Process Definition and 1000 Threads

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

Hello PF. I need some serious advice as to how i can survive until i transfer to a 4 year university. I am an 18 yr old HS senior. Contemplating on dropping out. I have 27 HS credits out of the 21 needed; I also have 36 credits at Community college w/ 4.0gpa. I received a two week notice from...

Hello again, I have a little dilemma that I have spent a lot of time thinking about, and I was hoping someone here could help me out, it would be very kind of you to do so. During the last UCAS application process I got accepted to an undergrad programme in Physics at Heriot-Watt...

Helium gas initially at 2 bar, 200K undergoes a polytropic process, with n=k, to a final pressure of 14 bar. Determine the work and heat transfer for the process, each in kJ per kg of helium. Assume ideal gas behavior. Ok so I have the following: P1=200kPa T1=200K R_He=2.0769kJ/kg*K...

I'm studying the Poisson Process (rate R) and I'm hung up on the issue of dependence. This seems like and easy question but I have no background in probability whatsoever. By definition, the number of events in disjunction time intervals are independent. Okay. Fine. But say we have an...

In the Leaching process of Aluminium, alumina present in bauxite dissolves forming a soluble sodium aluminate. The impurites are filtered off. The filtrate is diluted and a little freshly precipitated aluminium hydroxide is added which causes the precipitaion of aluminium hydroxide. How does...

Right now I am applying to approximately 20 PhD programs while having to work a full time job and I think I am going to die. I constantly find myself having to spend hours and hours on websites digging through schools' websites to find information that is buried on how to apply, deadlines, etc...

Homework Statement Two moles of helium at 27 deg Celsius occupies 20 liters. The gas is expanded first at constant pressure until the volume has doubled, and then adiabatically until the temperature returns to its initial value Treat helium as an ideal monatomic gas and assume that both...

Homework Statement Suppose that one mole of an ideal gas expands in a quasi-static adiabatic process from P1 = 1 Pa and V1 = 1m3 to V2 = 8m3. What is the change in the pressure and the entropy of the gas? Homework Equations PV\gamma=constant The Attempt at a Solution I can't come...

Hello Why ds=0 only in a steady rev. process? Can't it be zore for a rev. and not steady process? And if the process isn't rev. but still circular. since the entropy is still a state function it should still be zero if we come back to the starting point ,right? if it isn't true then dU...

Does there exist a known process to devulcanize rubber (i.e., getting out all the sulfur crosslinks from the polymer chains) and get out of the process rubber that can be revulcanized? Or does one big slash on a tire mean that 20-30 pounds of rubber can never be used for making tires again?

i have problem to understand the concept of process control system... anyone can help me to find source or link that related?

I hope someone in here can help me out of this problem. I know that for calculating the change in entropy of a system (\Delta S) we can use this formula : \Delta S=\intδq/T Well the problem is here, when we calculating ΔS for an adiabatic process we know Q= 0 so ΔS=0 in this process, but...

Homework Statement In a quasistaic adiabatic process in a monatomic ideal gas PV^5/3 = constant [DO NOT PROVE]. A monatomic ideal gas initially has a pressure of P0 and a volume of V0. It undergoes a quasistatic adiabatic compression to half its initial volume. Show that the work done on...

^^^ Any way to get to it by using size / weight / etc.?

Homework Statement I am in a hurry with the following problem: We have a source that produces binary symbols, 0 and 1. 0 follows a 0 at probability 7/8 1 follows a 1 at probability 1/2 A) Calculate probability of the symbols 0 and 1 to appear. B) Calculate entropy of source. The...

Homework Statement A pistol-cylinder device contains 0.8kg of nitrogen initially at 100kPa and 27 degrees C. The nitrogen is compressed in a polytropic process during which PV^1.3 = constant until the volume is reduced by one half. Determine the work done and the heat transfer for this...

Homework Statement An Ideal Gas at 300K has a volume of 15L and a pressure of 15 atm. Calculate the change when the system goes under a reversible adiabatic expansion to a pressure of 10 atm. Gamma = 5/3. Cv = 1.5R. q = 0(definition of adiabatic processes).Homework Equations dw = P DV...

Homework Statement An ideal gas is taken from an initial temperature Ti to a higher final temperature Tf along two different reversible paths: Path A is at constant pressure; Path B is at constant volume. The relation between the entropy changes of the gas for these paths is a) delta S(A) >...

Homework Statement A crude oil preheater furnace has a simplified mathematical model for the process obtained by applying a steady-state energy balance that requires that: Heat input through fuel = heat required to heat feed from T(i) to T, ie: \lambdaf.Qf = F.Cp.(T-Ti) Here, Cp is the...

Could somebody explain in detail, how intercalation process works? For exampe, when Li ion intercalates in graphite where goes external (valent) electron of Li atom? Does it become common with graphite atoms? Is this true that smaller ions easier intercalate into substrate? What`s about...

Our laws that describe entropy to be irreversible using our macroscopic experiments in which they always come out with a certain outcome. However, I think there is no such thing as an irreversible process on a quantum level and the quantum level is the stronghold of everything. Everything is...

Hi all. I have been thinking about this problem for quite a while now. Still kinda clueless. We know that when we apply electromagnetic radiation on an atom/molecule, then depending on the frequency of the radiation the atom/molecule makes electronic transition. We know how to get the average...

If you have a 32 bit processor, does that mean it is useless to have more than 4 GB of RAM, since you wouldn't be able to address those additional locations? So with a 64 bit processor, technically you could buy as much RAM that fills 4 EB (exabytes)? Why does it jump from 32 bits to 64...

I understand that an isothermal process occurs at constant Temperature. And for an ideal gas, the the internal energy is a function of temperature only. Therefore, when Temp = 0, then U = 0 also, meaning the internal energy of the gas doesn't change... and we have q = - w or basically q = PΔV...

we know that particles produced in radioactive decay process, such as alpha and belta particles, can produce "ion pairs" along their paths. Does the "ion pairs" means "positive ion and election pairs" or "positive ion and negative ion pairs" ? I am not sure whether negative ions can be produced...

Hi, I am posting a new question regarding a quasistatic process. My lecturer writes in his lecture notes the following: (Imagine a gas in a cylinder being compressed by a piston. Then,) "Quasistatic compression: F = (P + deltaP)A, where deltaP is average pressure change as piston moves an...

Wikipedia defines a quasistatic process as "a thermodynamic process that happens infinitely slowly. However, it is very important of note that no real process is quasistatic. Therefore in practice, such processes can only be approximated by performing them infinitesimally slowly." I do...

Can you help me with this problem? An ideal gas is compressed adiabatically. The work done over it is 200 J. How much will the internal energy change? A) 200 J B) 100 J C) -200 J D) 0 J Which formula do you use to solve it? Thanks in advance!

Homework Statement Three moles of an ideal gas are taken around the cycle abc. For this gas, Cp= 29.1 J/mol K. Process ac is at constant pressure, process ba is at constant volume, and process cb is adiabatic. The temperatures of the gas in states a, c, and b are Ta= 300K, Tb= 490K, Tc=...

Here we go again! :smile: I am taking a graduate thermodynamics course and I feel like I am in physics 1 all over again. The definitions that I took for granted early on in my education I am really wanting to make sure that I have a firm understanding of before I progress. I am reading from...

More and more I'm thinking that I'd like to do high energy physics in grad school. But at the same time I recognize that I'm not a genius and the competition is very stiff in high energy physics. So I'm wondering if applying to a particular school for their high energy program would make it...

Hi: I want to know the quadratic covariation of Brownian motion B(t) and poisson process N(t).Is it B(t)? Thanks !

Homework Statement Is this impossible: (yes or no) During an adiabatic process, 37 J of work was done on the system. Homework Equations Delta U=-W The Attempt at a Solution I think it is impossible because it says work is negative. I am not sure though.

Homework Statement What are the definitions and functions of drawing, trimming, and beading processes in metalworks such as in manufacturing process?

Homework Statement The Attempt at a Solution Part (a) is no problem, it is simply P(X>10) = 1 - P(X<=10) which requires the use of tabulated cumulative poisson values. Part (b) is throwing for a loop. I know that I need to invoke the Gamma distribution since that is what the...

Homework Statement Pf 429 Q -754 ΔU 819 The table above shows the measurements taken while an ideal gas underwent an ISOBARIC process. Fill in the appropriate values for the table below. ΔP=? Homework Equations Q= ΔU+W=ΔU=PΔV The Attempt at a Solution I don't know how to go...

Homework Statement A monatomic gas has V1 P1 and T1 (volume pressure and temp) at state 1 The gas then goes through the following process adiabatic expansion to stage 2 (exapands to twice its volume) isovolumetric heating so it gets back to T1; stage 3 isothermal compression back to...

Homework Statement Let A and B be subsets of R (real numbers). The vector sum of two sets A and B is written as A+B and is defined to be: A+B = {a+b : a in A, b in B} Prove that for all bounded nonempty sets A and B, sup (A+B) = sup A + sup BThe Attempt at a Solution let A* = sup A, B*=sup B...

Homework Statement The fireball of a uranium fission bomb consists of a sphere of radius = 15m and temperature 300,000K shortly after detonation. Assuming that the expansion is adiabatic and that the fireball remains spherical, estimate the radius of the ball when the temperature is 3000K...

Homework Statement a) Calculate the entropy change when Argon, at 25oC and 0.101 MPa pressure, in a container of volume 0.5 litre is allowed to expand to 1.0 litre and is simultaneously heated to 100oC. b) Calculate the entropy change when the same initial sample is compressed to 0.05 litre and...

Not sure if it belongs here, if not then please move it. So basically an indian engineer is nominated for a nobel prize, and doesn't get it. He http://news.indiainfo.com/2003/07/07/07nri.html claiming the process is flawed. Any merit to this, or is he just being a sore loser? Thoughts?

Hello physics forum, can someone please explain to me the thought process that one uses to solve a question like this? A leak has been discovered in a water supply pipe that will take several days to repair. Suppose that it is leaking at a rate given by the function 4 + 0.2t, that is...

Homework Statement Find the area bounded by y=1-x^2 and y=x-1 . Homework Equations The Attempt at a Solution i know it can be done like this \int^1_{-2} [(1-x^2)-(x-1)]dx we sort of shift the x-axis below . From what i understand , integration is a process of finding the...

Hey I'm really struggling with this: What is the expected value of a poisson process (rate λ, time t) given that at least one even has occured? I was told the best way was to find the conditional distribution first. So this is: P(Xt=z | Xt≥1) = P(Xt=z, Xt≥1) / (PXt≥1) = P(Xt=z) /...

Hi, I was wondering what is the process of getting published. If I've been doing labwork for two years and my teacher said she'll be able to write up on this research soon. What happens after she finishes writing the paper? Where does it send to and who decides to get it "published" and...

Homework Statement There is a temperature-Entropy graph (T-S) (attachment),which illustrates a hypothetical cyclic process. a) Calculate the heat input or output along each of the paths. b) Find an expression for the efficiency η of the complete cycle in terms of T1 and T2 only...

Homework Statement I cannot figure out this example: suppose that initially individuals enter a room from one door according to a Poisson process with arrival rate lambda1. Suppose that as soon as one inidividual enters, this door is shut down and a second door is open. The numer of...