Search results for "Methods"
showing 10 items of 4526 documents
A dissipated energy comparison to evaluate fatigue resistance using 2PB
2012
Flexural fatigue due to repeated traffic loading is a process of cumulative damage and one of the main failure modes of flexible pavement structures. Typically, micro-cracks originate at the bottom of an asphalt concrete layer due to horizontal tensile strains. Micro-cracking starts to propagate towards the upper layers under repeated loading which can lead to pavement failure. Different approaches are usually used to characterise fatigue resistance in asphalt mixtures including the phenomenological approach, the fracture mechanics approach and the dissipated energy approach. This paper presents a comparison of fatigue resistance calculated for different dissipated energy models using 2 Poi…
Spectrophotometric determination of promethazine by flow injection analysis and oxidation by CeIV
1992
A flow injection analysis (FIA) procedure is proposed for the determination of promethazine. The sample solution is directly injected into the carrier-reagent stream which comprises a solution of ceric ions in a sulphuric acid medium. The absorbance at 514 nm from the red colour developed by the oxidation of promethazine is measured. Effects of foreign substances have been investigated and the procedure has been applied to the determination of promethazine in a pharmaceutical formulation (tablets).
Stability in a System subject to Noise with Regulated Periodicity
2011
The stability of a simple dynamical system subject to multiplicative one-side pulse noise with hidden periodicity is investigated both analytically and numerically. The stability analysis is based on the exact result for the characteristic functional of the renewal pulse process. The influence of the memory effects on the stability condition is analyzed for two cases: (i) the dead-time-distorted poissonian process, and (ii) the renewal process with Pareto distribution. We show that, for fixed noise intensity, the system can be stable when the noise is characterized by high periodicity and unstable at low periodicity.
Two competing species in super-diffusive dynamical regimes
2010
The dynamics of two competing species within the framework of the generalized Lotka-Volterra equations, in the presence of multiplicative alpha-stable Lévy noise sources and a random time dependent interaction parameter, is studied. The species dynamics is characterized by two different dynamical regimes, exclusion of one species and coexistence of both, depending on the values of the interaction parameter, which obeys a Langevin equation with a periodically fluctuating bistable potential and an additive alpha-stable Lévy noise. The stochastic resonance phenomenon is analyzed for noise sources asymmetrically distributed. Finally, the effects of statistical dependence between multiplicative …
Noise enhanced stability in fluctuating metastable states Phys. Rev. E69, 061103 (2004)
2004
We derive general equations for the nonlinear relaxation time of Brownian diffusion in randomly switching potential with a sink. For piece-wise linear dichotomously fluctuating potential with metastable state, we obtain the exact average lifetime as a function of the potential parameters and the noise intensity. Our result is valid for arbitrary white noise intensity and for arbitrary fluctuation rate of the potential. We find noise enhanced stability phenomenon in the system investigated: The average lifetime of the metastable state is greater than the time obtained in the absence of additive white noise.We obtain the parameter region of the fluctuating potential where the effect can be ob…
Anti-angiogenic drug loaded liposomes: Nanotherapy for early atherosclerotic lesions in mice.
2018
Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190540 También participan en la elaboración de este artículo científico: Aracely Calatayud-Pascual, Alicia López-Castellano, Elena P. Albelda, Enrique García-España, Luis Martí-Bonmatí, Juan C. Frias y M. Teresa Albelda. Fumagillin-loaded liposomes were injected into ApoE-KO mice. The animals were divided into several groups to test the efficacy of this anti-angiogenic drug for early treatment of atherosclerotic lesions. Statistical analysis of the lesions revealed a decrease in the lesion size after 5 weeks of treatment.
An experiment to study the structure of the focal volume in apertured focusing systems
2001
We present a simple experiment, specifically designed for students of undergraduate optics courses, where the influence of an aperture stop position on the three-dimensional structure of the focal volume of focusing systems is studied. The experiment, which involves only simple optical elements, permits an undergraduate student to generate different focal structures by simply axially displacing the aperture stop.
Guest Editorial: Advanced Motion Control for Mechatronic Applications With Precision and Force Requirements
2021
The articles in this special section focus on advanced motion control for mechatronic applications with precision and force requirements. Motion control is concerned with all the issues arising in the control of the movement of a physical device. This means that MC is not limited to the use of proper devices for sensing and actuation, in addition to suitable control algorithms, but it also deals with all the possible interactions of the controlled devices with the environment. This is the most remarkable aspect of MC, nowadays deployed in numerous mechatronic systems, especially those which are dynamically acting in heterogenous, time-varying, active, and human-accessible environments. With…
Nano- and microplastic analysis: Focus on their occurrence in freshwater ecosystems and remediation technologies
2019
Plastic pollution is a global problem since 2016 when its production reached 322 million tonnes, excluding fibers. Daily discharges of microplastics (MPs, defined as <5 mm in size) are estimated in the range of 50,000 up to 15 million particles, whereas no information on nanoplastic (NP, <100 nm) release is available yet. Different processes further degraded these materials producing more MPs and NPs. This review attempts to fill the void of information on the state-of-art analysis of MPs and NPs (recently identified as emerging contaminants) and provides a critical overview on modern instrumentation, newly developed workflows, and promising techniques for their characterization (Raman and …
High Pressure Treatment Effect on Physicochemical and Nutritional Properties of Fluid Foods During Storage: A Review
2012
Abstract: Consumers demand foods that are easy to consume and that are of high nutritional and sensory quality. Therefore, they appreciate the similarity of minimally processed products to fresh products. In recent years, the food industry has shown increased interest in nonthermal preservation technologies, because they provide products of proven quality and can be an alternative to traditional thermal methods, thus increasing added value. This review examines the effects of high pressure processing (HPP) on the nutritional and physicochemical parameters of fluid foods. While some general trends can be observed, the effects of HPP differ not only according to treatment intensity, but also…