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  1. Clausius2

    What's the story!

    Hi everybody (to those who remember me). Hope all is well with you. I'm now in the bay area, in a city called "High Stick" in spanish and work in an office very close to the MemChu. :)
  2. Clausius2

    Hiked in Yellowstone, Zion, Bryce, Capitol Reef

    Just wanted to let you know, to those PF veterans that may remember me from writing here a long time ago, that, four years and a half after, I'm finally done with my phd and with my adventures in usa (for the moment)! I'll go back to europe after this (to france). I also wanted to add that...
  3. Clausius2

    Abel's formula

    When dealing with Abel's formula for the wronskian of a second order ODE: W(R)=Ce^{-\int p_1(R)dR} and assuming that you don't know the homogeneous solutions but you know their asymptotic behavior at infinity and at the origin, how is the constant C calculated? Thanks.
  4. Clausius2

    Air in slow viscous motion

    The other day I met a mathematician and I told him I was considering air as the surrounding fluid for the slow viscous flow around a body. And he replied: "what?. This is viscous motion, so you cannot consider air.", implying that I should use water instead. Who of us do you think was...
  5. Clausius2

    Buran Vehicle (USSR)

    I was nostalgic of the 80's and the cold war and I came up with this while surfing the web: The Buran's program. It's incredible how much bad luck did they have. Eventually an hangar collapsed down and killed 8 workers and one of the built...
  6. Clausius2

    Science Revisited

    I'm a grad student, probably in the top5 list of departments in the whole world that best address the discipline of my research, and here is my opinion after 1 year and 3 months of experience. My impression about nowadays science is that it is polluted. The good news are that still it is not...
  7. Clausius2

    Asymptotic expansion integral

    Hey guys, I need help with the expansion of this integral: \int_0^\infty Z(x) J_o(\lambda x)dx for \lambda \rightarrow \infty where I know that Z(x)\sim x^\sqrt{2} for small x and exponentially small for large x It seems with other examples that I have done that the major...
  8. Clausius2

    Disabling car alarm

    Okay, maybe this is not such a technical question, but does anybody know how to disconnect a car alarm?. I have a sidewinder 5000ESP that I think has a shortcut, because I am noticing that something weird happens with my headlights. One of the electric motor of the headlights keeps on working...
  9. Clausius2

    Aerogel, best insulator on Earth

    Today I went to the JPL at Pasadena, and I saw the Aerogel. It is said it is the best insulator on Earth. They used it for insulating the Mars Rover vehicles. But it seems that is weak when shear stress is applied. Do you know what are the current applications of Aerogel, and why is it not...
  10. Clausius2

    Analytic solution of this, Advice.

    I am looking for the analytic solution of this ODE (if it were one): s^2G''+sG'-(1+s^2+s\text{coth}(s))G=-4s^2e^{-s} I have solved this equation numerically, it only gives one physically realizable configuration rejecting conveniently one of the homogenous solutions. I don't have those...
  11. Clausius2

    My car and my battery

    My alternator broke down recently when riding, and the engine drained completely the energy of the battery. It was almost empty. I got the battery checked and they told me it was ok when recharged. Now I have it recharged, but should I replace it?. It is not brand new, maybe it's at the 60% of...
  12. Clausius2

    Hankel Transform.

    Hey guys, Do you have any advice of a place for learning about Hankel's Transform and its application to Laplace Equation?. There are a couple of lines of a paper in which I am stuck on, I don't know how do they do this stuff: Defining the operator...
  13. Clausius2

    Ideal Gas: Equation Of State in Diatomic Gases: still valid?

    That came out in my qualifying exam. The question was if a gas with rotational and vibrational energies enhanced, does obey the Ideal Gas Equation PV=NKT. You can answer with all the tools you have at hand. My comitee member didn't agree with me, but anyway I persisted in my answer and I...
  14. Clausius2

    Just Passed the Dept Qualifying Exam

    Just Passed the Dept Qualifying Exam!!! I am not going to tell you it was easy. It was a Hell. I went through Hell this afternoon. Four people in my commitee. I was being examined of three areas: Fluid Mechanics, Turbulent Flow, and Physical GasDynamics. Tough. The business of the Partition...
  15. Clausius2

    When can one assume Incompressible Flow?

    Incompressible Flow: Assumptions for its validity After a recent hot discussion brought to the board, I think it would be good to clear up this question. Firstly, it does not make sense to talk about an incompressible fluid. There are no incompressible fluids in the Nature, we can only...
  16. Clausius2

    Dissapointed with old closed minds in ME forum

    I have faced a couple of guys in the engineering PF that base all their analyses in their virtual experience in a company. No analytical demonstrations, no numbers, no concepts, only words and curriculums. I want let you know, PF administrators, that young people like me get dissapointed with...
  17. Clausius2

    The Matrix IV

    Does anybody know if they are preparing already the fourth part?. I rewatched the trilogy recently, and it's clear that the end of the third one is opened for another part. The Oraculus says that Neo may come back some day from the city of the Machines. I have to tell you something; I am Neo.
  18. Clausius2

    Rotation Energy Levels and Degeneracy.

    Solving the Schrödinger equation in spherical coordinates for a diatomic gas, one finds that the rotational energy leves are given by: \epsilon_l=K\cdot l(l+1) where l=0,1,2... is the rotational quantum number and K is a constant. It is said that each energy level shows a degeneracy of...
  19. Clausius2

    Perelman, Poincare Conjecture solved now?

    Perelman, Poincare Conjecture solved now?? Seems that this guy has solved the Poincaré Conjecture: He is supposed to get the Fields Medal in Madrid this year, in the next international congress of mathematics. But it is likely that he won't...
  20. Clausius2

    Your food habits, Americans.

    Ok, thanks to those for bearing with me the flames in the the scientist arrogance thread. I really appreciated your comments. I was in bad mood, but I think my bad mood is caused by your food!!!. :bugeye: Now talking seriously. I have noticed during my staying here that your food habits are...
  21. Clausius2

    Scientist Arrogance

    As some of you know I'm left my home land and I came here to do research. I'm mechanical engineer and ph.d. student. That means that I am able to work in another place and make more money (and may be more interesting things) than what I am doing right now. Why did I start with this business?. It...
  22. Clausius2

    Bittorrent initialization core failed

    Amazing, after downloading my first thing with Bittorrent, this program is not working on my computer anymore. I obtain the error msg: Initialization Core Failed. I tried to re-install the program several times, even doing a restoring of my system, but nothing works. Any ideas? Thanks
  23. Clausius2

    Debye Layer

    Just a question: I do know it is possible to have a debye layer in a electrolyte. But is it posible to have a Debye layer in air?. I mean, if I put a single charged particle in air, do I have a layer of ionized air surrounding it??. Thanks.
  24. Clausius2

    Calculating the equilibrium distance

    Hi there, Let's imagine a sphere touching a plane. Then, I may consider valid the law for adhesion coming from VDW forces: F=\frac{Aa}{6h^2} where A is the Hammaker constant, a is the sphere radius and h is the gap between the two bodies. My question is, is there a way of calculating...
  25. Clausius2

    Car Failure Advice

    NOOOO is not my Firebird what is wrong, it is the 93 Ford Aspire of my roommate. It suddenly shut down when driving, deccelerating and finally swtching off. The ignition is working, but the engine does not start. It does not start and stalls, only it does not achieve to start. It does not seem a...
  26. Clausius2

    Guys Rules for Girls

    Guys Rules for Girls!!!!! Were you thinking we have not any rule?. These are the ones as far as I am concerned: notation: (Otherwise she would be discarded) means I would never date a girl whose behavior is violating the rule. 1. If you're unhappy with something, say so. Don't expect...
  27. Clausius2

    Turbulence and Lorenz Attractor

    When one tries to have an insight into what the turbulence regime really is, one comes across the question of: is the turbulence a deterministic process or not? Even though we are able to simulate accurately turbulence with Direct Numerical Simulation (DNS) of the Navier-Stokes Equations, it is...
  28. Clausius2

    Experimental Fluid Mechanics Videos Series

    Hi everyone, Maybe this resource is new for someone. It's a collection of videos made in the 60's by the very best experimentalist scientists of the best universities of the United States. There you may watch how Taylor gives you a lesson in Low Reynolds Flow, how Lighthill gives a lesson in...
  29. Clausius2

    Automatic Transmission

    I've just bought an automatic transmission car (7 speeds), and I am used to drive manual cars. My question is the next: -do you have any advice for ensure a long duration of the transmission?. I mean, sometimes I don't know if it is correct to drive with the overdrive speed at low velocity...
  30. Clausius2

    My Firebird

    yeah, for those who have seen I've changed my avatar for a firebird, that's true, I am flying across america with a Firebird. I bought one. It's awsome. It's my firebird. It does not seem a car of a grad student, but you may take into account I am an spanish engineer, or so called "Sir Engineer"...