Identification Definition and 92 Threads

  1. J

    Unknown component identification

    http://www.adafruit.com/blog/2012/05/25/handy-arduino-r3-pinout-diagram/ What is the component just below the USB connector, and to the left of the SOT transistor? I've seen something like this on a few other boards, but I can never place exactly what it is.
  2. B

    Calculating Q Matrix for Extended Kalman Filter Identification

    Dear people, I want to implement the Extended Kalman Filter for identification. I have a model of the system and I want to estimate the states. My question is, how can give the Q Matrix, I mean, how can I calculate the elements of the covariance matrix related to the dispersion of the system...
  3. R

    Equipment Identification please.

    Hi Could somebody please tell me what this is? It stands about 1/3 M high, has a spout just above the larger bottom section and the lid with a chimney in comes off to reveal a narrower copper cylinder inside. Is it Hope's? Thanks in advance Caroline
  4. Evo

    Why Do Pennsylvanian Rock Formations Appear as Strips?

    A number of people have said they are interested in this topic. Please posts any pictures, information or questions about rocks or fossils here. I'll start off with some odd formations in rock here from the Pennsylvanian period (318.1 to 299.0 mya). They appear to be strips of wood, but...
  5. T

    News Tax fraud in Individual Taxpayer Identification Number program

    This is the kind of stuff that makes my blood boil. http://www.foxnews.com/politics/2012/08/08/treasury-inspector-general-says-changes-are-needed-to-detect-fraud/?test=latestnews Summary: FWIW, ITIN is Individual Tax Identification Number 154 Mailing address used for 1,000 or more ITIN...
  6. A

    Old Physics Apparatuses - Identification Help

    Hello, I am an undergrad in my senior year at a small liberal arts college. This summer, I have been given the task of assessing our physics labs. Specifically, we have a lot of old equipment that the professors don't know much about, and they would like me to find out if it works anymore...
  7. H

    System Identification: Finding Transfer Function w/ Graphical Methods

    Hello, I have to find the transfer function of a given model (matlab). My task is to determine this function, by means of a step response of the system. I have to use graphical methods tot get the parameters, the proces itself is a high order proces with non minimum phase...
  8. H

    Convergent Series: Introduction & Identification

    I need to know about converge series.For example how to identify a converge series.Plz explain.
  9. F

    Identifying a Non-Linear Parameter Varying System

    Hello guys, i am trying to identify the following non linear parameter varying system. \begin{equation} Y_1(t_{i})}=\frac{Y_1(t_{i-1})+\Delta t.k_{1}.Y_2(t_{i-1})}{\left(1+\Delta.t.\left(k_{1}.Y_2(t_{i-1})+k_{2}.Y_3(t_{i-1})\right)\right)} \end{equation} \begin{equation}...
  10. F

    Thanks again.Identification Algorithm for Parameter-Varying System?

    Hello everybody I started recently working on an engineering problem that requires as a first step, the identification of the system. I already have a model which is a set of differential and algerbraic equations. Unfortunatelly, the system is a parameter varying one, and the aime is to...
  11. D

    Identifying Unknown Part: 60 Ohms, 50 nF

    Hey guys, I have no idea what in the world this part is. I Ohmed it out and it is about 60 ohms. I measured capacitance and it is around 50 nF. My first thought when I saw it was that it was a capacitor. But 50 nF... I talked to our technician and he mentioned a PolySwitch. I am a little...
  12. Matterwave

    Understanding the Identification Between SU(2) and O(3) Groups

    Hello, I'm reading Ryder's Quantum Field Theory book, and I'm reading the preliminary part where he discusses a little bit of Groups before he introduces the Dirac equation. So, as an example, he is talking about the identification between the SU(2) group and the O(3) group. Before he gets there...
  13. C

    Why Do Flame Tests Only Identify Metals?

    Flame tests are used to test the color that a metal produces when heated and the electrons release energy when falling back to the ground state. This i understand, but why does the procedure only test the metal part of the salt? In other words, why does the anion part of the ionic compound not...
  14. F

    What type of plastic is this and where can I find it?

    Hello, I have somewhat of a difficult question. First of all I have to say I am not an engineer. I need help in identifying this type of plastic. I am well aware that visual identification alone is almost impossible but any help would do. If possible, could one provide a supplier of this kind...
  15. P

    Picture Identification: How to Tell a Chamfer From Rounded Corners

    I attached the problem, how can you tell? nvm , i think it's a chamfer because the corners aren't rounded
  16. B

    A Binary Operator Symbol Identification.

    I am curious what the wikipedia page <http://en.wikipedia.org/wiki/Pythagorean_addition> is referring to when it qoutes that symbol " a Little X in a Circle ", It says and I qoute the binary operation a "that symbol" b = sqrt(a^2 + b^2), Pythagoreans Hypotenuse. Much abliged.
  17. FtlIsAwesome

    Defining Nerd, Dork, or Geek: Criteria for Identification

    I would like for you to suggest possible criteria for determining if someone is a nerd, dork, or geek. Those can be three different things. Here are some thoughts I had a few days ago: "I decide to go on Physics Forums instead of playing Halo. That proves I'm a nerd." (Halo's awesome by the...
  18. C

    Identification of Compound:Spectral Analysis

    1. Organic compound having molecular formula C2H5O2N shown IR frequencies- 3428(sharp peak),2917,1886,1793,3357(Broad peak),145,1184. Identify the compound and the possible structure. 2. Table of frequencies of corresponding groups. [b]3. I have tried to identify the frequencies...
  19. S

    System identification: suspension parameters

    I need to estimate the suspension parameters (i.e. spring stiffness, damping coefficient and so on). So I have measured the acceleration at the top and at the base of the suspension during ground excitation. I have used a random excitation. The matter is the problem is nonlinear due to air...
  20. L

    Curved mirror identification & magnification question

    Homework Statement I can't seem to figure out whether I'm dealing with a + or - radius value. Anyways here's the question: An object 5.0 cm tall produces an image that is 7.0 cm behind the mirror. If the radius of the curvature of this mirror is 10.0 cm, what is the magnification of the...
  21. M

    Identification Space: Is A Cone?

    Is this a cone after Identifaction? Let A = (I × I)/J where J = (I × {1}) ∪ ({0; 1} × I) ⊂ I × I
  22. A

    Fourier Frequency Identification

    I am a high school physics teacher and was thinking of demonstrating to students how frequencies of complex waveforms such as notes of instruments can be identified using a Fourier transform. I haven't done Fourier transforms for a while and was quickly re-reading about them earlier this...
  23. R

    What characteristics distinguish major classification groups in biology?

    Hello everyone.. I have got an assignment for biology.. I've done Task 1,2 but i need help with Task 3.. and it says.. Task 3 carry out research using different sources. Explain how the characteristics you used to produce your identification key differ from those which are used to...
  24. G

    Particle identification in detectors

    Hello: Can anyone please tell me how do they identify the particles in the detectors?+, for instance, how do you know if an electron is an electron and not a muon or some other negative charged particle in a detector (without using magnetic fields)?
  25. slider142

    Insect Identification: ID a 3-4cm Long Insect

    We were walking down a Brooklyn sidewalk the other day under several trees when we spotted this insect lying motionless (except when the wind blew, it moved its legs a little to rotate itself). We didn't get too close, as it looked like it could give a bad sting. It has two pairs of long veined...
  26. C

    How Can I Identify Ions in a Mixture During a Practical Experiment?

    I am prepare for a practical experiment, this is a practical experiment aim to identify the anions and cations in the solution, and those ions are choosed from Pb, Ba, Ca, Cu,Fe2, Fe3 and CO3, Cl, PO, SO, NO3. where can i find the solubility in water for any ionic compound that can be formed...
  27. M

    Two torus identification problems

    1. Compute the fundamental group of the space obtained from 2 two-dimensional tori S1 x S1 by identifying a circle S1 x {0} in one torus with the corresponding circle S1 x {0} in the other torus. Am I right in thinking that the resulting space is S1 x S1 x S1, and hence the fundamental group...
  28. P

    Riemann Integral Identification from Sum

    Hi There Everyone I am studying undergraduate calculus in first year. My question regards the rules for identifying a limit sum as a Riemann sum and therefore a definite integral. The book we are using says that when choosing \inline \large c_{i} for some f(x) , if \inline \large x_{i -...
  29. M

    Ground Roll Identification and Fresnel zone

    (1) How do you identify Ground roll on a shot record? Is it just the polarized nature of the ground roll that leads to its recognition on a shot record? (2) What is the importance of the Fresnel zone? and What does it depend on?
  30. P

    Electronegativity and element identification

    As part of the exploration of one of the moons of Jupiter, a probe digs under the surface, where it finds a pocket of gas. It starts to do some on-board experimentation. The data stored in the probe's computer include the following table of Mulliken electronegativity values of gases. Element...
  31. matthyaouw

    Sidoarjo mudflow, well blowout identification.

    I've been studying the Sidoarjo mudflow / Java mud volcano / Lapindo mudflow / Lusi pretty thoroughly in recent weeks. One of the key issues behind the disaster and relief effort seems to be a question of blame- if the event is natural the money for the relief effort must come from the...
  32. D

    Identification of group 2 metal salts

    Hi, I carried out a couple of experiments with unknown group 2 salts; X and Y I added dilute NaOH to each of the salts which were now mixed with 1cm^3 of water; Y formed a precipitate (initially the solution was colourless as the solute had dissolved) whilst X turned colourless (X's...
  33. E

    Exploring the Topology of a Two-Dimensional Torus and a Rolled Cylinder

    What is the space resulting from the identification (x,y) ~ (x+2piR, y+2piR)? How is it different from the space resulting from (x,y) ~ (x+2piR, y) (x,y) ~ (x, y+2piR), which is a two-dimensional torus (a donut)
  34. S

    Distinguishing Particles & Crystals in Rock Identification

    Homework Statement I saw a division in a rock identification chart given to me by a lecturer.It says, Rock made of particle or crystals.I was wondering wat is different in both of these two and how to distinguish between them and identify them Homework Equations The Attempt at a...
  35. I

    Simple trig identification equation question which i can not answer

    Homework Statement Solve for X Homework Equations 2sin^2x - cosX - 1 = 0 The Attempt at a Solution I have gone in this order I turned 2sin^2x into 1 - cos2x so 1 - cos2x - cosx -1 = 0 This turns into Cos2x + cosx = 0 I don't know what to do next... could...
  36. S

    Surface formula identification

    Homework Statement Identify the surface given by the equation 4x^2 +4y^2 −8y −z^2 = 0. Homework Equations x^2/c^2 + y^2/c^2 - z^2/c^2 = 1 (textbook definition for hyperboloid of one sheet. The Attempt at a Solution I know just by looking at the textbook formula what surface...
  37. N

    Gene Identification: How Are Genes Identified?

    The way I understand it, genes are rather sparse within a strand of DNA. The human genome, for example, has a few thousand genes in a strand of 3.5 million A,C,G,T bases. I also understand that genes code for proteins through RNA but, again, most of the DNA is noncoding. My question is, how...
  38. P

    Raman spectroscopy is Single molecule identification

    Raman spectroscopy is "Single molecule identification" Hi , I heard that the speciality of Raman spectroscopy is "Single molecule identification", it'd be really great if somebody can tell me HOW! because its surely going to be a question in my exam! Thanks in advance.
  39. wolram

    Sisters of the Hood: A Character Identification Guide

    Can you identify any of these Sisters of the Hood ?
  40. C

    Identification of an object in the sky

    I saw a star just yesterday night about southwest in the sky, and when viewed through my telescope it was flashing red and blue.It was no plane for it was there all night.Is this caused by the atmosphere?If not what is it?
  41. G

    Help with Isomer Identification Using NMR of Xylenes

    I was wondering if someone could please help me with my lab. We are synthesizing NMR shift reagents in order to determine what isomers are present in a mixture of xylenes. I have the NMR and I can't figure out how to determine which isomers are present. If I have the NMR of o,m,p-xylene by...
  42. wasteofo2

    News The DMV has stricter identification requirements than boarder security does.

    I just got my learners permit today at the DMV, and brought a photocopy of my birth certificate as a form of identification. They did not accept it and said I needed an original document with the state seal stamped on it to proove that the document is real, so my dad and I had to go to the town...
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