Search results for "Gauge"
showing 10 items of 710 documents
Is massless quantum electrodynamics a free-field theory?
1976
It is shown that if the photon wave-function renormalization constant is finite, then in the limit of zero fermion mass, quantum electrodynamics is a free- field theory.
Investigating the changes in extreme rainfall series recorded in an urbanised area
2002
The aim of this study is to investigate and quantify changes in the rainfall regime of the metropolitan area of Palermo characterised by increasingly strong urbanisation. The rainfall data, considered in this study, were collected on a yearly basis from eight rain gauges within and outside the metropolitan area of Palermo, Sicily, Italy. A preliminary analysis made on the annual total rainfall depths showed a global reduction of total annual rainfall, with two different trends: more regular for the series observed in the rain gauges within the urbanised area and more variable for the series observed in the rain gauges outside the area. A further analysis has been performed using the series …
Plant-based water stress sensing in two olive cultivars with different physiological responses to drought
2022
A large portion of modern olive plantings is dominated by one main cultivar (‘Arbequina’) planted at super high density (SHD, 1,500 tree ha‑1), leading to a dangerous reduction in olive biodiversity. Very few cultivars have growth and productive patterns that suit the SHD system requirements. Partial intensification and mechanization with several cultivars may represent the safest and easiest alternative. The efficient use of limited natural resources, such as water, in SHD systems, requires precise management. Continuous plant-based sensing is a promising approach to managing water, mainly tested on the cultivar ‘Arbequina’. In this study, we evaluated the sensitivity of two promising indi…
Monopoles and dualities in 3d N=2 quivers
2021
Seiberg-like dualities in 2+1d quiver gauge theories with 4 supercharges are investigated. We consider quivers made of various combinations of classical gauge groups U(N), Sp(N), SO(N) and SU(N). Our main focus is the mapping of the supersymmetric monopole operators across the dual theories. There is a simple general rule that encodes the mapping of the monopoles upon dualizing a single node. This rule dictates the mapping of all the monopoles which are not dressed by baryonic operators. We also study more general situations involving baryons and baryon-monopoles, focussing on three examples: SU−Sp, SO−SO and SO−Sp quivers.
Geostatistical techniques for runoff mapping: an application to Sicily, Italy
2011
The availability of reliable and long time series of runoff data is fundamental for most of the hydrological analyses and for the assessment and the management of water resources even in condition of global climatic change. However, hydrologic data sets are often characterized by a short duration and also suffer from missing data values, mainly due to malfunctioning of gauging stations for a specific period. In order to overcome this problem and obtain long and continuous runoff time series, different models and methods have been previously developed and proposed. While some models, used to extent the streamflow record, are conceptual, empirical, regressive models based on the rainfall inpu…
Advances in Strain Gauge Measurement on Composite Materials
2010
This article gives an overview on the application of strain gauge techniques to the analysis of the strains in composite materials. The orthotropic behaviour of the composite influences the performance of strain gauges that are calibrated for use on isotropic materials. The article considers therefore the typical topics of the strain gauge technology applied to composites with particular reference to the compensation of thermal output, the measurement of the coefficients of thermal expansion, the determination of the strain and stress state, the influence of the misalignment error, the reinforcement effect, the determination of the stress intensification factor, the analysis of residual str…
The Reinforcement Effect of Strain Gauges Embedded in Low Modulus Material
2013
The reinforcement effect of electrical resistance strain gauges is well-described in the literature, especially for strain gauges installed on surface. This paper considers the local reinforcement effect of strain gauges embedded within low Young modulus materials. In particular, by using a simple theoretical model, already used for strain gauges installed on the surface, it proposes a simple formula that allows the user to evaluate the local reinforcement effect of a generic strain gauge embedded on plastics, polymer composites, etc. The theoretical analysis has been integrated by numerical and experimental analyses, which confirmed the reliability of the proposed model.
The zitterbewegung interpretation of quantum mechanics as theoretical framework for ultra-dense deuterium and low energy nuclear reactions
2017
This paper introduces a Zitterbewegung model of the electron by applying the principle of Occam's razor to the Maxwell's equations and by introducing a scalar component in the electromagnetic field. The aim is to explain, by using simple and intuitive concepts, the origin of the electric charge and the electromagnetic nature of mass and inertia. The Zitterbewegung model of the electron is also proposed as the best suited theoretical framework to study the structure of Ultra-Dense Deuterium (UDD), the origin of anomalous heat in metal-hydrogen systems and the possibility of existence of "super-chemical" aggregates at Compton scale.
The electron and Occam's razor
2017
This paper introduces a Zitterbewegung (ZBW) model of the electron by applying the principle of Occam’s razor to Maxwell’s equations and by introducing a scalar component in the electromagnetic field. The aim is to explain, by using simple and intuitive concepts, the origin of the electric charge and the electromagnetic nature of mass and inertia. A ZBW model of the electron is also proposed as the best suited theoretical framework to study the structure of Ultra-Dense Deuterium (UDD), the origin of anomalous heat in metal–hydrogen systems and the possibility of existence of “super-chemical” aggregates at Compton scale.
Maxwell’s Equations and Occam’s Razor
2017
In this paper a straightforward application of Occam’s razor principle to Maxwell’s equation shows that only one entity, the electro-magnetic four-potential, is at the origin of a plurality of concepts and entities in physics. The application of the so called “Lorenz gauge” in Maxwell’s equations denies the status of real physical entity to a scalar field that has a gradient in space-time with clear physical meaning: the four-current density field. The mathematical formalism of space-time Clifford algebra is introduced and then used to encode Maxwell’s equations starting only from the electromagnetic four-potential. This approach suggests a particular Zitterbewegung (ZBW) model for charged …