What is Sources: Definition and 537 Discussions

A tertiary source is an index or textual consolidation of primary and secondary sources. Some tertiary sources can be used as an aid to find other sources. The exact definition of tertiary varies by academic field.
Academic research standards generally do not accept tertiary sources as citations.

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  1. E

    Why the fascination with intermittent renewable energy sources?

    Maybe I’m missing something, and this thread is to at least try to drill down into this to help me understand what that something might be… Basically I do not understand the almost cult like fascination with intermittent renewable energy for utility scale electricity production. My current...
  2. A

    Quantum Good sources for the representations of the Poincare group?

    Weinberg QFT book aside, what are good sources for the representation of the Poincare group used in physics?
  3. P

    With two DC charging sources, are blocking diodes required?

    I have a simple 12vdc system on a boat with a single battery bank. There is a stock alternator on the engine and I've inherited a solar panel i'd like to install. I understand that most solar charge controllers have built in back feeding prevention, but will i also need blocking diodes on the...
  4. P

    A Understanding Spectral Coherence w/ Radiation Sources

    What is the relationship between spectral coherence with respect to a radiation source's mean wavelength and bandwidth? I have no idea how to estimate, given a particular radiation spectrum from a source, what it's spectral coherence is going to be.
  5. VVS2000

    Interference Pattern from two coherent light sources

    Can anybody explain why the bright and dark fringes exist during the the interference phenomenon from two coherent sources.. I wanted to know why that specific pattern occurs
  6. M

    Norton's Theorem with Dependent Sources?

    My question is: What is wrong with my working/ method (in the attached pictures) to find i_{sc} ? I can get the Norton equivalent from there, but seem to get the same answer as the solution scheme. Context: we are given the circuit depicted in the picture (initially with no connection between...
  7. M

    I How do ion sources in cyclotrons work?

    I've been learning about cyclotrons recently and have trouble understanding how the ion source works. I have done some research and found that duoplasmatrons are some forms of ion sources but i don't think that's legit. I also found something called RF ion sources, but not sure how they work. I...
  8. .Scott

    What a Shame we can't cite from popular sources

    Life would be so much more exciting. Here's one from UK's www.express.com: https://www.express.co.uk/news/science/1093099/NASA-asteroid-warning-asteroid-GD37-earth-crash-2019-date-nasa-asteroid-tracker Of course, it's all very sensational - and they do eventually specify exactly how likely this...
  9. ORF

    What limits the amount of renewable energy sources?

    Hello, I was told every country needs a constant electricity production source (like coal or nuclear powerplants), and up to some proportion, renewable sources (photovoltaics, hydro, wind turbines, etc). So, my question is: what limits the amount of renewable sources? (the grid, storage...?)...
  10. TachyonLord

    Sources of errors in a spectrometer experiment

    [Note from mentor: this lacks the homework template because it was originally posted in a non-homework forum.] I know this seems like a very dumb question but every other error I think of has been covered in precautions and the only errors I can think of are dumb ones. Help ! I had to plot the...
  11. Spinnor

    I Resultant vector field as sum of many sources

    Let us have some localized density of sources, S, in a plane, each of which produces a localized circular vector field. Let us work in polar coordinates. Let the density of sources, S = Aexp(-r^2/a^2) and let each source have circular vector field whose strength is given by exp(-(r-r_i)^2/b^2)...
  12. J

    This method may be more intuitive for some people.

    Homework Statement Question - Calculate the rate of energy transferred to the 1.5V cell during charging if the potential between X and Y is 1.9V Homework Equations P = VI The Attempt at a Solution I think I understand how to get the answer. If XY has 1.9V then the resistor will get 0.4V...
  13. T

    Small & Lightweight High Voltage Power Sources: Ideas?

    << Mentor Note -- thread moved to the Sci-Fi writing forum after starting in the technical forums >> Hey folks, I'm interested in the feasibility of providing high DC voltages (~kV) in a physically small and low mass package (~grams). The power source does not actually need to be very energy...
  14. S

    Correct statement about coherent sources and interference

    Homework Statement Which of the following statements is correct? a. coherent sources are not needed to produce interference fringes b. two coherent light sources do not always produce bright and totally dark fringes on a screen c. the atoms in a tungsten filament lamp produce coherent light...
  15. Hercuflea

    Half life from two identical radioactive sources cpm

    Homework Statement " Independent measurements are taken on two identical radioactive samples. On the first radioactive sample, a radiation detection system measures N decays on a radioactive sample during a total period of T. On the second radioactive sample, a radiation detection system...
  16. Cantor080

    Practices, Laws, or Principles of living longer

    I am starting to search data on what actions are to be made for living longer. I might have to know the working of human body, but it might take lot of time. Within the time I know the working of human body, and have custom actions for me to live longer, to eliminate me not do any of the random...
  17. G

    Inertial loads -- Sources of information needed

    I'm working with Aerodesign, and I want to study "Inertial loads" but I can't find books about the subject, do you know any? thank you
  18. B

    I Double slit one source same as no slits with two sources?

    Instead of using a single source and two slits, imagine just using two sources the same distance apart as were the slits... The two sources are controlled by a device that has two modes of operation, selected by a two position switch labeled D and R: D is "determined" - the emission from the...
  19. AchillesWrathfulLove

    When using the Mesh Current Method -- How to handle current sources facing the wrong way

    When using the Mesh Current Method and you encounter a loop with a current source that is going opposite to the mesh current do you write it down as a negative current source?
  20. Hans Nelsen

    B How Does Age and Distance Affect Light from Distant Galaxies?

    Since more distant objects are older, and the farthest objects we receive light from are billions of years old, or rather, their light is billions of years old, in what way, or how different would the distant universe be, if we could see the light it generates today? For that matter does light...
  21. Stephen Lanford

    Possible error sources in thermal conductivity experiment?

    Hello, my name is Stephen Lanford and I am currently working on a Physics II lab. I am solving for the thermal conductivity of four materials (glass, plexiglass, pine, and sheetrock) using data from thermal conductivity experiments. The experiments consist of a steam chamber at 100 C, a block...
  22. akaliuseheal

    Use of 4 floating current sources

    Homework Statement I have 4 resistive sensors thus I need to tie 4 floating current sources. Floating current source will give me output voltage linear to the resistance of a sensor. I know it is not the best solution but it is good enough. Image provided: Homework Equations None The Attempt...
  23. W

    Writing: Input Wanted Alternative energy sources? How about photons?

    I'm looking to get into the realm of science fiction writing and am currently working out how the main "SciFi energy source" works in this world I'm trying to make. Fusion reactors are the obvious go-to, but I wanted to get creative, that said: how plausible/effective would it be to directly...
  24. S

    Problem about power absorbed & dissipated by voltage sources

    Homework Statement Problem in Fig 2-18 and its solution: Homework Equations Passive Sign Convention, I think. The Attempt at a Solution Let's say i is counter-clockwise. Then, it's going from - to + of v_b. Why is there not an additional negative sign in computing p_b, and why is there one...
  25. Santilopez10

    Circuit problem involving sources and resistors

    Homework Statement The currents ##I_{{a}}## and ##I_{{b}}## of the circuit have values 4A and -2A in that respective order. A) Find ##I_{{g}}## B) Find the power dissipated by each resistance C) Find ##V_{{g}}## (voltage drop across the current source) D) Show that the power delivered by the...
  26. binbagsss

    Other Operations research, stochastic dynamic programming, sources

    My lecture notes and recommended textbook Hillier and Liberman are not enough for me. My methodology and formulation of problems still seems like too much guess-work. Can anyone recommend any good resources, lecture notes or textbooks, for stochastic DP? Many thanks
  27. B

    Maximizing Vacuum Power: Understanding the Effects of Parallel Vacuum Sources

    I have two vacuum sources each pulling 1 inHG. If I connect the vacuum sources to a Y-connector, with identical sized hoses, so that each pulls on one tip of the Y, will I get 2 inHG vacuum on the remaining hose, or will I get 1 inHG with more cfm? Thank you, B
  28. Mohrcircle

    Solving Freudenstein's Equation: Sources & Explanations

    These questions are going to be coming in exams. I have found info on derivation of freudenstein however I really don't know where to find info to solve for other three bullet points. Help would be appreciated in pointing me to the right source. Also: For cam-cam contact any book suggested or...
  29. Adiater

    I Double-Slit Interference w/ Separate Sources

    If you have two similar coherent sources which are separated from each other by a barrier. Now one source sends particles one by one into one slit and the other sends particles into the other in a double slit interference experiment. Now, the photons are always undistinguishable, so they should...
  30. M

    Sources of Error in a Speed of Sound Experiment

    Homework Statement Determine sources of error which could have affected the results. Some background information: The lab consisted of playing a tone generated by a tone generator above a standing open-closed tube which had water in it. The first harmonic was measured through a computer system...
  31. mastermechanic

    Video Sources for Anisotropic Hooke's Law

    Hello everyone, I'm taking Mechanics of Materials II this semester which includes Anisotropic Hooke's Law, Plane Stress & Strains, Mohr Circle and so on. I need a video source of these topics. The videos on youtube mostly have bad camera position. I want something like coursera stuff but there...
  32. sparkie

    Nodal Voltage Analysis with dependent sources

    Homework Statement All the data is on the sheet. I named the nodes V1 to V4, however I'm primarily evaluating in terms of V3 and V4. The x=V3 and y=V4 are for the systems solving I'm using. I've looked and looked at this problem, and seem to be hung up, but I suspect it is going to be on my...
  33. E

    I with this circuit -- 2 resistors and 2 sources....

    Homework Statement The problem is in this link https://www.chegg.com/homework-help/find-vo-io-circuit-fig-226figure-226-chapter-2-problem-7pp-solution-9780078028229-exc Homework Equations 3. The Attempt at a Solution [/B] 15=[io/3]+[io/3]+ [vo/12] I got this equation for the problem...
  34. L

    Help 1064 nm emitted from different sources of devices

    Are there any differences between 1064 nm emitted by Long-Pulsed Diode laser device and 1064 nm emitted by Long-Pulsed Nd:YAG laser device for hair removal? Assume that fluences, pulse durations & spot sizes of both devices are exactly the same, should the property, efficacy and side effects of...
  35. D

    Two AC Sources with One Transformer

    I want to program a little power grid game and have the problem of connecting things via transformers. Imagine the following setup: You can see the AC voltage sources as generators (or together with the resistor as a "consumer", if the amplitude is 0). What I need to figure out are the...
  36. J

    Why is there a diode between two sources?

    I have a situation like on picture in attachment. I want to know, why I have a diode between two sources? What will happen without diode? Thank you.
  37. J

    Solid State Sources to learn about Topological Superconductivity

    Greetings. Does anyone know about any good places to learn about topological superconductivity from? Thanks in advance!
  38. V

    Independent and dependent sources examples

    I would like to know if the following examples of independent and dependent sources are right and some further examples. Independent sources: Batteries, DC generators, Alternators, Photovoltaics. Dependent sources: Power electronic components (Diodes, Transistors, Thyristors), inverters, ups, cpu.
  39. K_Physics

    Relative Intensity of Various Light Sources - Lab Experiment

    Homework Statement I've linked my data table down below. My problem is the relative intensity column. From the table, the units of relative intensity are w/m/s. I'm assuming this is power/velocity, where velocity is the speed of light. However, nowhere in the lab manual did it mention the...
  40. ISamson

    Electricity sources vs. fossil fuels

    Hello, The issue of climate change and energy has been in the news for a long time. But are electric, chemical or renewable sources really more environmentally friendly than fossil fuels? Fossil fuels need to be burned, which produces CO2, which retains the heat from escaping our atmosphere, so...
  41. arkaddas

    AC Mains Distribution energized from multiple AC voltage sources

    Even though its possible to keep a bus charged from more than one AC voltage sources, what can be the consequences of doing so? My thoughts: - Assuming thst both the sources have similar (but not equal) phase and magnitude, we can expect small circulating currents. Which brings into question the...
  42. marsupial

    The validity of the interconnection of ideal sources

    Homework Statement Sorry in advance for such a basic question, just starting my first electrical engineering course. The question asks if the interconnection of ideal sources is valid. The next part of the question asks us to verify that the total power developed in the circuit equals the...
  43. Majorana

    TRAPATT diodes -- looking for sources of parts

    Hello everybody, I wish to do some experiments with TRAPATT (TRApped Plasma Avalanche Triggered Transit) diodes, but after much googling I was unable to find the name of any manufacturer of such diodes. Anybody with useful pieces of info?... Thank you! :bow:
  44. chopnhack

    KVL/KCL with two sources - can a loop have both sources?

    Homework Statement In the circuit shown, find (a) the current in each resistors (b)The power dissipated in each resistor. Homework Equations V=IR, P=VI, KVL and KCL The Attempt at a Solution See attached. I was going to post this in the main section as its really a question about whether you...
  45. T

    AC Mains meter circuit design for energy sources....

    What circuit design is used to ensure that the renewable energy source does not begin to absorb energy from the grid (for instance, when its terminal voltage drops below the distribution line voltage)?
  46. A

    Source transformation, current & voltage sources

    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Hi, I was working on a the source transformation and i got to the part where there are two current sources in the circuit. The current sources were added together (giving they were going in the...
  47. T

    UPS that accepts multiple power sources

    Hi, I'm looking for a device that is able to provide stable power and alternate between power sources. UPS, no matter how good they are, they usually still have several millisecond downtime during outage, switching from power grid to backup battery. I want a device that can accept power from...
  48. BAJ

    Parallel circuit of current sources

    Assume I have a parallel circuit of current sources with 5 current sources generating 1mA each. Therefore from both the terminals I will get 5mA total. Now if I add a battery to one of the terminals where current(i) will flow into my circuit. If i = 50mA, will I get 55mA current from another...
  49. C

    Kinematics physics lab help sources of error

    1. The problem statement of my lab I have this physics lab where I have to find the maximum velocity and maximum acceleration of a high school student sprinting/running using carbon tape and a spark timer. Which I already did. Now I'm having trouble developing my sources of error section. I hope...
  50. V

    Circuit with two voltage sources, finding voltage at nodes

    Okay, so why is it that Vc assumed to be 12v - 0.7v (D1), how about contribution from the 9v battery?? Why is this not affecting the voltage at node C? Why Vc isn't 9v - 0.7v (D2) = 8.3v?
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