, five siliciclastic facies were recognised in the Brak River Formation. These are massive and laminated sandstones, classical turbidites (thick- and thin-bedded), mudrock, rare conglomerate and breccia. For the carbonate Gemsbok R…

Impact of storms on mixed carbonate and siliciclastic shelves: insights from combined diffusive and fluid-flow transport stratigraphic forward model

2004

Abstract A quantitative stratigraphic model of mixed carbonate/siliciclastic continental shelves is presented to investigate the relationships between depositional processes and stratigraphic responses at long‐term, large spatial scales. A diffusion model is combined with a fluid‐flow approach to simulate both long‐term factors, i.e. the processes controlling large‐scale architecture, and short‐term processes, i.e. sediment redistribution by storms. Any net sediment accumulation is the result of the succession of a storm and a fair‐weather period. Sediments are mobilized by waves and advected by low‐frequency currents during storm events. Sediments are then reworked and redistributed downsl…

Weak aurophilic interactions in a series of Au(III) double salts.

2015

In this work, several new examples of rare AuIII⋯AuIII aurophilic contacts are reported. A series of gold(III) double salts and complexes, viz. [AuX2(L)][AuX4] (L = 2,2′-bipyridyl, X = Cl 1, Br 2; L = 2,2′-bipyrimidine, X = Cl 3, Br 4; L = 2,2′-dipyridylamine, X = Cl 5, Br 6), [AuX3(biq)] (biq = 2,2′-biquinoline, X = Cl 7, Br 8), [LH][AuX4] (L = 2,2′-bipyridyl, X = Cl 9; L = 2,2′-bipyrimidine, X = Cl 12; L = 2,2′-dipyridylamine, X = Cl 14, Br 15; L = 2,2′-biquinoline, X = Cl 17, Br 18), [AuBr2(bpy)]2[AuBr4][AuBr2] 10, [AuCl2(bpm)][AuCl2] 11, (bpmH)2[AuBr4][AuBr2] 13, and (dpaH)[AuBr2] 16 (1, 2, and 7 were reported earlier) was synthesized by coordination of a particular ligand to the AuIII …

Inter-relazioni tra pools di C organico e gruppi funzionali della sostanza organica in un suolo a diversa gestione agronomica

2013

Lavorazioni del suolo e rotazioni colturali giocano un ruolo chiave nell’influenzare sia la quantità sia la qualità della sostanza organica del suolo (SOM). Mentre diversi studi sono stati condotti per valutare gli effetti di tali fattori agronomici sui pools di C organico, anche lungo i profili di suolo, pochi altri hanno investigato anche le relazioni tra i diversi pools di C organico e i gruppi funzionali della SOM. Obiettivi del presente lavoro sono stati quelli di i) valutare gli effetti della lavorazione del suolo e delle rotazioni colturali sui diversi pools di C organico e ii) di investigare le relazioni intercorrenti tra tali pools e i gruppi funzionali della SOM. I campioni di suo…

Genetic diversity in Sicilian Population of Quercus ilex (Fagaceae)

2013

La classe Quercetea ilicis in Sicilia.

2008

On the basis of literature data and numerous unpublished relevès, a syntaxonomic revision of Quercetea ilicis class in Sicily is given. The surveyed associations are represented by evergreen, deciduous o mixed plant communities forming shrubland, maquis, bushland and woodland. They are communities dominated by sclerophylls or deciduous trees, widespread from the shoreline up to 1400 (1600) m of altitude, within the bioclimatic belts between the inframediterranean dry lower one and the mesomediterranean subhumid-humid one, extending to the supramediterranean belt. The study, regarding all the Sicilian territory including the neighboring islets, was carried out through the elaboration of syno…