Search results for "PLASMA"

Ritz Solution for Transient Analysis of Variable-Stiffness Shell Structures

2020

The dynamic response of thin-walled structures is driven by mass and stiffness distribution. As such, variable-stiffness (VS) composites offer opportunities to tune structural dynamic responses. To this extent, efficient analysis tools become increasingly important for structural analysis and design purposes. In this work, an efficient and versatile Ritz method for free vibrations and linear transient analysis of VS doubly curved shell structures is presented. VS shell structures are modeled as an assembly of shell-like domains. The shell kinematics is based on the first-order shear deformation theory, and no further assumption is made on the shallowness or on the thinness of the structure.…

Il trattamento chirurgico con vite cannulata e PRP della pseudoartrosi dello scafoide carpale

2013

Nonunion is an important complication of carpal navicular fractures. The aim of this study is to report the medium term results of a reconstruction technique with cannulated screw combined with Platelet Rich Plasma (PRP) in Herbert fractures C (late consolidation), D1 (fibrous union without deformity) and D2 (pseudarthrosis with initial deformity).

I musei naturalistici come presidi ambientali e culturali. L'Orto botanico di Palermo

2013

La funzione degli Orti botanici, fondamentalmente, si esplica nella conservazione, nella ricerca scientifica, nelle attività espositive ed educative. I punti di forza dell’azione sociale di questi tipi di musei deriva sia dalla capacità di produrre e diffondere la conoscenza scientifica, sia dalla ricchezza patrimoniale posseduta. Una serie di emergenze planetarie e le prospettive incerte per l’ambiente, le società, le economie di tutte le nazioni del mondo configurano lo scenario d’oggi. Questa situazione richiede la costruzione collettiva di nuove forme di sentire, pensare e agire nella ricerca di soluzione ai problemi contemporanei. Si tratta quindi, per i musei scientifici, di intrapren…

Immune-mediated rippling muscle disease with myasthenia gravis: a report of seven patients with long-term follow-up in two.

2009

We report seven patients with immune-mediated rippling muscle disease (iRMD) and AChR-antibody positive myasthenia gravis (MG) without germline caveolin-3 gene mutations. We describe the follow-up of two patients and the clinical features of five new patients (1 female, 4 male, aged 32 to 69 years). These presented with significant generalized, exercise-induced and electrically-silent muscle rippling with myalgia, combined with generalized MG. In two of the seven patients, MG appeared before iRMD. Mediastinal imaging excluded thymic alterations in all, although two had other coincident tumours. Myalgia and rippling were aggravated by acetylcholinesterase-inhibitor treatment. Generalized MG …

Numerical resistive relativistic magnetohydrodynamics

2018

La presente tesis se desarrollada dentro del marco de la Magnetohidrodinámica Resistiva Relativistica (RRMHD; por sus siglas en inglés) y uno de sus principales objetivos es el caracterizar las condiciones físicas que optimizan la disipación de campos magnéticos en plasmas relativistas, especialmente en aquellos que son de interés astrofísico. Para alcanzar este objetivo, realizamos el estudio de los denominados modos de ruptura dobles, bajo condiciones ideales (IDTMs; por sus siglas en inglés) que maximizan sus tasas de crecimiento. Se demuestra que en el régimen relativista los IDTMs pueden crecer en escalas de tiempo de unos pocos tiempos característicos de Alfvén, desarrollando regímene…

Changes of several metabolic parameters of soya inoculated with phytopathogens at application nanochelates

2022

n greenhouse experiments changes in several metabolic parameters soybeans plants after inoculation by P. savastanoi pv. glycinea 9190, X. axonopodis pv. glycines 9192, BCMV, A. laidlawii on background pre-treatment by nanochelates (NHs) of V, Ge, Cu, Mo have been shown. The phenolic compounds content increased in leaves at inoculation by phytopathogens on background pre-treatment by NHs and without it. The content of H2O2 in leaves increased in variants: BCMV (+VNHs, GeNHs, CuNHs), 9192 (+VNHs, CuNHs), 9190 (+GeNHs, CuNHs), A. laidlawii+MoNHs. But it decreased in the variants: BCMV + MoNHs, A. laidlawii + VNHs, 9190 + VNHs, 9192 (+ GeNHs, CuNHs) compared to controls. The peroxidase activity…

Statistical study of the influence of CNTs purification and plasma functionalization on the properties of Polycarbonate-CNTs nanocomposites

2014

This work reports a statistical study on the relationship between the chemical-physical properties of CNTs, which vary by changing the conditions of purification and plasma treatment, and the macroscopic properties of PC-based nanocomposites. CNTs are synthesized and then purified in two different ways and used as fillers for the preparation of PC/CNTs nanocomposites. In some cases, oxygen plasma treatment is carried out to improve their affinity to the matrix. The CNTs are characterized by TGA, ICP/OES and FT-Raman spectroscopy, titration and morphological analysis. Mechanical, dynamic-mechanical, electrical and morphological tests are used for characterizing PC/CNTs nanocomposites.

Realizzazione di nanocompositi a base di PA6 e CNT funzionalizzato al plasma

2011

Plasma Functionalization of Multiwalled Carbon Nanotubes and Their Use in the Preparation of Nylon 6-Based Nanohybrids

2012

The possibility to obtain carbon nanotubes (CNT)/polyamide 6 composites with excellent mechanical properties in a simple, industrially scalable way is investigated. Commercial CNTs are treated by plasma while changing some key parameters (exposure time, plasma power, type of gas) in order to optimize the process and to achieve a sufficient degree of functionalization. The treated samples are characterized by Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The most interesting samples are selected to be used as reinforcing fillers, in different concentrations, in a polyamide 6 matrix. The mechanical tests show a dramatic increase of both tens…

Elemental and microbiota content in indoor and outdoor air using recuperation unit filters

2021

Detection and quantification of engineered nanomaterials in environmental systems require precise knowledge of the elemental composition, association, and ratios in homologous natural nanomaterials (NNMs). Here, we characterized soil NNMs at the single particle level using single particle-inductively coupled plasma-time of flight-mass spectrometer (SP-ICP-TOF-MS) in order to identify the elemental purity, composition, associations, and ratios within NNMs. Elements naturally present as a major constituent in NNMs such as Ti, and Fe occurred predominantly as pure/single metals, whereas elements naturally present at trace levels in NNMs occurred predominantly as impure/multi-metal NNMs such as…