What is Process: Definition and 1000 Discussions

A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic.
Things called a process include:

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  1. D

    B Question about Neon-burning Process

    During the neon-burning process in stars, why do two Neon-20 atoms fuse into Oxygen-16 and Magnesium-24 instead of forming Calcium-40?
  2. T

    I Relation between change of pressure and temperature in adiabatic process

    In case of adiabatic process, we all know that the relation between temperature and pressure and that's given below: P. T(γ/(1-γ)) = Const. therefore, P = Const. T(γ/(γ - 1)) or, ΔP = Const. (γ/(γ - 1)).ΔT(1/(γ - 1)) It's just an attempt to find out the relation. Don't know how much correct I...
  3. S

    Correct statement about thermodynamics process

    I know process B absorbs heat but I can't determine the heat of process A. In adiabatic process, Q = 0 but process A is not adiabatic. I only know both W and ΔU will be negative for process A but how to know Q? Thanks
  4. singularcell

    Efficiency and Temperature in Heat Engine Cycles: Approaching Parts B, C, and D

    I didn't have much trouble with part a but I'm struggling with b,c, and d. I considered the efficiency formula for a heat engine e = work done by engine/ qh but i am unsure of how to approach it. for part c) not sure how i can get to Tc without knowing Th for d) my gut is telling me 5/2 but i...
  5. E

    Finding ##U## given information about an adiabatic process (Callen)

    I was unable show that ##PV^k## must indeed equal some function of the entropy, ##g(S)##; maybe doing so would make things easier? I proceeded as below. If we assume (as is almost surely intended by Callen) that in the given adiabatic (##d Q = 0##) process we are taking ##N## as constant and...
  6. M

    I Laser linewidth in a STIRAP process

    Hello! In a STIRAP process, for the right parameters (assuming a ##\Lambda##-type transition), the lifetime of the excited state doesn't come into play, so one can achieve very narrow linewidths of the measured transition of interest, regardless of the linewidth of the intermediate, excited...
  7. D

    Rate of cooling of aluminum parts after a glycol heat process

    I work for an aerospace supplier across different departments. I was recently shown how the production workers straighten aluminum parts after a glycol heat solutionizing process. The aluminum parts undergo a heat treatment for a few hours and are quenched in glycol. I can't get too in-depth...
  8. Z

    Chemistry Creating KF Molecule from Neutral Atoms: A Process of Ionization and Binding

    Let's think now about the energy to create a KF molecule from neutral atoms. First we need to ionize both K and F: K loses an electron and F gains an electron. Then we have to bring the ions together. The first ionization energy of K is 418 kJ/mol and for F is 1681 kJ/mol. The electron...
  9. rogdal

    Deriving the kinetic energy flux in an effusion process

    I could not find any derivations in the litterature, except for the expected value of the energy flux expression itself: $$\overline{\Phi_{effusion,\epsilon}} = \overline{\dot{N_{ef}}}\overline{\epsilon_{ef}}=\frac{3Nl}{2A}\sqrt{\frac{(k_BT)^3}{2\pi m}}$$ I've started off by calculating the...
  10. LUFER

    A How does the dry process work using porous silicon?

    I'm having trouble finding in the literature specifically about the porous silicon process using the dry method instead of the more common wet method that is used. wet process Using porous silicon to promote wet thermal oxidation uses the process electrochemically will allow water molecules to...
  11. Leo Liu

    Mathematica [Mathematica] How to use for loop to process a list of data

    Hi. I am writing a program in Mathematica that reads a xsl file from excel, then processes it by solving an equation, and lastly turns the processed data into a list for exporting. Context: Finding the maximum speed of a model plane at different altitudes (density). Screenshots of the code and...
  12. C

    Help Calculate Work Done in Adiabatic Process & Fill Table

    (picture of diagram below)So the task goes like this: gas is ideal. Process 3->1 s adiabatic and in process 1->2 work done is 1200J. Fill the table. I don't know how to calculate work done in an adiabatic process because p2 and V2 are not given and I don't know gama(Cp/Cv). I know that deltaU...
  13. A

    Poisson random process problem

    Hello all, sorry for the large wall of text but I'm really trying to understanding a problem from a study guide. I am quite unsure on how to approach the following multi-part problem. Any help would be appreciated. Problem: Useful references I'm using to attempt the problem My attempt: For...
  14. T

    I How does a process of a Raman transition break quantum entanglement?

    I'm reading this article about quantum entanglement, and the author writes about a process in a Raman transition which would break the entanglement, and I'm interested about how it breaks the entanglement. So the passage which I'm interested in begins with: "The answer is to do an operation...
  15. A

    A The name of the process underlying distributons with a hazard rate

    In the exponential distribution, the hazard rate is constant. The hazard rate does of course not always have to be constant, but can also be a function of time, which then leads to different distributions. But my question is: what is the stochastic process called that underlies this type of...
  16. F

    I Random variable vs Random Process

    Hello, When flipping a fair coin 4 times, the two possible outcomes for each flip are either H or T with the same probability ##P(H)=P(T)=0.5##. Why are the 4 outcomes to be considered as the realizations of 4 different random variables and not as different realizations of the same random...
  17. LUFER

    What is the Electromagnetic Cross Section in this plasma deposition process?

    What is Electromagnetic Cross Section? (shock section) Hello, I have a question regarding the manufacturing process of electronic components in the case of the silicon deposition and corrosion process. My biggest doubt is the behavior of the plasma interacting in the reactor, I don't know if...
  18. kolleamm

    Could we filter out diseases with a process similar to dialysis?

    I was wondering if it would be possible to remove diseases such as cancer from the blood with a mechanical device similar to the one used for dialysis. When the blood passes through the device certain cells would bind to the walls that have just the right binding sites so that they get stuck...
  19. Y

    Programs Help Understanding the PhD Application Process

    So if I'm understanding correctly, companies provide grants to universities to conduct certain research. The professors oversee the grants and have PhD student help contribute to the research under that grant. Based on this, it seems that PhD students don't conduct research "any question" they...
  20. Simobartz

    Entropy due to this irreversible process

    I think the solution is: $$dU=\delta W_{prop}$$ $$dU=TdS-PdV$$ $$dV=0$$ then, $$TdS=\delta W_{prop}$$ and so $$dS=dU/T$$ and by the way, it correct to say that, if the transformation between the initial and the final state would happen in a reversible way then the heat transfer could be...
  21. A

    B Creating a Wormhole: Process & Theory

    Black hole is real in nature and we know what is reason of it. If energy concentrate in sphere with radius which less gravitational radius then second cosmic velocity is speed of light and create black hole. We know process which can create these. If we know it we can realize quantum black hole...
  22. A

    Chemical plant design and construction

    Got some good resources on Chemical plant design and construction. A Chemical plant design and construction. B Chemical plant design and construction.
  23. Astronuc

    In Medieval Africa, A Unique Process for Purifying Gold With Glass

    Medieval Africans Had a Unique Process for Purifying Gold With Glass And scientists in Illinois have recreated it. https://www.atlasobscura.com/articles/medieval-african-gold Mansa Musa, emperor of Mali from 1312 to 1337, was widely known for his vast wealth in the form of gold deposits...
  24. P

    A Why Is Dissociation Rate Proportional to Current Raised to the Power of N?

    Hello everyone, I am looking for a simple intuitive explenation why the disociation rate is proportional to current^(N) where N determines the N-electron process in Fig. 4 of this article: B. C. Stipe, M. A. Rezaei, W. Ho, S. Gao, M. Persson, and B. I. Lundqvist, Phys. Rev. Lett. 78, 4410...
  25. K

    MHB Could use help, know the answers but with the process and equations

    A normally distributed data set has a mean of 25 and a standard deviation of 2. Which percentage of the data falls between 23 and 25? A given data set is normally distributed with a mean of 200 and a standard deviation of 5. Which two values does 95% of the data fall between? A and B are...
  26. S

    B Process of a sun changing into a white dwarf

    This is part of the text from the link: I want to ask several things: 1. From the second paragraph: "As soon as the sun begins to burn more hydrogen, it would be considered a “red giant”. " But from first paragraph: "But when the star has nothing left in the core to burn, gravitational...
  27. K

    I Help Understanding Luminance Calculation Process

    Hello all, I have a system that consists of: A projector with a known position, orientation, and brightness (luminous flux, I guess - units are lumens), A lens with known distortion characteristics (i.e. a known light ray vector for every point on the projector's image-generating panel) A...
  28. questionmonkey123

    Constant pressure process (piston) on gas violates Newtons 2nd law?

    I often see this set up in thermodynamic problems and need clarification on how Newton's Laws are involved for the piston: Gas inside a piston cylinder (1) is heated expanding the gas and raising the piston (initially at rest) to a height (2) in a constant pressure quasi-equilibrium process...
  29. E

    Cyclic Process for Ideal Gases

    Hello there, is my solution for part d logically correct? Here is my attempt at the solution : Part a : where : P1 = 3P2 Part b : Since P1=3P2, therefore, T1=3T, where T=300K. Thus, T1=900K Part c : Because the final pressure at the end of the cycle is exactly the same as the pressure at...
  30. A

    What is the process of QM studies? (Not a simple question)

    New physics guy.(This means totally unknowledged and ignorant.) I've been surfing google scholar,researchgate etc. Seeing many exotic articles,claming things like 1.unitary quantum mechanics fails to describe dynamics,so is ruled out. 2.quantum randomness is illusional! 3.we can recover...
  31. Viona

    A Process of Successive Approximations

    I was reading in the Book: Introduction to Quantum Mechanics by David J. Griffiths. In chapter Time-Dependent Perturbation Theory, Section: Two-level system. Every thing was fine till He said He will solve this equation: by a process of successive approximations. I have no idea what this...
  32. C

    MATLAB Generation of a Gaussian a random process with Matlab

    Hello everyone. I am currently working with Matlab. I have a 2D gaussian kernel constructed using the muKL technique (first attached figure). I want to use it to generate realizations of a gaussian random process using the KL theorem. For that, I obtain then all eigenvectors and eigenvalues of...
  33. LCSphysicist

    Understanding Scattering Process in QFT Integral

    I have been studying scattering process in QFT, but i am stuck now because i can't understand how this integral was evaluated: $$\int dp\space \frac{1}{\sqrt{p^2+c²}}\frac{1}{\sqrt{p^2+k²}}\space p² \space d\Omega \space \delta(E_{cm}-E_{1}-E_{2})$$$ Where Ecm = c + k, E1 is the factor in the...
  34. Krokodrile

    Chemistry Work, temperature and energy in a constant pressure process

    So, the Cp and Cv its very confusing for me. But, i understand what's its happening in this process, so, i use the logic and first i obtain a ecuation for obtain the final temperature ecuaticon: Q=m*C*△T Q=m*C*(T2-T1) T2=(Q+T1)/(m*C) If the process its in constant pressure, i use the Cp valor...
  35. A

    Calculating work and heat transfer in this Carnot process

    Hey guys! This is problem from Callens Thermodynamics textbook and I'm stuck with it. My goal was to get a expression for the entropy ##S## which is dependent on ##T## so I can move into the ##T-S##-plane to do my calculations: I startet by expressing the fundamental equation as a function of...
  36. TonyCross

    Mixing Newton's law with Adiabatic Process

    I have attached an image showing the perimeters of the problem. I have included what I think is the solution, could someone please take a look and tell me if I am on the correct path, in the solution I am taking Joules as a common term to attempt to solve the question. The gas I have used is N...
  37. E

    I A bit confused with this question about the Penrose process

    The first two parts to the question were as follows. If a vector field ##\xi## preserves the Maxwell field then ##\mathcal{L}_{\xi} F = 0## so by Cartan's magic formula ##i_{\xi} \mathrm{d}F + \mathrm{d}(i_{\xi} F) = 0##. But since ##\mathrm{d}F = 0## then ##\mathrm{d}(i_{\xi} F) = 0 \implies...
  38. J

    How to calculate initial pressure and temperature - adiabatic process

    Im confused on working backwards so to speak to find adiabatic work. To find work for this adiabatic process, I either need to know the change in temperature OR the initial pressure (I think?). The issue is that I don't know either the initial temperature nor the initial pressure so I am not...
  39. C

    Help with Material Selection Process

    Hi all, I'm working on designing a device, and I'm having trouble with material selection for a shaft, modeled below. I have found the maximum stress due to bending on the shaft in question by using σ_max = (M_max*y)/I where σ is stress, M is bending moment, y is distance from the neutral...
  40. bardia sepehrnia

    I How can a process be isentropic but not reversible or adiobatic?

    In the book for our thermodynamics, it states that a process that is internally reversible and adiabatic, has to be isentropic, but an isentropic process doesn't have to be reversible and adiabatic. I don't really understand this. I always thought isentropic and reversible mean the same thing...
  41. mcas

    Find the change in entropy for an ideal gas undergoing a reversible process

    We know that $$dU=\delta Q + \delta W$$ $$dU = TdS - pdV$$ So from this: $$dS = \frac{1}{T}dU + \frac{1}{T}pdV \ (*)$$ For an ideal gas: $$dU = \frac{3}{2}nkdT$$ Plugging that into (*) and also from ##p=\frac{nRT}{V}## we get: $$S = \frac{3}{2}nk \int^{T_2}_{T_1} \frac{1}{T}dT +...
  42. abnerko1973

    What is the standard process of Microphone testing?

    Hello. Microphone is a simple device and its mechanism is also simple. The device converting sound waves into electrical energy is mic. But I am little curious about how microphone manufacturer company check their mics before selling? Means Can I test my mic at home using standard process? I...
  43. G

    Change in entropy of an irreversible adiabatic process

    I have been able to get everything except entropy. I know it's not zero. I know I have to find a reversible path to calculate it, but keep coming up with strange values so I don't think I'm doing it correctly. can I do CpdT/T + CvdT/T = ds? I am having trouble calculating my P2 (I know my final...
  44. D

    Java Read a csv file and process the data

    public static Region fromFile(String name, String file) { Region r = new Region(name); List<String> lines = readData(file); String[] headers = lines.remove(0).split(";"); Map<String, Integer> h2i = new HashMap<>(); for (int i=0; i<headers.length...
  45. H

    Biology The process catalyzed by the bacteriophage λ integrase

    Why are the steps catalyzed by the bacteriophage λ integrase successive tranesterifications? How are (A), (B) ,(D) wrong?
  46. baby_1

    A Summation simpilification process

    Hello, Here is my summation: sum(1/(25+n*B)),n=0 to (N/2)-1:=A where A is between .01 to 2, N is between 10 to 2000 and I need to find the B for different values of N. I calculate this summation online (check here) But the Digamma function makes the output function complex and it is not easy to...
  47. Another

    Problem involving an adiabatic process

    in this textbook : http://www.fulviofrisone.com/attachments/article/486/Huang,%20Kerson%20-%201987%20-%20Statistical%20Mechanics%202Ed%20(Wiley)(T)(506S).pdf ;page 20 I don't understand about Eq 1.11 come to 1.12 ? I know dU = U_V dT + U_T dV dQ = dU + p dV put dU into dQ. So dQ = U_V dT...
  48. R

    I Irreversible Isochoric Process in a Cycle

    Consider a reversible ideal gas cycle consisting of: 1. An isochoric heat addition, 2. An isothermal expansion to the initial pressure, and 3. An isobaric compression to the initial volume. What, if any, is the difference in net work done by the gas in the cycle if the isochoric heat addition...