Donor-Acceptor Complexes of N-Substituted Anilines with Aromatic Nitro Compounds Preparation & Infrared Spectroscopic Investigation

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Hybrid Generators-based AC Microgrid Performance Assessment in Island Mode

Achieving an accurate steady-state averaged active power sharing between parallel inverters in islanded AC microgrids could be realized by a traditional droop control. For identical inverters having the same droop gains, it is assumed that the transient average power responses will be similar, and no circulating current will flow between the units. However, different line impedances could influence the instantaneous power significantly and thus circulating power flows among the inverters particularly during sudden disturbances such as load changes. This power, if absorbed by an inverter, will lead the DC link voltage to rise abruptly and trip the inverter, thus, degrading the performance of the whole microgrid. The problem becomes worse when hybrid generators are serving as unidirectional power source. This paper assesses the performance of hybrid generators within an islanded microgrid against the mismatch in line impedances. Two schemes to stabilize the microgrid are proposed. In addition, a participation factor analysis is developed to select the most effective controller scheme to bound the DC link voltage and minimize the circulating power. Simulation and experimental results are presented to verify the analysis and the capability of the proposed controller

Le s symbioses fixatrices d’azote : types et régulateurs t ranscriptionnels de la nodulation

Les symbioses fixatrices d’azote sont des interactions à bénéfice réciproque entre certaines espèces végétales (légumineuses et plantes actinorhiziennes principalement) et des microorganismes du sol ( r hizobium ou Frankia ). Ces symbioses contribuent de façon considérable à la nutrition azotée de ces plantes e t donc à leur développement particulièrement sur l es sols pauvres en azote . L’établissement de ces symbioses démarre par un dialogue moléculaire , puis par la formation de structures appelées nodules ou nodosités , siège des échanges entre les deux partenaires (plante et bactérie) La formation et le développement de nodules requièrent la médiation de gènes spécifiques parmi les quels figurent les régulateurs transcriptionnels ( facteurs de transcription et microARN) microARN). Des facteurs de transcription dont CYCLOPS, NSP1 et NSP2 communs entre les symbioses r hizobium légumineuse et Frankia plante actinorhizienne ont été caractérisés à d ifférents stades du développement du nodule Ils interagissent avec les protéines DE LLA pour induire l’expression du gène NIN , n écessaire à l’initiation de l’infection . Ces facteurs de transcription sont régulés par divers microARN. Cette revue résume l es types de symbioses fixatrices d’azote et les récentes avancées sur l es régulateurs transcriptionnels impliqué s dans l es étapes de pré infection, d’infection et d’organogenèse du nodule . Pour ce faire, nous avons collecté et analysé des données pertinentes de la littérature sur des études moléculaires et cellulaires des symbioses fixatrices d’azote

Ultraviolet and Infrared Spectra of Some p-Nitrobenzyl Phenyl Ethers

The UV-spectra of substituted p-nitrobenzyl phenyl ethers in ethanol and carbon tetrachloride were recorded. The effect of substitution on band position and intensity is correlated with the electronic nature of the group. The IR-spectra are analysed and the position of certain bands ii;; dis.cussed in terms of molecular structure

The Reddest DR3 SDSS/XMM Quasars

We have cross-correlated the SDSS DR3 Schneider et al. (2005) quasar catalog with the XMM-Newton archive. Color and redshift selections (g - r > 0.5 and 0.9 z < 2.1) result in a sample of 17 red, moderate redshift quasars. The redshift selection minimizes possible contamination due to host galaxy emission and Lyalpha forest absorption. Both optical and X-ray information are required to distinguish between the two likely remaining causes of the red colors: 1) dust-reddening and 2) an intrinsically red continuum. We find that 7 of 17 quasars can be classified as probable `intrinsically red' objects. These 7 quasars have unusually broad MgII emission lines (=10,500 km s^{-1}), moderately flat, but unabsorbed X-ray spectra =1.66+/-0.08), and low accretion rates (mdot/mdot_{Edd}} ~ 0.01). We suggest low accretion rates as a possible physical explanation for quasars with intrinsically red optical continua. We find that 8 of 17 quasars can be classified as dust-reddened. Three of these have upper-limits on the absorption column from X-ray spectral fits of N_H = 3-13 x 10^{22} cm^2, while the other five quasars must be absorbed by at least N_H = 10^{23} cm^2 in order to be consistent with a comparably selected alpha_{ox}-l_{uv} distribution. Two objects in the sample are unclassified.Comment: 20 pages, 12 figures, Accepted for publication in Ap

Adrenal lesions found incidentally: how to improve clinical and cost-effectiveness

Introduction Adrenal incidentalomas are lesions that are incidentally identified while scanning for other conditions. While most are benign and hormonally non-functional, around 20% are malignant and/or hormonally active, requiring prompt intervention. Malignant lesions can be aggressive and life-threatening, while hormonally active tumours cause various endocrine disorders, with significant morbidity and mortality. Despite this, management of patients with adrenal incidentalomas is variable, with no robust evidence base. This project aimed to establish more effective and timely management of these patients. Methods We developed a web-based, electronic Adrenal Incidentaloma Management System (eAIMS), which incorporated the evidence-based and National Health Service–aligned 2016 European guidelines. The system captures key clinical, biochemical and radiological information necessary for adrenal incidentaloma patient management and generates a pre-populated outcome letter, saving clinical and administrative time while ensuring timely management plans with enhanced safety. Furthermore, we developed a prioritisation strategy, with members of the multidisciplinary team, which prioritised high-risk individuals for detailed discussion and management. Patient focus groups informed process-mapping and multidisciplinary team process re-design and patient information leaflet development. The project was partnered by University Hospital of South Manchester to maximise generalisability. Results Implementation of eAIMS, along with improvements in the prioritisation strategy, resulted in a 49% reduction in staff hands-on time, as well as a 78% reduction in the time from adrenal incidentaloma identification to multidisciplinary team decision. A health economic analysis identified a 28% reduction in costs. Conclusions The system’s in-built data validation and the automatic generation of the multidisciplinary team outcome letter improved patient safety through a reduction in transcription errors. We are currently developing the next stage of the programme to proactively identify all new adrenal incidentaloma cases

Metallicities of 0.3<z<1.0 Galaxies in the GOODS-North Field

We measure nebular oxygen abundances for 204 emission-line galaxies with redshifts 0.3<z<1.0 in the Great Observatories Origins Deep Survey North (GOODS-N) field using spectra from the Team Keck Redshift Survey (TKRS). We also provide an updated analytic prescription for estimating oxygen abundances using the traditional strong emission line ratio, R_{23}, based on the photoionization models of Kewley & Dopita (2003). We include an analytic formula for very crude metallicity estimates using the [NII]6584/Halpha ratio. Oxygen abundances for GOODS-N galaxies range from 8.2< 12+log(O/H)< 9.1 corresponding to metallicities between 0.3 and 2.5 times the solar value. This sample of galaxies exhibits a correlation between rest-frame blue luminosity and gas-phase metallicity (i.e., an L-Z relation), consistent with L-Z correlations of previously-studied intermediate-redshift samples. The zero point of the L-Z relation evolves with redshift in the sense that galaxies of a given luminosity become more metal poor at higher redshift. Galaxies in luminosity bins -18.5<M_B<-21.5 exhibit a decrease in average oxygen abundance by 0.14\pm0.05 dex from z=0 to z=1. This rate of metal enrichment means that 28\pm0.07% of metals in local galaxies have been synthesized since z=1, in reasonable agreement with the predictions based on published star formation rate densities which show that ~38% of stars in the universe have formed during the same interval. (Abridged)Comment: AASTeX, 49 pages, 16 figures, accepted for publication in The Astrophysical Journa