Search results for "Analytical methods"
showing 10 items of 15 documents
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…
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…
School Staff-centered School Development by Communicative Action: Working Methods for Creating Collective Responsibility - From the Idea to Action
2020
School development is often seen as a concerted (re-)action to educational policies, curriculum development, and change in education laws or regulations, and sometimes, as stakeholders’ reactions to low school performance. Generally, school development incorporates organizational, managerial, and educational activities and measures. This is done to adapt to the new situation to achieve the desired changes and goals initiated by a given curriculum reform. In contrast, this paper focuses on school staff–driven development: It describes how teachers together with paraprofessionals contribute to school-development. Using collective responsibility creating working methods of communication, the e…
Metaproteomic analysis of atmospheric aerosol samples.
2016
Metaproteomic analysis of air particulate matter provides information about the abundance and properties of bioaerosols in the atmosphere and their influence on climate and public health. We developed and applied efficient methods for the extraction and analysis of proteins from glass fiber filter samples of total, coarse, and fine particulate matter. Size exclusion chromatography was applied to remove matrix components, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was applied for protein fractionation according to molecular size, followed by in-gel digestion and LC-MS/MS analysis of peptides using a hybrid Quadrupole-Orbitrap MS. Maxquant software and the Swiss-…
Enhancing Metastability by Dissipation and Driving in an Asymmetric Bistable Quantum System.
2018
The stabilizing effect of quantum fluctuations on the escape process and the relaxation dynamics from a quantum metastable state are investigated. Specifically, the quantum dynamics of a multilevel bistable system coupled to a bosonic Ohmic thermal bath in strong dissipation regime is analyzed. The study is performed by a non-perturbative method based on the real-time path integral approach of the Feynman-Vernon influence functional. We consider a strongly asymmetric double well potential with and without a monochromatic external driving, and with an out-of-equilibrium initial condition. In the absence of driving we observe a nonmonotonic behavior of the escape time from the metastable regi…
A Comprehensive Review on Lipid Oxidation in Meat and Meat Products.
2019
Meat and meat products are a fundamental part of the human diet. The protein and vitamin content, as well as essential fatty acids, gives them an appropriate composition to complete the nutritional requirements. However, meat constituents are susceptible to degradation processes. Among them, the most important, after microbial deterioration, are oxidative processes, which affect lipids, pigments, proteins and vitamins. During these reactions a sensory degradation of the product occurs, causing consumer rejection. In addition, there is a nutritional loss that leads to the formation of toxic substances, so the control of oxidative processes is of vital importance for the meat industry. Noneth…
Synthesis of azoxystrobin transformation products and selection of monoclonal antibodies for immunoassay development
2012
The use of agrochemicals for crop protection may result in the presence of toxic residues in soils and aquatic environments, besides in foodstuffs. Most often just the parent compound is included in the definition of pesticide residue, even though chemicals resulting from biotransformation and degradation routes might also be of toxicological relevance. Azoxystrobin is a broad-spectrum systemic fungicide widely used worldwide to combat pathogenic fungi affecting plants. We herein report the synthesis and detailed chemical characterization of several of the most relevant metabolites and degradates of azoxystrobin. These compounds were further employed as ligands for screening a collection of…