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

Growth performance, cleanliness and lameness of finishing Charolais bulls housed in littered pens of different design

The fattening of beef cattle in Italy is mainly carried out under intensive rearing conditions. The main features of the Italian beef farms are the high stocking rate and the loose housing of the animals in multiple pens indoors. The pen with fully slatted floor is the most frequent housing solution because it does not require any bedding material and it has a lower labour cost to remove slurry

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

Crown condition assessment at the CONECOFOR Permanent Monitoring Plots.

A detailed crown condition assessment is currently being carried out at the CONECOFOR (CONtrollo ECOsistemi FORestali, Control of Forest Ecosystems) plots. The assessment began in 1996, and during the first two years (1996 and 1997) an assessment form based on previous regional experience was used; in 1998 the new official EU form was adopted. The resulting loss of comparability means that only a few indices can be used in the temporal series 1996-1999. Much effort was devoted to Quality Assurance (QA) procedures. The QA program is structured as follows: (i) specific field manuals have been adopted and are continuously updated; (ii) a national training and intercalibration course (NT&IC) is undertaken yearly before beginning the assessment campaign;( iii) field checks are carried out yearly on a large number of plots. The results of the QA program have shown that for several indices the quality objectives were not reached, but the quality of the data is improving with time. To express the change in crown conditions in each area, a complex index (CCI = Crown Condition Index) was adopted. This index is the result of the sum of the relativized values of all the common indices used during the four years. The following parameters were used: transparency, ramification type, leaf colour alteration extension, leaf damage extension, alteration of leaf distension extension. The range within which the CCI fluctuates was evaluated taking into account all the observations carried out at a given plot throughout the years. The number of cases over a given threshold (outliers) was calculated for each year. The threshold for outliers was calculated as the median value plus 2 times the range of the interquartile value. All individual cases exceeding this value are considered outliers. The results are presented for all the areas in which the data set is complete for the four years. The yearly fluctuations are discussed and related to possible causes

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