Three dimensionality in the wake of the flow around a circular cylinder at Reynolds number 5000

The turbulent flow around a circular cylinder has been investigated at Re=5000Re=5000 using direct numerical simulations. Low frequency behavior, vortex undulation, vortex splitting, vortex dislocations and three dimensional flow within the wake were found to happen at this flow regime. In order to successfully capture the wake three dimensionality, different span-wise lengths were considered. It was found that a length LZ=2pDLZ=2pD was enough to capture this behavior, correctly predicting different aspects of the flow such as drag coefficient, Strouhal number and pressure and velocity distributions when compared to experimental values. Two instability mechanisms were found to coexist in the present case study: a global type instability originating in the shear layer, which shows a characteristic frequency, and a convective type instability that seems to be constantly present in the near wake. Characteristics of both types of instabilities are identified and discussed in detail. As suggested by Norberg, a resonance-type effect takes place in the vortex formation region, as the coexistence of both instability mechanisms result in distorted vortex tubes. However, vortex coherence is never lost within the wake.Peer ReviewedPostprint (author's final draft

Optical Spectroscopy of X-Mega targets in the Carina Nebula - VI. FO 15: a new O-Type double-lined eclipsing binary

We report the discovery of a new O-type double-lined spectroscopic binary with a short orbital period of 1.4 days. We find the primary component of this binary, FO 15, to have an approximate spectral type O5.5Vz, i.e. a Zero-Age-Main-Sequence star. The secondary appears to be of spectral type O9.5V. We have performed a numerical model fit to the public ASAS photometry, which shows that FO 15 is also an eclipsing binary. We find an orbital inclination of ~ 80 deg. From a simultaneous light-curve and radial velocity solution we find the masses and radii of the two components to be 30 +/- 1 and 16 +/- 1 solar masses and 7.5 +/- 0.5 and 5.3 +/- 0.5 solar radii. These radii, and hence also the luminosities, are smaller than those of normal O-type stars, but similar to recently born ZAMS O-type stars. The absolute magnitudes derived from our analysis locate FO 15 at the same distance as Eta Carinae. From Chandra and XMM X-ray images we also find that there are two close X-ray sources, one coincident with FO 15 and another one without optical counterpart. This latter seems to be a highly variable source, presumably due to a pre-main-sequence stellar neighbour of FO 15.Comment: 11 pages, 9 figures, 3 tables. Accepted for publication in MNRAS. Higher resolution version available at http://lilen.fcaglp.unlp.edu.ar/papers2006.htm

Redefining the performing arts archive

This paper investigates representations of performance and the role of the archive. Notions of record and archive are critically investigated, raising questions about applying traditional archival definitions to the performing arts. Defining the nature of performances is at the root of all difficulties regarding their representation. Performances are live events, so for many people the idea of recording them for posterity is inappropriate. The challenge of creating and curating representations of an ephemeral art form are explored and performance-specific concepts of record and archive are posited. An open model of archives, encouraging multiple representations and allowing for creative reuse and reinterpretation to keep the spirit of the performance alive, is envisaged as the future of the performing arts archive

Cuban creole pig in Bayamo jurisdiction

The former jurisdiction of Bayamo, as political colonial division began its way in the century XVI, after its foundation in 1513 as the second Cuban village. Currently the Bayamo village is integrated by 15 local districts, an extension of 835.12 km2 and a population 68690 inhabitants. In spite of have elapsed more than 470 years from the arrival of the first pigs from Spain, this region has maintained 6176 breeders of this native pig breed as direct descendant of the Mediterranean pigs. In this work is presented the racial, ecological and human factors, that they have permitted the maintenance of this population with origin in the Iberian pig.La antigua jurisdicción de Bayamo, como división política de la colonia comenzó su andadura en el siglo XVI, tras su fundación en 1513 como la segunda villa de Cuba. Actualmente el municipio de Bayamo lo integran 15 consejos populares, una superficie de 835,12 km2 y una población de 68690 habitantes. A pesar de haber transcurrido más de 470 años desde la llegada de los primeros cerdos desde España, esta región ha mantenido 6176 reproductores de la raza cerdo Criollo como descendiente directo de los cerdos mediterráneos. En este trabajo se presenta los factores racial, ecológico y humano, que han permitido la perdurabilidad de esta raza descendiente del cerdo Ibérico

The Black Creole Cuban Pig: origin, evolution and present status

The origin of the Cuban Creole Black pig is under a controversy, but the majority of authors locate their procedure in the ancient Spanish Iberian branches. Others hypothesis point out a possible influence of pre-hispanic Black Canarian pig, and also the early influence of Duroc and Hampshire breeds. Coinciding with all the Cuban farming development, this breed increase greatly their census from the beginning of the colonisation to the first half of the XVIIIth century, when their decreasing started as a consequence of the big expansion of tobacco and sugar Cain agriculture. In the present century this breed was in risk of extinction because the competence of improved foreign breeds, but presently this bred has gain god perspectives, because her role in the Cuban sustainable development.El origen del Cerdo Negro Criollo Cubano sigue siendo discutido, aunque la mayoría de los autores atribuyen su procedencia de los antiguos troncos ibéricos de España. Otras hipótesis plantean una posible influencia de los cerdos canarios prehispánicos e incluso el aporte reciente de sangre de las razas Duroc y Hampshire. Esta raza, coincidiendo con todo el desarrollo ganadero cubano, incrementó enormemente sus censos desde el inicio de la colonización hasta la primera mitad del siglo XVIII donde comenzó su declive a consecuencia de la gran expansión de la explotación tabacalera y de la caña de azúcar. En el presente siglo ha peligrado su conservación por la competencia de las razas selectas extranjeras aunque en la actualidad presenta unas excelentes perspectivas de recuperación dentro del desarrollo sostenible de Cuba

Extern characterisation of iberian pig varieties based in cualitative variables

We are presenting a study of the external charcaterization of nine varieties of the Iberian pig based on seven cualitative external characteritics. We have used a sample of 566 adult individuals (515 females and 51 males) belonging to 28 different farm of the Iberian Pig Breed. The results of the non parametric ANOVA, the canonical discriminant analysis and Mahalanobis distancing have confirmed a clear differentiation among varieties, resulting the Torbiscal and Manchado de Jabugo varieties as the most distanced.Se realiza un estudio de caracterización exteriorista de las distintas variedades del cerdo Ibérico utilizando una muestra formada por un total de 566 individuos (515 hembras y 51 machos) pertenecientes a nueve variedades de la raza Ibérica. Para ello se analizan un total de siete variables cualitativas. Tanto los resultados del análisis de la varianza no paramétrico, el análisis discriminante canónico, como las distancias de Mahanalobis, nos confirman una clara diferenciación de todas las variedades de la raza basada en dichas variables, quedando el Torbiscal y el Manchado de Jabugo como las variedades más destacadas