text:
Materials Science and Engineering/Doctoral review questions/Daily Discussion Topics/01202008

nMOS
nMOS logic uses n-type metal-oxide-semiconductor field effect transistors (MOSFETs) to implement logic gates and other digital circuits. nMOS transistors have three modes of operation: cut-off, triode, and saturation (sometimes called active).

The n-type MOSFETs are arranged in a so-called "pull-down network" (PDN) between the logic gate output and negative supply voltage, while a resistor is placed between the logic gate output and the positive supply voltage. The circuit is designed such that if the desired output is low, then the PDN will be active, creating a current path between the negative supply and the output.

As an example, here is a NOR gate in nMOS logic. If either input A or input B is high (logic 1, = True), the respective MOS transistor acts as a very low resistance between the output and the negative supply, forcing the output to be low (logic 0, = False). When both A and B are high, both transistors are conductive, creating an even lower resistance path to ground. The only case where the output is high is when both transistors are off, which occurs only when both A and B are low, thus satisfying the truth table of a NOR gate:

While nMOS logic is easy to design and manufacture (a MOSFET can be made to operate as a resistor, so the whole circuit can be made with nMOSFETs), it has several shortcomings as well. The worst problem is that a DC current flows through an nMOS logic gate when the PDN is active, that is whenever the output is low. This leads to static power dissipation even when the circuit sits idle.

Also, nMOS circuits are slow to transition from low to high. When transitioning from high to low, the transistors provide low resistance, and the capacitative charge at the output drains away very quickly. But the resistance between the output and the positive supply rail is much greater, so the low to high transition takes longer. Using a resistor of lower value will speed up the process but also increases static power dissipation.

Additionally, the asymmetric input logic levels make nMOS circuits susceptible to noise.

These disadvantages are why nMOS logic was supplanted by CMOS logic both in low-power and in high-speed digital circuits, such as microprocessors, during the 1980s.

CMOS

Complementary metal–oxide–semiconductor (CMOS) (pronounced "see-moss", IPA: /siːmɔːs, ˈsiːmɒs/), is a major class of integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. CMOS technology is also used for a wide variety of analog circuits such as image sensors, data converters, and highly integrated transceivers for many types of communication.

CMOS is also sometimes referred to as complementary-symmetry metal–oxide–semiconductor. The words "complementary-symmetry" refer to the fact that the typical digital design style with CMOS uses complementary and symmetrical pairs of p-type and n-type metal oxide semiconductor field effect transistors (MOSFETs) for logic functions.

Two important characteristics of CMOS devices are high noise immunity and low static power consumption. Significant power is only drawn when the transistors in the CMOS device are switching between on and off states. Consequently, CMOS devices do not produce as much waste heat as other forms of logic, for example transistor-transistor logic (TTL). CMOS also allows a high density of logic functions on a chip.

The phrase "metal–oxide–semiconductor" is a reference to the physical structure of certain field-effect transistors, having a metal gate electrode placed on top of an oxide insulator, which in turn is on top of a semiconductor material. Instead of metal, current gate electrodes (including those up to the 65 nanometer technology node) are almost always made from a different material, polysilicon, but the terms MOS and CMOS nevertheless continue to be used for the modern descendants of the original process. Metal gates have made a comeback with the advent of high-k dielectric materials in the CMOS process, as announced by IBM and Intel for the 45 nanometer node and beyond.


text: File:Zon Piano Velocitys.ogg

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: File:Zon Piano Velocitys.ogg


text:
Automotive Technology/Tire

Resources

 * Tire
 * Wheel
 * Car
 * Pneumatics
 * Wheel sizing
 * Tire code
 * Tire manufacturing
 * Retread
 * UTQG

title: Automotive Technology/Tire


text:
User:Christve

I am BrittleMermaid. I am quite excited baout being a part of my most favorite search/information engine 'Wickipedia'.

I am keen in learning and I beleive Wickipedia offers all the information, without contradiction.

I am here looking for active knowledge/opinion sharing in topics like religion, World's politics, AML and books.

Hoping to meet the gems of your kind,

title: User:Christve


text:
User talk:Un-predictable

Welcome
Hello Un-predictable, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
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And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Countrymike 08:41, 21 January 2008 (UTC)

Un-predicatble: there's generally quite lively discussion going on on IRC, see: Chat or also the Help_desk is the place to ask questions about any subject (kind of like the WP reference desk) but often there is little discussion. Colloquium is the place for talk about Wikiversity. Countrymike 06:17, 22 January 2008 (UTC)

Hi Un-predictable. Thank you for your nice words. You made me feel very well. So conics, integration and permutation. Sure I can help! Just ask whatever you want and I'll try my best to help (and as a benefit we get a wikiversity lesson as a result :) ) --Jorge 21:11, 9 April 2008 (UTC)

title: User talk:Un-predictable


text:
User talk:Christve

Welcome
Hello Christve, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
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And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Countrymike 08:42, 21 January 2008 (UTC)

title: User talk:Christve


text:
User:MJBurrage

on Wikipedia

Released into public domain
I agree to release my text and image contributions, unless otherwise stated, into the public domain. Please be aware that other contributors might not do the same, so if you want to use my contributions under public domain terms, please check the multi-licensing guide.

title: User:MJBurrage


text:
User:KirbyPuckettFan

=Main Details=

Name: Chris J. Age: 28 Location: Sioux Falls, South Dakota, USA E-mail: [mailto:chrisj80@gmail.com chrisj80@gmail.com]

=On Wikiversity=

French Department English Department
 * La Littérature du 18e siècle: A class I teach

=Outside Wikiversity=

La Littérature des Lumières: My e-mail discussion list for 18th Century French Literature (in French)

Tout de Chris: My French-language blog

Subterrestrials: An SF novella I'm writing

I'm also on MySpace and Facebook.

title: User:KirbyPuckettFan


text:
User talk:MJBurrage

Welcome
Hello MJBurrage, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
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And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Countrymike 09:52, 21 January 2008 (UTC)

title: User talk:MJBurrage


text:
User talk:KirbyPuckettFan

Welcome
Hello KirbyPuckettFan, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
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 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Countrymike 10:15, 21 January 2008 (UTC)

Bienvenue, etc.
If you need any help, just ask. I speak French, but am being REALLY lazy right now. The Jade Knight 05:21, 14 March 2008 (UTC)

Remember to toss your time zone up on the Mentoring page; I figure it would be ideal to match people according to time zone in addition to proficiency. The Jade Knight (d'viser) 04:08, 15 October 2008 (UTC)
 * Already taken care of. Thanks for getting involved.  The Jade Knight (d'viser) 20:30, 21 October 2008 (UTC)
 * No problem. Just let me know if I can do anything else for you.  The Jade Knight (d'viser) 21:40, 21 October 2008 (UTC)

fiction
I need to work on separating myself from what I write <-- one was to do this is to participate in collaborative writing. What kinds of fiction and topics do you enjoy? --JWSchmidt 14:50, 22 October 2008 (UTC)

 * "posts are a bit messy" <-- we live in a messy world. For some things, chat is better (quicker) than posting on wiki. I wonder if you ever use IRC chat...normally I hang out in #wikiversity-en but an abusive channel op recently banned me from that channel (no discussion, no warning, no reason for the ban) so you can find me in #fiction-wikia, a chat channel just for collaborative fiction writing. Science fiction is my main area of interest in fiction writing, not sure if you saw Science Fiction Challenge...I'm looking for collaborators at Mnemtronium and The nanoepitaxy of Susanne Marie. "struggle with pinning down specific details" <-- a nice feature of collaborative fiction writing is that some people can focus on "the big picture" while other more detail-oriented people can worry about the details. "pure fantasy worlds" <-- I've never been able to get interested in writing fantasy. I seem to need to retain a few more connections to reality than do people who thrive on fantasy. "Asimov, but I could never be as technical as him" <-- he wrote an amazing range of fiction, some of which was less technical and specifically created with young people in mind. One of my projects is actually a kind of "Asimov fan fiction" in which I am making a sequel to one of Asimov's novels (see). "focusing on the 'hero' or 'heroine'" <-- Another Wikiversity participant who collaborates with me on fiction writing (User:Davichito) and I were recently talking about this in the #fiction-wikia chat channel. I have a real problem writing about traditional hero-type characters...or tradition "bad guys", for that matter. It might be fun if we could collaborate on a story that shows an interesting character "working through the psychological effects his or her tumultuous past"....Davichito is particularly interested in psychological issues. We are working on a story about a character called "Kalid" who has an amazing past that could be expanded on. --JWSchmidt 00:29, 23 October 2008 (UTC)

 * >Another Wikiversity participant who collaborates with me on fiction writing (User:Davichito). Yep. That's me. I read your post to JWSchmidt and I also like Asimov a lot. I think you could collaborate with us. The good writer is JWSchmidt, I am just a beginner on this and I have learned much things about fiction writing thanks to him. So, if you want to join us, you could practice too teach us things too. All of us are learning, I guess. Your knowledge about Star Wars could help to Kalid story; it is similar in some fashion: there are mental powers (not exactly the kind of mind control that Jedis use, there is telepathy), there is a Galactic Empire, there is a wise character similar to Yoda (Kalid is human but he is a Grand Master of the Osiris Order and he is very special in some things). I recommend http://ficcion.wikia.com if you want to upload your science fiction stories to the world, in case you have not done it yet.

 * I also saw you have an interest in French. Est-ce que vous êtes francophone? Je parle français comme seconde langue. Je vous attends à Ficcion Wikia, je veux savoir ce qui vous pensez sur Kalid. Davichito 01:06, 25 October 2008 (UTC)

We miss you at IRC. Davichito 16:01, 3 November 2008 (UTC)

Subterrestrials
"mutation of the original alien species" <-- Genetic engineering is one of my favorite themes for fiction. Two interesting examples of this kind of fiction are the aliens in "Assignment Nor'Dyren" and M. A. Foster's "Ler". The "Ler" are genetically modified humans. One type of genetic engineering that is fairly common in science fiction is efforts to change other species such as chimps into more human-like variants (for example, David Brin's "Uplift" fictional universe). Recently, Davichito and I have been talking about Animism and Animal worship and "Subterrestrials" got me thinking about the idea that humans might try to make genetic variants of the human species that are similar to other species such as large felines. --JWSchmidt 13:54, 25 November 2008 (UTC)

 * "my idea is not so much about mutating humans" "Saurok-earth cat hybrids" <-- If it is possible for Sauroks to mate with Earth cats then I doubt if Sauroks could originate on another planet by a natural evolutionary process. However, as discussed here, it might be possible to make the story include the idea that the Luminads and Sauroks are actually of terrestrial origin. I started by imagining that Luminads might actually be humans, but another alternative would be that millions of years ago a cat species was taken off of Earth and genetically engineered to become human-like (in the sense of having human-like intelligence and the ability to use advanced technologies). If you do not like that kind of approach, then I think it would be very hard to have anything like a "mutation" spreading from alien Sauroks to "Saurok-earth cat hybrids" and then on to humans. An alternative would be to have some kind of infectious agent that could spread from an alien life form to life forms from Earth, but it is difficult to imagine how such an infectious agent could have a specific behavioral effect like making the infected animals "more predatory". What I am struggling with is finding a way to stay within the confines of "hard science fiction". If you are satisfied to have "Hollywood-style science fiction" where "mutation" does not have to actually follow any biological rules, then you can do anything you want to do! --JWSurf 04:24, 26 November 2008 (UTC)

Mentoring
We now have four native French speakers signed up to tutor at the French Mentoring program. Xionbox is available at about 3pm CST, and speaks English co-natively. The others speak intermediate English and are probably available earlier in the day (but who knows...) Do you have preferences for a Mentor? The Jade Knight (d'viser) 17:00, 4 November 2008 (UTC)
 * I use Pidgin to handle all of my IM and IRC. It's more limited than most IM programs, though, so you may not prefer it (it cannot currently handle voice or video chat, for example).  The Jade Knight (d'viser) 09:16, 5 November 2008 (UTC)
 * Have you established contact with Xionbox? How goes the search for a Mentor?  The Jade Knight (d'viser) 10:59, 8 November 2008 (UTC)
 * Try the "email this user" function. The Jade Knight (d'viser) 12:18, 9 November 2008 (UTC)

IRC
To enter #fiction-wikia you can go to http://irc.wikia.com and connect from there, they have a dropdown list of channels. Or you can go to http://java.freenode.net and fill the nickname and channel fields. Or you can do as I do: use chatzilla from firefox browser.

For the wiki interface, you click More (at the top right) then Manage Widgets. You click the right arrow until you find Shout box. Then you click in the green + button and you are ready to use it. It is placed at the left of the screen.

Davichito 02:50, 5 November 2008 (UTC)

Mentoring
Would you be willing to Mentor Soroush? He/she is a beginning learner of French located in UTC+3, whose native language appears to be Farsi, but evidently speaks English at an "intermediate" level. The Jade Knight (d'viser) 04:56, 24 November 2008 (UTC)

 * Would you be willing to take on additional students? If so, how many?  The Jade Knight (d'viser) 06:39, 28 August 2009 (UTC)

 * It is natural, I think, that some fall by the wayside as they get busy, etc. I have not heard anything from Soroush, so I assume he/she is still yours, unless you would like to relinquish mentorship of him/her.  In the meantime, would you be willing to take on any others?  The Jade Knight (d'viser) 05:58, 30 August 2009 (UTC)
 * Could you please Mentor Jpaagt, then? He/she is in Bogotá, Columbia, putting them in UTC -5, same as you.  He/she appears to speak English well, though it's probably not their native language.  He/she is a beginning French student.  The Jade Knight (d'viser) 20:42, 30 August 2009 (UTC)

Salut
Salut
 * Je suis heureux de voir que vous pouvez me apprendre Francaise. Est que je vous connais plus et je veux savoir que quand et ou je peux vous voir?
 * Merci. à bientôt.--Soroush 21:06, 25 November 2008 (UTC)

bon jour!
salut, j'etais indisponible pedant quelques semaines, dsl de repondre que maintenant... ravi de fair ta connaissance et j'aimerais bien t'aider a ensegner ta classe. keep in touch!

 * I'm more familiar with Voltaire, Robespierre, and Mirabeau, but I would also include Moliere, he's pretty important in 18th century French literature...more like the French equivalent of William Shakespeare, but it's reallly neat from what i've seen so far, and hopefully next time I'll have a little more time to get a better glance.

 * Look forward to workin with you as well, but hopefully after winter break, I'll have lots more free time. You can email me at francolucien @ ymail .com
 * --Jfrankc08 16:57, 26 December 2008 (UTC)
 * salut!

title: User talk:KirbyPuckettFan


text:
User:Sangeeta BG

Starting a learning community KOIIA from 31 Jan 2008. The following (in alphabetical order) make up this community:

 * Karin Allard
 * Sangeeta Bagga-Gupta
 * Sara Fröden
 * Marie Nordmark
 * Jenny Rosen Gomez
 * Oliver St-John

Our community will allow its members to navigate a research course that will be delivered during the 1st term of 2008 both in face-to-face meetings and through wikiversity. Let us see where we get by May 2008.

Our ongoing course has seminars on the following dates and a learning resource on intersectionality and education should be up here by mid-August 2008:

 * 31 January 2008
 * 14 February 2008
 * 27 February 2008
 * 6 March 2008
 * 24 April 2008
 * 3 June 2008
 * 28 August 2008

It is our aim that the learning resource that we create will be a resource for members of the wiki-community.

title: User:Sangeeta BG


text: Category:Wikimedian Demographics/Wikipedia/Arbcom/Response categories


text: Category:Wikimedian Demographics/Wikipedia/Response categories


text:
User:Jacksojt

Jackson
Indiana University, Instructional Strategies and Tactics

The image is a compilation and adaptation of the Strategic Impact Model by Molenda and the Designing Effective Instruction Model from Morrision, Kemp, and Ross. The key emphasis is on evaluation as the cornerstone.

title: User:Jacksojt


text:
User talk:Jacksojt

Welcome
Hello Jacksojt, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
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 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --mikeu 15:47, 21 January 2008 (UTC)

image info
May I ask why you removed the info from the Image:Performancemodel.gif image that you uploaded? It is very helpfull to have a description, but more importantly there needs to be a license selected. Feel free to contact me if you need any help in choosing a license or if you have any questions. --mikeu talk 05:49, 22 January 2008 (UTC)
 * Please provide a license template and source for this image. Thanks. – Mike.lifeguard | @en.wb 22:09, 13 February 2008 (UTC)

title: User talk:Jacksojt


text: User:Cbrown1023/Survey responses

title: User:Cbrown1023/Survey responses


text: Category:WMDGS/Rarely contributes to Wikispecies


text: Category:WMDGS/Primarily contributes to Meta


text: Category:WMDGS/Has visited Mexico

title: Category:WMDGS/Has visited Mexico


text: Category:WMDGS/Wikipedia/notability about right


text: Category:WMDGS/Wikipedia/number of policies about right


text:
Wikimedian Demographics/Canada

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text:
Wikimedian Demographics/Mexico

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title: Wikimedian Demographics/Mexico


text:
Wikimedian Demographics/United Kingdom

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text:
Wikimedian Demographics/France

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text:
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title: Wikimedian Demographics/Italy


text:
Wikimedian Demographics/Ireland

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title: Wikimedian Demographics/Ireland


text: User:DGGV/Survey responses

title: User:DGGV/Survey responses


text:
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text:
User:Benjism89

meta:User:Benjism89

title: User:Benjism89


text: User:Benjism89/Survey responses

title: User:Benjism89/Survey responses


text:
User:Fruggo

Hello! Usually you can find me at nl.Wikipedia.

title: User:Fruggo


text:
User:Russian F~enwikiversity

See my wikipedia userpage.

title: User:Russian F~enwikiversity


text:
Electricity/Principles

Basic formulas calculating resistance, current, voltage, and power- where:
 * V= voltage (Measured in Volts)
 * I= current (Measured in Amperes)
 * R= resistance (Measured in Ohms)
 * P= power (Measured in Watts)

Symbols and Abbreviations
The symbols used for quantities in electrical engineering can be confusing, since the symbol for a quantity may be different from the symbol for the units in which it is measured. We list the common symbols here, even though we have not yet defined all of the concepts involved.

Electrical charge

 * is typically denoted $$Q$$, measured in coulombs, abbreviated $$C$$.

Current

 * is typically denoted $$I$$, measured in amperes, abbreviated $$A$$.

An ampere is, among other things, a coulomb per second.

 * Example: $$V = IR\,$$  Ohm's law; voltage equals current times resistance.
 * Example: "$$I = 28mA\,$$"  "The current is 28 milliamperes."

Voltage

 * is typically denoted $$V$$ (or sometimes $$E$$), and measured in volts, abbreviated $$V$$. The use of "$$E$$" stands for "emf" (electro-motive force.)

A volt is, among other things, a joule per coulomb.

 * Example: "$$V = 28mV\,$$"  "The voltage is 28 millivolts."

Resistance

 * is typically denoted $$R$$, measured in ohms, abbreviated with the capital Greek omega: $$\Omega$$.

An ohm is, among other things, a volt per ampere.

 * Example: "$$R = 2.7K\Omega\,$$"  "The resistance is 2.7 kilohms."

Conductance

 * It is sometimes useful to speak of the reciprocal of resistance. This is called conductance, and is typically denoted $$G$$, traditionally measured in "mhos" ("mho" is "ohm" spelled backwards), abbreviated with an upside-down omega: $$\mho$$.  A less flippant term than "mho" has been adopted: the siemens, abbreviated $$S$$.

A mho/siemens is, among other things, an ampere per volt.

 * Example: $$I = VG\,$$  Ohm's law rewritten in terms of conductance.
 * Example: "$$G = 65m\mho\,$$"  "The conductance is 65 millimhos."
 * Example: "$$G = 65mS\,$$"  "The conductance is 65 millisiemens."

Capacitance

 * is typically denoted $$C$$, measured in farads, abbreviated $$f$$.

A farad is, among other things, a second per ohm, or a coulomb per volt.

 * Example: $$t = RC\,$$  The time constant is the resistance times the capacitance.
 * Example: "$$C = 75pf\,$$"  "The capacitance is 75 picofarads."

Inductance

 * is typically denoted $$L$$, measured in henries, abbreviated $$h$$.

A henry is, among other things, an ohm-second.

 * Example: $$f = \frac{1}{2\ \pi\ \sqrt{L\ C}}$$  is the formula for the frequency of a resonant circuit.
 * Example: "$$L = 120nh\,$$"  "The inductance is 120 nanohenries."

Power

 * is typically denoted $$P$$, measured in watts, abbreviated $$W$$.

A watt is, among other things, a joule per second, or a volt-ampere.

 * Example: $$P = VI\,$$  The power is the voltage times the current.
 * Example: "$$P = 75W\,$$"  "The power is 75 watts."

The frequency

 * of an oscillation or signal is typically denoted $$f$$, measured in hertz, abbreviated $$Hz$$.

A hertz is really just a reciprocal second. In fact, the unit of frequency used to be just "cycles per second" or simply "cycles".

 * Example: "$$f = 102.5 Mc\,$$"  "102.5 megacycles on the FM dial" (old way.)
 * Example: "$$f = 102.5 MHz\,$$"  "102.5 megahertz on the FM dial" (new way.)

It happens that, in a lot of the mathematical formulas the unit of radians per second is superior. A frequency in radians per second is $$2\ \pi$$ times the frequency in hertz. When measured this way, the symbol $$f$$ is replaced with the lower-case Greek omega: $$\omega$$. Many occurrences of $$2\ \pi$$ disappear from various formulas when radians are used.

 * Example: $$\omega = \frac{1}{\sqrt{L\ C}}$$  is the formula for the frequency of a resonant circuit, in radians per second.
 * Example: $$X_C = \frac{1}{2\ \pi\ f\ C}$$  is the formula for capacitive reactance, calibrated in hertz.
 * Example: $$X_C = \frac{1}{\omega\ C}$$  is the formula for capacitive reactance, calibrated in radians per second.
 * Example: "$$\omega = 644.0265mrad/s\,$$"  "644.0265 megaradians per second on the FM dial" (not known to have ever been announced.)

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Materials Science and Engineering/Doctoral review questions/Daily Discussion Topics/01122008

Variational Principle
Say you have a system for which you know what the energy depends on, or in other words, you know the Hamiltonian H. If one cannot solve the Schrödinger equation to figure out the ground state wavefunction, you may try any normalized wavefunction whatsoever, say φ, and the expectation value of the Hamiltonian for your trial wavefunction must be greater than or equal to the actual ground state energy. Or in other words:

 * $$E_{ground} \le \left\langle\phi|H|\phi\right\rangle $$

This holds for any trial φ, and is obvious from the definition of the ground state wavefunction of a system. By definition, the ground state has the lowest energy, and therefore any trial wavefunction will have an energy greater than or equal to the ground state energy.

Proof
Your guessed wavefunction, φ, can be expanded as a linear combination of the actual eigenfunctions of the Hamiltonian (which we assume to be normalized and orthogonal):
 * $$\phi = \sum_{n} c_{n}\psi_{n} \,$$

Then, to find the expectation value of the hamiltonian:

 * $$\left\langle\phi|H|\phi\right\rangle \, $$
 * $$ = \left\langle\sum_{n}c_{n}\psi_{n}|H|\sum_{m}c_{m}\psi_{m}\right\rangle \,$$
 * $$ = \sum_{n}\sum_{m}\left\langle c_{n}\psi_{n}|E_{m}|c_{m}\psi_{m}\right\rangle \,$$
 * $$ = \sum_{n}\sum_{m}c_{n}^*c_{m}E_{m}\left\langle\psi_{n}|\psi_{m}\right\rangle \,$$
 * $$ = \sum_{n} |c_{n}|^2 E_{n} \,$$
 * }
 * $$ = \sum_{n}\sum_{m}c_{n}^*c_{m}E_{m}\left\langle\psi_{n}|\psi_{m}\right\rangle \,$$
 * $$ = \sum_{n} |c_{n}|^2 E_{n} \,$$
 * }
 * $$ = \sum_{n} |c_{n}|^2 E_{n} \,$$
 * }
 * }

Now, the ground state energy is the lowest energy possible, i.e. $$E_{n} \ge E_{g}$$. Therefore, if the guessed wave function φ is normalized:
 * $$\left\langle\phi|H|\phi\right\rangle \ge E_{g}\sum_{n} |c_{n}|^2 = E_{g} \,$$

Hartree
The origin of the Hartree-Fock method dates back to the end of the 1920s, soon after the derivation of the Schrödinger equation in 1926. In 1927 D.R. Hartree introduced a procedure, which he called the self consistent field method, to calculate approximate wavefunctions and energies for atoms and ions. Hartree was guided by some earlier, semi-empirical methods of the early 1920s (by E. Fues, R.B. Lindsay and himself) set in the old quantum theory of Bohr. In the Bohr model of the atom, the energy of a state with principal quantum number n is given in atomic units as E = − 1 / n2. It was observed from atomic spectra that the energy levels of many-electron atoms were well-described by applying a modified version of Bohr's formula. By introducing the quantum defect d as an empirical parameter, the energy levels of a generic atom was well approximated by the formula E = − 1 / (n + d)2, in the sense that one could reproduce fairly well the observed transitions levels observed in the X-ray region. The existence of a non-zero quantum defect was attributed to electron-electron repulsion which clearly does not exist in the isolated hydrogen atom. This repulsion resulted in partial screening of the bare nuclear charge. These early researchers later introduced other potentials containing additional empirical parameters with the hope of better reproducing the experimental data.

Hartree sought to do away with empirical parameters and solve the many-body time-independent Schrödinger equation from fundamental physical principles, i.e. ab initio. His first proposed method of solution became known as the Hartree method. However, many of Hartree's contemporaries did not understand the physical reasoning behind the Hartree method: it appeared to many people to contain empirical elements, and its connection to the solution of the many-body Schrödinger equation was unclear. However, in 1928 J.C. Slater and J.A. Gaunt independently showed that Hartree's method could be couched on a sounder theoretical basis by applying the variational principle to an ansatz (trial wavefunction) as a product of single-particle functions.

In 1930 Slater and V.A. Fock independently pointed out that the Hartree method did not respect the principle of antisymmetry of the wavefunction. Hartree's method used the Pauli exclusion principle in its older formulation, forbidding the presence of two electrons in the same quantum state. However, this was shown to be fundamentally incomplete in its neglect of quantum statistics.

It was then shown that a Slater determinant, a determinant of one-particle orbitals first used by Heisenberg and Dirac in 1926, trivially satisfies the antisymmetric property of the exact solution and hence is a suitable ansatz for applying the variational principle. The original Hartree method can then be viewed as an approximation to the Hartree-Fock method by neglecting exchange. Fock's original method relied heavily on group theory and was too abstract for contemporary physicists to understand and implement. In 1935 Hartree reformulated the method more suitably for the purposes of calculation.

The Hartree-Fock method, despite its physically more accurate picture, was little used until the advent of electronic computers in the 1950s due to the much greater computational demands over the early Hartree method and empirical models. Initially, both the Hartree method and the Hartree-Fock method were applied exclusively to atoms, where the spherical symmetry of the system allowed one to greatly simplify the problem. These approximate methods were (and are) often used together with the central field approximation, to impose that electrons in the same shell have the same radial part, and restricting the variational solution to be a spin eigenfunction. Even so, solution by hand of the Hartree-Fock equations for a medium sized atom were laborious; small molecules required computational resources far beyond what was available before 1950.

The Fock Operator
Because the electron-electron repulsion term of the electronic molecular Hamiltonian involves the coordinates of two different electrons, it is necessary to reformulate it in an approximate way. Under this approximation, (outlined under Hartree-Fock algorithm), all of the terms of the exact Hamiltonian except the nuclear-nuclear repulsion term are re-expressed as the sum of one-electron operators outlined below. The "(1)" following each operator symbol simply indicates that the operator is 1-electron in nature.

 * $$\hat F[\{\phi_j\}](1) = \hat H^{core}(1)+\sum_{j=1}^{n/2}[2\hat J_j(1)-\hat K_j(1)]$$

where:

 * $$\hat F[\{\phi_j\}](1)$$

is the one-electron Fock operator generated by the orbitals $$\phi_j$$ ,

 * $$\hat H^{core}(1)=-\frac{1}{2}\nabla^2_1 - \sum_{\alpha} \frac{Z_\alpha}{r_{1\alpha}}$$

is the one-electron core Hamiltonian,

 * $$\hat J_j(1)$$

is the Coulomb operator, defining the electron-electron repulsion energy due to the orbital of the j-th electron,

 * $$\hat K_j(1)$$

is the exchange operator, defining the electron exchange energy. Finding the Hartree-Fock one-electron wavefunctions is now equivalent to solving the eigenfunction equation:

$$\hat F(1)\phi_i(1)=\epsilon_i \phi_i(1)$$

where $$\phi_i(1)$$ are a set of one-electron wavefunctions, called the Hartree-Fock Molecular Orbitals.

Linear Combination of Atomic Orbitals
Typically, in modern Hartree-Fock calculations, the one-electron wavefunctions are approximated by a Linear combination of atomic orbitals. These atomic orbitals are called Slater-type orbitals. Furthermore, it is very common for the "atomic orbitals" in use to actually be composed of a linear combination of one or more Gaussian-type orbitals, rather than Slater-type orbitals, in the interests of saving large amounts of computation time.

Various basis sets are used in practice, most of which are composed of Gaussian functions. In some applications, an orthogonalization method such as the Gram-Schmidt process is performed in order to produce a set of orthogonal basis functions. This can in principle save computational time when the computer is solving the Roothaan-Hall equations by converting the overlap matrix effectively to an identity matrix. However in most modern computer programs for molecular Hartree-Fock calculations this procedure is not followed due to the high numerical cost of orthogonalization and the advent of more efficient, often sparse, algorithms for solving the generalized eigenvalue problem, of which the Roothan-Hall equations are an example.

Hückel
The Hückel method or Hückel molecular orbital method (HMO) proposed by Erich Hückel in 1930, is a very simple LCAO MO Method for the determination of energies of molecular orbitals of pi electrons in conjugated hydrocarbon systems, such as ethene, benzene and butadiene. It is the theoretical basis for the Hückel's rule; the extended Hückel method developed by Roald Hoffmann is the basis of the Woodward-Hoffmann rules. It was later extended to conjugated molecules such as pyridine, pyrrole and furan that contain atoms other than carbon, known in this context as heteroatoms.

Mathematics of the Hückel Method
The Hückel method can be derived from the Ritz method with a few further assumptions concerning the overlap matrix S and the Hamiltonian matrix H.

It is assumed that the overlap matrix S is the identity Matrix. This means that overlap between the orbitals is neglected and the orbitals are considered orthogonal. Then the generalised eigenvalue problem of the Ritz method turns into an eigenvalue problem.

The Hamiltonian matrix H = (Hij) is parametrised in the following way:

Hii = α for C atoms and α + hA β for other atoms A.

Hij = β if the two atoms are next to each other and both C, and kAB β for other neighbouring atoms A and B.

Hij = 0 in any other case

The orbitals are the eigenvectors and the energies are the eigenvalues of the Hamiltonian matrix. If the substance is a pure hydrocarbon the problem can be solved without any knowledge about the parameters. For heteroatom systems, such as pyridine, values of hA and kAB have to be specified.

Huckel Solution of Ethylene
In the Hückel treatment for ethylene, the molecular orbital $$\Psi\,$$ is a linear combination of the 2p atomic orbitals $$\phi\,$$ at carbon with their ratio's $$c\,$$:
 * $$\ \Psi = c_1 \phi_1 + c_2 \phi_2$$

This equation is substituted in the Schrödinger equation:
 * $$\ H\Psi = E\Psi$$

with $$H\,$$ the Hamiltonian and $$E\,$$ the energy corresponding to the molecular orbital to give:
 * $$Hc_1 \phi_1 + Hc_2 \phi_2 = Ec_1 \phi_1 + Ec_2 \phi_2\,$$

This equation is multiplied by $$\phi_1\,$$ and integrated to give new set of equations:
 * $$c_1(H_{11} - ES_{11}) + c_2(H_{12} - ES_{12}) = 0 \,$$
 * $$c_1(H_{21} - ES_{12}) + c_2(H_{22} - ES_{22}) = 0 \,$$

where:
 * $$H_{ij} = \int dv\phi_iH\phi_j\,$$
 * $$S_{ij} = \int dv\phi_i\phi_j\,$$

All diagonal Hamiltonian integrals $$H_{ii}\,$$ are called coulomb integrals and those of type $$H_{ij}\,$$, where atoms i and j are connected, are called resonance integrals with these relationships:
 * $$H_{11} = H_{22} = \alpha \,$$
 * $$H_{12} = H_{21} = \beta \,$$

Other assumptions are that the overlap integral between the two atomic orbitals is 0
 * $$S_{11} = S_{22} = 1 \,$$
 * $$S_{12} = 0 \,$$

leading to these two homogeneous equations:
 * $$c_1(\alpha -E) + c_2(\beta) = 0 \,$$
 * $$c_1\beta + c_2(\alpha - E) = 0 \,$$

with a total of five variables. After converting this set to matrix notation:

\begin{vmatrix} \alpha - E & \beta \\ \beta & \alpha - E \\ \end{vmatrix} * \begin{vmatrix} c_1 \\ c_2 \\ \end{vmatrix}= 0 $$ the trivial solution gives both wavefunction coefficients c equal to zero which is not useful so the other (non-trivial) solution is :

\begin{vmatrix} \alpha - E & \beta \\ \beta & \alpha - E \\ \end{vmatrix} = 0 $$ which can be solved by expanding its determinant:
 * $$\beta(\alpha - E) + (\alpha-E)^2 - (\beta(\alpha - E) + \beta^2 = 0\,$$
 * $$(\alpha-E)^2 = \beta^2\,$$
 * $$\alpha-E = \pm\beta\,$$

or
 * $$E = \alpha \pm \beta \,$$

and

 * $$\Psi = c_1(\phi_1 \pm \phi_2) \,$$

After normalization the coefficients are obtained:

 * $$ c_1 = c_2 = \frac{1}{\sqrt{2}},$$

The constant β in the energy term is negative and therefore α + β is the lower energy corresponding to the HOMO and is α - β the LUMO energy.

Tight-Binding
In the tight binding model, it is assumed that the full Hamiltonian $$H$$ of the system may be approximated by the Hamiltonian of an isolated atom centred at each lattice point. The atomic orbitals $$\psi_n$$, which are eigenfunctions of the single atom Hamiltonian $$H_{at}$$, are assumed to be very small at distances exceeding the lattice constant. This is what is meant by tight-binding. It is further assumed that any corrections to the atomic potential $$\Delta U$$, which are required to obtain the full Hamiltonian $$H$$ of the system, are appreciable only when the atomic orbitals are small. A solution to the time-independent single electron Schrödinger equation $$\Phi$$ is then assumed to be a linear combination of atomic orbitals $$\ {\psi}_n$$

 * $$\Phi(\vec{r}) = \sum_{n,\vec{R}} b_{n, \vec{R}}\ \psi_n(\vec{r}-\vec{R})$$,

where n refers to the n-th atomic energy level and $$^$$ is an atomic site in the crystal lattice.

Using this approximate form for the wavefunction, and assuming only the m-th atomic energy level is important for the m-th energy band, the Bloch energies $$\varepsilon_m$$ are of the form

 * $$\varepsilon_m(\vec{k}) = E_m - {\beta_m + \sum_{\vec{R}\neq 0} \gamma_m(\vec{R}) e^{i \vec{k} \cdot \vec{R}}\over {b_{m,\vec{R}}} + \sum_{\vec{R}\neq 0} \alpha_m(\vec{R}) e^{i \vec{k} \cdot \vec{R}}}$$,

where $$E_m$$ is the energy of the $$m$$th atomic level,

 * $$ \beta_m = -\int \psi_m^*(\vec{r})\Delta U(\vec{r}) \Phi(\vec{r}) d\vec{r}$$,

 * $$ \alpha_m(\vec{R}) = \int \psi_m^*(\vec{r}) \Phi(\vec{r}-\vec{R}) d\vec{r}$$,

and

 * $$ \gamma_m(\vec{R}) = -\int \psi_m^*(\vec{r}) \Delta U(\vec{r}) \Phi(\vec{r}-\vec{R}) d\vec{r}$$

are the overlap integrals.

The tight-binding model is typically used for calculations of electronic band structure and energy gaps in the static regime. However, in combination with other methods such as the random phase approximation (RPA) model, the dynamic response of systems may also be studied.

Bloch Theorem
A Bloch wave or Bloch state, named after Felix Bloch, is the wavefunction of a particle (usually, an electron) placed in a periodic potential. It consists of the product of a plane wave envelope function and a periodic function (periodic Bloch function) $$u_{nk}(r)$$ which has the same periodicity as the potential:

 * $$\psi_{n\mathbf{k}}(\mathbf{r})=e^{i\mathbf{k}\cdot\mathbf{r}}u_{n\mathbf{k}}(\mathbf{r}).$$

The result that the eigenfunctions can be written in this form for a periodic system is called Bloch's theorem. The corresponding energy eigenvalue is Єn(k)= Єn(k + K), periodic with periodicity K of a reciprocal lattice vector. Because the energies associated with the index n vary continuously with wavevector k we speak of an energy band with band index n. Because the eigenvalues for given n are periodic in k, all distinct values of Єn(k) occur for k-values within the first Brillouin zone of the reciprocal lattice.

More generally, a Bloch-wave description applies to any wave-like phenomenon in a periodic medium. For example, a periodic dielectric in electromagnetism leads to photonic crystals, and a periodic acoustic medium leads to phononic crystals. It is generally treated in the different forms of the dynamical theory of diffraction.

The plane wave wavevector (or Bloch wavevector) k (multiplied by the reduced Planck's constant, this is the particle's crystal momentum) is unique only up to a reciprocal lattice vector, so one only needs to consider the wavevectors inside the first Brillouin zone. For a given wavevector and potential, there are a number of solutions, indexed by n, to Schrödinger's equation for a Bloch electron. These solutions, called bands, are separated in energy by a finite spacing at each k; if there is a separation that extends over all wavevectors, it is called a (complete) band gap. The band structure is the collection of energy eigenstates within the first Brillouin zone. All the properties of electrons in a periodic potential can be calculated from this band structure and the associated wavefunctions, at least within the independent electron approximation.

A corollary of this result is that the Bloch wavevector k is a conserved quantity in a crystalline system (modulo addition of reciprocal lattice vectors), and hence the group velocity of the wave is conserved. This means that electrons can propagate without scattering through a crystalline material, almost like free particles, and that electrical resistance in a crystalline conductor only results from things like imperfections that break the periodicity.

It can be shown that the eigenfunctions of a particle in a periodic potential can always be chosen this form by proving that translation operators (by lattice vectors) commute with the Hamiltonian. More generally, the consequences of symmetry on the eigenfunctions are described by representation theory.

The concept of the Bloch state was developed by Felix Bloch in 1928, to describe the conduction of electrons in crystalline solids. The same underlying mathematics, however, was also discovered independently several times: by George William Hill (1877), Gaston Floquet (1883), and Alexander Lyapunov (1892). As a result, a variety of nomenclatures are common: applied to ordinary differential equations, it is called Floquet theory (or occasionally the Lyapunov-Floquet theorem). Various one-dimensional periodic potential equations have special names, for example, Hill's equation:

 * $$\frac {d^2y}{dx^2}+\left(\theta_0+2\sum_{n=1}^\infty \theta_n cos(2nx) \right ) y=0 $$

where the θ's are constants. Hill's equation is very general, as the θ-related terms may viewed as a Fourier series expansion of a periodic potential. Other much studied periodic one-dimensional equations are the Kronig-Penney model and Mathieu's equation.

Chemically Conjugated Systems
A chemically conjugated system is a system of atoms covalently bonded with alternating single and multiple (e.g. double) bonds (e.g., C=C-C=C-C) in a molecule of an organic compound. This system results in a general delocalization of the electrons across all of the adjacent parallel aligned p-orbitals of the atoms, which increases stability and thereby lowers the overall energy of the molecule.

The electron delocalization creates a region where electrons do not belong to a single bond or atom, but rather a group. An example would be phenol (C6H5OH, benzene with hydroxyl group) (diagramatically has alternating single and double bonds), which has a system of 6 electrons above and below the flat planar ring, as well as around the hydroxyl group.


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Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Jukka. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Jukka~enwikiversity that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:40, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 06:12, 19 April 2015 (UTC)

title: User talk:Jukka~enwikiversity


text:
User talk:Sangeeta BG

Hi Sangeeta and other KOIIAns!

I've found your project on Wikiversity today because I noticed Karin's edits to a couple of your pages, and I've noticed that you guys haven't really been in contact with the rest of the Wikiversity community. I've written a section about your project at the Wikiversity Colloquium, the central meeting place of the Wikiversity community, and I've added an message box to your pages at Wikiversity so that English-speaking people have some context to understand what is going on when they see a Swedish page. Could you have a look at what I've written at the Colloquium page and weigh in and correct any mistakes I've made? Thanks!

In any case, it's cool to have you here! Med vänliga hälsningar, Benja 20:40, 4 April 2008 (UTC)

INTERSECTIONALITY 08:22, 25 February 2008 (UTC)==We Own This Course== My idea is that we together create a resource at Wikiversity on the theme of our course

The resource can be seen as the examination for this course! Each of the participants could have their own space OR you could in pairs or in a whole group edit a final version as a LEARNING RESOURCE for others. A suitable example to look at is the resource that has been created by a group of students at the resource Queer Studies]. Check that out.

 * The resource that is created at our page can be in Swedish and/or in English; we can also have sections of the resource in Swedish Sign Language, SSL and/or American Sign Language, ASL

 * We can start putting up ideas for KOIIA - 2 inside our resource

 * We can start putting up tips for litterature specifically linking up intersectionality and education KOIIA - 2 literature list

 * our portals, schools, and research activities;

Sara F 09:55, 28 February 2008 (UTC)A suggestion: perhaps we can make a link here Gemensam text where we can begin to write a text together. If I put a text here I do want you people to contribute to it, not just add comments. The texts that I consider being finished or do not wish to have edited remain at my own page.

 * Olivers sida

 * Karins sida

 * Maries sida

 * [Jennys sida http://en.wikiversity.org/wiki/User_talk:Jenny_Rosen_Gomez]

 * [Saras sida http://en.wikiversity.org/wiki/User:Sara_F]

 * Catarinas sida

 *  Annaliinas sida

On this page we want to discuss central concepts in the literature concept discussion

 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Gbaor 06:26, 22 January 2008 (UTC)

6 mars 2008

Idag kom vi överens om att alla ska studera hela Linell (2005) och kap 2 & 3 i Linell (1998) tills den 24 april. Därutöver ska var och en välja ut ytterligare 2 kap från Linell (1998). Läsloggar ska finnas på vår resurssida (d v s på era egna sidor som är länkad hit) när ni är klara dock senast söndag 20 april. Litteraturen ska presenters vid seminariet torsdag den 24 april parvis alt individuellt (upplägget som vi hade under seminariet idag föreslår jag; hör av er om ni har andra förslag för att strukturera seminariet).

Under tiden frams tills nästa seminariet ska vi även arbeta med begrepp (inspirerad från Davis, Hornberger och litteratur om Intersektionalitet).

Därutöver ska vi börja bearbeta de teoretiska resonemang (särskild figurer) som presenteras i Hornberger. Förslagsvis kan detta sättas in under länk gemensam text (se under Saras inlägg här uppe på sidan).

Jag utgör ifrån att ni alla ska bidra aktivt till dessa olika sidor.

Jag har idag även utvidgat vår sida på about Sangeeta BG. Där finns en lista över oss alla och var och en av oss ska länka upp våra namn till egen hemsida.

''Lycka till med allt detta. Jag ser fram emot att träffa er HÄR på våra gemensamma lärande resurs!''

Sangeeta BG 13:43, 6 March 2008 (UTC)

Val av texter till 24 april

Vi har ju i uppdrag att välja 2 kap från Linell 1998 att arbeta med parvis. Jag tycker att kap 11 & 12 var särskilt intressanta och arbetar gärna med dessa tillsammans med någon. Så om någon mer är intresserad av dessa så kan vi börja vår gemensamma text här Linnel kap 11 & 12 Jenny R

Mitt bidrag till läsning av Linells bok (1998) skulle kunna vara kap. 6,7 och 8. //Karin

title: User talk:Sangeeta BG


text:
User talk:Norman the Tank Engine~enwikiversity

Welcome
Hello Norman the Tank Engine, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Gbaor 06:26, 22 January 2008 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Norman the Tank Engine. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Norman the Tank Engine~enwikiversity that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:40, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 06:17, 19 April 2015 (UTC)


text:
User talk:Kim Trouwborst

Welcome
Hello Kim Trouwborst, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Gbaor 06:26, 22 January 2008 (UTC)

title: User talk:Kim Trouwborst


text:
User talk:Benjism89

Welcome
Hello Benjism89, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Gbaor 06:26, 22 January 2008 (UTC)

title: User talk:Benjism89


text:
User talk:Fruggo

Welcome
Hello Fruggo, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Gbaor 06:26, 22 January 2008 (UTC)

title: User talk:Fruggo


text: User:Bellayet/Survey responses

title: User:Bellayet/Survey responses


text:
Category:Biochemistry Exam Study Guide

University of Wisconsin School of Medicine and Public Health

Biochemistry Exam 2 Study Guide

title: Category:Biochemistry Exam Study Guide


text:
Glass

This area is about learning, teaching, and research related to glass.

Research questions

 * How can stronger glasses be created?
 * What are some uses of glass?

Local
Here are some local learning ideas on this wiki.

 * School:Art and Design
 * Materials science
 * Filmmaking Basics/Camera Lenses
 * Building construction techniques
 * Physics
 * /Glass art/
 * /Glass blowing/

Wikipedia readings

 * Glass
 * Glass production
 * Sand
 * Calculation of glass properties
 * Glass databases
 * Aluminium oxynitride
 * Category:Glass

Videos

 * How Glass is Made
 * How is glass made?
 * Primitive Glassmaking (Creating Glass from Sand)
 * See How Window Glass Is Made The Artisinal Way
 * How Sand Made From Crushed Glass Rebuilds Louisiana’s Shrinking Coast

title: Glass


text:
User talk:Bellayet

Welcome
Hello Bellayet, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! --Gbaor 14:14, 22 January 2008 (UTC)

Wikimedian Demographics update
Hello Bellayet. I'm writing because you requested a reminder about progress on Wikimedian Demographics. For the time being these will be about once per month.

Speaking of reminders, it turns out the template question isn't the most efficient way of coming up with a mailing list. If you want to recieve this message on another of your talk pages (or don't want them at all), please edit the list on Wikimedian Demographics/Reminders.

To update on progress so far, there have been somewhere around 50 respondents over the past month, with more trickling in slowly but steadily. There are 7 major surveys (or 12, depending on how you count them):
 * 1) The basic survey (about your participation in Wikimedia)
 * 2) The "geography" surveys (actually 6 of those, for each inhabited continent)
 * 3) The Operating System survey (still stubby)
 * 4) The Wikipedia survey
 * 5) The Commons survey
 * 6) The US presidential elections survey
 * 7) The sexuality and relationships survey

Only the geography surveys have had any major modifications since being originally posted (more countries were added to those).

Several new surveys have been discussed at Talk:Wikimedian Demographics, as well as other places within Wikiversity. A few that might be ready sometime in February include:
 * A survey about Women in Wikimedia
 * A survey about Wikibooks
 * A survey about Wikiversity
 * A survey about administrative issues (including cross-wiki topics such as CheckUser and "global blocking")
 * A survey about environmental issues
 * A survey about religion
 * A survey about international trade

If you have ideas for more surveys, please share them on Talk:Wikimedian Demographics. Thanks for your participation thus far, and we hope to see you soon! --SB_Johnny | talk 11:50, 5 February 2008 (UTC)

title: User talk:Bellayet


text: Template:Recovery psychology

title: Template:Recovery psychology


text:
User talk:GirishPandit

Welcome
Hello GirishPandit, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! Erkan Yilmaz ( Wikiversity:Chat, wiki blog ) 23:33, 22 January 2008 (UTC)

title: User talk:GirishPandit


text:
User talk:Lenny.love

Welcome
Hello Lenny.love, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. To get started, you may
 * Take a guided tour and learn to edit;
 * Explore our learning projects;
 * Browse our portals, schools, and research activities;
 * Read and help develop our community policies；or
 * Chat with other Wikiversitans on #wikiversity-en.

And don't forget to explore Wikiversity with the links to your left. Be bold, and see you around Wikiversity! Erkan Yilmaz ( Wikiversity:Chat, wiki blog ) 23:34, 22 January 2008 (UTC)

title: User talk:Lenny.love


text:
Second Life/Second Life Architectural Building Tutorial

Welcome. This is a tutorial for learning how to build in Second Life (SL). Second Life is a internet based virtual world. You can create a personalized "avatar" and use that "person" to travel around the Second Life world, to interact with other avatars, to build things and to teach things to others.

This tutorial is designed for architecture students who have not used Second life before, but may use it as part of their studies and profession. In this lesson you will learn how to log in to SL and how to use the most common building tools now available in SL. These include how to move around, change your view, create objects, position objects and edit objects.

To learn these skills you will first view a video showing some of the advanced things that can be done in SL and then follow a text-based tutorial that will guide you through creating your first object in SL, a simple building. Once you have learned how to do this you may wish to learn more things on your own in Second Life.

Get started

 * 1) View this 90 second video to give you an idea of how some architects are using SL. http://www.youtube.com/watch?v=R7bXu2ozXo0 (This video should open in a new window or tab, when you are done watching it close it to get back to this page.)
 * 2) Complete this pre-instructional survey to help us understand what your internet and SL experiences have been so far.
 * 3) Now you are ready to create an SL account and begin the Tutorial that will enable you to build your own structure.

Create an Account

 * 1) Open a new browser window and go to www.secondlife.com
 * 2) Click on the orange "JOIN NOW" button in the top left of the screen.
 * 3) Follow the registration instructions:
 * 4) Choose "Skip This Step" at the bottom of the Select a Community page.
 * 5) Enter the basic details requested on the sign up page.
 * 6) *Avatar Name, first and last. This will be the name people in SL know you by. It can not be changed, so choose wisely.
 * 7) **Short is good
 * 8) **If you want people to know who you really are use your real first and last name as your SL first name and pick a short last name (i.e. Jun or Hax)
 * 9) **Check if name is available
 * 10) **Date of birth (must be over 18)
 * 11) **Email for verification of account
 * 12) Select an Avatar.
 * 13) *Your avatar is your virtual body. Select the one you want to look like. You can always edit this later.
 * 14) Welcome (Final Details).
 * 15) *This is all the standard stuff.
 * 16) Upgrade to Premium.
 * 17) *Skip this step
 * 18) Download.
 * 19) Select the version for your operating system
 * 20) *You should know how to install downloaded software on your computer.
 * 21) *If not get some help from a friend who knows how to do this..

Download and Install Second Life Client Software

 * 1) Download the client http://secondlife.com/download
 * 2) *This should open a second browser window so you can see both this Tutorial and SL at the same time. If this does not happen automatically you may need to open a New Window manually.
 * 3) *Follow the instructions on the website to Install the Second Life Client.

Go to our Outdoor Classroom

 * 1) Go to www.chrsys.com/sl
 * 2) Click on the orange 'teleport now' button.
 * 3) *This should open the second life client. You may have to click on "Launch application" and ignore the "loading" message.
 * 4) Type in your Second Life first and last name, and password in the bottom left of the Second Life screen.
 * 5) Click "Connect"
 * 6) *Wait while SL verifies your protocol, logs you in and connects you. Be patient. This may take some time.
 * 7) *After Second Life finishes logging you in, you should be in the classroom.
 * 8) If you see a map instead, you have to click on the "teleport' button in the bottom right corner of the map window.

Explore the houses on the cliff
Explore the two houses on the cliff by using the up, down, right, left arrows on the keyboard to move your avitar around. When you are through exploring the house on the cliff... Go to the open foundation and stand in front of it. The foundation is the square slab on the ground between the two houses. You are now ready to learn how to use the basic SL tools.

Create your first object
Right click (apple click) on the ground. This reveals the Context menu Select 'Create' (or click the 'Build' button at the bottom of the screen) (Occasionally SL gives you some tips that you can use or ignore.) This should cause the 'Build" window to appear with the 'Create' button selected. The mouse cursor should change to the "Build" wand Click on the ground in front of you to "rez" (Create) a box. This rezes a half meter square cube with a plywood 'texture' The box starts off in 'Edit' mode. This is shown by the 'Edit' button being selected in the 'Build' window By default the 'Position' tool is selected. The mouse has has four directional arrows next to it with red, green and blue "Position" handles

== Move, rotate, stretch and drag objects. Move the box in all three directions using the "Handles" by clicking the arrow head to move the object along that axis. each color corresponds to an axis (red(x)= east/west, green(y)= north/south, blue(z)= up/down) Rotate the box by holding down the 'Control' key or select 'Rotate' from the 'Build > Edit" menu. The "Handles" change to allow holding onto a ring to rotate around each axis. Stretch the box by holding down "Control + Shift" (or select "Stretch' from the Build > Edit menu) and changing the dimensions of the box in all three directions. Drag the object by grabbing the grey Handles and resizing the box proportionally. Practice all four tools (move, rotate, stretch and drag) on this box until you are comfortable with using these tools

Control the Camera
While you are working you may want to change your view. While you can use the arrow keys to walk around and do this, there is another way that many find easier and more useful. This is done with the camera controls. Go to the 'View' menu on the top of your screen and select 'Camera Controls' to bring up the camera control window. (It may be hidden off screen so you might have to drag it into view) Rotate the camera view by clicking on the arrows in the left circle to rotate the camera view. Zoom the camera view by clicking on the '+' and '-' signs to zoom the camera view in and out. Pan the camera view by clicking on the arrows in the right circle to pan the camera view 1. You can also use the keyboard shortcuts to control the camera as instructed below: Zoom the camera by holding down the 'alt' key and use the mouse click to zoom (up and down) and pan (left and right) Rotate the camera view by holding down the 'alt' and 'control' keys and use the mouse click to rotate the camera view. Pan the camera view by holding down the 'alt', 'control' and 'shift' keys and using the mouse click to pan Practice using the camera until you are comfortable with using the camera. 1.: If you can get used to the keyboard short cuts it will make building much easier.

At his point you have learned the basic tools to build objects and change your view as you are building.

Play with these tools until you feel comfortable with each of them before moving on to the next step.

Start Building
Delete any object you have created up to this point Delete an object by going to the Edit mode. Right click (apple click) on an object and select 'Edit' or click the 'Edit' button in the build menu. Hit the Delete key (not the backspace key) or right click (apple click) on the object and select 'More' and then 'Delete'. Create and Position a new box. Go to Build and clicking your mouse on the ground. With the Build window open, click on the 'Object' tab. If the object tab is not visible, click the 'More' button to expand the Build window. Click on your box to select it for editing. Find the Position and Size cells on the left Enter the x,y,z coordinates for Position and Size. This will position the box on the platform and size it for your house. The Position should be:
 * x = 145m
 * y = 230m
 * z = 24m

The Size should be:
 * x = 5m
 * y = 5m
 * z = 2.75m

Hollow the box and create a door. Open the "Build" window and click on the 'Object' tab in the build window. Type "95" in the 'hollow' input field and hit the Enter key. Use the up and down arrows on the 'Path Cut' section. Enter a Begin (B) value and an End (E) value to make an opening in the wall for the door. Create and Position a roof. Select the 'Create' button and select the pyramid prim (3rd from the left). Change its size and position so it looks like a roof to your building. 6m x 6m x 2m works well Enter the same x and y position as for the walls you made.
 * x = 145m
 * y = 230m

Even though the roof has a larger footprint, SL will center it on the position you enter Use the 'Position' tool for the z axis to slide the roof to a position slightly above where you can see the wall protruding though the roof. Congratulations! You have not completed a basic structure in SL. Walk around and inside the structure to see how it looks and feels.

Apply texture
You may have noticed that your building is not as pretty as the one next to it. This has a lot to do with the textures. To add textures to your building. Select the wall of your building and click on the "Texture" tab in the "Build" menu. Click on the Texture thumbnail on the left. This will open a new Texture window. Browse the window on the right to Library > Textures > Altoll Textures You will see a lot of  the textures you can use for your sample building. Find the "Altoll Shack Wall1" texture or try different ones to see what you like. I suggest using one with windows in it like "Altoll Shack Wall1." Select the roof of your structure Select a roof texture.

Congratulations! You have build your first building in Second Life. Please help us with improving this instructional model by taking this exit survey.


text:
User:GirishPandit

Hi,

I am Girish Pandit and over 10 years of IT experience and various technologies and I would like to help community by sharing knowledge.

Thanks everyone for keep it up!

title: User:GirishPandit


text:
Water

Water is an inorganic chemical compound with the molecular formula H2O. This learning resource starts with an example of a Solar Seawater Still (SSS) and guides the learner through chemical and physical properties that are necessary to understand SSS, refers to sea water and drinking water in the example and introduces to the effects of pollution of water on health. Further readings to that

Desalination – Solar Seawater Still (SSS)
Desalination – Solar Seawater Still (SSS): Water is a precious resource especially in dry areas. In hot and dry areas the sun provides the heat for evaporation. On the right can be seen a diagram of a seawater still, that distills fresh water from salty seawater.
 * Explain how a Solar Seawater Still works!
 * Analyse the background of Solar Stills and suggest improvements to the setup (e.g. fresh water collector directly under the seawater container).
 * Measure temperature differences in soil according to depth (underground). If the temperature difference is high between surface temperature and depth of fresh water collector condensation works better. Try to build your own Solar Still and collect data about the amount of fresh water retrieved from the SSS per hour with certain environmental conditions.
 * Upload snapshots about your Solar Seawater Still (SSS) on Wikiversity and explain how you collected data with your experimental design.
 * Look for areas on the globe, where your Solar Seawarter Still could be applied (availability of seawater, not enough or contaminated freshwater, temperature conditions).
 * (Windpump and Seawater Transport) With wind energy sea water could be transported from coastal areas to hot arid zones, that have no direct access to seawater. Analyse possibilities of transporting sea water to hot desert regions on the globe. Does that extend the geographical areas of application for your SSS? Create an SSS application map with OpenLayers, which shows areas on a heatmap where the areas in red are the hot areas which can benefit from Solar Seawater Stills.
 * (Solar Water DISinfection SODIS) Compare the concept of an Solar Still with Solar Water Disinfection ! What are similarities and differences between those concepts?

Farming
Explain the impact of climate change on agriculture. Describe the link between the heat stress to plants and the availability of water. Precision farming includes the water management. Explain the requirements and constraints of a sustainable water and soil management for farming (e.g. storing of water in the soil, compression of soil due to heavy truck and tractors, shades of plants in different heights that reduce evaporation,...).

Chemical and Physical properties
Analyse the chemical and physical properties of water and explain why they are relevant to the comprehension of the Solar Water Still.

Effects of Water on Life
Study the effects of water on life. The Solar Water Still is just one method to provide the necessary water for a community.
 * What other sources of water exist to allow plants, animals and humans to survive? Are these sources sustainable for future generations?
 * Where is water necessary in the life cycle of plants, animals and humans? Explain in detail according to the biological background knowledge!
 * How does climate change alter the availabilty of drinking water? Which areas on the earth are most affected?

Health and Pollution
Water pollution of different types create a risk for human, animal and environmental health. Learn about Risk Management and apply that to water pollution and health. Pharmaceuticals are helpful in health services, but it is also a difficult task to remove them from waste water (see also Water:Health and Pollution).
 * Analyse the Solar Water Still in the image on right and try to explain why water can be considered as having been treated by the solar water still.
 * Can this water be used for a greenhouse? Evaporation removes also minerals from the water, is that a problem for drinking and/or for plants? Look for scientific evidence and add the evidence to this article and create further questions to explore this area!
 * Explain how to deal with the polluted sediments in the upper water container.

Sustainable Development Goals
Analyse the United Nations' concept of Sustainable Development Goals.
 * A preliminary approach will provide two SDGs which seem to refer to water. Systems Thinking applied on the topic of water will lead to many more SDGs which are effected by water. Try to analyse every single SDG and explain how water plays a role in the accomplishment of these goals.

Disaster Management
Extreme events due to climate change cause a higher probability of flood events. Flooding needs to be responded by disaster management. Capacity building will focus on modelling of flood events, planning response and preparedness activities and learning how space technology with freely available services (e.g. Copernicus) could support risk management strategies.

Learning Task
This learning resource focuses on how water is important for life on earth.
 * (Water Resources) There is a lot of water on earth but drinking water is scarce.
 * Determine the percentage of water available on earth, that can be used as drinking water.
 * Analyse the over-exploitation of fresh water and link commercial exploitation of ground water to access to water for the local population. Link this analysis to the Sustainable Development Goals and explain for every SDG, if and how water supply is linked to this goals
 * (Earth Water Simulation) Analyse available landsurface simulations for Water (e.g. Today's Earth - Water ) and explain how simulations can be generated based on available data.
 * Analyse the contamination of drinking water on earth. Explain sources of contamination of this precious resource -- drinking water.
 * (Global Warming) An important fraction of drinking water (find out how much) is locked in the polar ice and ice in glaciers.
 * Try to find out how much drinking water we might lose if global warming causes the polar ice and the ice in glaciers to melt.
 * Perform a basic Risk Management for regions on earth which might be affected by a rise in the mean sea levels. What part of this coastal population, might this rise in sea levels, compel to migrate inland to higher ground?
 * Explain the impact of water evaporation in the context of global warming.
 * (Rivers, Hydrology and Tsunami) Watch the video taken at the river Rhine and analyze the impact of ship passing by. Compare at first the time index 2:00 and the time index 4:00 in the video and then watch the video from the beginning and try to identify when you would expect the rise of the water level of the river. Compare that with the File:Tsunami 20110311 Kita-Ibaraki Japan.ogv|Tsunami Video in Japan]] on the right. What are similarities and differences between those video from the river Rhine and the Tsunami in Japan?
 * (Mapping of Risk and Resources) Water is a precious resource that is necessary for survival of flora and fauna on earth.
 * Try to create heatmap by using OpenLayers and show where people on earth have enough clean drinking water. Mark areas as red if people do  not  have clean drinking water. Define semantics of the color scheme used in the heat map first and then try to find open data for creating such a map (see Spatial Risk Management and Water Resource Management).
 * (Chemical Formula) The following questions analyse the topic "water" from the angle of chemistry:
 * Why is this inorganic compound with the molecular formula H2O so stable?
 * If you burn hydrogen heat is generated (Link History: Zeppelin Hindenburg at Lake Hurst) and the product is water. Why is heat generated? What lighted the hydrogen in the Zeppelin, so that water was generated? Why could the generated water not extinguish the fire in the exploding Zeppelin?
 * You can generate water by using hydrogen and oxygen in a fuel cell. This electrochemical cell converts the chemical energy from a fuel into electricity through an electrochemical reaction. Analyse the chemical processes. How can this concept be employed for Electric Mobility? Analyse the quantity of water production and determine whether that concept will be able to produce water as a resource.
 * Explore why water exists on our planet in such great abundance, in contrast to the far less quantity of gold! The answer to this question could lead, via modern Physics to the Big Bang!
 * (Saline) Look at the Salines e.g. in France and combine the concept with Solar Water Still and analyse the economic impact in conjunction with fresh water supply in arid/dry zones.
 * (Rainwater harvesting) Due to climate change extreme events become more likely. On the other side there can be location in the dry periods inbetween become warmen. Rainwater harvesting could be one approach to collect water during rainy seasons and use the water in dry periods.
 * (Refugee Camps - Supply Chain Management) Water is basic resource, we need in cover in a supply chain. Try to estimate how much water is necessary per person per day in refugee camp
 * 2 liters of water,
 * 20 liters of water,
 * 120 liters of water or
 * more than 200?
 * Calculate your own water consumption per day per member of the familiy (including drinks, washing, plants, ... and compare that with your estimates in a refugee camp. In dry zone the supply with clean water for a large number of people is a big challenge. Explore options to cover the need for water and analyse the methods of supply chain management!

 * (Remote Sensing and Contamination of Water) Remote Sensing can be used to detect oil spills. Explain how radar satellite technology can help to detect the oil spills. What a potential cause for
 * false positive and/or
 * false negative detection
 * of oil spills?

 * (Water and Energy Supply) Waves on the ocean can be source of energy? Explain how wave power be "harvested" as sustainable green energy? What other links exist between water and energy?
 * (Precision Global Health) Water is crucial for health and well-being. Analyse the link between access to water, health and the concept of Precision Global Health.

Target Groups

 * (Primary Schools) Explore water evaporation and condensation in a pot on a stove. This can be explored by a video recorded with a smartphone in the kitchen and shared/presented on a data projector in school. Pupils should explain what they observe. Use salty water in pot and condensed water. Taste of cold salted water should be compared with the taste of collected condensed water (taste the salt removal).
 * (Secondary Schools) Explore physical and chemical properties of water according to evaporation and condensation (curriculum). Energy consumption of the stove. Refer to Solar Water Still and Green Energy.
 * (Engineering) Optimize technical design of Solar Water Still.
 * (Physics University) Modelling of Fresh Water production of Solar Water Still (Bachelor of Science).
 * (Geography/Spatial Analysis) Where are solar water still necessary and applicable - create a risk map for fresh water shortage and resource supply map for solar water stills and integrate both.
 * (Teacher Education Mathematics) Mathematical Modelling, train teachers to apply SDG assigned learning resources and develop them (see Reader2Author)

title: Water


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