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Comment: Re:The Nobel Prize Committee blew it (Score 4, Informative) 276

by MattskEE (#48105143) Attached to: No Nobel For Nick Holonyak Jr, Father of the LED

The blue LED may have been harder than the red LED for the reasons that you give, but Holonyak did make some key accomplishments including the demonstration of a ternary alloy semiconductor and tuning the bandgap and thus color by varying alloy composition which has paved the way for achieving all of the different colors for LEDs in use today and is also used for the InGaN emission layer in the blue LEDs.

An alloy semiconductor instead of having, for example, one group III and one group V element in perfect 50% ratio in a uniform crystal structure mixes it up and uses two or more group III elements and two or more group V elements. In the case of Holonyak he used two group V elements: Arsenic and Phosphorous. At the time at least some people did not think that an alloy semiconductor would even work, and it is a little weird because the crystal structure is now non-uniform where a given group V crystal site contains one element or the other at random. In fact this randomness does slow down the electrons. Holonyak also showed that the bandgap could be tuned by varying the relative concentrations of the group V elements. You can read more about him in a nice IEEE profile.

I don't know enough about the history to say who should have gotten the Nobel, but certainly no matter who they selected somebody would have been snubbed.

Comment: Re:It's a boring choice (Score 1) 243

by MattskEE (#48086001) Attached to: 2014 Nobel Prize In Physics Awarded To the Inventors of the Blue LED

There isn't a limit of one prize per invention or discovery. The Physics and Chemistry Nobel prizes are frequently awarded decades after the original work was done.

The Nobel prize announcement did state that the significant impact of this invention was a factor in the selection. In addition to the huge commercial and societal impact of the work these researchers' work had a major scientific impact on the entire field of growth and properties of nitride semiconductors. LEDs are certainly the biggest application of nitride semiconductors but their work has also paved the way for nitride transistors in wireless and power electronics applications.

Comment: Re:12kW/day? (Score 2) 268

by MattskEE (#47989443) Attached to: IBM Solar Concentrator Can Produce12kW/day, Clean Water, and AC

Yes, it's a very crude estimate, and more of a summertime number too here in the US.

In the US I would refer them to PV Watts which will take examine a database of historical solar data and tell you how much daily energy to expect through the year for different types of setups, even including solar panel fixed angle or angle tracking systems. But it will not take into account your point on the effect of diffuse light on concentrated systems.

Comment: Re:12kW/day? (Score 5, Informative) 268

by MattskEE (#47989177) Attached to: IBM Solar Concentrator Can Produce12kW/day, Clean Water, and AC

It could also be 12kW peak, which with typical sunlight variation over a day would work out to around 60kWh per day.

Most of the time I see a non-technical article about solar with a kilowatt figure it's the peak power available from the cells, and as a first estimate you can multiply the peak solar power by 5 hours to get the daily output.

Comment: Re:Hmmm .... (Score 1) 200

by MattskEE (#47919821) Attached to: WSJ Reports Boeing To Beat SpaceX For Manned Taxi To ISS

Boeing doesn't do development work without a contract. So, when they got a contract to start development of their capsule, they started.

And then they stopped working on it as soon as the contract ran out. They're waiting on a new contract to resume work.

And this is a part of why aerospace/defense contractors are so expensive for the government to employ, and I say that having worked at some of them. Stringing together multiple contract awards to try to get to a larger goal, and continually going through the proposal writing process. A commercial company with a goal can strive continuously towards it in a more efficient manner, and the goal is success, not hours billed on a cost plus contract.

Comment: Re:Woohoo!! (Score 3, Informative) 106

The nanoparticles are magnetic, not magnets, which is an important different. It means that the nanoparticles will be attracted to an external magnetic field when it is applied, but they will not be attracted to each other.

Buckyballs were banned because if you swallow permanent magnets they can attract each other and could potentially pinch two parts of your intestine together, or other such unpleasant things which would be bad for you.

Swallowing permanent magnets: Bad idea.
Swallowing magnetic nanoparticles: Good idea assuming it passes the relevant medical trials for safety and effectiness.

Comment: Re:Everything old is new again (Score 1) 491

by MattskEE (#47874499) Attached to: To Really Cut Emissions, We Need Electric Buses, Not Just Electric Cars

It's my understanding that the electricity for the trolley buses is free.

If San Fran owns the power plant it means that they have paid for the cost of construction and ongoing operating and staffing costs, and by using the power internally rather than selling it they are paying the opportunity cost of not selling it and making money.

Free in this case just means a cost that appears in a different ledger.

Comment: Confusing summary - here's my version (Score 4, Informative) 74

by MattskEE (#47858433) Attached to: $10 Bet Brings Researchers Closer to Industrial Scale Graphene Production

The summary was not clear so here is my version based on my understanding of the work:

Graphite is composed of many randomly oriented and sized layers of graphene. Intercalation is a process where compounds or ions can be inserted between the layers of a layered material such as graphite. These Penn State reseachers have discovered a new way to perform this intercalation by leaving out a strong oxidizing agent which was thought to be necessary but would damage the graphene.

The research advisor Thomas E. Mallouk suggested trying it without the oxidizer. The researcher Nina Kovtyukhona was reluctant to perform this experiment as she thought it would be a failure. Her advisor persuaded her to try it by making a bet that he would pay her $100 if it succeeded, and she would pay him $10 if she failed. The experiment was a success, and researchers now have a new avenue to explore for synthesizing graphene.

My personal thought is that while this is scientifically interesting and could lead to some engineering benefits down the road this will not lead to large scale production of graphene since it is just splitting apart graphene sheets from graphite, and these sheets are generally quite small. Large scale production to me would be getting fairly good uniform growth or deposition of graphene over large areas of a substrate which is of the order of 1cm or larger so that it can eventually be scaled up to the 30cm and 45cm wafers in the silicon industry. So unless other researchers come up with a way to make a graphene boule composed of decent sized graphene sheets this technique does not seem useful for commercial electronics.

One things which makes graphene research expensive is that most growth methods end up with just little flecks of graphene material in random locations on a substrate, so a researcher or technician has to manually search for these and place contacts and gates on them using a manual lithography tool. It could even be automated but this would still be orders or magnitude slower than competing technologies.

A new route to making graphene has been discovered that could make the 21st century's wonder material easier to ramp up to industrial scale.

Whenever a press release uses language like this I am forced to point out that graphene so far has had zero compelling results for electronics applications. It is soundly beat by silicon and III-V semiconductors in terms of speed and dynamic range. Graphene transistors can be made reasonably fast (for certain but not all definitions of fast) but even so the signals that they can handle are only very tiny because of the lack of a bandgap. It has some wonderful properties but also some terrible ones which make its applicability suspect.

Comment: Re:Musk worship (Score 1) 260

by MattskEE (#47855373) Attached to: Tesla Plans To Power Its Gigafactory With Renewables Alone

Why are guys who run factories employing tons of US citizens in US based factories (like Toyota) who produce super reliable product with great mileage get slapped by the media when a bogus story about a gas pedal getting stuck?

Are you kidding? Just wait until Tesla slips up. They will eventually, and the media will jump all over them. The only thing that the media loves more than an underdog is the story of a fallen angel.

Media are jumping all over Tesla already.

It's happened with the Tesla car fires, which are still less common per mile driven than gasoline car fires. New York Times published a likely faked review where Tesla's data logging disagrees with the reporters account, and shows that the reporter only charged the battery to a small fraction of the capacity and ignored the low battery warnings while driving past charging stations. Top Gear also faked battery trouble on their show (it was apparently in the script before they even received the car from Tesla).

Comment: Re:TI calculators are not outdated, just overprice (Score 2) 359

by MattskEE (#47828501) Attached to: How the Outdated TI-84 Plus Still Holds a Monopoly On Classrooms

When I was an undergrad, most exams in advanced science and engineering classes allowed you to bring ANYTHING as long as it didn't involve communication with people outside the room. Forget about just calculators (ANY calculator), some people would be STACKS of textbooks, and I even remember some laptops (though those were less common back then -- largescale wireless also didn't quite exist yet).

When I first had a test like this, I packed a pile of books too, along with whatever calculator I had (I think a TI-85), etc. But I quickly realized that most of this was useless. In the limited time we had, if I didn't already know the stuff, I'm not going to have time to learn it from a book.

Same here, many engineering classes I had were open book, but a few profs had closed books and some didn't even allow calculators.

I had one excellent engineering prof who allowed one page of notes to exams, but no calculator. Most of the questions were asked in a way such that there was little to no numeric computation required, and when he did request a numeric answer it was simple stuff that he expected us to be able to simply and quickly do in our head or on paper. His philosophy was that you need to understand the problem well enough and break it down to analyzable pieces sometimes with approximations so that you can get within ~5% of the correct numeric answer by hand analysis, and if higher accuracy is required it will generally be optimized on the computer with software you bought or wrote.

The homework problems would cover more rigorous computations and computer simulations, the tests were designed to see if you truly understood the problems at hand.

Natural laws have no pity.

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