Materials Definition and 989 Threads

Hello, In the framework of an academic study, I am reviewing the oxidation methods of III-V materials for optronic applications. What are the best techniques to oxidize III-V materials such as InP, AsGa, or InSb in order to have a good quality oxide layer of about thirty nanometers? The oxide...

Hello I'm teaching assistant at one university in Bosnia and Herzegovina (department for computer science) and I have recently been chosen to be an assistant at "Introduction to computer algorithms" subject. First few classes are based on mathematical background (induction, recursion, algorithm...

I want to make fiber optics from seaweed or jelly.. It will be happen? Please give me the literature or journal.. Thank you very much for helping me.. :)

Hello, I am currently a chemistry student and will be graduating this Spring. I have applied to a couple of schools and have been accepted to one school so far for a PhD in Materials Science and Engineering. I am worried that a PhD is overkill. Long term I want to work in industry. I would like...

So I learned today about the version of Ohm's law where J = \sigma E and my professor mentioned that some materials (non-Ohmic materials like superconductors) have "vanishingly small" extra terms that are quadratic or cubic. I'm wondering if anyone can direct me to a source (or even just...

Hello, Is "Nuclear Materials" an area with good expectations? I know that materials are very important for nuclear civil: reactors lifetime, safety and performance, but I'm not sure to what point this a good prospects subject, when compared with other nuclear related domaines (safety, radiation...

hello which is the lightest material that electromagnetism can set it in motion? thanks!

Hi, I had a question about p-n junctions. I've only recently started to learn these concepts so there may be flaws in my thinking (please feel free to correct me). What I'm understanding is that for a p-n junction to function properly and produce a current when connected with a load across the...

Hello all, I want to know that refractive index of materials like cooper, zinc, aluminium, teflon, PMMA varies with the application of heat from room to 100°C and for negative temperatures 77k to 300k. thanks in advance.

I live in the United States, have a BA in physics, am working for a materials company, and am about to apply to grad school. Can anyone weigh in as to which degree, a master of engineering or a materials science and engineering MS, is more marketable? Both subjects interest me equally. I am...

Plastic materials are said to have large gaps between the valence band and the conduction band. But what is its valence band properties? Why do plastic melt easily compared to the glass? What is the relationship between energy bands and melting? And what are the right words in goggling this...

Hello .. This is part of a bigger project, what i need basically is a small and light sensor (programmable if possible) to be attached to a flying drone, the drone has to be able to detect tin cans from a distance - soft drink cans for example?

I would like to know what is the difference between a solid state physicist and a materials engineer. I mean, do they end up doing the same kind of job or research? If they both have the same purpose, how can they do it having different backgrounds? Which preparation is better for the purpose?

1. To carry out a materials selection exercise for a military/surveillance portable infrared imager tripod. The exercise will be carried out by means of any legal and valid technique possible and applicable, including (but not withstanding) techniques described in lectures, textbooks &...

Dear Friends Could anyone tell me whether we can stich (or) Join Magnets with Non Magnetic Materials? Is there any Possibilities? Thanks for Your Replies in Advance

I know that the refractive index is determined by a material's dielectric constant and magnetic permeability. It's also true that we can treat the refractive index as a complex function with the imaginary part giving you an absorption spectrum. You can then get the index of refraction from...

Hi Does anybody know of a good book, or, preferably, a good website, on the chemistry and physics of energy sources (solar panels, chemical reaction and role of syngas, electrolysis of hydrogen and the like)? Also, a link to a website which covers physical properties of materials would also be...

Hi Guys, i need your help, where can i download free articles about the band gap of semiconductor materials (like copper (II) oxide). don't mention sciencedirect and arxiv, because i already explore that, and they provide limited research articles. thank you.

Homework Statement Two identical sized specimens of materials A and B are made from materials which produce stress v strain graphs as shown below. The specimens are arranged in a press, the press moves uniformly, which of the specimens would be under the greatest stress? Homework Equations...

Dear Friends, I am working on a project in which we need to shield an electrical field with a heavy 1 MHz component, at the same time, sparing the magnetic field as much as we can. With our limited knowledge, we came to the conclusion that a material with 10 kOhm conductivity would do this...

Dear all, I'm a university student in charge of developing a biochemical device (reactor) for the depuration of leather factory wastewaters, this is an european project leaded by Ambiental Engineering University of Florence. Part of this device should be colonized with fungi in order to purify...

Homework Statement You are considering two different designs for a walking cane. Both designs use hollow metal tubes, but design A has a circular cross section (outer diameter h) whereas design B has a square cross section (outer width and length h). Both canes are designed to withstand an end...

Hi. I'm looking for a recommendation for a book (or website) that has detailed information on properties of materials. Specifically on mechanical properties. A book that covers all grades of materials, not just a general guide. I'm forever to-ing and fro-ing between websites, datasheets and my...

In case of ductile materials we know that there is a substantial difference between the ultimate tensile strength and yield strength. As long as the specimen stress is below the yield strength we need not worry about engineering stress and true stress, as they as essentially same. But when...

I seek to build a vacuum chamber for shipping radon contamination sensitive samples. The cylinder will have a height of approximately 2 inches, and needs an inner diameter of 10 inches. The plan is to weld stainless steel pipe to a plate on the bottom, and to have a lid bolt on to the pipe with...

Hi all, I'm wondering if anyone knows of a way to obtain elasticity properties (Ex, Ey, Ez, Gxy, Gxz, Gyz, vxy, vxz, vyz) from the terms of a 6x6 anisotropic stiffness or compliance matrix. I'm looking for a closed form solution, preferably. I would think that there should be a closed form...

Long post, read the TL;DR if you please! Hi everybody, first post here. Probably should have asked this much earlier, but I didn't find this site till just a few minutes ago. I'm a senior studying materials science and engineering, I'm planning to stay another year for a master's degree in...

Specifically, my school offers a physics b.s. with specialization in materials physics. right now i am listed as just a physics major but recently i have been considering most likely not going to grad school. If I want to go straight into the workforce in industry would a specialized degree be...

Does anyone know of a class or a textbook or anywhere to start doing research on how to start off with a set of desired properties of a material and begin designing that material from a molecular level. A for instance would be say you want a material that is capable to separating oxygen from...

I am an student of Materials engineering I'm 4th semester. I have always wanted to develop airplanes (I grew up close to an airport). I know for some articles on internet that Mechanical engineering is closely related to aerospace engineering. Over the 4th semesters in materials engineering I...

Homework Statement A long circular steel tube having a mean diameter of 254 mm and 3.2 mm wall thickness is subjected to an internal pressure of 4.83 MPa. The ends of the tube are closed. The yield stress of the steel is 227 MPa. Find the additional axial tensile load F which is needed to...

Looking for some information on how a shrink fit collar actually works. I get the basic principle that you heat it, it expands, fit the collar, let it cool and it contracts and grips as a collar. However, if you heat a material am I right in saying that it expands in all direction. If this is...

Hello everyone. I'm not entirely sure if this is the right section to post this question in but if it isn't, then I apologize. I'm studying for a test in E&M and I've come across a topic that had me thinking and I'm not quite sure if the explanation I'm thinking of is entirely true. Please...

Would anyone here have an opinion on whether either of these MSc courses is better to have when looking for employment later? I'll already have a BSc Physics. 1) MSc Materials Science (at a much better ranked university than below, and includes some programming) 2) MSc Advanced Composites &...

A 1-ton wall hoist consists of a horizontal beam, supported by a tension rod at 30 deg, as shown. The rod is to be designed with a factor of safety 5 with repeat to its yield point of 30,000 PSI. Determine its necessary cross section S=F/A 30000/5=6000PSI -2000+Rsin(30)=0...

Say you have a paramagnetic (or diamagnetic) sphere (or some other shape) and you apply a field of H = 10 Oe. Now, we have H=(1/\mu)B-M. That would indicate that outside of the material, B and H are essentially the same, right? B = 10 Gauss, outside of the material. But shouldn't the...

sufficient enough to redirect/shield against ultrasound 1MHz being directed through the air. i know a vacuum would. What I'm questioning is if you had 2 layers of different materials stacked on top of each other what could prevent the ultrasound from reaching the 2nd layer assuming the 1st layer...

Homework Statement A uniform bar of length 2l is rotated in a horizontal plane about its mid-point as center with an angular velocity ω. This case must be reduced to a problem in statics by the application of d'Alembert's principle, the "forces" acting being "centrifugal" forces. a) Plot...

Hi everyone, I've got an idea I'm trying to work out but I'm having trouble finding out about a few things. Firstly, what material or metals have the highest ambient temperature? I know uranium is kind of warm but is there any material that is just warm or hot? And how hot can it get? Thanks guys!

A propeller shaft in the largest and most powerful ships transmits about 50,000 hp (1HP=33,000 ft*lb/min). Assume that the propeller transforms this power into a forward push on the ship with an efficiency of 70 per cent and that the ship's speed then is 30 knots (1 knot is 6,080 ft/hr). The...

I often enjoyed how when you shape an object with clay and blast it with a furnace, you would be able to turn the soft material into one where you can store water and heavy objects inside, and be resistant to some external forces as well. Thus, it make me wonder if there are materials that...

I understand that the dynamic modulus of a material is measured by inducing a sinusoidal force and measuring the strain response. Usually one gets a value for the storage and loss modulus. However, I don't understand how one would "quantify" how viscous a material is. I know a viscous material...

Hi all, I've recently learned some details about refractive indices in different media that I never knew about before. Up until now, I was aware that the speed light travels in a certain medium is dependent on the wavelength of light used. However I wasn't aware that for different kinds of...

I have a heavy apparatus I am working on which needs to be mounted onto a plate (or some other support structure). The plate material has to be high strength, light-weight, and display very weak magnetic properties. Any suggestions for a material? Thank you.

Good evening guys, next period I'm going to take Calculus II at the University, but turns out that in my university they split it in Calculus II-A and II-B. The topics covered in each are basically those: Calculus II-A: Definite Integral, Techniques of integration, Improper integrals, first...

I understand that, for example, a thick enough sheet of lead can absorb gamma radiation, but I want to understand what actually happens at the molecular/atomic/subatomic level. Also, can the same logic be applied to cosmic particles? I have tried Googling for an answer, but to no avail. Can...

Homework Statement Question is attached Homework Equations σ(x) = 0 σ(y)= P/A t(xy)= Tc/j The Attempt at a Solution I know how to do the stress transformation, but my only issue is noticing why σ(x)= 0, I can't see it, can someone help me.

Hello, I need some help trying to decide my future degree. Any comments would be appreciated! My History: I want to dedicate my career innovating Electrochemical technologies (Fuel Cells, Batteries, Solar Cells, etc...). Before entering college, I originally applied as a "Chemical...

Homework Statement Find the equilibrium separation between Diamond and Copper materials. Homework Equations Lennard-Jones force/unit area: p_a(z)=\frac{8w}{3z_0}\left[\left(\frac{z}{z_0}\right)^{-9}-\left(\frac{z}{z_0}\right)^{-3}\right] I need to find z_0 which is the equilibrium...

First, hopefully this is in the right section. So I am looking for the best way to prepare for the new FE Mechanical exam. I know that the format changed in January 2014 so I am having a hard time finding the best books and study materials for this new format. In Google searches results come up...