Backstepping control of three-phase three-level four-leg shunt active power filter

In this paper, backstepping control for three-level four-leg shunt active power filter (SAPF) system is proposed. The adopted filtering topology requires both a three-dimensional space vector modulation (3DSVM) for controlling the three-level four-leg inverter as well as DC voltage and filter currents control. The regulation of the DC voltage and filter currents is accomplished by backstepping controllers. The voltage-balancing control of two split DC capacitors of the three-level four-leg SAPF is achieved using three-level three-dimensional space vector modulation equipped by a balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The simulation results show the effectiveness of the proposed filtering system in terms of the compensation of the harmonics and the zero sequence current and the operation at unity power factor.Keywords: shunt active power filter; three-dimensional space vector modulation; multilevel four-leg inverter; backstepping control; synchronous reference frame theory

The emotive effect of government branding on citizens’ trust and its boundaries: Does the personal relevance of the policy issue matter?

Recent studies have demonstrated the potency of government branding to enhance citizens’ trust in government organizations and policies. Additionally, studies have pointed to the detrimental implications of this emotive effect, mainly its ability to compensate for organizations’ poor functioning, and accordingly to elicit undue trust. In light of these concerns, this study explores the boundaries of governments’ persuasion of citizens through branding and symbolic communications. Building on social psychology and marketing research, I hypothesize that citizens are less susceptible to persuasion by branding the more they perceive the policy issue as personally relevant. I test this expectation through a survey experiment, focused on air‐pollution policy in Israel, exploiting the natural variation in the perceived personal relevance between citizens residing in a polluted area in the country and others. The results indicate that even high levels of perceived personal relevance do not attenuate the effect of symbolic brand elements. This entails that the boundaries of persuasion and manipulation through branding are wider than expected.The politics and administration of institutional chang

Preservation du concentre de tomate par un agent antifongique (Huile essentielle du citron)

Les huiles essentielles ont des molécules naturelles considérées comme antioxydants, antimicrobiens servant comme conservateur naturel pour préserver l’aliment des différentes altérations. Cette étude a pour objectifs de valoriser les écorces de Citrus limon de la variété « Euréka » par extraction de ses huiles essentielles, d’évaluer in vitro l’activité antifongique de ces huiles extraites par deux modes: hydrodistillation (HEH) et pression à froid (HEP), et enfin les appliquer au concentré de tomate. Le rendement moyen en huile essentielle extraite par hydrodistillation est de 2,20±0,773% et celui de l’huile extraite par pression à froid est de 0,87±0,025%. La composition de ces huiles a été analysée par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC/MS). Les résultats nous ont permis d’identifier 30 constituants représentant 97,81% et 97,42% de l’huile essentielle totale HEH et de celle de HEP, respectivement. Les composants principaux étaient le limonène suivi du α-pinèneet de γ-terpinène. Le test de l’activité antifongique des huiles essentielles du citron a été réalisé par la méthode des aromatogrammes et a montré que cette huile possède une activité antifongique plus au moins intéressante. Les concentrations minimales inhibitrices (CMI) ont été estimées par la méthode de dilution d’agar. Les souches fongiques telles que Aspergillus terreus, Aspergillus niger, Aspergillus flavus, Trichoderma  longibrachiatum, Fusarium oxysporum et Fusarium culmorum ont révélé une nette sensibilité vis-à-vis des huiles extraites avec des CMIs qui varient entre 350 et 600 μg.ml-1 pour HEH et entre 180 à 500μg.ml-1 pour HEP. Ces résultats ont été confirmés par l’application des huiles HEH et HEP au concentré de tomate qui a présenté une meilleure résistance à la contamination fongique par rapport au témoin (sans huiles essentielles) révélant une modification de lacouleur (le rouge vire vers le marron). L’application de ces huiles essentiellesau concentré de tomate nous a permis de déduire que cette huile limite l’altération par les moisissures et le conserve un peu longtemps (deux mois). Essential oils have natural molecules considered as antioxidants, and antimicrobial substances serving as natural preservatives used to preserve the food from various alterations. The objectives of this study were to enhance the use of Citrus limonpeel of the "Eureka" variety by extracting its essential oils, to evaluate in vitro the antifungal activity of these oils extracted by two methods: hydrodistillation (HEH) and cold pressure (HEP), and finally apply them to the tomato concentrate in order to see their effect on fungi (molds). The average yield of essential oil extracted by hydrodistillation is 2.20 ± 0.773% and that of the oil extracted by cold pressing is 0.87 ± 0.025%. The composition of these oils was analyzed by gas chromatography coupled with mass spectrometry (GC / MS). The results allowed us to identify 30 constituents representing 97.81% and 97.42% of the total essential oil HEH and that of HEP, respectively. The main components were limonene followed by α-pinene and γ-terpinene. The test of the antifungal activity of essential oils of lemon has been carried out by the aromatogrammes method; it showed that this oil has an antifungal activity. Minimum inhibitory  concentrations (MIC) were estimated by the agar dilution method. The fungal strains (molds) Aspergillus terreus, Aspergillus niger, Aspergillus flavus, Trichoderma longibrachiatum, Fusarium oxysporum and Fusarium culmorum revealed sensitivity to extracted oils with MICs that vary between 350 and 600 μg.ml-1 for HEH and between 180 and 500 μg.ml-1 for HEP. These results were confirmed by the application of HEH and HEP oils to tomato concentrate, which showed better resistance to fungal contamination compared to the control (without essential oils) revealing a change in color (red turns to brown). The application of these essential oils to tomato concentrate has allowed us to deduce that this oil limits the damage caused by molds and keeps it safe for about two months

Multi-Dimensional Simulations of Pair-Instability Supernovae

We present preliminary results from multidimensional numerical studies of pair instability supernova (PSN), studying the fluid instabilities that occur in multiple spatial dimensions. We use the new radiation-hydrodynamics code, CASTRO, and introduce a new mapping procedure that defines the initial conditions for the multidimensional runs in such a way that conservation of physical quantities is guaranteed at any level of resolution.Comment: Accepted for publication in Computer Physics Communications. 3 pages. 2 fig

Carbon-poor stellar cores as supernova progenitors

Exploring stellar models which ignite carbon off-center (in the mass range of about 1.05 - 1.25 Msun, depending on the carbon mass fraction) we find that they may present an interesting SN I progenitor scenario, since whereas in the standard scenario runaway always takes place at the same density of about 2 X 10^9 gr/cm^3, in our case, due to the small amount of carbon ignited, we get a whole range of densities from 1 X 10^9 up to 6 X 10^9 gr/cm^3. These results could contribute in resolving the emerging recognition that at least some diversity among SNe I exists, since runaway at various central densities is expected to yield various outcomes in terms of the velocities and composition of the ejecta, which should be modeled and compared to observations.Comment: 49 pages, 20 figure

Care of Mechanical Ventilated Patients in General Ward: Nurses Perspective

Aim: This study aimed to explore the care of mechanically ventilated patients in general wards from the nurses' perspective.Methodology: A cross-sectional descriptive study using a self administered questionnaire was given to the nurses with a purposive convenient sampling method in adult patients from medical, surgical and isolation units in studied hospital in KSA. Results: 149 participants from general units represents various years of experiences shared their perception on the knowledge and competencies (M= 3.38±.62) the support they received (M= 2.41±.78), their satisfaction and confidence (M= 2.86±.81) and the resources provided (M= 2.44 ±.69) for caring MV patients in their general unit revealed the total mean in each categories were in the state of either neutral or disagree with the items given. The participants admitted that the found themselves are competent in performing suctioning with aseptic technique and ability to identify the possible complications confidently. However the participant concluded that it was inadequate support for them, staffing ratio, equipment and facilities was inappropriate which leads to dissatisfaction and less confident in caring for MV patients.Conclusion: This study concludes that caring for patients in general ward causing dissatisfaction among the staff and place patients in risk. Hospital administration needs to ensure that general ward nurses are trained accordingly, provide adequate staffing ratio, and prepare the physical environment and suitable equipment to care for MV patients in general ward

Analyzing Risk Factors for Brain Damages in a Group of Newborns with High Risk of Neurodevelopmental Sequelae: A Moroccan Study

Abstract The aim of the study is to identify risk factors for occurrence of perinatal brain injury objectified in transfontanellar ultrasound (TFU) in a group of infants with high risk of neurodevelopmental sequelae. It’s a retrospective study, conducted at the neonatal intensive care unit of the Children's Hospital of Rabat, during the period from 1 January to 31 December 2014. Were included newborns hospitalized for a medical condition with intrauterine croissance retardation (ICUR) more than 5 days and have survived. The neurological workup includes TFU made between day 2 and day 5 of life. Data analysis was performed on SPSS 18.0 software. The level of significance was p <0.05.  The percentage of newborns that developed neurological damage to the TFU was 36%. Patients with abnormalities in the TFU had a breakdown time, duration dependence of O2, duration of hospitalization and a higher frequency of nosocomial infections than patients without abnormality. The interest in the prevention of nosocomial infections is to try to shorten the duration of invasive ventilation, favoring fast relay noninvasive ventilation. Keywords: brain injury; newborns; prematurity, neurodevelopmental sequelae, trans-fontanellar ultrasound.

Syndrome de Shah Waardenberg : à propos d’un cas

Introduction : Le syndrome de Waardenburg-Shah (SWS) est une neurocristopathie caractérisée par l'association d’une surdité neurosensorielle, anomalies de la pigmentation et d'une maladie de Hirschsprung. Nous rapportons le cas d’un nouveau né.Observation : nouveau né de sexe féminin, admis à son 3éme jour de vie pour  un syndrome occlusif. L’examen clinique a objectivé  une mèche de chevaux frontale blanche avec un pli de déshydratation pâteux et un ballonnement abdominal. L’épreuve à la sonde était positive. L’ASP a montré des niveaux hydroaériques coliques et gréliques. Le bilan malformatif n’a pas objectivé d’autres anomalies.Conclusion : Le syndrome de Shah Waardenburg est une affection rare dont le pronostic reste celui de la maladie d’Hershprung

High Latitude Radio Emission in a Sample of Edge-On Spiral Galaxies

We have mapped 16 edge-on galaxies at 20 cm using the VLA. For 5 galaxies, we could form spectral index, energy and magnetic field maps. We find that all but one galaxy show evidence for non-thermal high latitude radio continuum emission, suggesting that cosmic ray halos are common in star forming galaxies. The high latitude emission is seen over a variety of spatial scales and in discrete and/or smooth features. In general, the discrete features emanate from the disk, but estimates of CR diffusion lengths suggest that diffusion alone is insufficient to transport the particles to the high latitudes seen (> 15 kpc in one case). Thus CRs likely diffuse through low density regions and/or are assisted by other mechanisms (e.g. winds). We searched for correlations between the prevalence of high latitude radio emission and a number of other properties, including the global SFR, supernova input rate per unit star forming, and do not find clear correlations with any of these properties.Comment: 40 pages of text, 3 figures, 6 tables, and an appendix of 21 jpeg figures (which is a radio continuum catalogue of 17 galaxies). to appear in A. J. (around January 1999