1. Lecture 3 Assignment
1. In addition to reading through Chapter 1 , read one paper on the exposures that you get from a low frequency source and write up a one page summary. Also you should start looking for papers on a topic you want to follow up on and write a one page summary of it.
2. This is due next Monday

2. Bioelectromagnetics ECEN 5341/4341 Lecture 3-4
1. Environmental and Occupationally Encountered Electromagnetic Fields
2. The objective is to get a feel for the size of both the natural fields we are exposed to and the size of the fields that we are now exposed to resulting from the wide spread use of electricity.

3. Atmospheric Sources 1. Static and ELF (0 to 3khz)
2. Earth’s Static Magnetic Fields range from 24μT to 65μT with variation up to about 1μT with the Northern Lights over several minutes
3. Electric fields Static 100 to 300V/m with the earth negative. Up to 100kV/m in thunderstorms.

4. Natural EM Power Density at the Earths Surface

5. B Field for Underwater Cable
Normal load 400A shielded so no E field outside

6. High Voltage AC Lines
Standards in US limit Fields to 1 to 5kV/m

7. Magnetic fields from Power Lines as a Function of Distance

8. The Effects of Power Pole Configurations and Phasing on Magnetic Fields

9. 1

10. Some Typical Magnetic and Electric Field Strengths vs. Distance

11. Fourier Spectrum of A Current Wave Form

12. Typical Magnetic Field Exposure Levels At Home

13. 1

14. Variations with time of Day

15. Variations in Magnetic Field Exposures Over the Course of a Day

16. Some Current Wave Forms

17. The Fourier Spectra of 1.7

18. Lecture 4 January 25, 2017 Two Reference Formats.
Brocklehurst B, McLauchlan K Free radical mechanism for the effects of environmental electromagnetic fields on biological systems. Int J Radiat Biol 69:3–24.
[28] K. Wang and T. Ritz, “Zeeman resonances for radical-pair reactions in weak static magnetic fields,” Mol. Phys., vol. 104, no. 10–11, pp. 1649–1658, 2006.

19. Magnetic Fields Around Appliances

20. 1

21. Wave Shapes Near Fluorescent Light

22. Common Exposures

23. Exposures on Electric Trains

24. Electric Field Scaling and Induced Currents

25. Induced Electric Fields

26. A More Complete Model

27. 1

28. Electric and Magnetic Induced Current Densities

29. Internally Generated Voltages

30. 1

31. Lecture 5
January 27,2017

32. Sources of Intermediate and Radio Frequency Fields
1. Scanners , Libraries, Airport Security
920MHz , B = 10µT and Deactivate at 50-60Hz 500µT
2. Video Display Terminals, VDT, Cathode Ray Tubes CRT Up to 20KV inside the Tube, ≈10V/m at 0.5m

33. Computer Display Fields1

34. RF Sources 2. RF heaters for sealing plastic etc.
3. RF Transmission Short Wave MHz 3-20V/m at 10’s of meters.
4. Radio TV
5. Base Stations and Cell Phones, WiFi

35. TV and Base Stations

36. Exposure Levels 1. US average about 50µW/m2 to 100µW/m2
2. We have measure E =1 to 2 V/m in Boulder, peak power density < 10 mW/m2
3. Peak Power from transmitter about50 KW
4. Radar Peak at Megawatts, over the horizon

37. Frequencies