“Ask the Experts" is moderated by Béla Lipták, process control consultant and editor of the Instrument Engineer's Handbook (IEH). He is recruiting a team of co-authors to work on the 5th edition and welcomes contribution offers from qualified colleagues. If you have questions for our team of experts, please send them to: email@example.com.
Q: My measurement question has to do with archeology. King Attila died in 453 CE and according to legend, was buried in three metallic caskets, one inside the other (made of gold, silver and copper). Also according to legend, a river was rerouted over the grave to protect it from being robbed. This grave is likely to contain valuable information concerning the 5th century and the Hun culture. Are there metal sensors that could scan a riverbed to find these caskets?
A: Put on a diver suit and walk the river bed. If you can find a group of archeology students who are willing to spend their summer vacation walking the riverbed, using equipment such as a high-end metal detector, you could try doing it. Naturally, you would need sponsors to cover the expenses of renting tents, diver suits, metal detectors, etc. The principles of detection are covered in my handbook, and suppliers are listed at http://tinyurl.com/35bhfqy and www.hotektech.com/Tinsley5916.htm
A: Detecting gravitational anomalies might be the only way to do it. The question is will the size of the burial be large enough to create an anomaly large enough to be seen through the water. The paper referenced below is a good introduction to the measurement and detection of gravitational anomalies and refers to oilfield practices too.
The author of the question is certainly correct. The finding of the burial of Attila would be an archaeological coup of major proportions, second only to the discovery of the tomb of Temujin, a.k.a. Genghis Khan (1162?–1227?). And Attila should finally get some good press. He appears to have been a rather sophisticated Roman-educated leader—not a filthy barbarian, as he is often portrayed.
Start your search here: www.au.af.mil/au/awc/awcgate/awc/streland.pdf.
A: Fluid Kinetics used to sell a device which was used to detect the presence of communication cables in the ocean. I do not know if this device is still on the market, but it might be able to help find these legendary caskets. [Editor's note: This product line has been acquired by Subsea Systems of Ventura, Calif., www.subsea-usa.com.]
Steve Freitas, CCI
Q: You wrote about the potentials of process control in modeling and predicting the performance of non-industrial processes such as the economy. Could the laws of process control be also used to estimate the rate and consequences of global warming?
A: I did discuss some aspects of global warming when I wrote about the process dynamics of the Gulf Current (www.controlglobal.com/articles/2006/002.html) and also wrote a book titled The Post-Oil Energy Technology, (http://tinyurl.com/38o2yy7), which also included a discussion of the rates and time constants of global warming.
One can look at this process as one which started about 2 billion years ago when the atmosphere began to change from a reducing (CO2) to an oxidizing one (O2). This is the time when climate evolution started and life appeared on the planet. The atmospheric concentration of O2 stabilized at around 21% and its CO2 content never increased over 280 ppm during the last couple of million years, but during the industrial age greenhouse gases were admitted into the atmosphere, causing the CO2 content to rise to 360 ppm to 380 ppm, and this concentration is projected to reach 510 ppm by the turn of the 21st century (Figure 1).
It seems that life depends on the presence of liquid water (which can exist only between 0˚C and 100˚C) and on an atmosphere that protects life from both ultraviolet radiation and extreme temperatures. Weather is the state of the atmosphere that results from a number of processes. One of these processes is the heat balance of the planet.
Global temperature is a somewhat self-regulating process because, as the heat input of the planet increases, the excess heat is removed by increased vaporization of the oceans and increased melting of the polar ice caps and glaciers. Melting and vaporization both increase the overall water circulation on the planet (storms, rain, floods), while increased vaporization also dries land areas, increasing the frequency of forest fires, water shortages and desertification.
While the melting of the ice requires heat, and therefore temporarily cools the planet, it has the reverse effect in the long run, because ice and snow reflect more radiation back to space than does water. The reflection coefficient, the Bond albedo, says 29% of solar radiation received is scattered back into space, but as ice melts, that number drops.