Search results for "COPI"

Pressure-responsive mesoscopic structures in room temperature ionic liquids

2015

Among the most spectacular peculiarities of room temperature ionic liquids, their mesoscopically segregated structural organization keeps on attracting attention, due to its major consequences for the bulk macroscopic properties. Herein we use molecular dynamics simulations to explore the nm-scale architecture in 1-octyl-3-methylimidazolium tetrafluoroborate, as a function of pressure. This study reveals an intriguing new feature: the mesoscopic segregation in ionic liquids is characterized by a high level of pressure-responsiveness, which progressively vanishes upon application of high enough pressure. These results are in agreement with recent X-ray scattering data and are interpreted in …

Polymer solutions: Equilibrium clusters versus shear clusters

2021

Abstract Polymer solutions are inhomogeneous on mesoscopic scales as a result of chemical bonds linking their monomeric units. This situation leads to polymer clusters within which the polymer concentration c cluster is only a small fraction of the overall concentration c. The ratio c/ c cluster (overlap parameters Ω ) quantifies the number of clusters that need to overlap to yield c. Equilibrium clusters (minimization of Gibbs energy) and shear clusters (minimization of entropy production) differ fundamentally where Ω equil ≥ Ω shear . Only in the vicinity of the glass transition temperature and at high concentration the opposite is the case. Experimental information on Ω equil as a functi…

Discrete-lattice theory for Frenkel-defect aggregation in irradiated ionic solids

1998

Institut fu ¨r Physikalische und Theoretische Chemie, Technische Universitat Braunschweig, D-38106 Braunschweig, Germany~Received 11 September 1997; revised manuscript received 6 April 1998!A microscopic theory of diffusion-controlled aggregation of radiation Frenkel defects—called in ionic solidsH and F centers—is presented. This is based on a discrete-lattice formalism for the single defect densities~concentrations! and the coupled joint densities of similar and dissimilar defects treated in terms of a modifiedKirkwood superposition approximation. The kinetics of defect aggregation is studied in detail; the cooperativecharacter of this process for both types of complementary defects is sho…

Il cammino del sole, gli spazi del giorno. Piano urbanistico del comune di Grammichele (CT) su lastra di ardesia dipinta

2008

Automatic Biological Cell Counting Using a Modified Gradient Hough Transform

2017

AbstractWe present a computational method for pseudo-circular object detection and quantitative characterization in digital images, using the gradient accumulation matrix as a basic tool. This Gradient Accumulation Transform (GAT) was first introduced in 1992 by Kierkegaard and recently used by Kaytanli & Valentine. In the present article, we modify the approach by using the phase coding studied by Cicconet, and by adding a “local contributor list” (LCL) as well as a “used contributor matrix” (UCM), which allow for accurate peak detection and exploitation. These changes help make the GAT algorithm a robust and precise method to automatically detect pseudo-circular objects in a microscop…

Nanotexturing To Enhance Photoluminescent Response of Atomically Thin Indium Selenide with Highly Tunable Band Gap.

2016

Brotons-Gisbert, Mauro et al.

Nonequilibrium depletion interactions in active microrheology.

2017

Entropic depletion forces arise between mesoscopic bodies that are immersed in a suspension of macromolecules, such as colloid-polymer mixtures. Here we consider the case of a driven colloidal probe in the presence of another, passive colloidal particle, both solvated in an ideal bath of small spherical particles. We calculate the nonequilibrium forces mediated by the depletants on the two colloidal particles within a dynamical superposition approximation (DSA) scheme. In order to assess the quality of this approximation, and to obtain the colloidal microstructure around the driven probe, we corroborate our theoretical results with Brownian dynamics simulations.

Resolving Bio–Nano Interactions of E. coli Bacteria–Dragonfly Wing Interface with Helium Ion and 3D-Structured Illumination Microscopy to Understand …

2020

Obtaining a comprehensive understanding of the bactericidal mechanisms of natural nanotextured surfaces is crucial for the development of fabricated nanotextured surfaces with efficient bactericidal activity. However, the scale, nature, and speed of bacteria-nanotextured surface interactions make the characterization of the interaction a challenging task. There are currently several different opinions regarding the possible mechanisms by which bacterial membrane damage occurs upon interacting with nanotextured surfaces. Advanced imaging methods could clarify this by enabling visualization of the interaction. Charged particle microscopes can achieve the required nanoscale resolution but are …

Toward fast malaria detection by secondary speckle sensing microscopy

2012

Diagnosis of malaria must be rapid, accurate, simple to use, portable and low cost, as suggested by the World Health Organization (WHO). Despite recent efforts, the gold standard remains the light microscopy of a stained blood film. This method can detect low parasitemia and identify different species of Plasmodium. However, it is time consuming, it requires well trained microscopist and good instrumentation to minimize misinterpretation, thus the costs are considerable. Moreover, the equipment cannot be easily transported and installed. In this paper we propose a new technique named "secondary speckle sensing microscopy" ((SM)-M-3) based upon extraction of correlation based statistics of s…

UTILIZZO DELLA MICROSCOPIA ELETTRONICA A SCANSIONE PER L’ANALISI MORFOLOGICA E ULTRASTRUTTURALE DI CARIOSSIDI DI FRUMENTO DURO

2013

Abstract: Questo studio è stato svolto nell’ambito del Progetto”ALISAL”: Miglioramento delle proprietà igienico-sanitarie, salutistiche e funzionali di materie prime per l’alimentazione dell’uomo e/o degli animali, promosso dal Ministero delle Politiche Agricole, Alimentari e Forestali italiano (MIPAAF). Lo studio in oggetto è parte del progetto sopra indicato il cui scopo era quello di selezionare nuovi genotipi di cereali, in particolare di frumento duro, al fine di migliorare le caratteristiche nutrizionali e tecnologiche dell’ intera filiera produttiva. La fase preliminare dello sviluppo progettuale è stata quella di sviluppare un metodo per la caratterizzazione morfologica e ultrastrut…