Recent content by lost_in_space

hello, i found a patent in the internet where a device is presented in which a body is surrounded by water (especially if you scroll down on the 12th and 13th page in the document). www.google.com/patents/US7353554.pdf the author claims that the body is floating inside the device...

Thank you for your kind answer. it will take me some time to study the literature. best wishes lost_in_space

thank you for the answer, the links did help and clearify a bit. however, my big problem is not the steering (there is a huge amount of mathematical methods to do that). The thing i don't know is how to realize a physical implementation. which hardware do i need. how high are the costs for...

hello, i am involved in a private project. for this project it is necessary to control a huge amount of loudspeakers (intensity, frequency) in order to achieve beam forming of the sound waves. However, since i am not an electrical engeneer i really do not have a clue how something like this...

this is just a naive question from a person who is not a physican, imagine that charged particles ( ions ) could only move in a plane. if a homogeneous magnetic field perpendicular is imposed what would happen ? i think that the particles must come to rest since they emitt electromagnetic...

hello, since a while my mind is caught by an idea. This idea is concerned with underwater sound massage system. For this purpose i would like to build an array of underwater sound transducers, which can all be steered individually (to do a coarse beam forming). However, since i am...

yes, but is the beam then simply supported ? thx.

Thank you very much. Just to be shure that i got it right: If a beam (say from x = 0 to x=L) is placed layed on two rolls (located at x= 0 and x= L) and i have transverse load. If w denotes the deflection of the beam i have to impose the boundary conditions w(0) = w(L) = 0 (are there...

hello, I have got a question concerning statics. is a beam that is layed onto two rolls (of equal size) simply supported ? I would be glad if anyone could answer this question.

thank you very much for the detailed answesr. my question otginates from the field of medical imaging. To be more precise in MRI nuclei are excited (placed in static magnet field and then are influenced by another EM pulse) so that they will emit a radio frequency wave... this wave propagates...

my question concerns electromagnetic (EM) wave propagation. consider a two layer medium where the first layer has constant conductivity $\sigma_0$ and the second layer constant conductivity $\sigma_1$. If a EM wave propagates from the first medium into the second one boundary conditions have...

Hello people, i have got a few thoughts which i would like to share. I few month ago i foundout that there are laser beams in the frequency range of of microwaves (maser beams). (http://en.wikipedia.org/wiki/Maser) I consider the following situation: If a conducting medium (lets think...

thank you, the last example you gave is very nice. certainly, two points that are closer than then the diameter of the spot size of the beam cannot be distinguished by it... one more question: does this near field contein thes "evanescent waves" which are damped exponentially ?

hello sophie, thank you for the answer. what is measured in Computed tomography the intensity loss of a beam after it has crossed the body. Then it is assumed that this value is proportional to the line intagral of a density function... and after all the answers to my question i have...

Thank you again I know that the resolution limit is bounded by the wavelength in optics. However, i didt not understand how this argument applies to computed tomography. For example: as an xray beam propagates through the body its intensity loss is determined by the density of the...