Search results for "Additive"
showing 10 items of 297 documents
Skewness and kurtosis of 1/f noise in semiconductor devices
2000
An experimental investigation of the third and fourth moments of the 1/f noise of two different electronic devices is reported. The skewness and the kurtosis of the noise voltage data are estimated. Although the devices under investigation have similar noise power spectral density, the time waveforms are shown to have slightly different statistical properties. In both cases, a small deviation from Gaussian distribution is observed.
How do normalization schemes affect net spillovers? A replication of the Diebold and Yilmaz (2012) study
2019
Abstract This paper replicates the Diebold and Yilmaz (2012) study on the connectedness of the commodity market and three other financial markets: the stock market, the bond market, and the FX market, based on the Generalized Forecast Error Variance Decomposition, GEFVD. We show that the net spillover indices (of directional connectedness), used to assess the net contribution of one market to overall risk in the system, are sensitive to the normalization scheme applied to the GEFVD. We show that, considering data generating processes characterized by different degrees of persistence and covariance, a scalar-based normalization of the Generalized Forecast Error Variance Decomposition is pref…
Light absorption and conversion in solar cell based on Si:O alloy
2013
Thin film Si:O alloys have been grown by plasma enhanced chemical vapor deposition, as intrinsic or highly doped (1 to 5 at. % of B or P dopant) layers. UV-visible/near-infrared spectroscopy revealed a great dependence of the absorption coefficient and of the optical gap (Eg) on the dopant type and concentration, as Eg decreases from 2.1 to 1.9 eV, for the intrinsic or highly p-doped sample, respectively. Thermal annealing up to 400 °C induces a huge H out-diffusion which causes a dramatic absorption increase and a reduction of Eg, down to less than 1.8 eV. A prototypal solar cell has been fabricated using a 400 nm thick, p-i-n structure made of Si:O alloy embedded within flat transparent c…
Inactivation kinetics of pectin methyl esterase under combined thermal–high pressure treatment in an orange juice–milk beverage
2008
Abstract The inactivation kinetics of PME in an orange juice–milk beverage system treated by thermal (65–80 °C) and combined thermal (25–65 °C)–high pressure (0.1–700 MPa) processes were fitted using a biphasic model. About 6–8% of the initial activity corresponding to the heat and pressure stable fraction was observed. For complete inactivation a treatment at 90 °C, 1 min or 700 MPa at 55 °C for 2 min was necessary showing the protective effect of the orange–milk media. The extent of inactivation was different in the orange matrices showing that PME was more thermostable in the orange juice–milk based beverage system as compared to the purified enzyme in a buffer system. On the other hand,…
Sputtered cuprous oxide thin films and nitrogen doping by ion implantation
2016
Abstract The structural, optical and electrical properties of sputtered cuprous oxide thin films have been optimized through post-deposition thermal treatments. Moreover we have studied the effects of nitrogen doping introduced by ion implantation followed by the optimized oxidant thermal annealing. Three concentrations have been used, 0.6 N%, 1.2 N%, and 2.5 N%. Along with the preservation of the Cu 2 O phase, a slight optical band gap narrowing and a significant conductivity enhancement has been observed with respect to the undoped samples. These results can be justified by the absence of further oxygen vacancies promoted by dopant introduction and by the substitution of O atoms by N ones…
Recovery of colorants from red prickly pear peels and pulps enhanced by pulsed electric field and ultrasound
2016
Abstract The aim of this work was to evaluate the potential of the non-conventional pre-treatments; pulsed electric fields (PEFs) and ultrasounds (USNs), to enhance the extraction of red colorants from red prickly pear ( Opuntia stricta Haw.) peels and pulps. The overall goal was to valorize the thick part of the fruit, being discarded for fruit's consumption. PEF and USN treatments were first optimized using fruit slices, followed by a supplementary aqueous extraction (+ SAE) up to 1 h. The optimal conditions were then applied for peels and pulps, separately. Results showed that PEF + SAE and USN + SAE enhanced significantly the extraction of red colorants (betanin/isobetanin), compared to…
Resource or waste? A perspective of plastics degradation in soil with a focus on end-of-life options.
2018
‘Capable-of-being-shaped’ synthetic compounds are prevailing today over horn, bone, leather, wood, stone, metal, glass, or ceramic in products that were previously left to natural materials. Plastic is, in fact, economical, simple, adaptable, and waterproof. Also, it is durable and resilient to natural degradation (although microbial species capable of degrading plastics do exist). In becoming a waste, plastic accumulation adversely affects ecosystems. The majority of plastic debris pollutes waters, accumulating in oceans. And, the behaviour and the quantity of plastic, which has become waste, are rather well documented in the water, in fact. This review collects existing information on pla…
Parallel Schwarz methods for convection-dominated semilinear diffusion problems
2002
AbstractParallel two-level Schwarz methods are proposed for the numerical solution of convection-diffusion problems, with the emphasis on convection-dominated problems. Two variants of the methodology are investigated. They differ from each other by the type of boundary conditions (Dirichlet- or Neumann-type) posed on a part of the second-level subdomain interfaces. Convergence properties of the two-level Schwarz methods are experimentally compared with those of a variant of the standard multi-domain Schwarz alternating method. Numerical experiments performed on a distributed memory multiprocessor computer illustrate parallel efficiency of the methods.
Generative design and parametric / topological optimization of cellular structures bio-inspired by additive manufacturing
2022
Biomimicry is the practice of learning from nature and imitating its different functionalities. Nature proposes complex forms and objects which inspired designers and engineers to conceive and find solutions for their engineering problems. The fabrication of these complex objects is particularly assured by the different Additive Manufacturing (AM) techniques. Generally, biomimicry can be addressed at different levels, forms, textures, and behaviors, but in AM, it is presented under two main types. The first is the customization of parts (medical prosthesis, implants or custom sport equipments). And the second consists in the optimization for specific properties such as stiffness and lightne…
Half-width plots, a simple tool to predict peak shape, reveal column kinetics and characterise chromatographic columns in liquid chromatography: Stat…
2013
Peak profiles in chromatography are characterised by their height, position, width and asymmetry; the two latter depend on the values of the left and right peak half-widths. Simple correlations have been found between the peak half-widths and the retention times. The representation of such correlations has been called half-width plots. For isocratic elution, the plots are parabolic, although often, the parabolas can be approximated to straight-lines. The plots can be obtained with the half-widths/retention time data for a set of solutes experiencing the same kinetics, eluted with a mobile phase at fixed or varying composition. When the analysed solutes experience different resistance to mas…