Phase-averaged characterization of turbulent isothermal free swirling jet after vortex breakdown

This work mainly focused on the near-exit region of a round isothermal free swirling jet to characterize the effect of swirl on the flow field and to identify large coherent structures. 3C-2D PIV was employed to capture the instantaneous flow field close to the nozzle exit for non-swirling (S=0) and a high swirling jets (S=1.26) both with a Reynolds number of 21800. At swirl level of 1.26 the pressure fluctuations measured by a capacitive microphone indicate the existence of periodic instability, the so called precessing vortex core (PVC). A three-component proper orthogonal decomposition (POD) applied to the instantaneous velocity fields allow to identify the dominant flow structure associated to the PVC. The time coefficients of the two first most energetic POD modes were used to reconstruct the phase of the oscillatory motion in the swirling flow. The phase information was then used to conditionally average the instantaneous velocity field s, this allowed the 3D structure of the PVC to be reconstructed. The instantaneous minima of negative swirling strength values calculated from the instantaneous velocity field revealed the presence of two helical structures located in the inner and outer shear layers. By phase averaging the instantaneous swirling strength maps, the 3D helical vortex structure was reconstructed . The two co-winding counter-rotating helical structure fade out at an axial location of approximately z/ D = 1.5. The findings evidence that the combined application of PIV, POD and frequency analysis using capacitive microphone can provide detailed observations of coherent fluctuations ind uced by vortex precession

AN EXPERIMENTAL INVESTIGATION ON ISOTHERMAL FREE SWIRLING JET

This paper reports an experimental investigation on the dynamics of turbulent unconfined swirling flows. Isothermal free swirling jets with five different swirl numbers (S) and fixed Reynolds number (Re = 21800) are investigated to analyze the effect of swirl intensity on the recirculation, vortex breakdown and the occurrence of the precession vortex core (PVC) by means of 3C-2D Stereoscopic Particle image velocimetry (PIV). The contours and radial profiles of mean axial velocity confirmed the central recirculation zone (CRZ) for high swirl number. The importance of central recirculation zone is to ensure a good mixing of air/ fuel and combustion products and to generate a low velocity region for flame stabilization. Results shows that swirl intensity increases the backflow rate in the recirculation zone and jet spreads almost linearly with a higher spread rate as compared to non swirling flow. The frequency characteristics have been measured with a capacitive microphone. The frequency spectrum indicates the presence of periodic oscillation related to the existence of PVC. The Strouhal number associated with the frequency of the PVC vary almost linearly with swirl intensity

Multi-aspect testing and ranking inference to quantify dimorphism in the cytoarchitecture of cerebellum of male, female and intersex individuals: a model applied to bovine brains.

The dimorphism among male, female and freemartin intersex bovines, focusing on the vermal lobules VIII and IX, was analyzed using a novel data analytics approach to quantify morphometric differences in the cytoarchitecture of digitalized sections of the cerebellum. This methodology consists of multivariate and multi-aspect testing for cytoarchitecture-ranking, based on neuronal cell complexity among populations defined by factors, such as sex, age or pathology. In this context, we computed a set of shape descriptors of the neural cell morphology, categorized them into three domains named size, regularity and density, respectively. The output and results of our methodology are multivariate in nature, allowing an in-depth analysis of the cytoarchitectonic organization and morphology of cells. Interestingly, the Purkinje neurons and the underlying granule cells revealed the same morphological pattern: female possessed larger, denser and more irregular neurons than males. In the Freemartin, Purkinje neurons showed an intermediate setting between males and females, while the granule cells were the largest, most regular and dense. This methodology could be a powerful instrument to carry out morphometric analysis providing robust bases for objective tissue screening, especially in the field of neurodegenerative pathologies

Posttransplant lymphoproliferative disorders in neuronal xenotransplanted macaques

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations that occur in the setting of depressed T-cell function due to immunosuppressive therapy used following solid organ transplantation, hematopoietic stem cell transplantation, and also xenotransplantation. In the present study, 28 immunosuppressed parkinsonian Macaca fascicularis were intracerebrally injected with wild-type or CTLA4-Ig transgenic porcine xenografts to identify a suitable strategy to enable long-term cell survival, maturation, and differentiation. Nine of 28 (32%) immunosuppressed primates developed masses compatible with PTLD, located mainly in the gastrointestinal tract and/or nasal cavity. The masses were classified as monomorphic PTLD according to the World Health Organization classification. Immunohistochemistry and polymerase chain reaction (PCR) analyses revealed that the PTLDs were associated with macaca lymphocryptovirus as confirmed by double-labeling immunohistochemistry for CD20 and Epstein-Barr nuclear antigen 2 (EBNA-2), where the viral protein was located within the CD20+ neoplastic B cells. In sera from 3 distinct phases of the experimental life of the primates, testing by quantitative PCR revealed a progression of the viral load that paralleled the PTLD progression and no evidence of zoonotic transmission of porcine lymphotropic herpesvirus through xenoneuronal grafts. These data suggest that monitoring the variation of macaca lymphocryptovirus DNA in primates could be used as a possible early diagnostic tool for PTLD progression, allowing preemptive treatment such as immunosuppression therapy reduction

Nomenclature for the C60-Ih and C70-D5h(6) fullerenes (IUPAC Recommendations 2002)

Fullerenes are a new allotrope of carbon characterized by a closed-cage structure consisting of an even number of three-coordinate carbon atoms devoid of hydrogen atoms. This class was originally limited to closed-cage structures with 12 isolated five-membered rings, the rest being six-membered rings. Although it was recognized that existing organic ring nomenclature could be used for these structures, the resulting names would be extremely unwieldy and inconvenient for use. At the same time it was also recognized that established organic nomenclature principles could be used, or adapted, to provide a consistent nomenclature for this unique class of compounds based on the class name fullerene. However, it was necessary to develop an entirely new method for uniquely numbering closed-cage systems. This paper describes IUPAC recommendations for naming and uniquely numbering the two most common fullerenes with isolated pentagons, the icosahedral C60 fullerene and a D5h-C70 fullerene. It also describes recommendations for adapting organic nomenclature principles for naming fullerenes with nonclosed-cage structures, heterofullerenes, derivatives formed by substitution of hydrofullerenes, and the fusion of organic rings or ring systems to the fullerene cage. Finally, this paper suggests methods for describing structures consisting of two or more fullerene units and for denoting configurations of chiral fullerenes and their derivative

Synthetic rubber surface as an alternative to concrete to improve welfare and performance of finishing beef cattle reared on fully slatted flooring

open8noopenBrscic, M.; Ricci, R.; Prevedello, P.; Lonardi, C.; De Nardi, R.; Contiero, B.; Gottardo, F.; Cozzi, G.Brscic, Marta; Ricci, Rebecca; Prevedello, P.; Lonardi, Chiara; DE NARDI, Roberta; Contiero, Barbara; Gottardo, Flaviana; Cozzi, Giuli