Search results for "character"
showing 10 items of 2956 documents
On Non-Gaussian limiting laws for certain statistics of Wigner Matrices
2013
This paper is a continuation of our papers [12-14] in which the limiting laws of fluctuations were found for the linear eigenvalue statistics Tr j(M(n)) and for the normalized matrix elements √n̅jjj(M(n)) of differentiable functions of real symmetric Wigner matrices M(n) as n →∞. Here we consider another spectral characteristic of Wigner matrices, xnA [j] = Tr j(M(n))A(n), where {A(n)}∞n=1 is a certain sequence of non-random matrices. We show first that if M(n) belongs to the Gaussian Orthogonal Ensemble, then xnA [j] satisfies the Central Limit Theorem. Then we consider Wigner matrices with i.i.d. entries possessing the entire characteristic function and find the limiting probability law f…
Vitamins in wine: Which, what for, and how much?
2021
Vitamins are essential compounds to yeasts, and notably in winemaking contexts. Vitamins are involved in numerous yeast metabolic pathways, including those of amino acids, fatty acids, and alcohols, which suggests their notable implication in fermentation courses, as well as in the development of aromatic compounds in wines. Although they are major components in the course of those microbial processes, their significance and impact have not been extensively studied in the context of winemaking and wine products, as most of the studies focusing on the subject in the past decades have relied on relatively insensitive and imprecise analytical methods. Therefore, this review provides an extensi…
Interspecific territoriality in Calopteryx damselflies: the role of secondary sexual characters
2006
Interspecific territoriality is usually interpreted to result from interspecific interference competition, although it may also originate from mistaken species recognition. In the latter case, it may be based on similarity of secondary sexual characters. In the damselfly Calopteryx splendens, males have pigmented wing spots as a sexual character, and males with the largest spots resemble males of another species, Calopteryx virgo. Probably because of this resemblance, C. virgo males are more aggressive towards large- than small-spotted C. splendens males. We examined whether wing spot size of C. splendens males affects territorial interactions between the species. In a removal experiment, t…
INNOVAZIONE DEI MATERIALI NATURALI: TERRA E NANOTUBI DI ARGILLA PER UNA SFIDA SOSTENIBILE
2019
All’interno del dibattito culturale che vede la questione ambientale come prioritaria e con riferimento a studi e ricerche che negli ultimi anni hanno promosso materiali compositi a base di terra cruda, gli Autori, consapevoli della necessità che il rapporto fra Progetto e Materia debba assumere una nuova centralità supportato dalle specificità della Tecnologia dell’Architettura, illustrano le risultanze di una sperimentazione che ha l’obiettivo di migliorare le prestazioni della terra cruda con l’apporto delle nanotecnologie, sviluppando un ‘nuovo materiale’ con una ridotta embodied energy e una ridotta quantità di emissioni di CO2 in atmosfera.
Meeting Apart: Woody Allen's Characters, Films and Spectators
2007
An analysis of the relationships between Woody Allen's films (from "Take the Money and Run", 1969, to "Anything Else", 2003) and their spectators, starting frim a definition of the public image of the filmmaker then focusing on the film persona and the way the films represent authorial figures and the paradoxical meeting between film and spectator(s).
PrVO$_4$ under High Pressure: Effects on Structural, Optical and Electrical Properties
2020
In pursue of a systematic characterization of rare-earth vanadates under compression, in this work we present a multifaceted study of the phase behavior of zircon-type orthovanadate PrVO$_4$ under high pressure conditions, up until 24 GPa. We have found that PrVO$_4$ undergoes a zircon to monazite transition at around 6 GPa, confirming previous results found by Raman experiments. A second transition takes place above 14 GPa, to a BaWO$_4$-I--type structure. The zircon to monazite structural sequence is an irreversible first-order transition, accompanied by a volume collapse of about 9.6%. Monazite phase is thus a metastable polymorph of PrVO$_4$. The monazite-BaWO$_4$-II transition is found…
Performance improvement of a Savonius water rotor with novel blade shapes
2021
Abstract Savonius water rotor is a prominent drag based turbine able to extract energy available in flowing water with low velocity like river streams, tidal currents or other man made water canals. However, in view of its low performance, an enhanced design of the rotor blades is necessary to better its efficiency. Therefore, the present study aims to improve the efficiency of Savonius rotor by changing the blade design. Different blade shapes were investigated numerically using computational fluid dynamics (CFD). Using conventional design, the peak power coefficient was found to be 0.166 at tip-speed ratio of 0.78. However, the peak power coefficient reaches 0.184 using the optimal blade …
Effect of mechanical stirring and temperature on dynamic hydrothermal synthesis of titanate nanotubes
2017
Abstract In the late century, it has been clearly demonstrated that titanate nanotubes (TNTs) are attractive nanomaterials with various potential applications due to their interesting properties. In this work, an essential reaction parameter, rarely considered in the literature, has been studied: stirring during hydrothermal synthesis. For this purpose, an intermittent mechanical stirring, ranging from 0 to 20 min/h, has been applied during the TNTs synthesis using a new dynamic hydrothermal reactor. It was proved that a long stirring cycle (more than 10 min/h) at 150 °C and an overall reaction time of 16 h promotes nanoribbons synthesis instead of nanotubes. In this context, a detailed mor…
Complex tribomechanical characterization of ZnO nanowires: nanomanipulations supported by FEM simulations
2016
In the present work, we demonstrate a novel approach to nanotribological measurements based on the bending manipulation of hexagonal ZnO nanowires (NWs) in an adjustable half-suspended configuration inside a scanning electron microscope. A pick-and-place manipulation technique was used to control the length of the adhered part of each suspended NW. Static and kinetic friction were found by a 'self-sensing' approach based on the strain profile of the elastically bent NW during manipulation and its Young's modulus, which was separately measured in a three-point bending test with an atomic force microscope. The calculation of static friction from the most bent state was completely reconsidered…
Structure and Dynamics of the Quasi-Liquid Layer at the Surface of Ice from Molecular Simulations
2018
We characterized the structural and dynamical properties of the quasi-liquid layer (QLL) at the surface of ice by molecular dynamics simulations with a thermodynamically consistent water model. Our simulations show that for three low-index ice surfaces only the outermost molecular layer presents short-range and mid-range disorder and is diffusive. The onset temperature for normal diffusion is much higher than the glass temperature of supercooled water, although the diffusivity of the QLL is higher than that of bulk water at the corresponding temperature. The underlying subsurface layers impose an ordered template, which produces a regular patterning of the ice/water interface at any tempera…