An approximate determination of the characteristic velocity losses and the positioning of the end of the launching phase of the first stages of launch vehicles

2021 ◽  
Author(s):  
L. P. Muhamedov ◽  
D. A. Kirievskii
Keyword(s):  
Approximate Determination ◽  
Characteristic Velocity ◽  
Launch Vehicles

The harmonic and transient electromagnetic response of a thin dipping dike

Geophysics ◽  
1983 ◽  
Vol 48 (7) ◽  
pp. 934-952 ◽  
Author(s):  
P. Weidelt
Keyword(s):  
Formal Solution ◽  
Harmonic Excitation ◽  
Electromagnetic Response ◽  
Approximate Determination ◽  
Finite Conductivity ◽  
Circular Loop ◽  
Decay Modes ◽  
Transient Electromagnetic ◽  
Free Decay

An exact solution is given for the electromagnetic induction in a dipping dike of finite conductivity, represented as a thin half‐sheet in a nonconducting surrounding. The problem is formulated for arbitrary dipole or circular loop [Formula: see text] configurations. The formal solution obtained by the Wiener‐Hopf technique is cast into a rapidly convergent triple integral suitable for an effective numerical treatment. A good agreement is found between numerical results and analog measurements available for harmonic excitation. The transient response is obtained as a superposition of the half‐sheet free‐decay modes and is illustrated by some numerical examples for coincident loops, including a diagram for the approximate determination of conductance and depth of a vertical dike.

Caracterización de la roca mediante propiedades físicas y su relación con la resistencia a la compresión simple

2021 ◽  
Vol 2 (4) ◽  
pp. 5081-5093
Author(s):  
Patricio Feijoo Calle ◽  
Elizabeth Brito Verdezoto
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Unconfined Compressive Strength ◽  
Approximate Determination ◽  
Practical Application ◽  
Calculation Methodology

En este trabajo se propone una metodología sencilla y de aplicación práctica en campo para la determinación aproximada de la Resistencia a la Compresión Simple (RCS) en rocas, propiedad o característica que es importante en minería, ya que mediante la misma, se ejecutan análisis para la valoración de factores de seguridad y estabilidad y/o posibles sistemas de fortificación en las obras o estructuras mineras, a más de que la caracterización de la RCS es también influyente en el uso de explosivos para la explotación o extracción de materiales de una cantera o mina. Esta estimación se la propone en base a la determinación de las siguientes tres propiedades de la roca, que en esta investigación las denominamos densidad, porosidad y absorción “en mina”. Estas propiedades físicas se las puede obtener de una forma simple, pero metódica y en este trabajo se han ejecutado ensayos sobre un mismo material o roca proveniente de la zona de Cojitambo, provincia del Cañar (Ecuador) y sobre una base de 60 muestras o probetas. Los resultados obtenidos permiten una correlación entre las propiedades antes descritas y la RCS, a más que se ha estructurado una metodología de cálculo para el objetivo planteado.   This work proposes a simple methodology and practical application in the field for the approximate determination of the Unconfined Compressive Strength (UCS) in rocks, property or characteristic that is important in mining, since through it analyzes are carried out to the assessment of security and stability factors and/or possible fortification systems in the works or mining structures, in addition to the characterization of the UCS is also influential in the use of explosives for the exploitation or extraction of materials from a quarry or mine. This estimate is proposed based on the determination of the following three properties of the rock, which in this investigation we call density, porosity and absorption “in mine”. These physical properties can be obtained in a simple, but methodical way and in this work, tests have been carried out on the same material or rock from the Cojitambo area, Cañar province (Ecuador) and on the basis of 60 samples or test tubes. The results obtained allow a correlation between the properties described above and the UCS, in addition to a calculation methodology for the proposed objective.

Determinação aproximada de chuvas intensas no leste do paraná através da estatística e da álgebra pseudo real / Approximate determination of heavy rain in east paraná through statistics and pseudo real algebra

2021 ◽  
Vol 4 (3) ◽  
pp. 2966-2976
Author(s):  
Carlos Pereira De Novaes
Keyword(s):  
Heavy Rain ◽  
Approximate Determination ◽  
Real Algebra

Este artigo foi elaborado para se mostrar como se pode utilizar a álgebra pseudo-real em correlações usando dados de precipitações intensas de localidades da região leste do Estado do Paraná, de forma a se obter equações de chuvas intensas aproximadas para uso em engenharia de recursos hídricos e aqui vamos analisar uma equação aproximada geral de chuvas intensas para esta região com dados de chuvas intensas obtidas no livro Chuvas Intensas no Brasil correlacionando-as através do uso da estatística pseudo real com as latitudes, as longitudes e as precipitações médias anuais obtidas pela internet.

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