An experimental study of wall-injected flows in a rectangular cylinder

An experimental investigation of the flow inside a rectangular cylinder with air injected continuously along the wall is performed. This kind of flow is a two-dimensional approximation of what happens inside a solid rocket motor, where the lateral grain burns expelling exhaust gas or in processes with air filtration or devices to attain uniform flows. We propose a brief derivation of some analytical solutions and a comparison between these solutions and experimental data, which are obtained using the Particle Image Velocimetry (PIV) technique, in order to provide a global reconstruction of the flowfield. The flow, which enters orthogonal to the injecting wall, turns suddenly its direction being pushed towards the exit of the chamber. Under the incompressible and inviscid flow hypothesis, two analytical solutions are reported and compared. The first one, known as Hart-McClure solution, is irrotational and the injection velocity is non-perpendicular to the injecting wall. The other one, due to Taylor and Culick, has non-zero vorticity and constant, vertical injection velocity. The comparison with laminar solutions is useful to assess whether transition to turbulence is reached and how the disturbance thrown in by the porous injection influences and modifies those solutions

Payloads development for European land mobile satellites: A technical and economical assessment

The European Space Agency (ESA) has defined two payloads for Mobile Communication; one payload is for pre-operational use, the European Land Mobile System (EMS), and one payload is for promoting the development of technologies for future mobile communication systems, the L-band Land Mobile Payload (LLM). A summary of the two payloads and a description of their capabilities is provided. Additionally, an economic assessment of the potential mobile communication market in Europe is provided

Celtis ehrenbergiana (Celtidaceae): meristematic tissue in the thorns [Celtis ehrenbergiana (Celtidaceae): tejido meristemático en las espinas]

El tala (Celtis ehrenbergiana) es un árbol con espinas que posee propiedades medicinales, brinda alimento y refugio a otras especies y protege elambiente. Se realizó el estudio anatómico de las espinas de tala a fin de establecer la presencia de tejido meristemático (yemas). Las muestras de espinasfueron procesadas empleando técnicas estándares para microscopía óptica. Solamente una de las dos espinas geminadas localizadas en la proximidad del ápicede ramas en activo crecimiento presenta dos yemas: una apical y otra lateral en posición sub-apical. Sería interesante ensayar estas porciones con célulasmeristemáticas en activa división con técnicas de micropropagación in vitro

Anatomía de los cladodios de Opuntia (Cactaceae) de la provincia de Buenos Aires, Argentina

The aim of this study was to deepen the knowledge of the cladodes anatomy of nine species of Opuntia that grow in the province of Buenos Aires, Argentina. Fresh and herbarium samples were prepared according to usual methods for light microscope. Histochemical techniques were performed to identify starch, mucilage and oxalate salts. The main traits found were: epidermis smooth and uniseriate, covered by a thin cuticle and epicuticular waxes; large (range 36-57 µm length) stomata in low density (range 21-27/ mm2), located at level respect to the rest of epidermal cells with a deep substomatal chamber; a multiseriate hypodermis with one crystal layer; the cortex with external chlorenchyma and internal hydrenchyma. The eustele presents different size of vascular bundles; in some species the large ones have a secretory duct adjacent to the phloem. Some species showed wide-band tracheids and a few presented fibres in their vascular bundles. Some characters (presence of fibres and ducts) may be a useful tool for plant identification. However, many open questions remain to be investigated such as the correlation of the environment factors with hypodermis, calcium oxalate crystals, and wide-band tracheids.Anatomía de los cladodios de Opuntia (Cactaceae) de la provincia de Buenos Aires, Argentina. El objetivo de este trabajo fue profundizar el conocimiento de la anatomía de los cladodios de nueve especies de Opuntia que crecen en la provincia de Buenos Aires, Argentina. Se hicieron preparaciones con material fresco y ejemplares de herbario siguiendo métodos habituales para microscopía óptica. Se usaron técnicas histoquímicas para identificar almidón, mucílagos y sales de oxalato. Las principales características halladas fueron: epidermis lisa y uniseriada, cutícula delgada y ceras epicuticulares; estomas grandes (entre 36-57 µm long) en baja densidad (entre 21-27/ mm2), ubicados a nivel con respecto a las restantes células epidérmicas y con una profunda cámara subestomática; hipodermis multiseriada con capa cristalífera; la corteza con clorénquima externo e hidrénquima interno. La eustela presenta haces vasculares de diferente tamaño, en algunas especies los haces mayores presentan un conducto secretor adyacente al floema. Algunas especies presentaron traqueidas con bandas de engrosamiento secundario y muy pocas tuvieron fibras en sus haces vasculares. La presencia de fibras y conducto adyacente al floema pueden ser caracteres útiles en la identificación de especies. Sin embargo, muchos aspectos requieren mayor investigación en relación con los factores ambientales, tales como la hipodermis, los cristales de oxalato de calcio y las traqueidas con bandas de engrosamiento secundario.

Astrophysical and Cosmological Information from Large-scale sub-mm Surveys of Extragalactic Sources

We present a quantitative analysis of the astrophysical and cosmological information that can be extracted from the many important wide-area, shallow surveys that will be carried out in the next few years. Our calculations combine the predictions of the physical model by Granato et al. (2004) for the formation and evolution of spheroidal galaxies with up-to-date phenomenological models for the evolution of starburst and normal late-type galaxies and of radio sources. We compute the expected number counts and the redshift distributions of these source populations separately and then focus on proto-spheroidal galaxies. For the latter objects we predict the counts and redshift distributions of strongly lensed sources at 250, 350, 500, and 850 micron, the angular correlation function of sources detected in the surveys considered, the angular power spectra due to clustering of sources below the detection limit in Herschel and Planck surveys. An optimal survey for selecting strongly lensed proto-spheroidal galaxies is described, and it is shown how they can be easily distinguished from the other source populations. We also discuss the detectability of the imprints of the 1-halo and 2-halo regimes on angular correlation functions and clustering power spectra, as well as the constraints on cosmological parameters that can be obtained from the determinations of these quantities. The novel data relevant to derive the first sub-millimeter estimates of the local luminosity functions of starburst and late-type galaxies, and the constraints on the properties of rare source populations, such as blazars, are also briefly described.Comment: 16 pages, 10 figures. Accepted for publication on MNRA

Heavy particles in the near field of a turbulent jet

The behaviour of aluminium spherical particles of density ρp=2700 Kg/m3 dispersed in a turbulent round water jet, at Reynolds number Re≈15000 and exit Stokes number St0=0.013 is investigated via Particle Image Velocimetry up to x/D=16 from the nozzle exit. Average and fluctuating velocity fields are analysed and compared to the unladen jet condition. Generally, particles are reported not to behave like tracers, in particular outside the region of the jet potential core. Velocity fluctuations are reported to differ from the fluid fluctuations in particular at the jet centreline and shear layers. In particular, axial velocity fluctuations appear to be dominated by the fluid phase whereas a tendency towards an increase of radial fluctuations downstream of the jet exit is reported for particles. The complexity of this scenario suggests a selective particle response with respect to the flow dynamics

Numerical study of halo concentrations in dark-energy cosmologies

We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and compare them with "standard'' Lambda-CDM and OCDM models. We find that previously proposed algorithms for predicting halo concentrations can be well adapted to dark-energy models. When centred on the analytically expected values, halo concentrations show a log-normal distribution with a uniform standard deviation of ~0.2. The dependence of averaged halo concentrations on mass and redshift permits a simple fit of the form (1+z) c=c0 (M/M0)^a, with a~-0.1 throughout. We find that the cluster concentration depends on the dark energy equation of state at the cluster formation redshift z_{coll} through the linear growth factor D_+(z_{coll}). As a simple correction accounting for dark-energy cosmologies, we propose scaling c0 from Lambda-CDM with the ratio of linear growth factors, c0 -> c0 D_+(z_{coll})/D_{+,Lambda-CDM}(z_{coll}).Comment: 11 pages, submitted to Astronomy & Astrophysic

The Ventasso Horse: genetic characterization by microsatellites markers

The genetic structure of Ventasso Horse (VH) was investigated using 12 microsatellites. The analyses were carried out on 117 VH individuals and the results were compared with those obtained analysing 11 other breeds reared in Italy. All microsatellites were polymorphic in VH and in the other breeds. A total of 124 alleles (from 6 to 19 alleles per microsatellite) were detected. Average heterozygosity was 0.743 in VH and ranged from 0.613 to 0.759 in the other breeds. The mean FST value had an average value of 0.0932. Genetic distances were calculated using Nei's standard genetic distance (Ds). The smallest Ds values were found between VH and Anglo-Arab, Thoroughbred, Maremmano and Lipizzan horse breeds. Phylogenetic trees constructed using neighbour-joining method showed two clear separate clusters: the first includes Bardigiano, Haflinger and Italian Heavy Draught Horse, the second contains the other 9 breeds

Sentinel node biopsy and radical lymph node dissection for advanced melanoma in the elderly

Articolo presente su PubMed Central. Sourcerecord Id Scopus: 28558 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3194399/ Background.The majority of indications for surgery in melanoma are for the treatment of primary tumor and lymph node metastases. During the last decade, the Sentinel Node Biopsy (SNB), from a research procedure, has become standard of care in most institutions. SNB is normally considered for patients with melanoma > 1 mm and generally about 20% are positive; however, the risk of a positive SNB in a melanoma < 1 mm is still 5%. Usually when SNB is positive a complete lymphadenectomy is performed. Materials and methods.In the period 2004-2009, 18 elderly patients (median age 68 years) affected by cutaneous melanoma (mean Breslow’s thickness = 3.77 mm), after SNB histologically confirmed regional lymph node involvement, underwent complete lymph node dissection (CLND). We treated 11 of them with groin dissection, in 3 cases bilateral; 4 patients underwent axillar dissection, in one case bilateral; 2 patients underwent neck dissection and another patient underwent groin-axillar dissection. We treated bilateral groin involvement with laparoscopic access for dissection of lumbar-aortic, iliac and obturator lymph nodes. Results.Disagreeing with literature, 12/18 (67%) of these patients had positive lymph nodes, a high percentage if compared with younger patients’ data. Currently the average follow-up is 25 months. In our sample CLND has a crucial prognostic role (16% vs 41% of deceased in CLND – and CLND + patients respectively). Conclusions.Elderly melanoma patients are characterized by a higher tumor stage and, in patients with nodal metastases, the prognosis is independently affected by older age. In case of positive SNB the CLND plays a notable prognostic role and a presumable therapeutic role