Recent content by pierebean

The physics is just to illustrate the use of the formula. But I would like to prove mathematically the one-to-one relationship between the two minimums. Maybe physicists knows the answer to this calculus question but it's still calculus now? If not, in what section of physics should I put this...

Hello, To measure the atomic force with an AFM. One can use the frequency shift of a cantilever. This change of frequency is linked to the atomic force by what we called the Franz J. Giessibl formula in the community. z is the AFM tip-sample distance. frequency(z) is the change of...

Thank you for pointing this out. Indeed, many phenomena in physics are usually not discrete (currently I'm only thinking of phase transition which almost is). However, if this auto ionization phenomenon is described by a exponential, one might define a semi-threshold (actually an order of...

Hello fellow physics lovers, I wish to predict the behaviour of a organic molecule under an electric field (High Voltage). I wish to know how much E-field can this molecules withstand before being fragmented. Can anyone point toward a freeware than might compute such a field? It is...

Thank you Bobbywhy for your prompt response, At the moment the apparatus is at an early stage. Before continuing further, I just want to how if it was feasible and preferential commercially available or even better "cheaply makeable". I have a vacuum chamber with an electron source. On the...

Hello, I wish to switch ON and OFF a high-voltage (that generates a high electric field) using a ultra-fast laser as a trigger. Basically I have a flow of charged particles that I want to quickly deflect using an E-field. The timing must be correct and controlled by a LASER. Does anyone...

Hello, I am no mechanical engineer and my knowledge in bending is limited to Euler-Bernouilli beam theory. I wish to analytically calculate the normal stress of a plate bent by four points bending. I have already calculated this stress for a beam. However I cannot apply the beam theory...

Any leads maybe?

I forgot to mention that my resistivity was a tensor and not a mere scalar.

Bonjour, I need to numerically compute the net electrical resistance of a given geometry. I know the shape of my object, it is relatively simple. It's close to this: http://2.imimg.com/data2/QX/UC/IMFCP-3019296/i-shape-big-1-250x250.jpg Actually my shape is even simpler because it's a...