Electromagnetic Waves and Heat Transfer: Sensitivities to Governing Variables in Everyday Life

2021 ◽  
Author(s):  
M. Kemal Atesmen
Keyword(s):  
Heat Transfer ◽  
Everyday Life ◽  
Electromagnetic Waves

Theory of heat transfer by evanescent electromagnetic waves

1994 ◽  
Vol 50 (24) ◽  
pp. 18517-18524 ◽  
Author(s):  
Jackson J. Loomis ◽  
Humphrey J. Maris
Keyword(s):  
Heat Transfer ◽  
Electromagnetic Waves

High-temperature Fiber Matrix Composites for Reduction of Radiation Heat Transfer

2009 ◽  
Vol 1162 ◽  
Author(s):  
Valery Shklover ◽  
Leonid Braginsky ◽  
Matthew Mishrikey ◽  
Christian Hafner
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Electromagnetic Waves ◽  
Photonic Band Gap ◽  
Radiation Heat Transfer ◽  
Expansion Method ◽  
Woven Fabrics ◽  
Matrix Composites ◽  
Fiber Matrix ◽  
Monolithic Ceramics

AbstractRecent progress in fabrication technology allows for the efficient control of electromagnetic waves by means of photonic devices. This could be attractive and promising also for high-temperature photonic structures to control electromagnetic heat transfer at temperatures above 1000 oC. We discuss the literature and present our own results on Fiber Matrix Composites (FMC), which could be superior to high-temperature metals or monolithic ceramics and can be designed for photonic applications. Possible applications include the protection of non-rotating components in high-temperature engines and turbines such as combustors and liners, coatings and parts for aerospace vehicles. Our discussion includes the material aspect and some relevant structure features. The use of woven fabrics to design new photonic band gap structures is discussed. An example of the use of the plane-wave expansion method for FMC design is given.

scholarly journals Effects of Rainfall Attenuation on Frequencies 1 and 3 GHZ in Nigeria

2016 ◽  
Vol 15 (5) ◽  
pp. 6711-6723
Author(s):  
Ogherohwo, E. P ◽  
Bukar, B ◽  
Baba, D. D.
Keyword(s):  
Frequency Dependence ◽  
Everyday Life ◽  
Frequency Spectrum ◽  
Spectral Range ◽  
Mobile Communications ◽  
Electromagnetic Waves ◽  
Rain Rate ◽  
Rainfall Data ◽  
Radio Communication ◽  
Rainfall Attenuation

Mobile communications are part of our everyday life. The non-ideal environment which is filled with many attenuation factors affects the electromagnetic waves, which radio communication depends. This study considers the spectral range of 1 and 3GHz. At these frequencies, interesting phenomena due to rain are supposed to happen. The study of this frequency spectrum has been undertaken in an attempt to evaluate the frequency dependence of rain effects on electromagnetic waves. The study of rain effects on communication presented in this study relied solely on rainfall data collected from Nigeria Metrological Agency (NiMet) station in Lagos, Nigeria. The months for January to December for 1981-2011 were summed together and the averages were determined. The average is then used to calculate the rain rate and rainfall attenuation using the extracted results for all the locations (Bauchi, Ikeja, Jos, Kebbi, Maiduguri and Warri). The results show that Warri has the highest rainfall rate followed by Lagos. Kebbi and Maiduguri has the least while Jos and Bauchi demonstrated moderate rainfall rates. This also deduced that attenuation has less impact on lower frequencies but increase with higher frequencies. The study reveals that at higher frequencies, the rainfall attenuation is observed to be greater.

Harvesting Nanoscale Radiation Heat Transfer With Pyroelectric Materials

2009 ◽  
Author(s):  
Jin Fang ◽  
Hugo Frederich ◽  
Laurent Pilon
Keyword(s):  
Heat Transfer ◽  
Energy Transfer ◽  
Energy Conversion ◽  
Electromagnetic Waves ◽  
Waste Heat ◽  
Radiation Heat Transfer ◽  
Low Frequency ◽  
Working Fluid ◽  
Radiation Heat ◽  
New Device

Pyroelectric energy conversion offers a novel, direct energy-conversion technology by transforming time-dependent temperature directly into electricity. It makes use of the pyroelectric effect to create a flow of charge to or from the surface of a material as a result of heating or cooling. However, existing pyroelectric energy converter can only operate at low frequency due to relatively low heat transfer rate between the pyroelectric materials and the working fluid subjected to oscillatory fluid flow between hot and cold sources. On the other hand, energy transfer by thermal radiation between two semi-infinite solids can be enhanced by several orders of magnitude as the gap separating them reduces to subwavelength size thanks to interference and tunneling of electromagnetic waves across the gap. This paper proposes a novel way to harvest nanoscale radiation heat transfer for direct pyroelectric energy conversion of waste heat into electricity. A new device is investigated numerically by accurately modeling nanoscale radiation heat transfer between the pyroelectric materials and hot and cold surfaces. Performance of the pyroelectric converter is predicted at various frequencies. The result shows that rapid energy transfer and higher operating frequency can be achieved to increase efficiency and power density.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

Microwaves: Application in Electron Microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 140-141
Author(s):  
Anthony S-Y Leong ◽  
David W Gove
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Chemical Reactions ◽  
Electromagnetic Waves ◽  
Tissue Fixation ◽  
Primary Method ◽  
Dipolar Molecules ◽  
Wide Range ◽  
Time Required ◽  
Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

Thriving in Academia: Understanding and Managing the Complexities of Faculty Work

2012 ◽  
Vol 15 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Ketevan Mamiseishvili
Keyword(s):  
Higher Education ◽  
Education Research ◽  
Community Engagement ◽  
Everyday Life ◽  
Work Setting ◽  
Higher Education Research ◽  
Faculty Work ◽  
College And University ◽  
Teaching Research ◽  
University Settings

In this paper, I will illustrate the changing nature and complexity of faculty employment in college and university settings. I will use existing higher education research to describe changes in faculty demographics, the escalating demands placed on faculty in the work setting, and challenges that confront professors seeking tenure or administrative advancement. Boyer’s (1990) framework for bringing traditionally marginalized and neglected functions of teaching, service, and community engagement into scholarship is examined as a model for balancing not only teaching, research, and service, but also work with everyday life.

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