Search results for "NELLI"

Nuovi dati sulla biologia alimentare dell’Aquila di Bonelli, Hieraaetus fasciatus, durante il periodo riproduttivo

2001

Aquila di Bonelli (Hieraaetus fasciatus), Status e biologia riproduttiva in Sicilia

2000

Identification of Bioactive Compounds in Polar and Nonpolar Extracts of Araujia sericifera

2017

Abstract Araujia sericifera is a native perennial, climbing laticiferous shrub from South America that is currently naturalized in many other countries. Previous data describe promising properties for A. sericifera, but no systematic study of its bioactive compounds and possible medicinal applications has been conducted to date. In the present study, aerial parts of A. sericifera (leaves, stems, and fruits) were explored by combining GC-MS and NMR spectroscopy analysis for both nonpolar (hexane) and polar (methanol) extracts. The hexanic extracts contained high amounts of pentacyclic triterpenes including two new metabolites, 3-tigloyl germanicol (18) and 3-tigloyl lupeol (19). The methanol…

Dynamics of spin state conversion processes in the solid state

1989

High spin (HS) ⇌ low spin (LS) conversions in transition metal complexes are nonradiative transitions between spin states. In this contribution, we present a study of the temperature and pressure dependence of the HS ⇌ LS intersystem crossing dynamics. For some iron(II) spin-crossover complexes, the rate constants were determined by line shape analysis of57Fe Mossbauer spectra. Their temperature dependence is described by an Arrhenius equation, their pressure dependence is interpreted within absolute rate theory. HS → LS conversion rates at low temperatures were determined from the relaxation of light-induced formation of HS states, monitored by optical spectroscopy. Deviations from a simpl…

Intersystem crossing in Fe(II) coordination compounds

1994

Fe(II) spin-crossover systems can be quantitatively converted from the low-spin (LS) to the high-spin (HS) state well below the thermal transition temperature by irradiating either into the metal-ligand charge transfer or d-d absorption bands, and even in low-spin systems a transient population of the HS state can be achieved. This fact can be made use of to determine HS → LS relaxation rate constants for a wide variety of Fe(II) spin-crossover and low-spin systems. The HS → LS relaxation shows strong deviations from an Arrhenius behaviour, with nearly temperature-independent tunnelling below ∼70 K and a thermally activated process above ∼100 K. The range of more than 12 orders of magnitude…

A Contradiction between Pulsed and Steady-State Studies in the Recombination Kinetics of Close Frenkel Defects in KBr and KCl Crystals

1994

Theoretical study of the kinetics of the correlated annealing of pairs of close (geminate) F-H centers in KCl and KBr crystals controlled by their diffusion and elastic attraction shows that the multi-step (kink) decay in defect concentrations observed more than once in thermostimulated experiments takes place only for very close F-H center pairs which are no further than fourth nearest neighbors. On the other hand, it is demonstrated (both theoretically and experimentally) that such F-H center pairs should be destroyed by the tunneling recombination already at time ≤10 -4 s, i.e. much before beginning of the thermostimulated experiments. Possible explanations of this contradiction are sugg…

Magnetic tunneling junctions with the Heusler compound

2005

Abstract Certain Heusler phases belong to the materials which are discussed as potential half metals. Here, results of tunneling experiments with the full-Heusler alloy Co 2 Cr 0.6 Fe 0.4 Al are presented. The Heusler alloy is used as an electrode of magnetic tunneling junctions. The junctions are deposited by magnetron DC sputtering using shadow mask techniques with AlO x as a barrier and cobalt as counter electrode. Measurements of the magnetoresistive differential conductivity in a temperature range between 4 and 300 K are shown. An analysis of the barrier properties applying the Simmons model to the bias dependent junction conductivity is performed. VSM measurements were carried out to …

On-surface Synthesis of a Chiral Graphene Nanoribbon with Mixed Edge Structure.

2020

Abstract Chiral graphene nanoribbons represent an important class of graphene nanomaterials with varying combinations of armchair and zigzag edges conferring them unique structure‐dependent electronic properties. Here, we describe the on‐surface synthesis of an unprecedented cove‐edge chiral GNR with a benzo‐fused backbone on a Au(111) surface using 2,6‐dibromo‐1,5‐diphenylnaphthalene as precursor. The initial precursor self‐assembly and the formation of the chiral GNRs upon annealing are revealed, along with a relatively small electronic bandgap of approximately 1.6 eV, by scanning tunnelling microscopy and spectroscopy.

Habitat preferences of Bonelli's Eagles Aquila fasciata in Sicily

2012

Capsule For breeding, areas dominated by extensive agricultural and rugged Mediterranean landscapes are preferred; maintenance of habitat heterogeneity and extensive agriculture are key for the conservation of this eagle. Aims To model breeding habitat preferences of Bonelli’s Eagles Aquila fasciata in Sicily, where the last viable population still remains in Italy, in order to identify the most important habitats for conservation. Methods Pairs were monitored between 1990 and 2010. A case-control design through GLMs was used at two spatial scales: landscape and home-range. Variables included topographic, climatic, land-use, road and descriptors of habitat heterogeneity. Information-based c…

On Caretta caretta’s shell: first spatial analysis of micro- and macro-epibionts on the Mediterranean loggerhead sea turtle carapace

2021

The loggerhead sea turtle, Caretta caretta (Linnaeus, 1758), is the most common sea turtle species in the Mediterranean Sea, where it can experience severe anthropogenic impacts. Although C. caretta is known to host more than 200 epibiotic taxa (crustaceans, algae and cyanobacteria), no reports have included a detailed evaluation of the microbial community of its carapace scutes. Thus, this study aimed to determine the diversity and composition of the visible and invisible communities on the carapace scutes of wild loggerhead turtles from the Aeolian Archipelago (Southern Tyrrhenian Sea, Italy) by using a combined approach of morphological/spatial examination and molecular analyses. Altoget…