Search results for "Composite"
showing 10 items of 4584 documents
Enhanced Drug Delivery to the Skin Using Liposomes
2018
Background:. Enhancing drug delivery to the skin has importance in many therapeutic strategies. In particular, the outcome in vascularized composite allotransplantation mainly depends on systemic immunosuppression to prevent and treat episodes of transplant rejection. However, the side effects of systemic immunosuppression may introduce substantial risk to the patient and are weighed against the expected benefits. Successful enhancement of delivery of immunosuppressive agents to the most immunogenic tissues would allow for a reduction in systemic doses, thereby minimizing side effects. Nanoparticle-assisted transport by low temperature–sensitive liposomes (LTSLs) has shown some benefit in a…
An academic performance indicator using flexible multi-criteria methods
2021
Composite indicators are a very useful tool for conveying summary information on the overall performance of institutions and facilitating decision-making. Increasingly, there is a demand for indicators that allow performance to be assessed after the implementation of a strategy. This has several difficulties, and in this paper, we address three of them: how to evaluate at different points in time, how to estimate the weighting of the criteria and how to normalize the data. Our proposal is based on multicriteria techniques, using a recent method, uwTOPSIS, and is applied to data collected from 2975 students enrolled in the first year of science and engineering at the Industrial University of…
Paramagnetic germanium-related centers induced by energetic radiation in optical fibers and preforms
2009
International audience; We investigated the creation processes of Ge-related paramagnetic point defects in silica fibers and preforms, doped with different amounts of germanium, and X-ray irradiated at several radiation doses. Different paramagnetic defect species, like GeE0, Ge(1) and Ge(2), were revealed by electron paramagnetic resonance measurements and their concentration was studied as a function of the irradiation dose. The comparison with the optical absorption spectra points out the main role of Ge(1) on the optical transmission loss of fibers in the UV region.
Effects of clearance on thick, single-lap bolted joints using through-the-thickness measuring techniques
2011
Composite materials have increasingly become more common in ground transportation. As this occured thicker panels, as compared to composite panels used in aviation, become necessary in order to withstand high impact loads and day to day degradation. The effectiveness of these panels was often limited by the strength of the joint in which the panel was attached to the frame of the vehicle. Investigating methods of reducing strain concentrations within these joints would increase the effectiveness in using composite materials in ground transportation applications by increasing the load necessary for joint failure to occur. In this study, fiber optic strain gages were embedded in a composite p…
Design of Er3+-doped chalcogenide glass laser for MID-IR application
2009
Abstract The feasibility of a photonic crystal fiber laser (PCF laser), made of a novel Er 3+ -doped chalcogenide glass and operating at the wavelength λ s = 4.5 μm is investigated. The design is performed on the basis of spectroscopic and optical parameters measured on a fabricated Er 3+ -doped Ga 5 Ge 20 Sb 10 S 65 chalcogenide bulk sample. The simulations have been performed by employing a home made numerical code that solves the multilevel rate equations and the power propagation equations via a Runge-Kutta iterative method. The numerical results indicate that a laser exhibiting slope efficiency close to the maximum theoretical one and a wide tunability in the wavelengths range where t…
TeO2-ZnO-La2O3 tellurite glass system investigation for mid-infrared robust optical fibers manufacturing
2021
Abstract TeO2-ZnO-La2O3 (TZL) ternary glasses were investigated in order to manufacture step-index optical fibers with low optical losses in the near- and mid-infrared ranges and superior mechanical properties. To identify appropriate TZL glass compositions for optical fibers manufacturing, the whole vitreous domain of the ternary diagram was explored by characterizing bulk samples from thermal and optical point of view. Investigations were focused on understanding how the refractive index evolves as a function of the composition. For this, several parameters were analyzed such as density, molar volume, oxygen packing density, molar refractivity, polarizability and optical basicity. Finally…
Acousto-optic interaction in polyimide coated optical fibers with flexural waves
2017
Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupling in optical fibers with robust protective coating.
Optic fibre as a transducer of tendomuscular forces
1996
Direct in vivo tendon force measurements open up new possibilities for understanding of muscle-tendon loads during natural locomotion. The present report presents a new optic fibre method for such applications. The method is based on light intensity modulation by mechanical modification of the geometric properties of the optic fibre. A special optic fibre with a plastic covering buffer and with a total diameter of either 265 microns or 500 microns was carefully prepared at both ends for receiving and transmitting light. The fibre was inserted through the rabbit common calcaneal tendon with a 20 gauge needle. By removing the needle the optic fibre remained in situ. Static loading demonstrate…
X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions
2011
International audience; We report an experimental study based on confocal microscopy luminescence (CML) and electron paramagnetic resonance (EPR) measurements to investigate the effects of the X-ray (from 50 krad to 200 Mrad) on three specific multistep Ge doped fibers obtained from the same preform by changing some of the drawing conditions (tension and speed). CML data show that, both before and after the irradiation, Germanium Lone Pair Center (GLPC) concentrations are similarly distributed along the diameters of the three fibers and they are partially reduced by irradiation. The irradiation induces also the Non Bridging Oxygen Hole Center (NBOHC) investigated by CML and other paramagnet…
Influence of Drawing Conditions on the Properties and Radiation Sensitivities of Pure-Silica-Core Optical Fibers
2012
International audience; The structure and radiation sensitivities of three different pure-silica-core fluorine-doped-cladding optical fibers, made from the same original preform, were investigated by several experimental techniques. The fibers were obtained by changing the drawing speed and tension in the typical ranges of values used for the radiation-tolerant waveguides. The Raman spectroscopy revealed no significant difference among the fibers before irradiation. At variance, the comparison between the fibers and their associated preform highlighted an increase in the amplitude of the D2 band that is related to the concentration of 3 member rings. Moreover, in the zones where the D2 incr…