Search results for "Fabric"

Water Absorption of Hemp Fibre Nonwovens Modified with Metal and Metal Oxide Nanoparticles

2015

In this paper changes of ability of hemp fibre nonwovens to absorb water after deposition of metal and metal oxide nanoparticles were investigated. Moisture content of samples after storage in different climatic conditions was determined using thermogravimetric method. The obtained results were compared with the results of previous research based on investigation of water absorption of metalized woven fabric of bast fibre. Analysis of measurements showed that nonwoven samples with surface treated in plasma attract water slightly better than sample with untreated surface; this was more pronounced in woven fabric samples. In turn, metal coatings reduced water sorption. Unlike woven fabric sam…

SAMs Based Device Fabrication and Characterization

2015

Despite the high potentiality of SAMs for spintronics, not many results exist at the moment in the literature. This lack of results is mainly due to the difficulty to fabricate the devices. The two main technological problems consist in the ferromagnetic electrodes compatibility issues with wet chemistry and the short-circuit formation during top electrode deposition. A part of this thesis has been committed to overcome these technological problems. This chapter will explain the steps that led us to the development of SAMs-based magnetic tunnel nanojunctions.

Introduction to Self-Assembled Monolayers

2015

One of the most exciting targets of molecular spintronics field is to go towards multifunctional devices where the properties can be accurately controlled and actively changed. Spin dependent hybridization at the metal/molecule interface could thus be used in the tailoring of the resistive and magnetoresistive response of spintronic devices exploiting chemistry versatility. In this new direction, Self-Assembled Monolayers (SAMs) appear as highly promising candidates since each part and function of this system can be modulated independently (like a molecular LEGO building unit). Despite highly promising, they are still scarcely investigated in the literature probably due to the difficulties …

Inverse Thermogelation of Aqueous Triblock Copolymer Solutions into Macroporous Shear-Thinning 3D Printable Inks

2020

Amphiphilic block copolymers that undergo (reversible) physical gelation in aqueous media are of great interest in ditIerent areas including drug delivery, tissue engineering, regenerative medicine, and biofabrication. We investigated a small library of ABA-type triblock copolymers comprising poly(2-methyl-2-oxazoline) as the hydrophilic shell A and different aromatic poly(2-oxazoline)s and poly(2-oxazine)s cores B in an aqueous solution at different concentrations and temperatures. Interestingly, aqueous solutions of poly(2-methyl-2-oxazoline)-block-poly(2-phenyl-2-oxazine)-block-poly(2-methyl-2-oxazoline) (PMeOx-b-PPheOzi-b-PMeOx) undergo inverse thermogelation below a critical temperatur…

Evaluation of bond strength of orthodontic brackets without enamel etching

2015

Background: to compare the shear bond strength of brackets with and without enamel etching. Material and Methods: In this study, 60 sound premolars were randomly divided into four different groups: 1- TXE group: Enamel etching + Transbond XT adhesive + Transbond XT composite. 2- TXS group: Transbond plus self-etch adhesive + Transbond XT composite. 3- PQ1E group: Enamel etching + PQ1 adhesive + Transbond XT composite. 4- PQ1 group: PQ1 adhesive + Transbond XT composite. The shear bond strengths of brackets were evaluated using universal testing machine at cross head speed of 0.5 mm/ min. The Adhesive Remnant Index (ARI) was also measured. One-way ANOVA, Tukey’s post hoc, Kruskal-wallis and …

Electrospun Poly(ethylene-co-vinyl alcohol)/Graphene Nanoplatelets Composites of Interest in Intelligent Food Packaging Applications

2018

Graphene nanoplatelets (GNPs) were synthetized from graphite powder and, thereafter, embedded in poly(ethylene-co-vinyl alcohol) (EVOH) fibers by electrospinning in the 0.1&ndash

A virtual reconfiguration of two destroyed neighborhoods in the Old Town of Palermo

2018

The proposed contribution deals with the topic of virtual three-dimensional reconstructions on an urban scale. The choice was oriented on significant samples of city portions that over the centuries have undergone substantial transformations or distortions: the aim is to reconstruct their history backwards, starting from the current survey and using the tools of virtual representation to reconfigure the forms of the past and tell their events. From here comes the idea to create, for pieces, a hypertextual study of the urban image of Palermo: the theme of the transformation of the city, of change and of complexity, opens up differentiated research paths. The hypertext choice was almost obvio…

Effects of fabrication on the mechanics, microstructure and micromechanical environment of small intestinal submucosa scaffolds for vascular tissue e…

2013

In small intestinal submucosa scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on success rate may be related to the mechanotransductory properties of the final microstructural organization of collagen fibers. We hypothesized that two fabrication parameters, 1) preservation (P) or removal (R) of a dense collagen layer present in SIS and 2) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on scaffold void area, microstructural anisotropy (fiber alignment) and mechanical anisotropy (global mechanical compliance). We further integrated our experimental measurements in a constitutive model to explore final effects on the micromechanic…

2017

The volume of ordinary materials decreases in response to a pressure increase exerted by a surrounding gas or liquid, i.e., the material volume compressibility is positive. Recently, poroelastic metamaterial architectures have been suggested theoretically that allow for an unusual negative effective static volume compressibility—which appears to be forbidden for reasons of energy conservation at first sight. The challenge in the three-dimensional (3D) fabrication of these blueprints lies in the necessary many hollow 3D crosses sealed by thin membranes, which we realize in this work by using 3D laser microlithography combined with a serendipitous mechanism. By using optical-microscopy cross-…

Investigation on Metal–Oxide Graphene Field-Effect Transistors With Clamped Geometries

2019

In this work, we report on the design, fabrication and characterization of Metal-Oxide Graphene Field-effect Transistors (MOGFETs) exploiting novel clamped gate geometries aimed at enhancing the device transconductance. The fabricated devices employ clamped metal contacts also for source and drain, as well as an optimized graphene meandered pattern for source contacting, in order to reduce parasitic resistance. Our experimental results demonstrate that MOGFETs with the proposed structure show improved high frequency performance, in terms of maximum available gain and transition frequency values, as a consequence of the higher equivalent transconductance obtained.