Film Definition and 309 Threads

Hi PF! If we have flow around a curved object that is sufficiently thin, I Have seen many texts assume the surface is linear rather than curved. Can someone help me with what "sufficiently thin" is quantitatively and how this allows us to neglect surface curvature? As a simple toy problem...

Hi, in every explanation of thin film interference I came across, little or nothing is said as to why the layer of transparent material creating the effect should be thin. What would go wrong if that is not the case? I'm asking because it seems to me that, in principle, the mathematic...

Hi, I'm trying to understand the derivation to an equation I found in the following paper: http://pubs.acs.org/doi/abs/10.1021/nn203035x I posted almost this exact question on Physics Stack Exchange but got no replies so I decided to try it here instead, I hope that's ok...

I am working on a project to stockpile and freeze photographic film and paper for later use. This is not for academic or commercial purposes, but just for personal use. I've been experimenting and am stumped as t the following: I place a package of film in a ziplock bag in an environment of...

Homework Statement The problem is given. Homework EquationsThe Attempt at a Solution I tried to solve the question as if there is a nanowire between two reservoirs and got an answer. But I don't know what should I do to measure thermal conductivity in a thin film. My formula for k in a...

Homework Statement Monochromatic light, at normal incidence, strikes a thin film in air. If λ denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum? A λ/4 B 3λ/4 C λ D much less than λ E λ/2...

Homework Statement A thin film of oil (n=1.5) is floating on top of water. When looking directly at this film, a large portion appears red (700nm). What is the thickness of the red part of the layer? Homework EquationsThe Attempt at a Solution Since n for oil > n for air, there will be a phase...

Homework Statement I am working on a thin film interference problem where i have to find the phase difference. What is the relationship between external/internal reflection and the thin film interferenceHomework Equations for external: [/B] for internal: The Attempt at a Solution So far i...

Hi every one , I want to find the refractive index of a thin film using it's reflectance and transmittance spectrum is there a way to do that ? thank you for advance

Homework Statement As shown in the figure below, beams of light whose wavelength in air is 600 nm are perpendicularly incident upon two transparent thin films (A and B) in the same phase. The thickness of A and B is l. The refractive indices of A and B are, respectively, nA and nB. The...

Looking for recommendations for two commercially available films and coatings, the best for... #1 - Maximum reflectance, regardless AOI, for short wave sunlight primarily and, secondarily, reflects some or a lot of long wave, and thirdly, also good emissivity for any of the spectrum. Appreciate...

Hey everyone. Just a basic question out of curiosity. How effective are UV films for windows for blocking UV rays? Every window film I see says it blocks 99% of UV rays. I just put them in my house, and honestly, I find it hard to believe that it is blocking 99% of UV rays (that being rays from...

Hello, I'm working on simulation of hydrogenated amorphous and microcristalline silicon solar cells. The software I use is AMPS 1D So, I need (n,k) of hydrogenated amorphous silicon carbide (a-SiC:H) Thank you

1. The problem statement, all variables and given/known da A soap bubble 500 nm thick is illuminated with white light. The index of refraction of this unique soap film is 1.35 for all colors (no dispersion). a) What wavelengths are not reflected? Homework Equations 2nt=mL 2nt=m(L/2) The...

Homework Statement Homework EquationsThe Attempt at a Solution SiO2 as the thin film,when light entry SiO2 and Si then the reflected light has 180 phase change, for dark fringes 2nt=(m+1/2)λ for bright fringes 2nt=mλ for dectect max of bright/dark,-1<=sinx<=1, then no idea to prove father[/B]

here is the problem. i got 0.5 from the fact that thickness = (m)(lambda)/(2nf) other equation for thickness is thickness = (m+1/2)(lambda)/(2nf)

One of his most notable creations was the War Room in Kubrick's Dr. Strangelove. He also did sets for the 1960s James Bond movies. Washington Post Berlin Film Journal

If the equation for phase difference, 2(pi)(path difference/wavelength) gave you a value like 12.25pi would that be the phase difference or would it be .25pi?

Hello, a long-awaited fan film has been released on Friday. I'd say it's pretty good.

Prompt 3. How do you read the final scene of Thelma and Louise? Is it a fitting conclusion to the film? Does it shed new light on meanings of the road? The main topic in the course is road narratives. I need feedback for my essay. It's just a 3 page essay. I need also new ideas to finish my paper.

Homework Statement This is not exactly a homework problem. I am trying to review material so that I can tutor it this semester. In the falling film problem, as described in this link: http://www.syvum.com/cgi/online/serve.cgi/eng/fluid/fluid204.html, I am confused why the velocity profile does...

Hi All, I'm searching for the possible method to determine organic coating thickness cover on steel tole was plated by thin zinc layer. Additionally, I also want to measure thickness zinc plating layer in between these layers (coating on top & steel on bottom) without destructing them. Please...

I was born and raised in Czechoslovakia (currently the Czech Republic) where I completed my Masters degree in Physics and Philosophy. I recently completed my PhD in science education and I am looking for "my place" in academia. In my dissertation I focused on a problem of students' understanding...

An unfortunate incident happened at our triple effect caustic evaporator (32w.t% to 51w.t%). The third effect (highlighted red) where major steam (~12-13bar depending on flowrate) assisted evaporation take place, here for some reason Ni tubes get severely collapsed, while the plant was offline...

Homework Statement You are designing a thin transparent reflective coating for the front surface of a sheet of glass. The index of refraction of the glass is 1.52 and when it is in use, the coated glass has air on both sides. Because the coating is expensive, you want to use a layer that has...

Hi PhysicsForums, Here's a thin film interference question I'm having problems with. An oil film (n=1.50) floats on a water body (n=1.33) in an air environment. Normal incident white light is reflected by the oil film. But in the spectrum of reflected light, 500nm and 700nm light are missing...

Homework Statement The height of motion picture film's frame is 35 cm.If 24 frame go by 1 sec calculate the total number of frames required to show ia 2h long motion picture. Homework Equations simple Equation which I don't need to write here I guess The Attempt at a Solution The Height of...

Who is excited for this film? I love survival films and his one is hot on my radar! http://www.imdb.com/title/tt3659388/

I for one really enjoyed the first Prometheus. Yes there were some plot holes, but it was spooky and haunting. Plus the Alien universe is so cool! Anyway, here is a new Interview on Ridley Scott about the title and movie etc. http://www.heyuguys.com/prometheus-2-title-ridley-scott-interview/

Not really physics, but I thought this forum would be most interested in this. http://gizmodo.com/charges-dropped-against-temple-university-physicist-acc-1730326640 http://www.nytimes.com/2015/09/12/us/politics/us-drops-charges-that-professor-shared-technology-with-china.html

In Understanding Quantum Mechanics, Ch.1, Sec. 5 Roland Omnes says: ".. hard x-rays can leave straight-line tracks in photographic emulsion and this is strongly reminiscent of a particle trajectory." How can we describe this in terms of the wavefunction / interaction / measurement paradigm? Is...

The efficiency of a scientific camera like http://www.princetoninstruments.com/products/imcam/proem/ is specified by the quantum efficiency vs wavelength. The meaning is simple enough. Assuming a fill factor of 1, it's the fraction of incident photons that generate a charge. But photographer...

A wavelength of incident light on a thin film is given, and also is known how much the rays coming out from the top surfaces are out of phase. How can be the thickness of the film calculate?

I know if takes some liberties (most glaringly the relative time dilation on Miler's planet), but it provides some wonderful scenes. The Launch The Wormhole The Black Hole itself Incredible. I bet it sparks an interest in astronomy and physics for a younger generation

When photons reflect from a mirror coated with, say, an aluminium film... the reflection is presumably down to their interactions with free electrons in the metal (and each electron is in an unknown state before and after). Yet the interference does not go away if a mirror is inserted in one...

Hello Forumers and Physics-addicted Fellows! I'm an applied nuclear engineering scientist by profession and thermal physicist by education. well nowadays I'm really involved into the describing the processes in Light Water Reactor core during Emergency Core Cooling System in action. In details...

Homework Statement http://lon-capa.bd.psu.edu/res/psuerie/gwb6/physics/optics/e1p4.png A thin 200nm film of oil (n = 2.0) floats on water (n = 1.33). To a normal human, what wavelength will the film appear when viewed from above (nearly perpendicular to the film)? Homework Equations for...

Homework Statement A thin film of oil (n = 1.50) is spread over a puddle of water (n = 1.33). In a region where the film looks red from directly above (λ = 626 nm), what is the minimum possible thickness of the film? Homework Equations 2nt = (m+0.5)λ t = (m+0.5)λ/2n The Attempt at a...

Hi there, I am preparing to use the scotch tape method to get hex-Boron Nitride thin film from hBN powder. As far as I know, the available particle size for hBN is 10 um at most, is it possible for me to get hBN thin film using the peel off method with size larger than 10 um? If so, what is the...

Another grad student and I have figured out a way to create micron-sized channels INSIDE a piece of thermoplastic polymer using a laser. Basically it creates a porous channel inside the material (I attached a microscope image). This is a long channel but the inside of it is not empty - it has a...

I am trying to use a metal film resistor to limit the current inside a dilution fridge (to reduce noise power from it), but I couldn't confirm if the metal film resistor is going to survive (or it goes superconducting) at ~3 Kelvin, searching a bit on the web but still I couldn't find the...

Hi there, Does anyone know if there is any method to measure the out-of-plane thermal conductivity of a suspended thin film? As the conventional way of measuring the out-of-plane thermal conductivity is to deposit the thin film on a thick substrate, but we want it suspended. Thanks in advance.

Is there any program can estimate the thickness of thin film using transmittance and reflectance data ?

Homework Statement A coating of n1 = 1.27 material is to be added to n2 = 1.50 glass, in order to make it "irridescent." a) What is the thinnest layer of material which will have a reflection maximum for normal-incidence light at BOTH 400 and 600 nm (vacuum) wavelength? b) This thickness will...

Homework Statement Monochromatic laser light is shown through a double-slit apparatus with a slit separation of onto a screen, but no interference pattern is seen because the thin transparent coating (index of refraction n=1.35) on the screen is creating a thin-film destructive interference...

Which do you believe is the best choice for a low temperature RF heating susceptor, i.e. - greatest rise in temperature vs. field strength. I am aware that Graphite (expanded graphite foil) has excellent thermal conductance in plane and therefore makes for very even heating patterns over large...

Hi, I actually have two questions that are somewhat related so I am including them in one post. I add much more detail about the system then probably necessary because I'd like to see if I have a correct understanding of how the system works in addition to the question itself. Please bear with...

I want to deposit a layer of indium with a thickness of 10-100 microns on a metal bar. What would be cheap method for prototyping this? I am considering either soldering the indium and then flattening it or using an electron evaporator beam. Any other suggestions?

Hi, i am wondering how do you calculate the minimum film thickness between two plates, one smooth surface and another surface with a square microasperity. i am just very confused as to how do you determine the film thickness in between them. I have attached a paper which has a graph on...

A little "magic" trick with polarized film DO try this at home! I took three pieces of polarized film (which I salvaged from a pair of 3-D glasses). First I put two pieces together (A and B), one rotated at 90 degrees to the other. This effectively blocks out almost all the light. Then, I took...