Search results for "Parametric"
showing 10 items of 980 documents
Effect of parametric variation of center frequency and bandwidth of morlet wavelet transform on time-frequency analysis of event-related potentials
2017
Time-frequency (TF) analysis of event-related potentials (ERPs) using Complex Morlet Wavelet Transform has been widely applied in cognitive neuroscience research. It has been widely suggested that the center frequency (fc) and bandwidth (σ) should be considered in defining the mother wavelet. However, the issue how parametric variation of fc and σ of Morlet wavelet transform exerts influence on ERPs time-frequency results has not been extensively discussed in previous research. The current study, through adopting the method of Complex Morlet Continuous Wavelet Transform (CMCWT), aims to investigate whether time-frequency results vary with different parametric settings of fc and σ. Besides, …
Enhanced supercontinuum generation in tapered tellurite suspended core fiber
2015
Abstract We demonstrate 400-THz (0.6–3.3 µm) bandwidth infrared supercontinuum generation in a 10 cm-long tapered tellurite suspended core fiber pumped by nJ-level 200-fs pulses from an optical parametric oscillator. The increased nonlinearity and dispersion engineering extended by the moderate reduction of the fiber core size are exploited for supercontinuum optimization on both frequency edges (i.e., 155-THz overall gain), while keeping efficient power coupling into the untapered fiber input. The remaining limitation of supercontinuum bandwidth is related to the presence of the high absorption beyond 3 µm whereas spectral broadening is expected to fully cover the glass transmission window…
Periodic and quasi-periodic orbits of the dissipative standard map
2011
We present analytical and numerical investigations of the dynamics of the dissipative standard map. We first study the existence of periodic orbits by using a constructive version of the implicit function theorem; then, we introduce a parametric representation, which provides the interval of the drift parameter ensuring the existence of a periodic orbit with a given period. The determination of quasi--periodic attractors is efficiently obtained using the parametric representation combined with a Newton's procedure, aimed to reduce the error of the approximate solution provided by the parametric representation. These methods allow us to relate the drift parameter of the periodic orbits to th…
Bounded weak solutions to superlinear Dirichlet double phase problems
2023
AbstractIn this paper we study a Dirichlet double phase problem with a parametric superlinear right-hand side that has subcritical growth. Under very general assumptions on the data, we prove the existence of at least two nontrivial bounded weak solutions to such problem by using variational methods and critical point theory. In contrast to other works we do not need to suppose the Ambrosetti–Rabinowitz condition.
Influence of the quadratic term in the alongwind stochastic response of SDOF structures
1996
A parametric study, regarding the influence of the quadratic pressure term, which is often neglected in the literature, on the stochastic alongwind response of a single-degree-of-freedom (SDOF) structure subjected to wind action, is presented. The results are reported in terms of percentages of difference in the evaluation of the response, by considering and neglecting the quadratic pressure term. The changing parameters considered are: the terrain drag coefficient, the structure height, the structure natural radian frequency, the structure damping coefficient and the wind reference mean velocity. The response stochastic analysis has been carried out in the time domain, by means of the mome…
In vitro activities of antimicrobial agents against Candida species
1999
Objective. Antimicrobial mouthrinses may represent a valid alternative to topical antifungal agents. However, the action of antimicrobials could be affected by the different ingredients incorporated into mouthrinse products. The purpose of the present study was to investigate the in vitro antifungal and fungicidal activities of antimicrobials alone. Study Design. A broth macrodilution method was used to determine the minimum inhibitory concentration of 4 antimicrobial agents against Candida species. Minimum fungicidal concentration was also determined. Results. All antimicrobials showed antifungal activity against all tested organisms, but cetylpyridinium chloride received significantly low…
Development of a Multiparametric Cell-based Protocol to Screen and Classify the Hepatotoxicity Potential of Drugs
2012
Hepatotoxicity is a major reason for drug nonapprovals and withdrawals. The multiparametric analysis of xenobiotic toxicity at the single cells level using flow cytometry and cellular imaging-based approaches, such as high-content screening (HCS) technology, could play a key role in the detection of toxicity and the classification of compounds based on patterns of cellular injury. This study aimed to develop and validate a practical, reproducible, in vitro multiparametric cell-based protocol to assess those drugs that are potentially hepatotoxic to humans and to suggest their mechanisms of action. The assay was applied to HepG2 human cell line cultured in 96-well plates and exposed to 78 di…
Cytometric analysis for drug-induced steatosis in HepG2 cells
2009
Drugs are capable of inducing hepatic lipid accumulation. When fat accumulates, lipids are primarily stored as triglycerides which results in steatosis and provides substrates for lipid peroxidation. An in vitro multiparametric flow cytometry assay was performed in HepG2 cells by using fluorescent probes to analyze cell viability (propidium iodide, PI), lipid accumulation (BODIPY493/503), mitochondrial membrane potential (tetramethyl rhodamine methyl ester, TMRM) and reactive oxygen species generation (ROS) (2',7'-dihydrochlorofluorescein diacetate, DHCF-DA) as functional markers. All the measurements were restricted to live cells by gating the cells that excluded PI or those that exhibited…
Ductility of Reinforced Concrete Members Externally Wrapped with Fiber-Reinforced Polymer Sheets
2007
The effectiveness of external wrapping with fiber-reinforced polymer for enhancing the curvature ductility of lightly reinforced concrete members is investigated. Referring to members with circular transverse cross sections, the performances in terms of both strength and ductility capacities are analyzed, and the predictive reliability of two different recent constitutive models, available in the literature and able to take into account the softening behavior of confined concrete, is checked. A parameter characterizing the effectiveness of the confining wrapping is proposed, and characteristic values are suggested. Moreover, referring to ductility increases due to confinement effects, a com…
Sealing capacity of a photochromatic flowable composite as protective base in nonvital dental bleaching.
2006
Aim To evaluate microleakage of a flowable composite used as a protective isolating base, applied with different adhesive systems. Methodology Seventy root-filled teeth were divided into seven groups. A flowable composite base (Tetric Flow Chroma) was used with three adhesive techniques (Syntac, Excite, Excite DCS; in the three cases with and without acid etching) and in a control group without dentine conditioning or adhesive placement. A 30% hydrogen peroxide solution was applied for 24 h in the pulp chambers, followed by the placement of a dye (silver nitrate) for 4 h. Each tooth was sectioned longitudinally, and examined under 4× magnification to assess the tooth/restoration dye leaka…