Search results for "NICS"
showing 10 items of 15025 documents
Effect of the Si doping on the properties of AZO/SiC/Si heterojunctions grown by low temperature pulsed laser deposition
2020
Abstract The structural and photoelectrical properties of Al-doped ZnO (AZO)/SiC/p-Si and AZO/SiC/n-Si heterojunctions, fabricated at low temperature by pulsed laser deposition, were investigated by means of a number of techniques. Raman analysis indicates that SiC layers have the cubic 3C-SiC phase, whilst X-ray diffraction measurements show that AZO films exhibit a hexagonal wurtzite structure, highly textured along the c-axis, with average crystallites size of 35.1 nm and lattice parameter c of 0.518 nm. The homogeneous and dense surface morphology observed by scanning electron microscopy was confirmed by atomic force microscopy images. Moreover, UV–Vis-NIR spectra indicated a high trans…
Particle radiation in microelectronics
2012
The unavoidable presence of particle radiation in space and on the ground combined with constantly evolving technology necessitates a deep understanding of the basic mechanisms underlying radiation effects in materials and electronic devices. This thesis provides an overview of the different radiation environments, with a review of the interaction mechanisms between energetic particles and matter. In this work a new semi-empirical model for estimating the electronic stopping force of solids for heavy ions is introduced. Radiation effects occurring in microelectronics due to particle radiation are also discussed with a brief introduction to radiation hardness assurance (RHA) testing of elect…
Localized surface plasmon resonance in silver nanoparticles: Atomistic first-principles time-dependent density-functional theory calculations
2015
We observe using ab initio methods that localized surface plasmon resonances in icosahedral silver nanoparticles enter the asymptotic region already between diameters of 1 and 2 nm, converging close to the classical quasistatic limit around 3.4 eV. We base the observation on time-dependent density-functional theory simulations of the icosahedral silver clusters Ag$_{55}$ (1.06 nm), Ag$_{147}$ (1.60 nm), Ag$_{309}$ (2.14 nm), and Ag$_{561}$ (2.68 nm). The simulation method combines the adiabatic GLLB-SC exchange-correlation functional with real time propagation in an atomic orbital basis set using the projector-augmented wave method. The method has been implemented for the electron structure…
Fibre fragment distribution in a single-fibre composite tension test
2001
Abstract Single fibre fragmentation tests are performed for brittle fibres with Weibull strength distribution and different surface treatments. The fragmentation process is modelled and closed-form expressions for break spacing distribution are obtained. The model accounts for the effect of finite fibre length on the initial fragmentation as well as for break interaction on the advanced fragmentation stage. It is assumed that the exclusion zone due to fibre–matrix interface failure and stress recovery in the fibre is linearly dependent on the applied load. This assumption is validated experimentally. The derived theoretical average fragment length dependence on applied load is used to deter…
Time resolved emission at 1.3 μm of a single InAs quantum dot by using a tunable fibre Bragg grating
2013
Photoluminescence and time resolved photoluminescence from single metamorphic InAs/GaAs quantum dots (QDs) emitting at 1.3 mu m have been measured by means of a novel fibre-based characterization set-up. We demonstrate that the use of a wavelength tunable fibre Bragg grating filter increases the light collection efficiency by more than one order of magnitude as compared to a conventional grating monochromator. We identified single charged exciton and neutral biexciton transitions in the framework of a random population model. The QD recombination dynamics under pulsed excitation can be understood under the weak quantum confinement potential limit and the interaction between carriers at the …
Changes in biomechanics of skiing at maximal velocity caused by simulated 20 km skiing race using V2 skating technique
2018
This study investigated how the fatigue caused by a 20-km simulated skating cross-country skiing race on snow affects the final spurt performance from a biomechanical perspective. Subjects performed a 100-m maximal skiing trial before and at the end of the simulated race. Cycle characteristics, ground reaction forces from skis and poles, and muscle activity from eight muscles were recorded during each trial. Results showed that subjects were in a fatigued state after the simulated race manifested by 11.6% lower skiing speed (P<.01). The lower skiing speed was related to an 8.0% decrease in cycle rate (P<.01), whereas cycle length was slightly decreased (tendency). In temporal patterns, rela…
Dissimilar titanium-aluminum skin-stringer joints by FSW: process mechanics and performance
2022
Ever since its inception, friction stir welding (FSW) is being validated by scientific investigations as an effective substitution for fusion-based conventional joining technologies. One of the main strengths of FSW is the possibility to produce dissimilar joints, even using materials extremely different in terms of thermal and mechanical properties. The goal of the present research is to investigate the feasibility of both Al-Ti skin-stringer and reversed Ti-Al skin-stringer joints, highlighting the effect of joint configuration and main process parameters on material flow and joint mechanical properties. During the investigation, the essentiality of the proper heat input through balancing
A fluorescence study of the loading and time stability of doxorubicin in sodium cholate/PEO-PPO-PEO triblock copolymer mixed micelles
2019
Abstract Hypothesis Doxorubicin hydrochloride (DX) is one of the most powerful anticancer agents though its clinical use is impaired by severe undesired side effects. DX encapsulation in nanocarrier systems has been introduced as a mean to reduce its toxicity. Micelles of the nonionic triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) (PEO-PPO-PEO), are very promising carrier systems. The positive charge of DX confines the drug to the hydrophilic corona region of the micelles. The use of mixed micelles of PEO-PPO-PEO copolymers and a negatively charged bile salt should favour the solubilization of DX in the apolar core region of the micelles. Experiments We st…
A Telemetry, Tracking, and Command Antennas System for Small-Satellite Applications
2019
Circularly polarized (CP) antennas are used in space applications for telemetry tracking and command (TT&
Enhancing the Iterative Smoothed Particle Hydrodynamics Method
2021
Motivated by recent research on the iterative approach proposed for the smoothed particle hydrodynamics (ISPH) method, some ideas to improve the process are introduced. The standard procedure is enhanced iterating on the residuals preserving the matrix-free nature of the process. The method is appealing providing reasonable results with disordered data distribution too and no kernel variations are needed in the approximation. This work moves forward with a novel formulation requiring a lower number of iterations to reach a desired accuracy. The computational procedure is described and some results are introduced to appreciate the proposed formulation.