Cycle Definition and 617 Threads

Fermilab has been hit by the every-17-years plagues of periodical cicadas. Two days ago, the noise was deafening. Yesterday it was quieter. Today you need to struggle to hear one or two. Dead ones litter the ground. Why do they die at the same time? Emergence took 4 or 5 days. I would expect...

Hello. Physics friends. I am Fisher. I am a process engineer in shipbuilding field. Now I am in a project to design ORC system for ship's WHRS. Let's make a lot of talk together. Thanks.

I will apply for a Ph.D. in Astronomy in the fall of 2023. I want to have a realistic evaluation of my profile to see if I am over-ambitious or not. I think I am out of reach for the "big four" universities. I will donate money to two of them only and will be targeting other top schools...

First i looked at the case of ## \epsilon = 0## and came to the conclusion, that this oscillator has a circular limit cycle in a phase space trajectory, when plotted with the axes x and ##\dot{x}##. I have found that ##x_0^p (t) = a_1 \cos(t)## which implies that all other Fourier- coefficients...

I truly am not sure. I assume it is that because everything has inertia, an a tendency to remain in a constant state of motion, when the clothes are quickly spun around they cannot remain in a constant state of motion (of either rest or constant velocity), but the water is "pushed"/spun out of...

I only know T3 = 4•T1 I was able to calculate the T2 = Tb = T4 I built four equations: T2 = p2V1 / nR T4 = p1V2 / nR p1/T1 = p2/T2 V1/T2 = V2/4T1 I put them together and got T2 = 2T1 I can't figure out the temperatures of A and C. I tend to think Ta could equal Tc (then I would be able to...

New Class of Bimodal NTP/NEP with a Wave Rotor Topping Cycle Enabling Fast Transit to Mars https://www.nasa.gov/directorates/spacetech/niac/2023/New_Class_of_Bimodal/ Ryan Gosse, University of Florida, Gainesville, FL...

Concerning cosmological structures (like galaxies, clusters of galaxies, gas bodies, superclusters...etc) if the elements that make them are close enough they will be attracted towards each other by gravity. Contrarily, if they are sufficiently far apart they will get further away following the...

I am aware that it is claimed that ruminant farming and animal agriculture more generally are significant contributors to anthropogenic emissions. Here in Australia, for example, about 80% of emissions from the ag sector are from methane and nitrous oxide. Various groups propose finding ways to...

6.0 rev - 1 s 1 rev - 1/6 5.0 rev - (1/6) x 5 = (5/6) s = 0.833 s I do not know how to calculate the angular acceleration

During a thermodynamic cycle, an ideal thermal machine absorbs heat Q2 > 0 from a hot source and uses it to perform Work W > 0, giving a cold source a heat Q1 < 0 with an efficiency of 20% . How much is the work done as a function of Q1 ?I have 2 question regarding this problem: 1) Why is Q1 the...

Notable improvement on the Oto cycle engine, invented by Taurozzi in the early 1970s.

(a) We first find that: ##T_A=\frac{P_A V_A}{nR}=\frac{1\cdot 10^5 \cdot 4}{40\cdot 8.314}K\approx 1202.7904 K##, ##\frac{T_B}{T_A}=\frac{\frac{P_B V_B}{nR}}{\frac{P_A V_A}{nR}}=\frac{P_B V_B}{P_A V_A}=\frac{P_A \frac{V_A}{2}}{P_A V_A}=\frac{1}{2}##, ##\frac{T_C}{T_B}=\frac{P_C...

A while back a was messing around in the shop, and ended up making this water pump that uses only heat to pump. The two check valves are the only moving parts. Here is a drawing of what it looks like inside. Here is another drawing of what I believe it is doing in its cycle. The system...

Is this the right path in solving this problem? Am i finding the correct enthalpies? I am also having difficulty understanding so what I've understood is that in a rankine cycle P2=P3 but here P2 is given and P3 has a given variable which is T=25 C too so should I neglect P2=P3? Heres my...

In this cycle/ schematics I'm a bit confused what are the high turbine stage low turbine stage. Does high turbine occur in state 2? and low on state 345? I am still having difficulties in determining what state is the high turbine or low turbine stage occur please enlighten me I'm just new...

Summary:: regenerative rankine cycle Im a bit troubled by my home activity recently and maybe i could use some help this is the problem : In a steam power plant operating on regenerative Rankine cycle with one contact feedwater heater, steam enters the turbine at 8.0 MPa, 350 C and condensed...

A class project requires us to model the Otto cycle using ideal gas properties. We are not given the value for qin (specific heat in) and are told to make an intelligent approximation. My approach to this has been to find the calorific value of petrol, multiplying this by the density of petrol...

Since this is a cycle, there should leave the system unchanged, hence Q+W = 0. I wrote evaluated the heat and work done on/by the system at each cycle as shown in my work. The first question ask is work done at the fourth stage. Since this a cycle and again the system she remain unchanged...

Hi all, I'm doing some research on vapour absorption cycle machines, mainly water ammonia refrigerators. I've got a few questions. 1. What is the role of the water absorber? ie why do we need the water? 2. In the absorber we have a water ammonia solution. Is the ammonia a gas in the solution...

This is pretty interesting. It sounds like GE and the Air Force have been able to make some good improvements recently...

I think I calculated part a correctly by extracting the cp (specific heat) of water from the table which is 4.188 Then calculated Q_dot by simply using the equation Q=m*c*deltaT=10.47kW But I am stuck at part b, I know that the heat extracted from the water is the same as Q_L (rate of heat...

Hello, just wanted to ask regarding the otto cycle; if we were to find the entropy at the phase of isentropic compression and I was already able to derive the temperature 1 and 2 and the pressures at 1 and 2 and I also have the compression ratio of 10. How do I derive the entropy (s1 and s2)...

Hello all, The merits of the full-flow cycle are without question and have been fielded with Starship tests to the point of my complete buy-in into Raptor's capability as a launch engine. Elon Musk loosely discusses further refinement of their vacuum-optimized engine that they have created...

I have an air condition that is 9.000 BTU and it states at the external unit that its Power is 1.2KW. However because I know that an air condition has inductive loads (motors) its power factor is not 1 so I am not sure 1.2KW is the real power consumed. I am thinking to calculate the power...

Basically this would be a closed loop geothermal system for electrical power generation. The system would consist of 2 Horizontal Wells connected creating a U-shaped closed loop cycle using thermosiphon effect, with constant recirculation. It's not really a conventional geothermal power...

Hello All Numbers vary, but the consensus is that an average person can cycle much further in a given time than they can walk or run. The world record for running is about 300km in 24 hours, whereas the cycling record is about 900km. A more typical comparison might be that a fit athlete could...

Greetings! I'm a recent ME grad and I'm trying to design a refrigeration system for the first time. I understand most of the theory and calculations (I guess not, cause I wouldn't be here otherwise), but I'm having difficulty applying it to the real world. Homework problems in college often...

AIUI, the early universe, after the Great Recombination, was a fairly, but not absolute, isotropic cloud of mostly H, with some He. Eventually regions of the cloud coalesced into stars, and if the mass was big enough, the temperature & pressure in the star core was sufficient enough for H in...

The v(t) = 120##\sqrt(2)\sin(2\pi 60t)##. Let the resistance of the heater be "R", then the rated power = 1500W. The rated power is the average power 1500 = ##\frac{120^2 *5 * 60} {12*60 * R} ## ->eq1 R = 4 Ohm. a. Instantaneous power is ##P = \frac{v^2} R ## -> eq2 ##P =...

So far I have come to the understanding that a nanosecond is one billionth of a second or 10-9 seconds. So I found this formula to calculate the clock cycle in nanoseconds, for a CPU running at 2.5 GHz. 10^-9 x 2.5 x 10^9 = 2.5 nanoseconds Am I missing any important steps with my calculation...

In AB, dU=0 (Isothermal) Hence dQ=dW W1= RT ln(2V/V) = RT ln(2) = 800R*ln(2) Q1=W1 = 800R*ln(2) Q2= Cp(300-800)=-500Cp = -500*2.5R Q3 = Cv(800-300) = 500Cv = 500*1.5R So Q= 800R*ln(2) -500*2.5R + 500*1.5R = 800R*ln(2) -500R Hence net heat absorbed is 800R*ln(2) -500R But. Suppose I find...

What kind of service life can I expect from small hobby servomotors? Can I exceed current rating for increased power? How will that affect duty cycle? Thanks so much in advance Joe

Consider a reversible ideal gas cycle consisting of: 1. An isochoric heat addition, 2. An isothermal expansion to the initial pressure, and 3. An isobaric compression to the initial volume. What, if any, is the difference in net work done by the gas in the cycle if the isochoric heat addition...

Can efficiency be larger than 100%? I have double checked the values of enthalpy of point 1,2,3 from R-22 tables. And I obtained enthalpy of point 4 from the work done given. Thank you.

The Allam-Fedvedt cycle is a method to burn natural gas without releasing Carbon to the atmosphere. www.netpower.com claims they have a 50 Mw commercial grade power plant using this innovation and I hope that is the case. Netpower states they are building a 300 Mw plant. This NEEDS TO BE...

Hi, This is not a homework problem, I am trying to analyze how various parameters affect a boost converter operating in DCM most of the time. The input and output voltage is fixed so I will eventually like to sweep parameters for D, L, T, Vi, and R. R is less important though. Here I am using...

1-->2 (adiabatic) $$P_1V_1^γ=P_2V_2^γ$$ $$P_2=18,4.10^5Pa$$ $$T_1V_1^{1-\gamma}=T_2V_2^{1-\gamma}$$ $$T_2=429,32K$$ 2-->3 (isochoric) $$\frac{P_2}{T_2}=\frac{P_3}{T_3}$$ $$\frac{18,4.10^5}{429,32}=\frac{P_3}{T_3}$$ 3--> 4 (adiabatic) $$P_3V_3^{\gamma}=P_4V_4^{\gamma}$$...

The brightness of an LED is a result of the current passing through it. The current is a function of the voltage across the LED. The duty cycle represents the percentage of the time period that the signal is in the ON state ( which means that the voltage is at max value as compared to 0 V for...

So we know that every reversible engine working between the same temperatures will have the same efficiency(the same as Carnot engine). So let's consider for example reversible Otto cycle. So as you can see on the picture it is operating between ##T_1## and ##T_3##, so I was thinking that it...

Is there a mathematical explanation for why the work done in the condenser (in process 2 to 3) is zero? I am aware that ammonia does not expand or compress in the condenser, only changes phase, but without knowing that the process takes place in a condenser and only considering the graph...

Do all stars in their life cycle (t) emit energy (E) that follow a bell shape curve? If yes, is the curve symmetrical always? How is this related to nuclear and thermal time scale?

I would like details on CNO Cycle Carbon Fusion about the exact energy release of an entire cycle through the reaction and other details you would think would be important about the CNO cycle.

A Rankine Cycle heat engine uses ammonia as a working fluid, turbine entry temperature is 25 Bar at 60 degrees Celsius. The turbine outlet pressure is 4 Bar, the question is: what is the outlet temperature? and if the output power is 6 Gigawatt (6x10^9 watt) what would the mass flow rate of the...

Hey! :o We have the following permutations in $\text{Sym}(14)$ : - $\pi_1=(1 \ 2\ 4 \ 9)\circ(1 \ 3)\circ (6 \ 8\ 12)$ - $\pi_2=(2 \ 4\ 5 \ 8\ 7)\circ (1 \ 12 \ 6)\circ \ (13 \ 14)$ - $\pi_3=(1 \ 4 \ 5\ 8 \ 11)\circ (2 \ 4\ 6 \ 5 \ 1)$ 1. Determine the cycle decomposition of $\pi_1...

Hi, I was just wondering about the efficiency of a cycle that is not Carnot cycle. In that case one should use \eta = 1-\left|\frac{Q_{\rm out}}{Q_{\rm in}}\right|, where Q_{\rm in} and Q_{\rm out} are the amounts of heat absorbed and released during the cycle. For instance, I guess that in...

m=Q/c(79*ln80)

I'm taking an online course that covers the Rankine power cycle, that, unfortunately, isn't mentioned in any of my textbooks. Do you guys have a textbook that covers this cycle? Thanks

Hi, I see that a newspaper is making a claim that Zharkova identified a 2000-year cycle causing some significant variations in Sun-Earth distance with a cycle of 2000 years, seemingly because of the perturbations caused by Jupiter making the Sun orbiting a barycentre slightly eccentric. This...

An ideal diatomic gas undergoes an elliptic cyclic process characterized by the following points in a ##PV## diagram: $$(3/2P_1, V1)$$ $$(2P_1, (V1+V2)/2)$$ $$(3/2P_1, V2)$$ $$(P_1, (V1+V2)/2)$$This system is used as a heat engine (converting the added heat into mechanical work). Evaluate the...