1,254 research outputs found
DE CORDOVA, Procopio Adolfo F. (Tte. Corl.)
No full textOficio del Tte. Corl. de Caballería, Procopio Adolfo F. de Córdova, al Gral. PEC, Secretario de Guerra y Marina. Le solicita su alta en esa institución y, además, le envía un oficio que le dirigió el Estado Mayor Presidencial idicándole que debe dirigirse a la Secretaría de Guerra y Marina para que se le reconozca el grado que ostenta
Implementation of a digital pathology workflow based on WaidX for rapid remote cytology diagnostics
No full textEvaluation of the field coupling to a line of finite length -A comparison between the dual integral equation approach and the moment method
No full textIn this paper, it is shown that the problem of the electromagnetic field coupling to a line of finite length can be put into "a standard form" of dual integral equations. A general method for solving such dual integral equations is presented and discussed. It basically consists of a transformation of the first kind Fredholm equation into a linear system of algebraic equations by means of a suitable Neumann expansion of the unknown function. This procedure, carried out in the frequency domain, has allowed evaluating the current induced on the line, which has also been computed with the classical method of moment in order to have a validation of the procedure itself
The Effect of a Horizontally Stratified Ground on Lightning Electromagnetic Fields
No full textLRESCI-STI-F
Lightning Potential Index performances in multimicrophysical cloud-resolving simulations of a back-building mesoscale convective system: The Genoa 2014 event
No full textSevere weather events are responsible for hundreds of fatalities and millions of euros of damage every year on the Mediterranean basin. Lightning activity is a characteristic phenomenon of severe weather and often accompanies torrential rainfall, which, under certain conditions like terrain type, slope, drainage, and soil saturation, may turn into flash flood. Building on the existing relationship between significant lightning activity and deep convection and precipitation, the performance of the Lightning Potential Index, as a measure of the potential for charge generation and separation that leads to lightning occurrence in clouds, is here evaluated for the V-shape back-building Mesoscale Convective System which hit Genoa city (Italy) in 2014. An ensemble of Weather Research and Forecasting simulations at cloud-permitting grid spacing (1km) with different microphysical parameterizations is performed and compared to the available observational radar and lightning data. The results allow gaining a deeper understanding of the role of lightning phenomena in the predictability of V-shape back-building Mesoscale Convective Systems often producing flash flood over western Mediterranean complex topography areas. Moreover, they support the relevance of accurate lightning forecasting for the predictive ability of these severe events.SCI-STI-F
A New Channel-Base Lightning Current Formula With Analytically Adjustable Parameters
No full textThe article provides a new channel-based current function, which aims at faithfully reproducing the salient parameters of lightning currents. All the model parameters can be set in a fully analytical way, guaranteeing the possibility of changing them (according to the available measured data) without any numerical procedures. Closed-form solutions of its integral, Fourier transform, and specific energy are proposed, as well as a detailed comparison with the most widely used models, focusing on the advantages of the proposed method. Finally, the specific parameters of the new function to fit with the commonly used measured data sets and standards are provided.SCI-STI-F
Lightning return stroke current identification via field measurements
No full textAn inverse procedure is presented for identifying and reconstructing the waveform of the lightning return stroke current. It is based only on the acquisition of the electromagnetic field radiated by the discharge channel in various locations on the ground and at various frequencies, and requires no information about the channel base current. The fundamental idea is shown to come from an electrostatic problem in which the linear charge density of a vertical thin wire is determined starting from the measured field. Three versions of this procedure have been developed: in the first, the identification is carried out by means of the measurement of the electric field at various distances from the lightning channel at a given frequency; in the second, only two sensors for the electric field are necessary, but various sampling frequencies; in the third, only one observation point is needed, for the measurement of both the electric and the magnetic field. A simulated validation of all the approaches is provided as well as a detailed analysis of their numerical accuracy
Lightning electromagnetic radiation over a stratified conducting ground: Formulation and numerical evaluation of the electromagnetic fields
No full textThe formulation describing the electromagnetic field radiated by a lightning return stroke over a two-layered conducting ground is presented in this paper. The derivation of the Green's functions required to solve the problem is first discussed in detail, and the expressions for the lightning electromagnetic fields are determined. Afterward, an efficient method for the numerical evaluation of the electromagnetic field is proposed. The proposed method is based on a suitable modification of a previously developed model for the evaluation of the fields in the presence of a lossy but homogeneous soil. Particular attention is devoted to the soil reflection coefficient properties, both from a physical and from a mathematical point of view. In part 2 of the paper, the developed approach and numerical algorithms will be used to evaluate the effect of the soil stratification on the radiated fields and to perform the validity assessment of simplified approaches proposed in the literature.SCI-STI-F
New aspects on the role of lipoxygenases in cancer progression
No full textThe Lipoxygenases (LOXs) are a class of
enzymes that convert arachidonic, linoleic, and other
polyunsaturated fatty acid into biologically active
metabolites involved in the inflammatory and immune
responses. Recent evidences indicate that LOXs and the
signaling pathways that are involved in their activation
are also important for carcinogenesis and tumor
progression. LOXs should therefore receive as much
attention from cancer researchers as it has already from
immunologists. In this article, we will review some
evidence that the LOXs pathways affect several aspects
of lung, pancreatic and prostate cancer progression.
Moreover, we discuss how this new perspective on the
roles of LOXs and their metabolites can have important
implications to cancer therapy
A Method for the Improvement of the Stability in FDTD-Based Numerical Codes Evaluating Lightning-Induced Voltage
No full textDealing with realistic networks, the solution of lightning electromagnetic field coupling to transmission lines is generally obtained through a Finite-Difference Time-Domain (FDTD) algorithm interfaced with an electromagnetic simulator. As well known, the stability of the FDTD scheme is determined by the Courant stability condition. In this contribution, it is shown that a second stability condition that limits the ratio between the space step and the line length appears when spatial extrapolation is used to obtain the values of the currents at the line extremities to be interfaced with a transient electromagnetic simulator. Finally, this work aims at solving the aforementioned problem by using a different approach to obtain the currents at the line extremities.SCI-STI-F
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