Search results for "FLE"
showing 10 items of 3517 documents
MCM-41-CdS nanoparticle composite material: Preparation and characterization
2010
The preparation and characterization of a hierarchical material constituted by a mesoporous silica MCM-41 whose mesochannels contain CdS nanoparticles capped with both bis(2-ethylhexyl) amine and bis(2-ethylhexyl) sodium sulfosuccinate is reported. MCM-41 powder was synthesized by using the LCT methodology. CdS nanoparticles were obtained within the inversed micelle core of a water/ AOT/n-heptane microemulsion. Nanoparticles growth was followed by means of UV–Vis spectroscopy and was inhibited by BEA addition. The CdS-capped nanoparticles were separated by centrifugation, washed with water and ethanol and finally dispersed in n-heptane. The insertion of CdS nanoparticles into MCM-41 mesocha…
Induced Modification of Flexural Toughness of Natural Hydraulic Lime Based Mortars by Addition of Giant Reed Fibers
2020
Abstract Nowadays, there is a growing need to reduce the environmental impact generated by the use of inorganic materials for building applications. The aim of this work is to investigate the bio-lime based mortar flexural toughness improvement due to the addition of common reed fibers (Arundo donax L.) in order to evaluate their possible application as ductile eco-compatible prefabricated bricks or laying and joint mortars for masonry. Different sets of specimens were tested by varying the fiber weight content and the fiber length. Moreover, chemical treatments with Linseed Oil and Polyethylene glycol (PEG) were performed to improve the physical and mechanical properties of the fibers as w…
Flexural strength and microhardness of anterior composites after accelerated aging
2016
Background This study aimed to evaluate the flexural strength and microhardness of three different anterior composites after 10 000 thermocycles. Material and Methods The mechanical properties of a nano-fill composite (Filtek Ultimate Universal Restorative (FUR) (Enamel)), a nano-hybrid composite (Clearfil Majesty ES2 (ES2) (Enamel)), and a micro-hybrid composite (G Aenial Anterior (GAA)) were investigated in this study. For the microhardness test, 8-mm diameter and 2-mm thickness composite discs were used (n = 10), and for the flexural strength test, 25x2x2 mm bar-shaped specimens were prepared (n = 13). The specimens were tested at 24 h and after 10 000 thermocycles. Data were analyzed us…
Stainless steel grids for confinement of clay brick masonry columns
2016
This work presents the results of an experimental investigation on the behavior of 21 solid clay brick columns internally strengthened by stainless steel grids placed in the horizontal joints of mortar. This reinforcing technique can be applied as a constructive technique for new construction or as a retrofitting technique for existing structures (old structures to be reconstructed by original constructive method and internal reinforcement). Monotonic compressive loading tests were carried out under concentric and eccentric load. The effects of different numbers of steel grids and eccentricity of the external load were examined. Also, a detailed characterization of the constituent materials…
Flexural and Shear Resistance of Steel Fiber–Reinforced Lightweight Concrete Beams
2014
In the present paper an analytical model is proposed that is able to determine the shear resistance of lightweight reinforced concrete beams with longitudinal bars, in the presence of reinforcing steel fibers. The model is based on the evaluation of the resistance contribution resulting from beam and arch actions. For the resistance contribution of main bars in tension, the residual bond adherence of steel bars and the crack spacing of reinforced concrete (RC) beams in the presence of fibers are considered. The contribution in terms of postcracking resistance in the tension zone of the beams is also included. The model was verified on the basis of experimental data available in the literatu…
Neutron scattering study of melting ofHe3surface layers
1982
The melting of the incommensurate phase of $^{3}\mathrm{He}$ submonolayers adsorbed on Grafoil was investigated by elastic neutron scattering. The temperature dependence of the nearest-neighbor distance, the coherence length, and the peak intensity of the structure factor can be explained by a simple model assuming a melting transition which is driven by thermally created lattice defects.
Polar phonons in relaxor ferroelectric 0.2PSN-0.4PMN-0.4PZN
2008
Relaxor ferroelectrics 0-2PbSc(1/2)Nb(1/2)O(3) - 0.4PbMg(1/3)Nb(2/3)O(3)-0.4PbZn(1/3)Nb(2/3)O(3) ceramics were studied by means of the Fourier transform infrared reflection and THz transmission spectroscopy in the temperature range of 20-500 K. On heating from low temperatures, the A(1) component of the strongly split TO1 mode softens towards the Burns temperature, but the softening ceases near 400 K, which could be a signature of polar cluster percolation temperature.
CO2 to Liquid Fuels: Photocatalytic Conversion in a Continuous Membrane Reactor
2018
The photocatalytic reduction of CO, into value-added chemicals using sunlight is a promising approach to promote energy-bearing products, mitigating the adverse effects of anthropogenic CO2 emissions. In this work, exfoliated C3N4 was incorporated into Nafion matrix and used in a continuous photocatalytic reactor for converting CO2 into liquid fuels. Comprehensive structural and morphological diffuse reflectance spectroscopy (DRS), FT-IR, ATR-IR, and SEM measurements were performed for C3N4-loaded Nafion membrane and then compared with those of a Nafion membrane without any catalyst. The synergic effect of C3N4 organic catalyst embedded in a Nafion dense matrix and a continuous operating mo…
MATERIALS AND PROCESSING ISSUES FOR THE MANUFACTURING OF INTEGRATED PASSIVE AND ACTIVE DEVICES ON FLEXIBLE SUBSTRATES
2008
Plast_ICs is a Public/Private Laboratory funded by Italian Government aimed to build a novel technological platform for the development of flexible electronics, mainly, but not solely, based on thin inorganic films. Integration of different functions, on single and/or multiple plastic foils, to generate a smart system is the final goal of the project. The building blocks of the platform will be presented, starting from the different plastic substrates characterization, going through the development of active devices, such as thin-film- transistors, and passive devices, like thin-film- resistors, capacitors, inductors. Fully inorganic elementary devices, based on optical patterning and in va…
Mechanical behavior of single-layer ceramized zirconia abutments for dental implant prosthetic rehabilitation
2013
Objectives: This study was undertaken to characterize the mechanical response of bare (as-received) and single-layer ceramized zirconia abutments with both internal and external connections that have been developed to enhanced aesthetic restorations. Material and Methods: Sixteen zirconia implant abutments (ZiReal Post®, Biomet 3i, USA) with internal and external connections have been analyzed. Half of the specimens were coated with a 0.5mm-thick layer of a low-fusing fluroapatite ceramic. Mechanical tests were carried out under static (constant cross-head speed of 1mm/min until fracture) and dynamic (between 100 and 400N at a frequency of 1Hz) loading conditions. The failure location was i…