OpenLLM-France/wikimedia huggingface dataset:
# Circuit Idea/Specific Circuit Questions
## List of specific circuit questions
### Passive Voltage-to-Current Converter

What is the cause and effect relation in a voltage-supplied Ohm's circuit? What does the resistor convert here - energy or information? Is the circuit reversible (can we swap circuit inputs and outputs)? How does a series connected load affect the circuit? How can we decrease the error caused by the load? How do we eliminate the error at all? Is there any relationship between this passive and the active version? If yes, how do we convert the passive version into an active one? What are the input and output resistances?

### Passive Current-to-Voltage Converter

What is the cause and effect relation in a current-supplied Ohm's circuit? What does the resistor convert here - energy or information? Is the circuit reversible (can we swap circuit inputs and outputs)? How does a parallel connected load affect the circuit? How can we decrease the error caused by the load? How do we eliminate the error at all? Is there any relationship between this passive and the active version? If yes, how do we convert the passive version into an active one? What are the input and output resistances?

### How do We Create Sinusoidal Oscillations?

How oscillations arise in nature? Why does an LC tank consist of two "heterogeneous" accumulating elements (a capacitor and an inductor)? Why is it not assembled by two "homogeneous" elements (both capacitors or both inductors)? What is the role of these elements in the LC circuit? What do they actually do there? What are they? Why does the energy in an LC tank "have no peace"? What make it circulate (in theory, infinitely) between the two components? What makes the accumulating elements discharge completely? Why does an LC oscillation have a sinusoidal shape? Why is it no with linear or other shape? Why does not the LC natural frequency depend on the amount of the "pushed" energy? Why is the oscillation curve symmetrical? What are the differences between LC and other (RC, relaxation, etc.) oscillations? Is there any likeness between them and what is it? What is the connection between an LC tank and a pendulum? What is the "capacitor" and what is the "inductor" in a pendulum?

## See also

Common Circuit Questions
# Cell Biology/Cytoskeleton/Actin Filaments
## Cytoskeleton

Cytoskeleton is the skeleton of the cell, constructed from proteins. They lie on cytoplasm, defining cell's shape, movement and many other functions. There are 3 types of them which we will discuss shortly.

## Actin filaments

Actin filaments are strings anchored one end in the plasma membrane. They generates contractile forces, which helps the cell moves and changes shape.
Actin filaments are also called microfilaments because they are the thinnest in cytoskeleton family.
# Cell Biology/Cytoskeleton/Intermediate Filaments
## Intermediate Filaments

Intermediate Filaments are the thickest in cytoskeleton family. Unlike microfilaments, they don't anchor to the plasma membrane. They move in the cytoplasm around the nucleus. Because they are the thickest, they serve an important role in the stability of the cell's shape, forming hair, skin, etc.
# Cell Biology/Cytoskeleton/Microtubules
## Microtubules

Microtubules as the name suggests is derived from two words- Micro means Small and Tubules means tube like. Microtubules comes under the class of organelles known as Cytoskeleton. Cytoskeletons are the frameworks of the Cell, that form the structural supporting components. Besides these they have other works like Cell movements, muscle contractions and in Cell division. Cytoskeletons are of three types viz, Microtubules, Intermediate filaments and Microfilaments. Microtubules are larger than the other two. Microtubules are composed of tubulin proteins. Tubulin are proteins that form the components of microtubules. The two main types of tubulins are Alpha and Beta tubulins. They form dimers. Microtubules are polymerized and depolymerized according to the cell's physiological status. They are strings radiating from points near the nucleus, called centrosomes. When the cell goes into mitosis (which means it's going to divide), these filaments separate into 2 groups, each one carries an equal number of condensed DNAs to each side of the cell. Therefore, each daughter cell has an equal number of DNAs. The number of DNAs is unique for each species.
* Prophase: The two round objects above the nucleus are the centrosomes. The chromatin has condensed.
* Prometaphase: The nuclear membrane has degraded, and microtubules have invaded the nuclear space. These microtubules can attach to kinetochores or they can interact with opposing microtubules.
* Metaphase: The chromosomes have aligned at the metaphase plate.
* Early anaphase: The kinetochore microtubules shorten.
* Telophase: The decondensing chromosomes are surrounded by nuclear membranes. Cytokinesis has already begun; the pinched area is known as the cleavage furrow.
# Cell Biology/Cell types/Archaea
## Archaea

Archaea are microbes that are more closely related to Eukaryotic cells than they are to the Bacteria (http://tolweb.org/tree/home.pages/aboutoverview.html). Under a light microscope, they visually resemble Bacteria, so that it wasn't until the advent of the use of molecular methods in evolutionary biology that they were recognized as belonging to their own Domain (a phylogenetic grouping above the level of Kingdom). Archaea have ultrastructural features that are superficially similar to those in Bacteria but are usually comprised of distinctive molecules. They do, for example, have a cell wall, yet that cell wall never contains peptidoglycan. Instead, peptidoglycan is a unique molecular signature of the Bacteria. Archaea also have odd lipids in their cell membranes. They were originally discovered living in extreme environments thought to resemble conditions on early earth, but now that microbiologists have become more adept at detecting them, it is clear that the Archaea are not confined to extreme habitats and can instead be found everywhere. It is true that some Archaea are "extremophiles," found in extremely salty or hot environments, but there are also extremophile Bacteria and even some very unusual extremophile Eukarya. The best-understood groups of Archaea are:
* Methanogens use Carbon dioxide and Hydrogen to make Methane. They are found in sewage, cows, and swamps, and they do not take in oxygen.
* Extreme Halophiles live in extremely salty places (i.e.: the dead sea and great salt lake).
* Thermoacidophiles prefer extremely hot, acidic areas (i.e.: hot springs and volcanos).
# Cell Biology/Cell types/Plant cells

Cell_biology | Types of cells
<< Eukaryotes | Unique Properties of Plant Cells
Plant Cells have a number of important differences compared to their animal counterparts. The major ones are the Chloroplasts, Cell walls and Vacuoles. Unlike animal cells, plant cells do not have centrioles.

## Chloroplasts

The chloroplasts are an organelle similar to the mitochondria in that they are self reproducing and they are the energy factories of the cell.they are near the large center vacuole. There most of the similarities ends. Chloroplasts capture light energy from the sun and convert it into ATP and sugar. In this way the cell can support itself without food.

## Vacuoles

Plants often have large structures containing water surrounded by a membrane in the center of their cells. These are vacuoles and act as a store of water and food (in seeds), a place to dump wastes and a structural support for the cell to maintain turgor. When the plant loses water the vacuoles quickly lose their water, and when plants have a lot of water the vacuoles fill up. In mature plants there is usually one large vacuole in the centre of the cell.

## Cell walls

Plant cells are not flaccid like animal cells and have a rigid cell wall around them made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin. The cellulose molecules are linear and provide the perfect shape for intermolecular hydrogen bonding to produce long, stiff fibrils. It is the cell wall that is primarily responsible for ensuring the cell does not burst in hypotonic surroundings.
# Cell Biology/Cell types

Cell Biology | Introduction | Types of cells | Parts of the cell | Cell division | Gene expression and translation

## Types of Cells

* Prokaryotes
* Eukaryotes
* Plant cells
* Bacteria
Cell Biology | Introduction | Types of cells | Parts of the cell | Cell division | Gene expression and translation
# Cell Biology/Cell types/Introduction to Bacteria
## Bacteria

Bacteria are prokaryotes, which means they are unicellular and have no nucleus. They come in various shapes: rodlike, spherical or spiral. Bacteria are very small. A typical one is only several micrometres in size. 1 billion could fit on 1 square centimeter of space on the human gums, and 1 gram of digested food has 10 billion bacteria.
Because they are such small organisms, light microscopes can only let us see their shape, and how they move. Under an electron microscope, we can see the details of their external parts and perhaps a blurred center due to their genetic material not being within a nucleus.
Bacteria have a cell wall that can be either thick or thin. The chemical test, the Gram Staining technique, can help a researcher to determine this characteristic for keying out and idenficaton purposes. A thin-walled bacteria will appear to be purple for a positive Gram-staining, while bacteria will be pink if they are Gram-negative.
Bacteria can have external locomotive structures called flagella or pilli. Locomotive structures are those that allow the organisms to move around in its environment.
Under ideal conditions, one bacterium duplicates itself in about 20 mins, i.e. every 20 minutes, the number of bacteria doubles. In one day, from one bacterium, it can reproduce to 2^72 new organisms (which is 4,722,366,482,869,645,213,696). In one 43 hours, their population is about 2^130 organisms. One bacterium weighs about 10$^{-12}$g. 2$^{130}$ bacteria weighs over 6 x 10$^{24}$ kg, which is the weight of the Earth!
Because they can reproduce so fast, their populations can adapt to new environments; they evolve to meet the demands of any new localized stressors. They can change so that they can use other substances as their food and can develop a resistance to antibiotics. An important note to the above calculation is it is often that those bacteria don't have enough food to reach that population. They also have a lot of enemies. They die as fast as they duplicate.
Bacteria belong to domain Eubacteria
# Chess Opening Theory/1. c4/1...c5/2. Nf3/2...Nc6/3. g3/3...g6
### 3...g6

White will play 4. Bg2 to justify the g3 push.
When contributing to this Wikibook, please follow the Conventions for organization.
# Chess Opening Theory/1. c4/1...c5/2. Nf3/2...Nc6/3. g3/3...g6/4. Bg2/4...Bg7
### 4...Bg7

White can either castle with 5. O-O or transpose into a popular line of the Symmetrical Variation with 5. Nc3.
When contributing to this Wikibook, please follow the Conventions for organization.
# Symmetrical English
### 2... Nf6
## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
| 3 | 4 | 5 |
| d4 cxd4 | Nxd4 e6 | Nc3 Nc6 | = |
| g3 b6 | Bg2 Bb7 | O-O g6 | += |
| Nc3 e6 | | | = |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
* This Chess related article is a stub. Please assist Wikibooks by expanding it.
# Chess Opening Theory/1. c4/1...c5/2. Nf3/2...Nc6/3. g3
### 3. g3

White plans to fianchetto the light-squared bishop. Black usually responds by mirroring White with 3...g6.
When contributing to this Wikibook, please follow the Conventions for organization.
# English Opening
### 1...c6

Planning to transpose into the Caro-Kann or Slav Defence. Note however that white can also reach the Reti opening by playing 2.Nf3

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
| 1.c4 c6 |
| | 2 |
| 1 | d4 | | See 1.d4 c6 2.c4 |
| 2 | e4 | | See 1.e4 c6 2.c4 |
| 3 | Nf3 | = |
| 4 | Nc3 | = |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
# English Opening - Symmetrical Variation
### 2. Nf3

Main line symmetrical. The idea in this variation is to achieve the pawn break on d4 for white. Black on the other hand might calmly accept the pawn exchange and develop comfortably, with the ideal of pinning and destroying the white knight on c3.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
| 2 | 3 | 4 | 5 |
| Nf3 Nf6 | d4 cxd4 | Nxd4 e6 | Nc3 Nc6 | = |
| ... g6 | Nc3 Bg7 | e3 Nf6 | d4 cxd4 | = |
| ... Nc6 | Nc3 Nf6 | += |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
# Symmetrical English - Wedberg Variation
### 5...e5

Named after Tom Wedberg, who developed and popularized in the 80's the idea of 5...e5 followed by Nge7.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 e5
| | 6 | 7 | 8 | 9 |
| 1 | O-O Nge7 | a3 O-O | Rb1 | | |
| 2 | a3 a5 | d4!? cxd4 | Nb5 d6 | e3 | |
| 3 | d3 Nge7 | Nd2 d6 | Nf1 | | (with the idea of Ne3) |
| 4 | Rb1 | | | | (Usually transpose to the other lines) |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Hansen, Carsten (2000). The Symmetrical English. Great Britain: Gambit. pp. 36–45. ISBN 1-901983-40-4.
* This Chess related article is a stub. Please assist Wikibooks by expanding it.
# Chess Opening Theory/1. c4/1...c5/2. Nf3/2...Nc6
### 2...Nc6

This continues the main line of the Symmetrical Variation.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation.
| 1.c4 c5 2.Nf3 Nc6 |
| | 3 | 4 | 5 |
| | Nc3 e5 | g3 g6 | Bg2 Bg7 | a3 Nge7 | = |
| | d4 cxd4 | Nxd4 Nf6 | Nc3 e6 | a3 Be7 | = |
| Three Knights Fianchetto | g3 g6 | Bg2 Bg7 | Nc3 d6 | O-O | = |
When contributing to this Wikibook, please follow the Conventions for organization.
# Chess Opening Theory/1. c4/1...c5/2. Nf3/2...Nc6/3. g3/3...g6/4. Bg2
### 4. Bg2

Black will continue to mirror White with 4...Bg7.
When contributing to this Wikibook, please follow the Conventions for organization.
# English Opening
## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
1.c4 c6 2.Nf3
| 2 | 3 | 4 |
| Nf3 d5 | g3 Nf6 | Bg2 Bg4 | = |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.
* This Chess related article is a stub. Please assist Wikibooks by expanding it.
# Communication Systems/Voltage-Controlled Oscillators
## Voltage Controlled Oscillators (VCO)

A voltage-controlled oscillator (VCO) is a device that outputs a sinusoid of a frequency that is a function of the input voltage. VCOs are not time-invariant, linear components. A complete study of how a VCO works will have to be relegated to a more detailed section based on feedback and oscillators. This page will, however, attempt to answer some of the basic questions about VCOs.
A basic VCO has input/output characteristics as such:
VCOs are often implemented using a special type of diode called a "Varactor". Varactors, when reverse-biased, produce a small amount of capacitance that varies with the input voltage.

## Phase-Locked Loops

If you are talking on your cellphone, and you are walking (or driving), the phase angle of your signal is going to change, as a function of your motion, at the receiver. This is a fact of nature, and is unavoidable. The solution to this then, is to create a device which can "find" a signal of a particular frequency, negate any phase changes in the signal, and output the clean wave, phase-change free. This device is called a Phase-Locked Loop (PLL), and can be implemented using a VCO.

## Purpose of VCO and PLL

VCO and PLL circuits are highly useful in modulating and demodulating systems. We will discuss the specifics of how VCO and PLL circuits are used in this manner in future chapters.

## Varactors

As a matter of purely professional interest, we will discuss varactors here.

## Further reading

* Clock and data recovery has detailed information about designing and analyzing PLLs.
# Communication Systems/Resources
## Wikibooks

* Communication Theory
* Voice over IP
* Internet Technologies
* Internet Engineering
* Analog and Digital Conversion
* Wireless Mesh Networks
* Data Coding Theory
* Communication Networks

## Wikipedia Articles

* Wikipedia:History Of Internet

## Books

* Garcia and Widjaja, Communication Networks: Fundamental Concepts and Key Architectures, Second Edition, McGraw Hill, 2004. ISBN 007246352X
* Stern and Mahmoud, Communication Systems: Analysis and Design, Prentice Hall, 2004. ISBN 0130402680
* Silage, Dennis, Digital Communication Systems Using SystemVue, DaVinci Engineering Press, 2006. ISBN 1584508507
* Haykin and Moher, Modern Wireless Communications, Prentice Hall, 2005. ISBN 0130224723
* Gibson, Jerry D. Principles of Digital and Analog Communications, Second Edition, Macmillan Publishing Company, 1989. ISBN 0023418605

## Online Tutorials

Fundamentals of Communication by Alcatel
# Communication Systems/Space-Division Multiplexing

This page is all about Space-Division Multiplexing (SDM).
# Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e5/3. dxe5/3...Ne4/4. a3

The move 4.a3 allows White to avoid the annoying bishop check on b4, the also annoying knight jump to b4, and prepares Qc2 to undermine Black's knight. Both Lalic and Nick de Firmian consider it to be White's best move, with de Firmian assessing it as leading to a large advantage for White. Black has several possible answers:
| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation.
1.d4 Nf6 2.c4 e5 3.dxe5 Ne4
| 4 | 5 | 6 | 7 | 8 |
| ... a5 | Nf3 Nc6 | Qc2 d5 | e3 Be6 | Be2 f6 | += |
| ... Qh4 | g3 Qh5 | Nf3 Nc6 | Qc2 Qf5 | Nbd2 Nxg3 | += |
| ... b6 | Nf3 Bb7 | Nbd2 Qe7 | Qc2 | | += |
| ... Nc6 | Nf3 d6 | Qc2 Bf5 | Nc3 Nxf2 | Qxf5 Nxh1 | += |
| ... ... | ... ... | ... d5 | e3 Bg4 | cxd5 Qxd5 | |
| ... d6 | Qc2 Nc5 | | | | |

## Footnotes

* ↑ Lalic calls it "undoubtedly the most critical line". Lalic 1998, p.132
* 1 2 3 de Firmian 2008, p.504
* ↑ Lalic 1998, p.134 Marinellei – Osmanbegovic, Cannes 1995
* ↑ Lalic 1998, p.134 Fronczek – Hoffmann, Chess Bundesliga 1996
* ↑ Lalic 1998, p.135 Olsen – Conquest, Reykjavik 1996
* 1 2 Lalic 1998, p.136
* ↑ Borik 1986, p.86
* ↑ "Wiegel – Fiebig, correspondence 1984". ChessGames.com.
* ↑ Lalic 1998, p.137 "Van Wely – Alburt, New York 1994". ChessGames.com.
* ↑ Moskalenko 2007, p.223
* ↑ Lalic 1998, p.133 "M.Roeder – Stefanova, Groningen 1997". ChessGames.com.
* ↑ Moskalenko 2007, p.222
* ↑ Moskalenko 2007, p.231
* ↑ Lalic 1998, p.139 "Timoschenko – Welling, Ostend 1991". ChessGames.com.
* ↑ Lalic 1998, p.139 Ricardi – Perez, Olivos 1993
* ↑ "Hillarp Persson – Romero Holmes, Hotel Bali Stars 2003". ChessGames.com.

## References

* Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.
* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
# Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e5/3. dxe5/3...Ng4
## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation.
1.d4 Nf6 2.c4 e5 3.dxe5 Ng4
| | 4 | 5 | 6 | 7 | 8 |
| Adler variation | Nf3 Bc5 | e3 Nc6 | Be2 O-O | O-O Re8 | Nc3 Ngxe5 | += |
| Rubinstein variation | Bf4 Nc6 | Nf3 Bb4+ | Nbd2 Qe7 | e3 Ngxe5 | Nxe5 Nxe5 | += |
| | ... ... | ... ... | Nc3 Bxc3+ | bxc3 Qe7 | Qd5 f6 | += |
| | ... g5 | Bg3 Bg7 | Nf3 Nc6 | Nc3 Ngxe5 | Nxe5 Nxe5 | += |
| Alekhine variation | e4 Nxe5 | f4 Nec6 | a3 a5 | Be3 Na6 | | = |
| | e3 Nxe5 | Nh3 d6+ | Nf4 g6 | Nc3 Bg7 | Be2 O-O | += |
# Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e5/3. dxe5/3...Ng4/4. Bf4

This is called the "Rubinstein variation" in reference to the famous game Rubinstein – Vidmar (Berlin 1918) where the move 4.Bf4 was first employed. The move 4.Bf4 first aims to be able to answer 4...Bc5 with 5.e3 without blocking the Bc1, contrary to what happens in the Adler line 4.Nf3. On the other hand, the early development of the bishop means that White is slightly exposed to a Bb4+.
Also, in the Adler line White faces the risk of a strong attack against his kingside, while in the 4.Bf4 variation this is seldom the case because White's Bf4 is well placed to protect White's kingside if needed. However, in some cases the Bf4 can become slightly exposed (e.g. some variations of the Rubinstein line when Black plays g7–g5 and h7–h5).
Apart from the sideline 4...g5, the main line continues with both camps developing their pieces around the e5-pawn with 4...Nc6 5.Nf3 Bb4+ (preparing 6...Qe7) when White has an important choice to make between the two moves 6.Nc3 and 6.Nbd2, each leading to extremely different play. With 6.Nc3 White accepts to have his pawn structure on the queenside ruined, in return for a material advantage of one pawn, the bishop pair and active play in the center.
On the other hand, with 6.Nbd2 White gives back the gambited pawn in order to keep a healthy pawn structure and to get the bishop pair. After 6...Qe7 White generally plays 7.a3 in order to force the immediate exchange of the Bb4 for the Nd2 and get the bishop pair, a space advantage and a minority attack on the queenside. White can also try 7.e3 which tries to win a tempo over the 7.a3 variation but may end up with the Bb4/Nd2 exchange made in less favorable circumstances, or not made at all. The maverick gambit 6...f6 or 6...d6 also exist.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation.
1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.Bf4
| 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| ... Nc6 | Nf3 Bb4+ | Nbd2 Qe7 | e3 Ngxe5 | Nxe5 Nxe5 | Be2 | | += |
| ... ... | ... ... | ... d6 | | | | | += |
| ... ... | ... ... | ... f6 | | | | | += |
| ... ... | ... ... | Nc3 Bxc3+ | bxc3 Qe7 | Qd5 f6 | | | += |
| ... g5 | Bg3 Bg7 | Nf3 Nc6 | Nc3 Ngxe5 | Nxe5 Nxe5 | e3 d6 | c5 | += |

## Footnotes

* ↑ Moskalenko 2007, p.15
* ↑ Tseitlin 1992, p.126 Rubinstein – Tartakower, Kissingen 1928

## References

* Borik, Otto (1986). Budapest Gambit. The Macmillan Chess Library. ISBN 978-0020175001.
* Lalić, Bogdan (1998). The Budapest Gambit. Batsford. ISBN 9780713484564.
* Moskalenko, Viktor (2007). The Fabulous Budapest Gambit. New In Chess. ISBN 978-90-5691-224-6.
* Tseitlin, Mikhail (1992). The Budapest for the Tournament Player. Batsford. ISBN 978-0805024319. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
# Danzig

The stamps of Danzig are now listed within Poland. See Poland, sub-group GO-B.