Theoretical analysis of a monopole antenna with conducting flat disk above the earth

2001 ◽  
Vol 84 (7) ◽  
pp. 27-36
Author(s):  
Aki Yuasa ◽  
Daisuke Itatsu ◽  
Naoki Inagaki ◽  
Nobuyoshi Kikuma
Keyword(s):  
Theoretical Analysis ◽  
Monopole Antenna ◽  
The Earth ◽  
Flat Disk

scholarly journals Amplitude of Sunspot-Dependent Radiocarbon Variations: Data from Corals and Wine

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 111-115
Author(s):  
Mordeckai Magaritz ◽  
Israel Carmi ◽  
Ziv Sirkes
Keyword(s):  
Theoretical Analysis ◽  
Theoretical Calculation ◽  
Production Rate ◽  
Sunspot Cycle ◽  
Published Data ◽  
Earth Surface ◽  
The Earth ◽  
Surface System ◽  
Experimental Values

It has been suggested that the sunspot cycle modulates the production rate of radionuclides in the atmosphere and that these modulations can be traced in various parts of the earth surface system. On the basis of a theoretical analysis, Damon, Sternberg, and Radnell (1983) have concluded that the effects of the 11-yr cycle of sunspots should be observable in 14C data provided the measurements are done at a 2 permil (sd) level. This conclusion is based on calculations using models discussed by Lingenfelter and Ramaty (1970) and by O'Brien (1979) and on the 14C inventory modified from Damon, Lerman, and Long (1978). In this note we compare the amplitude estimate of Damon, Sternberg, and Radnell (1983), who calculated a representative peak-to-peak variation of 1.7‰ in 14C for the sunspot cycle between 1848 and 1856, with experimental values derived from recently published data. We find the experimental value to be larger by a significant factor from the theoretical calculation.

Body waves in a “real Earth”. Part I

1973 ◽  
Vol 63 (1) ◽  
pp. 145-156 ◽  
Author(s):  
A. Cisternas ◽  
O. Betancourt ◽  
A. Leiva
Keyword(s):  
Exact Solution ◽  
Theoretical Analysis ◽  
Power Series ◽  
Arbitrary Number ◽  
Body Waves ◽  
Reflection And Transmission Coefficients ◽  
Earth Model ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
The Earth

abstract A theoretical analysis of body waves in a “real Earth” is presented. The earth model consists of an arbitrary number of spherical liquid and solid layers. The algebraic part of the analysis deals with the way to obtain generalized rays out of the exact solution. It is shown that the Rayleigh matrix, and not the Rayleigh determinant, should be used to expand the solution into a power series of modified reflection and transmission coefficients in order to obtain rays.

scholarly journals Panorama geral das iniciativas de geoconservação do patrimônio geológico internacionais e nacionais / Overview of the initiatives of the geoconservation of international and national geological patrimony

2017 ◽  
Vol 27 (1) ◽  
pp. 1 ◽  
Author(s):  
José Francisco De Araújo Silva ◽  
Cláudia Maria Sabóia de Aquino
Keyword(s):  
Theoretical Analysis ◽  
Scientific Publications ◽  
Human Survival ◽  
The Earth ◽  
The Subject ◽  
International Geological ◽  
Lay Public

<p>Baseando-se no pressuposto de que uma vez destruído o patrimônio geológico não tem como se renovar, perdendo-se desta forma parte da memória da Terra e elementos, muitos deles imprescindíveis à sobrevivência humana, fazem-se urgentes iniciativas de conservação dessa parcela abiótica da natureza, compreendidas como medidas de geoconservação. Diante do exposto, o objetivo deste estudo é apresentar algumas das principais iniciativas de geoconservação adotadas internacionalmente e no Brasil. A metodologia adotada se caracteriza como um ensaio teórico cujas etapas metodológicas compreendem o levantamento bibliográfico; análise teórica e elaboração de reflexões sobre a temática. Por meio deste estudo pôde-se ter uma visão geral referente às iniciativas já adotadas em prol da conservação do patrimônio geológico nacional e internacional, tais como a realização de convenções; criação de grupos e comissões geoconservacionistas; prática de eventos científicos; programas e projetos de geoconservação; publicação de mapas de geodiversidade, livros, documentos, leis e decretos; criação de geoparques; crescente número de publicações científicas sobre o tema, dentre outras ações de geoconservação. Com isso pôde-se constatar que apesar de crescentes no Brasil e em outros países, tais práticas necessitam de estudos mais aprofundados, uma vez que são essenciais para o sucesso da geoconservação no planeta, além disso, foi possível verificar a necessidade de tornar tais ações o mais acessível possível à maior parte do público leigo, o que poderá culminar em uma maior eficácia quando de sua implantação.</p><p><strong>Palavras-chave</strong>: Patrimônio Geológico, Geoconservação, iniciativas.</p><p><strong>Abstract</strong></p><p>Based on the assumption that once the geological patrimony has been destroyed it can't be renewed, thus losing part of the Earth's memory and elements, many of them indispensable to human survival, urgent initiatives are being taken to conserve this abiotic portion of the Earth. Nature, understood as measures of geoconservation. In view of the above, the objective of this study is to present some of the main initiatives of geoconservation adopted internationally and in Brazil. The methodology adopted is characterized as a theoretical essay whose methodological steps include the bibliographic survey; Theoretical analysis and elaboration of reflections on the thematic. Through this study it was possible to have an overview of the initiatives already adopted in favor of the conservation of the national and international geological patrimony, such as the realization of conventions; Creation of geoconservative groups and commissions; Practice of scientific events; Geoconservation programs and projects; Publication of maps of geodiversity, books, documents, laws and decrees; Creation of geoparks; Increasing number of scientific publications on the subject, among other actions of geoconservation. With this in mind, it can be observed that, although they are grown in Brazil and in other countries, these practices require more in-depth studies, since they are essential for the success of geoconservation of the planet. In addition, it was possible to verify the need to make these actions as accessible as possible for the majority of the lay public, which can lead to greater effectiveness at the time of implementation.</p><p><strong>Keywords</strong>: Geological Patrimony, Geoconservation, initiatives.</p>

Theoretical study of methods of finding signals and synchronization of the earth stations of satellite communications

2021 ◽  
pp. 7-14
Author(s):  
A.N. Mursaev ◽  
S.V. Zinkin ◽  
D.A. Novichkov
Keyword(s):  
Theoretical Analysis ◽  
Spread Spectrum ◽  
Theoretical Study ◽  
Clock Synchronization ◽  
Satellite Communications ◽  
Signal Conversion ◽  
The Earth ◽  
Frequency Search ◽  
Decision Circuit ◽  
Spread Spectrum Signals

When using spread-spectrum signals, the problem of searching by frequency and delay must be solved before the signal is processed. For demodulation of simple signals with AM, CHM and FM, it is fundamentally necessary to provide only a frequency search, and clock synchronization can be carried out after the first decision circuit, i.e. in the signal conversion equipment, usually placed in the interface equipment or channel-forming equipment. The paper presents a theoretical analysis of the methods of the search of signals and synchronization in earth stations - search and tracking of singaporemetro signals with an expanded range and features auto scan and auto-tracking frequency when receiving simple signals.

Multi-Mode Narrow-Frame Antenna for 4G/5G Metal-Rimmed Mobile Phones

2020 ◽  
Vol 35 (8) ◽  
pp. 908-915
Author(s):  
Ming Yang ◽  
Yu-Fa Sun ◽  
Tong-Qing Liao
Keyword(s):  
Theoretical Analysis ◽  
Mobile Phones ◽  
Communication Systems ◽  
Return Loss ◽  
Band 3 ◽  
Monopole Antenna ◽  
Experimental Results ◽  
5G Communication ◽  
Multi Mode

A novel multi-mode narrow-frame antenna is presented for 4G/5G metal-rimmed mobile phones in this paper. The proposed antenna is constituted by a monopole antenna and a coupling strip, which is printed on FR4 substrate with thickness of 0.8 mm. The overall area occupied by the antenna is only 60 × 10.4 mm2, which can be used as a promising narrow-frame antenna. The simulated results shows that the return loss of the antenna can provide four operating bandwidths of 822– 961 (band 1), 1697–3075 (band 2), 3280–3835 (band 3) and 4475–5050 MHz (band 4), which respectively cover 824–960, 1710–2690, 3300–3600 and 4800–5000 MHz in 4G/5G communication systems. In order to verify the accuracy of theoretical analysis and simulated results, the proposed antenna is fabricated and measured. The experimental results are basically consistent with the simulated results, suggesting that the presented antenna has attractive performance for mobile phones.

Detection of pre-industrial societies on exoplanets

2020 ◽  
pp. 1-8
Author(s):  
Andrew Lockley ◽  
Daniele Visioni
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Quantitative Analysis ◽  
Theoretical Analysis ◽  
Species Introduction ◽  
The Earth ◽  
Urban Fires ◽  
Near Future ◽  
Industrial Societies ◽  
Significant Effort

Abstract Approximately 22% of sun-like stars have Earth-like exoplanets. Advanced civilizations may exist on these, and significant effort has been expended on the theoretical analysis of planetary systems, and accompanying practical detection instruments. The longevity of technological civilizations is unknown, as is the probability of less advanced societies becoming technological. Accordingly, searching for pre-industrial extra-terrestrial societies may be more productive. Using the earth as a model, a consideration of possible detectible proxies suggests that observation of seasonal agriculture may be possible in the near future – particularly in ideal circumstances, for which quantitative analysis is provided. More speculatively, other detectible processes may include: species introduction; climate change; large urban fires and land-use or aquatic changes. Primitive societies may be both aware that their activities may be observed from other planets, and may deliberately adjust these activities to aid or conceal detection.

scholarly journals The flyby anomaly and the gravitational–magnetic field induced frame-dragging effect around the Earth

2019 ◽  
Vol 489 (3) ◽  
pp. 3232-3235 ◽  
Author(s):  
Babur M Mirza
Keyword(s):  
Magnetic Field ◽  
Theoretical Analysis ◽  
Energy Difference ◽  
Observational Error ◽  
Frame Dragging ◽  
Null Results ◽  
The Earth ◽  
Linear Distance ◽  
General Relativistic ◽  
Distance Relation

ABSTRACT The anomalous energy difference observed during the Earth flybys is modelled here as a dynamical effect resulting from the coupling of the gravitational and the magnetic fields of the Earth. The theoretical analysis shows that general relativistic frame-dragging can become modified under the Earth’s magnetic field by orders of magnitude. For 12 flyby cases, including the null results reported in some recent flybys, the predicted velocities correspond to the observed velocities within the observational error. The gravitomagnetic effect is also shown to account for the linear distance relation, time-variation of the anomalous energy, and the reduction in the anomalous velocity for high-altitude flybys near the Earth.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

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