Channel Definition and 186 Threads

hi, for studying one decay channel of particle - and measuring its decay width or life time - after this how do we proceed to find the branching ratio - do we need to find the decay width of all possible channel - because its possible even by experiment we are missing some possible decay...

I’ve read that the Ca2+ channels in neurons can be manipulated through the use of certain radio wave frequencies. And the resulting internal/external charge differential will cause the neurons to fire. Does anyone have any more insight into that?

Quite rare to get one on film so worthy of a thread on its own,"It is just the seventh time an asteroid impact has been predicted in advance. The European Space Agency tweeted that it was "a sign of the rapid advancements in global asteroid detection...

https://www.cnn.com/2022/11/10/world/shuttle-challenger-nasa-discovered-documentary-crew-scn

I want to determine the normal flow depth in a perfectly horizontal circular conduit. The system characteristics are known (Internal pipe diameter, Mannings roughness, Discharge). However, I am not sure how to calculate the normal flow depth. When using Manning's equation one can find the normal...

Hi! I'm playing around with a type of electron (and by electron/molecule interactions: ion) source that was briefly touched upon in the 1960's. The basic idea is to use a channel electron multiplier "channeltron" with the anode removed; similar to a single MCP channel. The burst of electrons...

In general, if R is the recovery channel of an error channel ε, with state ρ, then and according to these lecture slides, we get the final result highlighted in red for a bit flip error channel. I am simply asking how one reaches this final result. Thank you (a full-ish derivation can be found...

Hallo. Since I'm new in this field, I hope someone can help me. I have a laminar, steady state, incompressible flow in a channel (a fully developed). Geometry of the channel is on the photo. How should I calculate the drop of static pressure across the channel? Since I have Re, I did calculate...

Hi what dynamics are moving liquid in open channel flow without slope (irrigation channels)? Are they mostly hydrostatic forces? imagine 2 scenarios 1. Channels are empty and are being filled for the first time. What forces drive the liquid until it becomes big static lake? 2. Channels are...

So I am a bit uncertain what approach is best for solving this problem and how exactly I should approach it, but my strategy right now is: 1. Solve the time-independent Schrödinger Equation with the given Hamiltonian and find energy eigenvalues of system: -Here I struggle a bit with actually...

I was reading that the mysterious reason why this channel was removed from public use is because it interfered with radio astronomy (the Wikipedia article didn't mention the reason). So what is going on at this frequency?

I found, what appears to be, a good channel on General Relativity and other science topics. I'm dubious because... the internet. I'd love a second opinion on whether this channels first few videos on The Maths of General Relativity are doing it justice. I'm a dad with a day job and I can't...

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Hi guys, I am confused about the heat transfer mode of between two contacting material, especially in a channel flow. Obviously, conduction or convection dominate the heat transfer process in the process with low object temperature . But I am not sure if I have a fluid of 500 Kelvin, flowing...

Hi All, I need some help to figure out how to best go about setting-up and analyzing a micro-fluidics design problem I ran across in my research. It's not the typical single-surface contact angle adhesion kind of analysis. Basically, I have a wide micro-fluidic channel that's formed by a...

Regarding human vision and the retina: Where are these channels produced? To put it simply, is it produced in the eye or in the brain. For example; does light enter the eye, hits the retina and it applies a series of filters to produce these 2 different channels (the parvo and magno) and it...

Hi PF! I'm simulating two fluids, air (blue) and water (red), in a 2D rectangular channel. See picture below: I've turned gravity and viscosity off, and have ##\rho_w=1000## kg/m^3 and ##\rho_a = 0.01## since it cannot be zero. I've also enforced a static contact angle of ##\theta = 71^\circ##...

My problem: In the solution,our teacher found, that the wet section is minimal if y=L/2 So Am: = L^2 /2; Pm: = 2L; So despite that I try with any value, I can not find a more minimal section, and that's not the case because if I try with y = L / 3 I find Am: L^2/3; Pm: (5/3)*L ; and these...

Hi All, I'm looking for an analytical solution to the open channel rectangular fluid flow profile. The flow is bounded by three walls but the top is open to atmosphere. Assume steady state flow that is parallel and incompressible.I've already found information involving a rectangular flow...

Hi, I'm struggling to understand how channel length modulation takes place in mosfet. The books n internet said that as drain side is positive, there is less potential difference between positive gate and positive drain, while there is more potential difference between positive gate and zero...

Hi everyone, I would like to know the formula for calculation of velocity and shear rate in my rectangular fluid channel. Here are the important values regarding my rectangular channel. W= 2.5 mm, H=3 mm, L=35 mm. Fluid: Diluted Bacterial suspension derived from wastewater. Flow rate: 0.125...

Hi, I'm studying MOSFET in detail and I'm struggling to understand how the channel is formed in case of SOI Mosfet. For normal mosfet A positive Gate to source voltage attracts electrons from P substrate towards Gate and thus a channel is formed. But in case of SOI There is a buried Oxide...

Can anyone take a look at the following video, and then look at the attached drawing, and tell me: Why shouldn't the design described in the drawing, improve upon the channel wing lifting force? Here is the video: Here is the drawing:

Homework Statement Determine y2 (ft)and v2 (ft/s) using the momentum principle assume widths are the same at 1 and 2 Homework Equations from what i remember in my past fluids class, the momentum equation is: Force = Qvout - Qvin assuming same density and direction However in my lecture the...

Homework Statement [/B] We have water flowing in an open channel. A small tube is placed in the channel, and the water raises to a height "l" above the water surface. The distance from the water surface to point 1/2 (points are at same height) is d. At point 1 the fluid velocity is V1 and at...

Hello, I found a paper on the calculation of probabilities of error. However, I didn't know how to plot the graph using equation 3 and 4. These are the list of equations: And this is the graph: I hope that anyone in this forum may guide me to plot this graph. Thank you.

Hi everyone, Non-physics student here, and slightly in over my head :D I am slightly stumped for ideas regarding the calculation of the shear rate in a rectangular type channel, which I need to effectively simulate a blood flow type condition in a channel that has to be rectangular due to the...

Hi guys The IF section of both monochrome and colour receivers must include rejection filters to suppress adjacent channel interference... Why exactly so, since the work of rf tuner in television receiver is to select a particular channel and as the required channel is selected it then passes...

Do we know roughly what the surface of a protein channel looks like? In most of the diagrams they are depicted as a sort of cylindrical tube with a smooth surface, but I'm curious if there are some more detailed documentations somewhere? For example I know they aren't rigid objects and may be...

Hi, I am looking for the differences between 16-bit, 24-bit and 32-bit colors for a while. I saw that actually 32-bit color is also like 24-bit color but plus 8-bit alpha channel. Since 8-bit information represents 256 possible values for each color channel, what does 8-bit do exactly for alpha...

Hi PF! I'm trying to model a fluid dynamics problem where there is flow in a wedge. Length scale is 160mm and two fluid phase: air sits on top of silicone oil. Boundary conditions can be to specify height conditions, flow rate, et cetera. Very low gravity, so surface tension is very relevant...

a microchannel of length 2L and width h in the thermal cycling region. the temperature profile ...(1) the cyclic temperature profile leads to a time dependent density ...(2) using the mass conservation equation i.e. ...(3) and momentum balance equation i.e. ...(4) we have to find the exact...

Say you have a rectangular channel with a width, w (m), and a height, h (m) and an infinite length. The channel itself is fixed and none of the sides can move with respect to one another. If you know the volume flow rate, V (m3/s) of fluid through the channel, how do you calculate the shear rate...

Good morning and my compliment for their infinite knowledge contained in this forum. I'm struggling to keep being my girlfriend's hero. I have here a nail led 36w UV led lamp that failed last week. Bulbs are tested all ok and connected in two channels each channel in series of 9 LEDs of 2w...

Homework Statement When a part of the channel is constricted , why will the Emin = Eo ? Homework EquationsThe Attempt at a Solution I just have the figure showing in case 1 and case 2, Emin = Eo without any explanation ... Can someone explain about it ? I tried to search many online resource ...

For those of you interested in the racier side of Albert Einstein National Geographic Channel has started a series on it: https://www.theguardian.com/tv-and-radio/2017/apr/24/genius-review-geoffrey-rush-impresses-as-an-unexpectedly-racy-Albert-einstein I've yet to see it but would be...

Similar to the bursting of a dam holding back glacial lake Missula which created a deluge that scoured eastern Washington State and created the Columbia River Gourge, a Glacial lake in the area of the North Sea may have spilled out (twice) over a land bridge connecting England to France and...

Can someone explain this paragraph especially the bold part in simpler language: "If it is not in a major crystal direction or plane ("random direction", Fig. 2), it is much more likely to undergo large-angle scattering and hence its final mean penetration depth is likely to be shorter." full...

Hi, help me out with this one , I have wanted to understand this for a long time, I know different reactors have different approaches to active zone design but here I want to understand how the fuel channel of a RBMK reactor works, I know there are types of reactors like BWR in which I assume...

Hi PF! I was recently looking at two immiscible fluids in a 2-D Poiseuille Flow with two immiscible fluids of different densities. Let the total distance of the channel be ##L+\epsilon L##, where the dividing line between the two flows is ##L##. I was thinking of the possible flow profiles and...

1. Can a fluid which is accelerating down an inclined channel with constant acceleration still satisfy the continuity equation for a constant-density fluid? Since the acceleration will be down the slope, in the streamwise direction, then surely ∇⋅U > 0? 2. Assuming that continuity is satisfied...

Homework Statement I want to generate a Ricean channel using MATLAB Homework Equations Assuming that Ω = -30 dB. The Attempt at a Solution I know how to generate a Rayleigh channel using matlab: H = 1/sqrt(2) * ( randn(N,M) + j*randn(N,M) ) But I really have no idea how to do that for...

If I look at the lower limits on the proton decay lifetime \tau set by, say, Super-Kamiokande, I'll see different lower limits depending on what the proton could decay into, eg. \tau_{min}(p \rightarrow K^{+} \overline{\nu}) < \tau_{min}(p \rightarrow \mu^{+} \pi^{0}) < \tau_{min}(p \rightarrow...

Hi everyone, I'm trying to simulate an OFDM following a few steps, and I'm stuck at the first: The first step: You have a channel with independent zero mean complex Gaussian taps along with exponentially decaying power profile E{|hk|2|}=e-k/3 with k ∈ [0,21] First of all, does this notation...

Sharing this funny video from the ASAPScience channel:

Homework Statement I was told that the flow rate in open system at 2 points in the pipe system are not the same, is it true?? Homework EquationsThe Attempt at a Solution

Dear Fellow Engineers I'm having an issues with my calculations. This case concerns a open channel flow that start off being supercritical on the left and turns into subcritical flow after a hydraulic jump. Given: Volume flow rate Q = 0.16m^3/s Width of the channel b = 1m Resulting...

I have a hard time understanding what a channel that transmits classical information is in the framework of quantum information theory. My textbook says the following: Let P(ylx) be a classical channel defined by a conditional probability distribution. We define the corresponding quantum...

This is not homework. I am doing old exams so i have the full solution but need help understanding it. 1. Homework Statement A WSS random signal {X(t)}t∈R with PSD S_X(ω) is transmitted on a noisy channel where it is disturbed by an additive zero-mean WSS random noise {N(t)}t∈R that is...

Sodium ion flows a through a cylindrical ion channel --> diameter = 0.85 um and is 5 um long. potential difference b/w the ends of the channel is 225 mV drift velocity = 0.015 m/s in a period of 1 ms, a total of 15*10^6 ions exit the channel a. total charge exiting the channel in 1 ms =? b...