SOME PHYSICAL PROPERTIES AND BIOLOGICAL EFFECTS OF THE RADIATIONS OF THE ELECTROMAGNETIC SPECTRUM

1934 ◽  
Vol 11 (3) ◽  
pp. 79-108
Author(s):  
Charles Sheard
Author(s):  
Geoff Cottrell

In the eye, detection is done by the retina. In telescopes operating in different parts of the electromagnetic spectrum, light interacts with matter in different ways, and so a variety of detectors is used. ‘Instruments of light’ describes how, first, photographic, and then electronic light detectors have greatly increased the sensitivity of telescopes, and made it possible to record the state of the sky, as well as obtain information on the physical properties of stars and galaxies. It describes photometry, the quantum efficiency of light detectors, charge-coupled devices, and high-energy proton detectors, and explains the processes of diffraction grating and spectroscopy. Telescopes and their detectors are now inseparable.


2014 ◽  
Vol 44 (1) ◽  
pp. 237-248 ◽  
Author(s):  
Lorena Torres-Ronda ◽  
Xavi Schelling i del Alcázar

Abstract The biological effects of immersion in water, which are related to the fundamental principles of hydrodynamics, may be beneficial in certain training contexts. The effects and physical properties of water, such as density, hydrostatic pressure and buoyancy are highly useful resources for training, when used as a counterbalance to gravity, resistance, a compressor and a thermal conductor. Not only does the aquatic medium enable a wider range of activities to be used in a context of low joint impact, but it also constitutes a useful tool in relation to sports rehabilitation, since it allows the athlete to return to training earlier or to continue with high-intensity exercise while ensuring both low joint impact and greater comfort for the individual concerned. Moreover, this medium enables the stimulation of metabolic and neuromuscular systems, followed by their corresponding physiological adaptations allowing both to maintain and improve athletic performance. Hydrotherapy can also play a beneficial role in an athlete’s recovery, helping to prevent as well as treat muscle damage and soreness following exercise.


Author(s):  
Colin J Martin

The opening chapter introduces the use of radiation in medicine. It lists the main events in the application of radiation following the discovery of X-rays in 1895, the beginning of the use of radioactive sources in therapy in the early 1900s, the development of nuclear medicine in the 1960s, and the first computed tomography scanner in 1972. Radiation protection began to develop as a specialty at an early stage, but it was following analysis of effects on the survivors of the atomic bombs dropped on Japan that the need for stricter control became apparent. The chapter also reviews the development of standards for non-ionizing radiations. Summaries of medical applications for all parts of the electromagnetic spectrum are included, and the main biological effects of different types of radiation are included.


2017 ◽  
Vol 25 (6) ◽  
pp. 680-688 ◽  
Author(s):  
Bin-Na Lee ◽  
Soo-Ji Chun ◽  
Hoon-Sang Chang ◽  
Yun-Chan Hwang ◽  
In-Nam Hwang ◽  
...  

2012 ◽  
Vol 1 (4) ◽  
Author(s):  
Fatma Vatansever ◽  
Michael R. Hamblin

AbstractFar infrared (FIR) radiation (λ=3–100 μm) is a subdivision of the electromagnetic spectrum that has been investigated for biological effects. The goal of this review is to cover the use of a further sub-division (3–12 μm) of this waveband, that has been observed in both


Daedalus ◽  
2014 ◽  
Vol 143 (4) ◽  
pp. 93-102 ◽  
Author(s):  
Michael A. Strauss

Astronomers can map the sky in many ways: observing in different regions of the electromagnetic spectrum, obtaining spectra of stars and galaxies to determine their physical properties and distances, and repeatedly observing to measure the variability, explosions, and motions of celestial objects. In this review I describe recent surveys of the sky astronomers have carried out, focusing on those in the visible part of the spectrum. I describe in detail the Sloan Digital Sky Survey, an ongoing imaging and spectroscopic survey of over one quarter of the celestial sphere. I also discuss some of the major surveys planned for the next decade, using telescopes both on the ground and in space.


Public exposure to Electromagnetic Radiation, which abbreviatedly known as EMR is a recurring phenomenon and it becomes among the factors contributing to the public concerns. EMR represents a new technology, such as base stations, overhead power lines and other sources of exposure, that is difficult to control by the affected individual. Non-ionizing and ionizing radiation are two major divisions of the electromagnetic spectrum. Both kinds of radiation can be differentiated based on which one has enough energy to knock electrons off atoms upon collision, as well as capable to give out lower-energy harm, such as breaking chemical bonds in molecules. Ionizing radiation is a type of radiation that has a short wavelength to interact with the electrons in biological chemicals. Alpha, beta, and gamma rays are examples of ionizing radiation. The literature on RF effects also focused on the human factor and health parameters, both from the laboratory and epidemiological study perspectives. The presence of this communication technology has given rise to media and public concerns about the possibility of RF radiation emitted by computers, phones and base stations that might cause a rise in diseases that affect the reproductive system, neurobehavioral parameters and various forms of cancers, especially brain tumours. More recently, concerns about the possible effects culminating from the massive development of base stations coupled with increasing use of mobile phones have begun to appear due to the enormous growth of wireless mobile communication, mainly handheld devices. This has led to increased apprehension as to whether non-ionizing radiation (NIR) used in present technologies could have short, medium and long-term biological effects.


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