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Search Results: 1 - 10 of 132940 matches for " Fernando O. Minotti "
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Scalar-tensor theories and asymmetric resonant cavities
Fernando O. Minotti
Physics , 2013, DOI: 10.1134/S0202289313030080
Abstract: Recently published experimental results indicate the appeareance of unusual forces on asymmetric, electromagnetic resonant cavities. It is argued here that a particular class of scalar-tensor theories of gravity could account for this effect.
On the completeness of classical electromagnetism
Fernando O. Minotti
Physics , 2006,
Abstract: The possibility of an incompletness of the equations of electromagnetism is analyzed using a thought experiment that shows a non-physical behavior according to classical electromagnetism. Basically, from Maxwell equations it is shown that a particular passive, isolated circuit could present a transient growth of its currents. Resolution of this problem is sought within the context of the usual electromagnetism and also using the possibly simplest generalization of Maxwell equations, a reduced version of Ohmura equations.
Scalar-tensor theory with enhanced gravitational effects
F. O. Minotti
Physics , 2011,
Abstract: It is shown that a Brans-Dicke scalar-tensor gravitational theory, which also includes Bekenstein's kind of interaction between the Maxwell and scalar fields, has a particular kind of solutions with highly enhanced gravitational effects as compared with General Relativity, prone to laboratory tests.
Longitudinal forces in pinched electric currents
F. O. Minotti
Physics , 2014,
Abstract: It is shown that the theory of Mbelek and Lachi\`eze-Rey predicts longitudinal forces of gravitational origin in pinched current distributions, with magnitudes large enough to have noticeable effects.
Asymptotic probability density functions in turbulence
F. O. Minotti,E. Speranza
Physics , 2007,
Abstract: A formalism is presented to obtain closed evolution equations for asymptotic probability distribution functions of turbulence magnitudes. The formalism is derived for a generic evolution equation, so that the final result can be easily applied to rather general problems. Although the approximation involved cannot be ascertained a priori, we show that application of the formalism to well known problems gives the correct results.
Vibrating Rays Theory
Luis Bilbao,Luis Bernal,Fernando Minotti
Physics , 2014,
Abstract: The present work is aimed to explain why we started to consider Vibrating Rays Theory (VRT) as a viable representation of nature, and to elaborate some of its consequences. In 1846 Faraday introduced the concept of vibrating rays, in which an atom is conceived as having rays that extend to infinity and move with it. According to this point of view, electromagnetic radiative phenomena correspond to vibration of these rays, which propagate at speed c relative to the rays (and the atom). Although a discussion on this subject might seem to be out-of-date, there are many reasons that justified this debate. The first reason is based on the fact that the constancy of the speed of light, irrespective of the source movement, has not been demonstrated experimentally in a conclusive way. In fact, only ballistic emission theories can be discarded by the experimental results. The second reason is based on the fact that study of radiometric data from spacecrafts indicates the existence of different kinds of anomalous Doppler residuals. We will show that these anomalies exhibit a signature of Vibrating Rays Theory. The third reason is related to the time definition in a rotating frame. According to SRT there is not a unique way to assign a time, whereas under VRT no contradictions are present. And finally, that a properly stated Vibrating Rays Theory is compatible with all known experiments on electromagnetism and light propagation. In the present work we will (1) explain how VRT should be interpreted, and why past experiments were misinterpreted, (2) show the characteristics of VRT that are present in spacecraft anomalies, (3) give a possible theoretical model (including the possible presence of longitudinal waves), and (4) describe results in an ongoing experiment designed to distinguish between VRT and SRT models.
Possible measurable effects of light propagating in electromagnetized vacuum, as predicted by a scalar tensor theory of gravitation
T. E. Raptis,F. O. Minotti
Physics , 2013, DOI: 10.1088/0264-9381/30/23/235004
Abstract: The effect of static electromagnetic fields on the propagation of light is analyzed in the context of a particular class of scalar-tensor gravitational theories. It is found that for appropriate field configurations and light polarization, anomalous amplitude variations of the light as it propagates in either a magnetized or electrified vacuum are strong enough to be detectable in relatively simple laboratory experiments.
Hydrodynamic model for the plasma-gas flow in a cutting torch nozzle
Kelly, H.;Minotti, F. O.;Prevosto, L.;Mancinelli, B.;
Brazilian Journal of Physics , 2004, DOI: 10.1590/S0103-97332004000800006
Abstract: we present a simple hydrodynamic model to obtain the profiles of the relevant physical quantities along a nozzle of arbitrary cross-section in a cutting torch. the model uses a two-zone approximation (a hot central plasma carrying the discharge current wrapped by a relatively cold gas which thermally isolates the nozzle wall from the plasma). seeking for a solution with sonic conditions at the nozzle exit, the model allows expressing all the profiles in terms of the externally controlled parameters of the torch (geometry of the torch, discharge current, mass flow of the gas and plenum pressure) and the values of the arc and gas temperatures at the nozzle entrance. these last two values can be estimated simply appealing to energy conservation in the cathode-nozzle region. the model contains additional features compared with previous reported models, while retaining simplicity. the detailed consideration of an arc region coupled to the surrounding gas dynamics allows determining voltage drops and consequent delivered power with less assumptions than those found in other published works, and at the same time reduces the set of parameters needed to determine the solution.
Spectroscopic measurements in a titanium vacuum arc with different ambient gases
Grondona, D.;Kelly, H.;Pelloni, M.;Minotti, F. O.;
Brazilian Journal of Physics , 2004, DOI: 10.1590/S0103-97332004000800005
Abstract: spectral emission lines from a low pressure d-c arc discharge with a ti cathode were studied in various ambient gases; n2, o2, and ar. light from the plasma was detected by an optical spectrometer multichannel analyzer (osma). the spectral intensities of ti, ti+, ar and n2 were measured as a function of the gas pressure in the range 5 × 10-3 - 0.5 mbar. the measurements were performed in the inter-electrode region at different distances from the cathode. for n2 and o2 as the filling gases, the intensities of ti and ti+ increase with the gas pressure up to pressure values of the order of 0:2?0:4 mbar, while they decrease for higher pressure values. with ar gas, a different behavior of the ti+ intensity was found; it presents an increasing general trend. the behavior of the lines was qualitatively analyzed in terms of the most relevant atomic processes that take place in the metallic plasma - gas structure (charge-exchange, electron impact excitation and ionization, etc.). it is found that the behavior of the observed spectral lines can be satisfactorily explained in terms of the relevance of these processes as functions of the neutral gas density and electron temperature.
Previs?o da perda de solo na Fazenda Canchim - SP (EMBRAPA) utilizando geoprocessamento e o USLE 2D
Silva, Fernando das Gra?as Braga da;Minotti, Ricardo Tezini;Lombardi Neto, Francisco;Primavesi, Odo;Crestana, Silvio;
Engenharia Sanitaria e Ambiental , 2010, DOI: 10.1590/S1413-41522010000200006
Abstract: the hydrosedimentological models have an enormous potential in brazil to be the best tool for the estimative of soil lost principally due to their complexity on description of the processes and the robustness that validate them. however, due to a need of a very big volume of required information in connection with the difficulties to adapt the international models and the need of time and structure to create national models, the universal soil lost equation (usle) and its variations still are a reference in brazil to soil lost determination. in this article, a new model to calculate the sl factor, the usle 2d software combined with the idrisi were used. the inedited application was done in southeast cattle breeding embrapa's canchim farm, consisting on the first work of this nature done in this area with such tools. the results obtained were coherent to types of soil, slopes and vegetal cover in the area of study.
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