Gap Definition and 267 Threads

As far as I can tell, none of these come with the student edition of PSpice. The first problem is I can't find a model for any of these things. The second problem is I don't know how to import a custom part. Worst come to worst, I could make the part myself, but once again, I have no experience...

Hello. I'm a cabinetmaker and my college physics courses are 25 years behind me now. I'd consider it a kindness if someone would answer a question for me regarding magnetism. I have a magnetic strip that is described as having 6.2 lb. of magnetic pull force per lineal foot, 1" wide and 0.020"...

I have to plan the layout of a sprinkler system. Basically, each sprinkler shoots a radius of 7.5 feet water, and I want every part of the floor covered with water. How can I use the least number of sprinklers?

I'm reading a paper on photovoltaic hydrogen production and the author claims that for reasonable solar efficiencies the band gap must be less than 2.0eV. This I understand. My question is how will it effect the photon absorption if the band gap is much smaller. Say the band gap energy is...

In the limit of weak coupling, G\overline{ρ}<<1, the BCS pairing gap equation gives that Δ \propto exp(-1/G\overline{ρ}). \overline{ρ} is the level density.This cannot be developed as a power series in the interaction strength G. Does this imply that there is a phase transition between a...

Energy gap dependence on temperature for intristic semiconductors (Si,Ge) I need help on this topic, where to find text about this, and models that describe it (Varshni's model, linear model,...)

Hi everyone , this is my first post here :) . I am an auto electrician , my hobby is photography. I am interested in high speed photography and have invented a new form of photography in a way . I call it 'superspeed photography' . It involves taking a picture of something that is triggered by...

I'm going to go ahead and put this to the board, figure I might as well. I'm 30 years old, and a pretty quiet person. Friendly, polite, but stand-offish with most people. Anyway, enough with the background. There's a girl at my work who I think is great. She's gorgeous, a little reserved, and...

If we assume that the Twin Prime Conjecture is true (and thus there are infinite number of primes that are 2 apart), how reasonable is it to assume that there will be an infinite number of Twin Primes that are preceded by a prime that is at least 10 lower than the first of the Twin Primes? (I...

Hello, do you know why no electron can stay in the band gap? Is it impossible at every energy? Thank you!

Dear Experts Does anyone know how big can we extend the gap between the 2 plates? Thanks. Regards Ramone

Might be an easy question (or not). What determines the band gap of an element? As far as I know, silicon is the most efficient single-element semiconductor because of it's small (but nonzero) bandgap. Next (as far as I know) is Selenium. I'm aware there are more efficient compounds, but...

Are there any known gap junction openers/closers for C. elegans? I've googled far and wide for weeks. Trimethylamine, quinine, and carbenoxolone are known to work with connexins in mammals. They also happen to be expensive and require more paperwork, so I don't want to go through the steps...

Homework Statement A toroidal shaped magnetic material of radius, a, and cross sectional radius R has a small transverse gap cut into it of length l. The toroid is uniformly overwound with a coil of N loops carrying a current I. Show that for a ferromagnetic material the field in the gap is...

I am reading about solid state electronics(semiconductors). I've read that when atoms of many many atoms are brought close each other,as in a solid, the energy levels of energy states of different atoms get split up into different closely lying energy states collectively forming a band...

Homework Statement Calculate Efi with respect to the center of the bandgap in silicon for t= 200, 400, 600 kelvin. Homework Equations ni = Nc e^-((Ec- Ef)/(kt)) k = boltzman constant t= temperature in kelvin Ec = energy level of the conduction band ef= fermi energy level ni=...

Homework Statement A capacitor is completely charged with 670 nC by a voltage source that had 200 V. What is its capacitance?==== 3.35×10-9 F 9(I got this y doing Q/V) The initial air gap of the capacitor above was 7 mm. What is the stored energy if the air gap is now 10 mm? Now...

Homework Statement Most solar radiation has a wavelength of 1 µm or less. (a) What energy gap should the material in a solar cell have if it is to absorb this radiation? (b) Is silicon an appropriate solar cell material? Explain your answer. Homework Equations f = c/lambda E =...

Perhaps this explains the mass gap between neutron stars and stellar mass black holes. http://arxiv.org/abs/1110.1635 Missing Black Holes Unveil The Supernova Explosion Mechanism

Does a spark gap increase the current in a circuit? My thinking is that the surrounding air is ionized and any "stripped" free electrons would add to the current.

Does anyone here know of a possible bridge degree between a bachelor's deg in electronics engineering and a degree in planetary science? I plan to pursue degrees in astronomy and then planetary science without wasting my five years with electronics. Is it possible to link them? If so, what...

hello i have a question given to me on a tutorial which is to find what is the largest IRG that will allow 80 percent of the tape to be data in 2400 foot magnetic tape has recording density 6400 Bpi and data records are 100 bytes and memory buffer is 10,000. i have been looking every where but i...

Take the test http://www.pbs.org/newshour/rundown/2011/08/wealth-how-does-the-us-slice-the-pie.html Video and text http://www.pbs.org/newshour/bb/business/july-dec11/makingsense_08-16.html Hopefully my point is obvious. When faced with the facts in terms easy to understand, most...

Homework Statement A cyclotron is a particle accelerator made of two electrodes shaped as two empty half-circles separated by a small gap. We consider the dees as lying on the x-y plane, having radius R, both with centre in the origin, and each occupying the semiplane of positive and...

We all know that there exist pseudogap in superconductors and in metals (semimetals). Were there the experiments, aimed to find gaps analogues to pseudogap in phonon spectrum? Is pseudogap T* is connected with some change in phonon spectrum in some direction? The same question for...

Hiya, been given this question which I am having problems with. Semi conductor quantum well structure contains a 100A thick layer of GaAs between thick AlGaAs layers. Find the band gap for the structure, where GaAs has the following parameters; conduction band effective mass 0.067 me, heavy...

3.5" FDD head size: size of the gap of the read/write heads I doubt anyone here knows the answer, but I thought I would ask anyway. I mean, I know not of a better forum on which to ask... Anyway, does anyone happen to know the size of the gap of the read/write heads of a 3.5" floppy disk...

The band gap discontinuity in DFT? Hi everybody... I've read about the band gap problem of Density functional theory, there is a discontinuity of the band gap when an electron add to the Kohn-Sham system I have two questions could anybody answer me? please 1- why this discontinuity happens...

I am not able to understand how a bandgap voltage reference works. The simplest ckt I found was here - (figure 2) - http://www.national.com/rap/Application/0,1570,24,00.html You have 2 branches of diodes, in one branch rich (high) current flows and in the other lean (small) current flows...

Homework Statement Hi, I have some values of conductivity in some temperatures. 0.01 at 400 Kelvin 10 at 600 K 70 at 700 K 1000 at 1000 K And I'm asked to find the energy gap of this intrinsic semi- conductor. Homework Equations The Attempt at a...

When we say generally TiO2 band gap energy, is it meaning direct or indirect band energy? Some papers show only direct BG or indirect BG or both. Is it right that one semiconductor has one of direct and indirect BG. I am a little bit confused.

ok let's say i have a semiconductor like germanium with band gap of around 0.67eV at rtp. so this means that i need around 0.67 x 10-19 J of energy to cause valence electrons to jump to conduction band right? do i use the formula E = 1/2 kT to relate this energy to temperature? so i...

http://www.miller-mccune.com/science/the-real-science-gap-16191/ Nothing Earth shattering to people in this group, but a nice summary of the problem.

Hi all I was wondering if I could solve the schrodinger's equation to see the limiting velocity for a proton to tunnel through the coulomb gap in order for the first equation in the fusion reaction to occur Thanks a lot

Dear all, Recently, some young people and I started a project that may be called "Piecewise-linear ball complexes: calculations with GAP". As to me, my direct aim is to make calculations in some TQFT's (topological quantum field theories) naturally defined on PL ball complexes of any...

I am struggling a bit with this problem: I have a pipe with a constant surface temperature of 1100F. I also have a tank which cannot reach a temperature higher than 258F. I am trying to figure out the minimum distance between the two (in 80F air, which will be moving at a minimum of 5 ft/sec)...

One of our college's physics seniors scored poorly on the physics subject GRE and is looking for something to do for a year while s/he studies for, and retakes this test. Our student would like to find an appropriate position at a lab (academic, industrial, government...) which provides enough...

sorry i moved it to correct forum i rushed in, in my panic

Is anybody familiar with this program? Better yet, can someone explain to me how to find subgroups of index 2 (or index a power of 2)? Thanks.

Hello, I am currently working on a PCB design project, just wondering if anybody knows how to reduce the size of the gap(the black circular region) around individual pin of IC Chips (after I have done the polygon pour) so that a 0.5mm ground track can get through. In addition, what is the...

indirect band gap semiconductor doubt its said that indirect band gap semiconductors like silicon and germanium are not used as a light sources because they have more non-radiative recombinations rather than radiative ,which inturn decreases efficiency of optical source. but i want to...

I am a senior Physics/Math major. I want to go to grad school (99% sure) but I am not ready to start immediately after undergrad, I hope to bike to and live in South America next year. My question is, how harmful will this be to my chances at getting into a top tier physics Pd.D. program the...

Is it possible for electricity to jump a vacuum gap? If so, what is it called when that happens?

Here and there some rumors come out about this relevant problem. I have read the following article in Wikipedia http://en.wikipedia.org/wiki/Yang–Mills_existence_and_mass_gap and the talk page http://en.wikipedia.org/wiki/Talk:Yang–Mills_existence_and_mass_gap but people cited there...

I. Introduction With great sadness I note the passing of one of the Best Things Ever: a few days ago, John Baez posted the final installment (Week 300) in his long-running internet column, This Week's Finds in Mathematical Physics. But John himself is not sad; he is desperate--- to...

Hi all, I've calculated the exciton binding energies for different semiconductors using the Bohr model. It works remarkably well for direct gap semiconductors, but it is not good for indirect gap semiconductors (in Si and Ge, there is an underestimation by a factor of 3, approximatively)...

Hello, I just finished school and I want to study physics, but I have to wait about 1.5 years until I can start with it. What would you recommend to stay in touch with physics during that time? Reading books would be the thing I came up with, would you say that reading in forums like this...

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)...

I was wondering that how the knowledge o transmittance and reflectance curves can give us information about the band gap and electronic structure of a metal? How these curve differ for semiconductors? I desperately tried to extract n, k values from the reflectance curve of a nitride material...

Hey I was studying for my test, in my notes it says si cannot be used for led, because it has indirect band gap.Why indrect band gap is not useful for led?