What is Sem: Definition and 27 Discussions

The Sem–Loire France cycling team was a French professional cycling team that existed for four years from 1980 to 1983. Although a small team, directeur sportif Jean de Gribaldy directed the team to success in various classic races and in stage races such as Paris–Nice and the Tour de France as well as the French championships.

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  1. Dario56

    I How Does SEM Compute Sample Structure?

    In SEM, secondary electrons are emitted from the surface of the sample computing surface structure when they reach detector while backscattered electrons give information about structure and chemical composition of internal parts of the sample. However, what I don't understand is what does...
  2. Tertius

    A Find SEM Tensor from Lagrangian of Temporal Variable

    It seems the field φ(t, xi) could be integrated over all space to form a single temporal variable (which isn't a field anymore, but is just a function of time) as follows: Φ(t) = ∫φ(t, xi)dxi Suppose we then assume a Lagrangian from this temporal variable to be: L1 = -1/2 Φ'(t)2 + 1/2 b2...
  3. D

    Where does one shop for SEM components?

    I am working (as an undergraduate) assisting in the repair of a JEOL Scanning Electron Microscope. Without going into too much detail, some components of the SEM control system may be damaged and need complete replacement. I am working with an instrument engineer who has mentioned that he has...
  4. J

    Gemstone's surface pattern: any ideas?

    2 SEM images of gemstones: emerald and ruby (Electron Miscroscope with Secondary Electron detector, (which "takes picture" of surface layer (~0.5 um) both the elemental composition and relief)). Dendrites - it is clear (not me, but in general), what creates other patterns? * trace elements? -...
  5. O

    Any idea how to bake the column of a SEM?

    I am an undergraduate researcher and my university had an SEM donated to us by DOW chemical. It since has been without power and we have to bake the column and the gun chamber. Contacting the company they estimate $17k to send someone out to do it for us. I'm having difficulty finding material...
  6. B

    Prepare Crystal Sample for SEM Analysis: Ca5(PO4)3OH

    I have a crystal sample that I wish to analyze using scanning electron microscopy (SEM) but is not initially in powder form. What are the proper steps to be taken to prepare the samples for analysis? The substance, I believe, is mainly hydroxylapatite, Ca5(PO4)3OH. Thank you!
  7. C

    I Why is the resolution of TEMs and SEMs not smaller?

    I was wondering if someone could offer an explanation as to why TEMs and SEMs have practical resolutions several orders of magnitude less than what is predicted by the Rayleigh Criterion. This of course comes from my own calculations of the Rayleigh Criterion assuming an electron is accelerated...
  8. S

    I Structural differences between W, WC, and W2C?

    In my research group, I'm tasked with determining the purity of a tungsten sample sent from a supplier. Using FIB, we cut a 20 by 20 by 20 micron well into the sample and tested a wall of the well about 10 microns down from the surface. After taking a spectrogram, there seemed to be a large...
  9. T

    Yes, the derivative of log(x) is 1/x.

    Hi, this isn't exactly a homework question, but this seemed like the most appropriate place to put it. Homework Statement I have an equation in the form: log(a)=log(b)+c. I also have standard errors (SEMs) for b and c. I want to find the standard error for log(a) (i.e. log(a) +/- E(log(a)))...
  10. S

    Uncovering the Strength of SEM's Electromagnetic Lenses

    Does anybody happen to know the strength of the electroMAGNETic lenses of a scanning electron microscope? I was thinking of using solenoid coils, which would be enough if I am willing to increase the focal distance, but the lenses on SEM's seem far larger.
  11. E

    Engineering Want a BME 1st sem book (S.I. unit)

    I'm a mechanical engineering student 1st yr . I need suggestions regarding books for basic mechanical engineering and engineering mechanics . A book with basics n proper language.
  12. S

    Exploring SEM Imaging: Cost & Advancements in Raster Scanning

    Looking at Ben Krasnow's youtube video on breaking down the parts and general cost for a scanning electron microscope, he lists a raster scan generator, is that able to produce the highest resolution images still? Or is there another more modern technology for this purpose? Otherwise, how has...
  13. S

    Imaging CDs, DVDs or other optical media under SEM

    Greetings, After getting some training I have access to my universities SEM facilities and I would like to image CDs and DVDs with it(, I know that these consist of many layer which may not be transparent to the e-beam so they might need some preparation. Does anyone have any idea? I am...
  14. A

    Kikuchi lines Vs Kikuchi bands (EBSD in SEM)

    Good day, anyone can point out to me how kikuchi bands are formed? And I mean bands, not lines. I finally managed to understand (I think) kikuchi lines: bragg diffraction is decreased in the incident direction (defecit=darker line) and enhanced in the "bragg" direction (excess=brighter line)...
  15. C

    Help me identify this mystery structure in my SEM image?

    Hey all, As the title suggests, I've found some recurring structure on an SEM image and I can't for the life of me figure out what it is. I took the image this morning. Here she is: http://i.imgur.com/nFuBsW2.png Here's a larger, more zoomed out and higher res version. A few more of...
  16. L

    SEM Project Ideas for Undergrad

    Hey Forum, So I am in my final semester in my undergraduate program for Biology. I am going into bioimaging field of study, so I took on a research elective utilizing a scanning electron microscope. I am also taking a one credit directed study in microbiology which is used to combine and...
  17. R

    Electromagnetic lens for an SEM

    Does anyone know how the machining tolerance in the construction of an electromagnetic lens affects resolution in a scanning electron microscope?
  18. G

    First sem. calc physics: Cable tension (vectors and acceleration)

    So, I'm trying to understand how tension works between a cable. No, not homework. A book example. I have the answers. a = 0.679 m/s2 t = 12s So, I've seen the free-body diagrams. There is tension, sure, but the tension is in perpendicular directions. The book gives examples of tension in a...
  19. jfy4

    Understanding the Trace of the SEM Tensor

    Hi, Let T_{\alpha\beta} be the stress-energy momentum tensor. What does g_{\alpha\beta}T^{\alpha\beta} mean? I have always thought of the Ricci tensor and the SEM as the same thing essentially, but the Ricci scalar essentially assigns a number to the curvature of the manifold, what does T...
  20. J

    Courses How is my course load for UBC First Year Applied Sciences? 5 courses first sem, 7 cou

    Here is my timetable: [PLAIN]http://img171.imageshack.us/img171/5438/ubc.png I have 25 hours or classes for my first term and 26 hours for my second term. HOWEVER the biggest problem with this is that I have 5 courses for my first term and 7 for my second. Do you think I can handle 7...
  21. S

    Topics to study for BE (B-Tech) First Sem

    Hello! I am from India and I want transfer in any US university next year. For that I think I need to give SAT and TOEFL but as I want transfer I also need to perform excellent in the college to which I'm going to take admission now. It's nearly 15-30 days left for my admission and so I want to...
  22. P

    Is color added to SEM and TEM images in post-processing?

    I saw in some papers SEM colored images. Does anybody have an idea about the software that may be used?? and how? thanks
  23. F

    An intro question about the magnification factor of an SEM

    An intro question about the "magnification factor" of an SEM A scanning electron micrograph of xylem vessels in a corn root shows the vessels magnified by a factor of 600.? In the micrograph the xylem vessel is 7.0 cm in diameter. (a) What is the diameter of the vessel itself? (b) By what...
  24. X

    SEM Q&A: Get Answers to Your Questions Now!

    I have two questions about SEM which is in the attachment, need your instructions...thanks in advance..
  25. S

    Must SEM = Theoretical Framework?

    Based on theories, I constructed a theoretical framework. After I collected data from respondents, the data seems not fit accurately with my initial theoretical framework. I want run analysis on the data and certainly, the Model of data (i'm using Structural Equation Modeling) is different...
  26. E

    What is the coolest nano-sized object you want to see a picture of?

    Okay, this is kind of a contest. Name the something nano-sized you would like to see a picture of. I will consider all the submitted ideas, and scan the object, that would make the coolest picture, for all to see. Why am I doing this? Well, I want to have a cool SEM picture (that I...