5
votes
Accepted
Nylon brittleness as function of moisture content
Nylons are a class of polymers formed from di-acid and di-amine monomers. The amine groups bond with the acid groups to form amide groups, end to end. The resulting amide groups have a positive charge ...
- 4,071
5
votes
How can I vaporize metals?
The easiest way to vaporize a metal is to create a filament of the metal. Heat the filament in the vacuum to its sublimation (vaporization) temperature. Alternatively, when the metal cannot be shaped ...
- 2,991
5
votes
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In case of solvation , Who converts gaseous ions to aqueous ? Why do we even have gaseous but not solid ions?
We define reactions uniquely depending on the reactants and products. Here are examples related to your question.
Formation: Na(s) + (1/2)Cl$_2$(g) $\rightarrow$ NaCl(s)
Lattice Formation: Na$^+$(g) + ...
- 2,991
4
votes
How the choice of etchant can affect the severity of hydrogen embrittlement during pickling and passivation?
The primary cause of hydrogen cracking is a susceptible matrix . Typically a carbon or low alloy steel that is hard ( > HRC 25) untempered is the primary problem. The martensitic chrome steels were ...
- 6,182
3
votes
is it possible to achieve 1000C temperature in a cabin?
If the heating element is constantly at 100°C, there is no way it can cause the room can get warmer than 100°C.
Otherwise, perpetual motion machines would be possible.
If you meant the heating ...
- 64
3
votes
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Is it possible to use direct air capture technology for CO2 on a non-commercial level?
It is possible and this is currently being done at the OpenAir Collective. There are two direct air carbon capture (DACC) machines under active development, Violet and Cyan. Both are small-scale, open-...
- 48
3
votes
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Help with Mass Flow Rate
It's the density calculation you have. You're almost there! This site explains it pretty well:
https://www.engineeringtoolbox.com/slurry-density-calculate-d_1188.html
Density of slurry=1/[(ratio of ...
- 523
2
votes
What's a good way to equalize pressure between 2 spaces without allowing gas exchange under normal circumstances?
There are specialty sensors and relays that are sensitive enough for the range of pressure you need, but they may be expensive.
one way is to hang the container in balance with a ballast weight to a ...
- 22.8k
2
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Are brass and copper utensils safe for humans to eat from?
It always depends on the concentration and where you place the copper within the human body.
In my opinion, the most interesting example are implants which are coated with copper and implanted ...
- 129
2
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is it possible to achieve 1000C temperature in a cabin?
To answer the question the way it's asked
heating element of sort which is providing 100°C constantly but because room is totally insulated and shut can the temperature goes upto 1000°C or not ?
...
- 1,035
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What chemical can be used to restore synthetic rubber?
The embrittlement and goop-forming reactions are fundamentally different, and different measures would be needed to deal with each.
Rubber embrittlement occurs when the rubber oxidizes, and stops ...
- 15.3k
2
votes
Can wet welding be done in mineral oil?
Mineral oil is not used to cool transformers because it is flammable. Transformer oil is a different compound which is not flammable and possesses high dielectric strength. In any case, the ...
- 15.3k
2
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Can wet welding be done in mineral oil?
No. In water welding you make steam (> hydrogen and oxygen) and conditions need to compensate for the problem of hydrogen entry in the steel. With oil you are adding the large problem of also ...
- 6,182
2
votes
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What is the field on engineering that combines chemistry and electronics together?
You could follow either Chemistry (Science), Chemical Engineering or Electrical Engineering and purse a career in Semiconductors. There are many variation in Semiconductor that fall either into ...
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How long will it take to anneal at a lower temperature?
The alloy makes a difference. If it is essentially copper and zinc like 70:30 (cartridge brass, or admiralty if you put in one pre-cent tin) or lower amounts of zinc: Nothing much happens with the ...
- 6,182
2
votes
Accepted
Balancing Equation of Octane in combustion Chamber
you also need to take into account that the complete burn for octane is:
$$2C_8H_{18} + 25\;O_2 \rightarrow 16\;CO_2 +18\;H_2O $$
Therefore $a$ should be equal to $\frac{25}{2}$.
- 24.3k
2
votes
Would the below thermal generator work properly and provide surplus energy?
Could it work? Yes. Is it practical for any scale? No.
As @DKNguyen says in their comment, if you had a free source of these components you could generate this heat and use it to do things. But it ...
- 7,148
1
vote
Accepted
Difficulty in understand the meaning of standard enthalpy of formation
I prefer this definition for Hf: "The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its ...
- 177
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vote
Specific CO2-Emissions of Natural Gas & Hydrogen Mix
assuming full combustion, CO2 coming out is
none from the H2
1:1 mole ratio from the CH4
So mass of CO2 =
( mass of CH4 ) x ( molar mass of CO2 ) / ( molar mass of CH4)
Add a slight adjustment for ...
- 1,551
1
vote
Is molecular dynamics relevant for an undergraduate Mechanical Engineering degree?
In my opinion, it is very difficult anymore to get to anything truly novel without mixing different disciplines. For example, its difficult to imagine, advances in molecular treatments, without the ...
- 24.3k
1
vote
What is the field on engineering that combines chemistry and electronics together?
Welcome to SE. Since your interest pertains to do very distinct field, I would recommend in taking one field as a major and the other as minor with key subjects you are interested in. Electro-...
- 129
1
vote
Accepted
Why do Blast Furnace flue dust generates high rates of Zn (Zinc)?
Not likely unless they use a very unusual ore. Blast furnaces generally do not use scrap. Scrap likely contains zinc ( die castings) . Electric arc remelt furnaces melt a high percentage of recycle ...
- 6,182
1
vote
What is the mechanism of adsorption-desorption on biochar obtained from slow pyrolysis/ torrefaction?
I haven't done furfural desorption from biochar, but I have done furfural desorption from metals. Here are some thoughts off the top of my head.
Regarding your question of furfural adsorption. I ...
- 131
1
vote
Why does aluminum clad steel wire have high corrosion resistance?
The dominant protection mechanism is that the aluminum excludes seawater from contact with the steel underneath, and if passivated with a layer of oxide, the corrosion rate of the aluminum via direct ...
- 15.3k
1
vote
pH calculations for boiler water
Do they provide you with the temperature of the system? In this case what they want you to do is solve first the boiler mass balance, in case there are heat/temperature specs you could make a energy ...
- 109
1
vote
Generic category of PBT thermoplastic
No . A more common polymer is polyethylene terepthalate ( PET) from which many bottles are made . I guess they would be the same group if it has a name.
- 6,182
1
vote
How can I vaporize metals?
vaporizing metal in a near-vacuum is a straightforward process; the simplest method is called sputtering and is one specific method of vacuum metallization as noted by William Hird above.
Keeping a ...
- 15.3k
1
vote
Mass balance of a recycle stream
In generel for N species you have N mass balances. So in your case 2. Also mass is conserced ( other than moles when it comes to chemical reaction). So you definitely know that the mass flow rate of Y ...
- 93
1
vote
Accepted
Calculate the radius of iridium atom, given that Ir has an FFC crystal structure, a density of 22.4 g/cm3 and atomic weight of 192.2g/mol
The radius $r$ can be calculated purely from geometry. Consider the FCC lattice. Its lattice parameter $a$ is related to radius through the arrangement of atoms. What is the close-packed direction in ...
- 4,071
1
vote
Energy balance for a system
You can eliminate Q and Ek as well. This is because the heat transfer between the water and ambient is negligible in hydro-electricity(for steam power plants Q might be significant) . Also, at the the ...
- 198
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