Rotor redesign for a highly loaded 1800 ft/sec tip speed fan. 1: Aerodynamic and mechanical design report

A quasi three dimensional design system and multiple-circular-arc airfoil sections were used to design a fan rotor. An axisymmetric intrablade flow field calculation modeled the shroud of an isolated splitter and radial distribution. The structural analysis indicates that the design is satisfactory for evaluation of aerodynamic performance of the fan stage in a test facility

One, two, or three stars? An investigation of an unusual eclipsing binary candidate undergoing dramatic period changes

We report our investigation of 1SWASP J234401.81-212229.1, a variable with a 18 461.6 s period. After identification in a 2011 search of the SuperWASP archive for main-sequence eclipsing binary candidates near the distribution's short-period limit of ~0.20 d, it was measured to be undergoing rapid period decrease in our earlier work, though later observations supported a cyclic variation in period length. Spectroscopic data obtained in 2012 with the Southern African Large Telescope did not, however, support the interpretation of the object as a normal eclipsing binary. Here, we consider three possible explanations consistent with the data: a single-star oblique rotator model in which variability results from stable cool spots on opposite magnetic poles; a two-star model in which the secondary is a brown dwarf; and a three-star model involving a low-mass eclipsing binary in a hierarchical triple system. We conclude that the latter is the most likely model

Follow Up of Transiting Hot Jupiters with the OpenScience Observatories

We have been using the Open University OpenScience Observatories (OSO) to undertake follow up observations of known transiting hot Jupiters for the past three years. Here we present recent system characterisation and transit timing results for WASP-52b and HAT-P-23b and report on the performance of the observatory. The OSO consists of two 0.4 meter class telescopes (PIRATE and COAST) used for undergraduate distance learning and research (Kolb et al 2018). The telescopes, located at Teide Observatory on Tenerife at an altitude of 2390m, can be operated remotely in real time for teaching or fully autonomously via an automated scheduler. Teide Observatory provides an excellent location with typical seeing of 0.6” and an average 280 clear nights per year. Our new observations, supplemented with additional data from a telescope located in the UK and previously published results, show that HAT-P-23b is slightly less inflated than previously reported and not eccentric. We find that a linear ephemeris is the best fit to the available timing data. For WASP-52b we slightly prefer a quadratic ephemeris indicative of period change. Further observations through the 2020-21 observing season should discriminate between the linear and quadratic ephemerides

Parameters of two low-mass contact eclipsing binaries near the short-period limit

The two objects 1SWASP J150822.80-054236.9 and 1SWASP J160156.04+202821.6 were initially detected from their SuperWASP archived light curves as candidate eclipsing binaries with periods close to the short-period cut-off of the orbital period distribution of main-sequence binaries, at ~0.2 d. Using spectroscopic data from the Isaac Newton Telescope in La Palma, Canary Islands, we here confirm them as double-lined spectroscopic and eclipsing binaries, in contact configuration. Following modelling of their visual light curves and radial velocity curves, we determine their component and system parameters to precisions between ~2 and 11%. The first system contains components of 1.07 and 0.55 M⊙, with radii of 0.90 and 0.68 R⊙, respectively; its primary exhibits pulsations with a period of 1/6 of the orbital period of the system. The latter contains components of 0.86 and 0.57 M⊙, with radii of 0.75 and 0.63 R⊙, respectively

A definição dos idosos de qualidade de vida

OBJECTIVES: Senescence for some elderly people is a phase of with development and satisfaction, whereas for others is a negative stage of life. The determinants of a good quality of life in old age vary from person to person. The aims of this study were to identify: 1) the prevalence of octogenarian people who evaluate their current life as being mainly characterized by a positive quality and 2) which were the domains that they identified as being the determinants of this positive quality. A same parallel study was conducted with subjects who evaluated senescence as a preponderantly negative experience. METHODS: A random and representative sample of 35% of the octogenarian people, living residing in the community, was selected among the dwellers of the city of Veranópolis, state of Rio Grande do Sul. A semi-structured questionnaire on quality of life quality was applied as well as the scale of depressive symptoms Geriatric Depression Scale (GDS) and the index of general health Cumulative Illness Rating Scale (CIRS). RESULTS: Slightly more than half of the studied sample (57%) defined their current quality of life with positive evaluations, whereas 18% presented a negative evaluation of it. A group 0f 25% defined their current lives as neutral or having both values (positive and negative). Those who were dissatisfied presented more health problems according to the CIRS and more depressive symptoms when evaluated by the GDS. Satisfied subjects ones had different reasons to justify this state, however, the dissatisfied had mainly the lack of health as a reason for their suffering. The main source of reported daily well-being was the involvement with rural or domestic activities. Among the interviewed, lack of health was the main source for not presenting well-being, although there was interpersonal variability regarding what each subject considered as loss of health. CONCLUSION: Possibly, for the elderly subjects a negative quality of life is equivalent to loss of health and a positive life quality is equivalent to a greater range of categories such as activity, income, social life and relationship with the family, categories which differed from subject to subject. Therefore, health seems to be a good indicator of negative quality of life, though an insufficient indicator of successful elderliness.OBJETIVOS: A velhice para alguns é uma etapa de desenvolvimento e satisfação, enquanto para outros é uma fase negativa da vida. Os determinantes da boa qualidade de vida na velhice variam de sujeito para sujeito. O objetivo do presente estudo foi identificar: 1) a prevalência de octagenários que avaliavam sua vida atual na velhice como preponderantemente de uma qualidade positiva e 2) quais aspectos eles identificavam como os determinantes desta qualidade positiva. Igual estudo em paralelo foi feito com sujeitos que avaliavam a velhice como uma experiência preponderantemente negativa. MÉTODOS: Uma amostra randômica e representativa de 35% dos idosos com mais de 80 anos residentes na comunidade foi selecionada entre os residentes em Veranópolis, Rio Grande do Sul. Um questionário semi- estruturado de qualidade de vida foi aplicado, bem como a escala de sintomas depressivos Geriatric Depression Scale (GDS) e o Índice de Saúde Geral Cumulative Illness Rating Scale (CIRS). RESULTADO: Um pouco mais da metade dos idosos estudados (57%) definia sua qualidade de vida atual com avaliações positivas, sendo que 18% tinham uma avaliação negativa da vida atual. Um grupo de 25% definia sua vida atual de forma neutra ou de dois valores (aspectos positivos e aspectos negativos). Comparados com os satisfeitos, os insatisfeitos tinham mais problemas de saúde pela CIRS e mais sintomas depressivos quando avaliados pela GDS. Os satisfeitos tinham diferentes motivos para justificar este estado, porém os insatisfeitos tinham principalmente a falta de saúde física como motivo do sofrimento. A maior fonte de bem estar no dia-a-dia citada era o envolvimento com atividades rurais ou domésticas. Entre os entrevistados, a perda da saúde física era a principal fonte de mal estar, sendo que havia variabilidade interpessoal quanto ao que cada sujeito considerava como perda de saúde. CONCLUSÃO: É possível que para idosos, qualidade negativa de vida seja equivalente a perda de saúde e qualidade de vida positiva seja equivalente a uma pluralidade maior de categorias como atividade, renda, vida social e relação com a família, categorias diferentes de sujeito para sujeito. O aspecto saúde parece assim um bom indicador de qualidade de vida negativa, porém um indicador insuficiente de velhice bem sucedida.Catholic University of the state of Rio Grande do Sul Institute of Geriatrics and Gerontology Geriatric neuropsychiatric ambulatoryWHO PAHO Associated Chronic Degenerating DiseasesFederal University of São Paulo Paulista Medical School Department of PsychiatryPUCRS Medical School Department of PsychiatryUNIFESP, EPM, Department of PsychiatrySciEL

The SuperWASP catalogue of 4963 RR Lyr stars: identification of 983 Blazhko candidates

Aims. We set out to compile a catalogue of RRab pulsating variables in the SuperWASP archive and identify candidate Blazhko effect objects within this catalogue. We analysed their light curves and power spectra for correlations in their common characteristics to further our understanding of the phenomenon. Methods. Pulsation periods were found for each SWASP RRab object using PDM techniques. Low frequency periodic signals detected in the CLEAN power spectra of RRab stars were matched with modulation sidebands and combined with pairs of sidebands to produce a list of candidate Blazhko periods. A novel technique was used in an attempt to identify Blazhko effect stars by comparing scatter at different parts of the folded light curve. Pulsation amplitudes were calculated based on phase folded light curves.Results. The SuperWASP RRab catalogue consists of 4963 objects of which 3397 are previously unknown. We discovered 983 distinct candidates for Blazhko effect objects, 613 of these being previously unknown in the literature as RR Lyrae stars, and 894 are previously unknown to be Blazhko effect stars. Correlations were investigated between the scatter of points on the light curve, the periods and amplitudes of the objects’ pulsations, and those of the Blazhko effect.Conclusions. A statistical analysis has been performed on a large population of Blazhko effect stars from the wide-field SuperWASP survey. No correlations were found between the Blazhko period and other parameters including the Blazhko amplitude, although we confirmed a lower rate of occurrence of the Blazhko effect in long pulsation period objects

Monorail/Foxa2 regulates floorplate differentiation and specification of oligodendrocytes, serotonergic raphe neurones and cranial motoneurones

In this study, we elucidate the roles of the winged-helix transcription factor Foxa2 in ventral CNS development in zebrafish. Through cloning of monorail (mol), which we find encodes the transcription factor Foxa2, and phenotypic analysis of mol(-/-) embryos, we show that floorplate is induced in the absence of Foxa2 function but fails to further differentiate. In mol(-/-) mutants, expression of Foxa and Hh family genes is not maintained in floorplate cells and lateral expansion of the floorplate fails to occur. Our results suggest that this is due to defects both in the regulation of Hh activity in medial floorplate cells as well as cell-autonomous requirements for Foxa2 in the prospective laterally positioned floorplate cells themselves. Foxa2 is also required for induction and/or patterning of several distinct cell types in the ventral CNS. Serotonergic neurones of the raphe nucleus and the trochlear motor nucleus are absent in mol(-/-) embryos, and oculomotor and facial motoneurones ectopically occupy ventral CNS midline positions in the midbrain and hindbrain. There is also a severe reduction of prospective oligodendrocytes in the midbrain and hindbrain. Finally, in the absence of Foxa2, at least two likely Hh pathway target genes are ectopically expressed in more dorsal regions of the midbrain and hindbrain ventricular neuroepithelium, raising the possibility that Foxa2 activity may normally be required to limit the range of action of secreted Hh proteins

Nonlocal Effects and Shrinkage of the Vortex Core Radius in YNi2B2C Probed by muSR

The magnetic field distribution in the vortex state of YNi2B2C has been probed by muon spin rotation (muSR). The analysis based on the London model with nonlocal corrections shows that the vortex lattice has changed from hexagonal to square with increasing magnetic field H. At low fields the vortex core radius, rho_v(H), decreases with increasing H much steeper than what is expected from the sqrt(H) behavior of the Sommerfeld constant gamma(H), strongly suggesting that the anomaly in gamma(H) primarily arises from the quasiparticle excitations outside the vortex cores.Comment: 4 pages, 4 figures, submitted to Phys. Rev.

Does Quantum Mechanics Clash with the Equivalence Principle - and Does it Matter?

With an eye on developing a quantum theory of gravity, many physicists have recently searched for quantum challenges to the equivalence principle of general relativity. However, as historians and philosophers of science are well aware, the principle of equivalence is not so clear. When clarified, we think quantum tests of the equivalence principle won't yield much. The problem is that the clash/not-clash is either already evident or guaranteed not to exist. Nonetheless, this work does help teach us what it means for a theory to be geometric.Comment: 12 page

On the nature of the X-ray source in GK Per

We report XMM-Newton observations of the intermediate polar (IP) GK Per on the rise to the 2002 outburst and compare them to Chandra observations during quiescence. We find an asymmetric spin light curve implying an asymmetric shape of a semi-transparent accretion curtain. A low Fe xvii (15.01/15.26 A) line flux ratio confirms the need for an asymmetric geometry and significant effects of resonant line scattering. Medium resolution spectra in outburst and quiescence are both fitted with a leaky absorber model for the post shock hard X-ray emission, a black body (outburst) for the thermalized X-ray emission from the white dwarf and an optically thin spectrum. The difference between high and low spin as well as QPO/flares states can be explained by a variation in the absorbing column density. The Fe fluorescence at 6.4 keV (equivalent width of 447 eV) is not significantly variable during spin cycle or on QPO periods. High-resolution RGS spectra reveal a number of emission lines from H-like and He-like elements. The lines are broader than the instrumental response with a roughly constant velocity dispersion for different lines, indicating identical origin. He-like emission lines are used to give values for the electron densities of log n_e ~ 12. We do not detect any variation in the emission lines during the spin cycle, implying that the lines are not noticeably obscured or absorbed. We conclude that they originate in the accretion curtains and propose a model for their shape.Comment: 14 pages, 22 figures, accepted by A&A; text re quiescent data changed slightly, references adde