What is Process: Definition and 1000 Discussions

Old topic: https://www.physicsforums.com/showthread.php?t=194725 I have a question that's the same as the one in the old topic/thread I linked to above. At the last post, I am trying to figure out how to carry out the induction process. \sum_{j=1}^n (-1)^{i+j} a_{ij} det(\alpha A_{ij})...

Homework Statement I am just curious whether or not there is a step-by-step algorithm that will always produce the desired results when solving BJT circuits? We are learning them in my electronics course at the moment, and it seems as though the approach to the problems is never...

Hi everyone, My data consists of road accidents and spatial covariates. Originally i wanted to apply an inhomogenous Poisson process with covariates. Then I realized that the accidents cannot occur everywhere in space, but only on roads. I found an example, that is quite similar to mine. it...

Homework Statement Air with the mass of 10kg, with pressure 15 bar and temperature 50 C comes to a isobaric expansion to 3 times the original volume, then the air cools to the pressure of 6 bar(isovolumetricly). After that it comes to adiabatic expansion to original temperature (50 C i guess)...

I have seen a reversible process defined as one in which the system and surroundings are restored to their initial state without change elsewhere. As far as I am aware, the system and the surroundings completely occupy the universe. So, I am failing to understand what elsewhere means in this...

Hi, An amount of ideal gas undergoes the folowing cycle process in the following graph: This process can be presented by the following PV-graph : The answer has to be the upper graph but why can't it be the lower graph ? Thank you!

Homework Statement I have a diagram of a process of a monoatomic gas. and the problem is that I know that the total amount of work = total amount of heat, so there is no internal energy change. why? because my process started at the same temp that it finished. how ever... it is asking me...

how could the process of the kidney's process of reabsorpting the water be simulated through a man made experiment?

Hi, In deriving the equation for adiabats : V^{\gamma}P = C. It is assumed that the work done during the process is W = -P \Delta V. But calculating the work done from V^{\gamma}P = C we obtain: W = \frac{C}{1-\gamma}\left[ V^{1-\gamma}_{f} - V^{1-\gamma}_{i} \right] . Also, i believe to...

I am reviewing material for my thermodynamics class and one of the practice exams says that the change in enthalpy during an isothermal process is equal to zero. This doesn't make any sense to be considering.. \Delta H = \Delta U + PV and since this is an isothermal process.. \Delta U =...

Hey All, Can someone please explain to me the difference between a Poisson Process and a Renewal Process ? is it just that the Holding times for Poisson processes are exponential and Holding times for Renewal Processes are any kind of probability distribution (as the wiki page seems to imply)...

Suppose we have two Gaussian distributions with means A and B. These systems have probability P at time T to be located at X. These are the probability distributions of a simple one-dimensional Wiener process. M=mean P(M,T)=1/sqrt(2*pi*T) * exp(-(X-M)^2/(2*T)) So: P(A...

I was recently invited to be flown to one of the graduate physics programs that I applied to, to be interviewed for a fellowship award (acceptance pending and likely depending on this). I'm fairly excited about this, although I'd like to know what my chances are of being accepted into the...

hello, today I faced a problem with explaining why in anaerobic process the volume of UASB reactor is smaller than volume in CSTR with the same amount of final product - biogas Answer should contain characteristics like: difference in kinetics, concentration, rxn yield. Can anybody explain...

Supercooled water freezes. Is this a spontaneous process?? Homework Statement "one mole of supercooled water at -10degC freezes reversibly to ice at -10degC at constant P of 1500atm. The system is at chemical equilibrium. Assume that ΔH_fusion is independent of temperature. Also assume that...

What is the main different within them process ? Any good web or source can gain more knowledge about them?

Hi, Do anyone know where to get free process simulation software, please, if you know let me know, thanks.

When an electron and a positron annihilate, they typically produce two gamma rays, each of energy mc^2 plus whatever kinetic energy available before annihilation. I was recently told that it is an experimental fact that the electrostatic energy between the electron and the positron does NOT...

Homework Statement Suppose 15.2 g of oxygen (O2) is heated at constant atmospheric pressure from 13.3°C to 148°C. (a) How many moles of oxygen are present? (Take the molar mass of oxygen to be 32.0 g/mol) (b) How much energy is transferred to the oxygen as heat? (The molecules rotate but do...

i can't seem to get something in classical thermodynamics entropy is a state function of a system,that means it only depends on the state of a system not time or path. if i have an irreversible process between state 1 and state 2, and back to state 1, and i want to know the entropy change of...

This is not a homework question. I know the answer to this question I'm just not sure how, from reading the question, I would have known what the question is actually asking. If someone could explain what their thought process is after reading the question, and how it is that you know what the...

Homework Statement One mole of an ideal monatomic gas is taken through the cycle ABCA shown schematically in the diagram. State A has volume 0.0208 m3 and pressure 1.22 × 10 5 Pa, and state C has volume 0.0524 m3 Process CA lies along the 305 ±1 K isotherm. The molar heat capacities for...

Homework Statement A cylinder, A, containing a monatomic ideal gas, is fitted with a frictionless leakfree piston. The axis of the cylinder is oriented vertically, as in the figure below, so that the weight of the piston maintains the gas at a constant pressure P0. The cylinder is linked...

What is the concept behind 'irreversible adiabatic process' ? Why is the expression for work done in this case different from that when it is reversible?

Homework Statement The total population size is N = 5, of which some are diseased and the rest are healthy. During any single period of time, two people are selected at random from the population and assumed to interact. The selection is such that an encounter between any pair of individuals...

This morning, I was lying on my bed, looking at the bright morning light coming in through the window. The blinds (which are white) were at least half shut, so much of the light was filtered through them. I then stared up at the ceiling, and saw a nebulous patch of green. I shut my eyes, and...

Hi, Radioactive materials will decay to datughter products. in the mean process they emit alpha or beta particles with some energy and then decay to new products. In my problem i am just observing U(238) decay process. I need to find the energy values for each decay and also i need...

Just out of curiosity, is there any quasi-static process that is completely reversible? I think the answer is an obvious no because any quasi-static process experiences a net energy loss but I'd like to know if there are any, possibly something abstract rather then mechanical.

when we have light reflecting off a material, what's going on there? is it something analogous to a gas particle rebounding off a container wall due to Coulomb repulsion? If so, what is it that exerts a force to reverse the photon's momentum perpendicular to the surface it's reflecting off...

Hi all, Sorry if this post is a bit wordy but I've been going round in circles and I thought I'd see if anyone on here can help, it's also my first post so be nice... I've been trying to understand how Newton miscalculated the speed of sound. I know that he thought that the propagation of...

Homework Statement The titleHomework Equations ?The Attempt at a Solution The only ways I know of to calculate heat are dQ = Cp.dT and dQ = Cv.dT for isochoric and isobaric process how would you go about doing it for an isothermal process Also if a system isn't a cycle but it ends up in the...

How could you ensure that an electric battery produced an electric current reversibly? How could you achieve maximum work from an electric battery? I really have no idea how to solve this. Thanks for your help! (Also sorry I first posted this in advanced physics...i don't know how to...

Hi I need help to understand Feynman rules for decay for exams. In past paper there is the following question as whether the following are allowed. cc decays to tau++tau-. From What I can see this is possible via the strong force is this correct? The next is cc decays to cu and cu. From...

Homework Statement The Langevin equation for the Ornstein-Uhlenbeck process is \dot{x} = -\kappa x(t) + \eta (t) where the noise \eta has azero mean and variance <\eta (t)\eta (t')> = 2D(t-t')\delta with D \equiv kT/M\gamma. Assume the process was started at t0 = - \infty. Using...

Homework Statement An ideal diatomic gas at 75 K is adiabatically compressed to 40% its original volume. What is its final temperature? Homework Equations delta U = Q - W W = the integral of PdV PVgamma = constant U = 5/2nKT = 5/2nRT (diatomic, ideal gas) The Attempt at a Solution...

I was given the following question Which of the reactions on the right are allowed by first-order processes? For those which are not allowed, state one conservation law which is violated. What is a first order process in particle physics? i.e what does first order refer to? What would be...

What exactly is a process corner. Is it actually the corner on the silicon wafer? Why does speed vary in process corners? Is the doping not uniform?

Homework Statement A vertical piston-cylinder device initially contains 0.2m^3 of air at 20C. The mass of the piston is such that it maintains a constant pressure of 300kPa inside. Now a valve connected to the cylinder is opened, and air is allowed to escape until the volume inside the...

Homework Statement how can I calculate specific heat at constant pressure from mass specific heat and mole mass?

Homework Statement a container with air (M = 29 g/mol, treated as an ideal gas). In the container, we have 2.0 L of the gas with p1 = 1.0 atm at T1 = – 50C. The gas is compressed adiabatically to a final volume of 0.5 L. What is its final pressure? Homework Equations I am really not...

Can anyone help me with understanding what is going on at page 11 of these notes? http://www.chem.utoronto.ca/coursenotes/CHM223/Section%205B%20Fall%202010.pdf Do you get why there is 2 delta Gs? I am really confused with what he was trying to do there? ΔG(37oC) – ΔG(25oC) ≈ – (T – 298)...

My textbook tries to prove that for Entropy of Irreversible Process > 0 by using the example of irrev expasion into a vacuum which doesn't make sense to me. If work is = 0 then no heat is exchanged between the sys and surrounding so qsurr = 0 s(uni) = s(sys) + 0 since S(sys)=qirr/t and no...

Homework Statement One cylinder in the diesel engine of a truck has an initial volume of 600 cm^3. Air is admitted to the cylinder at 35 C and a pressure of 1.0 atm. The piston rod then does 500 J of work to rapidly compress the air. What is the final temperature and volume? I found the final...

Hello, As part of my final year project I am to run a CFD analysis of a pump impeller. I have been provided with the impeller and diffuser CAD models and successfully imported these into gambit. However, after completing a number of the gambit tutorials I still have no experience in meshing...

hi, DNA and RNA seem to be very peculiar molecular structures that are able to replicate themselves, and they are unique regarding this point, right?. But which chemical "magical" phenomena is responsible for this ability to reproduce?

Hi guys I have produced an ingot of NiTiHf alloy through Vacuum Induction Melting (VIM) process and by using pure materials of Ni, Ti and Hf. Casting was done in a Y2O3-coated steel mold, and the crucible was made of graphite. The problem is that, when I homogenize the ingot at 1000 oC and...

Hi there Can someone teach me how a L2M2M3 Auger process looks like? I appreciate every kind of help.

Pressure and velocity changes with temperature in open flow tube Hello everyone, I have a process in which a gas goes through a heater. I want to calculate the physical properties of the stream coming out of the heater. Here is a description of the streams: Input to the heater: molar...

Hi guys, For today's lunchtime challenge... If I put 1kw of electrical energy into a heating element and get X amount of heat out, why can't I put ~X amount of heat into the element and get ~1kw of electricity out? ( I accept less than 100% reverse process ability) what's the mechanism...

pls i need help on this one... i would like to know how gear profiles are specified