Metal Definition and 999 Threads

Hi All! Haven't been here for some time, the changes are looking good! Anyway, formalities aside, I am having serious problems sourcing and implementing a suitable stainless steel (Grade: 304; thickness: 0.3mm) substrate for my etching process. I'm currently working on developing a...

Because China has flooded the market with cheap metal scrap dealers can no longer make money off of ferrous metals, so what now, what can one do with the tones of metal scrap?

I almost "get" it, but not quite. Can someone help? Here is my current understanding. Say you solve the Kronig-Penny model. You find that you get bands of N closely spaced energy levels, with large gaps between them. Under normal conditions, electrons fill the band to some level (let's say we...

We know that lithium, sodium and potassium tarnish when exposed to air, but rubidium and cesium catch on fire. Why is there such a huge jump in reactivity between Rb and K?

Homework Statement the metal rod is supported by another metal rod at one end . The metal rod is supported by another metal rod at the end. so , the direction of tension of metal rod is acted upward , right ?( this is the initial prediction) But , i was told that the tension that we get from...

Homework Statement earlier today i was doing some coursework to find the specific heat capacity of an unknown metal by submersing 100g / 0.1kg of the metal in boiling water above 75°C and record the temperature after 30 seconds (θm). we then had to transfer the the metal from the boiling water...

Hi folks, Just wondering if anyone can help with a few questions I have. I'm working on a design of a gate which, instead of using a traditional hinge system, will consist of an outer cylindrical post with the gate leaf welded directly onto it, and an inner cylindrical post which will bear the...

Homework Statement Find the potential outside a charged metal sphere (charge Q, radius R) placed in an otherwise uniform electric field E0. Explain clearly where you are setting the zero of potential. 2. The attempt at a solution So for this problem I figured I could exploit superposition and...

i am wondering would that be possible to make a prince rupert's drop with metal.. would it end up having similar properties? (ie high compressive stress => stronger) or does molten metal flow too quickly?

I want to know the force required to bend a piece of sheet metal in a hand bending brake. The sheet metal is clamped down and then bent upwards to a desired angle. The action is performed in the video below . Let's say I wanted to bend a piece of .032" thick AL 3' long to 110° (given the brake...

Its given in my book that Sulphuric acid displaces more volatile acid from Metal salts like NaCl. That is, NaCl + H2SO4→ HCl + Na2SO4 What does valtility have to do with such reactions? Or Should I just accept it as a fact?

When a muon ( with energy around 1 GeV ) pass through a metal, such as Iron, which is about 1 mm in the z direction, how many energy the muon will lose ? Is there any formula to use?

Hello, I am a last year mechanical engineer student in Marocco, and i have no idea to solve a problem with my final year project, since we have never studied a thing about Metal fabrication. The question is " give one method the Cone Deck could be formed in mass production assuming that flat...

Hi What is more beneficial as a graduate course? Functional Ceramics vs Principles of Metal Forming? Please tell me what you think Thanks a lot

I guess the question is also when. If you have some food or liquid to store. If you use a low quality cooler bag with 200mL to 300mL Ice pack at what point will a Vacuum seal with no Ice beat the cooler bag? I guess at the 10 hour mark or 24 hour mark or at some very long period of time.

My project involves making a 5 ft*3 ft*4 ft (l*b*h) aluminium/stainless steel sheet metal box at the back of a slow moving pedal vehicle. There is no load on the sheet metal, except from small vibrations from road travel. My question is: 1. What gauge of sheet metal thickness would be enough...

Let's assume for a minute that money was of no concern. If one has a 10 MPa external environment and needs to have vacuumed-out spheres (or 1 atmosphere, close enough to call vacuum) inside of that environment. In particular, I was thinking of a sandwiched lattice of maraging steel, with it's...

Homework Statement I have 1.5 kgs of silicon with temperature 40 degrees celsius. It is dropped into 3 kgs of water holding temperature 25 degrees celsius. The system is heat isolated from the environment and the final temperature of the system is 26.2 degrees celsius. I need to find the...

In gold leaf electroscope from the following video I have a doubt From time 2:11 to 2:14 flow of negative charge i.e flow of electron won't it cause current?

Hello, How do I take into account the difference in stiffness when fabricating a part (for example, an L-bracket) from sheet metal or using an extrusion? In particular, where I work, it is "common knowledge" that extrusions are stiffer. How do i factor this in the stress and strain...

I was reading about semiconductor transparent conducting oxides and I found this why p-type conductivity is limited in TCOs. But I could not understand its meaning please someone explain me how the holes are localized at valance band edge and how dominated by oxygen- 2p levels? ''Owing to the...

Homework Statement Two conductive metal plates are bonded together. Upon bonding, an oxide layer forms between them. The oxide layer is negligible thus the overall resistance of the plates is small. However I am having trouble finding this overall resistance, i.e., trying to find Cp and Rp...

Homework Statement What is the maximum mass of lead you could melt with 2000 J of heat, starting from 25 ∘C ? Lead melts at 328∘C , its specific heat is 128 J/(kg⋅K) , and its heat of fusion is 2.5×10^4 J/kg . Homework Equations Need to find both the mass in the heat of transformation (Q =...

It has been my understanding when working with natural wood beams/joists, that for example, two 2x12 members over a 12' span gain significant strength when they are fastened (nailed, glued or both) together rather than just lying side by side touching one another. Is this phenomenon...

Obviously there are MANY differences, but I'm curious about one in particular. In an article I read, the creator used NiMH batteries because of their high charge density, but also because they do not require a charge controller and voltage regulator in the circuitry. Why is this, and is there...

Let's say you have a small metal case that is 3 inches by 3 inches versus 2 inches by 2 inches. Inside at center is a heat generating source (let's say a small processor chip). How efficient is the transfer of heat from the processor to the air... and from air to metal between the 2 different...

That's pretty much it. Why do they have 0 Oxidation state?

So i have this simple situation where i have an electron beam with a certain kinetic energy, and i have a metal plate connected to the ground, and the electrons hit the plate, now i want to know the voltage of the current in the wire to the ground. Now i know both kinetic energy of the electrons...

Why can not the density of states of a metal at Fermi level be zero? Thanks!

I've put a small battery powered commercial radio inside a Quality Street tin. The tin is all metal with rolled joints and the lid is a tight fit. I'd be willing to bet that there are no holes greater than 0.1mm around the lid's closure. Why does the radio work when receiving an AM station (1...

I need to be able to support a variable side load up to a maximum of about 250lbs at 10' high. I am planning on using a 14' 4x4 steel pole that will be anchored 4ft in the ground (with concrete). Question I have will 4x4 square pole be good for this application, and would 1/4" thickness...

How can I calculate the maximum load a shelf made from sheet metal can take at a certain deflection limit? Have a number of different sizes and gauges and need to calculate without testing. Any help is much appreciated. The shelf is supported in the 4 corners similar to photo below...

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...

Electrons pile up inside a metal up to a maximum value in k-space (meaning the have velocity) and occupying all levels at 0K, solving the Schroedinger equation as running waves. So electrons moving => radiation being emitted. But electrons can't move to a lower energy state, so that would mean...

So, I'm new around here and I'm not entirely sure if this is in the right section, but today I noticed something which I found thought-provoking. Before I go into this, I should point out that I'm 16, so all of my physics knowledge above high-school level is entirely self-taught, so I still have...

Homework Statement Homework Equations I have some equations relating B to I but I don't really know if they are useful The Attempt at a Solution I actually don't even know where to begin on this, my notes are confusing and vague :(

These are questions I've made up to try and wrap my head around the topic, so the theory within the questions themselves might be flawed. 1. Homework Statement There are a number of metal sheets that are similar in every way except they each have slightly different masses. The temperature of...

Homework Statement Homework Equations ΔL = α L0 ΔT The Attempt at a Solution I converted the 0.62 mm to meters, giving 0.00062 m am I suppose to convert the degrees from Celsius to K? why is the coefficient for steel in K-1? What does that even mean? anyway, I converted C to K and answer I...

Homework Statement Four identical parallel metal plates with area $$S$$ and distance between each two $$d$$ are located in air. The external plates are connected by wire. What is the equivalent capacitance between A and B? This is problem from Irodov.Homework Equations $$q=UC$$[/B]The Attempt...

Hello everyone, thank you for helping me in the other post, this one is different but includes pressure and how to calculate how much of it is present when an object is being "indented" or dug into. I come from a forum that discusses fictional characters a lot and we find it highly enjoyable to...

Homework Statement How much work would be required to remove a metal sheet from between the plates of a capacitor, assuming a) the battery remains connected so the voltage remains constant b) the battery is disconnected so the charge remains constantHomework Equations When a metal sheet with...

Hi All, Lets assume, we have piece of cubic copper of side length 1 cm metal with neutral charge, so: 1) The free electrons in this piece of copper exist everywhere as waves? , each electron with its quantum state. 2) On applying an external electric field the wave-function collapse and they...

Is there any way (ex. MO theory, valence electrons, etc) to determine the coordination number of a metal ion with another ion? I know it is generally a multiple of the oxidation number of the metal ion. However, for something like Ni and NH3. how would I know that it's a coordination number of 6?

Homework Statement When the supply of oxygen is limited, iron metal reacts with oxygen to produce a mixture of FeO and Fe2O3. In a certain experiment, 20.00 g iron metal was reacted with 11.20 g oxygen gas. After the experiment, the iron was totally consumed, and 3.24 g oxygen gas remained...

Homework Statement [/B] A simple model of a railgun is a metal bar which runs on two long parallel rails. The two rails are connected to a charged capacitor with capacitance C and a resistor with resistance R. After charging, the capacitor can discharge through the circuit. You may assume that...

When a metal (electrode) is in contact with water, an equilibrium forms: Mg ⇔Mg2++e- Adding more of the metal Mg should convert some of it into more electrons so that the ratio of Mg to Mg2+ remains the same (as the equilibrium requires). Therefore twice the amount of metal in contact with water...

The atoms in a metal (ex. Cu) are arranged as a 3-D grating. But to our common sense ,smooth metal surfaces only reflect lights. Why can't we see diffraction from metal surfaces?

Hi Forum, Couple of pheromone here: Metal reflects EM waves (visible light and lower) Antenna absorbs EM waves electrical circuit reflects high frequency signals inside the circuit electrical wire with the right length and right signal becomes an open-circuit/Antenna I think my question is...

Hey Given the simple electric circuit below, the connection between the negative end of the DC source and the load (R1) is a pipe where heavy oil flow with some H2S and CO2. The pipe is made of iron and copper alloy. Without the DC current, H2S and CO2 will corrode the pipe. After introducing...

In stories regarding the "Roswell UFO crash", there are claims of alien metal foil that (depending on who you ask! :) ) you couldn't cut with a knife, couldn't tear it by hand, and which you could crumple up, and when released from your hand, it would unfold again to a nice, smooth sheet. Now...