Process Definition and 1000 Threads

Say we have a cilinder, thermally isolated from the environment, divided in two parts by a piston. In the left part we have an ideal gas, in the right part an unstretched spring. After we set free the piston, in the final phase, we fin that the gas' volume has doubled, while it's temperature is...

I have a problem whereby sludge of quantity 1000 kg/day is required to fill an anaerobic digester tank. The sludge enters at 20deg and is heated to 35deg. With refernece to this link http://books.google.co.uk/books?id=D...obic+digestion it can be seen that if I have a quantity of 1000kg/day...

There is an air bubble at a certain depth and it's rising to the surface of the water. The temperature of the water is constant at a certain temperature. The gas inside the bubble expands as it rises to the surface, but does the temperature of the air stay the same? Is this an isothermal or...

i m rubbish at chemsitry, so can someone explain this process, especially what the final thing would be? Copper sheet > rinsed in a bath of nitric acid > violently oxidized by dipping into a solution of copper sulphate dissolved in sulfuric and hydrochloric acids i read it in a book...on...

Evo asked in another thread https://www.physicsforums.com/showpost.php?p=2079435&postcount=54 The short answer is no. The reviewers are human and subject to human bias. Bias is an intrinsic part of human nature. Scientific reviewers are not immune. The peer review process is not perfect...

Hi I have been learning about the Carnot and Rankine Cycles, where process 4-1 is through a evaporator, process 1-2 a turbine, 2-3 a condensor and 3-4 a compressor. Sketching this on a T-s diagram gives straight horizontal lines for processes 4-1 and 2-3. This is where the heat is extracted...

What are the advantages of having a smaller die fab process on a CPU or GPU? Doesn't it reduce heat production and power consumption?

Hi, While teaching myself Time Series Analysis and ARMA processes in particular, I came across the question, whether two ARMA(p,q) processes \varphi(B)X_t=\theta(B)Z_t \qquad\qquad \tilde \varphi(B)\tilde X_t=\tilde \theta(B)\tilde Z_t\ with different autoregressive and/or moving average...

The following 3 step process refers to a simple RC circuit with a battery and an initially open switch: 1- the switch is closed, allowing the capacitor to charge; 2- after the capacitor has charged, a slab of dielectric material is inserted between the plates of the capacitor and time...

Suppose that one mole of a monatomic perfect gas at 27°C and 1.00 atm pressure is expanded adiabatically (i.e. no heat transfer, so that the temperature must fall) in two different ways: (a) reversibly, to a final pressure of 0.5 atm, and (b) against a constant external pressure of 0.5 atm...

Homework Statement I have 3 vectors. I need to find the ortonormal basis by Gram-Schmidt. The Attempt at a Solution I observed that, without Gram-Schmidt, I get two vectors which I get too by Gram-Schmidt. I have just divided the vectors by their lengths. The third vector got without...

Hi I need to Interview a Computer or Electrical Engineer for an assignment. If somebody could answer the following questions it would be much appreciated. What type of communications do you write ( Proposals, instructions, memos, etc)? What types of readers do you address? What is your...

Homework Statement A cup sitting on the table contains 200g of water. You measure it at a certain time and it is 20 degrees Celsius. You leave the room and come back 10 minutes later. It is now 25 degrees Celsius. What can you conclude about the heat added to the water? [hint trick question]...

Hello, I'm a Process Engineer in an Aluminum Foundry and haven't been able to find the formula to solve the following problem and I'm hoping someone here can help. I've been digging through old textbooks, thinking this should be simple, but w/ no luck. - Thanks in advance. I've got a vessel...

This is probably a difficult question to answer, but if someone could refer me to some books/journals, I would greatly appreciate that.

Homework Statement An adiabatic process is performed on 15 moles of an ideal gas. the initial temperature is 320 K and the initial volume is 0.80m^3. the final volume is 0.40m^3. the adiabatic constant for the gas is 1.44 the heat absorbed by the gas in kJ is closest to a. 0 b.+54 c.-14...

Homework Statement twenty moles of a monatomic ideal gas (lambda=5/3) undergo an adiabatic process the initial pressure is 400kpa and the initial temperature is 450K. The final temperature of the gas is 320K. The heat absorbed by the gas in kJ is closest to? a.0 b.+54 c.+32 d.-54 e.-32...

Suppose that A and B follow geometric brownian motion, where zA, and zB follow wiener process dA/A=a*dt+b*dzA dB/B=c*dt+d*dzB dzA*dzB=e*dt What stochastic process does A/B follow? This is not a homework question(I am sure it's almost trivially easy to those who learned the stuff). I am very...

Homework Statement If you find a mushroom, what is the chance that at least one more will be within one yard from it ? What is the chance that there is exactly one mushroom within the distance one yard from the point you stay? The mushrooms grow in a forest randomly , with density 0.5...

Dear all, I'm trying to implement an Extended Kalman Filter for position, velocity and orientation tracking of a rigid body and I am using quaternions for representing the orientation in the state vector. As this is the first time I have to work with a Kalman Filter, and the project is on a...

A component in a manufacturing process breaks down regulary and needs to be replaced by a new component. Assume that the lifetimes of components are i.i.d. random variables. The company adopts this policy: a component is replaced when it breaks down or after it has operated for time "a"...

Homework Statement During photosynthesis found that a plant is necessary to absorb 8 photons of red light with wavelength 6850 Å to produce an O2 molecule. The average energy storage during photosynthesis is 112 kcal per mole O2. Calculate the energy efficiency of the process of...

Homework Statement Let \{ B(t) \}_{t \geq 0} be a standard Brownian motion and U \sim U[0,1] and {Y(t)}_t\geq0 be defined by Y(t) = B(t) + I_{t=U}. Verify that Y(t) is a Gaussian process and state its mean and covariance functions. Is Y(t) a standard Brownian motion?Homework Equations The...

Homework Statement http://img291.imageshack.us/img291/4844/14820448wb9.png The Attempt at a Solution First of all I'm trying to find the expected time of a cycle. In a cycle two things can happen: 1) the car lives long enough to reach A with probability 1-F(A) 2) the car fails to...

maximum work during reversible process? I have seen maximum work is achievable when the process is carried out reversibly. Is it correct? For example, if you look at the following problems, 1) Ten litres of an ideal gas at a pressure of 10 atm expands isothermally against a constant...

Hello, I need help with my fourth-year design project. The part that I need particular help with is how to design an evaporator and how to size the fan that will create the forced convection over the fins. What are the main things to consider in terms of design steps? What are some good...

Homework Statement A sample of 1.00 mol of an ideal gas at 300 K and 101325 Pa is expanded adiabatically in two ways: a) reversibly to .5 atm and b) against a constant external pressure of .5 atm. Determine the values of q, w, \DeltaU, \DeltaH, \DeltaS, \DeltaSsurr, and \DeltaStot for each...

So, the problem is: A 200-gram sample of dry air is heated isobarically. Its entropy increases by 19.2 J/K and the work done by expansion is 1.61x103 J. Solve for the final temperature of the air. Okay, since p=const => dq=CpdT thus instead of dq=du+dw we can write dq=dq(Cv/Cp)+dw can find...

We may say a process is adiabatic if it occurs fast enough such that no heat is exchanged from the system.But we also say a process is quasi-static when it occurs very slow. Then how can PV^gamma = c hold for a fast occurring adiabatic process because a polytropic process should be...

Hi everyone, I know that integration is the inverse process of differentiation, and that the definite integral is defined as: \int_{a}^{b} f(x) dx = \lim_{n \to \infty} \sum^{n}_{i = 1} f(x_i) \Delta x assuming that the integrand is defined over the interval [a,b]. My question is: Why is...

question regarding stagnation state and process! stagantion state: it is reference state defined as the thermodynamic state which would exist if the fluid were brought to zero velocity and zero potential. this is the definition from the textbook fundamentals of gas dynamics b Zucker R.D...

Of course Gonzales says he knew nothing! It was only an aide of his who cherry-picked pro-Bush Republicans: http://www.iht.com/articles/2008/07/29/america/29justice.php

I am having a devil of a time trying to successfully perform an iterative process for a particle’s energy in a finite well. The equation describing the energy for a finite well is transcendental thus requiring a graphical or numerical solution. Although, the graphical solution is straight...

What is the process through which photons are absorbed/emitted from an atom? Also... One of the threads i visited first was this: https://www.physicsforums.com/showthread.php?t=76246" Post number 11, the one by Zoobyshoe explaining what Claude meant by the rope analogy using a billiard...

For an ideal gas PV=nRT where n is the number of moles show that the heat transferred can be written as: dQ = \frac{C_V}{nR}VdP + \frac{C_P}{nR}PdV Really not sure where to start with this... I have used dQ = dU + PdV But it hasn't really lead anywhere.

Doing a Cascade Control lab and I'm stuck on a question. Its asking me how to implement critically damped into a control system. I can't find it any where in my books or the net. thanks.

Feynman refers to "renormalization" as a dippy process on p.128 of his book "QED - The Strange Theory of Light and Matter". His words are: "The shell game that we play to find n and j is technically called renormalization. But no matter how clever the word, it is what I would call a dippy...

Hello Lords of Physics, sorry for pestering you guys again but these days a question about irreversibility is pestering me , my question is Why we say that irreversibility in process is due to finite tempreture difference ? so if there is finite temp diff. why process is not reversible...

What is the physical process common to both the emissions of atomic x rays and nuclear gamma rays? is it photoelectric.. or the inverse.

[SOLVED] Isobaric process Hi, need some help with this. I got to moles of an ideal gas that are heated at constant pressure from T=27 C to T=107C. How do I calculate the work done by the gas? I know that for a isobaric process the work is given by W = p(V2-V1) Thanks

I was reviewing some notes on the Carnot cycle and noticed that to compute the work done along an isotherm you take the integral of PdV from the initial to final volume. What value do you use for P since P is not held constant on an isothermal curve? Why is P treated as a constant?

Hi all. We are to compare the effect of a shock wave, that is the irreversibilities associated. We have comptued that the upstream and downstream velocities of a shock wave are 1029 m/s and 266.8 m/s respectively. The upstream pressure and temperature is 105kPa and 290K. What question...

Homework Statement A sample of an ideal gas goes through the process shown below. From A to B, the process is adiabatic; from B to C, it is isobaric with 98 kJ of energy entering the system by heat. From C to D, the process is isothermal; from D to A, it is isobaric with 158 kJ of energy...

Hello to all, I want to analyze and make model of the water mixing process as shown in file in attacment. Basically, there are two input variables: input hot water flow and cold water flow. There is constant flow FL3. I need to write equation that describe how level and tank's temperature is...

Homework Statement Cars pass a certain street location according to a Poisson process with rate lambda. A woman who wants to cross the street at that location wait until she can see that no cars will come by in the next T time units. Find the probability that her waiting time is T...

Homework Statement I was wondering if there was anybody in here with an understanding of the photosynthesis process? If so, would you be willing to read my description of it and ensure that all information is valid and accurate. Thanks

work done in an reversible process is easy to find we have the function of P internal bt when it comes to irreversible process then how do we find work done by the gas or on it and if ur answer is (sry i am new to forum i don't know how to use the features) [ integration p external dv] then...

Hai all my friend I have task from my school about Process of Clouds, Rain, and Struktur of Atmosphere when rain fall. i don't have more knowledge about it so please help me Thanks

Homework Statement One mole of helium is enclosed in a cylinder with a movable piston. By placing the cylinder in contact with various reservoirs and also insulating it at proper times, the helium performs a cycle. Compute the internal energy change, heat transferred, and work perfomed for...

Hi! I was just wondering if in a reversible isothermal process, there is a change in internal energy. I know that for the isothermal forward process the temperature is constant so internal energy is constant? What really stumps me is the word reversible.