Electromagnetic field radiation

Noting that in the absence of strong electromagnetic fields radiation beams travel in straight paths, the view factor from a surface to ilse.lf is zero unless the surface sees" itself. Therefore, 0 for plane or convex surfaces and F/, ( A Oforconcave surfaces, as illustrated in Fig. 13-3. 

Table 1 Frequency spectrum of the electromagnetic field radiation in the frequency range of 0-10 ° Hz. It includes some examples of broadly used applications and also shows the separation between nonionizing and ionizing radiation as a function of the frequency range...

Modern microbalances, especially the magnetic suspension balances are fairly complex systems which often are sensitive to electromagnetic or - to lesser extend - mechanical disturbances from outside. Oscillations of the basement caused by nearby subways or trucks may cause disturbances, though balances recently (2002) have become less sensitive to these. However, electromagnetic fields radiating from electric heating systems or other wires inside a lab can lead to serious problems in the performance of either the balance itself or the data recording system. 

Study of Electromagnetic Field Radiation on the Human Muscle Activity... 

Electromagnetic field radiation generally comes from the natural and man-made sources. The natural electromagnetic... 

The measurement is concentrated to the strength of electromagnetic field radiation from the fluorescent lights and computer screen. EMDEX Snap is used in to capture the strength of electromagnetic field radiation of the fluorescent light and computer screen. 

Five trials, which involved typing performance, involved exposure to the electromagnetic field radiation at five different levels. These five cases of exposure are as follows CASE 1 Without any radiation - control group CASE 2 Expose to 1 LCD screen CASE 3 Expose to 1 LCD screen and 4 fluorescent light CASE 4 Expose 1 CRT screen... 

The measurement was made for five different exposure cases where each case represented a different situation. The magnitude of the electromagnetic field radiation for the five different exposure cases during the experiment is summarized in Table 1. 

In order to investigate deeply as to which cases are significantly different from the control group, the Post-hoc testing was performed using Tukey s method with a = 0.05. The multiple comparisons of Case 1 to the other cases (Case 2 to Case 5) were carried out. The Post-hoc result is summarized in Table 2. The P-values are recorded to be less than 0.05 for all muscles. It was proven statistically that muscle activity had increased when the strength of the electromagnetic field radiation was increased. 

The EMG data (which was taken to represent the activeness of the muscles) was examined throughout the typing task to identify any pattern of change during the 20 minute s experimental period of the five exposure cases. Case 1 represents the control group, where the condition involved no electromagnetic field radiation. The level of electromagnetic field radiation was increased from Case 2 to Case 5. 

Furthermore, the extensor muscles are shown to be more active compared to the flexor muscles in RMS of EMG by 52.6 % when exposed to the radiation. The muscle activity is observed to be more acutely affected when the electromagnetic field radiation is increased. 

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