Radio and Telecommunications

Lightspeed ◽  
2019 ◽  
pp. 159-179
Author(s):  
John C. H. Spence
Keyword(s):  
Experimental Work ◽  
Global Network ◽  
Space Probe ◽  
Speed Of Light ◽  
Radio Communication ◽  
Space Communications ◽  
Heinrich Hertz ◽  
Electro Magnetic ◽  
Set Up ◽  
Communications System

The Cassini space probe and its recent voyage to Saturn, and communications system are described. Communication with it at the speed of light takes over an hour to reach Earth. The power and range of its transmitter, how its antenna works, and NASA’s deep space communications global network. Heinrich Hertz and the discovery of radio communication in 1887, after Maxwell’s death. FitzGerald’s publication predicting radio transmission in 1883. His life and apprenticeship under Helmholtz and theoretical and experimental work. His use of a spark gap as a receiver with resonant circuits to set up standing electro-magnetic waves in his laboratory. His discovery that these waves, of much lower frequency than light, travelled at the speed of light. Dipole radiation. Hertz’s visit to London and his life. David Hughes, his life, adventures and inventions, including the carbon microphone and printing telegraph, and his accidental pre-discovery of radio using a carbon microphone as a “coherer” detector.

Introduction

Popular Music ◽  
2007 ◽  
Vol 26 (1) ◽  
pp. 1-4
Author(s):  
David Horn
Keyword(s):  
African American ◽  
Popular Music ◽  
International Association ◽  
Outstanding Contribution ◽  
Global Network ◽  
Founding Member ◽  
Vernacular Music ◽  
The World ◽  
Set Up

This issue of Popular Music is produced in honour of Paul Oliver, in recognition of his outstanding contribution to popular music scholarship.Paul was a member of the original Editorial Board for Popular Music when it was set up in 1980 and continued to serve as a member of that body, and subsequently of the Editorial Group, until 1990. He was also a founding member of the International Association for the Study of Popular Music and has maintained a keen interest in the organisation, continuing to attend, and speak at, its international conferences. His vision of both the potential and the needs of the Association as a global network lay behind his proposal in 1985 that a project be undertaken to compile a worldwide encyclopedia of popular music, an idea which subsequently bore fruit in EPMOW (The Encyclopedia of Popular Music of the World). All these achievements are worth celebrating in themselves, but it is Paul's outstanding contribution to scholarship in the area of vernacular – particularly African-American vernacular – music that we wish to honour with this issue.

Universal Software Radio Peripheral/GNU Radio-Based Implementation of a Software-Defined Radio Communication System

2019 ◽  
pp. 227-240
Author(s):  
Ehsan Sheybani
Keyword(s):  
Communication System ◽  
Software Defined Radio ◽  
Software Radio ◽  
Block Code ◽  
Radio Station ◽  
Frequency Change ◽  
Gnu Radio ◽  
Radio Communication ◽  
Space Communications ◽  
Radio Communication System

Challenges involved in space communications across wireless channels call for new approaches to radio systems. Due to the growing need for frequency change in modern wireless systems, an adaptive radio system has the highest demand. Software-defined radios (SDR) offer this type of adaptivity as well as compatibility with other standard platforms such as USRP/GNU radio. Despite limitations of this approach due to hardware components, viable modeling and simulation as well as deployable systems are possible using this platform. This chapter presents a detailed implementation procedure for a USRP/GNU radio-based SDR communication system that can be used for practical experiments as well as an academic lab in this field. In this experiment the USRP has been configured to receive signal from a local radio station using the BasicRX model daughterboard. The programmable USRP executes Python block code implemented in the GNU Radio Companion (GRC) on Ubuntu OS.

Development of Thermal Spray Map for Liquid Feeding Thermal Spray System

2017 ◽  
Vol 866 ◽  
pp. 418-421
Author(s):  
Noppakun Sanpo ◽  
Jirasak Tharajak
Keyword(s):  
Data Mining ◽  
Particle Size ◽  
Thermal Spray ◽  
Experimental Work ◽  
Research Work ◽  
Reference Points ◽  
Range Data ◽  
Spray System ◽  
Liquid Feeding ◽  
Set Up

This research work exhibits a procedure to classify and reorder thermal spray data point so that relationships and correlations between competing processes and materials can be identified. The broad range data mining of published experimental work was performed to create thermal spray map (TS map). A single TS map displayed the correlation between standoff distance (SOD) and feeding particle size is mainly focused. The discussion and evaluation of TS map was taken place. These data mining could be useful to use and/or adapt as reference points for the thermal spray experiment set up in the future.

scholarly journals Experimental Investigations of Noise Control in Planetary Gear Set by Phasing

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
S. H. Gawande ◽  
S. N. Shaikh
Keyword(s):  
Experimental Work ◽  
Noise Level ◽  
Planetary Gear ◽  
Experimental Investigations ◽  
Mesh Stiffness ◽  
Gear Noise ◽  
Gear Drive ◽  
Internal Excitation ◽  
Key Factor ◽  
Set Up

Now a days reduction of gear noise and resulting vibrations has received much attention of the researchers. The internal excitation caused by the variation in tooth mesh stiffness is a key factor in causing vibration. Therefore to reduce gear noise and vibrations several techniques have been proposed in recent years. In this research the experimental work is carried out to study the effect of planet phasing on noise and subsequent resulting vibrations of Nylon-6 planetary gear drive. For this purpose experimental set-up was built and trials were conducted for two different arrangements (i.e., with phasing and without phasing) and it is observed that the noise level and resulting vibrations were reduced by planet phasing arrangement. So from the experimental results it is observed that by applying the meshing phase difference one can reduce planetary gear set noise and vibrations.

Identification of independent modes in two inputs free space communications system

2021 ◽  
Vol 136 ◽  
pp. 106320
Author(s):  
Eugen Scarlat ◽  
Mona Mihăilescu ◽  
Irina Alexandra Păun
Keyword(s):  
Free Space ◽  
Space Communications ◽  
Communications System

VCM-OFDM technique for advanced space communications system with high spectral efficiency

2016 ◽  
Vol 128 ◽  
pp. 385-391 ◽  
Author(s):  
Jionghui Li ◽  
Qing Zhou ◽  
Weiming Xiong ◽  
Ying Zhang ◽  
Chen Yao
Keyword(s):  
Spectral Efficiency ◽  
Space Communications ◽  
High Spectral Efficiency ◽  
Communications System

scholarly journals Studies on the flexor reflex.-V. General conclusions

1931 ◽  
Vol 107 (754) ◽  
pp. 597-605 ◽  
Keyword(s):  
Spinal Cord ◽  
Experimental Evidence ◽  
Experimental Work ◽  
Reflex Activity ◽  
Flexor Reflex ◽  
Afferent Nerves ◽  
The Subject ◽  
Set Up ◽  
Afferent Terminals ◽  
Antidromic Volley

The experiments described in the preceding four papers bear on various problems presented by reflex activity. Their results confirm some of the inferences already drawn elsewhere from other experimental work, and they allow certain further inferences. A brief prefatory statement of all these inferences and of the experimental evidence which allows them will advantageously introduce the description of the processes set up in the ipselateral flexor centres of the spinal cord by a single centripetal volley and by a single antidromic volley. Then, finally, discussion of the theories of reflex excitation can be undertaken in the light of the present experimental observations. the statement treats of the subject in its present phase only; the references to relevant papers are therefore restricted in the main to the more recent ones. II. Inferences from Experimental Observations. 1. The convergence of Different Afferent Paths on the same Motoneurones The following evidence shows that this occurs:- (a) Histological .-Each motoneurone receives its “ boutons terminaux ” from many individual afferent terminals (Cajal, 1903). (b) Physiological .-Centripetal volleys set up in different afferent nerves excite the same motoneurones (Camis, 1909; Cooper, Denny-Brown, and Sherrington, 1926; 1927; Sherrington, 1929; Cooper and Denny-Brown, 1929 ; Eccles and Sherrington, 1930 ; 1931, a ; 1931, b ).

Hertz, Heinrich Rudolf (1857–94)

2018 ◽  
Author(s):  
Peter Barker
Keyword(s):  
Uniform Motion ◽  
Radio Waves ◽  
Radio Communication ◽  
Long Distance ◽  
Free System ◽  
Maxwell’S System ◽  
Heinrich Hertz ◽  
Action At A Distance ◽  
State Of Rest ◽  
New Formulation

Heinrich Hertz demonstrated the existence of radio waves in research between 1887 and 1888, opening the way for Marconi to develop long-distance radio communication. Hertz’s results confirmed Maxwell’s electromagnetic theory, and sealed the fate of action-at-a-distance in physics. His theoretical analysis included the famous dictum: ‘Maxwell’s theory is Maxwell’s system of equations’. Hertz also developed a new formulation of Newtonian mechanics using the concepts of mass, length and time, but not force. He presented mechanics as the axiomatic consequence of a single fundamental law: ‘every free system persists in its state of rest or of uniform motion in a straightest path’. Hertz’s ideas influenced later philosophers of science but were most important as a source for Wittgenstein’s Tractatus Logico-Philosophicus, which influenced logical positivism. Hertz’s proposal to eliminate the concept of force in physics was an important contribution to the twentieth-century ideal of a philosophical method that does not solve, but rather dissolves, philosophical problems.

Application of Tapered Monocapillary in a Laboratory Mxrf Set-Up

1995 ◽  
Vol 39 ◽  
pp. 81-86
Author(s):  
N. Gao ◽  
I. Ponomarev ◽  
Q. F. Xiao ◽  
W. M. Gibson ◽  
D. A. Carpenter
Keyword(s):  
Experimental Work ◽  
High Energy ◽  
X Rays ◽  
Output Beam ◽  
Bremsstrahlung Radiation ◽  
X Ray ◽  
Set Up

Simulation and experimental work that compare the performance of straight and tapered monocapillaries when used with laboratory x-ray sources are reported. Detailed simulations for various taper profiles give several important conclusions for optimizing the design of a tapered monocapillary. Several tapered monocapillaries were prepared. With a 16W x-ray source, beam intensities of 4×105 photon/sec/μm2 and 3×105photon/sec/μm2 of Cu Kα x rays were obtained from the tapered monocapillaries for output diameters of 8μm and 3.5μm, respectively. These intensities are 1.4 and 1.5 times that obtained from straight capillaries with the same output beam sizes at the experimental set-up optimized for a straight capillary. In addition to the gain in x-ray flux, the tapered monocapillaries produce output beams with significantly reduced high energy bremsstrahlung radiation and increased flux stability with respect to shifts of the x-ray source spot.

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