19,579 research outputs found
Detection of a variable ultra-fast outflow in the Narrow Line Seyfert 1 galaxy PG 1448+273
Relativistically blueshifted absorption features of highly ionised ions, the
so-called ultra-fast outflows (UFOs), have been detected in the X-ray spectra
of a number of accreting supermassive black holes. If these features truly
originate from accretion disc winds accelerated to more than 10 per cent of the
speed of light, their energy budget is very significant and they can contribute
to or even drive galaxy-scale feedback from active galactic nuclei (AGN).
However, the UFO spectral features are often weak due to high ionisation of the
outflowing material, and the inference of the wind physical properties can be
complicated by other spectral features in AGN such as relativistic reflection.
Here we study a highly accreting Narrow Line Seyfert 1 galaxy PG 1448+273. We
apply an automated, systematic routine for detecting outflows in accreting
systems and achieve an unambiguous detection of a UFO in this AGN. The UFO
absorption is observed in both soft and hard X-ray bands with the XMM-Newton
observatory. The velocity of the outflow is (26900 +- 600) km/s (~0.09c), with
an ionisation parameter of log ({\xi} / erg cm s^-1)=4.03_{-0.08}^{+0.10} and a
column density above 10^23 cm^-2. At the same time, we detect weak warm
absorption features in the spectrum of the object. Our systematic outflow
search suggests the presence of further multi-phase wind structure, but we
cannot claim a significant detection considering the present data quality. The
UFO is not detected in a second, shorter observation with XMM-Newton,
indicating variability in time, observed also in other similar AGN.Comment: Accepted for publication in MNRAS. 14 pages, 11 figures, 1 tabl
Easy and accurate estimation of grapevine leaf area with simple mathematical models
Empirical models for non-destructive estimation of primary and lateral leaf area are presented for cv. Aragonez, syn. Tempranillo. Primary leaf area of shoots is estimated by a model using a calculated variable obtained from the average of the largest and smallest primary leaf area multiplied by the number of primary leaves. For lateral leaf area estimation another model is presented which uses the same type of calculated variable plus the area of the largest leaf. Both models explain a high proportion of the leaf area variability and have a good predicting capability. Validation with 4 independent data sets periodically sampled during several seasons from different varieties shows that these models can predict primary and lateral leaf area independently of variety, year and growth stage, using a non-destructive, low cost, simple and accurate method. The models represent a powerful tool for grapevine research, for consultants and advanced growers allowing the evaluation of leaf area more frequently.
Probing BH mass and accretion through X-ray variability in the CDFS
Recent work on nearby AGNs has shown that X-ray variability is correlated
with the mass and accretion rate onto the central SMBH. Here we present the
application of the variability-luminosity relation to high redshift AGNs in the
CDFS, making use of XMM-Newton observations. We use Monte Carlo simulations in
order to properly account for bias and uncertainties introduced by the sparse
sampling and the very low statistics. Our preliminary results indicate that BH
masses span over the range from 10^5 to 10^9 solar mass while accretion rates
range from 10^-3 up to values greater than 1, in unit of Eddington accretion
rate.Comment: 2 pages, 2 figures,in press in the X-ray 2009 Conference Proceedings
(Bologna, 7-11 September 2009
Desgaste dentario e ingestión de partículas minerales en osos actuales y extintos del Norte de España
[Abstract] The dental morphology of the cave bear Ursus spelaeus (Rosenmuller & Heinroth, 1794) indicates its specialisation as a vegetation eater. Although vegetal matter plays also an important role in the diet of most living bears, the dental wear exhibited by cave bears differs qualitatively from that seen in brown bears even on gross inspection. The diet of the extant brown bear Ursus arctos (Linnaeus, 1758) is well known from present-day stu-dies involving direct observation as well as scat analysis. The ingestion of tubers and other gritty foods has repeatedly been suggested as the cause for the extreme wear observed on cave bear teeth. In this work we seek to analyse the modes and degrees of enamel-wear in brown and cave bears from Northern Spain with the objective of shedding some light on the cave bear diet as regards to grit ingestion. We examine the incidence of gross wear features and enamel micro-fractures on the bear molars, and from this it is concluded that the cave bears analysed here did not ingest gritty foods and seemed to avoid putting into their mouth any object at all soiled with gritty dirt
Elaboração e caracterização de fruta estruturada mista de goiaba e cajá.
O objetivo deste trabalho é estabelecer procedimento tecnológico para produção de fruta estruturada mista a partir de polpa de goiaba e cajá, unindo-se as propriedades sensoriais e nutritivas de cada uma das frutas ao produto final. Avaliou-se o efeito de diferentes proporções de polpa de goiaba e cajá nas características físico-químicas e sensoriais do produto final. Os hidrocoloides utilizados para a formação do gel foram: pectina, gelatina e alginato de sódio. Foram realizadas avaliações físicoquímicas nos frutos in natura e nos estruturados obtidos, além da análise de aceitação e a intenção de compra do produto final. Os resultados mostram ser possível produzir fruta estruturada com alta concentração de polpas de cajá e goiaba. Sensorialmente os produtos obtidos apresentaram médias de aceitação elevadas, indicando potencial de consumo na forma apresentada, sendo considerados produtos de conveniência, além de saudáveis, tendo em vista seus teores significativos de vitamina C e carotenoides totais
Infectious disease screening outcomes and reducing barriers to care for unaccompanied asylum-seeking children: a single centre retrospective clinical analysis
Objective: Evaluate the Unity Clinic’s infectious disease screening programme for unaccompanied asylum-seeking children (UASC), calculate rates of infection and identify further health needs. Design: Retrospective audit of electronic patient data. Setting and patients UASC who attended the Unity Clinic between 1 November 2019 and 22 March 2022. Main outcome measures: Baseline demographics, social, mental health and journey details, infection screening and investigation results. Results: 155 UASC were reviewed: 89% (138 of 155) male, median age 17 years (IQR 16–17). Most frequent countries of origin were Sudan, Eritrea and Afghanistan. Median duration of travel to the UK (n=79) was 2 years (IQR 0.5–4); 35.6% (47 of 132) arrived by boat and 54.5% (72 of 132) by road. 44.8% (69 of 154) had one or more positive infection screening results: 22.7% (35 of 154) and 1.3% (2 of 154) positive for latent and active tuberculosis, respectively; 4.6% (7 of 152) chronic active hepatitis B and 17.1% (26 of 152) for past infection; 1.3% (2 of 154) for HIV; 13.0% (19 of 146) for Strongyloides. There were three cases of syphilis (n=152; 2.0%) and one chlamydia (n=148; 0.7%)—none of whom disclosed prior sexual activity during screening. 39.6% (61 of 154) and 27.9% (43/154) reported disturbances to mood or sleep, respectively. 55.2% (85 of 154) disclosed traumatic incidents during and/or prior to their journey, including physical and sexual assault. Conclusions: The Unity Clinic provides a thorough infectious disease screening service for UASC following national guidance. Results highlight the need for universal, non-judgemental screening for sexually transmitted infections, as targeted screening would not identify positive cases. High rates of well-being issues and previous abuse emphasise the need for multidisciplinary, collaborative approaches to care
Insights on the use of wind speed vertical extrapolation methods
The present work aims to study the influence of
using different methods for wind speed extrapolation in energy
production calculations. A dataset of 21 meteorological masts
from several landscape characteristics and locations, with at least
one year of 10-minute wind speed/direction data, was used as the
basis for calculations. Both the power law through estimation of
wind shear coefficients, and the logarithmic-based profile using
WAsP, were used as mathematical models for predicting wind
shear. Wind speed extrapolation was performed either from the
top-most height, using a distance method that incorporated all
measurement heights, or using the function for wind shear
coefficient prediction. It was found that using the logarithmicbased
profile was the less reliable of all studied methods. The
study showed that the most accurate method was the power law
with wind shear coefficients estimated from the two upper
heights closest to the extrapolation height, by wind direction
sector of 30º, and the wind speeds extrapolation from the topmost
height of the two. It is suggested that the use of this method
reduces uncertainty in AEP estimates.info:eu-repo/semantics/publishedVersio
The motion of two masses coupled to a massive spring
We discuss the classical motion of a spring of arbitrary mass coupled to two
arbitrary massive blocks attached at its ends. A general approach to the
problem is presented and some general results are obtained. Examples for which
a simple elastic function can be inferred are discussed and the normal modes
and normal frequencies obtained. An approximation procedure to the evaluation
of the normel frequencies in the case of uniform elastic function and mass
density is also discussed.Comment: Standard Latex file plus three eps figure
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