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Inorganic Chemistry/Chemical Bonding/Orbital hybridization

In chemistry, hybridisation (or hybridization) is the concept of mixing atomic orbitals into new hybrid orbitals suitable for the pairing of electrons to form chemical bonds in valence bond theory. Hybrid orbitals are very useful in the explanation of molecular geometry and atomic bonding properties.

History and uses
Chemist Linus Pauling first developed hybridisation theory in order to explain the structure of molecules such as methane (CH4). Pauling pointed out that a carbon atom forms four bonds by using one s and three p orbitals, so that "it might be inferred" that a carbon atom would form three bonds at right angles (using p orbitals) and a fourth weaker bond using the s orbital in some arbitrary direction. In reality however, methane has four bonds of equivalent strength separated by the tetrahedral bond angle of 109.5°. Pauling explained this by supposing that in the presence of four hydrogen atoms, the s and p orbitals form four equivalent combinations or hybrid orbitals, each denoted by sp3 to indicate its composition, which are directed along the four C-H bonds. Historically, this concept was developed for such simple chemical systems but the approach was later applied more widely, and today it is considered an effective heuristic for rationalizing the structures of organic compounds. It gives a simple orbital picture equivalent to Lewis structures. Hybridisation theory finds its use mainly in organic chemistry.

Hybridisation theory is an integral part of organic chemistry. For drawing reaction mechanisms sometimes a classical bonding picture is needed with two atoms sharing two electrons. Hybridisation theory explains bonding in alkenes and methane. The amount of p character or s character, which is decided mainly by orbital hybridisation, can be used to reliably predict molecular properties such as acidity or basicity.

Overview
Orbitals are a model representation of the behavior of electrons within molecules. In the case of simple hybridisation, this approximation is based on atomic orbitals, similar to those obtained for the hydrogen atom, the only atom for which an exact analytic solution to its Schrödinger equation is known. In heavier atoms, like carbon, nitrogen, and oxygen, the atomic orbitals used are the 2s and 2p orbitals, similar to excited state orbitals for hydrogen.

Hybrid orbitals are assumed to be mixtures of atomic orbitals, superimposed on each other in various proportions. For example, in methane, the C hybrid orbital which forms each C-H bond consists of 25% s character and 75% p character and is thus described as sp3 (read as s-p-three) hybridised. Quantum mechanics describes this hybrid as an sp3 wavefunction of the form N[s + (√3)pσ], where N is a normalization constant (here 1/2) and pσ is a p orbital directed along the C-H axis to form a sigma bond. The p-to-s ratio (denoted λ in general) is √3 in this example, and N2λ2 = 3/4 is the p character or the weight of the p component.

In general, any two hybrid orbitals on the same atom must be mutually orthogonal. For an atom with s and p orbitals forming hybrids hi and hj with included angle $$\theta$$, the orthogonality condition implies the relation: 1 + $$\lambda$$i$$\lambda$$j cos($$\theta$$) = 0. The p-to-s ratio for hybrid i is $$\lambda$$i2, and for hybrid j it is $$\lambda$$j2. The bond directed towards a more electronegative substituent tends to have higher p-character as stated in Bent's rule. In the special case of equivalent hybrids on the same atom, again with included angle $$\theta$$, the equation reduces to just 1 + $$\lambda$$2 cos($$\theta$$) = 0. For example, BH3 has a trigonal planar geometry, three 120° bond angles, three equivalent hybrids about the boron atom, and thus 1 + $$\lambda$$2 cos($$\theta$$) = 0 becomes 1 + $$\lambda$$2 cos(120°) = 0, giving $$\lambda$$2 = 2 for the p-to-s ratio. In other words, sp2 hybrids.

sp3
For a tetrahedrally coordinated carbon (e.g., methane CH4), the carbon should have 4 orbitals with the correct symmetry to bond to the 4 hydrogen atoms.

Carbon's ground state configuration is 1s2 2s2 2p2 or more easily read:

(Note: The 1s orbital is lower in energy than the 2s orbital, and the 2s orbital is lower in energy than the 2p orbitals)

The carbon atom can utilize its two singly occupied p-type orbitals, to form two covalent bonds with two hydrogen atoms, yielding the singlet methylene CH2, the simplest of the carbenes. The carbon atom can also bond to four hydrogen atoms by an excitation of an electron from the doubly occupied 2s orbital to the empty 2p orbital, so that there are four singly occupied orbitals.

The energy released by formation of two additional bonds more than compensates for the excitation energy required, energetically favouring the formation of four C-H bonds.

Quantum mechanically, the lowest energy is obtained if the four bonds are equivalent, which requires that they be formed from equivalent orbitals on the carbon. A set of four equivalent orbitals can be obtained that are linear combinations of the valence-shell (core orbitals are almost never involved in bonding) s and p wave functions, which are the four sp3 hybrids.

In CH4, four sp3 hybrid orbitals are overlapped by hydrogen's 1s orbital, yielding four σ (sigma) bonds (that is, four single covalent bonds) of the same length and strength.

translates into

sp2
Other carbon based compounds and other molecules may be explained in a similar way as methane. For example, ethene (C2H4) has a double bond between the carbons. The Lewis structure looks like this:

For this molecule, carbon sp2 hybridises, because one π (pi) bond is required for the double bond between the carbons and only three σ bonds are formed per carbon atom. In sp2 hybridisation the 2s orbital is mixed with only two of the three available 2p orbitals:

forming a total of three sp2 orbitals and one remaining p orbital. In ethylene the two carbon atoms form a σ bond by overlapping two sp2 orbitals and each carbon atom forms two covalent bonds with hydrogen by s–sp2 overlap all with 120° angles. The π bond between the carbon atoms perpendicular to the molecular plane is formed by 2p–2p overlap. The hydrogen-carbon bonds are all of equal strength and length, which agrees with experimental data.

sp
The chemical bonding in compounds such as alkynes with triple bonds is explained by sp hybridization. In this model, the 2s orbital mixes with only one of the three p-orbitals,

resulting in two sp orbitals and two remaining p orbitals. The chemical bonding in acetylene (C2H2) consists of sp–sp overlap between the two carbon atoms forming a σ bond and two additional π bonds formed by p–p overlap. Each carbon also bonds to hydrogen in a sigma s–sp overlap at 180° angles.

Hybridisation and molecule shape
Hybridisation helps to explain molecule shape, since the angles between bonds are (approximately) equal to the angles between hybrid orbitals.

spx hybridisation
As the valence orbitals of main group elements are the one s and three p orbitals with the corresponding octet rule, spx hybridisation is used to model the shape of these molecules.

spxdy hybridisation
As the valence orbitals of transition metals are the five d, one s and three p orbitals with the corresponding 18-electron rule, spxdy hybridisation is used to model the shape of these molecules. These molecules tend to have multiple shapes corresponding to the same hybridisation due to the different d-orbitals involved. As the p-orbitals are not necessarily fully occupied, the square planar shape has 16 valence electrons.

sdx hybridisation
In certain transition metal complexes with a low d electron count, the p-orbitals are unoccupied and sdx hybridisation is used to model the shape of these molecules.

Octet expansion
In some general chemistry textbooks, hybridisation is presented for main group AX5 and above using an "expanded octet" scheme with d-orbitals first proposed by Pauling. However, such a scheme is now considered to be incorrect in light of computational chemistry calculations.

In 1990, Magnusson published a seminal work definitively excluding the role of d-orbital hybridization in bonding in hypervalent compounds of second-row elements. This had long been a point of contention and confusion in describing these molecules using molecular orbital theory. Part of the confusion here originates from the fact that one must include d-functions in the basis sets used to describe these compounds (or else unreasonably high energies and distorted geometries result), and the contribution of the d-function to the molecular wavefunction is large. These facts were historically interpreted to mean that d-orbitals must be involved in bonding. However, Magnusson concludes in his work that d-orbital involvement is not implicated in hypervalency.

Resonance
In light of computational chemistry, a better treatment would be to invoke sigma bond resonance in addition to hybridisation, which implies that each resonance structure has its own hybridisation scheme. All resonance structures must obey the octet rule.

Hybridisation in computational VB theory
While the simple model of orbital hybridisation is commonly used to explain molecular shape, hybridisation is used differently when computed in modern valence bond programs. Specifically, hybridisation is not determined a priori but is instead variationally optimized to find the lowest energy solution and then reported. This means that all artificial constraints, specifically two constraints, on orbital hybridisation are lifted: This means that in practice, hybrid orbitals do not conform to the simple ideas commonly taught and thus in scientific computational papers are simply referred to as spx, spxdy or sdx hybrids to express their nature instead of more specific integer values.
 * that hybridisation is restricted to integer values (isovalent hybridisation)
 * that hybrid orbitals are orthogonal to one another (hybridisation defects)

Isovalent hybridisation
Although ideal hybrid orbitals can be useful, in reality most bonds require orbitals of intermediate character, analogous to intermediate ionic-covalent character. This requires an extension to include flexible weightings of atomic orbitals of each type (s, p, d) and allows for a quantitative depiction of bond formation when the molecular geometry deviates from ideal bond angles. The amount of p-character is not restricted to integer values; i.e., hybridisations like sp2.5 are also readily described.

The hybridisation of bond orbitals is determined by Bent's rule: "Atomic s character concentrates in orbitals directed toward electropositive substituents".

For molecules with lone pairs, the bonding orbitals are isovalent spx hybrids. For example, the two bond-forming hybrid orbitals of oxygen in water can be described as sp4.0 to give the interorbital angle of 104.5°. This means that they have 20% s character and 80% p character and does not imply that a hybrid orbital is formed from one s and four p orbitals on oxygen since the 2p subshell of oxygen only contains three p orbitals.

Hybridization defects
Hybridisation of s and p orbitals to form effective spx hybrids requires that they have comparable radial extent. While 2p orbitals are on average less than 10% larger than 2s, in part attributable to the lack of a radial node in 2p orbitals, 3p orbitals which have one radial node, exceed the 3s orbitals by 20–33%. The difference in extent of s and p orbitals increases further down a group. The hybridisation of atoms in chemical bonds can be analysed by considering localised molecular orbitals, for example using natural localised molecular orbitals in a natural bond orbital (NBO) scheme. In methane, CH4, the calculated p/s ratio is approximately 3 consistent with "ideal" sp3 hybridisation, whereas for silane, SiH4, the p/s ratio is closer to 2. A similar trend is seen for the other 2p elements. Substitution of fluorine for hydrogen further decreases the p/s ratio. The 2p elements exhibit near ideal hybridisation with orthogonal hybrid orbitals. For heavier p block elements this assumption of orthogonality cannot be justified. These deviations from the ideal hybridisation were termed hybridisation defects by Kutzelnigg.

However, computational VB groups such as Gerratt, Cooper and Raimondi (SCVB) as well as Shaik and Hiberty (VBSCF) go a step further to argue that even for model molecules such as methane, ethylene and acetylene, the hybrid orbitals are already defective and nonorthogonal, with hybridisations such as sp1.76 instead of sp3 for methane.

Photoelectron spectra
One misconception concerning orbital hybridisation is that it incorrectly predicts the ultraviolet photoelectron spectra of many molecules. While this is true if Koopmans' theorem is applied to localized hybrids, quantum mechanics requires that the (in this case ionized) wavefunction obey the symmetry of the molecule which implies resonance in valence bond theory. For example, in methane, the ionized states (CH4+) can be constructed out of four resonance structures attributing the ejected electron to each of the four sp3 orbitals. A linear combination of these four structures, conserving the number of structures, leads to a triply degenerate T2 state and a A1 state. The difference in energy between the ionized state and the ground state would be the ionization energy, which yields two values in agreement with experiment.

Localized MOs vs canonical MOs
Bonding orbitals formed from hybrid atomic orbitals may be considered as localized molecular orbitals, which can be formed from the delocalised orbitals of molecular orbital theory by an appropriate mathematical transformation. For molecules in the ground state, this transformation of the orbitals leaves the total many-electron wave function unchanged. The hybrid orbital description of the ground state is therefore equivalent to the delocalised orbital description for ground state total energy and electron density, as well as the molecular geometry that corresponds to the minimum total energy value.

Two localized representations
Molecules with multiple bonds or multiple lone pairs can have orbitals represented in terms of sigma and pi symmetry or equivalent orbitals. Different valence bond methods use either of the two representations, which have mathematically equivalent total many-electron wave functions and are related by a unitary transformation of the set of occupied molecular orbitals.

For multiple bonds, the sigma-pi representation is the predominant one compared to the equivalent orbital (bent bond) representation. In contrast, for multiple lone pairs, most textbooks use the equivalent orbital representation. However, the sigma-pi representation is also used, such as by Weinhold and Landis within the context of natural bond orbitals, a localized orbital theory containing modernized analogs of classical (valence bond/Lewis structure) bonding pairs and lone pairs. For the hydrogen fluoride molecule, for example, two F lone pairs are essentially unhybridized p orbitals, while the other is an spx hydrid orbital. An analogous consideration applies to water (one O lone pair is in a pure p orbital, another is in an spx hybrid orbital).


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Inorganic Chemistry/Chemical Bonding/VSEPR theory

Valence shell electron pair repulsion (VSEPR) theory is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Nyholm.

The premise of VSEPR is that the valence electron pairs surrounding an atom tend to repel each other and will, therefore, adopt an arrangement that minimizes this repulsion. This in turn decreases the molecule's energy and increases its stability, which determines the molecular geometry.

History
The idea of a correlation between molecular geometry and number of valence electrons (both shared and unshared) was first presented in a Bakerian Lecture in 1940 by Nevil Sidgwick and Herbert Powell at the University of Oxford. In 1957 Ronald Gillespie and Ronald Sydney Nyholm at University College London refined this concept to build a more detailed theory capable of choosing between various alternative geometries.

Overview
VSEPR theory is used to predict the arrangement of electron pairs around central atoms in molecules, especially simple and symmetric molecules. A central atom is defined in this theory as an atom which is bonded to two or more other atoms, while a terminal atom is bonded to only one other atom. For example in the molecule methyl isocyanate (H3C-N=C=O), the two carbons and one nitrogen are central atoms, and the three hydrogens and one oxygen are terminal atoms. The geometry of the central atoms and their non-bonding electron pairs in turn determine the geometry of the larger whole molecule.

The number of electron pairs in the valence shell of a central atom is determined after drawing the Lewis structure of the molecule, and expanding it to show all bonding groups and lone pairs of electrons. In VSEPR theory, a double bond or triple bond is treated as a single bonding group. The sum of the number of atoms bonded to a central atom and the number of lone pairs formed by its nonbonding valence electrons is known as the central atom's steric number.

The electron pairs (or groups if multiple bonds are present) are assumed to lie on the surface of a sphere centered on the central atom and tend to occupy positions that minimize their mutual repulsions by maximizing the distance between them. The number of electron pairs (or groups), therefore, determines the overall geometry that they will adopt. For example, when there are two electron pairs surrounding the central atom, their mutual repulsion is minimal when they lie at opposite poles of the sphere. Therefore, the central atom is predicted to adopt a linear geometry. If there are 3 electron pairs surrounding the central atom, their repulsion is minimized by placing them at the vertices of an equilateral triangle centered on the atom. Therefore, the predicted geometry is trigonal. Likewise, for 4 electron pairs, the optimal arrangement is tetrahedral.

As a tool in predicting the geometry adopted with a given number of electron pairs, an often used physical demonstration of the principle of minimal electron pair repulsion utilizes inflated balloons. Through handling, balloons acquire a slight surface electrostatic charge that results in the adoption of roughly the same geometries when they are tied together at their stems as the corresponding number of electron pairs. For example, five balloons tied together adopt the trigonal bipyramidal geometry, just as do the five bonding pairs of a PCl5 molecule.

Steric number
The steric number of a central atom in a molecule is the number of atoms bonded to that central atom, called its coordination number, plus the number of lone pairs of valence electrons on the central atom. In the molecule SF4, for example, the central sulfur atom has four ligands; the coordination number of sulfur is four. In addition to the four ligands, sulfur also has one lone pair in this molecule. Thus, the steric number is 4 + 1 = 5.

Degree of repulsion
The overall geometry is further refined by distinguishing between bonding and nonbonding electron pairs. The bonding electron pair shared in a sigma bond with an adjacent atom lies further from the central atom than a nonbonding (lone) pair of that atom, which is held close to its positively charged nucleus. VSEPR theory therefore views repulsion by the lone pair to be greater than the repulsion by a bonding pair. As such, when a molecule has 2 interactions with different degrees of repulsion, VSEPR theory predicts the structure where lone pairs occupy positions that allow them to experience less repulsion. Lone pair–lone pair (lp–lp) repulsions are considered stronger than lone pair–bonding pair (lp–bp) repulsions, which in turn are considered stronger than bonding pair–bonding pair (bp–bp) repulsions, distinctions that then guide decisions about overall geometry when 2 or more non-equivalent positions are possible. For instance, when 5 valence electron pairs surround a central atom, they adopt a trigonal bipyramidal molecular geometry with two collinear axial positions and three equatorial positions. An electron pair in an axial position has three close equatorial neighbors only 90° away and a fourth much farther at 180°, while an equatorial electron pair has only two adjacent pairs at 90° and two at 120°. The repulsion from the close neighbors at 90° is more important, so that the axial positions experience more repulsion than the equatorial positions; hence, when there are lone pairs, they tend to occupy equatorial positions as shown in the diagrams of the next section for steric number five.

The difference between lone pairs and bonding pairs may also be used to rationalize deviations from idealized geometries. For example, the H2O molecule has four electron pairs in its valence shell: two lone pairs and two bond pairs. The four electron pairs are spread so as to point roughly towards the apices of a tetrahedron. However, the bond angle between the two O–H bonds is only 104.5°, rather than the 109.5° of a regular tetrahedron, because the two lone pairs (whose density or probability envelopes lie closer to the oxygen nucleus) exert a greater mutual repulsion than the two bond pairs.

A bond of higher bond order also exerts greater repulsion since the pi bond electrons contribute. For example in isobutylene, (H3C)2C=CH2, the H3C−C=C angle (124°) is larger than the H3C−C−CH3 angle (111.5°). However, in the carbonate ion,, all three C−O bonds are equivalent with angles of 120° due to resonance.

AXE method
The "AXE method" of electron counting is commonly used when applying the VSEPR theory. The electron pairs around a central atom are represented by a formula AXnEm, where A represents the central atom and always has an implied subscript one. Each X represents a ligand (an atom bonded to A). Each E represents a lone pair of electrons on the central atom. The total number of X and E is known as the steric number. For example in a molecule AX3E2, the atom A has a steric number of 5.

When the substituent (X) atoms are not all the same, the geometry is still approximately valid, but the bond angles may be slightly different from the ones where all the outside atoms are the same. For example, the double-bond carbons in alkenes like C2H4 are AX3E0, but the bond angles are not all exactly 120°. Likewise, SOCl2 is AX3E1, but because the X substituents are not identical, the X–A–X angles are not all equal.

Based on the steric number and distribution of Xs and Es, VSEPR theory makes the predictions in the following tables.

Main-group elements
For main-group elements, there are stereochemically active lone pairs E whose number can vary between 0 to 3. Note that the geometries are named according to the atomic positions only and not the electron arrangement. For example, the description of AX2E1 as a bent molecule means that the three atoms AX2 are not in one straight line, although the lone pair helps to determine the geometry.

Transition metals (Kepert model)
The lone pairs on transition metal atoms are usually stereochemically inactive, meaning that their presence does not change the molecular geometry. For example, the hexaaquo complexes M(H2O)6 are all octahedral for M = V3+, Mn3+, Co3+, Ni2+ and Zn2+, despite the fact that the electronic configurations of the central metal ion are d2, d4, d6, d8 and d10 respectively. The Kepert model ignores all lone pairs on transition metal atoms, so that the geometry around all such atoms corresponds to the VSEPR geometry for AXn with 0 lone pairs E. This is often written MLn, where M = metal and L = ligand. The Kepert model predicts the following geometries for coordination numbers of 2 through 9:

Examples
The methane molecule (CH4) is tetrahedral because there are four pairs of electrons. The four hydrogen atoms are positioned at the vertices of a tetrahedron, and the bond angle is cos−1(−$1/3$) ≈ 109° 28′. This is referred to as an AX4 type of molecule. As mentioned above, A represents the central atom and X represents an outer atom.

The ammonia molecule (NH3) has three pairs of electrons involved in bonding, but there is a lone pair of electrons on the nitrogen atom. It is not bonded with another atom; however, it influences the overall shape through repulsions. As in methane above, there are four regions of electron density. Therefore, the overall orientation of the regions of electron density is tetrahedral. On the other hand, there are only three outer atoms. This is referred to as an AX3E type molecule because the lone pair is represented by an E. By definition, the molecular shape or geometry describes the geometric arrangement of the atomic nuclei only, which is trigonal-pyramidal for NH3.

Steric numbers of 7 or greater are possible, but are less common. The steric number of 7 occurs in iodine heptafluoride (IF7); the base geometry for a steric number of 7 is pentagonal bipyramidal. The most common geometry for a steric number of 8 is a square antiprismatic geometry. Examples of this include the octacyanomolybdate and octafluorozirconate  anions. The nonahydridorhenate ion in potassium nonahydridorhenate is a rare example of a compound with a steric number of 9, which has a tricapped trigonal prismatic geometry.

Possible geometries for steric numbers of 10, 11, 12, or 14 are bicapped square antiprismatic (or bicapped dodecadeltahedral), octadecahedral, icosahedral, and bicapped hexagonal antiprismatic, respectively. No compounds with steric numbers this high involving monodentate ligands exist, and those involving multidentate ligands can often be analysed more simply as complexes with lower steric numbers when some multidentate ligands are treated as a unit.

Exceptions
There are groups of compounds where VSEPR fails to predict the correct geometry.

Some AX2E0 molecules
The shapes of heavier Group 14 element alkyne analogues (RM≡MR, where M = Si, Ge, Sn or Pb) have been computed to be bent.

Some AX2E2 molecules
One example is molecular lithium oxide, Li2O, which is linear rather than being bent, and this has been ascribed to the bonding's being in essence ionic, leading to strong repulsion between the lithium atoms.

Another example is O(SiH3)2 with an Si-O-Si angle of 144.1°, which compares to the angles in Cl2O (110.9°), (CH3)2O (111.7°)and N(CH3)3 (110.9°). Gillespie's rationalisation is that the localisation of the lone pairs, and therefore their ability to repel other electron pairs, is greatest when the ligand has an electronegativity similar to, or greater than, that of the central atom. When the central atom is more electronegative, as in O(SiH3)2, the lone pairs are less well-localised and have a weaker repulsive effect. This fact, combined with the stronger ligand-ligand repulsion (-SiH3 is a relatively large ligand compared to the examples above), gives the larger-than-expected Si-O-Si bond angle.

Some AX6E1 and AX8E1 molecules
Some AX6E1 molecules, e.g. xenon hexafluoride (XeF6) and the Te(IV) and Bi(III) anions,, , , and , are octahedra rather than pentagonal pyramids, and the lone pair does not affect the geometry to the degree predicted by VSEPR. One rationalization is that steric crowding of the ligands allows no room for the non-bonding lone pair; another rationalization is the inert pair effect. Similarly, the octafluoroxenate ion in nitrosonium octafluoroxenate(VI)  is a square antiprism and not a bicapped trigonal prism (as predicted by VSEPR theory for an AX8E1 molecule), despite having a lone pair.

Square planar ML4 complexes
The Kepert model predicts that ML4 transition metal molecules are tetrahedral in shape, and it cannot explain the formation of square planar complexes. The majority of such complexes exhibit a d8 configuration as for the tetrachloroplatinate ion. The explanation of the shape of square planar complexes involves electronic effects and requires the use of crystal field theory.

Complexes with strong d-contribution
Some transition metal complexes with low d electron count have unusual geometries, which can be ascribed to d subshell bonding interaction. Gillespie found that this interaction produces bonding pairs that also occupy the respective antipodal points (ligand opposed) of the sphere. This phenomenon is an electronic effect resulting from the bilobed shape of the underlying sdx hybrid orbitals. The repulsion of these bonding pairs leads to a different set of shapes.

The gas phase structures of the triatomic halides of the heavier members of group 2, (i.e., calcium, strontium and barium halides, MX2), are not linear as predicted but are bent, (approximate X–M–X angles: CaF2, 145°; SrF2, 120°; BaF2, 108°; SrCl2, 130°; BaCl2, 115°; BaBr2, 115°; BaI2, 105°). It has been proposed by Gillespie that this is also caused by bonding interaction of the ligands with the d subshell of the metal atom, thus influencing the molecular geometry.

Odd-electron molecules
The VSEPR theory can be extended to molecules with an odd number of electrons by treating the unpaired electron as a "half electron pair". In effect, the odd electron has an influence on the geometry which is similar to a full electron pair, but less pronounced so that the geometry may be intermediate between the molecule with a full electron pair and the molecule with one less electron pair on the central atom.

For example, nitrogen dioxide (NO2) is an AX2E0.5 molecule, with an unpaired electron on the central nitrogen. VSEPR predicts a geometry similar to the ion (AX2E1, bent, bond angle approx. 120°) but intermediate between  and  (AX2E0, linear, 180°). In fact NO2 is bent with an angle of 134° which is closer to 120° than to 180°, in qualitative agreement with the theory.

Similarly chlorine dioxide (ClO2, AX2E1.5) has a geometry similar to but intermediate between  and.

Finally the methyl radical (CH3) is predicted to be trigonal pyramidal like the methyl anion but with a larger bond angle as in the trigonal planar methyl cation. However in this case the VSEPR prediction is not quite true as CH3 is actually planar, although its distortion to a pyramidal geometry requires very little energy.

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


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User talk:Complex

Welcome!
Welcome, Complex!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally.-- – Mike.lifeguard  | talk 20:30, 25 March 2008 (UTC)

title: User talk:Complex


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User talk:Octobox

Welcome, Octobox!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 20:32, 25 March 2008 (UTC)

Original Research
Please note that Wikibooks doesn't allow OR (though it's defined slightly differently here than at the English Wikipedia. Your additions to Lucid Dreaming look like they might require sourcing. Please take care to provide references to avoid stating opinions. Thanks – Mike.lifeguard  | talk 20:32, 25 March 2008 (UTC)

title: User talk:Octobox


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User talk:Katana0182

Welcome, Katana0182!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Νεοπτόλεμος ( talk | email | contribs ) 20:53, 25 March 2008 (UTC)

title: User talk:Katana0182


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User:MeekMark

See my Wikipedia home page

title: User:MeekMark


text: User talk:68.98.69.59

title: User talk:68.98.69.59


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Talk:Blender 3D: Noob to Pro/Making exe

I deleted the second sentence declaring that "..this is actually a very easy process." It is a self-congratulation and provides no content. I wish I had a euro for every time I saw it.

How doyou change the icon??

There is a program called "icon replacer" specificly for blender- u can find it at http://blenderartists.org/forum/showthread.php?t=108258

you welcome!

Thanks. But it always uses up 100% of my CPU (its a single core) even when its just sitting there doing nothing. Is there any way to fix that? -203.188.235.9 (talk) 15:06, 23 May 2008 (UTC)

Noob: when I try to save my file, blender crashes. What am I doing wrong?

where do you get the VCOMP90.DLL and dose it help the game graphics if not why dose the cmd prompt thingy you get with blender game says shaders not supported.

Hey, when I hit 'Save as runtime' it says it can't make runtime because it can't find runtime. I'm running on Mac leopard. ~Eeko

On my Windows 7 Home Premium 64bit: When I try to run the game .exe there is an error message "wrap_oal.exe missing". Seems to not be only on my computer, I found others with same problem too (http://www.google.com/search?q=blender+wrap_oal.dll). Maybe we should include this file in the list of files you should copy from the Blender folder?

title: Talk:Blender 3D: Noob to Pro/Making exe


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Muggles' Guide to Harry Potter/Magic/Clabbert

Overview
Clabberts are agile, tree-dwelling creatures.

Extended Description
The Clabbert's long, supple limbs make them ideal for swinging between branches, which likens them to some primates. Their hands and feet are webbed, and their smooth, hairless skin is mottled green, giving them an amphibious appearance. They bear two short horns and have wide, grinning mouths full of sharp teeth. Clabberts are easily distinguished by the large pustule in the center of their foreheads, which turns red and flashes at approaching danger, including Muggles. The International Confederation of Wizards fines those who keep Clabberts within the sight of Muggles; they cause too much unwanted attention (by appearing to have their 'Christmas lights' up in mid-summer).

The Clabbert originated in southern USA, but is exported worldwide. Their diet consists of small lizards and birds.


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Muggles' Guide to Harry Potter/Magic/Crup

Extended Description
Mentioned only in passing in Harry Potter and the Order of the Phoenix: Professor Grubbly-Plank, in response to a question from Professor Umbridge, says that she will be training the class to recognize Knarls and Crups.


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Muggles' Guide to Harry Potter/Magic/Dugbog

Extended Description
The Dugbog is never described in the principle books. The only mention is in Harry Potter and the Half-Blood Prince, when Ron's essay on Dementors is rendered an essay on Dugbogs by a failure of a spell-checking quill Ron had bought from Fred and George.


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Muggles' Guide to Harry Potter/Magic/Erkling

Analysis
The Erkling is an elfish creature, which has a particular affinity for the taste of children. Its high pitched cackle is entrancing to children, and it uses this to lure them away from their guardians to eat them. However, strict control by the German Ministry of Magic has greatly reduced the number of Erkling attacks. The last known Erkling attack was on a six-year-old called Bruno Schmidt. The Erkling in question was killed when Schmidt hit it over the head with his father's collapsible cauldron. These creatures also enjoy shooting darts at unsuspecting victims.

Etymology
The name Erkling may have come from the English word irk, meaning to annoy. It also might be a variant of "erlking," an elfish creature in German mythology which has a fatal influence on children. The Erlking is featured prominently in "Der Erlkönig," a poem by Johann Wolfgang Goethe which was set to music by many composers, most notably Franz Schubert. Erlkönig literally means Alder King.


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Muggles' Guide to Harry Potter/Magic/Fire Crab

Overview
Fire Crabs appear only once in the books, in Harry Potter and the Goblet of Fire, and then only in passing. They are not described in the principal books and play no real role in the story.

Extended Description
Fire Crabs are mentioned only in passing in Harry Potter and the Goblet of Fire, where a story written about Hagrid by Rita Skeeter suggested that the Blast-Ended Skrewts that he was raising looked to be unauthorized cross-breeds between Fire Crabs and Manticores.

From Fantastic Beasts and Where to Find Them, we learn that fire crabs are commonly mistaken for turtles with jewel-encrusted shells. Fire crab shells can also be used as cauldrons.


text:
Muggles' Guide to Harry Potter/Magic/Glumbumble

Extended Description
A furry insect.


text: Muggles' Guide to Harry Potter/Magic/Graphorn


text:
C++ Programming/Code/Standard C Library/Functions/strlen

strlen
The strlen function returns the length of str (determined by the number of characters before null termination).

 * Related topics: memcpy - strchr - strcmp - strncmp


text:
User talk:12.207.130.44

Join Us!
-- – Mike.lifeguard  | talk 00:41, 26 March 2008 (UTC)

title: User talk:12.207.130.44


text:
C++ Programming/Code/Standard C Library/Functions/strncpy

strncpy
The strncpy function copies at most count characters of from to the string to. Only if from has less than count characters, is the remainder padded with '\0' characters. The return value is the resulting string.

 * Related topics: memcpy - strchr - strcpy - strncat - strncmp


text:
C++ Programming/Code/Standard C Library/Functions/strncat

strncat
The function strncat concatenates at most count characters of str2 onto str1, adding a null termination. The resulting string is returned.

 * Related topics: strcat - strchr - strncmp - strncpy


title: User:Imzadi1979


text:
User talk:203.81.188.42

Join Us!
-- – Mike.lifeguard  | talk 01:14, 26 March 2008 (UTC)

title: User talk:203.81.188.42


text:
Category:Useful Wikibooks pages

These pages probably describe how things are done at Wikibooks, but are not policy. If the need arises, these pages may become policy proposals, and though a process by which a proposal gains consensus, a proposal may become policy.

title: Category:Useful Wikibooks pages


text:
Indian Tipi

The tipi was durable, provided warmth and comfort in winter, was dry during heavy rains, and was cool in the heat of summer. Tipis could be disassembled and packed away quickly when a tribe decided to move, and could be reconstructed quickly when the tribe settled in a new area. This portability is important to those who have a nomadic lifestyle.

Contents

 * /Title Page/
 * /Tipi History/
 * /Sioux Tipi/
 * /Sioux Tipi Pattern/
 * /Smoke Flaps/
 * /Erecting the Sioux Tipi/
 * /Eighteen Pole Tipi/
 * /Sioux Tipi Parts/
 * /Tipi Doors/
 * /Tipi Lining and Ozan/
 * /Sioux Buffalo Hide Tipi/
 * /Simple Tipi Design/
 * /Modern Tipi Design/
 * /Unusual Tipi Design/
 * /Pole Rack/
 * /Camp Circles/

title: Indian Tipi


text:
Talk:Adventist Youth Honors Answer Book/Household Arts/Cooking - Advanced

Edit history of the Ratatouille recipe

 * 12:15, 26 February 2008 66.249.90.136 (Talk | block) (2,065 bytes) (→Directions) (rollback | undo)
 * 19:26, 26 July 2007 67.49.8.228 (Talk | block) (2,067 bytes) (undo)
 * 14:13, 22 July 2007 128.12.159.143 (Talk | block) (2,060 bytes) (→Directions) (undo)
 * 12:35, 2 July 2007 71.205.100.59 (Talk | block) (2,061 bytes) (undo)
 * 09:17, 30 October 2006 Herbythyme (Talk | contribs | block) m (alpha cats) (undo)
 * 22:08, 5 October 2005 Nmontague (Talk | contribs | block) m (undo)
 * 02:14, 28 July 2005 Kellen (Talk | contribs | block) (categories) (undo)
 * 05:42, 16 June 2005 Redlentil (Talk | contribs | block) (caps and links) (undo)
 * 15:30, 11 November 2004 Liblamb (Talk | contribs | block) m (undo)
 * 15:19, 11 November 2004 Liblamb (Talk | contribs | block) m (category) (undo)
 * 19:39, 25 February 2004 Gentgeen (Talk | contribs | block) (header) (undo)
 * 19:37, 25 February 2004 Gentgeen (Talk | contribs | block) (wikified) (undo)
 * 17:15, 23 February 2004 82.33.96.38 (Talk | block) (Many edits (to the English, not factual changes)) (undo)
 * 08:44, 23 February 2004 Dysprosia (Talk | contribs | block) (move talk to talk) (undo)
 * 05:17, 23 February 2004 Karen Johnson (Talk | contribs | block)

Edit history of the Green bean casserole recipe

 * 14:51, 23 December 2006 Bob2 (Talk | contribs | block) (rollback | undo)
 * 14:45, 23 December 2006 Bob2 (Talk | contribs | block) (New page: {{recipesummary|Casserole

Edit history for Curried Rice recipe
* (cur) (last) 01:01, 31 July 2007 Webaware (Talk | contribs | block) m (1,007 bytes) (Revert to revision 511227 dated 2006-07-03 17:29:15 by Ants Go Marching using popups) (rollback | undo) * (cur) (last) 00:09, 31 July 2007 Crazyperson511 (Talk | contribs | block) (1,042 bytes) (→Procedure) (undo) * (cur) (last) 00:07, 31 July 2007 Crazyperson511 (Talk | contribs | block) m (1,023 bytes) (→Ingredients) (undo) * (cur) (last) 13:29, 3 July 2006 Ants Go Marching (Talk | contribs | block) m (undo) * (cur) (last) 19:07, 21 June 2006 Ace of Sevens (Talk | contribs | block) (added a few clarifications to the recipe.) (undo) * (cur) (last) 22:43, 23 May 2006 Ace of Sevens (Talk | contribs | block) (removed cardigan vandalism) (undo) * (cur) (last) 15:47, 20 May 2006 203.59.161.5 (Talk | block) (supplemented recipe with cardigan) (undo) * (cur) (last) 14:20, 6 October 2005 205.174.48.56 (Talk | block) (→Procedure) (undo) * (cur) (last) 03:51, 24 July 2005 Kellen (Talk | contribs | block) (template) (undo) * (cur) (last) 08:00, 11 November 2004 Gentgeen (Talk | contribs | block) (cats) (undo) * (cur) (last) 19:07, 19 October 2004 65.182.32.3 (Talk | block) (spelling) (undo) * (cur) (last) 23:05, 2 May 2004 Klaus (Talk | contribs | block) (My mother's recipe for curried rice.)

Edit history for Lentil Rice Load recipe
* (cur) (last) 22:47, 23 January 2008 Demi (Talk | contribs | block) (1,914 bytes) (→Procedure:  +onion... whoops!) (rollback | undo) * (cur) (last) 22:02, 18 January 2007 71.254.96.166 (Talk | block) (undo) * (cur) (last) 20:59, 26 October 2006 71.14.65.133 (Talk | block) (→Procedure) (undo) * (cur) (last) 10:21, 15 October 2006 Webaware (Talk | contribs | block) m (cat order) (undo) * (cur) (last) 11:00, 7 May 2006 Kellen (Talk | contribs | block) (+cat) (undo) * (cur) (last) 21:03, 1 March 2006 Demi (Talk | contribs | block) (→Procedure: forgot the egg!) (undo) * (cur) (last) 02:03, 24 November 2005 Demi (Talk | contribs | block) (→Ingredients: links) (undo) * (cur) (last) 02:02, 24 November 2005 Demi (Talk | contribs | block) m (→Ingredients: better link) (undo) * (cur) (last) 01:04, 24 November 2005 Demi (Talk | contribs | block) (→Ingredients: make list) (undo) * (cur) (last) 01:03, 24 November 2005 Demi (Talk | contribs | block) (New recipe)


text: User talk:206.48.0.60

title: User talk:206.48.0.60


text: Template:PD-US-patent

title: Template:PD-US-patent


text: Template:PD-US-patent-no notice

title: Template:PD-US-patent-no notice


text: Template:US patent

title: Template:US patent


text:
Talk:Blender 3D: Noob to Pro/Every Material Known to Man/Human Skin

I guess this works if you're white... what if you're not Caucasian?

Hello... where's the SSS? Skin has translucency, sub-surface scattering, more. Skin has WAY more settings than this. These skin methods are all trash.


text:
Talk:Indian Tipi

This book is a instructional guide.

Notes on references
Some books to use as a reference ...

Laubin, Reginald, Gladys Laubin, (Tatanka Wanjila na Wiyaka Wastewin) and Stanley Vestal, "The Indian tipi : its history, construction, and use". 2nd ed., Norman, University of Oklahoma Press, 1957. LCCN 57005958 ISBN 0-8061-2236-6

Holley, Linda A., Tipis | Tepees | Teepees: History, design, and evolution of the cloth tipi. Gibbs Smith, 2007 ISBN 978-1-58685-511-6

Goble, Paul, "Tipi: Home of the Nomadic Buffalo Hunters". World Wisdom, 2007. ISBN 193331639X

... Reddi (talk) 02:43, 26 March 2008 (UTC)

notes on source

 * Prairie Smoke by Melvin Randolph Gilmore 1921

title: Talk:Indian Tipi


text:
Cookbook talk:Babi Panggang Sauce

Uh, just throwing out an FYI -- "babi panggang" (yes, 2 g's) means roast pork in Bahasa Indonesia...I mean, I'm not commenting on the recipe itself, but based on the name, it appears the recipe itself out to be either be called something else (by its commonly accepted name in English or Chinese) or it should be moved from Chinese recipes. Or perhaps cross-referenced with southeast Asian (or Indonesian) recipes? Just a thought... --Aemera (talk) 02:55, 26 March 2008 (UTC)
 * I have requested a move of page based on the correct spelling --Voidvector (talk) 11:43, 7 May 2008 (UTC)

title: Cookbook talk:Babi Panggang Sauce


text: User talk:92.43.64.69

title: User talk:92.43.64.69


text:
User talk:Aemera

Welcome message
Welcome, Aemera!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 03:16, 26 March 2008 (UTC)

title: User talk:Aemera


text:
A-level Chemistry/OCR (Salters)/Metallic bonding

Metallic bonding is what holds metal atoms together in the solid and liquid states.

Metals contain delocalised electrons
The simplest description* of the bonding in metals consists of a lattice of metal cations in a sea of electrons.

A metal atom releases its valence electron(s) into the sea, but its core electrons remain localised around its nucleus. This extensive delocalisation of valence electrons is responsible for most of the properties of metals.

Physicists sometimes consider metals to consist of a 'gas' of electrons, free to flow around the regular arrangement of metal cations. In a metal, the valence electrons are free to roam throughout the whole structure, but cannot escape completely without getting extra energy from somewhere else.

Delocalised electrons conduct charge
Because the valence electrons in a metal are completely delocalised, they can flow through the metal if an electric field or circuit encourages them to. Electrical conduction consists of electrons flowing in a specific direction, and generally decreases at higher temperatures as the electrons collide more frequently with vibrating atoms.

Delocalised electrons help conduct heat
Electrons also help conduct heat through metals, supplementing the conduction that occurs in any solid as atoms bash into each other. Thermal conduction, in contrast to electrical conduction, consists of electrons moving in random directions and generally increases at higher temperatures as more frequent collisions help propagate thermal vibrations.

Metallic bonding is strong and flexible

 * Metals are malleable and ductile because metallic bonding is not directional
 * Metallic bonding does not oppose deformation because a change in the positions of the metal nuclei does not increase the energy of the structure

Covalent bonding is strong but inflexible

 * Covalent bonds, on the other hand, are only strong in certain directions and oppose deformation
 * Diamond is exceptionally hard because deforming it requires bond breaking, and it has many strong covalent bonds in all directions
 * Molecular solids, like sulfur, S8, have strong intramolecular covalent bonding but weak intermolecular bonding, so they are soft

Ionic bonding is strong but ionic solids are brittle

 * Ionic bonds are not directional either, but deforming an ionic solid pushes ions of the same charge closer together
 * The repulsion from these like charges either opposes any deformation
 * This explains why ionic solids are brittle - they will resist deformation strongly up to a point, but beyond that point, they fail

The strength of metallic bonds
The stronger the bonding in a metal, the higher its melting and boiling points will be. To melt a metal requires the metallic bonding to loosen, whereas boiling breaks almost all the metallic bonding (in the gas phase, metals exist either as single atoms or as small molecules or clusters, such as Li2).

Metallic bonding can be weak, but is more often strong. Atoms that contribute one electron to metallic bonding are weakly bonded and have low melting points. Atoms that contribute two electrons have much stronger metallic bonding and therefore much higher melting points

Strength of metallic bonding in Groups 1, 2 and 3
The Group 1 metals, Li-Cs, all have low melting points because they contribute only one electron per atom to metallic bonding. The Group 2 metals, Be-Ba, have moderate melting points since they release two electrons per atom to metallic bonding. Group 3 metals have high melting points, as they can provide three electrons per atom for metallic bonding.

Group 13 metals are weird
The Group 13 metals, B-Tl, do not seem to follow any pattern!

Boron is a metalloid and is ionically bonded — it is too electronegative to release its valence electrons for metallic bonding.

Al, Ga, In and Tl have different core electron configurations. Aluminium has a noble gas core, [Ne], but gallium and indium have "noble gas plus filled d subshell" cores, [Ar]3d10 and [Kr]4d10, respectively. Thallium has a "noble gas plus filled d and f subshells" core, [Kr]4f145d10.

The filled d and f subshells found in the cores of Ga, In and Tl are much less effective at shielding their valence electrons from their nuclei than filled s and p subshells are, because of the diffuse shapes of d and f orbitals. As a result, their valence electrons feel a stronger pull from the nucleus (a greater effective nuclear charge) and are less easily released for metallic bonding.

Strength of metallic bonding in transition metals
The transition metals almost all have very high melting and boiling points, since they have many valence electrons to contribute to metallic bonding. Excluding the sort-of-transition-sort-of-not metals Zn, Cd and Hg, the minimum melting point is 961 °C (silver), while the maximum is 3407 °C (tungsten, higher than all elements except carbon). The mean melting point of the transition metals is around 1900 °C.

Although the melting points of transition metals are high, the increase in melting point on moving from Group 3 to Group 4 is not as great as the increases seen on going from Group 1 to Group 2 and Group 2 to Group 3. Also, the melting points of the transition metals increase from left to right until around the middle of the d block, where they begin to decrease again.

Metals are uniquely useful
Metals and alloys that are strong are used as structural materials, most importantly iron (mostly as steel) and aluminium (alloyed with Mg, Si and/or Cu). While many materials are strong, metals and alloys are special because they are also elastic (can be deformed but will return to their original shape) and thus easy to shape (malleable, ductile and machinable). Other strong materials that are not metallically bonded are brittle rather than elastic, and may fracture too easily or be difficult to manufacture in the required shape.


text:
Muggles' Guide to Harry Potter/Magic/Griffin

Extended Description
A Griffin is a Magical Creature with the head and front legs of a giant eagle, and the body and back legs of a lion.

While documented in Muggle mythology, there is no Griffin in the Harry Potter series.


text:
A-level Chemistry/OCR (Salters)/Sulfur

Sulfur is the sixteenth element in the periodic table, lying below oxygen and above selenium in Group 16. Sulfur is in Period 3, with phosphorus to its left and chlorine to its right. Sulfur exists as a yellow solid, which contains eight-membered rings stacked together. This is in stark contrast with oxygen, which exists as the molecular gas dioxygen, O2, but similar to phosphorus and selenium.

Isotopes
95% of naturally occurring sulfur is sulfur-32, 32S. Most of the rest is sulfur-34, 34S. Two other stable isotopes exist, 33S and 36S. Sulfur's relative atomic mass is 32.065 ± 0.005.

Electron configuration
The electron configuration of the neutral sulfur atom, S, is

$$1\mbox{s}^2 2\mbox{s}^2 2\mbox{p}^6 3\mbox{s}^2 3\mbox{p}^4 \,\!$$

or in more compact notation,

$$[\mbox{Ne}] 3\mbox{s}^2 3\mbox{p}^4 \,\!$$

Electronegativity
Sulfur has an electronegativity of about 2.6, which is similar to carbon and selenium. Its electronegativity is greater than that of any metal or metalloid, and greater than that of the nonmetal phosphorus (2.2). The other non-metals (I, Br, Cl, N, O and F) are more electronegative.

Sulfides
Sulfur forms sulfides by direct reaction with metals:

 * Fe(s) + S(s) → FeS(s)

 * Zn(s) + S(s) → ZnS(s)

 * 2Li(s) + S(s) → Li2S(s)

 * 2Al(s) + 3S(s) → Al2S3(s)

Sulfides formally contain the sulfide ion, S2−, but the bonding in sulfides is somewhere in-between ionic and covalent, with some sharing of electrons between metal and sulfur. S2− is almost nonexistent in solution, because it is extremely basic and will remove a proton from almost anything. Consequently, sulfides are insoluble in all solvents, unless they react with the solvent to form something more soluble.

Organosulfur compounds

 * Sulfonic acids, RSO3H and sulfonates, RSO3−, covered in Colour by Design
 * Thioethers (sulfides), e.g. dimethyl sulfide, (CH3)2S, mentioned in The Oceans
 * Many other organic compounds containing sulfur exist, but they are not discussed in Salters Advanced Chemistry

title: A-level Chemistry/OCR (Salters)/Sulfur


text: User talk:F0ckT4rd

title: User talk:F0ckT4rd


text:
Muggles' Guide to Harry Potter/Magic/Hippocampus

Overview
Hippocampi are the equine equivalent of Muggle "mermaids": forequarters and head of a horse, and tail of a fish.

Extended Description
The Hippocampus is largely a Mediterranean beast, though a single example was caught off the coast of Scotland by Mermen in 1949.

Analysis
While the Hippocampus does not appear in the main story, it does appear in the stated form in Muggle mythology. The name has also been used to identify a part of the structure of the brain which is apparently somehow involved with the creation and storage of memories.


text: Muggles' Guide to Harry Potter/Magic/Horklump


text:
Muggles' Guide to Harry Potter/Magic/Jarvey

Overview
A Jarvey is a magical beast that looks like an overgrown ferret and can speak English, though this is apparently self-taught and consists mainly of swear words.


text:
Muggles' Guide to Harry Potter/Magic/Jobberknoll

Overview
The Jobberknoll is a tiny, largely mute, blue-speckled bird that eats insects.

Extended Description
According to "Newt Scamander", the Jobberknoll makes no sound until its death, at which time it releases a long scream composed of every sound it has ever heard, in reverse (and presumably sped up).

Analysis
"Scamander" also says that the feathers of the Jobberknoll are used in truth serums and memory potions. Presumably this is because of the Jobberknoll's ability to recall and replicate sound heard during its lifetime.

There is no mention of this creature in the seven main books of the series, and apart from its possible use as a potion ingredient, it does not play a role in the series at all.


text: Muggles' Guide to Harry Potter/Magic/Kappa


text: Muggles' Guide to Harry Potter/Magic/Lobalug


text: Muggles' Guide to Harry Potter/Magic/Mackled Malaclaw


text:
Muggles' Guide to Harry Potter/Magic/Mooncalf

Overview
An extremely shy creature that emerges from its burrow only at the full moon, the Mooncalf has a smooth, pale grey body, bulbous eyes on the top of its head, four spindly legs, and large, flat feet.

Extended Description
When they emerge from their burrows, mooncalves engage in complicated geometric dances, which are believed to be in some way related to mating. The patterns these dances leave in fields have mystified Muggle farmers and fueled many interstellar conspiracy theories.

If collected before sunrise, the silvery dung of the Mooncalf provides an extremely good fertilizer for magical herb and flower gardens.

Analysis
The term "mooncalf" actually appears in Muggle literature, typically used to refer to a lovestruck youth, always mooning after the object of his affections. Muggle mooncalves are not known either for their dancing ability or the quality of their droppings, though they often seem to trip over their own feet, as if they were overlarge, and can appear almost painfully shy, particularly if the one they are following happens to look at them.

Greater Picture
While mooncalves never directly appear in the principal seven books, we suspect there might be a passing reference made to "mooncalf dung" by Professor Sprout at some point in the series.


text:
Woodworking/Essential Hand Tools

While there probably isn't any truly "typical hobbyist woodworker", there are a number of tools that serve key roles in working with wood. While collecting tools over time, many woodworkers "make do" with a tool until they are fortunate enough to acquire a speciality tool for a given task.

A significant distinction should be noted at this point that, for some, the use of power tools is not considered because of their intention of relying exclusively on hand tools rather than taking advantage of common power tools such as a circular saw or electric drill. This author is not in that camp but has great respect for those that are able to adhere to such stringent standards. While it is personal decision as to whether or not one will use power tools, the time, effort, and skill needed to abstain from the modern convenience of electricity have never been in enough abundance for me to adopt such a vow of abstinence.

Collecting tools is absolutely a lifelong process though one usually doesn't realize that until many years of experience. Most woodworkers will go through phases of gathering as well as divesting themselves of various tools. In my case, my father gave me some basic auto repair tools when I graduated from high school and, while I still have some of that same set, many of those tools are long gone; either broken, loaned out never to be seen again, or lost in the tall grass where my kids took them out to play. It is, at times, a blessing to be forced to replace a tool.

The start of my collection included a number of screw drivers, a hammer, some wrenches, a ratchet set, pliers, and vice grips. For many years these served the sordid tasks of a young family man. My lack of both financial resources and experience forced me to be creative in the application of these basic tools. I still remember going to the store and finally noticing that there were different sizes of screw drivers than I had realized. And my lust for tools was born.

Hammers
Claw Hammer

Wood Mallet

Screw Drivers
Slotted, commonly referred to as Flat or Straight Head

Phillips Head

Square Drive

Torx Head

Drills, Bits and Augers
The most commonly used drill bits by carpenters are:

1) TWIST DRILL: A twist drill is used to bore holes for dowels. It bores a long clean hole.

2) CENTER BIT: A center bit is used to bore shallow holes. It is usually used to make up diameters of hole up to 50mm.

3) COUNTER SUNK BIT: A counter sunk bit is used for boring conical holes. It is used to facilitate easy receiving of screw heads.

4) AUGER BIT: An auger bit is used to bore holes in logs. Auger bits are available in sizes ranging from 6mm to 25mm.

title: Woodworking/Essential Hand Tools


text:
Talk:Woodworking/Essential Hand Tools

My name is Dan and this is my first contribution to any project of this type. I hope that the original author will somehow see that another contribution has been made and can weigh in on whether this contribution was in line with his original idea. Certainly it needs to be expanded and completed, but I hope it is a framework that will be useful. —Preceding unsigned comment added by Dbr4good (discuss • contribs) 07:31, 26 March 2008
 * Hi Dan, and welcome to Wikibooks. I really like what you've written, and please do add more if you feel like it.  One thing I might point out, however (it's a small thing): books should be written from what we call a neutral point of view, and so are written in the third person.  But don't take that as a criticism!  Keep on writing!  — Sam Wilson (Australia) 02:05, 6 June 2008 (UTC)

title: Talk:Woodworking/Essential Hand Tools


text:
User talk:Dbr4good

Welcome message
Welcome, Dbr4good!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 07:49, 26 March 2008 (UTC)

title: User talk:Dbr4good


text:
Cookbook:Pulao (Indian Rice Pilaf)

 * Rice Recipes

Pulao or pallao, is a rice dish from India, consisting of rice and a mixture of lentils, vegetables, mainly including peas, potatoes, French beans, carrots or meat, mainly chicken, fish, lamb, pork or beef. It is usually served on special occasions and weddings, though its not uncommon to eat it for a regular lunch or dinner meal.

Ingredients

 * Basmati rice
 * Vegetables (onion, carrot, beans, peas)
 * Ginger garlic paste
 * Ghee
 * Oil
 * Pulao mix (available in stores)
 * 1 tsp cumin seeds (zeera)
 * ½ tsp turmeric powder (haldi)
 * 1 tsp ginger paste (pisi adrak)
 * 1 tsp garlic paste (pisa lasan)
 * 1 tbsp lemon juice
 * 3 green chillies (slit into 2) (more or less may be used depending on taste preference)
 * 2 big black cardamoms (bari kaali ilaichi)
 * 3 bay leaves (tezz pattay)
 * 6 cloves (loung)
 * 2 cinnamon sticks (dal cheeni)
 * Salt

Procedure

 * 1) Clean and soak required quantity of basmati rice in water for about 45 minutes. After that, just keep it in cooker (without the pressure plug), so that you can open and see the consistency of rice being cooked. The rice should cook in about 15–20 minutes.
 * 2) Check for consistency where it's dry and non sticky, with single grains. Set rice aside.
 * 3) Boil all required vegetables and set aside.
 * 4) Cut onions into very thin slices.
 * 5) Heat ghee and/or oil in a pan. Add onions and ginger garlic paste and sauté them.
 * 6) After onions turn a little pink/brown, add all veggies, the pulao masala (proportional to the qty of rice taken), and salt. Mix them well and sauté for about 5–10 minutes; adding a little curd (yogurt) here is optional.
 * 7) After it gets to a dry gravy consistency, taste it to ensure it is correctly salted. Then, add the rice and mix it gently so as not to break the rice.
 * 8) Garnish this with raisins, cashews, and deep-fried onions.

title: Cookbook:Pulao (Indian Rice Pilaf)


text:
User talk:80.227.59.208

Also, please take a look at our Cookbook:Policy which has examples on recipe formatting. thanks, Webaware talk 08:00, 26 March 2008 (UTC)

title: User talk:80.227.59.208


text:
Talk:MIRC Scripting

This is the official page to discuss the mIRC Scripting wikibook as a whole. I want to make something a little bit fancier when I get the time later, but for now, just drop all your comments, criticisms, suggestions, questions, etc, all under one place.

title: Talk:MIRC Scripting


text:
Cookbook:Rye Bread

| Cuisine of Denmark | Breakfast

Rye bread (Danish: rugbrød) is a type of bread common to Northern Europe in many varieties, but almost unknown in the south. This version is a typical Danish example. In Denmark, most people eat this type of bread on a daily basis.

Ingredients

 * 1500 g rye flour
 * 1000 g cracked rye seeds
 * 5 tsp salt
 * About 2 L water
 * 300 ml sourdough starter

Procedure

 * 1) Mix the salt with the rye flour in a big bowl.
 * 2) Add 1.8 L of the water and mix it.
 * 3) Mix in the sourdough starter. The result should be wet enough to flow very slowly.
 * 4) Cover it with a cloth and let it rise for at 12–30 hours as convenient. Then add the cracked rye seeds.
 * 5) If the resulting dough feels dry, add a bit of water. The result should be just dry enough to retain an approximate shape, but no drier.
 * 6) Take out 300 ml of dough to act as the starter next time you make this recipe.
 * 7) Butter 3 bread forms and put the dough into it, forcing it into all corners with a spoon. Then using a fork, make deep holes as close as you can all over the bread.
 * 8) Let it rise for 5–10 hours, and then bake it for about 90 minutes at about 180°C.
 * 9) Let the bread cool for 15 minutes, and then tip them out to cool further on a table.
 * 10) The loaves can keep for about a week in a plastic bag. Do not refrigerate.

Notes, tips, and variations

 * The bread is very difficult to cut for 2 hours or so after baking. Allow to cool before slicing.

title: Cookbook:Rye Bread


text:
User talk:Albaab

Welcome, Albaab!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 02:29, 27 March 2008 (UTC)

Digitale forteljingar

 * Do not remove it this time. - Anonymous Dissident  Talk 12:52, 26 March 2008 (UTC)

title: User talk:Albaab


text:
User talk:193.145.150.33

Join Us!
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title: User talk:193.145.150.33


text:
User talk:Esben~enwikibooks

Welcome message
Welcome, Esben!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 11:39, 26 March 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 Esben. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Esben~enwikibooks 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 23:09, 17 March 2015 (UTC)

Renamed
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title: User talk:Esben~enwikibooks


text: User talk:58.168.35.209

title: User talk:58.168.35.209


text:
User talk:Sanderbrun~enwikibooks

Welcome, Sanderbrun!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:27, 26 March 2008 (UTC)

Digitale forteljingar
As the is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:27, 26 March 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 Sanderbrun. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Sanderbrun~enwikibooks 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) 05:27, 19 April 2015 (UTC)

title: User talk:Sanderbrun~enwikibooks


text:
User talk:Torbsels~enwikibooks

Welcome, Torbsels!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:27, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:27, 26 March 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 Torbsels. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Torbsels~enwikibooks 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 23:50, 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) 05:36, 19 April 2015 (UTC)

title: User talk:Torbsels~enwikibooks


text:
User talk:Fallos~enwikibooks

Welcome, Fallos!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:27, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:27, 26 March 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 Fallos. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Fallos~enwikibooks 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 23:12, 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) 04:58, 19 April 2015 (UTC)

title: User talk:Fallos~enwikibooks


text:
User talk:Odau~enwikibooks

Welcome, Odau!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:27, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:27, 26 March 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 Odau. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Odau~enwikibooks 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 23:32, 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) 05:19, 19 April 2015 (UTC)

title: User talk:Odau~enwikibooks


text:
User talk:Frivan

Welcome, Frivan!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:28, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:28, 26 March 2008 (UTC)

title: User talk:Frivan


text:
User talk:Staaker~enwikibooks

Welcome, Staaker!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:28, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:28, 26 March 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 Staaker. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Staaker~enwikibooks 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 23:47, 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) 05:32, 19 April 2015 (UTC)

title: User talk:Staaker~enwikibooks


text:
User talk:Erlend Kjørlaug Larsen

Welcome, Erlend Kjørlaug Larsen!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:28, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:28, 26 March 2008 (UTC)

title: User talk:Erlend Kjørlaug Larsen


text:
User talk:Kaerrein~enwikibooks

Welcome, Kaerrein!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. -- Herby talk thyme 12:29, 26 March 2008 (UTC)

Digitale forteljingar
As this is "English" Wikibooks I cannot see how this page is relevant here. I think it likely that it will be deleted unless an explanation is given. Thanks -- Herby talk thyme 12:29, 26 March 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 Kaerrein. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Kaerrein~enwikibooks 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 23:18, 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) 05:07, 19 April 2015 (UTC)

title: User talk:Kaerrein~enwikibooks


text: Category:Book:Introduction to Psychology


text:
German/Level III/Das Ruhrgebiet

Lektion Zehn für Fortgeschrittene

Text 10-3 ~ Das Ruhrgebiet
Das Ruhrgebiet ist die wichtigste Industrielandschaft Deutschlands. Große Steinkohlevorkommen bildeten die Grundlage für die Eisenindustrie, für chemische Werke und viele andere Industriezweige. Der Rhein, der Rhein-Herne-Kanal und der Dortmund-Ems-Kanal sind günstige Wasserverkehrswege. Die wichtigsten Großstädte des Ruhrgebietes sind Dortmund, Essen, Duisburg, Gelsenkirchen und Bochum.

Extra Material

 * Artikel über das Ruhrgebiet in der Deutschen Wikipedia

title: German/Level III/Das Ruhrgebiet


text:
Indian Tipi/Tipi History

Native Americans in the United States are the indigenous peoples from the regions of North America now encompassed by the continental United States, including parts of Alaska. They comprise a large number of distinct tribes, states, and ethnic groups, many of which still endure as political communities. There is a wide range of terms used, and some controversy surrounding their use: they are variously known as American Indians, Indians, Amerindians, Amerinds, or Indigenous, Aboriginal or Original Americans.

A tipi is a conical tent originally made of animal skins or birch bark and wood found in the northwest called lodge pole pine. It is a skill and hard work to make so many long poles of the same length with a gentle taper that end in a point. It was popularized by the Native Americans of the Great Plains. The European form of the term is teepee or tepee. The word "tipi" comes into English from the Lakota language; the word thipi consists of two elements: the verb thí, meaning "to dwell," and a pluralizing enclitic (a suffix-like ending that marks the subject of the verb as plural), pi, and means "they dwell." In Lakota, formal verbs can be used as nouns, and this is the case with thípi, which in practice just means "house."

Tipis are stereotypically associated with Native Americans in general, but Native Americans from places other than the Great Plains used different types of dwellings. Long before the Sioux, Cheyenne, and other Plains tribes came to the grasslands, this type of shelter had been developed by the Indians of the northern forests. They used a pole frame to create the conical shape and then covered the skeleton with birchbark, caribou hides, or other materials. The term wigwam is sometimes used to refer to a dwelling of this type.

The Plains Indians adapted this basic structure to their own environment and their own pattern of living. The Great Plains are the broad expanse of prairie and steppe which lie east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S. states of Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas and Wyoming, and the Canadian provinces of Alberta, Manitoba and Saskatchewan. In Canada the term prairie is more common, and the region is known as the Prairie Provinces or simply "the Prairies". While in essential features the tipis of all Plains tribes were the same, there were nevertheless some important differences. Thus, when setting up a tipi, the Blackfoot, Crow, Sarsi, Hidatsa, Omaha, and Comanche first tie four poles as a support to the others; while the Teton-Dakota, Assiniboin, Cheyenne, Gros Ventre, Arapaho, Kiowa, Plains-Cree, Mandan, and Pawnee use three, or a tripod foundation. For the remaining tribes, we lack data, but it seems safe to assume that they follow one or the other of these methods. The three-pole foundation gives the projecting tops of the poles a spiral appearance while the four-pole beginning tends to group them on the sides. Thus, to a practised eye, the difference is plain. The covers, ears, doors, etc., are quite similar throughout. The shapes of tipis, however, show some differences. Thus, the Cheyenne prefer a wide base in proportion to the height while the Arapaho prefer a narrow base. Again, the Crow use very long poles, the ends projecting out above like a great funnel.

The tipi was used through out this area. An adjustment in the framework was made to accommodate the strong winds of the region, and buffalo hides, sewn together, became the usual covering. The Plains Indians had deep appreciation for the tipi. Secure, mobile, and comfortable, it was looked upon by these nomadic hunters as “a good mother” who sheltered and protected her children.

The nomadic tribes survived on hunting, and the bison was their main food source. American buffalo, or simply buffalo, is the commonly used (but inaccurate) name for the American Bison. These animals were the largest source of items such as food, cups, decorations, crafting tools, knives, and clothing. The tipi was an ideal dwelling for the Plains people. Like the buffalo they hunted, these Indians were constantly on the move. Their dwellings, therefore, had to be readily transportable.

The tribes kept moving following the migration of the bison. The Plains Indians lived in tipis because they are easily disassembled and so allow a lifestyle of following game. The tipi was durable, provided warmth and comfort in winter, was dry during heavy rains, and was cool in the heat of summer. Tipis could be disassembled and packed away quickly when a tribe decided to move, and could be reconstructed quickly when the tribe settled in a new area. To move it, the ends of two of the tipi supporting poles were lashed to a horse. The other ends dragged along the ground, thus forming a roughly triangular frame, a travois, on which the buffalo covering and the family’s other possessions were tied. At the new campsite, several long poles were bound together near their tops. This portability was important to those Plains Indians who had a nomadic lifestyle.

The poles were then stood up and slanted outward from this center tie to form the outline of a cone. Other poles were leaned gainst this framework to strengthen it, and a buffalo-hide covering, usually of 8 to 20 skins, was draped over the skeleton. The covering was joined near the top with wooden lodge pins, as shown below. An opening was left at the very top as a smoke hole; the entrance, with closable flaps, was at the lower part of this seam.

In hot weather, when cooling breezes were wanted, the flaps were left open and the lower part of the tipi covering was rolled up, permitting the air to circulate freely. In winter an additional skin lining was added to the tipi covering, thus providing insulation. The fire that burned in the center of the floor kept the tipi warm as well as furnishing heat for cooking. Because of the strong, prevailing winds that swept across the Plains from the west, a tipi was always set up with the entrance facing east. And the entire shelter was always tilted slightly toward the east to streamline the rear, thus lessening the wind pressure on it.

A typical tipi had a hide bedding, a rug for the baby, willow-rod backrests, cradle board, a suspended cooking bag, a supply of fuel, parfleches containing feed, medicine, and other necessities, and similar household gear. On the insulating lining of the tipi were hung sacred objects, weapons, shield, and other items. This lining was often painted with brilliantly colored designs that recalled past events in the lives of those who inhabited the tipi.

Modern tipi covers are usually made of canvas. Contemporary users of tipis include historical reenactors, back-to-the-land devotees, and Native American families attending Powwows or Encampments who wish to preserve and pass on a part of their heritage and tradition.

title: Indian Tipi/Tipi History


text:
Talk:Ada Programming/GNU Build System

Environment Variables
ADA_PROJECT_PATH

A directory list to be searched for GNAT project files.

ADA_INCLUDE_PATH

A directory list to be searched for Ada source files.

ADA_OBJECT_PATH

A directory list to be searched for object, library and Ada library information files

ADA

Ada compiler executable. It is usually "gnatgcc" or "gcc".

ADAFLAGS

Flags to be passed to $ADA

GNATMAKE, GNATBIND, GNATLINK, etc.

GNATMAKEFLAGS, GNATBINDFLAGS, GNATLINKFLAGS, etc.

GNAT toolsuite executables and their respective flags.

CCLD, CXXLD

Linker with cc style interface used to build binaries. $CXX is used instead of $CC whenever a project contain any piece of C++ code.

CCLDFLAGS, CXXLDFLAGS

Flags to be passed to $CCLD and $CXXLD

LIBS

(draft) Library search paths and library names

Configure script's responsibilities
These responsibilities are just a draft. Most of the Ada packages don't follow them.

$ADA is sometimes called $ADAC instead. configure SHALL handle $ADAC as well. configure MUST favor ADA over ADAC.

Maintainers must not use GNATMAKEFLAGS to store gnatbind flags or gnatlink flags etc. Instead, build automation system MUST handle $GNATBINDFLAGS etc. presence and construct resulting gnatmake command line. It MUST also handle $CCLD and $CCLDFLAGS presence. $CXXLD is invoked explicitly so it is not possible to forget about it.

title: Talk:Ada Programming/GNU Build System


text:
User talk:193.164.114.4

February 2011
We welcome and appreciate your contributions, but your recent edits to Muggles' Guide to Harry Potter had to be undone. Please see What is Wikibooks? to learn more about what contributions are beneficial to Wikibooks. Please be aware that some edits can be considered vandalism, use the sandbox for any test edits you would like to make, and read the welcome page to learn more about contributing constructively to this project. Thank you. Pmlineditor (t · c · l) 10:10, 3 February 2011 (UTC)

title: User talk:193.164.114.4


text: User talk:165.155.200.81

title: User talk:165.155.200.81


text:
User talk:70.79.90.35

Join Us!
--Webaware talk 14:03, 26 March 2008 (UTC)

title: User talk:70.79.90.35


text:
Wikijunior:Famous Inventors/Inventors in Communication

Inventors in Communication

 * Telephone
 * /Alexander Graham Bell/
 * /Samuel Morse/

 * Radio
 * /Nikola Tesla/
 * /Guglielmo Marconi/


text:
Parrot Virtual Machine

The Parrot Virtual Machine is a runtime engine for use with dynamic programming languages such as Perl, Python, Ruby and PHP. While originally designed for use with version 6 of the Perl programming language, it has expanded to a general-purpose dynamic virtual machine to host multiple high-level languages.

Parrot has been designed, in part, for ease of use by programmers and language designers. A series of tools called the Parrot Compiler Tools (PCT) have been designed that facilitate the creation of new languages for Parrot. These tools aide in creating new dynamic programming languages or implementing old languages on Parrot.

This book is going to introduce the reader to the Parrot Virtual Machine and the Parrot programming environment. We will discuss the creation of programs in the PIR and PASM languages and we will also discuss how to create new languages that compile to the Parrot platform. We will also talk about Parrot itself, and introduce the reader to Parrot's internals, which are released under an open source license and can be modified by able volunteers.

Introduction To Parrot

 * Introduction
 * Building Parrot
 * Running Parrot

Programming For Parrot

 * Parrot Programming
 * Parrot Assembly Language
 * Parrot Intermediate Representation
 * Polymorphic Containers (PMCs)
 * Multithreading and Concurrency
 * Exception Handling
 * Classes and Objects
 * The Parrot Debugger

Parrot Compiler Tools

 * Parrot Compiler Tools
 * Parrot Grammar Engine
 * Not Quite Perl
 * Optables and Expressions
 * Advanced PGE
 * Building A Compiler
 * HLL Interoperation

Parrot Hacking

 * Parrot Internals
 * IMCC and PIRC
 * Run Core and Opcodes
 * Memory and Garbage Collection
 * PMC System
 * String System
 * Exception Subsystem
 * IO Subsystem
 * JIT and NCI
 * Parrot Embedding
 * Extensions
 * Packfiles

Appendices

 * PIR Reference
 * PASM Reference
 * PAST Node Reference
 * Languages on Parrot
 * HLLCompiler Class
 * Command Line Options
 * Built-In PMCs
 * Bytecode File Format
 * VTABLE List

"Squaak" Language Tutorial

 * Squaak Tutorial
 * Introduction
 * Poking in Compiler Guts
 * Squaak Details and First Steps
 * PAST Nodes and More Statements
 * Variable Declaration and Scope
 * Scope and Subroutines
 * Operators and Precedence
 * Hashtables and Arrays
 * Wrap-Up and Conclusion

Resources

 * Resources
 * Licensing

Виртуальная машина Parrot

title: Parrot Virtual Machine


text:
Template:Parrot Virtual Machine/Page

 Parrot Virtual Machine

title: Template:Parrot Virtual Machine/Page


text:
Parrot Virtual Machine/Resources

Resources
These blog posts are released into the public domain and can be adapted directly:
 * http://www.parrotblog.org/2008/03/targeting-parrot-vm.html
 * http://www.parrotblog.org/2008/03/episode-2-poking-in-compiler-guts.html
 * http://www.parrotblog.org/2008/03/episode-3-squaak-details-and-first.html
 * http://www.parrotblog.org/2008/03/episode-4-past-nodes-and-more.html
 * http://www.parrotblog.org/2008/03/episode-5-variable-declaration-and.html
 * http://www.parrotblog.org/2008/03/episode-6-scope-and-subroutines.html
 * http://www.parrotblog.org/2008/03/episode-7-operators-and-precedence.html
 * http://www.parrotblog.org/2008/03/episode-8-hashtables-and-arrays.html

Other Resources
 * Parrot Documentation
 * Parrot Design Docs
 * Parrot Project Home

title: Parrot Virtual Machine/Resources