Search results for "Pressure"
showing 10 items of 4493 documents
Non-equilibrium melting of colloidal crystals in confinement
2009
International audience; We report on a novel and flexible experiment to investigate the non-equilibrium melting behaviour of model crystals made from charged colloidal spheres. In a slit geometry polycrystalline material formed in a low salt region is driven by hydrostatic pressure up an evolving gradient in salt concentration and melts at large salt concentration. Depending on particle and initial salt concentration, driving velocity and the local salt concentration complex morphologic evolution is observed. Crystal-melt interface positions and the melting velocity are obtained quantitatively from time resolved Bragg- and polarization microscopic measurements. A simple theoretical model pr…
Drying and Compression under Confining Pressure Effects on Structural Rearrangement of Wood
1996
Regional blood flow in deep structures of the brain measured in acute cat experiments by means of a new beta-sensitive semiconductor needle detector.
1967
Regional cerebral blood flow was measured by means of isotope clearance with a new type of solid state beta-sensitive needle detector (diameter 0.9 mm) introduced into the brain tissue in acute cat experiments. The flow values obtained within the cortex were compared with values recorded above the same cortical region with the same needle detector, or with a small GM-tube. The insertion of the needle detector into the brain tissue gave rise to injury (checked histologically) which deformed the clearance curves in a manner suggesting that the normal circulation had been destroyed within the tissue from which the measurements were made.
Dense nanostructured materials obtained by spark plasma sintering and field activated pressure assisted synthesis starting from mechanically activate…
2004
The preparation of highly dense bulk materials with a grain size in the range of a few to a few hundreds nanometers is currently the objective of numerous studies. In our research we have achieved a measure of success in this regard by using the methods of mechanically-activated, field-activated, pressure-assisted synthesis, MAFAPAS, which has been patented, and mechanically-activated spark plasma sintering, MASPS. Both methods, which consist of the combination of a mechanical activation step followed by a consolidation step under the simultaneous influence of an electric field and mechanical pressure, have led to the formation of dense nanostructured ceramics, intermetallics, and composite…
On the thermal-hydraulic performances of the DEMO divertor cassette body cooling circuit equipped with a liner
2020
Abstract In the framework of the Work Package DIV 1 - “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by University of Palermo and ENEA to investigate the steady-state thermal-hydraulic performances of the DEMO divertor cassette cooling system. The research activity has been focussed onto the most recent design of the Cassette Body (CB) cooling circuit, consistent with the DEMO baseline 2017 and equipped with a liner, whose main function is to protect the underlying vacuum pump CB opening from plasma radiation. The research campaign has been carried out following a theoretical-computational approach based on the finite vo…
Thermal-hydraulic optimisation of the DEMO divertor cassette body cooling circuit equipped with a liner
2019
Abstract Within the framework of the Work Package DIV 1 - “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by University of Palermo and ENEA to investigate the thermal-hydraulic performances of the DEMO divertor cassette cooling system. The research activity has been focused onto the most recent design of the Cassette Body (CB) cooling circuit equipped with a Liner, whose main function is to protect the underlying vacuum pump hole from the radiation arising from the plasma. The research campaign has been carried out following a theoretical-computational approach based on the Finite Volume Method and adopting the commercial…
Deformation analysis of ATHENA test filters made of plastic thin films supported by a mesh under differential static pressure
2019
Within ESA Cosmic Vision 2015-2025 Science Program, ATHENA was selected to be a Large-class high energy astrophysics space mission. The observatory will be equipped with two interchangeable focal plane detectors named X-Ray Integral Field Unit (X-IFU) and Wide Field Imager (WFI). In order to optimally exploit the detector sensitivity, X-ray transparent filters are required. Such filters need to be extremely thin to maximize the X-ray transparency, that is, no more than a few tens of nm, still they must be able to sustain the severe stresses experienced during launch. Partially representative test filters were made with a thin polypropylene film, coated with Ti, and supported by a thin highl…
Erratum: “Enhanced acoustic pressure sensors based on coherent perfect absorber-laser effect” [J. Appl. Phys. 129, 104902 (2021)]
2021
Ultrasound-assisted bleaching: Mathematical and 3D computational fluid dynamics simulation of ultrasound parameters on microbubble formation and cavi…
2019
Abstract The implementation of ultrasound-assisted bleaching (UAB) is gaining interest in commercial oil refining, as an alternative to the current bleaching procedure (BP), because this technique has several advantages compared to the conventional BP. The mathematical and 3D computational fluid dynamics (CFD) simulation of the influence of ultrasound power, frequency and temperature for predicting microbubble formation and heat transfer in the ultrasonic treatment of soybean oil was assessed in order to optimize the UAB process. The fluctuation frequency and wave speed showed opposite effects on system response to the imposed pressure pulse. As the bubble radius shrinks to zero (after bubb…