Search results for "Iode"

Caratterizzazione reologica di sistemi biodegradabili nanocompositi

2012

Asymmetric nanopore rectification for ion pumping, electrical power generation, and information processing applications

2011

Single-track, asymmetric nanopores can currently be functionalised with a spatially inhomogeneous distribution of fixed charges and a variety of pore tip shapes. Optimising the asymmetric nanopore characteristics is crucial for practical applications in nanofluidics. We have addressed here this question for three cases based on different input/output chemical and electrical signals: (i) ion pumping up a concentration gradient by means of a periodic, time-dependent bias potential, (ii) information processing with a single nanopore acting as the nanofluidic diode of a logic gate, and (iii) electrical energy harvesting using a nanopore that separates two solutions of different salt concentrati…

Energy conversion from external fluctuating signals based on asymmetric nanopores

2015

Electrical transduction from fluctuating external signals is central to energy conversion based on nanoscale electrochemical devices and bioelectronics interfaces. We demonstrate theoretically and experimentally a significant energy transduction from white noise signals using the electrical rectification of asymmetric nanopores in polymeric membranes immersed in aqueous electrolyte solutions. Load capacitor voltages of the order of 1 V are obtained within times of the order of 1 min by means of nanofluidic diodes which convert zero time-average potentials of amplitudes of the order of 1 V into average net currents. We consider single-nanopore and multipore membranes to show that the convers…

Electrical network of nanofluidic diodes in electrolyte solutions: Connectivity and coupling to electronic elements

2016

[EN] We consider a nanopore network with simple connectivity, demonstrating a two-dimensional circuit (full-wave rectifier) with ensembles of conical pores acting as nanofluidic diodes. When the bridge nanopore network is fed with an input potential signal of fluctuating polarity, a fixed output polarity is obtained. The full-wave rectification characteristics are demonstrated with square, sinusoidal, and white noise input waveforms. The charging of a load capacitor located between the two legs of the bridge demonstrates that the nanofluidic network is effectively coupled to this electronic element. These results can be relevant for energy transduction and storage procedures with nanopores …

Modulation of current-time traces by two-pore arrangements of polyimide nanofluidic diodes

2019

Liquid state arrangements of two polymeric membranes with single conical nanopores constitute nanofluidic diodes that allow a rich electrical functionality based on the modulation of individual conductances in aqueous electrolyte solutions. In particular, the prescribed sequences of current-time traces can be obtained by preprogramed switching between series and parallel pore connection arrangements. Hybrid nanopore-solid-state circuits are also possible. The basic applied physics of the nanofluidic diode arrangements can be understood from simple circuit theory concepts and should be of widespread interest to sensing and actuating procedures, controlled release dispensers, and energy conve…

Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.

2012

We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…

Desarrollo y caracterización de nuevos nanobiocomposites con propiedades mejoradas mediante varios métodos de procesado de interés en envasado de ali…

2015

El presente trabajo tiene como objetivo mejorar las propiedades de matrices biopoliméricas para su uso en aplicaciones de envasado de alimentos mediante el desarrollo de nanobiocompuestos utilizando diferentes metodologías de procesado o estrategias de incorporación de materiales nanoestructurados en el interior de las matrices biopoliméricas. Dos estrategias de incorporación fueron empleadas. La primera de ellas estaba basada en una pre-incorporación de los aditivos nanoestructurados, también llamados nanoaditivos, en oligómeros de ácido láctico mediante tecnologías de polimerización in situ (específicamente policondensación), dando lugar a masterbatches que, posteriormente, se mezclaban c…

Ultra-Low Noise Multiwalled Carbon Nanotube Transistors

2013

We report an experimental noise study of intermediate sized quasi ballistic semiconducting multiwalled carbon nanotube (IS-MWCNT) devices. The noise is two orders of magnitude lower than in singlewalled nanotubes (SWCNTs) and has no length dependence within the studied range. In these channel limited devices with small or negligible Schottky barriers the noise is shown to originate from the intrinsic potential fluctuations of charge traps in the gate dielectric. The gate dependence of normalized noise can be explained better using ballistic the charge noise model rather than diffusive McWhorter’s model. The results indicate that the noise properties of IS-MWCNTs are closer to SWCNTs than th…

Microbial Degradation of 2,4,6-Trinitrotoluene In Vitro and in Natural Environments

2013

2,4,6-Trinitrotoluene (TNT) is a nitroaromatic explosive that was released into soil and water ecosystems mainly due to its massive use during the two world wars.

Contributi alla interpretazione, conservazione e restauro dei manufatti storico-artistici dell’Orto Botanico di Palermo: il Paride di Nunzio Morello

2017

Contributions to the interpretation, conservation and restoration of the historical and artistic artifacts of the Botanical Garden of Palermo: the Paride by Nunzio Morello – Purely cognitive and conservative requirements of the historical-artistic heritage of the Botanical Garden of the University of Palermo, have led the authors to present one of the most representative monuments of such Garden that is of great artistic and cultural value in the City of Palermo: the Paride Pensante, a marble sculpture made in 1839 by the Palermo sculptor Nunzio Morello - a pupil of the most famous artist Valerio Villareale - donated to his homeland and placed in the men- tioned Botanical Garden, in the squ…