7,128 research outputs found
APPENDIX_I – Supplemental material for Explicit and implicit experience of own’s body in painful musculoskeletal disorders and rheumatic diseases: A scoping review protocol of available quantitative and qualitative evidence
No full textSupplemental material, APPENDIX_I for Explicit and implicit experience of own’s body in painful musculoskeletal disorders and rheumatic diseases: A scoping review protocol of available quantitative and qualitative evidence by Antonello Viceconti, Eleonora Maria Camerone, Deborah Luzzi, Matteo Pardini, Diego Ristori, Alberto Gallace and Marco Testa in SAGE Open Medicine</p
Molecular interpretation of nonclassical gas dynamics of dense vapors under the van der Waals model
No full textThe van der Waals polytropic gas model is used to investigate the role of attractive and repulsive intermolecular forces and the influence of molecular complexity on the possible nonclassical gas dynamic behavior of vapors near the liquid-vapor saturation curve. The decrease of the sound speed upon isothermal compression is due to the well-known action of the van der Waals attractive forces and this effect is shown here to be comparatively larger for more complex molecules with a large number of active vibrational modes; for these fluids isentropic flows are in fact almost isothermal. Contributions to the speed of sound resulting from intermolecular forces and the role of molecular complexity are analyzed in details for both isothermal and isentropic transformations. Results of the exact solution to the problem of a finite pressure perturbation traveling in a still fluid are presented in three exemplary cases: ideal gas, dense gas and nonclassical gas behavior. A classification scheme of fluids based on the possibility of exhibiting different gas dynamic behaviors is also proposed.Process and EnergyMechanical, Maritime and Materials Engineerin
Point Explosions in Dense Gases
No full textThe work hereby presented is part of a project currently underway at the Energy Technology section, TU Delft, aimed at the experimental proof of nonclassical gasdynamic effects in BZT fluids. One of the ideas under scrutiny is to employ a recently developed experimental technique to generate and visualize spherical compression waves in a BZT gas. Flow simulations were performed to evaluate the potential of using this experimental arrangement to investigate the formation and propagation of nonclassical waves. Results of D6 (dodecamethylcyclohexasiloxane) flow field computations generated by point explosions are hereby presented and show that the spreading of the nonclassical compression can be hardly detected by means of optical measurements. An alternative experimental technique, i.e. total pressure measurements at different locations, is briefly discussed
Nel X Centenario della Traslazione di S. Matteo a Salerno 954-1954
No full textLa Società Salernitana di Storia Patria aderisce al progetto EleA e autorizza la pubblicazione del fascicolo.Esemplare posseduto dalla Biblioteca Provinciale di Salerno.A.16-17 (1955-1956): G. Ricciotti, San Matteo e il suo Vangelo, P. 3 ; S. Garofano, L’Evangelo aramaico di S. Matteo, P. 11 ; A. Vaccari, La tradizione manoscritta de Vangelo di S. Matteo, P. 29 ; C. Pedicini, Il Vangelo di S. Matteo nella Patristica occidentale, P. 38 ; E. Pontieri, Salerno«Civitas Sancti Matthaei» – Il culto di S. Matteo in Salerno medioevale, P. 63 ; E. Pontieri, La dinamica interna della storia del Principato longobardo di Salerno, P. 109 ; M. Fuiano, Alfano, Arcivescovo di Salerno, innografo di S. Matteo, P. 141 ; S. Bottari, Sul complesso monumentale di S. Matteo in Salerno – Rapporti tra l’architettura siciliana e quella campana nel Medioevo, P. 157 ; G. Galassi, I musaici del Duomo di Salerno, P. 181 ; L. De Rosa, La fiera di S. Matteo: una fiera di cambi, P. 191
Minimization of the Thermal Transmittance of Masonry Blocks by Topology Optimization
No full textA contribution toward the thermal insulation of masonry buildings is given in this paper, assuming the heat flux across any wall to be uniform along its height and seeking the optimal geometry of the cross-section of any block forming the wall. The minimization of the thermal transmittance of the block is dealt with as a topology optimization problem. Constraints on the mechanical properties of the blocks are also prescribed, to allow for the presence of in-plane and out-of-plane loads. A parametric
investigation is carried out to investigate the effects of the design constraints and the geometry of the boundary of the block on their optimal layout. The thermal efficiency of the optimized units is also compared with that of standard blocks, showing that topology optimization may be conveniently adopted to improve the thermomechanical performance of conventional layouts
35329_Appendix – Supplemental material for Epidemiology of Anterior Cruciate Ligament Injury in Italian First Division Soccer Players
No full textSupplemental material, 35329_Appendix for Epidemiology of Anterior Cruciate Ligament Injury in Italian First Division Soccer Players by Alberto Grassi, Luca Macchiarola, Matteo Filippini, Gian Andrea Lucidi, Francesco Della Villa and Stefano Zaffagnini in Sports Health: A Multidisciplinary Approach</p
Admissibility region for rarefaction shock waves in dense gases
No full textIn the vapour phase and close to the liquid–vapour saturation curve, fluids made of complex molecules are expected to exhibit a thermodynamic region in which the fundamental derivative of gasdynamic ? is negative. In this region, non-classical gasdynamic phenomena such as rarefaction shock waves are physically admissible, namely they obey the second law of thermodynamics and fulfil the speed-orienting condition for mechanical stability. Previous studies have demonstrated that the thermodynamic states for which rarefaction shock waves are admissible are however not limited to the ? <0 region. In this paper, the conditions for admissibility of rarefaction shocks are investigated. This results in the definition of a new thermodynamic region – the rarefaction shocks region – which embeds the ? <0 region. The rarefaction shocks region is bounded by the saturation curve and by the locus of the states connecting double-sonic rarefaction shocks, i.e. shock waves in which both the pre-shock and post-shock states are sonic. Only one double-sonic shock is shown to be admissible along a given isentrope, therefore the double-sonic states can be connected by a single curve in the volume–pressure plane. This curve is named the double sonic locus. The influence of molecular complexity on the shape and size of the rarefaction shocks region is also illustrated by using the van der Waals model; these results are confirmed by very accurate multi-parameter thermodynamic models applied to siloxane fluids and are therefore of practical importance in experiments aimed at proving the existence of rarefaction shock waves in the single-phase vapour region as well as in future industrial applications operating in the non-classical regime.Process and EnergyMechanical, Maritime and Materials Engineerin
Critical point anomalies include expansion shock waves
No full textFrom first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the result is valid for any common pure fluid in which molecular interactions are only short-range, namely, for so-called 3-dimensional Ising-like systems, and under the assumption of thermodynamic equilibrium.In addition to rarefaction shock waves, diverse non-classical effects are admissible, including composite compressive shock-fan-shock waves, due to the change of sign of the fundamental derivative of gasdynamics.Aerodynamics, Wind Energy, Flight Performance and PropulsionAerospace Engineerin
The influence of molecular complexity on expanding flows of ideal and dense gases
No full textThis paper presents an investigation about the effect of the complexity of a fluid molecule on the fluid dynamic quantities sound speed, velocity, and Mach number in isentropic expansions. Ideal-gas and dense-gas expansions are analyzed, using the polytropic ideal gas and Van der Waals thermodynamic models to compute the properties of the fluid. In these equations, the number of active degrees of freedom of the molecule is made explicit and it is taken as a measure of molecular complexity. The obtained results are subsequently verified using highly accurate multiparameter equations of state. For isentropic expansions, the Mach number does not depend on the molecular weight of the fluid but only on its molecular complexity and pressure ratio. Remarkably enough, the Mach number can either increase or decrease with molecular complexity, depending on the considered pressure ratio. The exit speed of sound and flow velocity, however, are dependent on both molecular complexity and weight, as well as on the inlet total temperature. The exit flow velocity is found to be a monotonically increasing function of molecular complexity for all expansion ratios, whereas the speed of sound monotonically increases with molecular complexity only at high pressure ratios. The speed of sound is not monotone for pressure ratios around 3, which leads to the Mach number being nonmonotone at pressure ratios around 10. It should be noted that the sound speed and flow velocity depend much more strongly on molecular weight than on molecular complexity, which in realistic expansions often obscures the influence of the latter. Quantitative differences are observed between ideal and dense-gas expansions, which are dependent on the reduced inlet conditions. The present study concludes with the numerical simulation of two-dimensional expansions in a turbine nozzle to document the occurrence of real-gas effects and their dependence on molecular complexity in realistic applications.Process and EnergyMechanical, Maritime and Materials Engineerin
Siloxanes: A new class of candidate Bethe-Zel’dovich-Thompson fluids
No full textThis paper presents a new class of Bethe-Zel’dovich-Thompson fluids, which are expected to exhibit nonclassical gasdynamic behavior in the single-phase vapor region. These are the linear and cyclic siloxanes, light silicon oils currently employed as working fluids in organic Rankine cycle turbines. State-of-the-art multiparameter equations of state are used to describe the thermodynamic properties of siloxanes and to compute the value of the fundamental derivative of gasdynamics ?, whose negative sign is the herald of nonclassical gasdynamics. Siloxane fluids starting from D6 and cyclic siloxanes of greater complexity, and MD3M and linear siloxanes of greater complexity are predicted to exhibit a thermodynamic region in which ? is negative and hence nonclassical wavefields are admissible. As an exemplary case, a nonclassical rarefaction shock wave propagating in fluid D6 is studied to demonstrate the possibility of using siloxane fluids in nonclassical gasdynamic applications and to experimentally verify the existence of nonclassical wavefields in the vapor phase. The sensitivity of the present results to the considered thermodynamic model of the fluid is also briefly discussed.Process and EnergyMechanical, Maritime and Materials Engineerin
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