Material Definition and 1000 Threads

A material is a substance or mixture of substances that constitutes an object. Materials can be pure or impure, living or non-living matter. Materials can be classified based on their physical and chemical properties, or on their geological origin or biological function. Materials science is the study of materials and their applications.
Raw materials can be processed in different ways to influence their properties, by purification, shaping or the introduction of other materials. New materials can be produced from raw materials by synthesis.
In industry, materials are inputs to manufacturing processes to produce products or more complex materials.

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  1. L

    Wool Material Shrinking from Heat

    I have a hat, made from what I believe is rabbit hair (not leather, just the hair). I sometimes leave it in the car. I have noticed that if I leave it in the car for a long period, when it is hot, the hat shrinks. I have 2 questions. A. Why does this shrinking happen? B. Is there any way to...
  2. L

    Finding a Material to Reflect Radio Waves

    i was trying to look for which forum to put this in so sorry if its in the wrong one. :D Im working on a project and i need a material that is able to reflect radio waves, like a mirror reflects light. any ideas for which material will reflect?
  3. M

    Calculating Heat Flow Through a Block of Material

    Homework Statement A block of material with a cross sectional area of 15cm^2 and length of 8cm is at hand. A temperature difference of 30degrees is established and maintained across the block. Find the rate of heat flow through it if the material is wood (K = 0.08Js-1m-1C-1) Homework...
  4. A

    When will a material burn if a laser is shone on it?

    Hi there, This may sound like a silly question, but I'm looking at shining a high power laser onto a target material for a fixed period of time. I have modeled Alumina in Ansys Icepak, and the temperature increase has come to 4700 degrees C. This maximum temperature is only reached for...
  5. S

    Can Static Toughness Data Accurately Predict Impact Load Failures?

    let me explain i do a static tensile test and get the stress strain graph. the area under the graph is the toughness that means i can use this static toughness data to predict the failure under impact loads other idea is that i have done a impact toughess test. if i can get the...
  6. E

    Need reference for material properties

    I am an electrical engineer and not familiar with this. I need to look up the permittivity and conductivity, density and acoustic speed of some common fluids: sea water, de-ionized water, castor oil, alchohol, ... Where would I find some reference containing these numbers? Thank you.
  7. S

    Finding damping coefficient of material

    i have found the damping factor of a plate from experimental vibration. how can i find the damping coefficient of the material of the plate
  8. E

    Calculate deflection with a varying inertia and material beam

    I have an application where I have a shaft being supported from end to end with bearings (self aligning) and a motor hard mounted driving it. The shaft starts at 1 3/4" RD to accept motor and bearings. Then is welded to a 2" x 1/4" square tube for the output. It allows for a wooden roller to be...
  9. C

    Corrosion-Resistant Alloys for Nuclear Reactors

    What is the most corrosion resistant alloy other than Zirconium and SS that could be used in reactors but it is not economical?
  10. G

    Reading material for Physics Undergrad Student

    Hi, I'll be starting a physics major in the fall at university. I was wondering, is there any good reading material I can get my hands on so I can start learning now? Thanks.
  11. G

    Checking Material Indices for Strength & Fracture Resistance

    I'm currently doing a project in my materials class and I wanted to check if these two material indices were right. The objectives are: 1. The material must not fracture 2. The material must be strong (no deformations) Material Index 1 ------------------------ Considering a yield-before-break...
  12. N

    Material selection for sour/acidic service

    I am facing some problems regarding material selection for sour/acidic service of raw natural gas due to the presence of H2S & CO2 gas. According to the common practice if the raw gas contains <4 ppmv H2S & <6 mol% CO2 then we consider this as a sweet service and we can use carbon steel...
  13. R

    What determines the refractive index of a material?

    1- what determines the refractive index of a material? i understand that it is ratio between velocities in vacuum and medium but i want to know about complex refractive index which also accompanies extinction co-efficient. my explanation is that bent and slowing down of light depends on crystal...
  14. B

    Speed of light in refractive material

    i understand that the speed of light slows down in a nmaterial with a refractive index greater than one when compared to a vacuum, but is this merely the speed rather than the velocity decreasing, ie does time actually pass slower? i suppose what i would really like to understand is the...
  15. T

    Need material to study Galois theory

    I would like to study Galois theory by myself (I've already studied group theory). Can anyone suggest any good video lecture or pdf available on the web? thank you in advance
  16. russ_watters

    News Blockade Runners Provide Material Support for Terrorists

    http://www.usatoday.com/news/washington/judicial/2010-06-21-supreme-court-anti-terror_N.htm Interestingly, this case was argued by the Solicitor General, Elena Kagan, who argued: http://www.usatoday.com/news/washington/judicial/2010-02-23-terrorism-law-appeal_N.htm?csp=obinsite The logic...
  17. D

    Good books for material science and metallurgy

    can you please suggest me good books for material science and metallurgy
  18. H

    Courses Style of learning course material

    Hi, I was wondering how you guys read from a book. Let me be clearer. When reading a paragraph in a book, do you read very slowly with full concentration until you understand every fact in that segment and make relevant notes, or do you read the material a few times, understand all (or...
  19. R

    What makes a semiconducting material a semiconductor?

    what really makes a semiconductor? Is it just the presence of a band gap but then insulators and metals also have band gaps or carrier concentration? Or we need to perform Hall measurements and also need to study I-V characteristics? Or do we need all of these parameters to establish a material...
  20. S

    Magnetic field through ferrous material and across air gap

    I am attempting to determine how strong a magnetic field will be on the other side of a thick material and then across an air gap. For instance, I have a closed steel cylinder with a steel piston inside it. I plan to affix a permanent magnet to one side of the piston (inside the cylinder)...
  21. N

    Bottom of bolt head compressing against the material it is holding

    Hi guys, If you look at the picture I have included, where a bolt is forced in compression against the plate it is holding, to which example from Roark's would this condition be? (i.e. annular plate with a uniform annular line load, outer edge free; inner edge guided... etc?) I am trying...
  22. H

    Constructive Proof of Material Implication

    Hi, I'm struggling to find a constructive proof (through natural deduction) of the material implication replacement rule (i.e., that (a => b) <=> (~a \/ b). I believe the only possible way would be through contradiction, but I can't seem to get to it. Is it even possible? Thx.
  23. S

    Piping material specifications (PMs)

    Dear Engineers I am very curious to know about Piping material specifications (PMs) . How can I select the appropriate material for components which is used in piping? For example we use A106 Gr B for vapour pipes or A105 for flanges and A105/A234 for fittings less/bigger than 2". Now I want...
  24. M

    The Black Box that is counting (ADV MATERIAL)

    So I am taking intro to stats and probability and I am having trouble understanding something that may be quite difficult to explain in counting. Let me start by telling you what i understand The choose function i.e (6 C 2) will take six elements and create a SET of 15 TUPLE's, in which...
  25. C

    Material Derivative: Show F(x,y,z,t) Moves with Fluid

    A fluid moves so that its velocity is \vec {u} \equiv (2xt,-yt,-zt) , written in rectangular Cartesian coordinates. Show that the surface F(x,y,z,t) = x^2exp (-2t^2)+(y^2+2z^2)exp(t^2)=constant moves with the fluid (so that it always contains the same fluid particles; that is, DF/Dt=0)...
  26. S

    Piping material specification(PMS)

    Dear Engineers I am very curious to know about Piping material specifications (PMs) . How can I select the appropriate material for components which is used in piping? For example we use A106 Gr B for vapour pipes or A105 for flanges and A105/A234 for fittings less/bigger than 2". Now I want...
  27. E

    Best material to replace plastics

    Plastics is one of the widely used material in the modern world. Almost all the items that we use today are made up of plastics. It is also a major contributor to environmental pollution. Which is the best material that can replace plastics? Ethan
  28. G

    Looking For A Solid Material Light Diffuser - Terminology?

    I'm looking for a solid material that will diffuse light throughout it. In particular I would need a thin bar with a light source at one end that will diffuse light to all sides of the bar, however, I don't specifically need a bar as long as the material can be machined. I'm trying to search...
  29. I

    Energy Lost when Steel Sphere collides with a soft plate of material

    Hi everyone. This isn't a homework question; just something I was thinking about and would like some advice on how I should tackle it. Homework Statement How can I approximate the Kinetic Energy Lost of a Steel Sphere when it collides with a soft sheet of material. A solid steel sphere of...
  30. C

    Difference between Material dispersion and waveguide dispersion?

    Can someone please explain the difference between Material dispersion and waveguide dispersion?
  31. C

    Understanding Material: Deriving Equations and Applying to Problems

    Hey all, I need a little advice. Are we suppose to derive equations in order to lead to understanding of the material? What is the point of deriving equations? Should I instead read the material first and see how it applies to the problems? I don't do any of this and maybe that's why i have...
  32. J

    Exploring Material Engineering for Renewable Energy and Medical Applications

    hi, i have decided that i want to do research into ; quantum computer (if quantum computer are invented by the time i graduate ) then nanocomputer/nanorobotics more specifically their application in oncology and drug delivery renewable sources of energy ( if possible ) open a...
  33. R

    Calculation of material properties in transformation media

    Hi everybody, I'm focusing on meta-materials. I have recently read Schurig's paper "http://www.opticsinfobase.org/oe/abstract.cfm?URI=OPEX-14-21-9794"). In the article, the components of the permittivity tensor are given by \varepsilon^{i'j'} = \left|\rm{det}(\Lambda^{i'}_{i})\right|^{-1}...
  34. J

    Speed of sound in material under tension

    I have built a loading machine for testing material properties. It applies tension at slow rates (ie 1htz) under load control until the specimen fails. One thing I noticed is that if I tap the material as it is loaded, it seems to give off a different pitch noise when it is under higher tension...
  35. K

    Questions on material engineering

    i am really wondering does Material engineering has a future. I am wondering this as my friends made a few comments on this subject and i am currently very confuse 1. People who study Material Engineering will most likely very difficult to get a job or the job will be related to radioactive...
  36. A

    Material that is bendable in certain conditions

    Hello everybody, This is just a general question I have, and probably the title did a very bad job at explaining it, so here it goes. Is there any material that is available, or even if its still in research (as long as you have some links), that bends/flexes or contracts in certain...
  37. A

    Absorbing Material Over a Slit in Deriving Double Slit Fraunhofer Interfernce Pattern

    In class we have been deriving the Fraunhofer interference pattern for a double slit experiment. I now have a question of having to derive it if one of the slits is covered with an absorbing material. I have got the equation out but I am missing a constant K... Homework Statement We have two...
  38. S

    Can a dielectic MATERIAL IS A INSULATOR?

    When a dielectric material insert between two plate capacitors the conductivity may increase. Normally we talk that a dielectric is insulator?but how can it increases conductivity?
  39. 0

    Calculating Chromatic Aberration in Dense Flint Lenses: A Homework Solution

    Homework Statement The refractive index of a material is different for different wavelengths and colours of light. For most materials in the visible range of the electromagnetic spectrum, shorter wavelengths have larger refractive index compared to longer wavelengths. The effect of...
  40. R

    Why Does Failure Stress Depend on Material?

    why failure stress depend upon material instead of size and shape?
  41. R

    Dielectric Material in a Capacitor

    Can anyone explain the concepts behind dielectric material inside a capacitor. Why is the capacitor able to store more charge exactly? Thanks!
  42. S

    How Do You Calculate the Required Thickness of Aluminum for a Box?

    Homework Statement i am trying to work out the required material thickness for a given box. the material i am using is aluminium. i only require the formula - can't find a suitable one on web Homework Equations The Attempt at a Solution M = I σ y M = bd M...
  43. R

    What is the best plastic for injection molding with high gloss and flexibility?

    Looking for a flexible plastic, equivalent to TPE shore A 50-60. Finish to be similar to ABS or PC, which mean high gloss, polish finish; that can be injection molded. Can somebody recommend a plastic resin that meet those criteria? -robert
  44. S

    Watertight and low wight material

    In my project i have solar cells we use are called B50 cells with an efficiency of 21%. Since the cells come in contact with water we are looking for a cover material that is first of all watertight and secondly it should influence the performance as less as possible. Last but not least the...
  45. S

    Question about tension and deflection (Mechanics of Material)

    Hello everyone, I have some difficulties to solve this question in my homework. Homework Statement Picture http://img714.imageshack.us/img714/7953/picz.png Rigid bar ACE connected to rod AB, CD, EF which have same material and surface area A. Calculate tension caused by force P in...
  46. S

    Particular material that becomes strained under electrostatic

    I am currently looking for a particular material that becomes strained under electrostatic or magnetic fields. I am new to the world of solid state physics and I was interested on doing a research project on the studies of the electrostriction effect. Thank You
  47. A

    Strength of material, how to know it is compressio or tension?

    Homework Statement May i know how to know boom and rod, which is in tension and compression? http://img7.imageshack.us/img7/5728/16203309.gif http://img7.imageshack.us/img7/2595/57134603.gif Homework Equations The Attempt at a Solution
  48. G

    English vs French Book Versions: Added Material or Type Set?

    The english version of this book has almost 50 pages more than the french one. Added material or just different type set?
  49. A

    B, H fields due to a magnetized material everywhere

    If we consider a material with uniform magnetization \vec M, what are the \vec B and \vec H fields everywhere in the magnetic material? My first inclination is to say that \vec H = 0 since there are no free currents and that therefore \vec B = \mu_0 \vec M everywhere, but I can think of...
  50. A

    The significance of material science and technology

    Hi people, Firstly I want to state that it will be my first message in this forum, I am new around here. I am studying electronical engineering, second year student. I am kind of interested in nanotechnology, hence I am trying to add the course whose name is "Material Science and Technology"...
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