2,525 research outputs found

    Glueball production in hadron and nucleus collisions

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    We elaborate on the hypothesis that in high energy hadron hadron and nucleus nucleus collisions the lowest mass glueballs are copiously produced from the gluon rich environment especially at high energy density. We discuss the particular glueball decay modes: 0++,2++→KKˉ0^{++}, 2^{++} \to K \bar{K} and 0++→π+π−ℓ+ℓ−0^{++} \to \pi^{+} \pi^{-} \ell^{+} \ell^{-}.Comment: 14 pages, six figure

    Focus-stacking system for 3D acquisition of sculptures and archaeological manufacts

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    In this paper we present the basic features of the Shape from Focus techniques and discuss the potentiality of its application in the 3D imaging of small sculptures and archaeological manufacts. A scanning system for optimizing the image stack acquisition in laboratory was assembled, while 3D reconstruction was done in ImageJ

    A high-fat, high-glycaemic index, low-fibre dietary pattern is prospectively associated with type 2 diabetes in a British birth cohort

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    The combined association of dietary fat, glycaemic index (GI) and fibre with type 2 diabetes has rarely been investigated. The objective was to examine the relationship between a high-fat, high-GI, low-fibre dietary pattern across adult life and type 2 diabetes risk using reduced rank regression. Data were from the MRC National Survey of Health and Development. Repeated measures of dietary intake estimated using 5-d diet diaries were available at the age of 36, 43 and 53 years for 1180 study members. Associations between dietary pattern scores at each age, as well as longitudinal changes in dietary pattern z-scores, and type 2 diabetes incidence (n 106) from 53 to 60-64 years were analysed. The high-fat, high-GI, low-fibre dietary pattern was characterised by low intakes of fruit, vegetables, low-fat dairy products and whole-grain cereals, and high intakes of white bread, fried potatoes, processed meat and animal fats. There was an increasing trend in OR for type 2 diabetes with increasing quintile of dietary pattern z-scores at the age of 43 years among women but not among men. Women in the highest z-score quintile at the age of 43 years had an OR for type 2 diabetes of 5·45 (95 % CI 2·01, 14·79). Long-term increases in this dietary pattern, independently of BMI and waist circumference, were also detrimental among women: for each 1 sd unit increase in dietary pattern z-score between 36 and 53 years, the OR for type 2 diabetes was 1·67 (95 % CI 1·20, 2·43) independently of changes in BMI and waist circumference in the same periods. A high-fat, high-GI, low-fibre dietary pattern was associated with increased type 2 diabetes risk in middle-aged British women but not in men

    Hadronic centrality dependence in nuclear collisions

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    The kaon number density in nucleus+nucleus and p+p reactions is investigated for the first time as a function of the initial energy density ϵ\epsilon and is found to exhibit a discontinuity around ϵ\epsilon=1.3 GeV/fm3^3. This suggests a higher degree of chemical equilibrium for ϵ>\epsilon > 1.3 GeV/fm3^3. It can also be interpreted as reflection of the same discontinuity, appearing in the chemical freeze out temperature (T) as a function of ϵ\epsilon. The Nα∼1N^{\alpha \sim 1} dependence of (u,d,s) hadrons, whith N the number of participating nucleons, also indicates a high degree of chemical equilibrium and T saturation, reached at ϵ>\epsilon >1.3 GeV/fm3^3. Assuming that the intermediate mass region (IMR) dimuon enhancement seen by NA50 is due to open charm (DDˉD \bar{D}), the following observation can be made: a) Charm is not equilibrated. b) J/Ψ/DDˉJ/\Psi/D \bar{D} suppression -unlike J/Ψ/DYJ/\Psi/DY- appears also in S+A collisions, above ϵ\epsilon ∼\sim1 GeV/fm3^3. c) Both charm and strangeness show a discontinuity near the same ϵ\epsilon. d) J/ΨJ/\Psi could be formed mainly through ccˉc \bar{c} coalescence. e) The enhancement factors of hadrons with u,d,s,c quarks may be connected in a simple way to the mass gain of these particles if they are produced out of a quark gluon plasma (QGP). We discuss these results as possible evidence for the QCD phase transition occuring near ϵ∼\epsilon \sim 1.3 GeV/fm3^3.Comment: 4 pages, 4 figures, proceedings of Vth International Conference on Strangeness in Quark Matter, 20-25 July 2000, Berkeley, California. To appear in Journal of Physics G: Nuclear and Particle Physic

    Wearable Robotics for Impaired Upper-Limb Assistance and Rehabilitation: State of the Art and Future Perspectives

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    Despite more than thirty-five years of research on wearable technologies to assist the upper-limb and a multitude of promising preliminary results, the goal of restoring pre-impairment quality of life of people with physical disabilities has not been fully reached yet. Whether it is for rehabilitation or for assistance, nowadays robotics is still only used in a few high-tech clinics and hospitals, limiting the access to a small amount of people. This work provides a description of the three major 'revolutions' occurred in the field (end-effector robots, rigid exoskeletons, and soft exosuits), reviewing forty-eight systems for the upper-limb (excluding hand-only devices) used in eighty-nine studies enrolling a clinical population before June 2022. The review critically discusses the state of the art, analyzes the different technologies, and compares the clinical outcomes, with the goal of determine new potential directions to follow

    Infrared exploration of the architectural heritage: from passive infrared thermography to <em>hybrid</em> infrared thermography (HIRT) approach

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    Hasta la fecha, los enfoques sobre la termografía infrarroja han sido considerados, o pasivos, o activos. En este último caso, el flujo de calor se obtiene a través de una fuente de calor no natural. El uso de energía solar ha sido recientemente incorporado al enfoque activo gracias a los estudios multitemporales. En este trabajo, se ilustra un enfoque innovador de la termografía híbrida (HIRT). Se combina tanto el componente de tiempo y la fuente de energía solar para recuperar la información cuantitativa así como la profundidad del defecto. Las imágenes térmicas se obtuvieron mediante el análisis de la fachada de la Iglesia de Santa María Collemaggio (L'Aquila, Italia), mientras que los resultados cuantitativos inherentes a las discontinuidades sub-superficiales se obtuvieron gracias al uso de otras técnicas avanzadas. Los resultados experimentales vinculados al enfoque pasivo (es decir, el proceso de mosaico de las imágenes térmicas) derivan de un conjunto de Iglesias antiguas, también incluidas en el estudio, a fin de explicar cuándo y dónde tiene sentido realizar un proceso híbrido

    Thermal imaging in the 3-5 micron range for precise localization of defects: Application on frescoes at the Sforza Castle

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    Infrared methods are of great importance in nondestructive testing of artworks, allowing a remote and wide-field imaging of interesting hidden features. Here we discuss a workflow based on thermal imaging in the mid infrared 3-5 micron range for the evaluation of subsurface defects in frescoes. Particular attention is payed to obtaining a high resolution (submillimetric) localization of the defects. The transfer of diagnostics techniques into real world applications, is discussed through the proof of concept of the proposed workflow on frescoes at the Sforza Castle (Milan, Italy)

    Stable quark stars beyond neutran stars : can they account for the missing matter ?

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    The structure of a spherically symmetric stable dark 'star' is discussed, at zero temperature, containing 1) a core of quarks in the deconfined phase and antileptons 2) a shell of hadrons in particular nn, pp, Λ\Lambda and Σ−\Sigma^- and leptons or antileptons and 3) a shell of hydrogen in the superfluid phase. If the superfluid hydrogen phase goes over into the electromagnetic plasma phase at densities well below one atom / (10fm)3(10 fm)^{3}, as is usually assumed, the hydrogen shell is insignificant for the mass and the radius of the 'star'. These quantities are then determined approximatively : mass = 1.8 solar masses and radius = 9.2 km. On the contrary if densities of the order of one atom / (10fm)3(10 fm)^{3} do form a stable hydrogen superfluid phase, we find a large range of possible masses from 1.8 to 375 solar masses. The radii vary accordingly from 9 to 1200 km.Comment: 5 pages, 2 figures, contribution to Strange Quark Matter conference, Frankfurt, Germany, Sept. 200
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