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:

View More On Wikipedia.org
  1. S

    I S-Channel Process: a+b->c+d Diagrams

    Hello I encountered a problem in which it is specify that there are 2 time-ordered diagram for the s-channel for a certain process a+b->c+d. I understand that there is the one that can be associated with annihilation, but what would be a second one? Thank you!
  2. Avi Nandi

    A Stochastic Differential equation: Dichotomous Process

    I am studying a dichotomous markov process. The master equation is given in this link https://en.wikipedia.org/wiki/Telegraph_process. I want to calculate the mean and correlation function given also in the link. But actually I can't make any progress. How from this master equation governing the...
  3. joe_cool2

    Linear Algebra - Gram-Schmidt Process

    Homework Statement Let R2 have the Euclidean inner product and use the Gram-Schmidt process to transform the basis {u1,u2} into an orthonormal basis. u1 = (1,-3) u2 = (2,2) Homework Equations Gram-Schmidt process: \\v_1 = u_1 \\v_2= u_2 - \frac{\left ( \left \langle u_2, v_1\right \rangle...
  4. O

    A Black Hole Paper Outlining Process of Singularity Formation

    Can someone point me to the seminal (or any other) paper explicitly showing and proving the formation of singularities in black holes? I'd like to learn about the exact physical processes which occur during the collapse of a star into a black hole and how the progress of those physical...
  5. Arubi Bushlee

    What is the process of invention?

    I make no promises: I came up with this idea for a new kind of nuclear fusion reactor. I do not want to give off any clues to how it works so I am going to be as vague as possible. I think it could be a viable means to nuclear fusion becoming... well, breakeven. I have by no means tested it...
  6. Z

    Thermodynamics: Irreversible process and entropy

    Homework Statement Hi ! I'm stuck with these two questions of my assignment of thermodynamics - Give two exemples of irreversible process (initial state, process, final state) - For each of them, explain why they are irreversible on the microscopic scale. Homework Equations We are not asked...
  7. John Pang

    B Struggle to understand adiabatic process

    I find really confused about the adiabatic process. According to my textbook, adiabatic process is a process in which no heat is allowed to flow into or out of a system. According to the first law of thermodynamics, change in internal energy=heat added to system- work done by system,so change...
  8. T

    Steady State Distillation Process

    A steady state distillation process is shown diagrammatically as FIGURE 1. Assuming no heat losses to the atmosphere: (i) Write four balanced equations for this system. (ii) Identify where any constitutive equations may be required for the modelling processes.There are two states that I can...
  9. S

    Is Dropping a Metal Block into a Lake a Reversible Process in Thermodynamics?

    Hello all. I have a quick question about entropy... I've just been formally introduced to it. Consider the example of a metal block of mass m and heat capacity Cp at temperature T1 = 60C being dropped into a large lake of temperature T2 = 10C. $$\Delta S_{block} =...
  10. R

    Things that can influence an oxidisation degradation process?

    Hopefully I can get away with not describing the mechanics of the process. In general, if there is degradation of a solution via oxidisation, the process is not always purely oxidising, there can be other factors at work i.e. degradation may cause the solution to become hydrophobic and change...
  11. naima

    A Is measurement a yes/no process?

    the wave/particle duality is no more seen as the opposite sides of a coin. We now see it as a point in a segment [0 , 1]. It is the same with pure states. The visibility of the fringes varies between 0 and 1. In regards to measurement, We are often in the old yes/no habit: At a some point the...
  12. Jeremy1789

    Adiabatic Process, Internal Energy vs. Enthelpy.

    I'm struggling to understand a concept which I assume is basic, but I can't seem to fit the pieces together. When speaking about an ideal gas, I understand that ΔH = ΔU + Δ(PV) = ΔU + RΔT So far so good. I also understand the relationship: ΔU = Q + W... (W here is work being done on the...
  13. S

    Entropy change in a reversible isothermal process

    Why does ∆S = 0 for a reversible process, but for a reversible isothermal process, ∆S is given by nRln(Vf/Vi) (or other variations of that equation)?
  14. A

    Reversible vs irreversible work for adiabatic process

    I have a gas transitioning adiabatically between A (P1, V1) and B (P2, V2) where P1>P2 and V2>V1. The question is to determine the net work done on the gas if the gas is first expanded reversibly from A to B (w = dE = Cv(T2-T1)), and then compressed irreversibly from B to A (w = -Pext(V1-V2)) at...
  15. Ali Durrani

    Force required for cutting process

    hello brothers and sisters, i have got a project on making an agriculture shredder, i am having difficulty in finding the general equation for the force required to perform cutting operation can anyone help me out
  16. Planobilly

    Need Some Guidance For Testing Process On Vacuum Tube Amp

    Hi Guys, I am having issues trying to repair this amp. http://www.tangible-technology.com/schematics/fender/HR-Deville/Hot%20Rod%20DeVille.pdf A little history is in order I guess. I have not been working on guitar amps for too long, several months now. I have repaired perhaps fifty or so...
  17. J

    How Do You Calculate the Polytropic Process Index 'n' in Thermodynamics?

    Homework Statement "Determine the polytropic process index 'n' from the initial and final condition parameters of the air (gas) in the air compressor cylinder." Im struggling with this question on my thermodynamics coursework and was wondering if anyone could help me out a little bit...
  18. O

    Irreversible adiabatic process - is the entropy change zero?

    Homework Statement A well insulated container consists of two equal volumes separated by a partition - one half an ideal gas while the other is a vacuum. The partition is removed, and the gas expands. What is the entropy change per mole? Homework Equations dS = dQrev/T S/R = Cp/R dT/T -...
  19. K

    Thermodynamic properties - Isochronic process - First law

    Homework Statement An amount of water substance having a mass of 1 kg is contained in a vessel at a pressure of 1 MPa. It is heated for some time after which the pressure is 3 MPa. The volume of the vessel is 0.1 m3. Assuming no work is done by or to the substance, calculate the final...
  20. A

    Solving Sieve Process Problems: 50% Done, Graph Help Needed

    I have sieve process problem. I alreday solved 50% like Xcut-off but I do not know how the graph is drawn from the table?
  21. J

    The internal energy in isobaric process

    1. Homework Statement When volume changes from V to 2V at constant pressure then the change in internal enrgy will be? 2. Homework Equations ΔU= nCvΔT 3. The Attempt at a Solution I have used the equation ΔU= nCvΔT but the answer is PV/γ-1
  22. J

    Random process involving CDF and PDF of standard normal

    Homework Statement Let $$ \Phi(x)=\int_{-\infty}^{x} \frac{1} { \sqrt{2\pi} } e^{-y^2 /2} dy $$ and $$ \phi(x)=\Phi^\prime(x)=\frac{1} { \sqrt{2\pi} } e^{-x^2 /2} $$ be the standard normal (zero - mean and unit variance) cummulative probability distribution function and the standard normal...
  23. J

    Autocorrelation function of a Wiener process & Poisson process

    Homework Statement 3. The Attempt at a Solution [/B] ***************************************** Can anyone possibly explain step 3 and 4 in this solution?
  24. S

    Microspectrophotometers -- manufacturing process

    Hello! Can someone please help me with finding a full explanation on the production (manufacture) process of microspectrophotometers? I need to do a presentation on microspectrophotometers and I have a problem with finding this information. Thanks!
  25. Z

    The definition of transverse amplitude in the process: ep→epπ

    When CLAS of Jlab describe the result of the process ep→epπ,the use the terminal "transverse amplitude" Ml±(W,Q2), El±(W,Q2),and "scalar(longitudinal) amplitudes"Sl±(W,Q2),they correspond to photons of the magnetic, electric, and Coulombic type.Are they observables? The index of...
  26. J

    Birth and death process -- Total time spent in state i

    Homework Statement Let X(t) be a birth-death process with parameters $$\lambda_n = \lambda > 0 , \mu_n = \mu > 0,$$ where $$\lambda > \mu , X(0) = 0$$ Show that the total time T_i spent in state i is $$exp(\lambda−\mu)-distributed$$ 3. Solution I have a hard time understanding this...
  27. J

    Understanding the Characteristic Function in Solving Poisson Process Problems

    Homework Statement Insects land in the soup in the manner of a Poisson process with intensity lambda. Insects are green with probability p, independent of the color of the other insects. Show that the arrival of green insects is a Poisson process with intensity p*lambda. Homework Equations3...
  28. Luis Obis

    Isobaric process for a Van der Waals gas

    Homework Statement [/B] You are asked to calculate changes in internal energy, entropy, heat transferred and work done for each of the following process. Also you are asked to calculate "the latent heat for the isotherm in the figure". We know the a and b parameters which characterize the VdW...
  29. SSGD

    Time Distribution Histogram for a process with two peaks

    I have been studying a processing time for an industrial process. The present analysis just consists of finding the mean value as if the time was distributed normally. I took a sample of data and made a histogram of the data and realized it is not normally distributed at all. The normal...
  30. P

    Throttling Strategy for Steam Process

    ohk, let me make it more clear for you, the situation is we have a boiler generating steam at 23.5 barg, which is throtlled down to 12 barg for import/ export, this 23.5 barg steam is throttled down to 3 barg by another valve to use in heat exchanger, and then this 23.5 barg steam is throttled...
  31. C

    Heat Rejection process of Carnot Refrigeration

    Hi there, I just sign up today. I'm curious to know about the energy added/released in a Carnot Refrigeration Cycle. Let's say the problem is like this: A Carnot Refrigerator used refrigerant-134a as the working fluid. During the heat addition process, a percentage of mass of the refrigerant...
  32. vetgirl1990

    Entropy change of calorimetric process

    Homework Statement A 20 kg sample of mercury is completely solidified and liberates 231.6 kJ of energy. What is the original temperature of the mercury? (The melting point of mercury is 234K, the heat of fusion of mercury is 11.3 kJ/kg, and the specific heat of mercury is 140 J/kg•K.) . What is...
  33. Pouyan

    How do temperature differences affect the work done in an ideal Carnot process?

    Homework Statement An ideal Carnot process operates between a heating bath with the temperature of 20 C and a mole of hydrogen is in a container with constant volume. During the process, the work is done to remove heat from the hydrogen gas and emit heat to the heat bath. Calculate the work...
  34. Stephanus

    Composting Process: Learn About Oxygen, Carbon, Hydrogen & Nitrogen

    Dear PF Forum, My church concerns about climate change/global warming condition now. And we try our best to cope (altough in a very small scale) to lessen the effect. Now, I'd like to know about composting. But I have no idea what to do. What stages are there in composting What kind of bacterias...
  35. A

    Calculating entropy generation of a process

    Lets say we have T1. From a reservoir 4000K, Q is added and that makes the temperature T2. How do we calculate the entropy generation in a process like that? Isn't it Sgen=S2 - S1 - (Q/T) But which temperature we will use in the (Q/T)? T1, T2 or 4000K?
  36. D

    Exploring the Expectation of a Random Process with Unequal Probabilities

    Hello, So I was asked this question the other day and don't really know how to go about it: "Define a random process by: Xn+1 = Xn+1 with probability 1/2 Xn+1 = 1/Xn with probability 1/2 Given that X0= 100, find the expectation of X10 " I've only ever really met random processes...
  37. M

    Amplitude of a process + interference term, how what?

    Hello guys, Suppose a process 1+2--->3+4 proceeds thru 3 different intermediate particles and has 3 Feynman diagrams. When we compute the probability then what does the cross terms( interference ) mean? and do we have to always compute the cross terms? What I mean is that when you have 3...
  38. H

    The change in entropy in adiabatic process

    Hello everyone, I still wonder if there's a change in entropy in adiabatic process. The definition of entropy is a quantity represents for the disorder state of a system. Arccording to kinetic theory of gas, temperature is for the state of chaotic motion of molecules. So I'm very confuse, can...
  39. S

    How throttling is a steady flow process?

    If throttling reduces mass flow rate then how can we say it as steady flow process where the mass flow rate is constant?
  40. N

    Process for solving integration problems

    . Homework Statement Q1. Let f(x) be any continuous function that satisfies: $$-2x≤xg(x)≤2x$$ for $$0≤x≤1$$ Find the upper and lower bounds for: $$\int_{0}^{1} \sqrt{1+g(x)+x^2}dx$$ Q2. Let h(x) be any continuous function that satisfies: $$-4≤h(x)≤x^2-4$$ for $$0≤x≤1$$ Find the upper and...
  41. C

    Basic thermodynamics, reversible engine process

    Homework Statement http://i.imgur.com/jmLqca9.jpg pic of question Homework Equations W = p x dV, Q = dU + W etc The Attempt at a Solution I know what the different stages are, a-b and c-d are isobaric, d-a and b-c are isochoric and I believe the answer to a, the net work done in one cycle...
  42. E

    MATLAB Image Processing and MatLab (Deconvolution Process)

    I have these two images: And I have this impulse response function, or the point-spread function (PSF): The first image is the actual size of the PSF, and the second image has zero pads included. I tried deconvolving the images this way (with MatLab): deconvolved_image =...
  43. H

    Why Use Nitric Acid for Heavy Metal Digestion?

    I already done an experiment for detecting the presence of heavy metals(copper and lead) . The last step for detection is through the absorption of analyte by atomic absorption spectroscopy. Before that step to be done, the first process is to digest the water sample in the fume chamber...
  44. M

    Gauss-Markov process covariance function

    Hi all. I've been getting up to speed with Gaussian processes (https://en.wikipedia.org/wiki/Gaussian_process), and was interested to know what properties a Gaussian process must satisfy for it to also be a Markov process (https://en.wikipedia.org/wiki/Markov_process). Briefly, a Gaussian...
  45. G

    Continuous process and equilibrium constant.

    Assuming that we have a chemical plant which produces methanol through the following equations: CH4 + H2O <--> CO + 3H2 CO + 2H2 <--> CH3OH CO2 + 3H2 <--> CH3OH + H2O I know that with specific pressure, temperature and flow rates, I can produce reactions with specific equilibrium constants. Are...
  46. L

    Why is the Definition of Entropy Restricted to a Reversible Process?

    Even though entropy is a state function and thus independent of path why is it that the definition of entropy is restricted to a reversible process? Eq 1: dS=dqrev/T First of all, is this for an open system, closed system or isolated system? The Clausius inequality deals with the exchange...
  47. C

    Independent Process Probability distribution

    A manufacturer has designed a process to produce pipes that are 10 feet long. The distribution of the pipe length, however, is actually Uniform on the interval 10 feet to 10.57 feet. Assume that the lengths of individual pipes produced by the process are independent. Let X and Y represent the...
  48. F

    Calculating work done on parcel given a specific process?

    Homework Statement Problem: A sample of dry air has an initial pressure p1 = 1000 hPa and temperature T1 = 300K. It undergoes a process that takes it to a new pressure p2 = 500 hPa with unchanged temperature T2 = T1. Compute the mechanical work per unit mass perfromed by the sample under the...
  49. F

    Time Series - Autoregressive process and Probability Limit

    Homework Statement Calculate: PLIM (probability limit) \frac{1}{T} \sum^T_{t=2} u^2_t Y^2_{t-1} Homework Equations Y_t = \rho Y_{t-1} + u_t, t=1,...T, |\rho| <1 which the autoregressive process of order 1 E(u_t) = 0, Var(u_t) = \sigma^2 for t cov(u_j, u_s) = 0 for j \neq s The Attempt...
  50. O

    How is isobaric process physically possible?

    We have an ideal gas enclosed in cylinder whose top is covered by a piston of certain weight ##mg##. At this stage, the piston is at rest which means the force by which the gas acts on the piston (##F=PA## where ## P## is the gas pressure and ##A## is the cross sectional area of the cylinder) is...
Back
Top