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Rhetoric and Composition/Revising

Overview of Revising
Successful writers understand that revising is an integral part of the writing process. It is important for authors to spend the majority of their time revising their texts. Revising and editing are two separate processes that are often used interchangeably by novice writers. Revising requires a significant alteration in a piece of writing, such as enriching the content, or giving the piece clarity; editing, however, is not as involved and would include fixing typos and grammatical errors. Although editing can be a part of this process, revising generally involves changes that concern bigger issues, such as content and organization. While revising, a writer might notice that one idea needs to be developed more thoroughly, and another idea omitted. The writer might decide that rearranging paragraphs will provide clarity and support for their argument, strengthening the paper as a whole. Writers should also change grammar and punctuation while revising, but if that is all they are doing then they are simply editing.

This chapter is meant to provide sound advice about the revising process.

Differences Between Revising, Editing, and Proofreading
It is important to note that revising, editing, and proofreading are very different processes. Despite the differences, however, they often overlap. They are being separated here for ease of explanation.

Revising
 * Revising is done throughout the writing process, with special emphasis on the first few drafts.
 * Focus = big issues
 * Audience
 * Organization
 * Content
 * Evidence
 * Conclusion

Editing Proofreading
 * Editing is done throughout the writing process, with special emphasis on the middle and final drafts.
 * Focus = technical issues
 * Usage
 * Word choice
 * Transitions
 * Mechanics
 * Proofreading is reserved for the final draft.
 * Focus = mechanics and presentation
 * Spelling
 * Punctuation
 * Format
 * Typographical errors
 * Textual inconsistencies

A Change for the Better
Writing is an intellectually challenging, and draining, activity -- writing well, that is. Putting ideas on paper is a good start, but revising those ideas so that they are persuasive, cogent, and form a solid argument is the real work of writing. As you review what you have written, you will undoubtedly see holes in your logic, sentences that confuse rather than clarify, and sentences and paragraphs out of place. Below are some helpful hints to consider as you analyze and transform your paper.
 * Take a break. Looking at your paper later will help you see it from the point of view of the audience. A good rule of thumb is to wait at least a day before revising. Often, writers look at their prose a day later and recognize significant flaws they would not have noticed had they written their paper in one night.
 * Be your own critic. You are obviously your own best critic. When writing, most people do not (and should not) turn in their first drafts. So take advantage of your first, second, and third drafts to write your opinions in the margins. Highlight the things you really like, and circle the things you would like to change.
 * Read and re-read your paper. In the first read-through consider the clarity of both the focus and the purpose of the paper. Does every supporting statement agree with the thesis? In the second read-through analyze organization, logical development, and correctness. Often, reading your text aloud reveals awkward phrasing, missing information, weak points, and illogical reasoning.
 * Put yourself in the shoes of your reader. Look at your work through their eyes. Keep in mind that, while you may know something about a topic and write about it with supported research, your audience may be new to the topic. Being specific in your writing helps clarify your message to audiences. Do not assume that your audience already knows what you know.
 * Cut unnecessary words. Inexperienced writers should be able to cut 20 percent (or more) of their prose. Look hard at each word, each phrase, and each sentence. Does each and every one help you achieve your purpose? Does each sentence in a paragraph relate to the main idea? If you are like most people, you will find unnecessary repetition rampant in your writing. Pruning the verbiage will result in leaner, tighter, and more forceful writing. Remember E.B. White's mantra: "Omit needless words. Omit needless words. Omit needless words."
 * Understand that revising your paper should not be the last thing you do -- revision should be ongoing throughout the creation of a document.

After doing all this by yourself, seek help from others. First, find an individual who knows about the assignment, your intended audience, and the purpose of the essay. Then, share it with someone who fits the description of the audience for whom the document is intended. Ask your readers if everything is clear and easily understood, if phrases are worded correctly, if the document is logically sound, etc. If you have other specific concerns -- Is the second example effective? Does my conclusion resolve the paper nicely? -- ask your readers to direct their attention to those issues.

After you have written your paper, return to the beginning to see how the end relates to the beginning. Have you maintained the same tone and main idea throughout? Does the ending reiterate your main idea without just summarizing what you've already said? Pay close attention to your word usage; try to leave little room for misinterpretation when the audience reads your piece.

It is also often times helpful to have someone read your paper aloud to you. This will force you to go over the material more slowly and allow you another chance to absorb the content of the paper. When you read your own paper aloud you are more apt to read the paper as it's intended it to be read, as opposed to reading what is actually on the page.

After going through the steps above and making changes as necessary, you should feel your paper is nearly complete. The content should be in place, and your text should make your case clearly and forcefully. If you feel this is the case, you are ready to closely edit and proofread your text.

Introductions
When you look over the draft of your paper, the first thing you should focus on is your introduction [|introduction]. Whether it is one paragraph or an entire chapter, the purpose of the introduction is to grab your readers' attention while simultaneously giving a preview of the information that will be included in the following paragraphs. Make sure you draw your readers in from the beginning and follow with interesting and supportive information. If readers are not intrigued from the very beginning of the piece, they will quickly become distracted avoid reading any further.

What is the difference between a good and a bad introduction? A bad introduction is misleading, rambling, incoherent, boring, or so hopelessly vague that you know less about the topic than you did before you read it. On the other hand, a good introduction gets to the point, gives the reader a reason to keep on reading, and sets the stage for a really exciting performance. An introduction is like a first impression; it is crucial to your image and, once presented, you never get a second opportunity. Your essay's introduction is your reader's first impression of your ability as a writer. Even if you are brilliant and have great ideas, a muddy or boring introduction will turn away many of your readers.

Make sure that you don't beat around the bush in your intro. If you have tedious openers such as "in today's society" or openers that merely relay what the assignment is, change it so that it instead states your argument up front and presents a clear thesis right away, then subtly describe your paper's overall structure. Try summarizing every paragraph into one sentence each, then put them all together to see if your introduction covers each point. Your introduction should state the issue at hand, establish your position regarding it, describe your paper's organization, and identify the scope of your coverage. However, be careful not to write a wordy or overly dense introduction; your introduction should merely frame the rest of the paper.

Thesis Statements
A thesis is not only an idea, but it is also a theory that provides direction and guidance on what one is talking about. It is a theory because it is an abstract type of generalized thinking that binds the whole piece of writing together and also provides a goal and a standard for the paper. theory Next, make sure you have a clear thesis. Simply put, a thesis is your main point, the line of argument that you are pursuing in your essay. It should answer two simple questions: What issue are you writing about, and what is your position on it? A thesis statement is a single sentence (or sometimes two, which are combined using a semicolon or comma and conjunction) that provides the answers to these questions clearly and concisely. Ask yourself, "What is my paper about, exactly?" to help you develop a precise and directed thesis, not only for your reader, but for you as well.

How can you be sure that your thesis is clear? Will your reader be able to identify it and see that the rest of your paper is supporting your argument? One sign of a weak thesis would be that the statement does not make a concise claim, or the claim it does make is already proven true from its factual contents.

Most American readers expect to see the point of your argument (the thesis statement) within the first few paragraphs. This does not mean that you have to place it there every time. Some writers place it at the very end, slowly building up to it throughout their work, to explain a point after the fact. Others don't bother with one at all, but feel that their thesis is "implied" anyway.

Avoid the "implied thesis" unless you are certain of your audience. Almost every professor will expect to see a clearly discernible thesis sentence in the intro. Remember: The harder it is for you to write your thesis statement, the more likely it is that your entire essay is incoherent and unfocused. If you are having real problems crafting a good thesis statement, you may need to start over, narrow your topic, or dig even more deeply into what you are trying to say and write.

A good basic structure for a thesis statement is "they say, I say." What is the prevailing view, and how does your position differ from it? However, avoid limiting the scope of your writing with an either/or thesis under the assumption that your view must be strictly contrary to their view.

Following are some typical thesis statements:
 * Although many readers believe Romeo and Juliet to be a tale about the ill fate of two star-crossed lovers, it can also be read as an allegory concerning a playwright and his audience.
 * The "War on Drugs" has not only failed to reduce the frequency of drug-related crimes in America, but actually enhanced the popular image of dope peddlers by romanticizing them as desperate rebels fighting for a cause.
 * The bulk of modern copyright law was conceived in the age of commercial printing, long before the internet made it so easy for the public to compose and distribute its own texts. Therefore, these laws should be reviewed and revised to better accommodate modern readers and writers.
 * The usual moral justification for capital punishment is that it deters crime by frightening would-be criminals. However, the statistics tell a different story.
 * If students really want to improve their writing, they must read often, practice writing, and receive quality feedback from their peers.
 * Plato's dialectical method has much to offer those of us engaged in online writing, which is far more conversational in nature than print.

You will know your thesis statement is finished when it contains the basic information for your argument without any major in-depth descriptions.

Position
Make sure that your reader knows your position on the issue. This should be properly expressed in your thesis, but check your entire introduction for "wishy washy" sentences. Unless you're only writing a summary, your introduction should make it clear how you feel about the issue at stake.

Avoid sentences or "thesis statements" such as the following: Are these examples stating an issue and taking a position, or merely stating what everyone knows already? Again, your reader should already know that the issue you're writing about is controversial, otherwise there would be little reason to write about it. Unless you've been instructed to merely write a report or summary of an issue, assume that your professor wants you to take a position and defend it with the best evidence you can muster. However, you should not forget to fairly analyze all positions and debate opposing viewpoints. Even if you only cater to other opinions in order to disprove them, you will have strengthened your argument as a result.
 * Abortion is a very controversial issue in America.
 * Capital punishment is both good and bad.
 * This paper will present the pros and cons of modern copyright law.

Scope
Besides explaining what your paper is about and your argument, an introduction may also state what you will and won't cover. For instance, let's say your paper is about an issue affecting mothers infected with HIV. Your introduction should reflect this focus, rather than present your paper as a general overview of HIV. If your scope isn't clear, then readers will constantly wonder when you'll address the larger topic--or even assume you simply forgot to do it.

Let's say you wanted to write a paper that argued that Ford makes better cars than Chevrolet. However, your introduction didn't mention Chevrolet at all, but instead had the line: "Ford makes better cars than any other car manufacturer." Your reader would quickly begin to wonder why you're not talking about Toyota or Nissan! Try to anticipate what your reader will expect to see covered, and, if necessary, state it explicitly:
 * Although my topic is capital punishment, I will focus on one aspect of that larger issue: the execution of convicts who are mentally ill.
 * Although we interviewed over two hundred doctors in our study, we will discuss only three of them in detail here.
 * In the following essay, I will be discussing only the first edition of Leaves of Grass, and my claims may or may not apply to Whitman's later editions.

Body Paragraphs
As you build support for your thesis in the "body" paragraphs, always ask yourself if you are spending your readers' time wisely. Are you writing unnecessarily complex and confusing sentences, or using 50 words when 5 would do? If a sentence is already plain and direct, there's no need to fluff it up. Flowery words and phrases obscure your ideas: when writing, being concise is key. For example, why write, "Cats have a tendency toward sleeping most of the day" when you could simply write, "Cats usually sleep most of the day"? How about changing "The 12th day of the month of April" to "April 12th?" Try to pick out such sentences and substitute simpler ones.

But wait--don't you need to inflate your text so you can meet the minimum word count? Wouldn't it be better to use "due to the fact that" for "because" and "in addition to" for "and," since these phrases use far more words? Answer: NO. Any experienced reader will instantly see through such a pitiful scheme and will likely become irritated by the resulting "flabby" prose. If you are having trouble meeting the minimum word count, a far better solution is to add more examples, details, quotations, or perspectives. Remember that every claim you make should be supported by specific reasons and evidence. Go back to the planning and drafting stage and really ask yourself if you've written everything useful about a topic.

Other students worry that their sentences don't sound smart enough. Compare these two sentences: Although the second sentence is longer and harder to grasp, that doesn't make it more intelligent. In fact, it's far more impressive to write a complex thought in simple prose than vice versa. Beware, however, that you do not lose meaning when you make a sentence simpler; cut out only the most unnecessary “fluffy” adjectives, but don’t sacrifice being descriptive.
 * Do not ask what your country can do for you; ask what you can do for your country.
 * Do not submit a query concerning what assets and benefits your country can bestow upon you and yours, but rather inquire as to what tasks or activities you yourself can perform and carry out that will be useful for the citizens of your own country.

How about your organization? From sentence-to-sentence, paragraph-to-paragraph, the ideas should flow into each other smoothly and without interruptions or delays. If someone tells you that your paper sounds "choppy" or "jumps around," you probably have a problem with organization and transitions. The addition of quotations from a text that relates to your topic can be an excellent way to refocus your writing and avoid unrelated ideas.

Keep in mind that very few writers can write a well-organized paper in one draft. Instead, their first drafts are disorganized and even chaotic. It takes patience to sort through this mess, consolidating related ideas into coherent paragraphs and helping the reader to follow their train of thought without derailing. Compare: The second example has better transitions between ideas and is easier to read. Note that the example with better transitions is also longer. Good transitions can improve your style and help you reach the minimum word count!
 * Proofreading is an important step in the writing process. Read your paper aloud to catch errors. Use spell check on your computer.
 * Proofreading is an important step in the writing process. One technique is to read your paper aloud, which will help you catch errors you might overlook when reading silently. Another strategy is to use spell check on your computer.

Conclusions
After all the work you have exerted on your paper, you want to end with a good conclusion. The conclusion and the introduction may be similar but may take several forms. Conclusions may be a simple restatement of your thesis to reestablish what the entire paper is about. They may also sum up your main points, reflect on the information presented, ask a thought-provoking question, or present a "call to action," telling your readers what you want them to do with the information you have presented. Often, this choice will be determined by the genre, audience, or purpose of your paper. Nevertheless, your conclusion should accurately reflect the paper's subject and provide the reader with closure.

Be sure not to end a paper with new ideas or a thesis you have not already supported or explained in the paper. Remember, a conclusion is meant to reiterate the paper’s main argument and then return the thesis to the larger issue the paper is addressing and should not present any new arguments or topics in the process.

title: Rhetoric and Composition/Revising


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Talk:Online OsiriX Documentation/Opening multiple series simultaneously

Are those patient names near the thumbnails? It wouldn't be all that hard to go back and replace them with printers' pi or something.--Polyparadigm 22:20, 6 October 2005 (UTC)

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


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Formal Logic/Sentential Logic/Derivations

= Derivations =

Derivations
In Validity, we introduced the notion of validity for formulae and for arguments. In sentential logic, a valid formula is a tautology. Up to now, we could show a formula $$\varphi\,\!$$ to be valid (a tautology) in the following ways.

 * Do a truth table for $$\varphi\,\!$$.

 * Obtain $$\varphi\,\!$$ as a substitution instance of a formula already known to be valid.

 * Obtain $$\varphi\,\!$$ by applying interchange of equivalents to a formula already known to be valid.

These methods fail in predicate logic, however, because truth tables are unavailable for predicates. Without an alternate method, we cannot use the second and third methods since they rely on knowing the validity of other formulas. An alternative method for showing a formula is valid—without using truth tables—is the use of derivations. This page and those that follow introduce this technique. Note, the claim that a derivation shows an argument valid assumes a sound derivation system, see soundness below.

A derivation is a series of numbered lines, each line consisting of a formula with an annotation. The annotations provide the justification for adding the line to the derivation. A derivation is a highly formalized analogue to—or perhaps a model of—a mathematical proof.

A typical derivation system will allow some of the following types of lines:

 * A line may be an axiom. The derivation system may specify a set of formulae as axioms.  These are accepted as true for any derivation.  For sentential logic the set of axioms is a fixed subset of tautologies.

 * A line may be an assumption. A derivation may have several types of assumptions.  The following cover the standard cases.

 * A premise. When attempting to show the validity of an argument, a premise of that argument may be assumed.

 * A temporary assumption for use in a subderivation. Such assumptions are intended to be active for only part of a derivation and must be discharged (made inactive) before the derivation is considered complete.  Subderivations will be introduced on a later page.

 * A line may result from applying an inference rule to previous lines. An inference is a syntactic transformation of previous lines to generate a new line.  Inferences are required to follow one of a fixed set of patterns defined by the derivation system.  These patterns are the system's inference rules.  The idea is that any inference fitting an inference rule should be a valid argument.

Soundness and validity
We noted in Formal Semantics that a formal language such as $$\mathcal{L_S}\,\!$$ can be interpreted via several alternative and even competing semantic rule-sets. Multiple derivation systems can be also defined for a given syntax-semantics pair. A triple consisting of a formal syntax, a formal semantics, and a derivation system is a logical system.

A derivation is intended to show an argument to be valid. A derivation of a zero-premise argument is intended to show its conclusion to be a valid formula—in sentential logic this means showing it to be a tautology. Given a logical system, the derivation system is called sound if it achieves these goals. That is, a derivation system is sound (has the property of soundness) if every formula (and argument) derivable in its derivation system is valid (given a syntax and a semantics).

Another desirable quality of a derivation system is completeness. Given a logical system, its derivation system is said to be complete if every valid formula is derivable. However, there are some logics for which no derivation system is or can be complete.

Soundness and completeness are substantial results. Their proofs will not be given here, but are available in many standard metalogic text books.

Turnstiles
The $$\vDash\,\!$$ symbol is sometimes called a turnstile, in particular a semantic turnstile. We previously introduced the following three uses of this symbol.

where $$\mathfrak{v}$$ is a valuation and $$\Gamma $$ is a set of premises, as introduced in Validity.

Derivations have a counterpart to the semantic turnstile, namely the syntactic turnstile. Item (1) above has no syntactic counterpart. However, (2) and (3) above have the following counterparts.

Item (4) is the case if and only if there is a correct derivation of $$\varphi\,\!$$ from no premises. Similarly, (5) is the case if and only if there is a correct derivation of $$\varphi\,\!$$ which takes the members of $$\Gamma\,\!$$ as premises.

The negations of (4) and (5) above are

We can now define soundness and completeness as follows:

 * Given a logical system, its derivation system is sound if and only if:

 * $$\mbox{If }\Gamma \vdash \varphi,\mbox{ then }\Gamma \vDash \varphi.\,\!$$

 * Given a logical system, its derivation system is complete if and only if:

 * $$\mbox{If }\Gamma \vDash \varphi,\mbox{ then }\Gamma \vdash \varphi.\,\!$$


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Circuit Theory/Sinusoidal Sources

Steady State
"Steady State" means that we are not dealing with turning on or turning off circuits in this section. We are assuming that the circuit was turned on a very long time ago and it is behaving in a pattern. We are computing what the pattern will look like. The "complex frequency" section models turning on and off a circuit with an exponential.

Sinusoidal Forcing Functions
Let us consider a general AC forcing function:

 * $$v(t) = M\sin(\omega t + \phi)$$

In this equation, the term M is called the "Magnitude", and it acts like a scaling factor that allows the peaks of the sinusoid to be higher or lower than +/- 1. The term ω is what is known as the "Radial Frequency". The term φ is an offset parameter known as the "Phase".

Sinusoidal sources can be current sources, but most often they are voltage sources.

Other Terms
There are a few other terms that are going to be used in many of the following sections, so we will introduce them here:

 * Period : The period of a sinusoidal function is the amount of time, in seconds, that the sinusoid takes to make a complete wave. The period of a sinusoid is always denoted with a capital T. This is not to be confused with a lower-case t, which is used as the independent variable for time.

 * Frequency : Frequency is the reciprocal of the period, and is the number of times, per second, that the sinusoid completes an entire cycle. Frequency is measured in Hertz (Hz). The relationship between frequency and the Period is as follows:

 * $$f = \frac{1}{T}$$

 * Where f is the variable most commonly used to express the frequency.

 * Radian Frequency : Radian frequency is the value of the frequency expressed in terms of Radians Per Second, instead of Hertz. Radian Frequency is denoted with the variable $$\omega$$. The relationship between the Frequency, and the Radian Frequency is as follows:

 * $$\omega = 2 \pi f$$

 * Phase : The phase is a quantity, expressed in radians, of the time shift of a sinusoid. A sinusoid phase-shifted $$\phi = +2 \pi$$ is moved forward by 1 whole period, and looks exactly the same. An important fact to remember is this:

 * $$\sin (\frac{\pi}{2}-t) = \cos (t)$$ or $$\sin (t) = \cos (t - \frac{\pi}{2})$$

Phase is often expressed with many different variables, including $$\phi, \psi, \theta, \gamma$$ etc... This wikibook will try to stick with the symbol $$\phi$$, to prevent confusion.

Lead and Lag
A circuit element may have both a voltage across its terminals and a current flowing through it. If one of the two (current or voltage) is a sinusoid, then the other must also be a sinusoid (remember, voltage is the derivative of the current, and the derivative of a sinusoid is always a sinusoid). However, the sinusoids of the voltage and the current may differ by quantities of magnitude and phase.

If the current has a lower phase angle than the voltage the current is said to lag the voltage. If the current has a higher phase angle then the voltage, it is said to lead the voltage. Many circuits can be classified and examined using lag and lead ideas.

Sinusoidal Response
Reactive components (capacitors and inductors) are going to take energy out of a circuit like a resistor and then pump some of it back into the circuit like a source. The result is initially a mess. But after a while (5 time constants), the circuit starts behaving in a pattern. The capacitors and inductors get in a rhythm that reflects the driving sources. If the source is sinusoidal, the currents and voltages will be sinusoidal. This is called the "particular" or "steady state" response. In general:

 * $$A_{in} \cos(\omega_{in} t + \phi_{in}) \to A_{out} \cos(\omega_{out} t + \phi_{out})$$

What happens initially, what happens if the capacitor is initially charged, what happens if sources are switched in and out of a circuit is that there is an energy imbalance. A voltage or current source might be charged by the initial energy in a capacitor. The derivative of the voltage across an Inductor might instantaneously switch polarity. Lots of things are happening. We are going to save this for later. Here we deal with the steady state or "particular" response first.

Sinusoidal Conventions
For the purposes of this book we will generally use cosine functions, as opposed to sine functions. If we absolutely need to use a sine, we can remember the following trigonometric identity:

 * $$\cos(\omega t) = \sin(\pi/2 -\omega t)$$

We can express all sine functions as cosine functions. This way, we don't have to compare apples to oranges per se. This is simply a convention that this wikibook chooses to use to keep things simple. We could easily choose to use all sin functions, but further down the road it is often more convenient to use cosine functions instead by default.

Sinusoidal Sources
There are two primary sinusoidal sources: wall outlets and oscillators. Oscillators are typically crystals that electrically vibrate and are found in devices that communicate or display video such as TV's, computers, cell phones, radios. An electrical engineer or tech's working area will typically include a "function generator" which can produce oscillations at many frequencies and in shapes that are not just sinusoidal.

RMS or Root mean square is a measure of amplitude that compares with DC magnitude in terms of power, strength of motor, brightness of light, etc. The trouble is that there are several types of AC amplitude:
 * peak
 * peak to peak
 * average
 * RMS

Wall outlets are called AC or alternating current. Wall outlets are sinusoidal voltage sources that range from 100 RMS volts, 50 Hz to 240 RMS volts 60 Hz worldwide. RMS, rather than peak (which makes more sense mathematically), is used to describe magnitude for several reasons:
 * historical reasons related to the competition between Edison (DC power) and Tesla (Sinusoidal or AC power)
 * effort to compare/relate AC (wall outlets) to DC (cars, batteries) .. 100 RMS volts is approximately 100 DC volts.
 * average sinusoidal is zero
 * meter movements (physical needles moving on measurement devices) were designed to measure both DC and RMS AC

RMS is a type of average: $$ p_{\mathrm{rms}} = \sqrt {{1 \over {T_2-T_1}} {\int_{T_1}^{T_2} {[p(t)]}^2\, dt}} $$

Electrical power delivery is a complicated subject that will not be covered in this course. Here we are trying to define terms, design devices that use the power and understand clearly what comes out of wall outlets.

title: Circuit Theory/Sinusoidal Sources


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Circuit Theory/Phasor Analysis

Phasor Analysis
The mathematical representations of individual circuit elements can be converted into phasor notation, and then the circuit can be solved using phasors.

Resistance, Impedance and Admittance
In phasor notation, resistance, capacitance, and inductance can all be lumped together into a single term called "impedance". The phasor used for impedance is $$\mathbb{Z}$$. The inverse of Impedance is called "Admittance" and is denoted with a $$\mathbb{Y}$$. $$\mathbb{V}$$ is Voltage and $$\mathbb{I}$$ is current.

 * $$\mathbb{Z} = \frac{1}{\mathbb{Y}}$$

And the Ohm's law for phasors becomes:

 * $$\mathbb{V} = \mathbb{Z} \mathbb{I} = \frac{\mathbb{I}}{\mathbb{Y}}$$

It is important to note at this point that Ohm's Law still holds true even when we switch from the time domain to the phasor domain. This is made all the more amazing by the fact that the new term, impedance, is no longer a property only of resistors, but now encompasses all load elements on a circuit (capacitors and inductors too!).

Impedance is still measured in units of Ohms, and admittance (like Conductance, its DC-counterpart) is still measured in units of Siemens.

Let's take a closer look at this equation:

 * $$\mathbb{V} = \mathbb{Z} \mathbb{I}$$

If we break this up into polar notation, we get the following result:

 * $$M_V \angle \phi_V = (M_Z \times M_I) \angle (\phi_Z + \phi_I)$$

This is important, because it shows that not only are the magnitude values of voltage and current related to each other, but also the phase angle of their respective waves are also related. Different circuit elements will have different effects on both the magnitude and the phase angle of the voltage given a certain current. We will explore those relationships below.

Resistors
Resistors do not affect the phase of the voltage or current, only the magnitude. Therefore, the impedance of a resistor with resistance R is:

 * $$\mathbb{Z} = R \angle 0$$

Through a resistor, the phase difference between current and voltage will not change. This is important to remember when analyzing circuits.

Capacitors
A capacitor with a capacitance of C has a phasor value:

 * $$\mathbb{Z} = C \angle \left(-\frac{\pi}{2}\right)$$

To write this in terms of degrees, we can say:

 * $$\mathbb{Z} = C \angle (-90^{\circ})$$

We can accept this for now as being axiomatic. If we consider the fact that phasors can be graphed on the imaginary plane, we can easily see that the angle of $$-\pi/2$$ points directly downward, along the negative imaginary axis. We then come to an important conclusion: The impedance of a capacitor is imaginary, in a sense. Since the angle follows directly along the imaginary axis, there is no real part to the phasor at all. Because there is no real part to the impedance, we can see that capacitors have no resistance (because resistance is a real value, as stated above).

Reactance
A capacitor with a capacitance of C in an AC circuit with an angular velocity $$ \omega $$ has a reactance given by

$$\mathbb{X} = \frac {1}{\omega C} \angle (-90^{\circ})$$

Reactance is the impedance specific to an AC circuit with angular velocity $$ \omega $$.

Inductors
Inductors have a phasor value:

 * $$\mathbb{Z} = L \angle \left(\frac{\pi}{2}\right)$$

Where L is the inductance of the inductor. We can also write this using degrees:

 * $$\mathbb{Z} = L \angle (90^\circ)$$

Like capacitors, we can see that the phasor for inductor shows that the value of the impedance is located directly on the imaginary axis. However, the phasor value for inductance points in exactly the opposite direction from the capacitance phasor. We notice here also that inductors have no resistance, because the resistance is a real value, and inductors have only an imaginary value.

Reactance
In an AC circuit with a source angular velocity of $$ \omega $$, and inductor with inductance L.

$$\mathbb{X} = \omega L \angle (90^\circ)$$

Impedances Connected in Series
If there are several impedances connected in series, the equivalent impedance is simply a sum of the impedance values:

[ Z1 ][ Z2 ]--- ... ---[ Zn ]---  ==> ---[ Zseries ]---

 * $$\sum_{series} \mathbb{Z}_n = \mathbb{Z}_{series}$$

Notice how much easier this is than having to differentiate between the formulas for combining capacitors, resistors, and inductors in series. Notice also that resistors, capacitors, and inductors can all be mixed without caring which type of element they are. This is valuable, because we can now combine different elements into a single impedance value, as opposed to different values of inductance, capacitance, and resistance.

Keep in mind however, that phasors need to be converted to rectangular coordinates before they can be added together. If you know the formulas, you can write a small computer program, or even a small application on a programmable calculator to make the conversion for you.

Impedances in Parallel
Impedances connected in parallel can be combined in a slightly more complicated process:

 * $$\mathbb{Z}_{parallel} = \frac{\prod_N Z_n}{\sum_N Z_n}$$

Where N is the total number of impedances connected in parallel with each other. Impedances may be multiplied in the polar representation, but they must be converted to rectangular coordinates for the summation. This calculation can be a little bit time consuming, but when you consider the alternative (having to deal with each type of element separately), we can see that this is much easier.

Steps For Solving a Circuit With Phasors
There are a few general steps for solving a circuit with phasors:

 * 1) Convert all elements to phasor notation
 * 2) Combine impedances, if possible
 * 3) Combine Sources, if possible
 * 4) Use Ohm's Law, and Kirchoff's laws to solve the circuit
 * 5) Convert back into time-domain representation

Unfortunately, phasors can only be used with sinusoidal input functions. We cannot employ phasors when examining a DC circuit, nor can we employ phasors when our input function is any non-sinusoidal periodic function. To handle these cases, we will look at more general methods in later chapters

Network Function
The network function is a phasor, $$\mathbb{H}$$ that is a ratio of the circuit's input to its output. This is important, because if we can solve a circuit down to find the network function, we can find the response to any sinusoidal input, by simply multiplying by the network function. With time-domain analysis, we would have to solve the circuit for every new input, and this would be very time consuming indeed.

Network functions are defined in the following way:

 * $$\mathbb{H} = \frac{\mathbb{Y}}{\mathbb{X}}$$

Where $$\mathbb{Y}$$ is the phasor representation of the circuit's output, and $$\mathbb{X}$$ is the representation of the circuit's input. In the time domain, to find the output, we would need to convolute the input with the impulse response. With the network function, however, it becomes a simple matter of multiplying the input phasor with the network function, to get the output phasor. Using this method, we have converted an entire circuit to become a simple function that changes magnitude and phase angle.

Gain
Gain is the amount by which the magnitude of the sinusoid is amplified or attenuated by the circuit. Gain can be computed from the Network function as such:

 * $$Gain = \left| \mathbb{H}(\omega) \right|

= \frac{\left| \mathbb{Y}(\omega) \right|}{\left| \mathbb{X}(\omega) \right|} $$

Where the bars around the phasors are the "magnitude" of the phasor, and not the "absolute value" as they are in other math texts. Again, gain may be a measure of the magnitude change in either current or voltage. Most frequently, however, it is used to describe voltage.

Phase Shift
The phase shift of a function is the amount of phase change between the input signal and the output signal. This can be calculated from the network function as such:

 * $$\angle \mathbb{H}(\omega) = \angle \mathbb{Y}(\omega) - \angle \mathbb{X}(\omega)$$

Where the $$\angle$$ denotes the phase of the phasor.

Again, the phase change may represent current or voltage.

title: Circuit Theory/Phasor Analysis


text:
Circuit Theory/Circuit Functions

Circuit Functions
This appendix page will list the various values of the variable H that have been used throughout the circuit theory textbooks. These values of H are all equivalent, but are represented in different domains. All of the H functions are a ratio of the circuit input over the circuit output.

The "Impulse Response"
The impulse response is the time-domain relationship between the circuit input and the circuit output, denoted with the following notation:

 * $$h(t)$$

The impulse response is, strictly speaking, the output that the circuit will produce when an ideal impulse function is the input. The impulse response can be used to determine the output from the input through the convolution operation:

 * $$y(t) = h(t) * x(t)$$

The "Network Function"
The network function is the phasor-domain representation of the impulse response. The network function is denoted as such:

 * $$\mathbb{H}(\omega)$$

The network function is related to the input and output of the circuit through the following relationships:

 * $$\mathbb{Y}(\omega) = \mathbb{H}(\omega) \mathbb{X}(\omega)$$

Similarly, the network function can be received by dividing the output by the input, in the phasor domain.

The "Transfer Function"
The transfer function is the laplace-transformed representation of the impulse response. It is denoted with the following notation:

 * $$H(s)$$

The transfer function can be obtained by one of two methods:

 * 1) Transform the impulse response.
 * 2) Transform the circuit, and solve.

The Transfer function is related to the input and output as follows:

 * $$Y(s) = H(s) X(s)$$

The "Frequency Response"
The Frequency Response is the fourier-domain representation of the impulse response. It is denoted as such:

 * $$H(j \omega)$$

The frequency response can be obtained in one of three ways:

 * 1) Transform the impulse response
 * 2) Transform the circuit and solve
 * 3) Substitute $$s = j \omega$$ into the transfer function

The frequency response has the following relationship to the circuit input and output:

 * $$Y(j \omega) = H(j \omega) X(j \omega)$$

The frequency response is particularly useful when discussing a sinusoidal input, or when constructing a bode diagram.

title: Circuit Theory/Circuit Functions


text:
Talk:Introduction to Psychology/Introduction

> the first page will eventually turn into the second. The idea of where psychology is derived from will give psychology a lot more meaning. As with other sciences, such as sociology that is derived from history and philosophy, psychology is from philosophy and biology.

The many great contributors and thinkers that brought in their wisdom to help advance this field to the smallest degree is important because they were all building blocks. --Cyberman 03:26, 7 October 2005 (UTC)

> Someone kindly edit/remove the first two sentences of the third paragraph. They are just copied from the first two sentences of the first paragraph. Please look into it. --yourparthi@gmail.com 14:40, 8 February 2012 (UTC)


text:
IB Chemistry/Energetics

6.1 Exothermic and Endothermic Reactions
6.1.1 : If the reaction produces heat (increases the temperature of the surroundings) then it's exothermic. If it decreases the temp (that is, absorbs heat) then it's endothermic. Also, the yield of an equilibrium reaction which is exothermic will be increased if it occurs at low temps, and so for endothermic reactions at high temps.

6.1.2 : Exothermic -> a reaction which produces heat. Endothermic -> a reaction which absorbs heat. Enthalpy of reaction -> the change in internal energy (H) through a reaction is ∆H.

6.1.3 : ∆H will be negative for exothermic reactions (because internal heat is being lost) and positive for endothermic reactions (because internal energy is being gained).

6.1.4 : The most stable state is where all energy has been released...therefore when going to a more stable state, energy will be released, and when going to a less stable state, energy will be gained. On an enthalpy level diagrams, higher positions will be less stable (with more internal energy) therefore, if the product is lower, heat is released (more stable, ∆H is -ve) but if it is higher, heat is gained (less stable, ∆H is +ve).

6.1.5 : Formation of bonds -> release of energy. Breaking of bonds -> gain / absorption of energy.

6.2 Calculation of enthalpy changes
6.2.1 : change in energy = mass x specific heat capacity x change in temperature --> E = mc∆T

6.2.2 : Enthalpy changes (∆H) are related to the number of moles in the reaction...if all the coefficients are doubled, then the value of ∆H will be doubled (attention must be paid to limiting reagents though).

6.2.3 : When a reaction is carried out in water, the water will gain or lose heat from (or to) the reaction, with hopefully little escaping the water. Therefore, the change in energy, and so the ∆H value, can be calculated with E = mc∆T where E is equal to ∆H, m is the mass of water present, and c = 4.18 kJ Kg-1 K-1. This ∆H value can then be calculated back to find the enthalpy change for each mol of reactants.

6.2.4 : The solution should be placed in a container as insulated as possible, to keep as much heat as possible from escaping. The temperature should be measured continuously, and the value used in the equation is the maximum change in temp from the initial position.

6.2.5 : The results will be a change in temperature. this can be converted into a change in heat (or energy) by using the above equation and a known mass of water. this can be used to calculate the ∆H for the amount of reactants present, and then this can be used to calculate for a given number of mols.

6.3 Hess' Law
6.3.1 : Hess' Law states that the total enthalpy change between given reactants and products is that same regardless of any intermediate steps (or the reaction pathway). To calculate:

1) Reverse any reactions which are going the wrong way and invert the sign of their ∆H values (multiply by -1)

2) Divide or multiply the reactions until the intermediate products will cancel out when the reactions are vertically added (always multiply/divide the ∆H value by the same number)

3) Vertically add the reactions.

4) Divide or multiply the resulting reaction to the correct coefficients.

6.4 Bond enthalpies
6.4.1 : Bond enthalpy (aka dissociation enthalpy) -- the enthalpy change when one mole of bonds are broken homolitically in the gas phase. ie X-Y(g) -> X(g) + Y(g) : ∆H(dissociation). Molecules such as CH4 have multiple C-H bonds to be broken, and so the bond enthalpy for C-H is actually an average value. These values can be used to calculate unknown enthalpy changes in reactions where only a few bonds are being formed/broken.

6.4.2 : If the reaction can be expressed in terms of the breaking and formation of bonds in a gaseous state, then by adding (or subtracting when bonds are formed) the ∆H values the total enthalpy of reaction can be found.

6.5 Entropy
6.5.1 An increased disorder (entropy) can be caused by mixing two different types of particles, increased movement of particles (including state changes), or increased number of particles. Increasing the number of particles in a gaseous state gives the largest change in entropy.

6.5.2 Since ∆S = -∆H/T, if ∆H is -, then ∆s is positive, and visa versa.

6.6 Free Energy
6.6.1 Standard free energy of reaction is the free energy that a reaction takes or gives at standard values of temperature and pressure. ∆G = ∆H - T.∆S

6.6.2 If ∆G is negative, the reaction is spontaneous. If ∆G is positive, the reaction is not spontaneous.

6.6.3 If ∆sT > ∆H, the reaction is spontaneous. If temperature drops so that ∆sT < ∆H, then the reaction is non-spontaneous.

=HL Material=

15.1

15.1.1 Standard state is what the element naturally tends to be at. The standard enthalpy of formation is the change in enthalpy that accompanies the formation of one mole of a compound from its elements with all substances in their standard states.

15.1.2 ∆Hof = ∑∆Hof products - ∑∆Hof reactants

15.2

15.2.1 Lattice Enthalpy is the enthalpy of a lattice structure, such as a diamond. If the sign of the enthalpy is negative, the lattice is formed. If +, it does not.

15.3

15.3.1 ∆S = ∆Sproducts - ∆Sreactants

15.3.2 Use the equation ∆G = ∆H –T∆S or ∆G = ∆Gproducts - ∆Greactants

title: IB Chemistry/Energetics


text:
IB Chemistry/Kinetics

Kinetics is a study of the progress of a chemical reaction, especially the rate of the reaction.

Rates of Reaction
The rate of reaction is concerned with how quickly a reaction reaches a certain point. Technically, it is defined as the increase of product concentration over time, or, the decrease of reactant concentration over time. The SI unit of rate of reaction is mol/dm3, which means moles per dm3 or moles per liter. In short, the rate of a chemical reaction can be generalized as the following, when X is a reactant: $$\frac{\Delta[X]}{\Delta time}$$

The rate of reaction can only be determined experimentally.

7.1.2 : Interpretation of rate graphs. Reaction rate graphs will generally be graphed with time on the x-axis and some measure of how far the reaction has gone (ie concentration, volume, mass loss etc) on the y-axis. This will generally produce a curve with, for example, the concentration of the reactants approaching zero.

A range of factors can be considered to express the rate of reaction. These can include: mass, volume, conductivity, colour, concentration etc.

The Collision Theory
Collision Theory is an extension of kinetic-molecular theory that explains the physical conditions that cause chemical reactions to occur. It states that in order for a chemical reaction to occur between two particles, three conditions must be fulfilled:

 * 1) Reactants must collide
 * 2) Reactants must collide in the correct orientation.
 * 3) Reactants must have sufficient kinetic energy (above the required activation energy).

The energy required for reactants to form its products is called the activation energy (denoted as Ea). The activation energy is essential in kinetics, as it allows us to determine whether if a reaction can take place. A reaction is said to be spontaneous when it able to produce reactants.

The Collision Theory
Collision Theory is an extension of kinetic-molecular theory that explains the physical conditions that cause chemical reactions to occur. It states that in order for a chemical reaction to occur between two particles, three conditions must be fulfilled:

 * 1) Reactants must collide in the correct ratio.
 * 2) Reactants must collide in the correct orientation.
 * 3) Reactants must collide with energy greater and or equal to the activation energy.

The energy required for reactants to form its products is called the activation energy (denoted as Ea). The activation energy is essential in kinetics, as it allows us to determine whether if a reaction can take place. A reaction is said to be spontaneous when it able to produce reactants.

What Happens During a Reaction
A chemical reaction is essentially involves two processes, bond breaking and bond forming. As mentioned in the Energetics chapter, particles tend to react to become more stable.

The Reaction Coordinate
The reaction coordinate, also called the reaction pathway, describes the changes in energy in the system throughout the reaction. The reaction coordinate is usually presented graphically, in a diagram called the energy profile (see Fig. 1). The activation energy is the energy change from the reactants to the highest energy state of the reaction.

Enthalpy Change
ΔH, or enthalpy change, is the difference between the energy of the system when reactants are formed and the energy of the system when products are formed. Enthalpy is very similar to energy, but enthalpy is the energy of the system under a constant pressure. The enthalpy change is particularly important, as it determines whether if the reaction is exothermic, or endothermic. As you might have noticed on the graph, the energy of the A+B are higher than that of C+D. Where did the energy go? The energy is released outside the system, in other words, the energy is released to the environment. Reactions that result in energy released to the environment are called exothermic reactions. When the energy of reactants are lower than that of products, then energy is absorbed into the system, making the reaction endothermic.

Usually, the energy released to the environment in the form of heat energy, enabling us to detect a rise in temperature. However, the released energy can also be released in the form of light and sound energy. Similarly, endothermic reactions, which absorbs energy from the environment, cause an increase in energy in the system, usually resulting in a drop in temperature. This description leads to one of the most common misconceptions of endothermic reactions, as you may wonder why temperature decreases when energy is increased in the system. Energy is stored in bonds of the particles in the system in the form of chemical energy, rather than heat energy. Therefore, when a decrease in temperature is detected (using an instrument or through touch), heat energy is decreased in the environment.

7.2.1 : Collision theory -- reactions take place as a result of particles (atoms or molecules) colliding and then undergoing a reaction. Not all collisions cause reaction, however, even in a system where the reaction is spontaneous. The particles must have sufficient kinetic energy, and the correct orientation with respect to each other for the two to react. Even then, the transition state may revert to the reactant molecules instead of forming the product molecules.

7.2.2 : Higher temperature causes a greater average kinetic energy of the particles in a material. This leads to a faster reaction because there are more collisions, and each collision is more likely to succeed.

Higher concentrations cause more collisions and therefore a faster reaction.

Catalysts may provide an alternative pathway with lower activation energy and increase the probability of proper orientation. Each collision is more likely to succeed and this results in a faster reaction.

In heterogeneous reactions (where the reactants are in different states) the size of the particles of a solid may change reaction rate, since the surface is where the reaction takes place, and the surface area is increased when the particles are more finely divided; therefore smaller solid particles in a heterogeneous reaction cause a faster reaction.

7.2.3 : Most reactions involve several steps, which can be individually slow or fast, and which, all together, make up the complete reaction. The slowest of these steps is called the rate determining step, as is determines how fast the reaction will go. It is also not necessary that all the reactants are involved in every step, and so the rate determining step may not involve all the reactants. as a result, increasing their concentration (for example) of a reactant which is not involved in the rate determining step will not change the overall reaction rate.

The Reaction Coordinate
The reaction coordinate, also called the reaction pathway, describes the changes in energy in the system throughout the reaction. The reaction coordinate is usually presented graphically, in a diagram called the energy profile (see Fig. 1). The activation energy is the energy change from the reactants to the highest energy state of the reaction.

Enthalpy Change
ΔH, or enthalpy change, is the difference between the energy of the system when reactants are formed and the energy of the system when products are formed. Enthalpy is very similar to energy, but enthalpy is the energy of the system under a constant pressure. The enthalpy change is particularly important, as it determines whether if the reaction is exothermic, or endothermic. As you might have noticed on the graph, the energy of the A+B are lower than that of C+D. Where did the energy go? The energy is released outside the system, in other words, the energy is released to the environment. Reactions that result in energy released to the environment are called exothermic reactions. When the energy of reactants are lower than that of products, then energy is absorbed into the system, making the reaction endothermic.

Usually, the energy released to the environment in the form of heat energy, enabling us to detect a rise in temperature. However, the released energy can also be released in the form of light and sound energy. Similarly, endothermic reactions, which absorbs energy from the environment, cause an increase in energy in the system, usually resulting in a drop in temperature. This description leads to one of the most common misconceptions of endothermic reactions, as you may wonder why temperature decreases when energy is increased in the system. Energy is stored in bonds of the particles in the system in the form of chemical energy, rather than heat energy. Therefore, when a decrease in temperature is detected (using an instrument or through touch), heat energy is decreased in the environment.

7.2.1 : Collision theory -- reactions take place as a result of particles (atoms or molecules) colliding and then undergoing a reaction. Not all collisions cause reaction, however, even in a system where the reaction is spontaneous. The particles must have sufficient kinetic energy, and the correct orientation with respect to each other for the two to react. Even then, the transition state may revert to the reactant molecules instead of forming the product molecules.

7.2.2 : Higher temperature causes a greater average kinetic energy of the particles in a material. This leads to a faster reaction because there are more collisions, and each collision is more likely to succeed.

Higher concentrations cause more collisions and therefore a faster reaction.

Catalysts may provide an alternative pathway with lower activation energy and increase the probability of proper orientation. Each collision is more likely to succeed and this results in a faster reaction.

In heterogeneous reactions (where the reactants are in different states) the size of the particles of a solid may change reaction rate, since the surface is where the reaction takes place, and the surface area is increased when the particles are more finely divided; therefore smaller solid particles in a heterogeneous reaction cause a faster reaction.

7.2.3 : Most reactions involve several steps, which can be individually slow or fast, and which, all together, make up the complete reaction. The slowest of these steps is called the rate determining step, as is determines how fast the reaction will go. It is also not necessary that all the reactants are involved in every step, and so the rate determining step may not involve all the reactants. as a result, increasing their concentration (for example) of a reactant which is not involved in the rate determining step will not change the overall reaction rate.

=HL Material=

Topic 16 is the additional HL material for Topic 7.

Activation energy

title: IB Chemistry/Kinetics


text:
IB Chemistry/Equilibrium

Equilibrium

Equilibrium primarily deals with reversible reactions and the state of equilibrium itself. Equilibrium can be defined as a state reached of a reversible reaction, in which the rate of the forward and backward reactions equal.

Dynamic equilibrium
8.1.1 : In all reactions, there are in fact two reactions occurring, one where the reactants produce the products, and the other where the products react to form the reactants. In some reactions, this second reaction is insignificant, but in others there comes a point where the two reactions exactly cancel each other out...thus the reactants and products remain in equal proportions, though both are continually being used up and produced at the same time.

8.2 The position of equilibrium

8.2.1 : The equilibrium constant Kc is a constant which represents how far the reaction will proceed at a given temperature.

8.2.2 : When Kc is greater than 1, products exceed reactants (at equilibrium). When much greater than 1, the reaction goes almost to completion. When Kc is less than 1, reactants exceed products. When much less than 1 (Kc can never be negative...so when it is close to zero) the reaction hardly occurs at all.

8.2.3 : The only thing which can change the value of Kc for a given reaction is a change in temperature. The position of equilibrium, however, can change without a change in the value of Kc.

Effect of Temperature : The effect of a change of temperature on a reaction will depend on whether the reaction is exothermic or endothermic. When the temperature increases, Le Chatelier's principle says the reaction will proceed in such a way as to counteract this change, ie lower the temperature. Therefore, endothermic reactions will move forward, and exothermic reactions will move backwards (thus becoming endothermic). The reverse is true for a lowering of temperature.

Effect of Concentration : When the concentration of a product is increased, the reaction proceeds in reverse to decrease the concentration of the products. When the concentration of a reactant is increased, the reaction proceeds forward to decrease the concentration of reactants.

Effect of Pressure : In reactions where gases are produced (or there are more mols of gas on the right), an increase in pressure will force the reaction to move to the left (in reverse). If pressure is decreased, the reaction will proceed forward to increase pressure. If there are more mols of gas on the left of the equation, this is all reversed.

8.2.4 : Based on the previous section, you should be able to predict what's going to happen given a reaction if the temperature, pressure, or concentration is changed.

8.2.5 : A catalyst does not affect either Kc or the position of equilibrium, only the rate of reaction.

8.2.6 : N2(g) + 3H2(g) <=> 2NH3(g) : delta-H = -92.4 kJ mol-1 as can be seen, there are more mols of gas on the left than the right, so a greater yield will be produced at high pressure. The reaction is exothermic, therefore it will give a greater yield at low temperatures, however this is not possible as the rate of reaction becomes too low, and the temperature must actually be increased. A catalyst of finely divided iron is also used to help speed the reaction (finely divided to maximize the surface area).

=HL Material=

Topic 17 is the additional HL material for Topic 8.

title: IB Chemistry/Equilibrium


text:
IB Chemistry/Acids and Bases

This is chapter 9, and this space will hopefully house an introduction to the chapter.

Properties of acids and bases in aqueous solution
A reaction between a strong acid and a strong base produces water and a salt. For a reaction between a weak acid with a strong base, or between a strong acid with a weak base, only a salt is produced. For example:

$${}^{\rm{HCl} + \rm{NaOH} \to \rm{H}_2\rm{O} + \rm{NaCl}}$$

$${}^{\rm{HCl} + \rm{NH}_3 \to \rm{NH}_4\rm{Cl}}$$

Acids reacting with metals will produce hydrogen gas, e.g. $${}^{2 \rm{HCl} + \rm{Mg} \to \rm{MgCl}_2 + \rm{H}_2}$$.

Acids reacting with carbonates will produce water and carbon dioxide, e.g. $${}^{2 \rm{HCl} + \rm{CaCO}_3 \to \rm{CO}_2 + \rm{H}_2\rm{O} + \rm{CaCl}_2}$$.

Experimental properties of acids and bases
When acids and bases neutralize, the reaction is noticeably exothermic (i.e.,		heat can be felt coming from the reaction). Obviously, they will have an effect on the color of indicators as described below. The hydrogen produced in the reaction of acids with metal will produce a 'pop' sound if a match is held to it, and the CO2 from the carbonate reaction will turn limewater a milky white when bubbled through it. Examples of some acids: $${}^{\rm{HCl}}$$, $${}^{\rm{CH}_3\rm{COOH}}$$, $${}^{\rm{H}_2\rm{SO}_4}$$, $${}^{{\rm{NH}_4}^+}$$.

Examples of bases: $${}^{\rm{NaOH}}$$, NH3, CH3COO-.

8.1.1: Define acids and bases according to Brønsted Lowry theory
According to the Brønsted-Lowry theory, acids are defined as proton (H+ ion) donors and bases are defined as proton acceptors.

For a compound to act as a B-L acid, it must have a hydrogen atom in it, which it is capable of losing while remaining fairly stable. A BL base must be capable of accepting a hydrogen ion while remaining relatively stable (or reacting to form a stable		compound, e.g. water and a salt). Some compounds (such as water) may act as both, e.g. (H2O-> OH- or H3O+). These substances are called "amphoteric".

Acid base reactions always involve an acid-base conjugate pair. If the reactant is an acid, the matching product is its conjugate base, e.g. HCl/Cl-, CH3COOH/CH3COO-, NH4+/NH3.

The conjugate base will always have one less H atom than the acid (or the acid one more than the base). In compounds where there are many hydrogen atoms, the one which is held the weakest is generally the one which is lost, and this must be reflected in the writing of the compound, as in the CH3COOH example above.

Lewis theory
Lewis defined acids as electron pair acceptors and bases as electron pair donors.

A simple proton-hydroxide reaction shows that this is equivalent to Brønsted-Lowry theory:

H+ + :OH- --> H-OH

The proton is accepted because the hydroxide has a pair of electrons with which it forms a covalent bond to the proton.

Lewis theory goes beyond Brønsted-Lowry theory to describe non-proton acid-base reactions:

F3B + :NH3 --> F3B-NH3

Ligands and nucleophiles can be classed as Lewis bases. Lewis acids include metal ions and electrophiles.

Ag+ + 2 :NH3 --> [Ag(NH3)2]+

8.3.1 Distinguish between strong and weak acids and bases in terms of the extent of dissociation, reaction with water and electrical conductivity.
Strong and weak acids are defined by their ease of losing (or donating) a proton. A strong acid, when placed in water, will almost fully ionise/dissociate straight away, producing H3O+ ions from water. a weak acid will, however, only partially do this, leaving some unreacted acid remaining. This is set up as		an equilibrium, and so when some of the H3O+ ions produced by a weak acid are reacted, LCP means that more of the acid will react to form H3O+ ions. This means that, given an equal number of moles of acid, they will be neutralized by the same amount of strong base, but their solutions will have different pH values. A weak base is the same as this, only it accepts protons and so produces OH- ions from water rather than H3O+. Any solution's ability to conduct electricity is defined by its ionic charges. As a result, a strong acid will produce more charged ions than a weak one, and so its solution will be a better electrical conductor than a weak acid. The same goes for strong/weak bases.

Examples of strong and weak acids and bases
Strong acids : HCl, HNO3, H2SO4, HClO3, HBr .

Weak acids : CH3COOH, H2CO3.

Strong bases : group 1 hydroxides (e.g. NaOH, etc.), BaOH.

Weak bases : NH3, CH3CH2NH2.

8.3.3 - Distinguish between strong and weak acids and bases and determine the relative strengths of acids and bases using experimental data.
The strength of an acid or base can obviously be measured with a universal indicator or a pH meter, and also the rate of reaction. Hydrogen production with metals or CO2 with CaCO3 will reveal the strength of an acid. The relative acidities can also be found by neutralizing two acids with a strong base in the presence of an indicator.

pH values range up and down from 7 (being the neutral value		of pure water at 25°C and 1 atmosphere). Lower pH value are acidic; higher values are basic. pH can be measured with a pH meter, or with pH paper (paper containing a mixture of indicators to cause a		continuous color change). pH is a measure of the concentration of H3O+ ions.

If we have two solutions with their pH values, the lower one will be more acidic and the higher one will be more basic (though they could both still be basic/acidic with respect to		water – pH 7).
9.4.3 : a change of 1 in the pH scale represents a 10 times change in the acidity or basicity of the solution (because it is a logarithmic		scale). Concentration is equal to 10-pH or pH=-log10[H3O+] where [H3O+] is the concentration of hydrogen ions in solution.

HL Material
Topic 18 is the additional HL material for Topic 9.

Brønsted-Lowry acids and bases

An acid is a substance that can donate a proton, or hydrogen ion A base is a substance that can accept a proton, or hydrogen ion

Lewis theory

A Lewis acid is a lone pair acceptor and a Lewis base is a lone pair donor.

Calculations involving acids and bases
This HL Sub-topic is Sub-topic 5 of SL Option A, with one difference: The SL Option does not require knowledge of Ka x Kb = Kw.

Indicators
Indicators change colour depending in the presence of acid or base. Here is a table of common indicators:

Table adapted from: Stark JG & Wallace, HG (1982) Chemistry Data Book p103 2nd ed, John Murray, London.

title: IB Chemistry/Acids and Bases


text:
Introduction to Psychology/Human Development

Biological Basis of Behavior
Like every other aspect of life, behavior is determined largely by an individual's DNA makeup. DNA can be considered as a "blueprint" for every aspect of life. Evolutionary psychologists study the role of natural selection in the passing on of behavioral and other psychological traits. Genetic makeup is generally believed to account for much of an individual's temperament.

Structure and Function of DNA
The nucleic acids are the largest of the organic molecules. DNA stands for deoxyribonucleic acid. It is made up of units called nucleotides, which themselves are composed of a deoxyribose 5-carbon sugar molecule, a nitrogen base, and a phosphate group. These nucleotides are bonded in columns by phosphate covalent bonds (very strong), and are laterally bound to other nucleotides with weaker hydrogen bonds. Nucleotides are arranged such that they form genes, which are specific biochemical units that code for a characteristic. In DNA replication, DNA is split and transcribed to form proteins, which are the basic structural units of life. Individual-to-individual variance, introduced in reproduction and meiosis, is the basis for different personality traits and differences in temperament between individuals.

Natural Selection in Behavioral Traits
The theory of natural selection may be applied to psychological, as well as biological traits. This is known as evolutionary psychology or the evolutionary perspective.

The basic idea of evolutionary psychology is this; genetic mutations are capable of altering not only an organism's physical traits, but also its behavioral traits. Like physical traits, these mutations may help the organism reproduce and pass its mutation on to the next generation. This theory explains how behaviors like mating rituals and migration came to be multi-generation rituals in some species.

Controversy Surrounding
Presently, the evolutionary psychology perspective is extremely controversial as it is unable to be scientifically proven in a laboratory setting and is, by definition, very susceptible to hind-sight bias.

In Early Human Development
Consider the following- in a population's gene pool, the normal genotype is for an infant that is unattached to its mother- it will crawl away and does not have any "love" or other significant attachment to its mother. Over time, mutations accumulate and there develops another genotype that causes infants to become uncomfortable and cry when their mothers leave. Naturally, the crying infant that signals distress will have more protection from the elements and other predatory environmental forces. Thus, the "attached" infant will have a higher chance of survival. Over many generations, more "attached" infants will survive to mate and pass on the allele for secure attachment. Thus, a new behavior has developed by means of natural selection.

This illustrates the basic idea behind evolutionary psychology in human development; that the innate behaviors of very young children are pre-programmed in their genotypes and that we can understand these behaviors by studying the environmental forces that surrounded our ancestors.

Piaget's Theory of Cognitive Development
See link for more information on Piaget. http://www.learningandteaching.info/learning/piaget.htm

The Nature-Nurture Controversy
One of the central debates in psychology involves the origin of human behavior. Is it, as theorized by many, caused by biological factors present in the human body, or is it caused by interactions between the individual and its environment (including other individuals of its species) that finally lead to changes in both behavior and even physical structure? This debate has often been termed Nature versus Nurture, and is not an easy one to solve.

Nature Human behavior is the result of already-present biological factors

Strict adherents of the nature philosophy often use genetic code as support for their theory. It contains the instructions for millions of protein commands that eventually determine our basic structure as human beings. But is it definitive? And can it be changed?

Nurture Human behavior is the result of interaction with ones environment

As for Nature adherents, there is also strong evidence that supports followers of the Nurture philosophy. It is well documented that interaction with ones environment can provoke changes in brain structure and chemistry, and that situations of extreme stress can cause problems like depression.

 * http://en.wikipedia.org/wiki/Jean_Piaget
 * * http://en.wikipedia.org/wiki/Piaget%27s_theory

http://en.wikipedia.org/wiki/Developmental_psychology

 * http://en.wikipedia.org/wiki/Kohlberg%27s_stages_of_moral_development
 * * http://en.wikipedia.org/wiki/Lawrence_Kohlberg

 * http://en.wikipedia.org/wiki/Erik_Erikson
 * * http://en.wikipedia.org/wiki/Erikson%27s_stages_of_psychosocial_development
 * * http://en.wikipedia.org/wiki/Attachment_theory

Back to Table of Contents << Previous chapter||Next chapter >>


text:
Cookbook talk:American pizza

I don't think pizza should be in with "pie". I've heard of a "pizza pie" of course, but it's not a proper pie. It's not made out of pastry (more of a bread) and it's not filled with anything (only topped)... "Pizza" is more of a classification in and of itself (or maybe with other topped flatbreads). Kellen T 04:38, 7 October 2005 (UTC)

 * Yes, it's definitely not a pie. I'd really like to keep the page organized into sections. We can have a crust section, with links to various crust recipes, and so on. The choice of sauce is unrelated to the choice of cheese, the choice of topping is unrelated to the choice of crust, etc. AlbertCahalan 05:03, 7 October 2005 (UTC)

 * A pie isn't supposed to be filled with anything. A pie is something that is baked and holds the rest of the dish together.  Pizzas are pies.  It's like a pumpkin pie or a pasty, they're all pies.  I don't see a reason for putting section divisons in a short piece like this, it's an index of sorts to the various pizza recipes to be filled in.  Hell, the Original Pizza recipe there isn't even a proper pizza, it's one of the americanized ones.  Nmontague 06:40, 7 October 2005 (UTC)

 * Nope, a pie is definitely filled. I won't agree that a pie must be pastry, because it could have a crumb crust, but a yeast bread or soda bread would be wrong. AlbertCahalan 07:31, 7 October 2005 (UTC)

 * The section divisions serve to divide the sections. Without section divisions, the crust info runs right into the next section and so on. AlbertCahalan 07:31, 7 October 2005 (UTC)

 * Since pizza is an American food, "americanized" is redundant. Pizza is no less American than Chop Suey and Crab Rangoons. I won't object to listing an Italian proto-pizza on the page though. AlbertCahalan 07:31, 7 October 2005 (UTC)

 * That is very wrong-headed of you, claiming pizza for the United States is like claiming apple pie, apple pie is an English thing. Just because someone lays a claim to something does not make it valid.  Much like the hotdog isn't American, but is just a frankfurter from Germany renamed.  And a pizza is definately a pie, claiming otherwise is either ignorance or invalid knowledge on the subject.  Nmontague 08:53, 7 October 2005 (UTC)

 * The Merriam-Webster Dictionary has, as the only two food-related definitions:
 * a meat dish baked with biscuit or pastry crust -- compare POTPIE
 * a dessert consisting of a filling (as of fruit or custard) in a pastry shell or topped with pastry or both
 * That would include the cobbler, crisp, bearclaw, and danish. It would not include a pizza.
 * AlbertCahalan 01:58, 8 October 2005 (UTC)

 * I won't claim the apple pie. I don't want to claim the hot dog, but sadly I must. I'm quite sure that the vile concoction of beef and synthetic casing is nothing like a traditional German sausage. AlbertCahalan 01:58, 8 October 2005 (UTC)

Pizza an American Dish? No Way!
While pizza, in all it's myriad forms, has become a staple of Italian-American cooking, it is most definitely rooted in classic Italian cooking. Reliable ovens were a rarity in Italy until the second half of the 20th century, especially in small villages. Breads, etc. were prepared at home then taken to the village bakery for cooking. Pizza developed as a way to both utilize left-over dough and create an easy supper dish on baking days. William Peterson 08:26, 13 May 2006 (UTC)
 * does anyone really believe that pizza is American? No comment... JackkBrown 22:48, 30 June 2024 (UTC)

Change the photo
That photo is just revolting. Surely there's a better, more representative photo of pizza!

 * Changed.

title: Cookbook talk:American pizza


text:
Talk:Io Programming

Things to document
I think we need to add pages and samples for the following topics so that this book can really become a good starting point for comprehensive Io learning:
 * Common file operations (opening, reading lines of text, writing, reading bytes and lengths and seeking through binary files)
 * Socket operations (along the lines of file operations, but discuss Io's buffering and making connections or using servers and handlers in more detail)
 * Discuss the 'type' slot created on protos whose slot names are capitalized
 * Discuss the 'proto' and 'protos' slot and how and when to use appendProto or prependProto.

Error?
Enter the Io's interactive interpreter (by typing  at the console) and type the following:

write("Hello, world!\n")

With the interactive interpreter, this should look like:

user@computer:~$ io Io> write("Hello, world!\n") Hello, world! ==> "Hello, world!\n"

There is no message sent back in my Io version!? My output looks like this: Io> write("Hello, world!\n") Hello, world! ==> Nil

Use print, assign the string to a variable, put the code in a file then use io or try return it.

 * Not an error. Nil is the return value of the write method. The wikibook may be wrong, or the display is implementation dependant. -- Edwin

But there is an issue if you try to run Io in some implementations of Emacs and other 'shell' programs that offer readline, editline or some type of libedit for cmd history and edits. Io fails to output to Stdout in those cases, prehaps because it does not consider the re-directed STDOUT to be a handle. I have raised this issue in my blog at plymouthreliable.com

title: Talk:Io Programming


text: User talk:67.189.4.32

title: User talk:67.189.4.32


text: User talk:61.95.199.21

title: User talk:61.95.199.21


text: User talk:203.199.114.33

title: User talk:203.199.114.33


text: User talk:81.25.2.172

title: User talk:81.25.2.172


text:
User talk:212.69.231.226

Please stop. If you continue to vandalize pages, you will be blocked from editing Wikibooks.

title: User talk:212.69.231.226


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

Overview
Levicorpus levitates a victim in the air by their feet.

Extended Description
This spell is one of the spells that Harry Potter learned from the Half-Blood Prince's Advanced Potion-Making textbook.

Harry first sees his father, James Potter, use this spell on Severus Snape in one of Snape's memories. Harry later attempts this spell on Ron not knowing what it would do.


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Wikibooks:Templates/Media

Printable versions
pl:Wikibooks:Szablony/Media

title: Wikibooks:Templates/Media


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User:Alexevasion~enwikibooks

My extended bio can be found at

Some of my thoughts about the direction of the wikiversity project follow... My name is Alex Goldman. I am a PhD student in the Department of Sociology at the University of Florida. You can find out more about me at www.clas.ufl.edu/users/agoldman. The idea of open source social science has recently captivated my attention. presented a poster at the American Sociological Society this August on the concept and I hope to find as many other people as possible to help develop this project further. I am also in the process of writing a social theory paper based on the idea that the information technologies that have made the Wikimedia projects possible now provide the impetus for a real transition away from our educational and journalism institutions (and the industries that support them) having a monopoly on the power to produce and distribute "knowledge". I don't want to come off as here as sounding pompous (no worries – it’s really poorly written) or overly judgmental, since this is my first contribution to the wiki project, but I am very skeptical of the way that this idea of wikiversity is currently being characterized (and I guess advanced albeit slowly). The idea of accreditation to me seems folly as does the overriding focus of reproducing the textbook paradigm (which as anyone in education can tell you one of the ugliest rackets around). What encouraged me to really get involved in this project was a post I found by a "WoWo" [] whom I have not yet been able to contact. I have no expertise in anything but the social sciences, so I will do my best to keep my remarks centered on matters I see as directly related to this supposed body of knowledge. The wikibooks project (which is certainly an improvement over Project Gutenberg) is a noble idea that is motivated by a true hope for more widespread public access to information. I understand that access problems abound. However, I would posit that the larger dimension of the access problem has to do with the way that most "credible knowledge" looks today. Most of the books that get produced in today’s universities are so highly specialized that 99% is directed at only a small community of like-minded specialists would be interested enough to even try to comprehend it. Most of the really cool cutting edge stuff is published in academic journals anyway. For a layperson to be able to begin to fully comprehend this kind of material, they would need access to the preceding work which made the "production" of this new "knowledge" possible. The current system behind academic journals makes access very expensive. Still, none of this really matters because the information presented within is so densely jargon laden and pedantic (at least in the social sciences) that no one would want to read it anyway. To me, the purpose of the wikiversity project (as the wikipedia project) is to provide a structure that rewards people for slogging through this information and helping to digest and excrete a well summarized version of what the document had to say. This is possible to do. In fact, this is what graduate students in the social sciences spend most of their time doing. The problem is that the various summaries do not follow a set format and are not archived in a centralized location. This should be the most basic role for this social science wiki. The next step is to begin to integrate this knowledge into a format more centered on debates over current events. The founding purpose of the social sciences was to help the public find ways to improve the quality of their lives. Many would say that this mandate has never really been fulfilled, but instead distorted and repackaged into mostly impotent academic institutions. This project must revitalize these concerns by organizing itself around the issues that concern the public most. For instance, there is greatly uninformed discussion taking place all over the country (but in my home state of Florida in particular) about the issue of child molestation. To even begin to understand the nature of this phenomenon, you need to understand what studies in psychology, sociology, anthropology, economics, law, history, and other research areas have to contribute to the discussion. I could spend the next five hundred words engaged in delineating just the broadest disciplinary areas that address the different but interlocking angles on this issue, but I will instead leave it as a worthy thought exercise for the general readership. At current, no information source exists where that people can get a good synthesis of the knowledge that relates to this issue. The mainstream media will produce a butchered abridged version made with entertainment in mind (though NPR did the best they could in an hour) and academics will produce disparate studies that touch on various angles of the problem that they could procure institutional funding to carry out, but they will likely never be put in a context where they can speak to one another to produce a higher level account of the situation and what needs to be done. Open Source Social Science holds the promise of enlisting the general public to take on this job - which is one that neither academics nor journalists were suited for in the first place. Disciplinary boundaries are not entirely useless (but likely outmoded by ever increasing specialization), but it is a waste of energy to focus on reproducing them here. Our job is to facilitate the production of small summaries of recent social science documents which will in turn provide the materials cited in a central synthesis which should be marketed toward the literate public. The challenge is to provide a structure for these "issue pages" that will be able to honor and integrate the many different explanations that the different disciplines (and factions within the disciplines) will provide. Other than the nasty habit of confronting powerful groups, the key factor which has held the social sciences back since their inception is their ununified accounts (this is always in comparison to the natural sciences) about what is happening in the world. Infighting is largely unproductive and should be minimized through wiki talk pages and left mostly to academics. However, I believe that this diversity of thought is indeed an advantage if it can be presented in the correct format. This project can do this only because of the "liquid information" advantage that the internet - and open source wikis in particular - now provide. To get this idea off the ground, I recommend the following strategies: Find professors who are interested in teaching (they can’t be too research oriented or they would never take on the added burden) and convince them to alter the nature of their class assignments to provide the necessary summarizing student labor force needed to produce primary raw source material on which this project will run. I believe this can be done in a way that actually improves how much students learn in a course (see my syllabus). Alternatively, if they are not willing to go that route for one reason or another, there is the other option of producing summaries and extensions of the information that makes up various textbooks in a particular course (there are many competing publishers). This is not up to date material, but its saving grace is that it supposedly represents an index of the best studies ever produced in a particular field, which of course would be a significant boon to the project (its backbone really). Now, to get the general public involved in the process, I think two main strategies are appropriate. One would be to have them searching just outside of the academic gates of journal subscriptions and college library cards. This means that they will scour other materials that are available to them: journalism sources, blogs, websites, public records, census data, etc. The phenomena of a news dump is perhaps the most analogous concept. Basically, you put out a call for help on finding info on a particular topic and interested people go to work. The only issue is how to keep them from doing redundant work, but I think that issue is of a more technical and organizational nature – programmers and leaders please stand up. Another would be to have them actually develop their own research agendas. This could be as simple as just talking to some neighbors or much more complicated using research methodology that hopefully we could provide them with scaffolding to help them acquire necessary skills through this very project. At first blush, independent public research would likely produce myriad ethics controversies, but here is not the place to deliberate on this matter. Finally, a permanent search committee should be established to find individuals with the skills and knowledge background necessary to produce the synthesis issue pages that will serve as the front door to the world. They must be able to comprehend and cull an incredible amount of information to produce worthy overarching position pieces. However, it would seem that as soon as these pages go up, they will recruit more and more people who have more attuned and thus more efficient information gathering skills. A system to rate the quality of particular contributors from their past submissions could likely be established to improve efficiency further. This is still but a skeletal idea structure, but I hope it advances the general debate I have seen. If nothing else, it represents me throwing my hat in the ring. I’m serious about making these ideas a reality and I hope to find like minded others to collaborate with on this project as soon as possible.

title: User:Alexevasion~enwikibooks


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User talk:Alexevasion~enwikibooks

I left a comment at Talk:Wikiversity:School_of_Social_Science. Cheers. Cormaggio 13:55, 7 October 2005 (UTC)

traveling kids
i studied anthropology at fsu, minor in sociology. Had an honors thesis on the similarities between traveling kids and huntergatherers. You should email me at cbc06@fsu.edu

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 Alexevasion. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Alexevasion~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 22:56, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 04:30, 19 April 2015 (UTC)

title: User talk:Alexevasion~enwikibooks


text: User talk:80.6.236.32

title: User talk:80.6.236.32


text: User talk:213.115.24.238

title: User talk:213.115.24.238


text:
Budget Watch Collecting

This book is a resource for collecting vintage watches on a budget.

There are plenty of resources for collecting expensive watches--There are some brands with more articles on them than watches produced. On the other hand, information on everyday middle-class watches can be hard to find.

This book will (eventually) cover most aspects of collecting inexpensive vintage (mostly mechanical) watches, as well as inexpensive methods to get them running again.

Like any Wiki, you can edit and contribute, click here for details.

Contents

 * /Watch Identification/
 * /Watch Company and brand history/
 * /Budget Watch Repair, restoration and maintenance/
 * /Other Budget Watch resources/
 * /How to buy and sell watches/
 * /Watch Photography/
 * /Horological Theory/
 * /Spotting Fakes/

title: Budget Watch Collecting


text:
MediaWiki talk:Uploadtext

Please change commons logo to Image:Commons-logo.svg
 * Any reason? --Derbeth 17:07, 7 October 2005 (UTC)
 * Yes, it is redundant and will be deleted on commons. SVG is better than PNG anyways. --84.131.93.168 17:14, 7 October 2005 (UTC)
 * Thanx. --84.131.93.168 17:33, 7 October 2005 (UTC)

Uploading images to commons - german template
I have German in my user preferences, and the upload template in German language is bad. I would like to translate the English upload form to German, but where shall I put it?

Regards --SoylentGreen (talk) 12:14, 22 March 2009 (UTC)

title: MediaWiki talk:Uploadtext


text: User talk:82.131.131.108

title: User talk:82.131.131.108


text:
Guide to Unix/Explanations/Connecting to Remote Unix

If the shell prompt is on a remote server, ssh is the most common way to access it. The server must be running the sshd server software to accept your connection. The SSH protocol encrypts your connecting to prevent spying and stealing of passwords. All that is required is that you trust the computer that you connect from and the server where your account is located.

To connect, open your SSH client, specify the name of the server and your username. Most servers use the default port 22, so specifying the port is not necessary. (Be careful with ports 1024 and higher because these are controlled by users, not the system administrator.)

Using SSH from a Shell Prompt
To connect to one Unix-like system from another, you can the ssh shell command. This command is often OpenSSH, a popular SSH implementation from OpenBSD. For example, Tux wants to connect to an account (username tux) on the computer "linux.example.edu": $ ssh tux@linux.example.edu tux@linux.example.edu's password:

If Tux has the same username on the local computer, then specifying the username is optional: $ whoami tux $ ssh linux.example.edu tux@linux.example.edu's password:

Accepting the Key Fingerprint
The first time you connected, you saw a message similar to the following: The authenticity of host 'linux.example.edu (1.2.3.4)' can't be established. RSA key fingerprint is a4:3d:fe:10:7e:45:2b:29:d0:fe:ed:ba:a3:21:66:a1. Are you sure you want to continue connecting (yes/no)?

If you are reasonably sure that you connected to the correct computer (an attacker on the Internet might steal your connection to learn passwords) then you can answer 'yes' and add linux.example.edu to the list of known hosts. Some SSH clients also allow you to say 'yes' to one session only.

When you say 'yes', you get a message such as: Warning: Permanently added 'linux.example.edu,1.2.3.4' (RSA) to the list of known hosts.

This means that your SSH client "knows" linux.example.edu. It will verify that future connections to "linux.example.edu" reach the same computer (or cluster). You will be alerted if an attacker steals your connection, but also if linux.example.edu changes its key. Thus, if you know that linux.example.edu changed its key and you recognize the key, then you can ignore the alert.

graphical connections
Most tasks on a Unix machine can be done in text mode, from the shell prompt.

However, once the text-mode ssh connection is working, many people feel more comfortable switching to a graphical interface.

A typical setup has a VNC viewer on the local end and a X11/VNC server on the remote end, and a ssh tunnel. (Any VNC viewer -- including ssvnc, sshvnc, or a Java-enabled web browser -- will work with any VNC server). The ssh software grabs all information that would normally flow through the VNC ports (ports 5900 through 5906 and ports 5800 through 5806) and funnels them through the ssh tunnel (by default, port 22).


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Cookbook:Tigernut

Tigernuts are not nuts, but edible tubers with a slightly sweet, nutty flavour compared to the more bitter tasting tuber of the "purple nutsedge". They are quite hard and are generally soaked in water before they can be eaten. They have various uses, in particular they are used in Spain to make horchata. They are sometimes known by their Spanish name, chufa. Other common names for these tubers are "earthalmond" and "yellow nutsedge".

The tubers were originally cultivated by the ancient Egyptians. Commercial production in Europe is almost exclusively in the Valencia region of Spain. West African countries such as Ghana and Nigeria are major producers for the domestic market.

Tiger nuts have excellent nutritional qualities with a fat composition similar to olive oil and a rich mineral content, especially phosphorus and potassium. Tiger nuts are also gluten and cholesterol free, and have a very low sodium content.

According to the Consejo Regulador de Chufa de Valencia (Regulating Council for Valencia's Tigernuts), the nutritional composition/100 ml of a classical Horchata de Chufas, or Orxata de Xufes in Valencian language, is as follows: energy content around 66 kcal, proteins around 0.5 g, carbohydrates over 10 g with starch at least 1.9 g, fats at least 2 g.

title: Cookbook:Tigernut


text:
Cookbook talk:Tigernut

This module is originally based on text from The English Wikipedia article of the same name. The edit history at the time of access is as follows:

 * 1)  04:01, 2 October 2005 84.80.126.99
 * 23:58, 26 September 2005 67.170.85.248 (corrected spelling of "temperate")
 * 19:59, 21 August 2005 66.90.205.229 (Fixed some grammer)
 * 02:24, 7 August 2005 Andydocrm
 * 17:46, 6 August 2005 69.229.115.136
 * 15:08, 6 August 2005 Andydocrm m
 * 15:04, 6 August 2005 213.140.21.231 (expanding nutritional and historical information about "chufa")
 * 09:37, 22 July 2005 ZwoBot m (robot Modifying: es)
 * 11:52, 13 June 2005 DanielCD (fix taxobox pic)
 * 11:13, 11 June 2005 Iustinus
 * 00:57, 11 June 2005 Iustinus (Added image. Can someone fix the formatting?)
 * 11:16, 4 June 2005 Gdrbot m (Robot-assisted disambiguation: L.)
 * 00:50, 24 May 2005 212.250.136.45
 * 12:16, 20 May 2005 DanielCD (Category:Poales)
 * 13:42, 7 May 2005 Michel BUZE m
 * 03:08, 4 May 2005 Jonnabuz (Added taxobox, wikified, sorted stub)
 * 11:54, 3 May 2005 Delpino m

title: Cookbook talk:Tigernut


text:
User talk:Kaeding

Copyright problem with Image:MovingResonator.JPG
--Derbeth 18:28, 7 October 2005 (UTC)

title: User talk:Kaeding


text:
Budget Watch Collecting/Watch Identification

Budget Watch Collecting/Timex date codes

Budget Watch Collecting/Timex model names

Budget Watch Collecting/Timex movements

Budget Watch Collecting/Timex related brands

Budget Watch Collecting/Unknown Swiss Made

Budget Watch Collecting/Identifying movements

Budget Watch Collecting/Bulova Caravelle date codes

Budget Watch Collecting/Identifying by style

Budget Watch Collecting/Seiko serial numbers

Budget Watch Collecting/Types of Movements

Waltham serial number lookup

Elgin serial number lookup

Movement Database Mostly jeweled mechanical

Seiko Movement Table

Identifying a vintage watch can be frustrating. Only a few have any easy means of identifying when a particular watch was made. Timex mechanicals and electromechanicals after 1962 have a model number on the dial, the last two numbers correspond to the year made. Bulova brands after 1948 have a 2 character code-The first digit is the decade, the second is the year. Waltham and Elgin have serial number databases on-line covering early watches. For some watches the only clues are the movement and the overall style--Even the brand name may not explain anything.