Materials Definition and 919 Threads

Homework Statement Why is there such a large difference between the elastic moduli of metals and polymers? Homework Equations The Attempt at a Solution I am thinking because of the different bonding between metals and polymers. Since metals have metallic bonding and polymers...

Hello, I was wondering if anyone could point me in the direction of some quality materials science resources on the web? I am currently in an intro to materials science and engineering class and have been fascinated by the subject this semester. I was just wondering if there are any "go to"...

I have a 2 year TA offer at UC Irvine for physics (~$18k) where I would focus on Condensed Matter experiment or the chemicals and materials physics program(this program is easier and offers a 10 week summer research program before grad school begins). Degree time is usually 6-7 years. The...

The title pretty much says it all. I want to know if any piezoelectric materials can fully function in constant contact with water. If so, how long a lifetime could be expected and would there be any polluting to the water? Thanks

We are looking at designing a 10" diameter, 48" long payload shroud (Ogive nose cone) for a large hobby rocket. We have done an aeroheating analysis based on the trajectory, so we have the max temp. experienced during ascent at several body points. We want to make the shroud out of composites...

Do such materials exist? If they do, are there materials that go from very high to very low thermal conductivity depending on electrical input?

Please excuse me if this isn't a physics question - I'm not sure where it belongs. Felt, such as this: http://www.ebay.com/itm/Felt-by-the-YARD-Craft-Supplies-36-INCHES-X-36-INCHES-square-100-polyester-/261301533508 And 3mil plastic sheeting, as this...

Hello. I would like to hear of somebody with experience in the area of materials science (theoretical/computational or experimental) the answer to the following question: What kind of Physics knowledge one must have to work in this area. I mean, how much of the basic Physics stuff you must know...

I like using computations/modeling/simulation for many kinds of physical problems, whether it be for molecular dynamics simulations, CFD, DFT to determine the electronic structure and properties of materials, molecular dynamics, etc. I'm not interested in hands-on work as I hated my lab classes...

what materials heat up under pressure and for how long?? I was just wondering are there any two rocks or combination of rocks that when their flat surfaces are pushed together cause heat? If the pressure is very high is that heat quite considerable?? or maybe there are liquids that do the...

Hello all, I am looking for easy to obtain materials, preferably in powder form, with good absorbance at 808nm, 365 nm and 404 nm each (either one material for each wavelength or one for all three).However I can't seem to find absorbance charts. Does anyone have any idea either on which...

Dear experts, I wonder if semi-crystalline plastics can be considered as Mooney-Rivlin materials for an application in the analytic modeling of thin membranes. Any help will be very appreciated! The stored-energy function (W) of a Mooney material model is: W = C1(I1-3) + C2(I2-3)...

Hello all, I'm taking my first actual quantum course this semester. I went over "briefly" some quantum mechanics Fall of 2012 in a Modern Physics course during my sophomore year, currently I'm a junior. To get straight to the point, this course is making me miserable. I had high hopes for...

I intend to take the physics GRE this coming april, and will probably retake it again next year. I want to go to a good grad school, but my gpa isn't stellar (3.5ish), so in order to atone for my sins (so to speak) I want to put a lot of work into getting a stellar grade on the pGRE. However...

Hello all, I have been learning to use FDTD to model light interaction with various materials. I've successfully managed to model light interaction with semiconductors/insulators. However, I've been having trouble understanding how to incorporate metals into this model. The code becomes...

I have a basic question concerning strength and weight of materials. Please forgive me if my question is extraordinarily naive, but I'm an elderly retiree and my education is woefully lacking in this area. Thank you for your patience and understanding. Let us say we have a block of X material...

If I am using radar to determine the distance of an object from my transmission source by reflecting my radio waves off of the surface of the object and recording the time at which they return and, I want to encase my detector to protect it from the elements, how do I select the material with...

I'm hoping to make (or model) these little cells on my own, but I'm not entirely sure how it can be done with household materials. I've seen a few videos of it being done but there's not much on how to create them. Any ideas? Thanks

What are they? I am in pursuit of learning pretty well all of precalculus (algebra, trig, everything!), what are the best learning resources out there? I am studying at home by myself. Thank you, this advice could be life changing.

We all know that hard materials scratch soft materials, and the effectiveness is related to the difference in their Moh's hardness level. My question is whether some minute amount of abrasion occurs on the harder material that is scratching the soft material? If so, is there any mathematical...

Using this godawful textbook (Fundamental of Thermal-Fluid Sciences, Cengel) for Thermodynamics. It's thick as three bibles, has lots of pretty pictures, constantly goes off on tangents, avoids 'advanced' stuff like calculus like the plague and is filled to the brim with problems involving...

Hi everyone, This is my first post here, so go easy on me. :) I am looking towards investigating the properties of plasma antennas, where a plasma is created in a sealed container, and the RF signal is either capacitively or inductively coupled and the transmitted. However, I am wanting...

Can someone please give me a bit of advise. I was dealing with impact toughness of materials today, which I haven't dealt with since uni days. I was involved in charpy testing. I understand the concept of finding the impact toughness from the test [ m x g x (h2 - h1) ]. But what I can't get my...

Interstellar travel is mostly a though experiment at this stage (although NASA will be launching the solar sail SunJammer in a couple of years). My question is a very broad one about what type of materials would be well-suited for structures to support interstellar travel. Any human habitat...

What are the problems that exists in airborne structure/ circuit ? - Electronics

I'm trying to write a very, very simple heat flow simulation program. The idea is an environment space is a grid, with each grid space identical in respect to all other grid spaces (I'm calling a grid space an "element") except temperature. So, they are physically the same except temperature...

I'm working on a problem but I've hit a road block.. Then the cross section of the piece is here: The first part of the problem is to determine Iy, Iz, and Iyz of the member.. I found the y value of the centroid to be 2.8587" and the z value of the centroid to be 1.0734" using the...

Hi I chose a Monte Carlo simulation of the 2D Ising model as my Computational Physics course project. Unfortunately, I ran intro problems when formulating the exact problem since my professor probably wants me to simulate a real life material and extract magnetization curve M(T,H) out of it...

like autoignition temperature... materails will ignite spontaneous in (low pressure) with concentration oxgen and less heat temperature...

What shielding materials are best choices for reducing dose from: Neutrons: Gamma rays: Electrons: HCP: (heavy charged particles) I know, good neutron shields can be hydrogen (can be explosive though) or concrete, beta/electrons is a combo of low Z-material to block e- then high...

While thinking about the recent-ish developments in meta materials for 'cloaking' systems, a thought struck me: could a meta material or combination of meta materials (probably of a somewhat more advanced state than they currently are) be used as a form of shielding from cosmic rays of various...

I'm going to try to make this as coherent as possible. I'll start with the fundamental question first: Would it be reasonable to take classes outside the Physics undergrad curriculum/required courses that my university doesn't require, but others do? Here's the nitty-gritty: I am...

Homework Statement A. determine the deflection at point A in the X and Y direction. B. determine the maximum normal stress in the beam C. determine the maximum shear stress in the beam Homework Equations δ=(PL/EA) (possibly?) δt=αΔτL d2v/dx2 = M/EI dM/dx = V δab=δx*cosθ +...

Hello, Imagine I have an infinite wire with a DC current. Around it there two rings of ferro-magnetic material, not far from each other. Does changing the mu_r of one of the first ring, changes the magnetic field in the second ring? - If I consider just Ampére law (macroscopic...

Homework Statement A rigid weightless horizontal beam is hinged at a wall and is supported by two rods. The beam has a 8000 pound load applied at the end. Calculate the tension in each rod. The left rod is made of brass and has diameter of 1.25" and the right rod is made of aluminum and has a...

Where can i get the theoretical value of MFI for common polymeric materials such as PP, PE, PS, PMMA...as reference?

Hi, I'm using an induction coil to heat up an electrically conductive material within the coil. However, I'm worried that adjacent electrically conductive materials, which are not within the coil will also have see a heating effect, due to induction not thermal transfer. I want to avoid this as...

Hello, I'm studying machanics of materials.. I'm at the chapter that handles the angle of twist in shafts. There's one exercise that I get the most part of, but there's just a tiny part of it that I don't get! here's the exercise...

Homework Statement I have a project for my Materials Science and Engineering class and we have were given 4 unknown materials and we have to determine which kind of materials they are. We have to come up with our own experiments. As of now, I've done the Rockwell hardness test, electrical...

Hello everyone, I'm an undergraduate senior majoring in physics and math, with plans to go to grad school next year. I have two questions for you all: 1) for someone interested in nanotechnology, biotechnology, and physics, is materials science a good PhD to pursue? 2) If so, are there any...

Would a piezoelectric crystal create a negative voltage if held within a vacuum? Perhaps it's my misunderstanding of the materials properties, but it seems that if there is zero net output within the "creation"(0) atmosphere, and any slight elastic deformation shows itself in the form of an...

I’m currently working a project to produce a roadside speed camera which displays vehicle speed to drivers to improve speed awareness. A Doppler radar gun operating at 24.1GHz (1.24cm) is being used as the source and detector. There is a weather tight plastic box (opaque, at least to visible...

Hi Does anybody know how to find out the potential energy of two equally heavy, equally big and equally charged particles that are placed at the boundary layer of two different media(for example such that mercury is at the bottom and oil is on the top of both spheres( if you know the answer...

1.The center rod CD of the assembly shown in the figure is heated from T1 = 30oC to T2 = 180oC using electrical resistance heating. The two end rods AB and EF are heated from T1 = 30oC to T2 = 50oC. At the lower temperature T1, the gap between C and the rigid bar is 0.7 mm. Rods AB and EF are...

Dear all members, I just need anyone of you to verify my system and some equations I have worked out for my problem below. Please feel free to point out any flaws in my reasoning and formula applications. Problem Definition: Two flat blocks (different materials, Fiberglass and Rubber) rubbing...

Hi all, I am interested in pursuing a degree in materials engineering in order to become a materials scientist/engineer. However, I am a bit confused with the wording of some of the degrees various colleges are offering. Is there a difference between a degree in Materials Engineering and a...

I am a rising junior physics major and math minor at a small liberal arts school. I'm interested in possibly pursuing materials science for grad school (hoping to complete a PhD). However, I haven't yet taken intro-level chemistry. Originally I was planning to complete the intro sequence...

What is mean by advanced materials science and engineering

So water is completely transparent, it doesn't look darker in a glass so why when you tip it on cloth for example the cloth looks darker?

Why is it that the magnetic component of light interacts more with metamaterials than with naturally occurring materials? It would be nice to explain this in terms of inductance, permeability, and permittivity within SRR metamaterials. I'm currently an undergraduate participating in...