365 research outputs found

    Visualization Of Supersonic Flows In Shock Tunnels, Using The Background Oriented Schlieren Technique

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    Visualisation of supersonic compressible flows using the Background Oriented Schlieren (BOS) technique is presented. Results from experiments carried out in a reflected shock tunnel with models of a 20-degree semi-vertex angle circular cone and a re-entry body in the test section are presented. This technique uses a simple optical set-up consisting of a structured background pattern, an electronic camera with a high shutter speed and a high intensity light source. Tests were conducted with a Mach 4 conical nozzle, with nozzle supply pressure of 2 MPa and nozzle supply temperature of 2000 K respectively. The images captured during the test were compared using PIV style image processing code. The intensity of light at each point in the processed image was proportional to the density at that point. Qualitative visualization of shock shapes, with images clearly indicating regions of subsonic and supersonic flows was achieved. For the cone, the shock angle measured from the BOS image agreed with theoretical calculations to within 0.5 degrees. Shock standoff distances could be measured from the BOS image for the re-entry body

    Elevation of conjunctival epithelial CD45INTCD11b⁺CD16⁺CD14⁻ neutrophils in ocular Stevens-Johnson syndrome and toxic epidermal necrolysis

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    PURPOSE. Ocular complications related to Stevens-Johnson Syndrome (SJS)–Toxic Epidermal Necrolysis (TEN) may persist and progress after resolution of systemic disease. This is thought to be related in part to persistent ocular innate-immune signaling. In this study, our aim was to characterize infiltrative conjunctival cellular profiles during acute (<12 months) and chronic (>12 months) disease. METHODS. Consecutive patients presenting with SJS-TEN over a 12-month period were followed for 1 year. Detailed clinical examination and conjunctival impression cell recovery was analyzed by flow cytometry for the presence of intraepithelial leukocytes and compared with healthy controls (n = 21). RESULTS. Ten patients were recruited of whom six had acute disease and five were classified as TEN (SCORTEN = 1, n = 4). Conjunctival inflammation was graded as absent/mild in a total of nine patients; but despite this, evidence of fornix shrinkage was observed in nine subjects. This inversely correlated with disease duration (P < 0.05). A reduction in percentage of CD8αβ(+) T cells compared with controls (80% vs. 57%; P < 0.01) was associated with a corresponding increase in the number/percentage of CD45(INT)CD11b(+)CD16(+)CD14(−) neutrophils (186 vs. 3.4, P < 0.01, 31% vs. 0.8%, P < 0.001). Neutrophils inversely correlated with disease duration (r = −0.71, P = 0.03), yet there was no absolute change in the CD8αβ(+) or neutrophil populations during the study period (P = 1.0). CONCLUSIONS. These data highlight that a neutrophilic infiltrate is present in mildly inflamed or clinically quiescent conjunctival mucosa in patients with ocular SJS-TEN, where neutrophil numbers inversely correlate with disease duration. Neutrophil persistence endorses the hypothesis of an unresolved innate-inflammatory process that might account for disease progression

    Thermal photons in QGP and non-ideal effects

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    We investigate the thermal photon production-rates using one dimensional boost-invariant second order relativistic hydrodynamics to find proper time evolution of the energy density and the temperature. The effect of bulk-viscosity and non-ideal equation of state are taken into account in a manner consistent with recent lattice QCD estimates. It is shown that the \textit{non-ideal} gas equation of state i.e ϵ3P0\epsilon-3\,P\,\neq 0 behaviour of the expanding plasma, which is important near the phase-transition point, can significantly slow down the hydrodynamic expansion and thereby increase the photon production-rates. Inclusion of the bulk viscosity may also have similar effect on the hydrodynamic evolution. However the effect of bulk viscosity is shown to be significantly lower than the \textit{non-ideal} gas equation of state. We also analyze the interesting phenomenon of bulk viscosity induced cavitation making the hydrodynamical description invalid. We include the viscous corrections to the distribution functions while calculating the photon spectra. It is shown that ignoring the cavitation phenomenon can lead to erroneous estimation of the photon flux.Comment: 11 pages, 13 figures; accepted for publication in JHE

    Beneficial impacts of biochar as a potential feed additive in animal husbandry

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    In the last decade, biochar production and use have grown in popularity. Biochar is comparable to charcoal and activated charcoal because it is a pyrogenic carbonaceous matter made by pyrolyzing organic carbon-rich materials. There is a lack of research into the effects of adding biochar to animal feed. Based on the reviewed literature, including its impact on the adsorption of toxins, blood biochemistry, feed conversion rate, digestion, meat quality, and greenhouse gas emissions, adding biochar to the diet of farm animals is a good idea. This study compiles the most important research on biochar's potential as a supplement to the diets of ruminants (including cows and goats), swine, poultry, and aquatic organisms like fish. Biochar supplementation improves animal growth, haematological profiles, meat, milk and egg yield, resistance to illnesses (especially gut pathogenic bacteria), and reduced ruminant methane emission. Biochar's strong sorption capacity also helps efficiently remove contaminants and poisons from the animals' bodies and the farm surroundings where they are raised. Animal farmers are predicted to make greater use of biochar in the future. Biochar could potentially be of value in the healthcare and human health fields; hence research into this area is encouraged. The present review highlights the potential benefits of biochar as an additive to animal feed and demonstrates how, when combined with other environmentally friendly practices, biochar feeding can extend the longevity of animal husbandry

    Properties of the nuclear medium

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    We review our knowledge on the properties of the nuclear medium that have been studied, along many years, on the basis of many-body theory, laboratory experiments and astrophysical observations. First we consider the realm of phenomenological laboratory data and astrophysical observations, and the hints they can give on the characteristics that the nuclear medium should possess. The analysis is based on phenomenological models, that however have a strong basis on physical intuition and an impressive success. More microscopic models are also considered, and it is shown that they are able to give invaluable information on the nuclear medium, in particular on its Equation of State. The interplay between laboratory experiments and astrophysical observations are particularly stressed, and it is shown how their complementarity enriches enormously our insights into the structure of the nuclear medium. We then introduce the nucleon-nucleon interaction and the microscopic many-body theory of nuclear matter, with a critical discussion about the different approaches and their results. The Landau Fermi Liquid theory is introduced and briefly discussed. As illustrative example, we discuss neutron matter at very low density, and it is shown how it can be treated within the many-body theory. A section is dedicated to the pairing problem. The connection with nuclear structure is then discussed, on the basis of the Energy Density Functional method. The possibility to link the physics of exotic nuclei and the astrophysics of neutron stars is particularly stressed. Finally we discuss the thermal properties of the nuclear medium, in particular the liquid-gas phase transition and its connection with the phenomenology on heavy ion reactions and the cooling evolution of neutron stars. The presentation has been taken for non-specialists and possibly for non-nuclear physicists.Comment: 90 pages, 29 figures, revised versio

    Tricuspid Valve Academic Research Consortium Definitions for Tricuspid Regurgitation and Trial Endpoints.

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    Interest in the pathophysiology, etiology, management, and outcomes of patients with tricuspid regurgitation (TR) has grown in the wake of multiple natural history studies showing progressively worse outcomes associated with increasing TR severity, even after adjusting for multiple comorbidities. Historically, isolated tricuspid valve surgery has been associated with high in-hospital mortality rates, leading to the development of transcatheter treatment options. The aim of this first Tricuspid Valve Academic Research Consortium document is to standardize definitions of disease etiology and severity, as well as endpoints for trials that aim to address the gaps in our knowledge related to identification and management of patients with TR. Standardizing endpoints for trials should provide consistency and enable meaningful comparisons between clinical trials. A second Tricuspid Valve Academic Research Consortium document will focus on further defining trial endpoints and will discuss trial design options

    Tricuspid Valve Academic Research Consortium Definitions for Tricuspid Regurgitation and Trial Endpoints.

    Get PDF
    Interest in the pathophysiology, etiology, management, and outcomes of patients with tricuspid regurgitation (TR) has grown in the wake of multiple natural history studies showing progressively worse outcomes associated with increasing TR severity, even after adjusting for multiple comorbidities. Historically, isolated tricuspid valve surgery has been associated with high in-hospital mortality rates, leading to the development of transcatheter treatment options. The aim of this first Tricuspid Valve Academic Research Consortium document is to standardize definitions of disease etiology and severity, as well as endpoints for trials that aim to address the gaps in our knowledge related to identification and management of patients with TR. Standardizing endpoints for trials should provide consistency and enable meaningful comparisons between clinical trials. A second Tricuspid Valve Academic Research Consortium document will focus on further defining trial endpoints and will discuss trial design options

    Flow in heavy-ion collisions - Theory Perspective

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    I review recent developments in the field of relativistic hydrodynamics and its application to the bulk dynamics in heavy-ion collisions at the Relativistic Heavy- Ion Collider (RHIC) and the Large Hadron Collider (LHC). In particular, I report on progress in going beyond second order relativistic viscous hydrodynamics for conformal fluids, including temperature dependent shear viscosity to entropy density ratios, as well as coupling hydrodynamic calculations to microscopic hadronic rescattering models. I describe event-by-event hydrodynamic simulations and their ability to compute higher harmonic flow coefficients. Combined comparisons of all harmonics to recent experimental data from both RHIC and LHC will potentially allow to determine the desired details of the initial state and the medium properties of the quark-gluon plasma produced in heavy-ion collisions.Comment: 8 pages, Invited plenary talk at the 22nd International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2011), May 23-28 2011, Annecy, Franc

    Sensory and nutritional evaluation of nine types of millet substituted for polished white rice in select Indian meal preparations

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    This study was conducted to test the suitability of using nine types of millets namely finger millet, pearl millet, white and yellow sorghum, little millet, barnyard millet, proso millet, kodo millet, and browntop millet in seven popular Indian meal preparations based on sensory characteristics and nutrient value. The popular Indian meal preparations tested were boiled grain, dosa, idli, bisi belle bath, pulao, puttu, and pongal. In total, 53 variations in meal preparations were developed using the millets and seven polished white rice-based meal preparations were developed as control. The main findings indicated that meal preparation crafted from various millets garnered overall sensory scores closely resembling to those derived from polished white rice. Notably, little millet exhibited high scores in pongal and dosa, and achieved elevated overall sensory scores compared to meal preparation from polished white rice. Bisi belle bath made of barnyard millet scored higher in overall sensory score than polished white rice. Moreover, there was significant association between some types of millets’ overall sensory characteristics (p < 0.005) with polished white rice-based meal preparations. In terms of nutrient value, all the millet-based meal preparations had significantly high nutritional value compared to those made with polished white rice (p < 0.05). Especially calcium content of the meal prepared with finger millet was significantly higher compared to polished white rice-based meals (p < 0.05). Puttu, idli, and dosa prepared with finger millet had calcium content of 59.4, 10.8, and 70.9 mg/100 g compared to those prepared with the polished white rice which had only 1.3, 6.3, and 9.2 mg/100 g. The magnesium content of all millet-based meal preparations was generally several-folds higher compared to the polished white rice-based meal preparations (p < 0.05). There is a significant difference in the fiber content of the meals prepared with millets compared to the meals prepared with polished white rice (p < 0.05). This study was conducted using millets that are locally available and does not represent all the millet varieties available globally, as each type of millet has a wide range of varieties. Therefore, it is important to understand and choose the type and variety of millet while enhancing the nutritional value of diets
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