text:
A-level Physics/Forces and Motion/Force, work and power

Work
Work is a special name given to the (scalar) quantity

$$ W = \int \vec{F} \cdot d\vec{x}.$$

where $$W$$ is work and $$F$$ is force on the object and $$x$$ is displacement. Essentially this integral is the component of the force in question in the direction of the displacement, times the displacement. If the force is constant and the object travels in a straight line, this reduces to

$$W = \vec{F} \cdot \vec{x} = Fx \cos \theta \ $$

where $$W$$ is work and $$F$$ is force on the object and $$x$$ is displacement. Take note of the dot product.

We say that W is the "work done by the force, F." Notice that $$F$$ need not be the total force on an object, just the force we are looking at. It makes sense to ask what is the work done by a given force on an object. Notice also that the work done by the sum of two forces acting on an object is the sum of the work done by the forces acting individually on the object. This gives rise to the interpretation that work is that it is the energy transferred to the body by a force that acts on it. (Of course negative work is energy transferred from the body). This is the whole point of even considering work.

For, say we had a total force $$\vec{F}$$ acting on an object. Then the work is

$$ \int \vec{F} \cdot d\vec{r} = \int m \frac{d \vec{v}}{dt} \cdot d\vec{r} = m \int \frac{d\vec{v}}{dt} \cdot \vec{v} dt = m \int \vec{v} \cdot d\vec{v} = \Delta \left(\frac{1}{2}mv^2\right) = \Delta KE $$

This simply uses Newton's second law in the first step and a substitution in the integral. This states that the work done by the total force on an object is the change in kinetic energy of the object. For example, if you hold an apple, then move the apple down a little bit then stop, what is happening? Surely the potential energy of the apple has changed, so someone is doing work even though there is no change in kinetic energy—how can that be? We must consider all the forces. Gravity did work on the apple, but the apple did work on you (you did negative work on the apple) -- you have absorbed the energy! So there really is no paradox after all.

In a very special case, it happens that the quantity of work does not depend on how you move a particle around, but only on the beginning and ending points. Such a field is called "conservative." It means that we can introduce a potential. Gravity is such a conservative force, amazingly, which is why we can talk about the "potential energy" of an object. It is just shorthand for saying the work it takes to move the object from somewhere (the reference point) to wherever we are talking about. Consequently, the change in kinetic energy equals the negative change in potential energy, which basically states that the total energy of the system is constant. This is in fact why such a force is called conservative—it conserves mechanical energy!

Dissipative forces, such as friction (it always eats up energy) are sometimes called non-conservative forces. This is somewhat of a mistake because on the molecular level, the forces really are conservative. However, it is often nicer to just say that energy is not conserved in a given scenario, even though we know full well that it is disappearing into the motion of atoms, or heat. You will hear many people say that energy is not conserved in a given situation, but of course it is; energy is always conserved.

It turns out that a force is conservative if and only if the force is "irrotational," or "curl-less" which has to do with vector calculus. But for all of our purposes, there are no non-conservative forces!

However, just to quantify everything, we have the work done by a non conservative force is the change in the total energy of the body.

Power
Power is the rate of doing work. Thus we have

$$P = \frac{dW}{dt}$$

So,

$$P = \frac{d}{dt}(\vec{F} \cdot \vec{x})$$,

and for forces that do not vary over time becomes

$$P = \vec{F} \cdot \frac{d\vec{x}}{dt} = \vec{F} \cdot \vec{v}$$.

This means that if the force is acting perpendicular to the velocity, the speed does not change, because the work is zero so the change in kinetic energy is zero. But wait, how can that be, since a force necessarily accelerates something? It is accelerating it, it is changing the direction of travel—acceleration means the derivative of the vector velocity, not the magnitude of velocity. In fact, this tells us that the component of force in the same direction as velocity is responsible for (and only for) changes in the magnitude of the velocity, and the component of force perpendicular to the velocity is responsible for (and only for) changes in the direction of the velocity. Just to quantify this a little bit, it can be shown that

$$\vec{a} = ||v|| \vec{T} + \frac{||v||^2}{\rho} \vec{N}$$

where a is acceleration, v is the velocity, T is the unit tangent vector (tangent to the path of the particle and consequently parallel to the velocity vector), N is the unit normal vector (perpendicular to the tangent vector and in the direction of the derivative of the tangent vector, which you can picture by drawing two pretty close tangent vectors on a curve), and $$\rho$$ is the radius of curvature, which is essentially the radius of the circle which closest fits the path at the point (the radius of curvature of a circle is the radius of the circle, and the radius of curvature of a straight line is infinity). All this business is not really necessary for understanding physics, but if you understand it, it will help you understand what is going on. Notice that the second term is the centripetal acceleration—this is in fact where we get the formula for it.

Finally, just writing out the definition of power to look pretty, if the work is done at a changing rate, then

$$ P = \frac{dW}{dt} $$

If the work is done at a constant rate, then this becomes

$$ P = \frac{W}{\Delta t} = \frac{\Delta E}{\Delta t} $$.

Pressure
Pressure is the force per unit area.

$$ P = \frac{F}{A}$$

Torque
$$ \vec{\tau} = \vec{r} \; \mathbf{x} \; \vec{F} \ $$

$$ \tau = rF \sin \theta \ $$

Torque is the "rotational force" applied as part of circular motion, such as the force making the wheels of a car turn. In the SI unit system, torque is measured in Newton-metres.


text:
Numerical Methods/Solution of Linear Equation Systems

Definitions and Basics
A linear equation system is a set of linear equations to be solved simultaneously. A linear equation takes the form

 * $$a_1*x_1+a_2*x_2+\ldots+a_n*x_n=b \quad ,\,$$

where the $$n+1 \,$$ coefficients $$a_0 \ldots a_n \,$$ and $$b \,$$ are constants and $$x_1 \ldots x_n \,$$ are the n unknowns. Following the notation above, a system of linear equations is denoted as

 * $$\begin{matrix}

a_{11}*x_1+a_{12}*x_2+\ldots+a_{1n}*x_n & = & b_1 & \\ a_{21}*x_1+a_{22}*x_2+\ldots+a_{2n}*x_n & = & b_2 & \\ &\vdots&  & \\ a_{m1}*x_1+a_{m2}*x_2+\ldots+a_{mn}*x_n & = & b_m & \quad. \end{matrix}\,$$

This system consists of $$m \,$$ linear equations, each with $$n+1 \,$$ coefficients, and has $$n \,$$ unknowns which have to fulfill the set of equations simultaneously. To simplify notation, it is possible to rewrite the above equations in matrix notation:

 * $$\mathbf{A}\cdot\mathbf{x}=\mathbf{b}\quad .\,$$

The elements of the $$m \times n \,$$ matrix $$\mathbf{A} \,$$ are the coefficients of the equations, $$a_{ij} \,$$ and the vectors $$\mathbf{x} \,$$ and $$\mathbf{b} \,$$ have the elements $$x_i \,$$ and $$b_i \,$$ respectively. In this notation each line forms a linear equation.

Over- and Under-Determined Systems
In order for a solution $$\mathbf{x}\,$$ to be unique, there must be at least as many equations as unknowns. In terms of matrix notation this means that $$m \ge n \,$$. However, if a system contains more equations than unknowns ($$m>n$$) it is very likely (not to say the rule) that there exists no solution at all. Such systems are called over-determined since they have more equations than unknowns. They require special mathematical methods to solve approximately. The most common one is the Least-Squares-Method which aims at minimizing the sum of the error-squares made in each unknown when trying to solve a system. Such problems commonly occur in measurement or data fitting processes.

example

''Assume an arbitrary triangle: suppose one measures all three inner angles $$\alpha, \beta, \gamma$$ with a precission of $$\pm 0.2^{\circ}\,$$. Furthermore assume that the lengths of the sides a, b and c are known exactly. From trigonometry it is known, that using the law of cosines one can compute the angle or the length of a side if all the other sides and angles are known. But as is known from geometry, the inner angles of a planar triangle always must add up to $$180^\circ \,$$. So we have three laws of cosines and the rule for the sum of angles. Makes a total of four equations and three unknowns which gives an over-determined problem.''

On the other hand, if $$m<n\,$$ the problem arises, that the solution is not unique, as one unknown can be freely chosen. Again, mathematical methods exist to treat such problems. However, they will not be covered in this text.

This chapter will mainly concentrate on the case where $$m=n\,$$ and assumes so unless mentioned otherwise.

Exact Solution of Linear Systems
Solving a system $$\mathbf{A x} = \mathbf{b} \,$$ in terms of linear algebra is easy: just multiply the system with $$\mathbf{A}^{-1}$$ from the left, resulting in $$\mathbf{x}=\mathbf{A}^{-1}\mathbf{b}$$. However, finding $$\mathbf{A}^{-1}$$ is (except for trivial cases) very hard. The following sections describe methods to find an exact (up to rounding-errors) solution to the problem.

Diagonal and Triangular Systems
A diagonal matrix has only entries in the main diagonal:

 * $$a_{ij}\equiv 0 \; \forall \; i \neq j$$

The inverse of $$\mathbf{A}$$ in such a case is simply a diagonal matrix with inverse entries, meaning

 * $$\mathbf{A}^{-1} = \mbox{diag}(1/a_{ii})\quad .$$

It follows, that a diagonal system has the solution $$x_i = b_i/a_{ii}$$ which is very easy to compute.

An upper triangular system is defined as

 * $$a_{ij}=0 \quad \forall j < i \quad,$$

and a lower triangular system as

 * $$a_{ij}=0 \quad \forall j > i \quad.$$

Backward-substitution is the process of solving an upper triangular system

x_i = \begin{cases} b_i / a_{ii} \quad & \mbox{if} \; i=N \\ \frac{1}{a_{ii}}\left( b_i - \sum_{j=i+1}^{N}{a_{ij} x_j} \right) \quad &\mbox{else} \quad. \end{cases} $$

Backward-substitution on the other hand is the same procedure for lower triangular systems

x_i = \begin{cases} b_i / a_{ii} \quad & \mbox{if} \; i=1 \\ \frac{1}{a_{ii}}\left( b_i - \sum_{j=1}^{i-1}{a_{ij} x_j} \right) \quad &\mbox{else} \quad. \end{cases} $$

Gauss-Jordan Elimination
Instead of finding $$\mathbf{A}^{-1}$$ this method relies on row-operations. According to the laws of linear algebra, the rows of an equation system can be multiplied by a constant without changing the solution. Additionaly the rows can be added and subtracted from one another. This leads to the idea of changing the system in such a way that $$\mathbf{A}$$ has a structure which allows for easy solving for $$\mathbf{x}$$. One such structure would be a diagonal matrix as mentioned above.

Gauss-Jordan Elimination brings the matrix $$\mathbf{A}$$ into diagonal form. To simplify the procedure, one often uses an adapted scheme. First, the matrix $$\mathbf{A}$$ and the right-hand vector $$\mathbf{b}$$ are combined into the augmented matrix

\left [ \mathbf{A},\mathbf{b} \right ] = \begin{bmatrix} a_{11} & a_{12} & \cdots a_{1N} & b_1 \\ \vdots & \ddots & \vdots       & \vdots \\ a_{N1} & a_{N2} & \cdots a_{NN} & b_N \end{bmatrix} $$

To illustrate, consider an easy to understand, yet efficient algorithm can be built from four basic components:

 * gelim: the main function iterates through a stack of reduced equations building up the complete solution one variable at a time, through a series of partial solutions.

 * stack: calls reduce repeatedly, producing a stack of reduced equations, ordered from smallest (2 elements, such as ) to largest.

 * solve: solves for one variable, given a reduced equation and a partial solution. For example given the reduced equation and the partial solution, w = (d - bx - cy)/a. Now the partial solution is available for the next round, e.g. .

 * reduce: takes the first equation off the top and pushes it onto the stack; then produces a residual - a reduced matrix, by subtracting the elements of the original, first equation from corresponding elements of the remaining, lower equations, e.g. b[j][k]/b[j][0] - a[k]/a[0]. As you can see, this eliminates the first element in each of the lower equations by subtracting one from one, and only the remaining elements need be kept - ultimately, the residual is an output matrix with one less row, and one less column than the input matrix. It is then used as the input for the next iteration.

It should be noted that multiplication could also be used in place of division; however, on larger matrices (e.g. n=10), this has a cascading effect producing NAN's (infinities). The division, looked at statistically, has the effect of normalizing the reduced matrices - producing numbers with a mean closer to zero and a smaller standard deviation; for randomly generated data, this produces reduced matrices with entries in the vicinity of +-1.

Continuation still to be written

As it is, it shows that it isn't necessary to bring a system into full diagonal form. It is sufficient to bring it into triangular (either upper or lower) form, since it can then be solved by backward or forward substitution respectively.

LU-Factorization

 * This section needs to be written

Approximate Solution of Linear Systems

 * This section needs to be written

Jacobi Method
It is an iterative scheme.

Gauss-Seidel Method

 * This section needs to be written

10v+w+x-2y+z=-1 v-20w-2x+y+z=20 v+w+10x-y-z=-1 -v-2w+x+50y+z=2 v+w+x+y+100z=-1 ;find result:

SOR Algorithm
SOR is an abbreviation for the Successive Over Relaxation. It is an iterative scheme that uses a relaxation parameter $$\omega$$ and is a generalization of the Gauss-Seidel method in the special case $$\omega=1$$.

Given a square system of n linear equations with unknown x:

 * $$A\mathbf x = \mathbf b$$

where:

 * $$A=\begin{bmatrix} a_{11} & a_{12} & \cdots & a_{1n} \\ a_{21} & a_{22} & \cdots & a_{2n} \\ \vdots & \vdots & \ddots & \vdots \\a_{n1} & a_{n2} & \cdots & a_{nn} \end{bmatrix}, \qquad \mathbf{x} = \begin{bmatrix} x_{1} \\ x_2 \\ \vdots \\ x_n \end{bmatrix}, \qquad  \mathbf{b} = \begin{bmatrix} b_{1} \\ b_2 \\ \vdots \\ b_n \end{bmatrix}.$$

Then A can be decomposed into a diagonal component D, and strictly lower and upper triangular components L and U:

 * $$A=D+L+U, $$

where
 * $$D = \begin{bmatrix} a_{11} & 0 & \cdots & 0 \\ 0 & a_{22} & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \cdots & a_{nn} \end{bmatrix}, \quad L = \begin{bmatrix} 0 & 0 & \cdots & 0 \\ a_{21} & 0 & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\a_{n1} & a_{n2} & \cdots & 0 \end{bmatrix}, \quad U = \begin{bmatrix} 0 & a_{12} & \cdots & a_{1n} \\ 0 & 0 & \cdots & a_{2n} \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \cdots & 0 \end{bmatrix}. $$

The system of linear equations may be rewritten as:

 * $$(D+\omega L) \mathbf{x} = \omega \mathbf{b} - [\omega U + (\omega-1) D ] \mathbf{x} $$

for a constant ω > 1.

The method of successive over-relaxation is an iterative technique that solves the left hand side of this expression for x, using previous value for x on the right hand side. Analytically, this may be written as:

 * $$ \mathbf{x}^{(k+1)} = (D+\omega L)^{-1} \big(\omega \mathbf{b} - [\omega U + (\omega-1) D ] \mathbf{x}^{(k)}\big). $$

However, by taking advantage of the triangular form of (D+ωL), the elements of x(k+1) can be computed sequentially using forward substitution:

 * $$ x^{(k+1)}_i = (1-\omega)x^{(k)}_i + \frac{\omega}{a_{ii}} \left(b_i - \sum_{j>i} a_{ij}x^{(k)}_j - \sum_{j<i} a_{ij}x^{(k+1)}_j \right),\quad i=1,2,\ldots,n. $$

The choice of relaxation factor is not necessarily easy, and depends upon the properties of the coefficient matrix. For symmetric, positive-definite matrices it can be proven that 0 < ω < 2 will lead to convergence, but we are generally interested in faster convergence rather than just convergence.

Conjugate Gradients

 * This section needs to be written

Multigrid Methods

 * This section needs to be written

Main Page - Mathematics bookshelf - Numerical Methods

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


text:
Jet Propulsion/Nozzles

The exhaust gases (and the bypass air in turbofans) are expanded and accelerated through nozzles, accelerating the flow, by reducing the static pressure of the stream, and provides propulsive force. Convergent nozzles have a progressive reduction in flow area and are used to accelerate flows to subsonic velocities. Convergent-divergent nozzle enable supersonic exit velocities provided a sufficient pressure differential exists.

The common view is that nozzles provide most of the thrust in practice there is often significant thrust provided by the pressure differentials across other components of the engine such as intakes.

Thrust vectoring nozzles direct the exhaust laterally to provide lateral thrust. Thrust reversers redirect the exhaust forwards to provide braking.

Gas Turbines
A gas turbine (GT) engine or jet engine is used not only in aircraft but also in various other contrivances power generation, ships and even battle tanks (the US M1A2 Abrams tank uses a 1000 hp gas turbine). In these cases, the nozzle design isn't of much importance because the engine is not used for providing any thrust. In fact, these GT engines are replacements to the usual piston engine because of the high power to weight ratio. Hence the shaft of the GT is coupled to the required contivace, say a generator or a propeller or a gearbox.The exhaust gases from a GT engine in these scenarios get the same treatment that the exhaust gases from the piston engine.

But when the same GT engine is used in an aircraft a nozzle is used because the hot exhaust gases coming out of the GT will have very high pressure which will in turn propel the aircraft forward in accordance to Newton's 3rd Law of motion which states that "EVERY ACTION HAS AN EQUAL AND OPPOSITE REACTION".
 * Action> Hot gases at high pressure from nozzle.
 * Reaction--> The aircraft being propelled forward.

Nozzles were, until recently, only used for proving thrust but now modified nozzles are being used for changing the course of the aircraft which was traditionally done only using aileron and tail fins.

title: Jet Propulsion/Nozzles


text:
Diagnostic Radiology/Chest Imaging/Chest Signs

Be able to define, identify and state the significance of the following on a radiograph:

 * air bronchogram - indicates a parenchymal process, including non-obstructive atelectasis, as distinguished from pleural or mediastinal processes
 * air crescent sign - indicates a lung cavity, often due to fungal infection
 * deep sulcus sign on a supine radiograph - indicates pneumothorax
 * continuous diaphragm sign - indicates pneumomediastinum
 * ring around the artery sign (around pulmonary artery on lateral chest radiograph) - indicates pneumomediastinum
 * fallen lung sign - indicates a fractured bronchus
 * flat waist sign- indicates left lower lobe collapse
 * gloved finger sign - indicates bronchial impaction, which can be seen in allergic bronchopulmonary aspergillosis
 * Golden S sign - indicates lobar collapse with a central mass, suggesting an obstructing bronchogenic carcinoma in an adult
 * luftsichel sign - indicates upper lobe collapse, potentially due to an obstructing bronchogenic carcinoma in an adult
 * Hampton's hump - indicates a pulmonary infarct
 * silhouette sign - loss of the contour of the heart or diaphragm used to localize a parenchymal process (e.g. a process involving the medial segment of the right middle lobe obscures the right heart border; a lingula process obscures the left  heart border; a basilar segmental lower lobe process obscures the diaphragm)
 * cervicothoracic sign - a mediastinal opacity that projects above the clavicles is retrotracheal and posteriorly situated while an opacity effaced along its superior aspect and projecting at or below the clavicles is situated anteriorly
 * tapered margins sign - a lesion in the chest wall, mediastinum or pleura will have smooth tapered borders and obtuse angles with the chest wall or mediastinum while parenchymal lesions usually form acute angles
 * figure 3 sign - abnormal contour of the descending aorta, indicating coarctation of the aorta
 * fat pad sign or sandwich sign - indicates pericardial effusion on lateral chest radiograph
 * scimitar sign - an abnormal pulmonary vein in venolobar syndrome
 * double density sign - contour projecting over the right side of the heart, indicating enlargement of the left atrium
 * hilum overlay sign and hilum convergence sign -used to distinguish a hilar mass from a non-hilar mass

Be able to define, identify and state the significance of the following on a chest CT:
 * CT angiogram sign - enhancing pulmonary vessels against a background of low attenuation material in the lung
 * halo sign - suggesting invasive pulmonary aspergillosis in a leukemic patient
 * split pleura sign - a sign of empyema


text:
Diagnostic Radiology/Chest Imaging/Interstitial Disease

 * 1) List and identify on a chest radiograph and chest CT four patterns of interstitial lung disease (ILD)
 * 2) Make a specific diagnosis of ILD when supportive findings are present in the history or on radiologic imaging (e.g. dilated esophagus and ILD in scleroderma, enlarged heart and a pacemaker or defibrillator in a patient with prior sternotomy and ILD suggesting amiodarone drug toxicity)
 * 3) Identify Kerley A and B lines on a chest radiograph and explain their etiology
 * 4) Recognize the changes of congestive heart failure on a chest radiograph - enlarged cardiac silhouette, pleural effusions, vascular redistribution, interstitial and/or alveolar edema, Kerley lines
 * 5) Define the terms ìasbestos-related pleural diseaseî and ìasbestosis;î identify each on a chest radiograph and chest CT
 * 6) Describe what a "B" reader is as related to the evaluation of pneumoconiosis
 * 7) Identify honeycombing on a radiograph and high resolution chest CT (HRCT), state the significance of this finding (end-stage lung disease), and list the common causes of honeycomb lung
 * 8) State the radiographic classification of sarcoidosis
 * 9) Recognize progressive massive fibrosis/conglomerate masses secondary to silicosis or coal worker's pneumoconiosis on radiography and chest CT
 * 10) Recognize the typical appearance of irregular lung cysts and/or nodules on chest CT of a patient with Langerhanís cell histiocytosis
 * 11) List four causes of unilateral ILD
 * 12) List three causes of lower lobe predominant ILD
 * 13) List two causes of upper lobe predominant ILD
 * 14) Identify a secondary pulmonary lobule on HRCT
 * 15) Identify lymphangioleiomyomatosis on a chest radiograph and HRCT
 * 16) Identify and give appropriate differential diagnoses when the patterns of septal thickening, perilymphatic nodules, bronchiolar opacities ("tree-in-bud"), air trapping, cysts, and ground glass opacities are seen on HRCT


text:
Diagnostic Radiology/Chest Imaging/Alveolar Disease

 * 1) List four broad categories of acute alveolar lung disease (ALD)
 * 2) List five broad categories of chronic ALD
 * 3) Name three pulmonary-renal syndromes
 * 4) List five of the most common causes of adult respiratory distress syndrome
 * 5) Name four predisposing causes of bronchiolitis obliterans organizing pneumonia (BOOP)
 * 6) Suggest a specific diagnosis of ALD when supportive findings are present in the history or on the chest radiograph (e.g. broken femur and ALD in fat embolization syndrome, ALD and renal failure in a pulmonary-renal syndrome, ALD treated with bronchoalveolar lavage in alveolar proteinosis)
 * 7) Recognize a pattern of peripheral alveolar lung disease on radiography or chest CT and give an appropriate differential diagnosis, including a single most likely diagnosis when supported by associated radiologic findings or clinical information (e.g. peripheral lung disease associated with paratracheal and bilateral hilar adenopathy in an asymptomatic patient with "alveolari" sarcoidosis, peripheral lung disease associated with a markedly elevated blood eosinophil count in a patient with eosinophilic pneumonia, peripheral opacities associated with multiple rib fractures and pneumothorax in a patient with acute chest trauma and pulmonary contusions)


text:
Diagnostic Radiology/Chest Imaging/Other Lung Disease

Atelectasis, Airways and Obstructive Lung Disease

 * 1) Recognize partial or complete atelectasis of the following on a chest radiograph:
 * 2) right upper lobe
 * 3) right middle lobe
 * 4) right lower lobe
 * 5) right upper and middle lobe
 * 6) right middle and lower lobe
 * 7) left upper lobe
 * 8) left lower lobe
 * 9) Recognize complete collapse of the right or left lung on a chest radiograph and list an appropriate differential diagnosis for the etiology of the collapse
 * 10) Distinguish lung collapse from massive pleural effusion on a frontal chest radiograph
 * 11) Name the 4 types of bronchiectasis and identify each type on a chest CT
 * 12) Name 5 common causes of bronchiectasis
 * 13) Recognize the typical appearance of cystic fibrosis on a radiograph and chest CT
 * 14) Name the important things to look for on a chest radiograph when the patient history is "asthma"
 * 15) Define tracheomegaly
 * 16) Recognize tracheal and bronchial stenosis on chest CT and name the most common causes
 * 17) Name the 3 types of pulmonary emphysema and identify each type on a chest CT
 * 18) Recognize alpha-1-antitrypsin deficiency on a chest radiograph and chest CT
 * 19) Recognize Kartagener's syndrome on a chest radiograph and name the 3 components of the syndrome
 * 20) Define the term giant bulla, differentiate giant bulla from pulmonary emphysema and state the role of imaging in patient selection for bullectomy
 * 21) State the imaging findings used to identify surgical candidates for giant bullectomy and for lung volume reduction surgery


text:
Template:Chess diagram small

Chess diagram small

title: Template:Chess diagram small


text:
Art Tutorials/Traditional Media/Supplies and Tools

To create an artwork, you first require supplies and tools. For instance, to create an oil painting, you need something to paint on (often a piece of canvas), something to apply paint (for example, brushes), and oil paint.

Paper
ISO Paper Standards - Getting the right size paper is important. The most common standard is the ISO measurement system. This module details sizes and proportions.

ISO Paper sizes A Series A0 - 1149x841mm A1 - 841x594mm A2 - 594x420mm A3 - 420x297mm A4 - 297x201mm A5 - 210x148mm A6 - 148x105mm A7 - 105x74mm A8 - 74x52mm A9 - 52x37mm A10 - 37x26mm B Series B0 - 1414x1000mm B1 -1000x707mm B2 -707x 500mm B3 - 500x353mm B4 -353x250mm B5 -250x176mm B6 -176x125mm B7 -125x88mm B8 - 88x62mm B9 - 62x44mm B10 - 44x31mm C series C4 - 342x229 mm C5 - 229x114 mm C6 - 162x114 mm Imperial Foolscap - 330x200 mm Crown - 504x384 mm Demy - 564x444 mm Royal - 620x500 mm Elephant - 711x584 mm Imperial - 762x559 mm


text:
Diagnostic Radiology/Neuroradiological Imaging

Neuroradiological imaging is a subspecialty of medical imaging that focuses on visualizing and evaluating the structures of the central nervous system (CNS), which includes the brain and spinal cord. Neuroradiological imaging is crucial for diagnosing and monitoring various neurological disorders, brain and spinal cord injuries, and vascular conditions affecting the CNS. Here are the primary imaging modalities used in neuroradiological imaging:

 * Magnetic Resonance Imaging (MRI):
 * Description: MRI uses strong magnets and radio waves to create detailed images of the brain and spinal cord's soft tissues. It is a versatile imaging modality that can provide multi-planar and high-resolution images.
 * Applications: MRI is used to diagnose a wide range of neurological conditions, including brain tumors, stroke, multiple sclerosis, vascular abnormalities, epilepsy, and spinal cord injuries. Functional MRI (fMRI) can map brain activity.

 * Computed Tomography (CT) of the Brain and Spine:
 * Description: CT scanning uses X-rays to create cross-sectional images of the brain and spinal cord. It is particularly useful for assessing bony structures.
 * Applications: CT is commonly used to diagnose and assess conditions such as head trauma, skull fractures, hemorrhages, and brain lesions. It is also valuable for emergency situations, such as acute strokes and traumatic injuries.

 * Cerebral Angiography:
 * Description: Cerebral angiography involves injecting a contrast dye into the blood vessels of the brain and spinal cord and capturing X-ray images in real-time.
 * Applications: This invasive procedure is used to diagnose and treat vascular conditions, including aneurysms, arteriovenous malformations (AVMs), and narrowing or blockages in the cerebral blood vessels.

 * Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT):
 * Description: PET and SPECT scans use radioactive tracers to assess metabolic and functional activity in the brain.
 * Applications: These techniques are used to evaluate brain function and metabolism, diagnose neurological conditions like Alzheimer's disease, and locate brain tumors.

 * Doppler Ultrasound:
 * Description: Doppler ultrasound uses sound waves to assess blood flow within the blood vessels of the neck and brain.
 * Applications: It is used to diagnose conditions like carotid artery stenosis, which can increase the risk of stroke.

 * Myelography:
 * Description: Myelography involves injecting a contrast dye into the spinal canal and performing X-rays or CT scans to visualize the spinal cord and nerve roots.
 * Applications: Myelography is used to diagnose conditions affecting the spinal cord and nerve roots, such as herniated discs and spinal stenosis.

 * Functional Imaging Techniques:
 * Functional MRI (fMRI): fMRI measures changes in blood flow and oxygenation in the brain, providing insights into brain activity related to tasks and behaviors.
 * Diffusion Tensor Imaging (DTI): DTI is a type of MRI that measures the diffusion of water molecules in neural tissue, allowing visualization of white matter tracts and helping assess brain connectivity.

Neuroradiological imaging is essential for neurologists, neurosurgeons, neuroradiologists, and other healthcare professionals involved in the diagnosis and treatment of neurological disorders. These imaging modalities provide crucial information about brain and spinal cord health and help guide treatment decisions.

Neuroradiology

 * 1) Basic and Advanced Instrumentation
 * 2) Congenital CNS Lesions
 * 3) CNS Infections
 * 4) Neoplasms and Other Masses
 * 5) Trauma
 * 6) White Matter Disease
 * 7) Cerebrovascular Disease
 * 8) Metabolic Disease
 * 9) General Systemic Disorders
 * 10) Hydrocephalus
 * 11) Cognitive Imaging


text:
User:Themiwi

Hi. I'm a graduate student of mechanical engineering at ETHZ (Swiss Federal Institute of Technology). I'm specializing in computational engineering and computational fluid dynamics.

title: User:Themiwi


text:
Diagnostic Radiology/Neuroradiological Anatomy

Neuroradiological anatomy is the study of the structures and components of the central nervous system (CNS), including the brain and spinal cord, using radiological imaging techniques. Radiological imaging plays a crucial role in diagnosing, monitoring, and researching neurological disorders and conditions. Here's an overview of key structures and imaging modalities used in neuroradiological anatomy:

 * Brain Structures:
 * Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, memory, emotion, and voluntary movement. It is divided into two hemispheres.
 * Cerebellum: Located at the back of the brain, the cerebellum coordinates voluntary movements, posture, balance, and motor learning.
 * Brainstem: The brainstem connects the brain to the spinal cord and includes the medulla oblongata, pons, and midbrain. It controls vital functions like breathing, heart rate, and consciousness.
 * Basal Ganglia: Deep within the brain, the basal ganglia plays a role in motor control and learning, as well as emotional and cognitive functions.
 * Limbic System: This network of structures, including the hippocampus and amygdala, is involved in emotions, memory, and motivation.

 * Imaging Modalities in Neuroradiology:
 * Computed Tomography (CT): CT scans use X-rays to create detailed cross-sectional images of the brain and skull. They are often used in emergency situations to detect bleeding, fractures, or masses.
 * Magnetic Resonance Imaging (MRI): MRI provides high-resolution images of the brain's soft tissues, allowing for detailed visualization of structures, including the brain, spinal cord, and blood vessels. Functional MRI (fMRI) can map brain activity.
 * Positron Emission Tomography (PET): PET scans use radioactive tracers to detect metabolic activity in the brain, aiding in the diagnosis and monitoring of neurological conditions, including tumors and Alzheimer's disease.
 * Single Photon Emission Computed Tomography (SPECT): SPECT imaging is used to measure blood flow and brain activity. It can help diagnose conditions like epilepsy and assess blood flow after a stroke.
 * Cerebral Angiography: This procedure involves injecting a contrast dye into blood vessels to visualize blood flow and detect abnormalities like aneurysms, arteriovenous malformations (AVMs), or blockages.

 * Spinal Cord Anatomy:
 * Spinal Cord: The spinal cord is a cylindrical bundle of nerves that extends from the base of the brain down the vertebral canal. It transmits signals between the brain and the rest of the body.
 * Spinal Nerve Roots: These roots, both dorsal (sensory) and ventral (motor), emerge from the spinal cord and carry sensory and motor signals to and from the body.

 * Vascular Anatomy:
 * Circle of Willis: This network of arteries at the base of the brain supplies blood to the cerebral hemispheres. It is important for maintaining blood flow in case of vessel occlusion.
 * Carotid and Vertebral Arteries: The carotid arteries supply blood to the anterior part of the brain, while the vertebral arteries merge to form the basilar artery, which supplies the posterior part of the brain.
 * Dural Sinuses: These venous channels within the dura mater (the brain's outermost membrane) collect blood from the brain and return it to the general circulation.

Neuroradiological anatomy is crucial for diagnosing and understanding neurological disorders such as strokes, tumors, vascular malformations, neurodegenerative diseases, and traumatic brain injuries. Radiologists, neurologists, neurosurgeons, and other healthcare professionals use neuroradiological imaging to make accurate diagnoses and guide treatment decisions.

Brain and Coverings

 * 1) Skull, sutures
 * 2) Major apertures
 * 3) Hemispheres, cortex, gyri, sulci
 * 4) Major fissures
 * 5) Major cisterns
 * 6) Basal ganglia, thalamus, hypothalamus, pituitary gland, pineal gland
 * 7) Pons, cerebellum, cerebellopontine angle
 * 8) Ventricles, choroid plexus
 * 9) Vessels and major branches
 * 10) External carotid artery
 * 11) Common carotid artery
 * 12) Internal carotid artery
 * 13) Circle of Willis
 * 14) Anterior cerebral artery
 * 15) Middle cerebral artery
 * 16) Vertebral, basilar artery
 * 17) Supratentorial veins, dural sinuses
 * 18) Infratentorial veins, dural sinuses

Head and Neck

 * 1) Buccal space
 * 2) Sublingual space
 * 3) Submandibular space
 * 4) Parotid space
 * 5) Parapharyngeal space
 * 6) Poststyloid parapharyngeal (carotid) space
 * 7) Masticator space
 * 8) Retropharyngeal space
 * 9) Perivertebral space
 * 10) Posterior cervical space
 * 11) Pharyngeal mucosal space
 * 12) Oral cavity
 * 13) Oropharynx and nasopharynx
 * 14) Mandible and dental structures
 * 15) Visceral space
 * 16) Larynx and hypopharynx
 * 17) Thyroid
 * 18) Orbit
 * 19) Paranasal sinuses
 * 20) Skull base
 * 21) Anterior
 * 22) Central
 * 23) Posterior
 * 24) Temporal bone

Spine

 * 1) Vertebral bodies
 * 2) Facet joints and transverse processes
 * 3) Lamina and spinous processes
 * 4) Support ligaments
 * 5) Specific characteristics of cervical, thoracic, and lumbar segments
 * 6) Cranio-vertebral and lumbo-sacral junctions
 * 7) Normal stability and motion


text:
Art Tutorials/Traditional Media/Supplies and Tools/ISO Paper

One of the most commonly used standards for paper sizes is the ISO 216 standard. This standard defines paper sizes that are commonly used for comic papers, regular drawing paper, and prints.


text:
Diagnostic Radiology/Musculoskeletal Diagnosis

Musculoskeletal diagnosis involves the assessment and identification of various conditions and disorders affecting the musculoskeletal system, which includes bones, joints, muscles, tendons, ligaments, and other connective tissues. Accurate diagnosis is crucial for planning appropriate treatment and rehabilitation strategies. Here are some key steps and methods used in musculoskeletal diagnosis:

 * Clinical Evaluation:
 * Medical History: Gathering a detailed medical history, including information about the patient's symptoms, the onset of pain or discomfort, previous injuries, and any relevant medical conditions.
 * Physical Examination: A thorough physical examination is conducted to assess the musculoskeletal system. This includes evaluating range of motion, strength, joint stability, and palpating for tenderness or swelling.

 * Imaging Studies:
 * X-rays: X-rays provide detailed images of bones and can help diagnose fractures, joint dislocations, and degenerative conditions like osteoarthritis.
 * Magnetic Resonance Imaging (MRI): MRI is particularly valuable for assessing soft tissues, including muscles, tendons, ligaments, and cartilage. It is used to diagnose conditions like ligament tears, tendon injuries, and joint disorders.
 * Computed Tomography (CT): CT scans can provide detailed images of bones and are useful for evaluating complex fractures, bone tumors, and spinal conditions.
 * Ultrasound (Sonography): Ultrasound is often used to evaluate soft tissues, especially tendons and muscles. It can aid in diagnosing conditions like rotator cuff tears and muscle strains.

 * Laboratory Tests:
 * Blood Tests: Blood tests may be conducted to assess markers of inflammation, infection, or autoimmune diseases that could be affecting the musculoskeletal system.
 * Synovial Fluid Analysis: In cases of joint pain or swelling, synovial fluid analysis may be performed to evaluate the composition of fluid within the joint and identify any underlying conditions like arthritis or infection.

 * Electromyography (EMG) and Nerve Conduction Studies (NCS):
 * EMG: Electromyography assesses the electrical activity of muscles and helps diagnose conditions affecting nerve-muscle interactions, such as peripheral neuropathy or muscle disorders.
 * NCS: Nerve conduction studies evaluate how well nerves are transmitting electrical signals and can be used to diagnose conditions like carpal tunnel syndrome or radiculopathy.

 * Bone Scans and Nuclear Medicine Studies:
 * Bone Scans: Bone scans can detect areas of increased bone turnover, such as those caused by fractures, infections, or bone tumors.
 * Positron Emission Tomography (PET) Scans: PET scans are used to assess metabolic activity within tissues and are valuable for identifying cancerous lesions in bones and soft tissues.

 * Biopsy:
 * Tissue Biopsy: In some cases, a tissue biopsy may be necessary to obtain a sample of abnormal tissue for microscopic examination. This can help diagnose conditions such as bone tumors or inflammatory disorders.

 * Functional Assessment:
 * Functional Testing: Functional assessments, such as gait analysis, strength testing, and range of motion measurements, can provide valuable information about how a musculoskeletal condition is impacting a person's function and mobility.

 * Specialist Consultations:
 * Consulting Specialists: Depending on the suspected condition, patients may be referred to specialists such as orthopedic surgeons, rheumatologists, physical therapists, or sports medicine physicians for further evaluation and management.

An accurate musculoskeletal diagnosis is essential for developing a tailored treatment plan that may include physical therapy, medications, injections, surgical intervention, or other therapies. The choice of diagnostic methods depends on the patient's symptoms, medical history, and the suspected condition, and it often involves a multidisciplinary approach to provide comprehensive care.

Musculoskeletal Radiology

 * 1) Arthritis
 * 2) Lucent Lesions of Bone
 * 3) Sclerotic Lesions of Bone
 * 4) Periosteal Reaction
 * 5) Soft Tissue Calcification
 * 6) Fractures Without Significant Trauma
 * 7) Painful Joint Prosthesis
 * 8) Orthopedic Hardware
 * 9) Scoliosis
 * 10) Osteopenia


text:
Diagnostic Radiology/Chest Diagnosis

Chest diagnosis refers to the process of identifying and evaluating medical conditions and diseases affecting the chest, including the heart, lungs, blood vessels, and surrounding structures. Accurate chest diagnosis is essential for managing a wide range of respiratory, cardiovascular, and thoracic disorders. Here are key steps and methods involved in chest diagnosis:

 * Clinical Evaluation:
 * Medical History: Gathering a comprehensive medical history, including information about symptoms, their onset, duration, and associated factors such as smoking history, occupational exposure, and family history.
 * Physical Examination: A thorough physical examination involves assessing the chest, heart, and lungs. It includes listening to lung sounds, measuring vital signs (e.g., blood pressure, heart rate, respiratory rate), and examining the chest for deformities or masses.

 * Imaging Studies:
 * Chest X-ray: X-rays are used to visualize the chest, including the lungs, heart, ribs, and diaphragm. They are essential for diagnosing lung infections, lung cancer, heart conditions, and fractures.
 * Computed Tomography (CT): CT scans provide detailed cross-sectional images of the chest and are used to evaluate lung nodules, pulmonary embolisms, mediastinal masses, and thoracic anatomy.
 * Magnetic Resonance Imaging (MRI): Chest MRI can be used for detailed evaluation of the heart, blood vessels, and soft tissues within the chest. It is especially valuable for assessing cardiac and vascular conditions.

 * Cardiac Evaluation:
 * Electrocardiogram (ECG or EKG): ECG records the electrical activity of the heart, helping diagnose arrhythmias, ischemia, myocardial infarctions, and other cardiac conditions.
 * Echocardiography: Echocardiography uses ultrasound to create images of the heart's structures and assess cardiac function. It is essential for diagnosing heart valve disorders, cardiomyopathies, and congenital heart defects.

 * Pulmonary Function Tests:
 * Spirometry: Spirometry measures lung function, including lung volumes and airflow, to assess conditions like asthma, chronic obstructive pulmonary disease (COPD), and restrictive lung diseases.

 * Blood Tests:
 * Complete Blood Count (CBC): CBC can reveal signs of infection, anemia, or other hematological abnormalities that may affect chest health.
 * Cardiac Biomarkers: Blood tests can measure cardiac biomarkers such as troponin and creatine kinase (CK-MB) to assess heart damage or myocardial infarction.
 * Arterial Blood Gas (ABG) Analysis: ABG analysis provides information about oxygen and carbon dioxide levels in the blood, helping diagnose respiratory and metabolic disorders.

 * Bronchoscopy and Pulmonary Biopsy:
 * Bronchoscopy: A bronchoscope is used to visualize the airways and obtain samples for biopsy. It is essential for diagnosing lung infections, tumors, and other airway abnormalities.

 * Other Tests and Procedures:
 * Nuclear Medicine Imaging: Techniques like lung perfusion scans and ventilation scans can assess lung function and detect pulmonary embolisms.
 * Vascular Studies: Doppler ultrasound and angiography are used to evaluate blood vessels in the chest and diagnose conditions like deep vein thrombosis (DVT) or aortic aneurysms.

 * Specialist Consultations:
 * Consulting Specialists: Depending on the suspected condition, patients may be referred to specialists such as pulmonologists, cardiologists, cardiothoracic surgeons, or interventional radiologists for further evaluation and management.

Accurate chest diagnosis is essential for guiding appropriate treatment plans, whether they involve medication, surgery, lifestyle changes, or other interventions. The choice of diagnostic methods depends on the patient's symptoms, medical history, and the suspected condition, often requiring a multidisciplinary approach to provide comprehensive care.

Chest Wall, Mediastinum and Pleura

 * 1) Chest Wall Lesions
 * 2) Pleural Masses
 * 3) Pleural Effusions
 * 4) Pleural Thickening and Pleural Calcification
 * 5) Elevated Hemidiaphragm
 * 6) Mediastinal Shift
 * 7) Anterior Mediastinal Mass
 * 8) Middle Mediastnal Mass
 * 9) Posterior Mediastinal Mass
 * 10) Hilar Mass

Increased Pulmonary Opacities

 * 1) Atelectasis
 * 2) Segmental and Lobar Opacities
 * 3) Diffuse Coalescent Opacities
 * 4) Fine Reticular Opacities
 * 5) Coarse Reticular Opacities
 * 6) Diffuse Fine Nodular Disease
 * 7) Multifocal Ill-defined Opacities
 * 8) Multiple Nodules and Masses
 * 9) Solitary Pulmonary Nodule

Loss of Pulmonary Opacity

 * 1) Hyperlucent Lungs
 * 2) Solitary Localized Lucent Defect
 * 3) Multiple Lucent Lesions

title: Diagnostic Radiology/Chest Diagnosis


text:
Talk:Japanese/Lessons/Existence

 * Someone please revise this page!

Untitled

 * 1) The particle が is used without any explanation whatsoever.
 * 2) The order in which the sentences are taught does not make any particular sense.
 * 3) The potentially confusing words 何か and 何も are being used before the student has a chance to absorb the basic structures ～があります and ～がありません.
 * ToothingLummox 21:52, 25 August 2005 (UTC)

 * Good points, but effort should be put into the new lessons, which has a much better (progressive) order of learning things. After the new new lessons are complete, the current lessons will probably be archived until it is made sure that there is nothing important in the archived lessons that are not in the new lesson. - Sik0fewl 22:04, 25 August 2005 (UTC)

 * I think that the older lessons are in far better shape than the new lessons. The new lessons are well on their way to becoming an impenetrable dictionary. I'm afraid that they'll be a nice reference work but not much of a textbook. I considered reorganizing them, but people seem attached to the "deep" format, so I just fixed the newer lessons up a bit. I've adopted a "wait-and-see" attitude towards the new lessons, until I can see how I can usefully contribute to them without stepping on everyone's toes. - ToothingLummox 23:01, 25 August 2005 (UTC)

title: Talk:Japanese/Lessons/Existence


text:
Talk:Using Firefox/Keyboard shortcuts

What I really want to know is how to dissable the complete .com/.net/.org adddress keyboard shortcuts which are completely useless, since they are easy to trigger accidentally (shift-enter especially), and not really at all memorable .. shift==.net? ctrl+Shift== .org ?? what? So the best tip here would be how to disable this crud. Firefox developers are mum on the subject, insisting you're wrong if you want usability over IE compatability, only on your own browser. Suggestions appreciated. --JoshuaRodman
 * http://forums.mozillazine.org/viewtopic.php?t=72994

 * For the shift+enter thing: http://gridley.res.carleton.edu/~morrowa/software/clumsyfingers.html

Need Shortcut for Scrolling within a Page
I guess my Subject line says it: it would be helpful to be able to scroll up or down within a page or move up or down by the amount of the visible window without taking one's hands off the keyboard to touch the mouse. Right now my kluge is to hit / to open a search within the page, then type a period. By tapping F3 I then advance sentence by sentence. Shift F3 to go back up the page. Another (slower) way is to search for spaces with F3.

I think PageUp and PageDown should be programmed to perform as you might think: make the bottom line of the current window into the top line, or vice versa. Right?

Is there something I don't know about? thanks Vincent

title: Talk:Using Firefox/Keyboard shortcuts


text:
Talk:OCR A-Level Physics

wave properties/unifying concepts
I had left these two "modules" out, since despite having seperate exams, wave properties is covered under electrons and photons as far as the specification is concerned. unifying concepts also has a seperate exam, but according to the specification, it is nothing but material covered in the other modules. I will leave those sections there if you feel that enough original content can be added to them. --Krackpipe 22:19, 25 August 2005 (UTC)

Wave properties - this is waves, waves, waves. My recollection of this was that it was almost all done in respect to water surface waves, although I remember reflection and diffraction of light waves, especially Snell's law, critical angle, and application to fibre optics. And sound, vibration in strings, organ pipes. The dual nature of light is covered in Electrons and Photons.

Unifying topics I think would cover how the fundamental principles of physics apply throughout the field - conservation of energy; conservation principles in general; approximate correctness of Newtonian physics at everyday scales of speed, mass, and size; relativistic physics for big and fast; quantum mechanics for the very small.

Ideally each of these fundamental principles would be illustrated by at least two examples of application in different contexts. For instance, how the trajectory of an electron in a television tube has to be calculated relativistically due to the high velocity, yet the rays that it produces on hitting the phosphor screen can be analyzed using classical optics. This demonstrates how sometimes Newtonian physics is a close enough approximation (watching TV), but not always (designing the TV tube).

Those fundamental principles would, of course, already have been covered in their respective sections. --Wrolf 17:28, 26 August 2005 (UTC)

ok, lets keep them, i dont really have any big problems with that. if they dont develop more than a few lines or so, then we could merge them with some of the other sections.--Krackpipe 20:26, 26 August 2005 (UTC)

I'm adding in the Wave Properties section, since as far as I can tell, not everything here is covered in other sections, and I think that sticking to the format of the specification will make life easier for both readers and writers. --Justdig 01:54, 17 April 2006 (UTC)

Orphaned page
G'day, A-level Physics/Edexcel (Salters Horners) seems to be lost - nothing links to it. Could somebody please integrate this back into the book, or alternatively tag it for deletion? thanks, Webaware talk 14:09, 17 March 2008 (UTC)

title: Talk:OCR A-Level Physics


text:
User talk:Wrolf~enwikibooks

A-level Physics
Hi, and thanks for your contributions to the A-level Physics wikibook.

There seems to be some problem with the changes you made to the front page. I have discussed the issues here. It is not a major problem, but we should avoid repeating information that is covered elsewhere.

Thanks --Krackpipe 22:26, 25 August 2005 (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 Wrolf. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Wrolf~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 23:52, 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) 05:39, 19 April 2015 (UTC)

title: User talk:Wrolf~enwikibooks


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

Overview
A boggart is a shapeshifter that usually lurks in dark spaces. It has no definite form, taking the shape of that which is most feared by the person who encounters it. When not in the sight of a person, it is believed to look like a dark blob.

Extended Description
To repel or destroy a boggart, it must be laughed at. The spell Riddikulus can be cast to force the boggart to assume a generally amusing shape of what the caster mentally conceives.

In Harry Potter and the Prisoner of Azkaban, the Boggart appears three times.

 * In Professor Lupin's Defence Against the Dark Arts class, we are introduced to the Boggart and his characteristics, and the fact that this allows us to see people's deepest fears; this also allows us a comical jab at Professor Snape, as Neville produces a simulacrum of Snape dressed in his grandmother's favorite outfit. Lupin does prevent Harry from triggering the Boggart's defence mechanism, which Harry feels is unfair; but Lupin later explains this as being done to prevent a simulacrum of Lord Voldemort from appearing in front of the class. This in particular shows that Lupin is much more aware of the class and its needs and concerns than any of the other Defence Against the Dark Arts teachers that have preceded him in the series.

 * Later, Lupin uses a second Boggart to train Harry in the use of the Patronus charm and its use against Dementors.

 * Either this same Boggart, or a third one, is then used in the final exam for Defence Against the Dark Arts. In this, we see Hermione's insecurity about her grades – her greatest fear is revealed to be "Professor McGonagall – she said I failed everything!" And apparently this is such a great fear that she is unable to invoke Riddikulus against it.

In Harry Potter and the Goblet of Fire, Harry encounters a Boggart in the final task of the Triwizard Tournament. It takes the form of a Dementor upon seeing Harry.

In Harry Potter and the Order of the Phoenix, a Boggart is discovered in a desk in the Headquarters of the Order. It is identified by Alastor Moody using his magical eye, whereupon Mrs. Weasley goes to eliminate it. Ultimately she is unable to, and Remus Lupin, possibly alerted by Mad-Eye Moody, arrives to vanquish it and rescue her.

Analysis
The Boggart has two main purposes in the series: one is to reveal characters' deepest fears, as the Mirror Erised reveals their deepest desires; the other is to give Harry a "dementor" that he can battle, without risking having his soul sucked out. The latter is the most important, as Harry will be called upon to fight Dementors, and must somehow be prepared for that struggle; but their ability to show the greatest fears of the characters will prove useful as well.

The appearance of the Boggart in Harry Potter and the Order of the Phoenix is particularly interesting, not for the fact of the Boggart, but for the illumination it provides. This episode allows Harry to see what Mrs. Weasley's greatest fears are: that her family, or Harry himself, might end up dead. Naturally, Harry is surprised to see that his well-being is so important to Mrs. Weasley, though he does not comment on it at the time. His thoughts are more about his recent upset at having been passed over for Prefectship, and the realization of just how trivial that was relative to the other possible outcomes for the next few years. The author does not explicitly show us the effect this revelation has on Harry in the long term, but it would be safe to say that Harry is heartened by the discovery that there is someone in the world who cares so much about him.

It is somewhat illuminating to note the form Boggarts take when confronted with specific characters in the story. For Ron, a confirmed arachnophobe, it is an Acromantula. Hermione is confronted with the spectre of failing all her courses. Harry, as mentioned, is forced to deal with a Dementor, while Neville faces Professor Snape, and Mrs. Weasley sees, in succession, the death of all her family members and Harry. The Boggart taking the shape of an animated, severed hand for Seamus Finnigan tells us little, but it taking the shape of a full moon when confronted by Lupin would tell us a great deal, if we recognized it as a full moon. It can be interesting to speculate on what other characters would see; Ginny, following the events in the Chamber of Secrets the previous year, might be expected to see herself as a puppet, or to see a puppet master; Fred and George, we suspect, would each see the other, dead, though it is uncertain if a Boggart would ever find one of them alone; and it is a safe assumption that Voldemort would see his own lifeless body.

In connection with this, we note the apparent mindlessness of the Boggart's response. Specifically when confronted by Lupin, the Boggart becomes a small, and pointless, simulacrum of the full moon. It does not change even when Lupin casually brushes it aside, indicating an unawareness that its understanding of Lupin's deepest fear is deeply flawed. This indicates that the Boggart's response is automatic, rather than reasoned, and that the lack of a fear response by the target of the Boggart's illusion is not something that the Boggart can react to.

Questions

 * 1) In Harry Potter and the Prisoner of Azkaban, Professor Lupin says "Nobody knows what a boggart looks like when he is alone," yet in Harry Potter and the Order of the Phoenix, Alastor Moody is able to identify it immediately, before it is released from the desk. What did Moody see with his magical eye?
 * 2) Why does a boggart have the full effect on Harry when it turns into a Dementor but it does not make Lupin a werewolf when it turns into a full moon?
 * 3) What parallels can be drawn between the effects of boggarts and the Mirror of Erised?
 * 4) Our immediate suspicion is that Voldemort, confronted by a boggart, would see his own corpse. Are there other images that could be presented? Support your answer.

Greater Picture
There is some conflicting information about the effects of Boggarts. In particular, the Boggart-as-Dementor that Harry is using to learn the Patronus charm affects him exactly as the true Dementors do, weakening him and allowing him to hear his mother's and father's final minutes. Yet the boggart-as-full-moon that appears in Lupin's Defence Against the Dark Arts class, and the similar effect occurring when Lupin confronts the Boggart in Harry Potter and the Order of the Phoenix, do not cause him to turn into a werewolf.

Uncharacteristically, when Harry encounters the Boggart-as-Dementor in the maze in Harry Potter and the Goblet of Fire, he recognizes it as a Boggart because it trips over its own robes. This is a very uncharacteristic revelation, not something we would expect of a Boggart, and can only be explained by our later understanding that the false Alastor Moody was watching Harry's progress through the maze and eliminating obstacles. Likely he could not eliminate the Boggart, and so made it clumsy to tip Harry off.


text:
Talk:A-level Physics/Forces and Motion/Force, work and power

Specification
From the OCR GCE Physics A specification. Tick with ✔ when you feel each part of the specification has been covered. Try not to add much more than what is in this list as it would not appear in the exam anyway. Use links to wikipedia for more depth in a topic.

 * 1) Understand that the weight of a body may be taken as acting at a single point known as its centre of gravity.
 * 2) Understand a couple as pair of equal parallel forces tending to produce rotation only.
 * 3) Define and use the moment of a force and the torque of a couple.
 * 4) Show an understanding that, when there is no resultant force and no resultant torque, a system is in equilibrium.
 * 5) Apply the principle of moments to solve problems involving forces acting in two dimensions.
 * 6) Define pressure.
 * 7) Recall and use the equation P=F/A
 * 8) Understand the concept of work in terms of the product of force and displacement in the direction of the force.
 * 9) Define the Joule.
 * 10) Recall and use the equation W=Fx, where F is a constant force along the direction of motion.
 * 11) Recall and use equations for kinetic energy Ek=½mv2 and change in gravitational potential energy ∆Ep = mg∆h.
 * 12) Relate power to work done and time taken.
 * 13) Define the Watt
 * 14) Recall and use the equation W=Pt (Work = Power x time).

moving "force"
I think the concept of force should be introduced in Dynamics, because in Kinematics, you are introduced to position, speed, velocity and acceleration without regard to the forces behind the movements, and then in Dynamics, you are introduced to forces of 1N as what accelerates a mass of 1kg at 1m/s^-2.

Force, work and power introduces you to the concept of work done or energy and how power relates to that.

So, basically, the contents of here will be moved to Dynamics --Krackpipe 22:41, 25 August 2005 (UTC)


text:
A-level Physics/Forces and Motion/Dynamics

Dynamics is the study of why objects move, and the effects of forces on moving objects.

Mass
When you are standing on a bus, and the bus starts very quickly, your body seems to be pushed backward, and if the bus stops suddenly, then your body seems to be pushed forwards. Notice that when the bus turns left, you will seem to be pushed to the right, and when the bus turns right, you will seem to be pushed to the left.

Also consider a full shopping cart. If you try to push it from a stationary position, it will take some effort to get it moving. The same is true if you try to stop it when it is moving at a high speed, or try to turn it left or right.

In both cases, an object with mass is opposing a change in motion. In the first case, it is your body that tries to stay moving as it was before the change. Your body also tries to stay in a straight line when the bus turns, although it appears to be moving to the side. What is really happening is that your body is still moving straight and the bus turns in the opposite direction. The shopping cart exhibits the same behaiviour. When it is stationary, it tries to stay stationary, and when you try to stop it moving, it will try to continue. Your body and the cart both have mass.

From this, we can define a property of mass:

Mass will resist changes in motion.

This says that any object with mass will resist any change in motion. Objects with greater mass will resist change in motion more than objects with less mass. It is like having the shopping cart only half full and finding that it is much easier to change its movement. This is Newton's first law of motion: An object at rest will remain at rest unless acted upon by an outside force. Conversely: An object in motion will remain in motion unless acted upon by an outside force.

In the SI system, the unit of mass is the kilogram (kg).

Force
We all have an innate understanding of forces. To put quite simply, a force involves a push or a pull. Exerting a force on an object will cause that object to accelerate.

Try pushing your finger against a wall. By doing this, you are said to exert a force on the wall. You will feel the wall 'pushing' back on you. The wall is said to exert a force on you. The force you exert on the wall always equals the force with which the wall exerts on you (Newton's Third Law).* Note that the forces are acting on different bodies. Because the wall is heavy, the force you exert on it does not move the wall noticeably. However, being much lighter, you will be probably be moved by the force that the wall exerts on you. Try it!

A force can be applied to an object in different directions. Force is said to be a vector quantity.

Force and Acceleration
Exerting a force on an object causes the object to accelerate. The same force applied on objects of different masses causes different accelerations in each object. We observe that a force applied on a light object causes greater acceleration than the same force applied on a heavier object. We also observe that the acceleration of an object is proportional to the force exerted on it.

This is summarized by the formula F = kma, where F=force, k=some constant, m=mass and a=acceleration.

Defining the Newton
In the SI unit system, force is measured in Newtons. One Newton is the force required to accelerate a mass of 1 kg at $$1 \rm{m s^{-2}}$$. Therefore, we have defined the unit of force in such a way that the value of k in F = kma is 1, thereby reducing the equation to F = ma.

1 N = 100000 dynes = 0.101971621298 kgforce = 0.2248089431 lbforce

1 dyne = 1E-5 Newtons,  1 kgforce=9.80665 Newtons,  and 1 lbforce=4.44822161526 Newtons

Weight
The weight of an object is defined as the gravitational force acting on the object, and is dependent on the mass of the body. Note that the acceleration due to gravity (or acceleration of free-fall, usually denoted by g) is taken as the constant $$9.81 \rm{m s^{-2}}$$ for all bodies, although it varies slightly from place to place. The direction of that force (weight) is always toward the center of this planet. We can calculate the weight of an object from its mass by the equation W = mg, where W=weight, m=mass and g=acceleration of free fall. In rough terms, an apple weighs approximately one Newton.

 * Newton's third law: For every action, there is an equal and opposite reaction.

Motion of particles through fluids
Mechanics of particle motion.

There are three forces acting on particles in motion through a fluid;

1) The external force (gravitational or otherwise);

2) The drag force (apparent when there is relative motion between a particle and a fluid);

3) The buoyant force (acting parallel to the external force, but in the opposite direction).

Density
$$Density = \frac {Mass} {Volume}$$

Viscosity
Viscosity of a fluid is a measure of its resistance to flow. Objects drag fluid along near its surface. The faster the object moves, the bigger the viscous drag.


text:
Cookbook:Salt Cod and Potato Casserole (Bacalhau à Zé do Pipo)

Bacalhau à zé do pipo is a traditional Portuguese cod dish. It can be confused with various other Portuguese dried/salted codfish recipes.

Mashed potatoes

 * 500 g (18 oz / 1.1 lbs) white or golden potatoes
 * Milk (optional)
 * Black pepper (optional)
 * Lemon juice (optional)
 * Eggs (optional)
 * 100 g (3.5 oz) black olives
 * Salt

Assembly

 * 400 g (14 oz / 0.9 lb) salted dried cod
 * Milk
 * Salt
 * White pepper
 * 200 g (7 oz / ½ lb) of onions
 * 5 g minced garlic
 * Olive oil
 * Mayonnaise

Mashed potatoes

 * 1) Roast the potatoes in the oven until tender. Cool slightly.
 * 2) Mash the potatoes, mixing in the milk, pepper, lemon juice, and eggs, if using.
 * 3) Mix in the olives. Season with salt to taste.

Assembly

 * 1) Prepare the cod by leaving it for 24 hours in water, changing the water once or twice.
 * 2) After the 24 hour period is up, put the cod in a pot with milk.
 * 3) Boil the cod until slightly cooked, then season with salt and pepper. The milk will make the fish soft.
 * 4) Slice the onions into rings, and fry in pan with garlic and lots of olive oil until slightly browned.
 * 5) Preheat oven to 220°C (425°F).
 * 6) Place the cod in the center of a casserole or baking dish.
 * 7) Surround the fish with 500 g of the mashed potatoes, then top it with the fried onion.
 * 8) Cover the onion with a thick layer of mayonnaise, and sprinkle bread crumbs all over.
 * 9) Bake until toasted on top.
 * 10) Serve with a green wine from the north of Portugal.


text:
User:Strongbad/North American Football/Overview

In a game of football, each team is allowed to have a certain number of players, and each team cannot have more than eleven players on the field whenever the ball is in play. The players have different jobs, which are explained in more detail in their respective chapters. In most games, one team(the home team) hosts the game and is said to have home field advantage. The other team is the visiting or away team. The game normally takes place at the home team's stadium, but in special cases, the stadium may be different.

At the beginning of the game, a coin is flipped and the visiting team calls heads or tails while the coin is in the air. Whichever team wins the toss gets to choose whether to choose between kicking and receiving or the choice of which goal to defend, and the loser is stuck with the other choice (which is usually the choice of which goal to defend). The kicking team kicks the ball to the other team, which tries to get as close to the opponent's goal line as possible before being tackled. (Goal lines, end zones, and things like that are explained in the football field chapter.) Once the receiver is tackled, the team in possession of the ball brings out its offense and the opponent brings out its defense.

The offense tries to get to the defense's end zone on each of its drives. On the first play, the situation is described as "first and ten," which means that it is first down and the offense must gain at least ten yards on the play to get another first down. The yard line that the ball lies on before the center snaps it is called the line of scrimmage, which is adjusted whenever the offense gains or loses yards. The yard line that the offense must cross to gain a first down is designated using a first down marker, which is adjusted whenever a new first down is gained. The number of yards gained or lost on a play is determined by three things:

 * 1.Running yardage
 * 2.Passing yardage
 * 3.Applicable penalties

If the offense is stopped behind the first down marker, the down normally increases by one until fourth down, where the offense may go for a first down, punt, or attempt a field goal. If the offense reaches the defense's end zone, it can kick the ball for an extra point or attempt a two point conversion. After the offense scores, it kicks the ball to the defense, who gains possession of the ball, and the cycle begins again. After each quarter, the teams exchange end zones and the field positions and ball location are adjusted accordingly. At the beginning of the second half, the team who kicked at the beginning of the game receives the ball.

If the fourth quarter ends in a tie, the game goes into overtime, and the way overtime works varies from game to game. In professional football, the first team to break the tie wins the game, while American college football gives the non-scoring team one drive to win or tie the game again. As such, college overtime tends to be longer than NFL overtime.

Note: Although the most popular part of football is still the game itself, cheerleaders have become an important part of the football experience, even at the college level. Some cheerleaders also take part in non-sports-related activities, like calendar shoots.


text:
Talk:Latin/Authors

Untitled
Hello! I am sorry to bother you... I am looking for help for a simple, simple thing, but can't find it around, and I was wondering if you could help me.. I am opening a business as a behaviour consultant. I would like to name that business the equivalent of "new behavior" in Latin I believe the appropriate new would be "novo" but i'll be damn if I can find the correct word for behaviour, let alone conjugate it. Any chance you can help me out? Thanks... sebastien tremblay pls email me the answer.... supernova_6969@hotmail.com

title: Talk:Latin/Authors


text:
User:Strongbad/North American Football/The Football Season

In any sport, it's good to know how the seasons work. This chapter describes what happens during a typical football season.

NFL season
Each season in the NFL begins with a preseason. The preseason lasts around four weeks, and most of the teams have to play four games. Some teams play five games during the preseason. These games don't count toward the teams' standings and allow the players to get warmed up.

After the preseason, each team plays a regular season. Normally, every team plays 16 games and has one bye week, which means that it doesn't play during that week. The win-loss-tie record is used to compute a team's standing, where a tie is worth half a win. The teams that do the best in their divisions along with the best two teams among the remaining twelve in each conference(the wild card teams) advance to the playoffs.

The playoff teams are given seeds based on their performance, where the divisional champions have lower seeds than the wild card teams and the best teams in these groups have the lowest seeds in that group. In each game, the lower seed has home field advantage. The highest seeds play the first round, which is called the Wild Card Weekend, and each wild card team must play against a division champion(#3 against #6, #4 against #5). The four remaining teams compete in a single elimination tournament, and the last team in each conference moves on to the Super Bowl. The Pro Bowl is the other postseason bowl game, and the two conferences pick the best players for each position to compete in this game.


text:
User:Strongbad/North American Football/Teams

This chapter lists teams that participate in football.

National Football League teams
This is a list of all NFL teams, alphabetized by nickname. Also, the division that the team plays in is listed. Clicking on a team name leads to its official website.

 * San Francisco 49ers(NFC West)
 * Chicago Bears(NFC North)
 * Cincinnati Bengals(AFC North)
 * Buffalo Bills(AFC East)
 * Denver Broncos(AFC West)
 * Cleveland Browns(AFC North)
 * Tampa Bay Buccaneers(NFC South)
 * Arizona Cardinals(NFC West)
 * San Diego Chargers(AFC West)
 * Kansas City Chiefs(AFC West)
 * Indianapolis Colts(AFC South)
 * Dallas Cowboys(NFC East)
 * Miami Dolphins(AFC East)
 * Philadelphia Eagles(NFC East)
 * Atlanta Falcons(NFC South)
 * New York Giants(NFC East)
 * Jacksonville Jaguars(AFC South)
 * New York Jets(AFC East)
 * Detroit Lions(NFC North)
 * Green Bay Packers(NFC North)
 * Carolina Panthers(NFC South)
 * New England Patriots(AFC East)
 * Oakland Raiders(AFC West)
 * St. Louis Rams(NFC West)
 * Baltimore Ravens(AFC North)
 * Washington Redskins(NFC East)
 * New Orleans Saints(NFC South)
 * Seattle Seahawks(NFC West)
 * Pittsburgh Steelers(AFC North)
 * Houston Texans(AFC South)
 * Tennessee Titans(AFC South)
 * Minnesota Vikings(NFC North)

NCAA Football Teams
This is a list of American college-level teams in Division I-A, alphabetized by nickname and then by geographical region.

 * Air Force
 * Akron
 * Arizona
 * Arizona State
 * Arkansas State
 * Army
 * Ball State
 * Baylor
 * Boise State
 * Bowling Green
 * Brigham Young
 * Buffalo
 * California
 * Central Michigan
 * Cincinnati
 * Colorado
 * East Carolina
 * Eastern Michigan
 * Florida Atlantic
 * Florida International
 * Fresno State
 * Houston
 * Idaho
 * Illinois
 * Iowa
 * Iowa State
 * Kansas State
 * Kent State
 * Louisiana Tech
 * Louisiana-Monroe
 * Louisville
 * Marshall
 * Maryland
 * Memphis
 * Miami(Ohio)
 * Michigan
 * Michigan State
 * Minnesota
 * Missouri
 * Navy
 * Nevada
 * New Mexico
 * New Mexico State
 * North Carolina State
 * North Texas
 * Northern Illinois
 * Northwestern
 * Ohio
 * Oklahoma State
 * Oregon State
 * Penn State
 * Pittsburgh
 * Purdue
 * Rice
 * Rutgers
 * San Diego State
 * San Jose State
 * South Carolina
 * South Florida
 * Southern Methodist
 * Southern Miss
 * Syracuse
 * Temple
 * Texas Christian University
 * Texas Tech
 * Toledo
 * Troy
 * Tulane
 * Tulsa
 * University of Alabama at Birmingham
 * University of Central Florida
 * University of Nevada,Las Vegas
 * University of Texas at El Paso
 * Utah
 * Utah State
 * Wake Forest
 * Washington
 * Washington State
 * Western Michigan
 * Wisconsin
 * Texas A&M Aggies
 * Duke Blue Devils
 * Middle Tennessee State Blue Raiders
 * UCLA Bruins
 * Ohio State Buckeyes
 * Colorado State Buffalos
 * Georgia Bulldogs
 * Mississippi State Bulldogs
 * Stanford Cardinals
 * Virginia Cavaliers
 * Vanderbilt Commodores
 * Nebraska Corn Huskers
 * Wyoming Cowboys
 * Alabama Crimson Tide
 * Oregon Ducks
 * Boston College Eagles
 * Notre Dame Fighting Irish
 * Florida Gators
 * Virginia Tech Hokies
 * Indiana Hoosiers
 * Miami Hurricanes
 * Connecticut Huskies
 * Kansas Jayhawks
 * Texas Longhorns
 * West Virginia Pioneers
 * Louisiana-Lafayette Ragin' Cajuns
 * Hawaii Rainbows
 * Arkansas Razorbacks
 * Mississippi Rebels
 * Florida State Seminoles
 * Oklahoma Sooners
 * North Carolina Tar Heels
 * Auburn Tigers
 * Clemson Tigers
 * Louisiana State University Tigers
 * University of Southern California Trojans
 * Tennessee Volunteers
 * Kentucky Wildcats
 * Georgia Tech Yellow Jackets

NFL Europe Teams
This is a list of NFL Europe teams, alphabetized by nickname.

 * Amsterdam Admirals
 * Cologne Centurions
 * Rhein Fire
 * Frankfurt Galaxy
 * Hamburg Sea Devils
 * Berlin Thunder


text:
C++ Programming/Programming Languages/C++/Code/Compiler

The Compiler
A compiler is a program that translates a computer program written in one computer language (the source code) into an equivalent program written in the computer's native machine language. This process of translation, that includes several distinct steps is called compilation. Since the compiler is a program, itself written in a computer language, the situation may seem a paradox akin to the chicken and egg dilemma. A compiler may not be created with the resulting compilable language but with a previous available language or even in machine code.

Compilation
The compilation output of a compiler is the result from translating or compiling a program. The most important part of the output is saved to a file called an object file, it consists of the transformation of source files into object files.

The instructions of this compiled program can then be run (executed) by the computer if the object file is in an executable format. However, there are additional steps that are required for a compilation: preprocessing and linking.

Compile-time
Defines the time and operations performed by a compiler (i.e., compile-time operations) during a build (creation) of a program (executable or not). Most of the uses of "static" in the C++ language are directly related to compile-time information.

The operations performed at compile time usually include lexical analysis, syntax analysis, various kinds of semantic analysis (e.g., type checks, some of the type casts, and instantiation of template) and code generation.

The definition of a programming language will specify compile time requirements that source code must meet to be successfully compiled.

Compile time occurs before link time (when the output of one or more compiled files are joined together) and runtime (when a program is executed). In some programming languages it may be necessary for some compilation and linking to occur at runtime.

Run-time, or execution time, starts at the moment the program starts to execute and end as it exits. At this stage the compiler is irrelevant and has no control. This is the most important location in regards to optimizations (a program will only compile once but run many times) and debugging (tracing and interaction will only be possible at this stage). But it is also in run-time that some of the type casting may occur and that Run-Time Type Information (RTTI) has relevance. The concept of runtime will be mentioned again when relevant.
 * Run-time

Lexical analysis
This is alternatively known as scanning or tokenisation. It happens before syntax analysis and converts the code into tokens, which are the parts of the code that the program will actually use. The source code as expressed as characters (arranged on lines) into a sequence of special tokens for each reserved keyword, and tokens for data types and identifiers and values. The lexical analyzer is the part of the compiler which removes whitespace and other non compilable characters from the source code. It uses whitespace to separate different tokens, and ignores the whitespace.

To give a simple illustration of the process:

Depending on the lexical rules used it might be tokenized as:

1 = string "int" 2 = string "main" 3 = opening parenthesis 4 = closing parenthesis 5 = opening brace 6 = string "std" 7 = namespace operator 8 = string "cout" 9 = << operator 10 = string ""hello world"" 11 = string "endl" 12 = semicolon 13 = string "return" 14 = number 0 15 = closing brace

And so for this program the lexical analyzer might send something like:

1 2 3 4 5 6 7 8 9 10 9 6 7 11 12 13 14 12 15

To the syntactical analyzer, which is talked about next, to be parsed. It is easier for the syntactical analyzer to apply the rules of the language when it can work with numerical values and can distinguish between language syntax (such as the semicolon) and everything else, and knows what data type each thing has.

Syntax analysis
This step (also called sometimes syntax checking) ensures that the code is valid and will sequence into an executable program. The syntactical analyzer applies rules to the code, checking to make sure that each opening brace has a corresponding closing brace, and that each declaration has a type, and that the type exists, and that.... syntax analysis is more complicated than lexical analysis =).

As an example:

 * The syntax analyzer would first look at the string "int", check it against defined keywords, and find that it is a type for integers.
 * The analyzer would then look at the next token as an identifier, and check to make sure that it has used a valid identifier name.
 * It would then look at the next token. Because it is an opening parenthesis it will treat "main" as a function, instead of a declaration of a variable if it found a semicolon or the initialization of an integer variable if it found an equals sign.
 * After the opening parenthesis it would find a closing parenthesis, meaning that the function has 0 parameters.
 * Then it would look at the next token and see it was an opening brace, so it would think that this was the implementation of the function main, instead of a declaration of main if the next token had been a semicolon, even though you can not declare main in c++. It would probably create a counter also to keep track of the level of the statement blocks to make sure the braces were in pairs. *After that it would look at the next token, and probably not do anything with it, but then it would see the :: operator, and check that "std" was a valid.
 * Then it would see the next token "cout" as the name of an identifier in the "std", and see that it was a template.
 * The analyzer would see the << operator next, and so would check that the << operator could be used with cout, and also that the next token could be used with the << operator.
 * The same thing would happen with the next token after the ""hello world"" token. Then it would get to the "std" token again, look past it to see the :: operator token and check that the  existed again, then check to see if "endl" was in the.
 * Then it would see the semicolon and so it would see that as the end of the statement.
 * Next it would see the keyword, and then expect an integer value as the next token because main returns an integer, and it would find 0, which is an integer.
 * Then the next symbol is a semicolon so that is the end of the statement.
 * The next token is a closing brace so that is the end of the function. And there are no more tokens, so if the syntax analyzer did not find any errors with the code, it would send the tokens to the compiler so that the program could be converted to machine language.

This is a simple view of syntax analysis, and real syntax analyzers do not really work this way, but the idea is the same.

Here are some keywords which the syntax analyzer will look for to make sure you are not using any of these as identifier names, or to know what type you are defining your variables as or what function you are using which is included in the C++ language.

Compile speed
There are several factors that dictate how fast a compilation proceeds, like:

 * Hardware
 * Resources (Slow CPU, low memory and even a slow HDD can have an influence)

 * Software
 * The compiler itself, new is always better, but may depend on how portable you want the project to be.
 * The design selected for the program (structure of object dependencies, includes) will also factor in.

Experience tells that most likely if you are suffering from slow compile times, the program you are trying to compile is poorly designed, take the time to structure your own code to minimize re-compilation after changes. Large projects will always compile slower. Use pre-compiled headers and external header guards. We will discuss ways to reduce compile time in the Optimization Section of this book.


text:
User:Tiria~enwikibooks

About Me
Name: Patricia Robinson

Birthdate: September 9

More information can be found on my profile at Wikipedia. Most of my contributions to this project are for that particular section. On Wikibooks, I occasionally edit some of the scenes from the website's text of Macbeth for punctuation and/or accuracy, if needed.

title: User:Tiria~enwikibooks


text:
Chess Opening Theory/ECO volume A

=ECO index: A00--A99=
 * A00: Uncommon Openings: 1. g3 (Benko Opening), 1. Nc3 (Sleipner Opening), 1. a3 (Anderssen's Opening), 1. b4 (Polish Opening), 1. g4 (Grob's Attack), 1. h3 (Basmanic Defence), 1. c3 (Saragossa Opening), 1. d3 (Mieses Opening), 1. e3 (French Attack), 1. h4 (Desprez Opening), 1. a4 (Ware Opening), 1. Nh3 (Amar Opening), 1. Na3 (Durkin's Attack), 1. f3 (Gedult's Opening), 1. e3 e5 2. e4 (King's Isa Reverse)
 * A01: Nimzowitsch-Larsen Attack: 1. b3
 * A02: Bird's Opening: 1. f4
 * A03: Bird's Opening: 1. f4 d5
 * A04: Reti Opening: 1. Nf3
 * A05: Reti Opening: 1. Nf3 Nf6
 * A06: Reti Opening: 1. Nf3 d5
 * A07: King's Indian Attack: 1. Nf3 d5 2. g3
 * A08: King's Indian Attack: 1. Nf3 d5 2. g3 c5 3. Bg2
 * A09: Reti Opening: 1. Nf3 d5 2. c4
 * A10: English: 1. c4
 * A11: English, Anglo-Slav System: 1. c4 c6
 * A12: English with b3: 1. c4 c6 2. Nf3 d5 3. b3
 * A13: English: 1. c4 e6
 * A14: English: 1. c4 e6 2. Nf3 d5 3. g3 Nf6 4. Bg2 Be7 5. O-O
 * A15: English: 1. c4 Nf6
 * A16: English: 1. c4 Nf6 2. Nc3
 * A17: English: 1. c4 Nf6 2. Nc3 e6
 * A18: English, Mikenas-Carls: 1. c4 Nf6 2. Nc3 e6 3. e4
 * A19: English, Mikenas-Carls, Sicilian Variation: 1. c4 Nf6 2. Nc3 e6 3. e4 c5
 * A20: English: 1. c4 e5
 * A21: English: 1. c4 e5 2. Nc3
 * A22: English: 1. c4 e5 2. Nc3 Nf6
 * A23: English, Bremen System, Keres Variation: 1. c4 e5 2. Nc3 Nf6 3. g3 c6
 * A24: English, Bremen System with ...g6: 1. c4 e5 2. Nc3 Nf6 3. g3 g6
 * A25: English: 1. c4 e5 2. Nc3 Nc6
 * A26: English: 1. c4 e5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. d3 d6
 * A27: English, Three Knights System: 1. c4 e5 2. Nc3 Nc6 3. Nf3
 * A28: English: 1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6
 * A29: English, Four Knights, Kingside Fianchetto: 1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 g3
 * A30: English, Symmetrical: 1. c4 c5
 * A31: English, Symmetrical, Benoni Formation: 1. c4 c5 2. Nf3 Nf6 3. d4
 * A32: English, Symmetrical Variation: 1. c4 c5 2. Nf3 Nf6 3. d4 cxd4 4. Nxd4 e6
 * A33: English, Symmetrical: 1. c4 c5 2. Nf3 Nf6 3. d4 cxd4 4. Nxd4 e6 5. Nc3 Nc6
 * A34: English, Symmetrical: 1. c4 c5 2. Nc3
 * A35: English, Symmetrical: 1. c4 c5 2. Nc3 Nc6
 * A36: English, Symmetrical: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7
 * A37: English, Symmetrical: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. Nf3
 * A38: English, Symmetrical: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. Nf3 Nf6
 * A39: English, Symmetrical: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. Nf3 Nf6 6. O-O O-O 7. d4
 * A40: Unusual Black responses to 1. d4: 1...e5 (Englund Gambit), 1...b5 (Polish Defence), 1...Nc6 (Nimzowitsch Defence), 1...g6 (Modern Defence without 2. e4), 1...e6 (French Indian Defence).
 * A41: Tartakower System: 1. d4 d6
 * A42: Tartakower System with 2. c4: 1. d4 d6 2.c4
 * A43: Various Benonis: 1. d4 c5
 * A44: Old Benoni: 1. d4 c5 2. d5 e5
 * A44: Semi-Benoni: 1. d4 c5 2. d5 e5 3. e4 d6
 * A45: Unusual Indian Openings: 1. d4 Nf6
 * A45: Trompowsky Attack: 1. d4 Nf6 2. Bg5
 * A46: Unusual Indian Openings with 2. Nf3: 1. d4 Nf6 2. Nf3
 * A47: Unusual Indian Openings with 2. Nf3: 1. d4 Nf6 2. Nf3 b6
 * A48: Torre Attack with 2...e6: 1. d4 Nf6 2. Nf3 e6 3. Bg5
 * A48: Torre Attack with 2...g6: 1. d4 Nf6 2. Nf3 g6 3. Bg5
 * A48: London System: 1. d4 Nf6 2. Nf3 e6 3. Bf4
 * A49: Fianchetto Variation: 1. d4 Nf6 2. Nf3 e6 3. g3
 * A50: Black Knights' Tango: 1. d4 Nf6 2. c4 Nc6
 * A51: Budapest Gambit Declined and Unusual Lines: 1. d4 Nf6 2. c4 e5
 * A52: Budapest Gambit Main Lines: 1. d4 Nf6 2. c4 e5 3. dxe5 Ng4
 * A53: Old Indian Defence: 1. d4 Nf6 2. c4 d6
 * A54: Old Indian Defence main lines: 1. d4 Nf6 2. c4 d6 3. Nc3 e5
 * A55: Old Indian Defence main lines: 1. d4 Nf6 2. c4 d6 3. Nc3 e5 4. Nf3
 * A56: Czech Benoni: 1. d4 Nf6 2. c4 c5 3. d5
 * A57: Benko/Volga Gambit sidelines: 1. d4 Nf6 2. c4 c5 3. d5 b5
 * A58: Benko/Volga Gambit Accepted: 1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5
 * A59: Benko/Volga Gambit Accepted (White castles by hand): 1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. bxa6 Bxa6 6. Nc3 d6 7. e4
 * A60: Modern Benoni and early divergences: 1. d4 Nf6 2. c4 c5 3. d5 e6
 * A61: Modern Benoni without early e4: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6
 * A62: Modern Benoni, Fianchetto Variation without early ...Nbd7: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. g3
 * A63: Modern Benoni, Fianchetto Variation sidelines: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. g3 Bg7 8. Bg2 O-O
 * A64: Modern Benoni, Fianchetto Variation main line: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. g3 Bg7 8. Bg2 O-O 9. O-O Re8 10. Nd2 Nbd7
 * A65: Modern Benoni, sidelines with early e4: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4
 * A66: Modern Benoni, Mikenas Attack: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. f4 Bg7 8. e5
 * A67: Modern Benoni, Taimanov Variation: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. f4 Bg7 8. Bb5+
 * A68: Modern Benoni, Four Pawns Attack without 9...Re8: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. f4 Bg7 8. Nf3 O-O 9. Bd3
 * A69: Modern Benoni, Four Pawns Attack with 9...Re8: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. f4 Bg7 8. Nf3 O-O 9. Re8
 * A70: Modern Benoni, 7.Nf3: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3
 * A71: Modern Benoni, 7.Nf3 Bg7 8.Bg5 without Be2: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Bg5
 * A72: Modern Benoni, Classical Variation with Bg5: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. Bg5
 * A73: Modern Benoni, Classical Variation and unusual Black 9th moves: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O
 * A74: Modern Benoni, Classical Variation with 9...a6: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O a6
 * A75: Modern Benoni, Classical Variation main line: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O a6 10. a4 Bg4
 * A76: Modern Benoni, Classical Variation with 9...Re8 10.Qc2: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O Re8 10. Qc2
 * A77: Modern Benoni, Classical Variation with 9...Re8 10.Nd2: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O Re8 10. Nd2
 * A78: Modern Benoni, Classical Variation with 10...Na6: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O Re8 10. Nd2 Na6
 * A79: Modern Benoni, Classical Variation with 10...Na6 11.f3: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Nf3 Bg7 8. Be2 O-O 9. O-O Re8 10. Nd2 Na6 11. f3
 * A80: Dutch Defence and unusual White second moves: 1. d4 f5
 * A81: Dutch Defence with 2.g3: 1. d4 f5 2. g3
 * A82: Dutch Defence, Staunton Gambit: 1. d4 f5 2. e4
 * A83: Dutch Defence, Staunton Gambit with 3.Nc3 Nf6 4.Bg5: 1. d4 f5 2. e4 fxe4 3. Nc3 Nf6 4. Bg5
 * A84: Dutch Defence, 2.c4: 1. d4 f5 2. c4
 * A85: Dutch Defence, 2.c4 Nf6 3.Nc3: 1. d4 f5 2. c4 Nf6 3. Nc3
 * A86: Dutch Defence, Leningrad Variation sidelines: 1. d4 f5 2. c4 Nf6 3. g3
 * A87: Dutch Defence, Leningrad Variation with 5.Nf3: 1. d4 f5 2. c4 Nf6 3. g3 g6 4. Bg2 Bg7 5. Nf3
 * A88: Dutch Defence, Leningrad Variation main line 7...c6: 1. d4 f5 2. c4 Nf6 3. g3 g6 4. Bg2 Bg7 5. Nf3 O-O 6. O-O d6 7. Nc3 c6
 * A89: Dutch Defence, Leningrad Variation main line 7...Nc6: 1. d4 f5 2. c4 Nf6 3. g3 g6 4. Bg2 Bg7 5. Nf3 O-O 6. O-O d6 7. Nc3 Nc6
 * A90: Dutch Defence sidelines and Stonewall: 1. d4 f5 2. c4 Nf6 3. g3 e6
 * A91: Dutch Defence, Classical Variation sidelines: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7
 * A92: Dutch Defence, Classical Stonewall with ...Be7 and early deviations: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3
 * A93: Dutch Defence, Classical Stonewall with 7.b3: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 d5 6. O-O O-O 7. b3
 * A94: Dutch Defence, Classical Stonewall with 7.b3 c6 8.Ba3: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 d5 6. O-O O-O 7. b3 c6 8. Ba3
 * A95: Dutch Defence, Classical Stonewall with 7.Nc3 c6: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 d5 6. O-O O-O 7. Nc3 c6
 * A96: Dutch Defence, Ilyin-Genevsky Variation: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 O-O 6. O-O d6
 * A97: Dutch Defence, Ilyin-Genevsky Variation: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 O-O 6. O-O d6 7. Nc3 Qe8
 * A98: Dutch Defence, Ilyin-Genevsky Variation with 8.Qc2: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 O-O 6. O-O d6 7. Nc3 Qe8 8. Qc2
 * A99: Dutch Defence, Ilyin-Genevsky Variation with 8.b3: 1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7 5. Nf3 O-O 6. O-O d6 7. Nc3 Qe8 8. b3

ECO volumes

 * ECO volume A A00-A99
 * ECO volume B B00-B99
 * ECO volume C C00-C99
 * ECO volume D D00-D99
 * ECO volume E E00-E99

title: Chess Opening Theory/ECO volume A


text:
Cookbook:1-2 Chocolate Cake

| Cake

1-2 chocolate cake is a simple, fairly easy chocolate cake recipe.

Ingredients

 * ⅓ cup (80 ml) vegetable oil
 * 2 ounces (55 g) unsweetened chocolate
 * 1 cup granulated sugar (or ½ cup)
 * 1 egg
 * 1¼ cups (300 g) whole wheat flour
 * ½ teaspoon salt
 * ½ teaspoon baking soda
 * ½ teaspoon vanilla extract
 * ¾ cup (180 ml) water
 * ¾ cup (180 g) semi-sweet chocolate pieces (such as chocolate chips)
 * ½ cup (120 g) chopped nuts
 * 4 ounces (115 g) cream cheese or sour cream (optional)

Procedure

 * 1) Put the oil and chocolate in an 8-inch (20 cm) square pan and set it in 350 °F (180 °C) oven just until the chocolate melts. Add sour cream or cream cheese if desired.
 * 2) Add remaining ingredients, except chocolate chips and nuts, to the pan.
 * 3) Beat with a fork until smooth and creamy (about 2 minutes).
 * 4) Scrape the sides of the pan, and spread the batter evenly in the pan.
 * 5) Sprinkle with chocolate chips and nuts. Optionally, cut the chocolate chips and nuts into the batter to some extent.
 * 6) Bake at 350 °F (180 °C) for 30 to 40 minutes, until a toothpick stuck in the center comes out clean.
 * 7) Cool in pan; eat hot or cooled.

title: Cookbook:1-2 Chocolate Cake


text:
Cookbook:Baked Oatmeal

Baked oatmeal is excellent as a breakfast in its less-sweet variation or a snack. The first variation presented here may taste more like a dessert than a breakfast food, although is no less delicious for that; try them both and see which you prefer.

Ingredients

 * 3 cups (720 g) quick-cooking oats
 * 1 cup (240 g) brown sugar
 * 2 teaspoons baking powder
 * 1 teaspoon ground cinnamon
 * 1 teaspoon salt
 * 1 cup (240 ml) milk
 * ½ cup (120 g) butter (melted)
 * 2 eggs

Procedure

 * 1) Mix the ingredients and pour them into a 9-inch (20 cm) baking pan. They can also be mixed in the pan, but it's a little tricky not to spill.
 * 2) Bake at 350 °F (175 °C) for 40–45 minutes.
 * 3) Serve hot, cold, and with or without milk—the choice is yours.

Notes, tips, and variations

 * For another variation, add ½ cup (120 g) wheat flakes, ½ cup (120 g) granulated sugar plus 1 tablespoon molasses instead of brown sugar, 1 ½ cups (360 ml) soy milk instead of dairy milk, ½ cup (120 ml) vegetable oil instead of butter, and a third egg.

title: Cookbook:Baked Oatmeal