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Problems In High School Chemistry/PhChem/thermo1/table

Fill in the missing values in the table. The table contains 63 blanks, so we expect a student to solve the table in 90 minutes.

Note: -

1.) Each of the processes are carried out on 1 mole of ideal gas.

2.) The odd numbered processes are for monoatomic ideal gases, while the rest are for diatomic ideal gases. For a monoatomic ideal gas, Cv = (3/2)R and for a diatomic ideal gas, Cv = (5/2)R. Cp = Cv + R, so theyre (5/2)R and (7/2)R respectively; not considering the vibrational degrees of freedom which we neglect at relatively low temperatures.

3.) Throughout the entire page, ∫PextdV implies the definite integral over the initial and the final stages as the lower and upper limits respectively. It DOES NOT designate the indefinite integral.

The Question
If you feel stumped by the sheer lack of data in the table, know that this is not an impossible task. It is, actually, a mechanical, mindless work. This is mainly because the table doesn't require a proper understanding of a process and the related intricacies. All it demands is a harmony among the formulae in the student's mind. Filling up this table will give a strong practice of the mathematics involved, and will also benefit the student in simplifying the more complex numerical problems.

If you still do not gather any courage to fill the table, you should consider solving the introductory problems.

The Answer
      Process    T i    V i
 P i
 T f
 V f
 P f
 Q
 ∆E
 W
 ∫P ext dV
 ∆H

 1
 Rev. Adiabatic
 400K
 02.0 L
 16.42 atm
 252K
 04.0 L
 05.18 atm
 0
 -  1846 J
 -1846J
 1846J
 -3076J

 2
 Rev. Adiabatic
 300K
 24.63 L
 01.00 atm
 365K
 29.96 L
 02.00 atm
 0
 1351J
 -1351J
 1351J
 1891J

 3
 Isobaric Rev.
 300K
 24.63 L
 01.00 atm
 600K
 49.26 L
 01.00 atm
 6236 J
 3741J
 -2495J
 2495J
 6236J

 4
 Rev. Isothermal
 300K
 03.0 L
 8.21 atm
 300K
 06.0 L
 04.10 atm
 1729 J
 0
 -1729J
 1729J
 0

 5
 Rev. Isothermal
 250K
 03.0 L
 6.84 atm
 250K
 10.26 L
 02.00 atm
 2556 J
 0
 -2556J
 2556J
 0

 6
 Rev. Isochoric
 352    K
 14.44 L
 02.00 atm
 400K
 14.44 L
 02.27 atm
 1000 J
 1000J
 0
 0
 1397J

 7
 Irrev. Adiabatic
 270    K
 38.63 L
 0.57 atm
 350K
 28.73 L
 01.00 atm = ext pressure
 0
 1000J
 1000J
 -   1000J
 1663J

 8
 Irrev. Isothermal
 424    K
 01.0 L
 34.81
 424K
 3.48 L
 10.00 atm = ext pressure
 500    J
 0
 -500J
 0500 J
 0

Column 1
(a)Pi - Since three of the gas parameters are known, the fourth parameter can always be found using the ideal gas equation on the initial state.

(b)Tf - Ideal gas equation has four parameters, only two are known, so we need one more equation.

Since this is a reversible adiabatic process, the pressure P and Volume V satisfy the relation (P)(V^y) = constant throughout. Also, the ideal gas equation is satisfied throughout in any reversible process. PV = nrt. Devide the first equation by the second, and you'll find that you just eliminated one unknown - P. It is now left to one equation, Ti[Vi^(y-1)] = Tf[Vf^(y-1]) and one unknown, Tf.

The final calculations require a simple use of log tables. In competitive exams however, the paper setter will give all the values of the logarithms involved, so you need not concern yourself with the complexity of the calculations.

(c)Pf - Now that three quantities in the ideal gas equation are known, you can easily find Pf.

Alternatively, you could directly find Pf through using P(V^y) = constant on initial and final stages of the process, and then used the ideal gas equation to find Tf. Notice that we avoided finding Pf when we were asked to find only Tf, by eliminating the unknown.

(d)Q - In an adiabatic process, the heat exchanged with the surroundings is ________

(e)∆E - Internal energy is fairly simple for an ideal gas, and depends only upon temperature of the ideal gas. It is nCvTf at Tf, and nCvTi at Ti. So the change, then, is nCv(Tf-Ti). Try to relate it to the expression for heat gained and heat lost learnt in thermal physics in the eleventh and ninth standard in Indian Schools.

(f)w - It is the additive inverse of ∫PextdV in Chemistry conventions. In Physics, it is the same as ∫PextdV. See below on how to find ∫PextdV, that is the work done by the gas during the change in volume.

(g)∫PextdV - Well, performing the whole integration by substituting P is a good idea. P = nrt/v will not work because even T will vary. We cannot integrate two variables in this way. Instead, substitute P as [Constant]/(V^y) and carry out the integration. After the integration is done, substitute the value of constant as Pf(Vf^y) and Pi(Vi^y) to get the result in terms of known quantities.

But, the same work can be done in an easy manner! Use the first law, Q = ∆E + ∫PextdV. You will find that in an adiabatic process, since the heat exchanged is 0, ∫PextdV becomes the additive inverse of the change in the internal energy. In laymen's terms, since in an adiabatic process, the heat input is zero, whatever work that is done by the gas comes at the expence of its internal energy (and vice versa). This explaining subtly why the First Law Of Thermodynamics is actually the manifestation of the law of conservation of energy.

**NOTE :: The integral requires the value of Pext. In a reversible process, since the External Pressure is the same as the internal pressure of a gas, the whole substitution makes sence. Remember, Pext is not necessrily equal to nrt/v, but internal pressure = nrt/v.**

(h)∆H - Finally, the enthalpy change of the reaction. It is pleasing to know that this again, depends only on the change in temperature for an ideal gas. That is, ∆H = nCp∆T. The First Column, Done!!!

Column 2
(a)Vi - Use the ideal gas equation over the first state.

(b)Tf - Ideal gas equation, this time again, will have two unknowns. We need one more equation, which comes from (P)(V^y) = constant. Going exactly by the steps in column one, however, we won't be eliminating the unknown Vf, while eliminating the known P. Instead, to eliminate Vf, while keeping the knowns, raise both sides of the ideal gas equation by Y and devide the first equation by the second. You will end up with (T^y)[P^(1-Y)] = constant. Use it on the initial and final stages.

(c)Vf - Now that three quantities in the ideal gas equation are known, you can easily find Vf.

Alternatively, you could directly find Vf through using P(V^y) = constant on initial and final stages of the process, and then used the ideal gas equation to find Tf. Notice that we avoided finding Vf when we were asked to find only Tf, by eliminating the unknown.

(d)Q - What is the defining charachteristic of an adiabatic process?

(e)∆E - nCv∆T pretty simple. :)

(f)w - Tip::Throughout the table, this column is going to be the additive inverse of ∫PextdV

(g)∫PextdV - Tip::Although not throughout the table, but in any kind of adiabatic process (reversible or irreversible), ∫PextdV is the abditive inverse of ∆E, according to the first law.

**This is because the first law of the thermodynamics is universal, and it doesnt matter if the process is reversible or irreversible to apply it.

However, the ideal gas equation and any results derived from it are applicable only in the case of a thermodynamic equilibrium. Since this is not possible in case of an irreversible process, we cannot use the mentioned equations over the course of the reactions. Even then, the ideal gas equation can be used before and after an irreversible process takes place.**

(h)∆H - ∆H = nCp∆T. Second column completed as well.

The Third Column
(a)Vi - the _______ equation, fill in the blank mentally. (b)Vf - Again, two unknowns for the ideal gas equation. But is Pf actually an unknown? Remember that this is an isobaric process, and that the initial pressure is known, so the final pressure is known as well. (c)Pf - Done (d)Q - Non zero for the first time!! We will use the first law, Q = ∆E + ∫PextdV. See it again as the law of conservation of energy, the heat supplied is used in heating the gas as well as doing work. Now find the other two terms. (e)∆E - nCv∆T :) (f)∫PextdV - Since this is a reversible process, the external pressure is the same as the internal pressure, and the internal pressure is constant. It comes out of the integration. So we are left with  (P)∫dV, which evaluates to P∆V. Do the needful!!  (h)∆H - nCp∆T !!!  Note : - In evaluating ∫PextdV, make sure that you use the correct units of each quantity! Since we want the answer to be in joules, i.e. SI units, we need to substitute pressure and volume in Pascals and Cubic Meters.  Note : - The enthalpy change of a reaction is the heat exchanged in a reaction when a process is carried out at constant pressure. This, in our case, means that the Q and ∆H entries in column three should be same. [Have you convinced yourself why?] But there may be slight differences between the two entries, this resulting from the rounding off of conversion factors. e.g. 1 atm = 101325 Pascals, but we often substitute 1 atm as 1.01 lac pascals. Third column done as well. :)

Column Four
(a)Pi - ;)  (b)Tf - This question is the answer, "what is an isothermal process?"  (c)Pf- The ideal gas equation is OK, but observe that the RHS of it is constant. So, even the LHS would be. Hence, if the volume doubles up, the pressure reduces to half.  (d)Q - ∆E + ∫PextdV, now we will find both the terms and substitute them.  (e)∆E - Well, if the internal energy of an ideal gas depends only on its temperature, and if this is an isothermal process, where does it lead us?  (f)∫PextdV - This is a reversible process. As explained above, Pext is the same as the pressure of the gas molecules at any stage. Substitute Pext as nrt/v. Since the numerator is constant, we take it out of integration, and evaluate nrT ∫(dV/V) which is nrTln(Vf/Vi). Now substitute the values.  (g)∆H - nCp∆T :)

Column Five
No additional info. This is a clone actually.

Column Six
We expect the student to be seasoned enough now to realize that the gas parameters are found through ideal gas equation, and then the thermodynamic Joule values are found simply. Note : Since the volume remains constant, change in volume is 0. i.e. dV=0, so ∫PextdV = 0

Column Seven
This is the first irreversible process that we are dealing with, in this table. Pf = 1 atm = external pressure in the above table means that the gas expands/contracts against a constant external pressure of 1 atm, and the final pressure of the gas too is 1 atm. [We have some numerical problems where the final pressure isnt equal to the external pressure against which expansion/contraction took place, but do not bother yourself with it at this moment.] Note carefully that all three gas parameters are missing for the initial state. That means, apart from the gas equation, we will require two more equations to find them all. And since this is an irreversible adiabatic process, we cannot use P(V^y)=Constant over the initial and final states. That means we have lost an equation! How are we going to deal with this situation? The first thing to keep in mind is that every problem asked in this book has a solution. And this table, like most of the highschool problems, is all about making equations to find unknowns. (a)Vf - Use the ideal gas equation to get the value. Now try to relate the final parameters to the initial parameters. Obviously, the heat gained, work done, change in internal energy put some constraints on the possible values of the parameters. (b)Ti - ∆E is known to us, but if we write it as nCv∆T, and equate it to 1000 J, we actually end up with an equation. This gives us the value of ∆T, which can be use to find the initial temperature, because the final temperature is known. (c)Vi/∫PextdV - Refer the two reversible adiabatic processes in column 1 and column 2 that we studied. We made a statement over there, that since the characteristic of any kind of adiabatic process is "zero energy exchange", ∫PextdV is always the additive inverse of ∆E for an adiabatic process. Hence ∫PextdV = -1000 J. But this is not all!! If you are thorough with integration, look at the word ∫PextdV with some concentration. The parameter Pext would jump in and out of the integral in your mind's eye once you understand that it is constant for this process. This yields ∫PextdV =Pext(∆V). Just as you found Ti by finding ∆T, find Vi by finding ∆V. Fill up the rest of the entries yourself. Note: This is for you to ponder. In the reversible adiabatic processes, ∫PextdV = -∆E and actually evaluating the integral gave the same equation. But in the case of an irreversible adiabatic process, evaluating the integral and using the first law to find its value gives two distinct equations! This can be used for our benefit in problems. Please keep this in mind!

Column Eight
Just as in Column Seven, we lose the equation ∫PextdV = nrtln(Vf/Vi), but we can write it as ∫PextdV = Pext(∆V). An irreversible isothermal process is much shorter than an irreversible adiabatic process to complete. (a)Vf - ∫PextdV = Pext(∆V) use this equation to find the final volume of the gas molecules. (b)Tf - Two gas parameters are known now, use the ideal gas equation to find Tf. And if this is an isothermal process, what does knowing the final temperature mean? The rest of the entries require no new logic, everything has been covered in the above columns.


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User talk:67.142.130.17

Please keep your queries in one place. WB:AN; we'll reply to you there.  – Mike.lifeguard  | talk 12:05, 6 September 2007 (UTC)

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

title: User talk:67.142.130.17


text:
User talk:67.142.130.14

Please keep your queries to one place. WB:AN is fine; we'll reply to you there.  – Mike.lifeguard  | talk 12:06, 6 September 2007 (UTC)

title: User talk:67.142.130.14


text:
User talk:Dnyaneshmalvankar

Thanks for your question. In the future, please ask in a more appropriate location: WB:SHD, and remember to sign your posts with four tildes: ~. So far as I know, the F-keys have specific Functions depending on the program. You might find more information here.  – Mike.lifeguard  | talk 12:16, 6 September 2007 (UTC)

title: User talk:Dnyaneshmalvankar


text:
Cookbook talk:Mapo Tofu

Vegetarian version
Just added a link (via references) to a vegetarian version of Mapo Doufu. That changes is reflected in the last 3 edits (took me a couple tries to test it & get it right) —The preceding unsigned comment was added by 202.86.139.194 (talk • contribs) 2007-09-06T22:30:22.

 * Thanks, I've moved that reference to Notes, tips, variations because it isn't part of the standard recipe. Webaware talk 03:55, 7 September 2007 (UTC)

Order of ingredients
I reordered the ingredients so that they are in order of use. This is a fairly normal way to write ingredients in recipes. Quillaja (talk) 23:34, 26 April 2009 (UTC)

Servings
About how many servings does this recipe make? That info should be included in the recipe. For me, it makes 2 servings, but I'm kinda a big eater, and so serving sizes are almost always too small for me. =P Quillaja (talk) 23:38, 26 April 2009 (UTC)

Amount of sauce or liquid in this recipe
I've made this recipe twice now, and followed the instructions exactly, but I've found that when I'm finished, the mapo tofu generally seems not to have much of a 'sauce' or 'liquid' portion, as is shown in the picture. Just my observation. The original author might want to change this. It's still tasty in the original form. Quillaja (talk) 23:41, 26 April 2009 (UTC)

title: Cookbook talk:Mapo Tofu


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A Researcher's Guide to Local History Terminology/Further reading

Books

 * Dymond, David. Researching and Writing History: a practical guide for local historians (British Association for Local History, 1999)
 * Fowler, Simon. Starting out in local history (Countryside Books, 2001)
 * Friar, Stephen. The Local History Companion (Thrupp: Sutton, 2001)
 * Hey, David. Oxford Companion to Local and Family History (Oxford: Oxford University Press, 1992)
 * Sinclair, Cecil. Tracing Scottish Local History. Scottish Record Office.(HMSO, Edinburgh 1996)
 * Tiller, Kate. English Local History: an introduction (Thrupp: Alan Sutton 1992)
 * Trubshaw, Bob. How to write and publish local history (Heart of Albion Press, 1999)
 * Winterbotham, Diana and Crosby, Alan. The Local Studies Library: a handbook for local historians (British Association for Local History, 1998)

Magazines

 * Economic History Review
 * Agricultural History Review
 * Urban History
 * Past and Present
 * Midland History
 * Northern History
 * Southern History
 * Journal of Regional and Local Studies
 * Local Population Studies
 * Local Historian

Wikimedia

 * Wikipedia Main page
 * Wikipedia article on Petrosomatoglyphs

External

 * Scottish Archive Network
 * Old Ordnance Survey Maps
 * Google Scholar
 * Agricultural History Review
 * Economic History Review
 * Victoria County History
 * The RCAHMS Canmore site
 * The Maps section of the National Library of Scotland
 * Official website of the Society of Antiquaries of Scotland
 * British Association for Local History
 * The 1901 census for England and Wales
 * Local History on Line - including many links
 * Dictionary of the Scots Language
 * Facebook group for researching the Life & Times of Robert Burns


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User talk:67.142.130.37

Please remember to sign your posts with four tildes ( ~ ) even if you're not signed in.  – Mike.lifeguard  | talk 14:12, 6 September 2007 (UTC)

title: User talk:67.142.130.37


text:
A Researcher's Guide to Local History Terminology/Researching local history

Researching local history
Local history research is often taken up as a hobby by people without prior training or experience in the appropriate techniques and approaches. The very nature of local history is such that starting points are always available locally and lay researchers can learn the necessary skills as they study their subject in ever increasing depth. Archivists and societies can provide advice, encouragement, and information; formal courses of study are also widely available.

Most local history researchers follow a process in which they start from the basic facts offered by the available evidence, make a more detailed analysis of that evidence to explore its implications, and then put that analysis in its wider temporal and geographical context. Some take a more theoretical approach: starting from a hypothesis, which they seek to demonstrate or disprove through evidence.

Using paintings, drawings, prints and photographs
Photographs are usually reliable and can be interpreted directly and with confidence. (While this is true, remember that sources are created with intent by the author. Therefore a photo essay of a community may emphasize some areas, and omit others.  As such, the use of photographic images as a primary basis for exploring a community may be limited.  This is why it is always desirable to use multiple sources.)

Paintings and prints are open to artistic interpretation and / or a formulaic construction. For example the artist Gilpin set a fashion for a romantic style of drawing and painting which influenced artists for many years and Billings is famous for his stylised and romantised representation of Scottish castles, etc. Such sources can only be 'trusted' as factual in generalised terms.

Using old maps
Privately produced antique maps often go back several centuries, the Ordnance Survey (OS) itself did not start until the 19th-century. Many maps can be found either online or are available for study at libraries, purchasable at bookshops, etc.

Comparing maps sequentially by age can reveal a great deal of information about place names (etymology), landscape features, natural habitats, changing farming practices, etc. Older OS maps may have many place names which are left out on modern OS maps.

The 'Name Book' was the written record of the OS and this can be very helpful and informative. The OS is sometimes wrong, with examples of misnamed hills, burns, historical features, etc. which have never been corrected and have been repeated by other 'official' bodies. Such errors can sometimes be identified and corrected by making comparisons with pre-OS maps, an example being where the OS at first used the name 'Drumastle Mill,' then 'Drumcastle Mill,' however a 1747 map gives 'Drumaskus Mill.' An old 'Tower' was nearby and this may have led to the OS error during re-surveying, etc.

Old maps, through comparing various surveys, can also reveal the extent to which geographical features have been altered by the activities of man. Rivers were surprisingly often diverted by natural circumstances, the landowning class, factory owners, etc.; lakes were created through mining, quarrying, road construction, etc.; small hills were removed through quarrying, etc.; lakes drained for agriculture, etc., etc.

Baronial or manorial records
The Barony became the principal administrative unit of medieval landed estates in Scotland and its business was carried out in the Barony court before the laird or his baillie. The records of the Barony, and in particular its court, document many aspects of local agriculture, the resolution of disagreements between tenants, the transfer of property amongst tenants, etc.

Many lairds also had a legal heritable jurisdiction which permitted the laird of the barony to deal with certain minor criminal matters and regulate the sale of bread and ale. Baronies continued to function in a minor way until the early 20th century, but by this date the business of the courts had for a long time been dominated by the transfer of tenants' property.

The proceedings of the court and other documents give much information about local agriculture and the management of estates. Records reveal a great deal about the community living in the barony, its social structure, households, responsibilities, and the local economy.

Etymology
The names of habitations, hills, rivers, villages, etc. can reveal a great deal about the history of such features, especially if the name can be traced throughout its existence to show subtle changes which help to positively identify the original meaning. Such changes can be very complex and confusing, especially if they involve other languages, such as Cornish, Welsh, Scottish Gaelic, etc.

Local dialects can lead the local historian astray, as with 'Watermillock' beside Ullswater in the Lake District. The name seems to imply something along the lines of 'The small mill by a stream', whilst it actually involves the dialect word 'wethers' for sheep and 'hillock', or small hill.

Even well established placenames may change with new ownership, such as with the farm 'Sandilands', which was change to 'Bankend' once Lord Torphichen of the Sandilands family, sold the estate on which the farm stood. In such cases extra confusion can effect historical researchers as the farm was renamed after a previous farm which once stood on another site some distance away.

A tradition, particularly in Victorian times, was to enhance the 'image' of a place by renaming it using more upper or middle class names. Maybole in Ayrshire for example had many streets renamed through the influence of a local minister.

A particular tradition that exists in parts of Ayrshire in Scotland and probably elsewhere, is to rename places after old family homes or estates, places of particular personal interest, etc. For example the Fergushill Manse became 'Janburrow' after Janet from Burrowland Farm and Bonnyton became 'Girgenti' after an historic site in Sicily. Landowners often altered names, such as that of Culzean castle, which used to be 'The cove', named after the caves that the castle stood on. Little Dreghorn near Dreghorn in North Ayrshire was changed to Fairlie after the family's main home on the Ayrshire coast.

Clues can also be found by speaking to local people who may provide the pronunciation of a name from a map, etc. which might be significantly different from the deduced pronunciation.

Another difficulty with the interpretation of placenames, standard expressions, etc. is that the meanings of words may have changed, for example the expression 'Pit and gallows' refers to a pit which was actually a form of dungeon or prison cell, not a pit for drowning the condemned. Words may also take on new meanings which supplant the original, for example a 'turnpike' was used for the spiral stairs in a tower and became more familiarly a term for the Toll Roads first constructed in the 18th-century.

Some descriptive terms were used very much in one locality, such as that of 'bastel-house' being confined to the East and Middle March of the Scottish - English border.

Some names can link certain features to industrial activity in the past, such as the name 'Red Boiler' which referred to the manufacture of soap at one particular site. Here the clues were that a plentiful supply of hardwood trees was a pre-requisite, together with a supply of animal carcasses, both of which the site had once provided in abundance. The folk memory of cast iron cauldrons at the site and the characteristic colour added to the circumstantial evidence.

Changes in the spoken language of an area results in the loss of some placenames and the corruption of others. Such changes may reflect such transition as that from Pictish to Gaelic to Scots and finally to English.

Personal names
The spelling of personal names, like that of placenames, was highly variable and only became consistent in the 19th century in many cases. Some spelling usages may reflect cadets of a family, such as with the Cunnnighame family, who used Cunninghame for the Glencairn and Corsehill branch; Cuninghame for Caddel and Monkredding; Cunningham for Baidland and Clonbeith; and finally Cuningham for Glengarnock.

When following family trees it is worth noting that many heirs changed their names to retain a traditional surname, as with the branch of the Seton family who inherited the Earldom of Eglinton and took the Montgomerie name associated with that title. This practise was sometimes a condition of inheritance or an act of gratitude.

Aerial and satellite imagery
Imagery from aerial reconnaissance is especially common from the first and second world wars. Some of which can be viewd in 3D. Such photographs are held by the Imperial War Museum and turn up at antique fairs, through on line auction, sites, etc. Various websites can now provide satellite imagery which gives an overview, often in considerable detail, of areas which are being researched. Many sites additionally have live links on the satellite image which provide further details and sometimes link to sites such as Wikipedia, often providing much more information to the researcher. Features are usually easy to follow, such as Corpse roads, old railways, castles, rivers, rig and furrow systems, etc.

Taken together with maps, satellite imagery can clarify or add substantially to existing knowledge on a particular topic. The imagery is however not 'live' and can be several years old. Crop marks are sometimes visible, indicating the course of old roads, the position of old dwellings, etc. Due to the imagery being from above, some vertical structures can be hard to make out, only being visible by the shadows they cast, etc.

The interpretation of landscape features
There is no alternative than to keep an open mind and to develop or seek expert advice when making deductions from features in the landscape. Oliver Rackham is well known for his pioneering work on woodlands, leading to a better understanding of previous landscapes, which sustained lost crafts such as sawyers, digging temporary sawpits which collapsed upon themselves to leave 'grave' like features. They are often found in old woods, close to water and occasionally made with stone sides. Q-pits are another landscape feature, found in woodlands or what has been woodland, they were kilns used to produce a sort of dried wood called 'white coal,' at one time used in the smelting of lead from the ore. Even old land usage can be deduced to some extent through examining the plants present, the form of trees, particular woodland boundary features, the presence or absence of coppicing, etc., etc. Some plants for instance have been known to linger on in one locality from the days of the monasteries and their 'physic' gardens.

Site visits and oral information
A visit is often essential, although satellite imagery can be a partial substitute. Local people rarely have a deep knowledge of their locality's history, however such information can be invaluable. It is often the case that site visits uncover the existence of primary sources of material such as photographs, deeds, etc. Additionally, personal contact with other local historians may result from meeting people local to an area.

Folklore, tradition and oral history
Many places have a rich folklore and tradition which can be both a help and a hindrance. Usually a kernel of truth is associated with such historical records, however they often suffer from exaggeration, fusion with other events, the 'Chinese whispers' phenomenon and other corruptions of historical accuracy. It is important for the researcher to remain impartial and often the simpler the version the more truth it holds.

False memory syndrome is a very real problem and questions to 'local' interviewees should be framed without any leading facts which could distort the correspondents memory at that time or later.

Selena's Tree is an example of how stories develop. This tree stands near Kilwinning in Ayrshire, Scotland. One legends records that it was the meeting place of lovers; a man from Eglinton castle and a woman from the town. A second legend records that it was where a local witch was burned at the stake. The first story is pure romantic fiction, the second confuses the site with the nearby place of execution where a witch was executed and the truth is that a local lady named Selena walked to this tree every day for many following a stroke at a relatively early age.

Sharing information and encouraging others
Wikipedia and Wikibook sites enable local historians to make their work available to a very wide audience, inviting the assistance and contributions of others. Contacting 'interested' individuals via email, post, etc. can widen the use of such Wiki sites and actively involve people in the recording of their own local history. Researchers in other countries often have an interest in work done by local historians, leading to productive communications and furtherance of objectives.

The writers of articles do not have any form of veto and it is inevitable that opinions will sometimes differ, resulting in edits which may or may not be a real improvement. Such is life! The important thing is to keep enthusiastic and pursue the Wikiway (democracy).

One great advantage of writing information on websites such as the various Wiki sites is that it will not get lost or corrupted by accident; it is a secure home therefore. A disadvantage, certainly on Wikipedia, is the less than perfect hard copy provided through the printing options.


text:
General Securities Representative Exam/Debt Securities

Debt Securities
Another method a corporation can raise capital is through Debt Securities which are also called bonds. Bonds are loans to the corporation made by the investor to be repaid at a stated future date at a set interest rate. Although, bonds are not limited to corporations. The U.S. government can issue government bonds. Also municipalities such as states, cities, and such can issue municipal bonds. Bonds can also be called funded debt, and are considered long term debt because they are usually issued for at least 5 years or more. Bonds are rated by Moody's, S & P and Fitch.

Each bond has a document or certificate that describes the terms and conditions of the loan. This document is called an indenture.

Some items to consider when investing in a bond are:

 * Reinvestment risk
 * Callable risk
 * Interest rate risk
 * Default risk

Convertible bonds are bonds that corporations issue that give the investor the right to convert the bonds to common stock.

A corporation can also issue commercial paper, which is generally traded overnight and used to shore up financing and cash, and has a maturity of less than 1 year.


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Talk:Korean/Lesson I2

에서
Why are we adding -에서 onto people in the exercises on the bottom of the page? —The preceding unsigned comment was added by Jeff23 (talk • contribs) 2007-09-06T18:38:07.

 * Good point, Jeff. You are right to note that 에서 is only supposed to be used with inanimate referents.  I suppose we could introduce 에게 or maybe just 게 in this lesson and change those exercises to have the student choose between 에서 and 에게 (or maybe 게), depending on the given noun.  Does that seem reasonable?  Rodasmith 00:33, 8 September 2007 (UTC)

"조새프"
I don't know if foreign word spelling rules have changed since last time I learned Korean, but I think Korean writing for "Joseph" is much closer to "죠셉" or "조셉" (in Korean Bible, it's actually written "요셉" which is actually more correct (i.e. closer to Hebrew pronunciation) than the ... bastardized English pronunciation). At the very least, it should definitely be "조세프", since "e" corresponds fairly well to "ㅔ" sound. novakyu (talk) 11:03, 24 December 2007 (UTC)

title: Talk:Korean/Lesson I2


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text: User:Julian Mendez

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Contemporary Educational Psychology/Chapter 13: The Reflective Practitioner/Action Research

Action Research: Hearing from Teachers about Improving Practice
Each of the professional articles just described offers ideas and recommendations that can stimulate reflection about teaching and learning. But they all suffer from a particular limitation: Although they often relate to teachers and classrooms, teachers’ role in influencing in designing and interpreting a study is minimal. In the world of educational research, persons other than teachers—typically professors, educational administrators, or other professional researchers—tend to speak on behalf of teachers. All three of the articles described earlier in this chapter had this feature. Persons other than teachers chose the research topics.

The information that emerges from this arrangement often still relates to teaching and learning, and may contain useful insights for classroom work. But by definition, it is framed by people whose interests and fundamental commitments may not be identical with classroom teachers. As a result, the studies are somewhat more likely to attend to problems posed by academic disciplines or by educational administrators. Two of the studies which we described earlier—the ones about moral development and about labels for disabilities—showed this quality. Classroom teachers are concerned, of course, about both moral development and categorizing of students. But if teachers had designed the two projects themselves, they might have reframed both of them to focus more explicitly on the challenges of classroom teaching. In studying moral beliefs, for example, teachers might have focused more squarely on how to foster moral beliefs in their students. In studying inclusive education, they might have focused more fully on the practical difficulties faced by teachers in assessing students’ learning disabilities with validity.

The Nature of Action Research
In view of these issues, a particularly important kind of investigation for teachers is action research (sometimes also teacher research), an activity referring to systematic, intentional inquiry by teachers for the purpose of improving their own practice (Stenhouse, 1985; Brydon-Miller, Greenwood, & Maguire, 2003; Russell, T. & Loughran, J. 2005). Action research is not to be confused with research about teaching and learning, which are investigations by professional researchers on topics of teachers, teaching, or learning.

Action research has several defining characteristics, in addition to being planned and conducted by teachers. First, it originates in the problems and dilemmas of classroom practice, or in chronic problems with certain students, materials, or activities. Second, its outcomes offer information focused on particular teachers and classrooms, rather than about teachers in general or students in general. Although this feature might make action research seem less useful as a source of advice or knowledge that is truly general, supporters argue that focusing on specific learning contexts makes action research more credible or valid as a source of practical information and ideas. It is, they argue, simply more attuned to the context of real classrooms (St. Clair, 2005). Third, while the audience for action research can certainly include professors and educational administrators, the audience tends to be other teachers (Fenstermacher, 1994; Ackerman & MacKenzie, 2007). Action research is therefore in an especially strong position to provide "insider" perspectives on educational problems.

Action Research in Practice
Action research makes a number of assumptions as a result of its nature and purposes (Richardson, 1994; Schmuck, 2006). To varying degrees, most such studies support some combination of these ideas:
 * 1) that teaching is itself really a form of research,
 * 2) that action research, like teaching itself, requires substantial reflection,
 * 3) that collaboration among teachers is crucial for making teacher research meaningful, and for the improvement of teaching, and
 * 4) that teachers' knowledge of teaching has to be shared publicly, especially when gained systematically through action research.

To see how these features look in practice, look at several examples of action research studies.

Example #1: Focusing on Motivating Students
A number of years ago, Patricia Clifford and Sharon Friesen published an account of their effort to develop a classroom program based on students' out-of-school interests and experiences (1993). Clifford and Friesen were co-teachers in a double-sized classroom which deliberately included children from first-, second-, and third-grades. Their interest in students’ out-of-school experiences grew out of three more basic questions about teaching, which they phrased like this:

 * How can curriculum remain open to children's unique experiences and connect with the world they know outside the school? Too often, the official school curriculum lacked meaning for children because it seemed cut off from the rest of the world.  The result was unmotivated students and poor learning.
 * Why is imaginative experience the best starting place for planning? The teachers felt that imaginative experiences—make-believe play, stories, poems—provided access to children's lives outside school—their make-believe play, or their stories or poems.  Perhaps somehow these could be connected to the goals of the official curriculum.
 * What happens when teachers break down the barriers between school knowledge and real knowledge? In drawing on children's outside experiences, would children actually become more motivated or not?  Would they take over the program, and fail to learn the official curriculum goals?

To answer these questions, the teachers kept extensive diaries or journals for one entire school year. These became the “data” for the research. In the journals, they described and reflected on their daily teaching experiences. The teachers also talked with each other extensively about classroom events and their significance, and the results of the conversations often entered the journals eventually during the research. In their journal, for example, the teachers recorded an experience with students about ways of telling time. In preliminary discussions the students became interested in how a sundial worked. So the teachers and students went outside, where they created a human sundial, using the students themselves. The teachers' journal kept a chronicle of these events, and noted the comments and questions which students developed as a result:

 * - If you stood in the same place for a whole day you would see your shadow change places because the earth changes position;

 * - Why is my shadow longer than I am in the evening, but shorter at noon?

 * - Clouds can block the sun's rays so sundials won't work on rainy days;

 * - How did people start to tell time?

As the year evolved and observations accumulated and were recorded, the teachers gradually did begin to answer their own three questions. They found, for example, that connecting the curriculum with children's interests and motives was most effective when they could establish a personal bond with a child. They also found that imaginative expression helped certain children to feel safe to explore ideas. And they found that blending school-based and personal knowledge caused children to learn much more than before—although much of the additional knowledge was not part of an official curriculum. With these conclusions in mind, and with numerous examples to support them, Clifford and Friesen published their study so that others could share what they had learned about teaching, learning, and students.

The study by Clifford and Friesen is interesting in its own right, but for our purposes think for a moment about their work as an example of action research. One of its features is that it formed part of the normal course of teaching: the authors were simply more systematic about how they observed the students and recorded information about classroom events. Another feature is that the research required conscious reflection over an extended time: their journals and conversations contained not only descriptions of events, but also interpretations of the events. A third feature is that the study involved collaboration: it was not just one teacher studying the major questions, but two. And a fourth is that the teachers not only developed their results and conclusions for themselves, but also shared them with others. These four qualities make the study by Clifford and Friesen a clear example of teacher research. Note, though, that sometimes studies conducted by teachers may not show all of these features so clearly; instead they may show some of the key features, but not all of them, as in the next two examples.

Example #2: Focusing on Development
Since 1981, Vivian Paley has published a series of short books documenting and interpreting her observations of young children in classrooms (1981, 1986, 1991, 1998, 2000, 2005). Paley was interested in how young children develop or change over the long term, and in particular how the development looks from the point of view of a classroom teacher. In one of these books, for example, she observed one child in particular, Mollie, from the time she entered nursery school just after her third birthday until after the child turned four years old. Her interest was not focused on curriculum, as Clifford and Friesen's had done, but on Mollie as a growing human being; "the subject which I most wished to learn," she wrote, "is children" (p. xiv). Paley therefore wrote extended narrative (or story-like) observations about the whole range of activities of this one child, and wove in periodic brief reflections on the observations. Because the observations took story-like form, her books read a bit like novels: themes are sometimes simply suggested by the story line, rather than stated explicitly. Using this approach, Paley demonstrated (but occasionally also stated) several important developmental changes. In Mollie Is Three (1988), for example, she describes examples of Mollie's language development. At three years, the language was often disconnected from Mollie’s actions—she would talk about one thing, but do another. By four, she was much more likely to tie language to her current activities, and in this sense she more often "said what she meant." A result of the change was that Mollie also began understanding and following classroom rules as the year went on, because the language of rules became more connected in her mind to the actions to which they referred.

Vivian Paley's book had some of the characteristics of action research—but with differences from Clifford and Friesen’s. Like their research, Paley's “data” was based on her own teaching, while her teaching was influenced in turn by her systematic observations. And like Clifford and Friesen’s, Paley’s research involved numerous reflections on teaching, and it led to a public sharing of the reflections—in this case in the form of several small books. Unlike Clifford and Friesen, though, Paley worked independently, without collaboration. And unlike Clifford and Friesen, she deliberately integrated observation and interpretation as they might be integrated in a piece of fiction, so that the resulting "story" often implied or showed its message without stating it in so may words. In this regard her work had qualities of what some educators call arts-based research, which are studies that take advantage of an artistic medium (in this case, narrative or story-like writing) to heighten readers' understanding and response to research findings (Barone and Eisner, 2006). If you are studying the use of space in the classroom, for example, then aesthetically organized visual depictions (photos, drawings) of the room may be more helpful and create more understanding than verbal descriptions. If you are studying children's musical knowledge, on the other hand, recordings of performances by the children may be more helpful and informative than discussions of performances.

Example #3: Focusing on Collaboration
In 1996, an example of action research was published that was intended simultaneously for classroom teachers and for university researchers, and which focused on the challenges of collaboration among educators (Ulichny & Schoener, 1996). A teacher (Wendy Schoener) and a university researcher (Polly Ulichny) explored how, or even whether, teachers and university researchers could participate as equals in the study of teaching. Wendy (the two used first names throughout when they published their experiences) was a teacher of adults learning English as a Second Language (ESL); Polly was a specialist in multicultural education and wanted to observe a teacher who was successful at reaching the ethnically diverse students who normally study ESL. Polly therefore asked Wendy for permission to study her teaching for an extended period of time—to visit her class, videotape it, interview her about it, and the like.

What followed is best described as an extended negotiation between teacher and professor for access to Wendy's class, on the one hand, and for mutual respect for each other's work, on the other. In the published article, the negotiations are described separately by each participant, in order to honor the differences in their concerns and perspectives. Before, during, and after the observations, it was necessary for Polly and Wendy each to adjust expectations of what the other person could do and was willing to do. As the authors put it, some things were "easy to hear" from the other and some things were "hard to hear." Wendy, as a teacher, found it easier to hear criticisms of her teaching if they came from herself, rather than from the higher-status university professor, Polly. Polly, for her part, found it easier to hear Wendy's comments if she matched Wendy's self-criticisms and evaluations with some of her own experiences. Polly therefore made sure to tell Wendy about dilemmas and problems she experienced in her own (university) teaching. Because they needed to adjust to hearing and talking with each other, the two educators eventually focused less on Polly's original purpose—studying multicultural teaching—and more on the problem of how teachers and university researchers might collaborate effectively.

Overall, this study qualifies as a piece of action research, though it is not fully focused on classroom teaching. For example, the teachers did collaborate and reflect on their experiences, but not all of the reflection was about teaching in classrooms. The rest was about the relationship between Wendy and Polly. While the problem selected was originally about classroom teaching—Wendy’s—it did not originate with the classroom teacher (Wendy) or concerns she had about her own classroom; instead it was chosen by the university researcher (Polly) and her desire to study multicultural teaching. The researchers did share what they learned by publishing their observations and ideas, but their published report speaks only partly to classroom teachers as such; in addition it speaks to academic researchers and educators of future teachers.

By pointing out differences among these examples of action research, we do not mean to imply that one is “better” than another. The point is simply to show how diverse studies by teachers can be, and to appreciate their differences. Whatever their specific features, classroom studies by teachers hold in common is a commitment to giving a voice to teachers as they reflect on problems and challenges intrinsic to classroom life. This goal can be accomplished in more than one way: through journals and other record-keeping methods, through oral discussions with colleagues, and through written reflections created either for themselves or for others concerned about teaching and learning. Diversity among topics and methods in action research studies should not surprise us, in fact, since classrooms are themselves so diverse.

(back to Chapter 13...)


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CAT-Tools/SDL Trados/Workarounds

Tag Editor
Set/Close Next no 100% Open/Get

Problem: Set/Close Next no 100% Open/Get is supposed to go through TUs until a TU that is not a 100% perfect match is found. Instead, though, it sometimes stops at each TU even if it is a 100% match.

Solutions:
 * 1) If the concordance window (Workbench) is open, try closing it.
 * 2) Try reorganizing the TM

title: CAT-Tools/SDL Trados/Workarounds


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Contemporary Educational Psychology/Chapter 13: The Reflective Practitioner/Cautions and Challenges of Action Research

Well and good, you may say. Action research offers teachers a way to hear each other, to learn from their own and other's experience. But there are also a few cautions to keep in mind, both ethical and practical. Look briefly at each of these areas.

Ethical Cautions about Action Research
One caution is the possibility of conflict of interest between the roles of teaching and conducting action research (Hammack, 1997). A teacher’s first priorities should be the welfare of his or her students: first and foremost, you want students to learn, to be motivated, to feel accepted by their peers, and the like. A researcher’s first priorities, however, are to the field or topic being studied. The two kinds of priorities may often overlap and support each other. Vivian Paley’s observations of children in her classes, described earlier, not only supported her children’s learning, but also her studies of the children.

But situations can also occur in which action research and teaching are less compatible, and can create which ethical dilemmas. The problems usually relate to one of three issues: privacy, informed consent, or freedom to participate. Each of these becomes an issue only if the results of a research project are made public, either in a journal or book, as with the examples we have given in this chapter, or simply by being described or shared outside the classroom. (Sharing, you may recall, is one of the defining features of action research.) Look briefly at each of the issues.

Insuring Privacy of the Student
Teachers often learn information about students that the students or their families may not want publicized. Suppose, for example, you have a student with an intellectual disability in your class, and you wish to study how the student learns. Observing the student work on (and possibly struggle with) academic activities may be quite consistent with a teacher’s responsibilities; after all, teachers normally should pay attention to their students’ academic efforts. But the student or his family may not want such observations publicized or even shared informally with other parents or teachers. They may feel that doing so would risk stigmatizing the student publicly.

To respect the student’s privacy and still study his learning behavior, the teacher (alias the “action researcher”) therefore needs to disguise the student’s identity whenever the research results are made public. In any written or oral report, or even in any hallway conversation about the project, the teacher/researcher would use a pseudonym for the student, and change other identifying information such as the physical description of the student or even the student’s gender. There are limits, however, to how much can be disguised without changing essential information. The teacher could not, for example, hide the fact of the intellectual disability without compromising the point of the study; yet the intellectual disability might be unusual enough that it would effectively identify the student being studied.

Gaining Informed Consent
Students may not understand what is being studied about them, or even realize that they are being studied at all, unless the teacher/researcher makes an explicit effort to inform them about the action research and how she will use the results from it. The same is true for the students’ parents; unless the teacher-researcher makes an effort to contact parents, they simply will not know that their child’s activities are being observed or may eventually be made public. Students’ ignorance is especially likely if the students are very young (kindergarten) or have intellectual or reading difficulties, as in the example we described above. As an action researcher, therefore, a teacher is obliged to explain the nature of a research project clearly, either in a letter written in simple language or in a face-to-face conversation, or both. Parents and students need to give clear indications that they actually understand what class activities or materials will constitute data that could be made public. In most cases, indicating informed consent boils down to students’ parents signing a letter giving permission for the study. Sometimes, in addition, it is a good idea to recheck with students or parents periodically as the project unfolds, to make sure that they still support participation.

Insuring Freedom to Participate
When a student fails to participate in an ordinary class activity, most teachers consider it legitimate to insist on the student’s participation—either by persuading, demanding, or (perhaps) tricking the student to join in. Doing so is ethical for teachers in their roles as teachers, because teachers are primarily responsible for insuring that students learn, and students’ participation presumably facilitates learning. If a teacher designates an activity as part of an action research project, however, and later shares the results with them, the teacher then also becomes partly responsible for how other teachers use knowledge of the research study. (Remember: sharing results is intrinsically part of the research process.) The resulting dual commitment means that “forcing” a student to participate in an action research activity can no longer be justified solely as being for the student’s own educational good.

Much of the time, a simultaneous commitment to both teachers and students presents no real dilemma: what is good for the action research project may also be good for the students. But not always. Suppose, for example, that a teacher wants to do research about students’ beliefs about war and global conflict, and doing so requires that students participate in numerous extended group discussions on this topic. Even though the group discussions might resemble a social studies lesson and in this sense be generally acceptable as a class activity, some parents (or students) may object because they take too much class time away from the normal curriculum topics. Yet the research project necessitates giving it lots of discussion time in class. To respond ethically to this dilemma, therefore, the teacher may need to allow students to opt out of the discussions if they or their parents choose. She may therefore need to find ways for them to cover an alternate set of activities from the curriculum. (One way to do this, for example, is to hold the special group discussions outside regular class times—though this obviously also increases the amount of work for both the teacher and students.)

Practical Challenges about Action Research
Is action research practical? From one perspective the answer has to be "Of course not!” Action research is not practical because it may take teachers’ time and effort which they could sometimes use in other ways.  Keep in mind, though, that a major part of the effort needed for action research involves the same sort of work—observing, recording information, reflecting—that is needed for any teaching that is done well. A better way to assess practicality may therefore be to recognize that teaching students always takes a lot of work, and to ask whether the additional thoughtfulness brought on by action research will make the teaching more successful.

Looked at in this way, action research is indeed practical, though probably not equally so on every occasion. If you choose to learn about the quality of conversational exchanges between yourself and students, for example, you will need some way to record these dialogues, or at least to keep accurate, detailed notes on them. Recording the dialogues may be practical and beneficial—or not, depending on your circumstances. On the other hand, if you choose to study how and why certain students remain on the margins of your class socially, this problem too may be practical as action research. Or it may not, depending on whether you can find a way to observe and reflect on students' social interactions, or lack thereof. Much depends on your circumstances—on the attention you can afford to give to your research problem while teaching, in relation to the benefits that solutions to the problems will bring students later. In general any action research project may require certain choices about how to teach, though it should not interfere with basic instructional goals or prevent coverage of an important curriculum. The main point to remember is that action research is more than passive observation of students and classrooms; it also includes educational interventions, efforts to stimulate students to new thinking and new responses. Those are features of regular teaching; the difference is primarily in how systematically and reflectively you do them.

(back to Chapter 13...)


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Talk:FHSST Computer Literacy/Contents

Might find this interesting: http://en.wikipedia.org/w/index.php?title=Netiquette&oldid=156111571 If OR's fair game here, feel free to use the above. It didn't fit the Wikipedia guidelines, but warrants some consideration as a source of free material when fleshing out part 3 of this outline. Let me know if you need any help with the book in general, 72.129.175.232 19:47, 6 September 2007 (UTC) wikipedia::User:Mrzaius

title: Talk:FHSST Computer Literacy/Contents


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User:DavidJoyner

David Joyner
* Mathematics Prof at USNA

* Work webpage: http://cadigweb.ew.usna.edu/%7Ewdj/homepage.html * Personal webpage: http://www.wdjoyner.com/

* The material I write is licensed under the Attribution-ShareAlike Creative Commons license or the GNU Free Documentation License (your choice). For details, see http://creativecommons.org/about/licenses/meet-the-licenses and http://www.gnu.org/licenses/.

title: User:DavidJoyner


text: Category:Subject:Firmware

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Blender 3D: Noob to Pro/Modeling a Mug using Spinning and Extrusion

Start by deleting the default cube. In front view, Add a circle. Move the vertices around to form a backwards "L" shape. Select the vertex on the bottom left and go to Mesh-snap-cursor to selection. Then, in top view, select all the vertices and spin it 360 degrees. Then, select all verticies, hit wkey, and click remove doubles. Then, on one of the sides, select the middle face. Extrude it 0.7, and make an fgon with the three triangles on the side of the main part. Select the two squares on the top of the extrusion and extrude them to 1.82. then subdivide the inner part of the handle. Select the middle edges and move them up. Extrude the faces above into the base. Position the camera and add a level three light source. Render the model. You can add color, texture, or anything else.


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User:Dantheman531

See my user page on the English Wikipedia.

title: User:Dantheman531


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User talk:Dantheman531

See my user talk page on the English Wikipedia.

title: User talk:Dantheman531


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Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nf6/5. O-O/5...Nxe4/6. d4/6...b5/7. d5

=Ruy Lopez Open Defence=

Black has no need to tie herself in knots by moving the knight. After 7...bxa4 8. dxc6 d6, forget about Black's potentially slightly rubbish rook pawns, one of which is an extra pawn anyway - Black has a stable centre with the base of her pawn-chain shielded by White's own pawn, a half-open b-file, a kingside pawn majority that could quite easily wallop White after ...f5 and ...Nf6 and the bishop pair - it's one of those rare positions that are just really good fun.


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User:Severo

w:User:Severo

 * My previous Wikipedia login was User:Mk3severo, which appears once in WikiBooks due to article moving from Wikipedia.

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User talk:Severo

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text: Talk:C++ Programming/Programming Languages/C++


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text: Subject:Biomedical engineering

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text: Subject:Chemical engineering

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text: Category:Book:Introduction to Chemical Engineering Processes


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Introduction to Chemical Engineering Processes/Significant figures

Importance of Significant Figures
Significant figures (also called significant digits) are an important part of scientific and mathematical calculations, and deals with the accuracy and precision of numbers. It is important to estimate uncertainty in the final result, and this is where significant figures become very important.

Precision and Accuracy
Before discussing how to deal with significant figures one should discuss what precision and accuracy in relation to chemical experiments and engineering are. Precision refers to the reproducibility of results and measurements in an experiment, while accuracy refers to how close the value is to the actual or true value. Results can be both precise and accurate, neither precise nor accurate, precise and not accurate, or vice versa. The validity of the results increases as they are more accurate and precise.

A useful analogy that helps distinguish the difference between accuracy and precision is the use of a target. The bullseye of the target represents the true value, while the holes made by each shot (each trial) represents the validity. As the above images show, the first has a lot of holes (black spots) covering a small area. The small area represents a precise experiment, yet it seems that there is a faultiness within the experiment, most likely due to systematic error, rather than random error. The second image represents an accurate though imprecise experiment. The holes are near the bullseye, even "touching" or within, though the problem is that they are spread out. This could be due to random error, systematic error, or not being careful in measuring.

Counting Significant Figures
There are three preliminary rules to counting significant. They deal with non-zero numbers, zeros, and exact numbers.

1) Non-zero numbers - all non-zero numbers are considered significant figures

2) Zeros - there are three different types of zeros
 * leading zeros - zeros that precede digits - do not count as significant figures (example: .0002 has one significant figure)
 * captive zeros - zeros that are "caught" between two digits - do count as significant figures (example: 101.205 has six significant figures)
 * trailing zeros - zeros that are at the end of a string of numbers and zeros - only count if there is a decimal place (example: 100 has one significant figure, while 1.00, as well as 100., has three)

3) Exact numbers - these are numbers not obtained by measurements, and are determined by counting. An example of this is if one counted the number of millimetres in a centimetre (10 - it is the definition of a millimetre), but another example would be if you have 3 apples.

The Parable of the Cement Block
People new to the field often question the importance of significant figures, but they have great practical importance, for they are a quick way to tell how precise a number is. Including too many can not only make your numbers harder to read, it can also have serious negative consequences.

As an anecdote, consider two engineers who work for a construction company. They need to order cement bricks for a certain project. They have to build a wall that is 10 feet wide, and plan to lay the base with 30 bricks. The first engineer does not consider the importance of significant figures and calculates that the bricks need to be 0.3333 feet wide and the second does and reports the number as 0.33, figuring that a precision of $$ \pm 0.01ft $$ (0.1 inches) would be precise enough for the work she was doing.

Now, when the cement company received the orders from the first engineer, they had a great deal of trouble. Their machines were precise but not so precise that they could consistently cut to within 0.0001 feet. However, after a good deal of trial and error and testing, and some waste from products that did not meet the specification, they finally machined all of the bricks that were needed. The other engineer's orders were much easier, and generated minimal waste.

When the engineers received the bills, they compared the bill for the services, and the first one was shocked at how expensive hers was. When they consulted with the company, the company explained the situation: they needed such a high precision for the first order that they required significant extra labor to meet the specification, as well as some extra material. Therefore it was much more costly to produce.

What is the point of this story? Significant figures matter. It is important to have a reasonable gauge of how precise a number is so that you know not only what the number is but how much you can trust it and how limited it is. The engineer will have to make decisions about how precisely he or she needs to specify design specifications, and how precise measurement instruments (and control systems!) have to be. If you do not need 99.9999% purity then you probably don't need an expensive assay to detect generic impurities at a 0.0001% level (though the lab technicians will probably have to still test for heavy metals and such), and likewise you will not have to design nearly as large of a distillation column to achieve the separations necessary for such a high purity.

Mathematical Operations and Significant Figures
Most likely at one point, the numbers obtained in one's measurements will be used within mathematical operations. What does one do if each number has a different amount of significant figures? If one adds 2.0 litres of liquid with 1.000252 litres, how much does one have afterwards? What would 2.45 times 223.5 get?

For addition and subtraction, the result has the same number of decimal places as the least precise measurement use in the calculation. This means that 112.420020 + 5.2105231 + 1.4 would have have a single decimal place but there can be any amount of numbers to the left of the decimal point (in this case the answer is 119.0).

For multiplication and division, the number that is the least precise measurement, or the number of digits. This means that 2.499 is more precise than 2.7, since the former has four digits while the latter has two. This means that 5.000 divided by 2.5 (both being measurements of some kind) would lead to an answer of 2.0.

Rounding
So now you know how to pick which numbers to drop if there is a question about significant figures, but one also has to take into account rounding. Once one has decided which digit should be the last digit kept, one must decide whether to round up or down.

 * If the number is greater than five (6 to 9), one rounds up - 1.36 becomes 1.4

What does one do when there is a five? There is a special case that deals with the number five, since, if you have not noticed, it is in the middle (between 1 and 9). Often in primary school one learns to just round up, but engineers tend to do something different, called unbiased rounding.
 * If the number is less than five (1 to 4), one rounds down - 1.34 becomes 1.3

 * If the number before the five is even, then one rounds down - 1.45 becomes 1.4

 * If the number before the five is odd, then one rounds up - 1.55 becomes 1.6

 * Another case is this: 1.4501, where the numbers after five are greater than zero, so one would round to 1.5

Note: Remember that rounding is generally done at the end of calculations, not before the calculations are made.

Why is this done? Engineers make many calculations that often matter, since time, money, etc. are being taken into account, it is best to make sure that the final results are not synthetic or untrue to what the actual value should be. This relates back to accuracy and precision.


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Introduction to Chemical Engineering Processes/General chemistry review

Stoichiometry
Le Système International d'Unités (SI Units)

Mole
The mole is a measure of the amount of substance. A mole is the amount of material which contains the same number of elementary entities as there are atoms in 12g of Carbon-12.

There are Avogadro number of atoms in 12g of Carbon-12, i.e. 6.023 x 10^23 atoms.

Thus a mole of cars implies there are 6.023 x 10^23 cars and so on.

Acid-Base
There are two major ways to classify acids and bases: the Brønsted-Lowry definition, and the Lewis definition. A chemical species that donates protons is a Brønsted-Lowry acid, and a species that accepts protons is a Brønsted-Lowry base. Typically, the proton is written as an H+ ion, though they do not in isolation exist in solution and are instead exchanged between molecules. In water, the proton on an acid will often bond to the H2O molecules to form the conjugate base and H3O+ (hydronium) ions, and the proton-accepting base will take an H+ from the water to form the conjugate acid and OH- (hydroxide) ions. This is the most familiar situation for those who have taken general chemistry, but any species that loses an H+ (proton) to another molecule is considered a Brønsted-Lowry acid, and likewise any H+-taking species is considered a Brønsted-Lowry base.

The second and broader classification is the Lewis acids and bases. Lewis acids and bases are defined by their electron lone pair behavior. A Lewis acid is an electron acceptor (called an electrophile in organic chemistry), a Lewis base is an electron donor (a nucleophile in organic chemistry). In a Lewis acid-base reaction, the negatively charged electron lone pair in the base will bond to the positive or partially positive segment of the acid to form what is called a Lewis adduct. Unlike Brønsted-Lowry acids and bases, the exchange of protons is not required.

Ideal Gas Law
$$PV = nRT$$

P = Pressure; V = Volume; n = moles; R = Ideal gas constant; T = Temperature

Enthalpy
The enthalpy content of a substance is given by

\hat{H} = U + pV

where

H is the enthalpy (SI units: J/kg) U is the internal energy and p is the pressure V is the volume

Branches of Chemistry

 * Inorganic Chemistry - The study of the synthesis and behavior of inorganic and organometallic compounds. This field covers all chemical compounds except the myriad organic compounds.
 * Organic Chemistry - The study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.
 * Physical Chemistry - The study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of laws and concepts of physics. It applies the principles, practices and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics and dynamics, equilibrium.
 * Analytical Chemistry -
 * Biochemistry -
 * Organometallic chemistry -


text:
Introduction to Chemical Engineering Processes/Generalized Correlations

Critical Constants
At room temperature (about 298K), it is possible to add enough pressure to carbon dioxide to get it to liquify (some fire extinguishers work by keeping liquid carbon dioxide in them under very high pressure, which rapidly vaporizes when the pressure is relieved . However, if the temperature is raised to higher than 304.2 K, it will be impossible to keep carbon dioxide in a liquid form, because it has too much kinetic energy to remain in the liquid phase. No amount of pressure can turn carbon dioxide into a liquid if the temperature is too high.

This threshold temperature is called a critical temperature. Any pure stable substance (not just carbon dioxide) will have a single characteristic critical temperature. Pure stable substances will also have a single characteristic critical pressure, which is the pressure needed to achieve a phase transition at the critical temperature, and a critical specific volume which is the specific volume (volume per mass) of the fluid at this temperature and pressure.

Critical pressures are typically extremely large, ranging from 2.26 atm for helium to 218.3 atm for water, and about 40 atm on average. Critical temperatures typically range from 5.26 K (for helium) to the high 600s K for some aromatic compounds.

A substance which is at a temperature higher than the critical temperature and a pressure higher than its critical pressure is called a supercritical fluid. Supercritical fluids have some properties in common with gasses and some in common with liquid, as may be expected since it they are not observed to be liquid but would be expected to be liquefied at extreme pressures.

Law of Corresponding States
Recall from the last section that the compressibility of any substance (but most useful for gasses) is defined as:

$$ Z=\frac{P*\hat{V}}{RT} $$

The compressibility of a gas is a measure of how non-ideal it is; an ideal gas has a compressibility of 1. At the critical point, in particular, the compressibility is:

Critical constants are important because it has been found experimentally that the following rule is true for many substances:

It has been found experimentally that many substances have very similar compressibility at their critical point. . Most nonpolar substances in particular have a critical compressibility of about 0.27. The similarity of the critical compressibility between substances is what gives some weight to the law of corresponding states. However, the fact that the critical compressibility is not exactly the same for all substances leads to potential estimation errors if this method is used.

The critical constants are able to effectively predict the properties of a substance without gathering a large amount of data. However, it is necessary to define how the properties of the substance change as the system variables become closer to or farther from the critical point of the substance. These methods are discussed in the following sections.

Compressibility Charts
Recall that many substances have similar critical compressibility values near 0.27. Therefore, charts have been developed which relate compressibility at other conditions to those at the critical point. In order to use these charts, the system parameters are normalized by dividing by the critical constants to yield reduced temperature, pressure, and volume:


text: Introduction to Chemical Engineering Processes/Solving problems


text:
Introduction to Chemical Engineering Processes/Unusual Units

Standard vs. Actual Volume
When specifying the volume of a gas, the pressure and temperature must be specified because the volume of a gas depends strongly on both temperature and pressure (assuming that it is in an expandable container). In order to avoid specifying a different set of conditions for each measurement, an engineer can convert to standard temperature and pressure (typically 1 atm and 0oC) which is common to all measurements. This allows direct comparisons of volume measurements, but also requires that one convert back to the actual conditions present in the system before the value can be used.

The conversion that is used assumes that the gas is ideal, so that:

$$ PV = nRT $$

Conversion of volume to volume
We wish to compare a standard state to the actual state in the system. Let us consider the standard state (state "s") first. We have the ideal gas law for the standard state:

$$ P_s*V_s = n_sRT_s $$

Now let us compare the standard state to the actual conditions in the system. The standard state conditions have been completely specified. The ideal gas law is assumed to hold in the actual system conditions as well:

$$ P_aV_a = n_aRT_a $$

Divide this equation by the standard-state ideal gas law gives:

$$ \frac{P_aV_a}{P_s{V}_s} = \frac{n_aRT_a}{n_sRT_s} $$

where a is actual and s is standard. If we assume that we want to compare the same number of moles of the substance between the standard and actual states, the following conversion between the states is obtained:


text: Subject:Environmental engineering

title: Subject:Environmental engineering


text: Subject:Nuclear engineering

title: Subject:Nuclear engineering


text: Subject:Software engineering

title: Subject:Software engineering


text: Category:Book:Computer Systems Engineering


text: Category:Book:Fluid Mechanics

title: Category:Book:Fluid Mechanics


text: Category:Book:Engineering Mechanics

title: Category:Book:Engineering Mechanics


text: Subject:Geotechnical engineering

title: Subject:Geotechnical engineering


text:
Digital Signal Processing/Resources

Wikimedia Resources

 * Reaktor
 * Programming:MATLAB
 * Octave Programming
 * Control Systems
 * Signals and Systems
 * Engineering Analysis
 * Digital Signal Processing

Books

 * Lathi, B. P, Signal Processing and Linear Systems, Oxford University Press, 1998. ISBN 0195219171
 * Mitra, Sanjit K, Digital Signal Processing: A Computer-Based Approach, McGraw Hill, 2006. ISBN 0072865466
 * Haykin, Simon, Adaptive Filter Theory', Fourth Edition, Prentice Hall, 2002. ISBN 0130901261

title: Digital Signal Processing/Resources


text:
Digital Signal Processing/Licensing

License
The text of this book is released under the following license:

title: Digital Signal Processing/Licensing


text:
User talk:67.171.53.48

Thanks for experimenting with the page Statistics/Different Types of Data/Quantitative and Qualitative Data on Wikibooks. Your test worked, and has been reverted or removed. Please use the sandbox for any other tests you want to do. Take a look at the welcome page if you would like to learn more about contributing to our project. Thanks.

Az1568(Talk) 05:14, 7 September 2007 (UTC)

title: User talk:67.171.53.48


text:
User:Natsubee

I am usually on the English Wikipedia here but hope to start contributing here.

title: User:Natsubee


text:
Talk:Muggles' Guide to Harry Potter/Magic/Deluminator

I have to dispute the bit in the Extended Description when it talks about how it worked for Ron in the 7th book. It doesn't act like a Portkey, and it doesn't track the other two. It doesn't work like that at all. -58.175.33.120 09:19, 7 September 2007 (UTC)
 * It does seem to provide a transport portal of some sort, though. Let me see if I can figure out how to word that. Chazz (talk) 17:58, 7 September 2007 (UTC)
 * Better? Chazz (talk) 18:29, 7 September 2007 (UTC)


text:
User:Cygnis insignis

/Nature printing

title: User:Cygnis insignis


text:
User talk:24.56.251.6

Thanks for experimenting with Wikibooks. Your test worked, and has now been removed. Please use Sandbox for any other tests you want to do, since testing material in modules will normally be removed quickly. Please see the welcome page if you would like to learn more about contributing to our project. Thanks. – Mike.lifeguard  | talk 14:26, 7 September 2007 (UTC)

title: User talk:24.56.251.6


text:
User talk:85.18.14.27

 – Mike.lifeguard  | talk 14:27, 7 September 2007 (UTC)

title: User talk:85.18.14.27


text:
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Bxc6/4...dxc6/5. Nxe5

= Ruy Lopez, Exchange Variation = This is a poor move as Qd4 forks the knight at e5 and the pawn at e4. This gives Black control of the centre and an opportunity to do some further damage...

The knight retreats to f3 or d3 leading to Qxe4! and checks the King any defence means losing the opportunity to castle. Instead White can play 6. Ng4 but 6...Qxe4+ 7 Ne3 still leaves Black ahead in development and with the bishop pair.


text:
User talk:91.84.143.82

 – Mike.lifeguard  | talk 15:40, 7 September 2007 (UTC)

title: User talk:91.84.143.82


text:
User talk:Bobo5467

Please do not remove large amounts of content without good reason; this is considered vandalism, and you will be blocked if you continue to make such edits. The edits have been reverted; please do not make them again without prior discussion on the relevant talk pages.  – Mike.lifeguard  | talk 15:46, 7 September 2007 (UTC)

 * If you remove further material without explanation an admin will probably block you - removals must be explained, thanks -- Herby talk thyme 15:54, 7 September 2007 (UTC)

title: User talk:Bobo5467


text:
User talk:ThreeE

Do you have the entire Chess Opening Theory book on your watchlist? It's often very difficult to tell if an edit is valid or not since (although I play chess), the notation seems highly esoteric. Since you're more likely to know if an edit is good or not, if you could help out the RC-watchers by patrolling this book for bad edits, it'd be appreciated. Thanks!  – Mike.lifeguard  | talk 16:06, 7 September 2007 (UTC)
 * I think I have most of it yes. I'll keep an eye out as best I can.  Thanks! ThreeE 22:09, 22 September 2007 (UTC)

=hello= Been working on the theory pages the last few days. You might like to check some of it out, especially Two Knights defence. E5ricky 22:40, 21 October 2007 (UTC)
 * Very nice -- always good to see new contributions! ThreeE 00:15, 2 December 2007 (UTC)

title: User talk:ThreeE


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User:Whiteknight/Simple Subject

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User talk:Ssmar002

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. --dark lama  17:09, 7 September 2007 (UTC)

title: User talk:Ssmar002


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User talk:Ccarte037

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 17:15, 7 September 2007 (UTC)

title: User talk:Ccarte037


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User talk:Awill118

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title: User talk:Awill118


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User talk:Mhanc006

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User talk:Abeas001

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title: User talk:Abeas001


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User talk:Slboyd

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title: User talk:Slboyd


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User talk:AngelaBartle

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title: User talk:AngelaBartle


text:
User talk:164.106.201.53

 – Mike.lifeguard  | talk 17:17, 7 September 2007 (UTC)

title: User talk:164.106.201.53


text:
Subject:Science

自然科学 ko:위키책:자연과학

title: Subject:Science


text:
Subject:Physics

de:Regal:Physik Física fa:موضوع:فیزیک Physique Fysica 物理学 Física

title: Subject:Physics


text:
Subject:Chemistry

de:Regal:Chemie 化学

title: Subject:Chemistry


text:
Subject:Biology

de:Regal:Biologie 生物学 nl:Portaal:Biologie

title: Subject:Biology


text:
Subject:Earth sciences

de:Regal:Geowissenschaften 地球科学

title: Subject:Earth sciences


text:
Subject:Environmental sciences

地球環境科学

title: Subject:Environmental sciences


text: Category:Book:Carbon Nanotube Cookbook

title: Category:Book:Carbon Nanotube Cookbook


text: Template:BookCat

title: Template:BookCat


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User talk:Ablan010

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title: User talk:Ablan010


text:
User talk:XN73Q/A

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 18:33, 7 September 2007 (UTC)

I did reply on my talk page; please make sure you add it to your watchlist to see when I've replied.  – Mike.lifeguard  | talk 20:23, 7 September 2007 (UTC)
 * Thank you. --Harris Morgan 22:14, 7 September 2007 (UTC)

title: User talk:XN73Q/A


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User talk:Netspin

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text:
Category:Book:Organic Chemistry

pt:Categoria:Química Orgânica

title: Category:Book:Organic Chemistry


text:
User talk:Abibb001

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 18:43, 7 September 2007 (UTC)

Hello! I was also an Applied Math major while at Norfolk State! I'm excited to see another mathematician! With your background, I'm sure you will have plenty to give to your students. You have a beautiful family by the way! Scopp001 (talk) 00:37, 13 September 2008 (UTC)

I commend you for deciding to teach math. I have always struggled through math classes, but with hard work managed to keep good grades. For me I always had a hard time understanding why a problem was worked the way it was, what purpose it actually served, and it just never really made sense to me. It would have helped me to have teachers in highschool with such a strong, outlined plan for teaching. It sounds like with your disciplined military background, focus, and love of math you will make an excellent high school teacher. Aburk018 (talk) 17:57, 14 September 2008 (UTC)

title: User talk:Abibb001


text: Category:Book:General Chemistry

title: Category:Book:General Chemistry


text:
GtkRadiant/The Walls

Now that you have done the floor (which I hope you have by now) it's time to move on to another important feature of the room; the walls. You should be able to move and resize brushes by now, so I wont explain that step by step. Anyway, start by making a brush at the side of the edge of the floor brush, it should be one grid snap thick and also be one snap outside the floor brush, not so far that there is a gap, just so far that it touches the floor brush with its edge. You may have to switch view (CTRL+TAB) to move the brush in the correct position. Just make sure your brush does not overlap another brush, as this usually leads to map issues and longer compile times.

After one of the brushes is correctly positioned, you can just duplicate the brush (SPACE) and rotate it round the Z-axis by clicking the button. Remember to duplicate the brush before you rotate it. Repeat this step once for each wall, so once you have placed the first wall, duplicate it while it is still selected and press the button to rotate the duplicated piece of wall, then move it to its correct position. The rule from above applies here as well, the walls should just touch each others edges, they should neither touch each other with a whole side, nor overlap each other.

So, are all the walls at their correct place and they all look alright in the 3D view? If that is the case, let's carry on, if not, read through the lines above once more and try again. So now that all walls are in their correct place, we just need to texture them. So first, deselect everything so that you don't make any weird mistakes (ESC), then select each of the walls (SHIFT+CLICK) and click the button to apply the caulk shader to all the walls. This is because you only want the visible parts to have a texture, this isn't so very important in small maps like this, but when the maps you make grow in size and complexion, this is important to save performances, so, it's better you get into the habit of doing it, so every side (I will call the sides faces in the future) should be textured with that shader for now.

After all the walls are nice and pink, it's time to apply a visible texture to those faces (remember that means sides) you will see when you play your map, in this case, that would be the faces of the walls only. To put a texture on them, select a texture folder in the folder list, then click a texture and a red rectangle should appear around it, this means that the texture is selected. To apply the selected texture to the surface of the walls, simply hold CTRL+SHIFT and click your mouse wheel on the inner faces of the walls. This should be done in the 3D view.

If you have done everything correctly, you should now see a room with walls and a floor, the only things left now are the ceiling, a spawn point and a light, but those will be covered in the next chapter.

title: GtkRadiant/The Walls


text:
Subject:Medicine

医学

title: Subject:Medicine


text:
User talk:67.142.130.24

 – Mike.lifeguard  | talk 20:30, 7 September 2007 (UTC)

title: User talk:67.142.130.24