Search results for "Analytical method"
showing 10 items of 30 documents
Analytical design of nonlinear optical loop mirrors for fiber-optic communication systems
2006
International audience; We propose an easy and efficient method for analytically designing nonlinear optical loop mirrors (NOLMs) for fiber-optic communication systems. This analytical design is based on a Taylor series expansion of the transfer function of the NOLM, from which highly stable dynamical regimes can be readily obtained for any desired pulse parameters. We present numerical simulations showing dramatically improved performances in a 160 Gb/s transmission system that incorporates the NOLMs designed analytically.
Analytical Methods Used in Biotransformation Studies of Organophosphonates
2022
This work was supported by the National Science Centre, Poland (NCN) grant number 2017/27/B/NZ4/00698. Among diverse organophosphorus compounds, whose residues are determined in various ecosystems, phosphonates possess special meaning. Regarding their biological activity, capability to chelating metal cations, and stability of direct carbon to phosphorus bond under physiological conditions, phosphonic compounds found many various applications. These compounds are commonly used as pesticides, drugs, anticorrosive agents, and additives to surfactants. Common use of these substances results in an increase in their concentration in various ecosystems which may cause considerable ecological prob…
Microanalytical method for studying paintings by use of fluorescence spectroscopy combined with principal component analysis
2013
Abstract The study of several different naturally aged films of organic painting materials, is described. Materials studied include drying oils (walnut, poppy seed and linseed oil) resin-based paint varnishes (the triterpenoid dammar and the diterpenoids sandarac and turpentine) and protein-based binding media (egg yolk and casein). A not expensive methodology for a rapid identification of binding media and varnishes, that applies principal component analysis (PCA) to Excitation Emission (EE) fluorescence spectra, is proposed. PCA was performed on a data matrix where the rows represent studied materials and columns the variables; the variables include the fluorescence intensities associated…
Environmental Aspect Concerning Phthalates Contamination: Analytical Approaches and Assessment of Biomonitoring in the Aquatic Environment
2023
This review is a survey of recent progress in studies concerning the impact of phthalic acid esters in aquatic organisms. After introducing the classification, properties, sources, fate, and toxic effects related to phthalates, an overview of the techniques of extraction and analysis of these substances is provided. As a result, the general concepts of environmental bioindicators, biomonitoring systems, and other concepts related to phthalate contamination in the aquatic environment are presented. Recent bioaccumulation data of different phthalates are summarised in a table and organised according to the type of organism, tissue, and geographical area of sampling. Bioindicator organisms tha…
Selective Harmonic Elimination in a 5-Level Single Phase Converter with FPGA Based Controller
2018
Multilevel converters are becoming popular in high-power applications such as motor drives, renewable energy systems and distribution systems. Among all modulation techniques, selective harmonic elimination methods offer high quality voltage waveforms with operations at low switching frequency, hence, they are especially suitable for high-power applications. In this paper, a new analytical expression for the SHE problem formulated for a five-level converter is introduced, which is able to calculate the exact value of the switching angles. After a mathematical description of the proposed approach, this manuscript reports simulation and experimental results and analysis showing achievable res…
Analysis of emerging contaminants and nanomaterials in plant materials following uptake from soils
2017
The reuse of treated wastewater or wastewater-impacted river water is growing, particularly in arid areas, due to the climate change. As well, the disposal of sludges, biosolids or biochar as soil amendments to improve agricultural output is widely implemented in the EU. These practices can be a source of emerging contaminants and engineering nanomaterials (ENMs) to the environment and condition their incorporation to food chain that could affect human beings. This review covers current analytical techniques, instruments and methodologies used to determine emerging contaminants and ENMs from irrigation water and/or soil amendments in plants. Trends regarding sample treatment, separation and…
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 …
Volatiles in pantellerite magmas: A case study of the Green Tuff Plinian eruption (Island of Pantelleria, Italy)
2013
Abstract The Green Tuff (GT) Plinian eruption, the largest in magnitude at Pantelleria, erupted 3 to 7 km3 DRE of pantellerite magma and a small volume of trachyte. Fifty-nine anorthoclase-hosted melt inclusions from the two basal pumice members were analyzed by FT-IR spectroscopy in order to assess the pre-eruptive H2O content in the pantellerite melt. Microanalytical methods were used to determine major element, Cl, F and S contents. Melt inclusions and glassy groundmasses have a nearly homogeneous pantelleritic composition (peralkaline index = 1.9-2.2) and variable water contents ranging from 1.4 to as high as 4.2 wt %, i.e. much higher than the 1.4 wt % of earlier published studies. The…
Ferrocenyl glycopeptides as electrochemical probes to detect autoantibodies in multiple sclerosis patients' será
2008
Abstract Glycopeptide analogues of CSF114(Glc), modified at N-terminus with new ferrocenyl carboxylic acid and a new ferrocenyl-thiphosphino amino acid, were used to implement a new electrochemical biosensor for autoantibody detection in multiple sclerosis. The ferrocenyl moiety of these "electrochemical probes" did not affect autoantibody recognition both in SP-ELISA and in inhibition experiments. By electrochemical monitoring the interactions of the modified peptides Fc-CSF114(Glc) and 4-FcPhP(S)Abu-CSF114(Glc) with the autoantibodies, we demonstrated that autoantibodies could be detected with a sensitivity comparable to ELISA method. The new electrochemical probes can be proposed to char…
Electrochemical biosensing using hydrogel nanoparticles
2014
Abstract Biology and medicine have seen great advancements in the development of nanobiosensors capable of characterizing and quantifying biomolecules. This review reports a systematic study of the usefulness of hydrogel nanoparticles (HNPs) in the different steps of the electroanalytical process developed in electrochemical biosensing systems. We illustrate the advantages offered by HNPs in detection of analytes with representative recent examples that highlight the scientific interest in widening the use of HNPs in electrochemical biosensing methods. We review different types of HNP-based electrochemical biosensors, such as enzyme, protein, and nucleic acids, in terms of their sensing per…