Analysis of Stationary- and Synchronous-Reference Frames for Three-Phase Three-Wire Grid-Connected Converter AC Current Regulators

The current state of the art shows that unbalance and distortion on the voltage waveforms at the terminals of a grid-connected inverter disturb its output currents. This paper compares AC linear current regulators for three-phase three-wire voltage source converters with three different reference frames, namely: (1) natural (abc), (2) orthogonal stationary (αβ), and (3) orthogonal synchronous (dq). The quantitative comparison analysis is based on mathematical models of grid disturbances using the impedance-based analysis, the computational effort assessment, as well as the steady-state and transient performance evaluation based on experimental results. The control scheme devised in the dq-frame has the highest computational effort and inferior performance under negative-sequence voltage disturbances, whereas it shows superior performance under positive-sequence voltages among the reference frames evaluated. In contrast, the stationary natural frame abc has the lowest computational effort due to its straightforward implementation, with similar results in terms of steady-state and transient behavior. The αβ-frame is an intermediate solution in terms of computational cost.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Identification of potential sources of airborne 0lea pollen in the southwest Iberian Peninsula

Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop

Effect of non-thermal processing on the aromatic profile of Cantaloupe melon juice

info:eu-repo/semantics/acceptedVersio

Random graph states, maximal flow and Fuss-Catalan distributions

For any graph consisting of $k$ vertices and $m$ edges we construct an ensemble of random pure quantum states which describe a system composed of $2m$ subsystems. Each edge of the graph represents a bi-partite, maximally entangled state. Each vertex represents a random unitary matrix generated according to the Haar measure, which describes the coupling between subsystems. Dividing all subsystems into two parts, one may study entanglement with respect to this partition. A general technique to derive an expression for the average entanglement entropy of random pure states associated to a given graph is presented. Our technique relies on Weingarten calculus and flow problems. We analyze statistical properties of spectra of such random density matrices and show for which cases they are described by the free Poissonian (Marchenko-Pastur) distribution. We derive a discrete family of generalized, Fuss-Catalan distributions and explicitly construct graphs which lead to ensembles of random states characterized by these novel distributions of eigenvalues.Comment: 37 pages, 24 figure

THE HIALINE PROJECT: ALLERGEN RELEASE FROM POLLEN ACROSS 10 EUROPEAN COUNTRIES

Exposure to allergens is one of severa1 factors determining sensitization and allergic symptoms in individuals. Exposure to aeroallergens from pollen is assessed by counting allergenic pollen in ambient air. However, proof is lacking that pollen count is representative for allergen exposure. We therefore monitored simultaneously birch, grass and olive pollen counts and their corresponding major pollen allergens Bet v 1, Phl p 5 and Ole e 1 across Europe. Already at one location in Europe in Munich, Germany, it has been found that the same amount of pollen from different years, different trees and even different days released up to lO-fold different amounts of Bet v 1. Thus exposure to allergen is poorly monitored by only monitoring pollen countl-2. Monitoring the allergen itself in ambient air might be an improvement in allergen exposure assessment. The objective of the HIALINE-project is to evaluate if these effects found in Munich, Germany are also measurable over a bigger geographic area like Europe, and at the same time implement an outdoor allergen early warning network, in addition to the pollen forecasts. Climatic factors that influence allergen exposure will be extracted and will be used to calculate the effect of climate change on local airborne allergen exposure. The major allergens from the top 3 airborne allergens in Europe (grasses, birch and olive) are sampled with a cascade impactor, extracted and analyzed by allergen specific ELISA 's. Pollen counts are measured by standard pollen traps and correlated with the weather data. Allergen forecast will be calculated by incorporating the SILAM chemical transport model and compared with the observations of HIALINE aiming at a comprehensive parameterization of the allergen release and transport. Expected outcomes are the implementation of a network of European outdoor allergen measurements to better predict allergic symptoms. Also the climatic factors that govern allergen exposure in outdoor air will be established. These can be used to calculate the effect of climate change on the health effects of airborne allergens The research leading to these results has received funding from the Executive Agency for Health and Consumers under grant agreement No 2008 11 07

The European project HIALINE (Health Impacts of Airborne Allergen Information Network): results of pollen and allergen of Betula monitoring in Parma (2009)

Introduction. Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content in ambient air is unknown. HIALINE therefore monitored atmospheric concentrations of Betula, Poaceae and Olea pollen grains and matched their major allergens Bet v1, Phl p5 and Ole e1 across Europe. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. New knowledge through the use of new experimental approaches in the field of aerobiological monitoring will enable better in the prevention and clinical management of pollinosis. In order to disseminate the knowledge of the project we present the results of first year of birch pollen grains and the matched major pollen allergen Bet v1 monitored in Parma (UNIPR), Italy with a short reference to the results obtained by the other participants and about developing models of dissemination and forecasts of pollen and allergens. Materials and methods. The pollen was sampled by a Hirst pollen trap. Allergens was collected with a CHEMVOL® high-volume cascade impactor, extracted from pollen and quantified by ELISA. Antibodies for analysis of Bet v1 are delivered by the industrial partner in this project. Quality control has been carried out for the monitoring pollen activities and allergen concentrations. Results. The project has highlighted that it is possible also to measure pollen allergen in ambient air in different European areas. The results obtained from the center of Parma and other European partners have highlighted the different allergenic powers of pollen of Betula, in different geographical areas. Moreover, daily in each area the allergenic power of pollen grains was very variable. Discussion. HIALINE has been a very important project to understand the mechanisms of sensitization, clinical management of pollinosis and to improve immunotherapy towards a tailored immunotherapy. The results of the project will help medical doctors, authorities and patients, to better manage the different aspects related to pollinosis