Search results for "Principle"
showing 10 items of 1023 documents
Performance analysis of photovoltaic powered dc motor — Propeller system
2015
The application of autonomous directly photovoltaic (PV) powered electro-mechanical has received increasing attention for different applications (e.g. PV water pumping, PV powered cooling of arid climate greenhouses, solar vehicles etc). The PV array output is a nonlinear and time-dependent power supply that varies with solar intensity and cell temperature, so the performance characteristics of the directly PV-powered DC motor — propeller system are very different than when powered by a constant DC voltage. The focus of this work is to do performance analysis of directly PV-powered DC motor — propeller system. Through performance evaluation, it has been observed that power transfer matching…
Off-axis focal shift for rotationally nonsymmetric screens
2009
We report on an analytical formulation for evaluating the amplitude distribution along any line directed toward the geometrical focus of a spherical wave front that passes through a rotationally nonsymmetric diffracting screen. Our formula consists of two factors. The first factor involves the one-dimensional Fourier transform of the projection of the screen function onto the off-axis line. The second factor depends on the inverse distance to the screen and permits us to recognize the existence of focal shift along off-axis lines.
Temas e interpretaciones del derecho sucesorio italiano
2021
El articulo quiere mostrar que las interpretaciones de las instituciones del derecho de sucesiones que consideran el interés familiar, como expresión del principio de solidaridad (cada vez más en una protección patrimonialista de la legitimidad), siempre prevalente sobre todos los demás intereses, ya no pueden ser compartidas, porque la solidaridad no se distingue del personalismo. Modernizar el derecho de sucesiones no significa tener que abdicar en favor del contrato, sino descubrir el valor de la autonomía privada y el potencial del acto de última voluntad. Es la centralidad de la persona humana y no sólo el principio de solidaridad (más aún si se entiende en un sentido patrimonialista) …
L’accertamento del trasferimento d’azienda in caso di cambio di appalto nel rito “Fornero”
2021
Con la sentenza n. 2315/2020 la Suprema Corte ha affermato il principio che l’accertamento dell’anzianità di servizio conseguente ad un trasferimento d’azienda può essere affrontato nell’ambito del rito speciale di impugnazione del licenziamento introdotto dalla L. n. 92/2012. Nella decisione in commento la Corte ha altresì modo di dare continuità all’orientamento per cui la fattispecie traslativa si perfeziona anche in presenza di un mero passaggio di personale in forza di obbligo contrattuale o di legge. Infatti se in un determinato appalto di servizi un imprenditore subentra ad un altro e ne acquisisce il personale e i beni strumentali organizzati (cioè l’azienda), la fattispecie no…
Assessment of Modelling in Mathematics Examination Papers: Ready-Made Models and Reproductive Mathematising
2013
In the Netherlands modelling is integrated into the mathematics curriculum. This chapter describes a study of modelling characteristics in recent mathematics examination papers. Results show that the tasks convey the message that mathematics can be found in unexpected situations. In many tasks a situation and a ready-made model are given and students are asked to work with the model. For mathematising, two design principles were: to finalise the parameters of a given model, and to reconstruct a given mathematical model from verbal descriptions and diagrams of a situation. These formats were coined as mechanistic and reproductive mathematising respectively. These formats have been introduced…
Virtual reality as a recovering environment - Implications for design principles
2020
In this study, a simulated, VR-based environment was built and analyzed to explore if a VR environment can possess recovering effects. 61 university students tested a VR application depicting a forest and answered survey questions about the experience. The results showed that VR-environment can indeed have recovering effects. Moreover, when comparing to previous studies in real forests, the recovery effects were at similar levels. The study results suggest that as the VR-based environments can possess recovery effects, they can work as recovery environments at schools or similar environments. The study results offer implications for the designers and propose design principles to build recov…
THE SCUOLA OFFICINA MECCANICA IN VILLAGGIO MONTE DEGLI ULIVI IN RIESI. READING AND ANALYSIS THROUGH SURVEYING.
2017
This research analyses in depth the project of one of the most representative work of the Modern Architectural Movement in Sicily – the Scuola Officina Meccanica, located in Villaggio Monte degli Ulivi, in Riesi (CL), designed by the architect Leonardo Ricci between 1962 and 1968. The main objective is to contribute to the conservation of the architectural work through its analysis and study for a careful and conscious restoration. The research methodology aimed to retrace the compositional and geometric principles that defined the design process and its unique configuration.
Beyond ideal two-dimensional metals: Edges, vacancies, and polarizabilities
2018
Recent experimental discoveries of graphene-stabilized patches of two-dimensional (2D) metals have motivated also their computational studies. However, so far the studies have been restricted to ideal and infinite 2D metallic monolayers, which is insufficient because in reality the properties of such metallic patches are governed by microstructures pervaded by edges, defects, and several types of perturbations. Here we use density-functional theory to calculate edge and vacancy formation energies of hexagonal and square lattices of 45 elemental 2D metals. We find that the edge and vacancy formation energies are strongly correlated and decrease with increasing Wigner-Seitz radii, analogously…
Dynamics of Polymer Melts above the Glass Transition: Monte Carlo Studies of the Bond Fluctuation Model
1997
The bond fluctuation model on the simple cubic lattice with a bond-length dependent potential energy favoring long bonds exhibits a glassy freezing in as the temperature is lowered, many properties being qualitatively similar to experiment. The present paper studies the dynamical properties of the model (as they result from the random hopping algorithm), using configurations of undercooled polymer melts that have been carefully equilibrated by the slithering snake algorithm. In this way quantitatively reliable data can be obtained for distinctly lower temperatures than in the previous work on the dynamics of this model that used the random hopping algorithm for equilibration as well. If var…
Ageing of isotactic polypropylene due to morphology evolution, experimental limitations of realtime density measurements with a gradient column
2006
Abstract Ageing in crystalline polymers is responsible for the deterioration of physical properties leading, for example, to a decrease in toughness and to dimensional changes that are to some extent responsible for warpage and scrap production in injection molding. Since, it depends on the mutual transformation of stable and metastable phases, being always related to changes in morphological organization, it is here preferred to call it ‘Morphological ageing’. Although, one would expect the ageing regime to be determined by the complex morphology with amorphous phases of different mobility and eventually multiple crystalline phases, transformed into each other at an associated transition, …