Process Definition and 1000 Threads

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. S

    I Energy Level Change in Adiabatic Reversible Process

    Hello, I am currently trying to get my head around the concept of entropy. One way to understand it is that it can be related to the amount of available energy levels in a system. From what I read, the availability of energy levels in a system: 1) increase with an increase in the system...
  2. fullmetal_alchemist

    How Pyrolysis works (step by step process). Need help

    I've just looked through different kinds of sites and I can't seem to find any specific answers. I need it for our technical report. If you guys know any links, just quote it here. I just really need your help
  3. HethensEnd25

    What is enthelpy for an adiabatic process

    I have a question I hope someone may be able to answer. I am currently working out an adiabatic compression process that gives me an initial pressure,volume, and temperature. Along with a final pressure and given that the cylinder/piston assembly does not conduct any heat. Another given is that...
  4. P

    Charging a capacitor with a battery

    How does it work? I mean I know all the stuff, there is difference in potential and the charges flows, my question is, does the negative terminal of the batteries suck charges or the charges flowing to the negative terminal are flowing because they are pushed by the charges induced on the plate...
  5. Mr Davis 97

    B Logical process of solving equations

    I read that in solving an equation, the reault is only a possibility for a solution, and not necessarily a solution. For example, in solving x+3 = 5, x=2 is not a solution until you explicitly plug it back into show that it actually. Why is the statement x=2 not enough to show that 2 is actually...
  6. Ian Baughman

    Thermodynamic Process: Is Work Conserved?

    What is wrong with this logic, if any? It does not seem like this should be true but maybe I'm mistaken. Assuming the process consists of two isobaric processes and two isothermal processes the work from B to C in terms of p1, p2, V1, and V2 is given by the following. 1) WBC=p2(VC-VB) 2)...
  7. RMalt

    Isobaric and Isochoric Process Combined

    Homework Statement [/B] This is a very basic question. I have a cylinder filled with air having stops at a particular height . First part of the process is isobaric as piston is free to move and P is constant. When piston reaches stops this becomes isochoric process as volume is constant. So...
  8. S

    Calculating Mass Flow Rate of Steam

    Homework Statement If 5% of the heat available for steam production is lost to the atmosphere, determine the amount of steam raised per hour when the total flow of flue gases is 1400 kmol h-1. qmH = 1400 kmol h-1 Flue gas temperatures: Inlet = 1832°C Outlet = 300°C Water temperature: Inlet...
  9. nomadreid

    I Odd use of terms (“stationary stochastic process”., etc.)

    I am trying to make sense of a Russian author’s use of terms (I have to translate his article). I have three questions, but please don't think you need to answer all three before answering. Thanks for any insights! [1] He uses the term “probability density distribution” ρ(ξ) of a stationary...
  10. I

    How did our genetic process get set up?

    In bio we are learning about genetics; DNA replication, transcription and translation. The process from DNA to proteins is extremely, extremely complex (not understanding it, just the mechanics of it). It just seems like a weird thing to come up naturally. Now, I am not a believer in inteligant...
  11. S

    I Is the decay of a muon always a 1 to n process?

    Decay processes are quite common in particle physics. Is the decay process always a ##1 \rightarrow n## process? In other words, can we call the reaction $$\mu^{-} + \mu^{+} \rightarrow \phi,$$ where ##\phi## is some scalar particle, the decay of the muon?
  12. S

    A Possible decay process for a cubic scalar self-interaction

    Consider the Lagrangian $$\mathcal{L}=\frac{1}{2}\partial_{\mu}h\partial^{\mu}h-\frac{1}{2}m^{2}h^{2}-\frac{\lambda}{3!}h^{3}$$ for a real scalar field ##h##. This is the Klein-Gordon Lagrangian with a cubic self-interaction term. Does this model allow the decay process $$h \rightarrow h +...
  13. S

    A What are the different decay processes shown in this Feynman diagram?

    Consider the following momentum-space Feynman diagram https://upload.wikimedia.org/wikipedia/commons/b/b5/Lepton-interaction-vertex-eeg.svg This Feynman diagram is the leading-order contribution to the any of the following processes: 1. ##e^{-} \rightarrow e^{+} + \gamma## 2. ##e^{+}...
  14. R

    Is enthelpy change during isothermal process zero?

    is enthalpy change during isothermal process zero? if it is zero then what is the significance of enthalpies like enthalpy of vapourization or fussion since during phase transformation temperature remains constant.
  15. H

    Open question - How do you mentally process commands/data when coding....

    I'll start off by saying that this isn't really a question about how to code, but about how you code personally. If there's a more appropriate forum for me to post in just let me know! A little exposition: I'm an illustration/ISTA major doing a project for a class that requires interviewing...
  16. S

    A Adiabatic process - quantum mechanics and thermodynamics

    A diabatic process is defined as follows: Rapidly changing conditions prevent the system from adapting its configuration during the process, hence the spatial probability density remains unchanged. Typically there is no eigenstate of the final Hamiltonian with the same functional form as the...
  17. P

    Finding the Minimum Work Done for a Thermodynamic Process

    Homework Statement Given two indistinguishable objects at the same initial temperature ##T_i##, calculate the minimum work done by a refrigerator functioning between the two objects till one of the objects reaches a new temperature ##T_2##, assume constant heat capacities and constant pressure...
  18. S

    A Penrose Process & Hawking Area Theorem Explained

    Hawking area theorem says that area of black hole generally never decrease. Penrose process says that energy can be extracted from black hole. Energy extraction will decrease mass? if yes then if mass is decreased then will area also decrease? I am confusing things here :(
  19. A

    Thermodynamic process: freezing

    Homework Statement A 0.350 kg sample is placed in a cooling apparatus that removes energy as heat at a constant rate. The figure below gives the temperature T of the sample versus time t; the horizontal scale is set by Ts = 80.0 min. The sample freezes during the energy removal. The specific...
  20. A

    ΔU, Q, W of thermodynamic process

    Homework Statement A monatomic ideal gas undergoes the thermodynamic process shown in the PV diagram. Determine whether each of the values ΔU, Q, and W for the gas is positive, negative, or zero. Homework Equations ΔU=Q-W W=integral under the curve PV=nRT T=PV/nR The Attempt at a Solution...
  21. I

    Adiabatic Process: Work Calculation for Ideal Gas

    Homework Statement A turbine is driven by compressed air. The air enter the turbine with temperature ##T_1## and pressure ##P_1##. When the air leaves the turbine it's pressure is lowered to ##P_2##. Calculate the work done for one mol air. The expansion of the air can be seen as reversible...
  22. Brian Curtis

    Why Is There Disagreement on Entropy in Irreversible Adiabatic Processes?

    Why does there tend to be disagreement on an irreversible adiabat entropy determination? Doesn't an irreversible adiabatic expansion increase the entropy of a system by the Clausius inequality?
  23. N

    MHB Why Are My Gram-Schmidt Results Different on Wolfram|Alpha and MATLAB?

    Wolframalpha provides this solution: Wolfram|Alpha: Computational Knowledge EngineHowever when i compute the second term v2 = x2 - (x2.v1)/(v1.v1) * v1 The result is different from that of above. What's wrong? Wolfram|Alpha: Computational Knowledge Engine)
  24. arpon

    How Does the Van der Waals Equation Define Adiabatic Processes for Real Gases?

    Homework Statement Show that for a gas obeying the van der Waals equation ##\left(P+\frac{a}{v^2}\right)(v-b)=RT##, with ##c_v## a function of ##T## only, an equation for an adiabatic process is $$T(v-b)^{R/c_v}=constant$$ Homework Equations ##TdS=c_vdT+T\left(\frac{\partial P}{\partial...
  25. mertcan

    I N events occur in one Poisson process before m events

    guys, I have a very ımportant question. First let me introduce parameters: $$S^A_1 = \text{first arrival of A event}, and S^B_1= \text{first arrival of B event}, and S^C_1=\text{ first arrival of C event}$$, then probability of $$P(S^A_1<S^B_1) = \frac {\lambda_A} {\{ \lambda_A + \lambda_B \}...
  26. E

    Induction Heating Process Characterization

    Hi All, I'm working on a process involving induction heating. I'm heating up an irregular shape ss die to make a bond. My dilemma is in my understanding of where the eddy currents will be that generate the heat (based on skin effect). The clam shell die is pictured below. The right hand...
  27. A

    Process of energy transfer&mass in inflating tyre

    Homework Statement Inflate the tyre from 10 psig to 30 psig. Explain the process of mass and energy transfer in inflating tyre Homework Equations No equation The Attempt at a Solution I think there is no energy transfer on it process and there is only mass transfer. But i read some article...
  28. S

    Change in the internal energy of an isobaric process

    Homework Statement A cylinder contains 0.250mol of carbon dioxide (CO2) gas at a temperature of 27.0∘C. The cylinder is provided with a frictionless piston, which maintains a constant pressure of 1.00atm on the gas. The gas is heated until its temperature increases to 127.0∘C. Assume that the...
  29. S

    Energy change of reservoir in reversible weight process

    In what follows I refer to the ideas of "Thermodynamic: Foundations and Applications" by Gyftoploulos and Beretta. The abbreviated form of my question is: In a reversible weight process, Ω1R-Ω2R = E1 - E2 (see eqn. 6.18, p. 99) is transferred out of the composite of a system A and a reservoir R...
  30. VoloD

    Job Skills Why is University never considered in the hiring process

    Why do people base a new employees skill set based solely on degree and not the program they attended. For example, engineering is considered to be a marketable field. However, not all engineering programs are created equal. I understand that elite institutions will be preferred over the...
  31. MexChemE

    Types of signals in process control

    Hello, PF! I've been learning some process control on my own lately, and some questions have come to my head while on it. Consider the following on-off control loop: Let's say we want to control the temperature of the fluid inside the tank. We set up an on-off control loop and establish a...
  32. E

    Chemistry Level of statistics required in Process Chemistry and ChemE

    Question: So I hold a Bachelor's degree in Chemistry and have just started a M.S./Ph.D. track in Chemical Engineering. My dream job is in mineral processing (the biggest dream is with an asteroid mining company), but I understand that the school I'm going to is heavily focused on drug discovery...
  33. E

    Entropy Change in a Reversible Process multiple phase change

    Homework Statement (a)How much heat must be added to a block of 0.120kg of frozen ammonia initially at 100oC to convert it to a gas at 80oC given the following information? (b) assuming this could be done using a reversible process what would be the total entropy change associated with this...
  34. B

    Prove irreversibility in this quasi-static process.

    Consider a piston-cylinder arrangement with an ideal gas inside the cylinder. The region outside this arrangement or thermodynamic system is absolute vacuum. The piston has some mass and initially everything is in equilibrium. The inner surface of the cylinder is rough hence friction force comes...
  35. J

    A Russian claim about process for elements transmutation

    What do you think? RU2563511 MICROBIOLOGICAL METHOD OF TRANSMUTATION OF CHEMICAL ELEMENTS AND CONVERSION OF ISOTOPES OF CHEMICAL ELEMENTS Viktor Kurashov, Tamara Sakhno SUBSTANCE: radioactive raw materials containing radioactive chemical elements or their isotopes, are treated with an aqueous...
  36. R

    B Polytropic process with heat addition

    In polytropic process if we know p1,v1,v2 and q(heat added in process) then what will be the value of p2 and the coff. Of expansion (n) ?
  37. mukul

    A Big debate: following process is reversible or not

    There had been a big time debate in my college between chemistry faculties and physics faculties on whether the following process is reversible or not. consider that there is some gas (assuming ideal gas) in a chamber with friction less piston of 5kg and 2 kg mass on top of it as shown in the...
  38. S

    Internal energy in irr. process with molar heat not constant

    I'm a bit confused about the following situation. In a irreversible thermodynamics process the molar heat of an ideal gas changes according to a function of the temperature, say ##c_v=f(T)## (which also leads to ##c_p=R+f(T)##) and I'm asked to determine the heat exchanged during that process...
  39. S

    Work in a process which is both adiabatic and isobaric?

    In a adiabatic process (not necessarily reversible) from ##V_a## to ##V_b## the work can be written as $$W=\frac{p_aV_a-p_bV_b}{\gamma-1}$$ Where ##\gamma= \frac{c_p}{c_v}## Suppose that the adiabatic process in question (again, not necessarily reversible, so ##pV^{\gamma}## can also not be...
  40. S

    Can the work in a isochoric process be non zero?

    I came up with a doubt regarding isochoric irreversible processes. Is it always true that, for any isochoric process, reversible or not, the work exchanged by the system is zero and the heat exchanged is ##Q=\Delta U##? I'm asking this because, in a exercise on thermodynamics trasformations of...
  41. C

    Entropy change of environment during an irreversible process

    What is the change in entropy of thermodynamic environment if it changes its temperature during the process and the process is not reversible? I'm slightly confused because, on the one side, in that case ##\Delta S_{gas} \neq -\Delta S_{surroundings}##, since ##\Delta S_{universe} >0## but on...
  42. Dr. Who

    I Relation between 'P' and 'V' for an Adiabatic process

    Hi All, I have a little query concerning the derivation of PV γ = constant. In my textbook of Physics, first they give the equation for adiabatic process using the first law of Thermodynamics, as; dEint = W → (1) where, ΔEint ⇒ change in internal energy and W ⇒ workdone Then, they used...
  43. E

    A Measuring the degree of convergence of a stochastic process

    Consider a sample consisting of {y1,y2,...,yk} realisations of a random variable Y, and let S(k) denote the variance of the sample as a function of its size; that is S(k)=1/k( ∑ki=1(yi−y¯)2) for y¯=1/k( ∑ki=1 yi) I do not know the distribution of Y, but I do know that S(k) tends to zero as k...
  44. Ravi Singh choudhary

    I Why evaporative cooling is a constant wet bulb temp process?

    Wet bulb temperature is the lowest thermodynamic temperature of air that can be achieved at ambient condition, by creating 100% relative humidity in the immediate surrounding of the thermometer using cotton wick. As Wikipedia says "By contrast, the dew point is the temperature to which the...
  45. A

    A How Does the Penrose Process Allow for Energy Extraction from a Black Hole?

    Hi everyone, I am a bit confused about the Penrose Process. Let's say a particle with energy E at infinity arrives in the ergoregion of a Kerr black hole and then it decays into two photons. One of them has L_1<0 and E_1<0 and hence it falls towards the singularity, while the other has L_2>0...
  46. Luca_Mantani

    A How to determine if 2 particles come from the same process

    Hi, I am studying the Higgs discovery and I've got a doubt. One of the process used to discover Higgs is the decay H -> γγ in 2 photons. At LHC there are detectors of photons that can measure energy and momentum of them. So if you measure the energy and the momentum of both, you can calculate...
  47. B

    Ideal gas through Isobaric process

    Homework Statement This is probably a real easy task for most, but I simply CANNOT manage to calculate it, even given the correct answer. I will translate it as best I can and hope I don't phrase it in a way that causes misunderstandings: 12 Moles of an ideal gas go through an Isobaric...
  48. R

    Process which electricity is generated (Nuclear power)

    Homework Statement I picked a nuclear power plant. I spent a bit of time researching what the basic process is and that's what I've arrived at so far. I'm not certain if the answer is complete/decent, it seems like a very complex process which even for 'point form' could be a page of...
  49. James Ray

    Work done on ideal monatomic gas in adiabatic process

    1. The problem statement, all variables and given/known data Homework Equations [/B] The Attempt at a Solution [/B]
  50. CynicusRex

    I Poisson process approximation error

    X = # of cars that pass in one hour E(X) = λ = n * p λ cars/1hour = 60min/hour * (λ/60) cars/min In this old video (5:09) on poisson process Sal asks: "What if more than one car passes in a minute?" "We call it a success if one car passes in one minute, but even if 5 cars pass, it counts as 1...
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