Why does the voltage increase when capacitor plates are separated?

Question: In lab, my TA charged a large circular parallel plate capacitor to some voltage. She then disconnected the power supply and used a electrometer to read the voltage (about 10V).  She then pulled the plates apart and to my surprise, I saw that the voltage increased with distance. Her explanation was that the work she did increased the potential energy that consequently, increases the voltage between the plates but the electric field remains constant. Although I tried to get more of a physical explanation out of her, she was unable to give me one. Can someone help me here?
Comment: I saw this demo also and was complete lost on the explanation. Great question.
Answer: Toby, I agree that this is really counter intuitive and I was also quite surprised as well when I first saw this very demonstration. I am an undergraduate TA and this is how I explained it in my lab section. I hope this helps. I see two parts to a full explanation: (1) Why is the electric field constant and (2) why does the potential difference (or voltage) increase?
Why is the electric field constant as the plates are separated?
The reason why the electric field is a constant is the same reason why an infinite charged plate's field is a constant. Imagine yourself as a point charge looking at the positively charge plate. Your field-of-view will enclose a fixed density of field lines. As you move away from the circular plate, your field-of-view increases in size and simultaneously there is also an increase in the number of field lines such that the density of field lines remains constant. That is, the electric field remains constant. However, as you continue moving away your field-of-view will larger than the finite size of the circular plates. That is, the density of field lines decreases and therefore, the electric field decreases as well as the potential field.

To show this mathematically, the easiest way to show this for E = constant is using the relation between the electric and potential fields:
 $$E = -\frac{\Delta V}{\Delta d} \longrightarrow \Delta V =-E \Delta d$$
I would expect the voltage to increase linearly as long as the field is constant. When the electric field starts decreasing, the voltage also decreases and the fields behave as finite charged plates. Although I've only talked about one plate, this idea immediately applies to two plates as well.
Why does the work increase the electrical potential energy of the plates?
One way to interpret why the voltage increases is to view the electric potential (not the electrical potential energy) in a completely different manner. I think of the potential function as representing the "landscape" that the source (of the field) sets up. Let me explain what the gravitational potential acts like when a ball is thrown upwards (of course, you know what happens in terms of the force of gravity or in the conservation of energy scenario). I claim that the potential function is related to the "gravitational landscape" that the earth sets up, which is derived from the potential energy and is equal to the potential energy per mass:
$$ {\Delta U = mg\Delta y}  \longrightarrow \frac{\Delta U}{m} =  \Delta V = g\Delta y$$
Plotting these functions, the constant gravity field sets up a gravitational potential ramp (linear behavior) that looks like

In terms of energy, the ball moves up this gravitational ramp were the ball is converting its kinetic energy into potential energy until the ball reaches it maximum height. However, the gravitational ramp exists whether the ball is thrown up or not. That is, gravity sets up a gravitational ramp (the landscape) and this is what the ball "sees" before it is thrown up.
If we now apply the above thinking to a constant electric field between the parallel plates, the electric potential function is derived in a similar manner:
$$ {\Delta U = qE\Delta r}  \longrightarrow \frac{\Delta U}{q} =  \Delta V = E\Delta r$$
If we look at the electric potential of the negative plate (it's easier than the positive plate), it has a negative electrical ramp that starts at 0V.

So as your TA pulls the plates apart, the work she does moves the positive plate up the electrical ramp and increases the potential of the positive plate. So this interpretation of the electric potential is what you intuitively already think about in terms of mechanical situations like riding your bike up a hill. There is no difference in the electrical situation.
Comment: @Carlos - Your way of explaining why field E is constant and then it reduces is beautiful; thanks a lot. But your answer that potential would decrease as a result of decrease in electric field is incomplete, as potential is dependent on distance too and it is increasing. I think the appropriate way would be - "electric field reduces after a certain point; potential would reduce only after a point where the rate of decrease in electric field is larger than the rate of change of distance"...Correct me if I am wrong...
Comment: Thanks for taking the time to write such a long and detailed answer. Love your images. What software do you use to create these?
Comment: @Toby, I don't know if this is what Carlos used for this particular answer, but they look like they could have been done in [Inkscape](http://inkscape.org/).
Comment: @Toby: Your welcome and I used Snagit by TechSmith to create those images.
Answer: Here is my understanding:
When you increase the distance between electrodes - capacitance drops, but stored charge remains the same, as electrons have nowhere to go.
Same charge in lower capacitance means higher voltage potential. Without that part of stored energy would just vanish :-)
Comment: I agree.    Q = C.V     The capacitance is inversely proportional to the plate spacing, so long as it is small compared to plate length and width (fringing fields), doubling the space, halves the capacitance, and doubles the Voltage, so long as the charge is unchanged.
Answer: I think as we know E = V/d, and the field is same, so for field remains constant between the plates of the capacitor, while increasing the distance the potential also increases. In the same manner as that of distance so that the ratio of V and D is same always.
Answer: It is easy!
We know that
C=q/U, where
C - capacitance,
q - electrical charge,
U - voltage between plates,
Charge (q) can not change, but when plates are separated, capacitance goes down so U goes up!
Answer: When the two capacitors are charged, they are constantly trying to come closer due to electrostatic forcd between them, when you displace the plates away from each other there is a net displacement in opposite direction to that of force, hence - work is done by the capacitor system or in other words the energy of this system increases which gets stored as electrostatic potential.
Another explanation can be that a certain capacitor system is able to hold charges at lesser potentials than a single conductor can. This implies that for capacitors of lower capacitances you need more potential to store the same amount of charge, what your TA did was reduce the capacitance of the system so now to hold the same amount of charge the potential increases. You can also see that for large plates using approximations electric field comes out to be independent of distance, so when your TA pulls the plates apart thr electric field does not change; However potential depends directly on both electric field and distance. Sos even when electric field remains constant, the increment in length between the plates increases the potential difference.
Answer: as you know that inside a capacitor electric field remains same. If you increase the distance between the two plates electric field does not change just because electric field= surface charge density/ epsilon. so E=V/D gives increment in V as D increses so that electric field remain same.
Answer: The explanation is simple.
Start with a definition of voltage: the work done moving 1 coulomb of charge from point $a$ to point $b$. In this case $a$ to $b$ is one plate of the capacitor to the other, since we are talking about the voltage across the capacitor.
And now a definition of the work done: it's $\text{force} \times \text{distance}$.
A capacitor has an even electric field between the plates of strength $E$ (units: force per coulomb). So the voltage is going to be $E \times \text{distance between the plates}$. Therefore increasing the distance increases the voltage.
Answer: I see it from a vector addition perspective. Using a single test charge in the directly between the plates, the force vectors created by individual charges on the plate begin to point more "horizontal" as the plate is moved away from the test charge. So although the individual vectors decrease in length, the horizontal components of forces from charges at the edge of the plates increase maintaining a constant overall field strength. I'm sure there is a mathematical proof, but this is how I'll explain it to my HS physics students. Does this make sense?
Answer: Opposite charges attract. Pulling them apart requires external energy supply that would be stored in charge system. As charge remains constant, per charge energy increases as well (that is potential difference).
Answer: I think I may have a good explanation for you.  I've been an electrical engineer for nearly 3 decades and I teach circuit theory as well.  I need to explain how a capacitor works all the time.  Let's start with a metaphor:

You pick up a rock and put it atop building 30 feet tall.  It now has potential energy stored relative the ground, stored in the gravitational field (which we assume is constant at these elevations).  That energy came from a crane that put it up on the top.  We could get that energy back by dropping the rock and converting it back to kinetic energy at the bottom.  Think about this - initially, the ball had ZERO kinetic energy (when sitting on the ground) but now it has kinetic energy when it comes back to the ground.  Why?  An external force gave it to the rock (the crane) in the form of potential energy and we retrieve it in the form of kinetic (which ultimately gets lost as heat as the rock comes to rest).
Now, take that rock sitting atop the 30 foot building.  It's the same rock as before. And instead of pushing it off the roof, the crane picks it up and lifts it another roof another 30ft above, so now the rock is 60 feet above the ground.  Now push it off the higher roof - when it hits the ground, it is moving even FASTER than before - it has DOUBLE the kinetic energy it had when it was pushed off the 30 foot building!  How did that happen? How does it now have DOUBLE the potential energy? Well, by using the crane you stored DOUBLE the potential energy in the gravitation field.
How do we know we "stored it in the gravitational field?"  Because if the gravitational field were to suddenly vanish, the rock would just sit there, even pushed off the roof, and not drop.  Now where is the energy? Is it gone?  Well, yes, if the gravitational field simply "went away" we wouldn't have needed it the first place.

So what does this all mean?  Well, the exact same logic applies to capacitors.
1) Instead of a rock, let's say the rock is an electron.
2) Instead of a crane, let's say the crane is a battery that can move electrons.
3) Instead of a graviational field, let's say it's an electric field.
So....
We take a pair of metal plates and form a parallel plate capacitor.  And we make sure the distance between the plates is REALLY REALLY THIN relative to the area of the plates.  This means that any electric field between the plates will be constant - just like the gravity is constant close to the earth (it is, really, trust me!).
Next, we take the battery, which can rip electrons off of one plate and "stick" them onto the other.  How?  Chemistry - but that's not important right now.  Let's just know that it took ENERGY of some kind and we added it to the electron, and now it is on the other plate.
What just happened?  The pulled electron leaves an unmatched proton on the lower plate.  So there is now an ELECTRIC FIELD established between the plates.  We have STORED the energy from the battery in the electric field. How do I know this?  Because if the field could magically "vanish" the electron would just float around happily on the other plate and not be pulled by the proton (again, this was if the electric field could suddenly vanish - which it can't - just like gravitational field just can't "vanish").
Since voltage is the amount of energy that gets stored per unit charge (Joules/coulomb is how Voltage is measured - it's a derived quantity!).  We must be able to get that energy back. How?  KINETICALLY!!!
Suppose you disconnect the battery, and the plates are 1mm separated.  And let's then assume you have really really really tiny tweezers and you could yank the electron off the upper plate, put it next to the plate, and let it go.  What would happen?  It would go whizzing back to the proton from where it came from in the first place and essentially "crash" into it with kintetic energy.
So think about it.  I take an electron off of the lower plate. It initially had no kinetic energy.  A battery "sticks it on" the upper plate by using its chemical energy - giving the electron "potential energy" which gets stored in the ELECTRIC FIELD between the plates.
NEXT:  Let's suppose instead of a battery, i use my hands and now separate the plates from 1mm to 2mm.  That electron that we put on the top plate, is now still on the top plate, but guess what, our HANDS ADDED ENERGY to pull the plates apart a little bit, so little, we didn't even realize we did it - but we did!  We added just a LITTLE BIT more potential energy to the system.
This extra energy is now stored in the electric field.  How do I know?  Because again, if this electric field suddenly vanished - the electron would just sit there, not getting pulled towards its matching proton.
Now, let's suppose I pluck off that lone electron and drop it next to the plate.  It will now whiz back to the proton, but since the distance was double, it would have TWICE the kinetic energy it did before.  It crashes onto the bottom plate, and loses this kinetic energy to HEAT.
The mechanical and electrical systems described herein are metaphorically identical.
The key learning here is that we store mechanical energy in a GRAVITATIONAL field.
WE store electrical energy in an ELECTRIC field.
The real question is not "why did the voltage go up" but rather, "why does a gravitation field or electrical field allow us to store energy within it."
And that is where the real mystery continues to lie.  We still don't know.  We don't know how a positive charge "pulls" on a negative charge, just like we don't know how two masses pull on each other.
All of what is written above holds true so long as you assume the gravitational field or the electric field remain CONSTANT while raising the rock or pulling the plates apart.  And this is a very real behavior so long as the scales are small.
Gravity is essentially constant for hundreds of miles above the surface of the earth until the field weakens farther out in space.  The principles still apply, but now you have to use calculus to figure things out.
Electric fields between two parallel plates are essentially constant when the plates are very close together.  Once the distance between the place gets large, relative to the surface area of the plates, then again, the principles still apply, but you can't assume the field is constant.
Oh, and one final thought about this:  We generally use a resistor as the path for the electrons to return to the lower plate.  And what gets created as this occurs - HEAT is generated.  Why?  Because as the electron attempts to return to the bottom plate at near the speed of light, it gets slowed way down by the resistor which gets heated up in doing so, absorbing the kinetic energy along the way.  That way, when the electron gets back to the bottom plate, guess what, it has no more kinetic energy, just the way it started when the battery pulled it to the top plate in the first place.
Hope this helps!
Comment: You go a little overboard on the ALL CAPS. Maybe tone it back a bit?
Comment: It's not a negative tone, just a bit of an eyesore. Welcome to the site, by the way :)
Comment: Chris, thank you - I removed the over-the-top caps.  I was trying to emphasize not offer negative tone.  I appreciate the feedback.  I love this stuff, and I'm passionate about it.
Answer: Carlos' answer is fine, but here is a direct and physical way to think about why the voltage increases when the separation between the plates increases. The answer in this video is helpful in my opinion since it doesn't require any discussion of electric field to answer a question that is fundamentally about electric potential.
https://youtu.be/NC_j9GQEwU0
Answer: Capacitance increases as the voltage applied is increased because they have a direct relation with each other according to the formula $C=Q/V$. Capacitance decreases as the distance between the plates is increased because capacitance is inversely proportional to distance between the plates according to a relationship $C \propto \frac{1}{d}$.
Comment: The capacitance is (approximately) constant with respect to the voltage. That is the whole point of the capacitance: It describes how much charge is stored on a capacitor in dependence of the voltage (in other words: the charge increases when the voltage increases).


Extract text out of two lines in a file and output them in a table

Question: I am trying to make a PHP script for my school. School's web directory has about 100 text files, one text file for each student. Every text file has a two lines like:
stu $id = '12701';
stu $name = 'alex';

I want to echo out this id and name value in a table. But those two line are random. It might be at line number 23 and 24, or sometimes 45 and 46.
Here's my attempt:
$directory = 'lessons/'; // The directory to the lesson text files

$linesToReturn = 50; //  i tired to read top 50 lines , so i can grab from them.

// Find all files in the directory which are .txt files
foreach( glob( $directory . "*.txt" ) as $filename )
{
    // Open the file
    if( $handle = @fopen( $filename, "r") )
    {
        $x = 0; // Start the line counter

        // Cycle each line until end or reach the lines to return limit
        while(! feof( $handle ) or $x < $linesToReturn )
        {
            $line = fgets($handle); // Read the line

            $lessons[$filename][] = $line;

            $x++; // Increase the counter
        }

    }
}

// creates a blank list if no files or valid files were found.
if(! isset( $lessons ) ) $lessons = array();

// The rest of the page just builds a simple table to display each lesson.-
echo '
id & names
';
echo '
';
echo 'id	name	';

foreach( $lessons as $file => $details )
{
    echo '
' . $details[0] . '	' . $details[1] . '
 ';
}

echo '
';

But this doesn't work. What am I doing wrong?
Answer: Perhaps you could use a regular expression to grep out the id and name, something along the line of:
id=nil
id = line.match( /stu\s+\$id\s*=\s*\'(\d+)\';/)[1] unless id
You might also want to store the data in a more convenient data structure e.g.:
students[ id] = name
Comment: can you write the full ocde for me ? @Niels Tolstrup


Why would oil be leaking from radiator?

Question: Car is 98' Chrysler Concorde and oil has started flooding out of the radiator. Found a crack in the oil cooler hose and changed that but it still Will not hold the oil
Answer: Embedded in your cooling system radiator is a transmission oil cooler, it comes as part of the radiator. From your description, "... oil flooding out..." it would appear that your oil cooler has burst/split, and is pumping transmission oil out onto the floor. If this is so it  will mean a replacement radiator/oil cooler assembly.
Comment: Also a complete and thorough transmission flush - if transmission fluid's getting out while the car's running (fluid is pressurized), coolant's getting IN while the car's NOT running (fluid NOT pressurized, but hot cooling system pressurized).

Why would oil be leaking from radiator?


How would pornstars recover if they converted?

Question: Lets say porn stars or a prostitute or whatever else there are wanted to convert to Islam. How could they recover from sin if their images of nudity are permanently on the internet for everyone to view, people can see their nude body and this is a sin so even after converting to Islam despite having sins wiped away wont it still be a sin as they are still sheoung their nude body online?
Comment: Your question is based on a wrong assumption. Islam washes away all earlier sins. I'd assume we have relevant posts and answers on the site.
Answer: Any sins they earn after conversion would still be counted as sins. Presumably after conversion they would stop showing their nude body publicly, and if not they should be informed that such behaviour goes against Islamic teachings.
What people do with the nude images that were generated before, insofar as they are completely out of the converts control, is irrelevant.
Comment: So if even if the persons nudes were still onlone if they stopped with their actions it is all ok. But doesnt the nudity lead men/women to commit other sins.
Comment: @NazreenShahid So what? How is it the convert's responsibility to stop other people from committing sins when they have zero control over them?
Answer: Allah says regarding repentance, ((Except those who repent and amend and make manifest (the truth). These it is toward whom I relent. I am the Relenting, the Merciful.))
So three act!
1. Repentance from the sin
2. Amendment of the falsehood
3. Manifestation of the truth
One should use all the means possible to delete these pictures! It takes a lon time, but a person have to be persistent. This is a human right! If one live in a country where human right is practice, they should use the law to let their picture taken away! If the person is very rich, they should even strive to make agreements and pay people money to delete their picture forever.
I know an Egyption singer who repented and made a deal with the music industry that she would sing islamic songs for them to record and sell, if they agree to delete all videos and song she made in the past! And after 20 years, you couldn't find any of her old songs!
It's not enough just to repent! One should strive to do good deeds that would amend the wrong deeds that was done before! A person has to promote the opposite! In this case the person need to preach against the wrong things they use to do to oppose the wrong message they were preaching before and so preach the right message! This is a justice social balance one is dutiful toward!
Allah knows best


Time series trend

Question: I have a time series which has a very strong upward trend for the first half, then very strong downward for the second half and finishes pretty much back where it started.
Should I split the data in two for analysis - or can I still account for a trend which is net neutral?
Comment: There should (or at least could) be some substantive knowledge explaining this strong qualitative behaviour. Similarly, separate analyses for separate parts of a series imply quite different generating processes; that could make sense if you had knowledge that the system became fundamentally different at the turning point. Absent this, it is difficult if not impossible to give a worthwhile technical reply to your question without much more information.
Comment: You mention *analysis* but it's not clear what you actually want to do.
Answer: I think you can actually fit one model that can capture both upward and downward trends and there is no need to split your data (unnecessary) resulting in two models. In the following codes I have consiered an ARIMA model (red line) as well as plynomial regression of degree 2 (blue line). I fitted these model just as an example. Sometimes you actually need to split your data (See Nick's comment).
<code>> x=0:40
> y=-(x-20)^2+rnorm(length(x),0,15)
> plot(x,y)
> library(forecast)
> f=auto.arima(y)
> summary(f)
Series: y
ARIMA(0,2,2)

Coefficients:
          ma1     ma2
      -1.4522  0.7282
s.e.   0.1240  0.1156

sigma^2 estimated as 451.2:  log likelihood=-175.89
AIC=357.78   AICc=358.46   BIC=362.77

Training set error measures:
                    ME     RMSE      MAE      MPE     MAPE      MASE
Training set -6.162264 20.71692 16.32124 30.21502 52.33051 0.1559912
> lines(fitted(f),col="red")
> f2=lm(y~x+I(x^2))
> summary(f2)

Call:
lm(formula = y ~ x + I(x^2))

Residuals:
    Min      1Q  Median      3Q     Max
-40.465  -8.068   2.406   9.482  23.517

Coefficients:
              Estimate Std. Error t value Pr(>|t|)
(Intercept) -401.88742    6.64150  -60.51   <2e-16 ***
x             39.38738    0.76813   51.28   <2e-16 ***
I(x^2)        -0.97488    0.01857  -52.51   <2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 14.87 on 38 degrees of freedom
Multiple R-squared:  0.9864,    Adjusted R-squared:  0.9857
F-statistic:  1381 on 2 and 38 DF,  p-value: < 2.2e-16

> lines(fitted(f2),col="blue")
>
</code>
Answer: Such time series are usually hard to model using ARIMA. But I suggest you plot the ACf and PACF of the series and see. It may require differencing. You can also test to see if the variance is constant; if it is not you transform. Once the data is stationary you can make sense out of it.
As Nick has said splitting the series will generate two different processes and more information is needed.
The series might appear to be oscillating: if that's the case the best thing to do is to try spectral analysis.
Comment: Thanks for the mention, but you have my point backwards: if the processes generating the series are different, then separate models might make sense; it's processes that generate data, not vice versa, as I use terms. Also, the implication that you need to make series stationary to make sense of them does not seems to me to reflect best current thinking on time series.
Comment: Thanks for the correction. Making the series stationary before analyzing might no be the best way, but it makes it easier to analyze that way.
Answer: I have had significant success in empirically identifying trend changes using AUTOBOX http://www.autobox.com/cms ,a commercially available piece of software that I have helped develop. You might want to look at stochastic vs deterministic trend/seasonality in time series forecasting for an interesting discussion.
A time trend model (deterministic in form) is as follows  y(t)=a+bx1+cx2
etc where x1=1,2,3,4....t and x2=0,0,0,0,0,1,2,3,4 thus one trend applies to observations 1−t and a second trend applies to observations 6 to t.
AUTOBOX's automatic empirical procedures have been very successful BUT like all "new science" or "advanced innovative procedures" it needs to be constantly aggressively challenged. Test all things but hold fast to what you know to be true ! Please post your data or send it to me privately and I will use the data and report the results to the group. If you are skittish about releasing the data simply code it by adding/subtracting a constant. The procedures used to identify the number of trends and the length of each trend is based partially on the work of Tsay http://www.unc.edu/~jbhill/tsay.pdf. All of these advanced procedures are not currently available in the free software market.

Time series trend


How to serve Craft with Caddy server

Question: Caddy seems to be an easy to use alternative to established web servers. How does the Caddyfile look like for a Craft site?
Answer: For local development the Caddyfile looks like this (assuming that php-fpm runs on port 9000, you may have to adapt root to point to your web root relative to the location of the Caddyfile):
localhost:2020 {
    root public_html
    fastcgi / 127.0.0.1:9000 php
    rewrite {
        r .*
        to {uri} {uri}/ /index.php?p={uri}&{query} /index.php?{query}
    }
}

Edit: For Caddy >= 0.9.x the rewrite has to be changed to this:
rewrite {
  to {path} {path}/ /index.php?p={path}&{query} /index.php?{query}
}

Comment: Have you noticed any issues with running tasks with Caddy server? I've noticed that even P&T's own PowerNap task example doesn't run properly on Caddy.

How to serve Craft with Caddy server


Arduino due erase button and power switching

Question: Last days I have been investigatin schematics of arduino due board. The purpose of proper understanding of schematics in crucial for me, beacuse I indend to build myself my own board with some minor modifications.
I would really want to learn something from it and not just blindly copy stuff that are already done. In schematics there are two things that I do not understand. First is the working principle of erase button (see: erase button). I have my own idea how does it work, but would like to clarify the working principle from someone that know exactly what is the purpose of all the elements that are connected to erase button. Also, why is ERASE_CMD  line connected to Atmega processor?
 Second thing is switching of power supply between external power and both usbs (see: usb switch). Again, would someone please just brifly describe working principle? Here I really do not undertand why is there op amp added?
Thank you in advance.
Erase button:

USB switch:

PLEASE NOTE: Both pictures are taken from original arduino webpage: https://store.arduino.cc/due  (see: documentation -> schematics)
Answer: The asker posted the same question and received an answer here
There is discussion regarding the purpose of the Erase switch here
Comment: You're encouraged to summarize the essentials such that the answer will remain useful if the links become broken.


What is the meaning behind the ant logo of "The Prodigy"?

Question: The Prodigy are an English electronic music band formed in the 1990's. The band has used several logos through the decades. In particular, from the mid-1990s to 2000 their logo featured an image of an ant. Does anyone know about the real meaning behind their ant logo?
Comment: The name of the group comes from the keyboard Liam Howlett used to create many of the early releases.
Answer: I asked my friend Paul, currently sunning himself in Spain, and listening to the Prodigy back catalogue, and he found this Instagram post  from which this quote :

Last wednesday, November 21, Liam Howlett gave the special interview
  for theprodigy.ru, where he noticed: «The ant is used because they are
  small and powerfull, that's how we think of ourselves — you might not
  hear from us for a bit and then BLAMMM! But if you look closely, we
  are always there».

I can't locate the Nov 21 2018 interview, but sounds like this is it.


Adiabatic equation of an ideal gas

Question: Why in the adiabatic equation of an ideal gas do we take
$dU= C(v)dT$ , where $C(v)$ is the specific heat capacity at constant volume ? I mean that in an adiabatic expansion or compression the Volume doesn't stay constant so why do we take $C(v)$ ?
Comment: Welcome on Physics SE :) If you want to make your question look a bit nicer, there is a [formatting help page](http://physics.stackexchange.com/help/notation) :)
Answer: Based on Adiabatic Equation Wikipedia

Derivation of $P–V$ relation for adiabatic heating and cooling
The definition of an adiabatic process is that heat transfer to the system is zero, $δQ = 0$. Then, according to the first law of thermodynamics,

$${\displaystyle {\text{(1)}}\qquad dU+\delta W=\delta Q=0,}$$

where $dU$ is the change in the internal energy of the system and δW is work done by the system. Any work (δW) done must be done at the expense of internal energy $U$, since no heat $δQ$ is being supplied from the surroundings. Pressure–volume work $δW$ done by the system is defined as

$${\displaystyle {\text{(2)}}\qquad \delta W=P\,dV.}$$

However, P does not remain constant during an adiabatic process but instead changes along with $V$.
It is desired to know how the values of $dP$ and $dV$ relate to each other as the adiabatic process proceeds. For an ideal gas the internal energy is given by

$${\displaystyle {\text{(3)}}\qquad U=\alpha nRT,}$$

where $α$ is the number of degrees of freedom divided by two, $R$ is the universal gas constant and $n$ is the number of moles in the system (a constant).

Differentiating Equation (3) and use of the ideal gas law, $PV = nRT$, yields
$${\displaystyle {\text{(4)}}\qquad dU=\alpha nR\,dT=\alpha \,d(PV)=\alpha (P\,dV+V\,dP).}$$

Equation (4) is often expressed as $dU = nC_V dT$ because $ C_V = αR$.
Comment: But why can dU be takes as nC(v)dT when volume is not constant in the expansion
Comment: And why can't we take dU=nC(p)dT where C(p) is the specific heat at constant pressure
Answer: The subscript v on Cv refers to how Cv can be measured for a given material experimentally, namely, by specifically measuring the amount of heat Q added in a constant volume test.  It does not mean that Cv canand not be used determine the effect of temperature on internal energy U for other situations.  In fact, for an ideal gas, U is a function only of T, irrespective of v. So, in that case, dU=nCvdT can be used to determine the change in internal energy in all situations.
Comment: If you're solving a problem in terms of internal energy, you use Cv.  If you're solving a problem in terms of enthalpy, you use Cp.  Actually, U is the fundamental quantity, and H is just a convenient parameter that arises mathematically in many problems.  But, all problems that can be solved in terms of H can be solved in terms of U.  Don't forget that, for an ideal gas, H=U+PV, so H=U+nRT, and Cp=Cv+R.
Comment: So why can't we use dU = nC(p)dT where C(p) is the specific heat capacity at constant pressure
Comment: $C_p$ is defined as $$nC_p=\left(\frac{\partial H}{\partial T}\right)_p$$
Comment: $C_v$ is defined as $$nC_v=\left(\frac{\partial U}{\partial T}\right)_v$$
Comment: @ChesterMiller  But what is the point of using C(v) ....why not just use C(p) since you have said that  C(v) can be used and it doesn't matter if the volume is constant or not. Same should be applied to C(p). It won't matter is the pressure is constant or not. Why can't we use C(p) and just use C(v)
Answer: $U$ is a state function, which means that $\Delta U$ depends solely on initial and final states, and not on which process it went through in between. For ideal gas $U$ depends on $T$ alone. Hence once you know initial and final temperature, $\Delta U$ is thereby completely determined, irrespective of which process it went through in between.
Answer: For an ideal gas
ΔU=$C_{V}$ΔT
is always true regardless of the process.
Proof:
Consider any reversible process that takes the ideal gas(n=1) from an initial(P1,V1,T1) to final state(P2,V2,T2).

Since the process is reversible we can consider infinitesimal differential changes from (P,V,T) to (P+dP,V+dV,T+dT'') as the system goes from initial to final state.
At each of these steps, since U is a state var,calculate dU from an attached isobar and isochor betweeen same endpoints.

isobar from (P,V,T) to (P,V+dV,T+dT'):
  dQ=$C_{P}$dT' where dT'=PdV/R (from PV=RT-this is why its valid only for ideal gas)
  dW=PdV
isochor from (P,V+dV,T+dT') to (P+dP,V+dV,T+dT'+dT'')
  dQ=$C_{V}$dT'' where dT''=VdP/R (from PV=RT)
  dW=$0$
total dU=$C_{P}$PdV/R -PdV    +    $C_{V}$VdP/R-$0$
  then using $C_{P}$-$C_{V}$=R (this derivation also requires PV=RT)
  dU simplifies to $C_{V}$dT

Since the process is reversible, we can integrate the differential to get
ΔU=$C_{V}$ΔT (assuming $C_{V}$ to independent of T-true for an ideal gas)

please see.

Adiabatic equation of an ideal gas


Why is 51.8° inclination standard for Soyuz?

Question: Soyuz flights are mostly around 51.8° inclination, and the Soyuz manual gives this as a reference value. Why is 51.8° the standard inclination? That's not the latitude of Baikonur, and I couldn't find any explanation on Google.
Comment: https://space.stackexchange.com/questions/5297/why-doesnt-iss-pass-over-the-polar-regions/5298#5298
Answer: As Baikonur is at 45.965° north latitude, it would make sense if 45.965° was the standard inclination for Soyuz (and for the ISS). That would be a launch due east, thereby taking the greatest advantage of the Earth's rotation. The reason the standard inclination is 51.8° is that a failed due east launch might rain debris on China. Avoiding passing over China during launch while still taking as much advantage of the Earth's rotation as possible requires launching a bit north of due east and results in an inclination of at least 51.65° (the inclination of the ISS).
Comment: This explains most "weird" trajectories. Why does Israel launch retrograde? Why does the Polar Corridor from the Cape involve a dogleg? And so on. The answer is always to avoid overflying inhabited territory, either enemy (Israel), friendly/neutral (Cape) or your own (Vandenberg).
Comment: @JörgWMittag Israel is a particularly interesting case. They launch due west to avoid raining down debris on their own territory or on potential enemy territory, thereby incurring a 30% penalty on mass to orbit compared to launching due east. Many Israeli satellites have been launched by other countries' launch vehicles. However, national pride dictates that Israel must have its own launch capability despite that 30% penalty.
Comment: @JörgWMittag [The strange orbit of Ofeq 11 - how does it (actually) do this?](https://space.stackexchange.com/q/18295/12102) and [Why use a retrograde orbit?](https://space.stackexchange.com/q/36163/12102)
Comment: @DavidHammen: They also launch military satellites. I'm not sure they could have hired that out until very recently.
Comment: @DavidHammen  National pride AND ensuring that they have the capability when needs must. Israel cannot afford to be wholly beholden to any other country for 'mission critical' functions. You know that :-)


Locked out with no service!

Question: I was fiddling with the lock your SIM card features and locked it, but the password I used now will not open it, and it is locked with no service, screen says screen is PUK locked and is asking for  an 8 digit password to change the PIN code, which the one I typed when trying to set it was only 4 digits. I think I must have clicked change password right before it locked me out. What do I do now?
Answer: Some SIM cards have PUK codes printed on the punch out cards that the SIM card came from.
T-Mobile for example has PUK code printed on the plastic punch out.
Comment: That's correct. All SIM cards I've seen come with PIN1, PIN2 (both 4-digit), PUK1, and PUK2 (both 8 digit). If you locked the PINs, you can use the PUKs to unlock. If you locked the PUKs, too – well, then you need a new SIM.
Comment: If I locked the PUKs by accident, then if i was changing the PIN for the SIM card, wouldn't the PIN be the same? I literally just did it, so I know what I typed. I am wondering if I am typing the right PUK though. Which number on the SIM is the one it wants? I'm running out of tries! Should I just take it to Verizon? Can they reset it?
Comment: Yes, they would either unlock it or simply replace your sim for you.

Locked out with no service!


Deceived by car salesman

Question: I thought I was a co signer for my daughter to help build her credit but she is not on the loan  I founded out a year later She is upset, faithfully pays the note and gets  no credit for it.  I did not have a job how could that happen  and what can I do because the salesman trick us and told me after a year she could have my name taken off but now she is not on the car what could we do about this deception
Comment: Whereabouts in the world are you located? This may be more of a legal question and the treatment of such things depends on where you live.
Answer: The only thing that is important here is the documentation you and your daughter signed. If that documentation states that you were a co-signer and that your daughter was the primary on the loan, and then if the loan is not being reported in your daughter's name, you have a cause for action. If, however, the documentation says the loan is entirely in your name, the mistake is yours. Even in that case, though, your daughter may be able to take over the loan, or she may be able to take out a loan from a separate institution and use that to pay off the current loan. Obviously, this may be difficult if she does not have a credit history, which is what got you here in the first place. :(
Comment: Yes my mistake for believing lies they told us. She is not on the loan at all but is paying for the loan thinking her name is on the loan with mine I don't know how they gave me a loan  with no job. I would never gotten that car if I had a job something my daughter was trying to purchase and I  failed her and myself by not knowing what was happening. Now she have 5 years to pay for a car she's not getting credit for if the dealership don't come up with something to make good on a bad deal.
Comment: @ElainePatton - did you confirm by looking at the actual documents you signed? If you can't find it, both the dealership and the bank who currently owns the loan should be able to give you a copy. As ChrisInEdmonton suggested, look at the document and see what it says.
Answer: At this point there is not much you can do.  The documentation probably points to you being the sole owner and signer on the loan.  Then, any civil suit will degenerate into a "he said, she said" scenario.  Luckily, no one was truly harmed in the scenario.
Obtaining financing through a car dealer is almost always not advisable.  So from here, you can do what should have been done in the first place.  Go to banks and credit unions so your daughter can refinance the car.  You will probably get a lower rate, and there is seldom a fee.
I would start with the bank/CU where she does her checking or has some other kind of a relationship.  If that fails, anywhere you can actually sit and talk with a loan officer is preferable over the big corporate type banks.
Car dealers lying is nothing new, it happens to everyone.  Buying a car is like a battle.

Deceived by car salesman


How Do Addresses Function?

Question: I understand that an address is needed to send Bitcoins to other people, but I do not understand why you are recommended to generate a new address for each transaction. Also, I have read that an address can be saved for easy payment in the future, but I don't understand how this function would be possible if new addresses are generated every payment. Thanks so much for your time and help! It is much appreciated.
Comment: I think you may be misunderstanding how addresses work in Bitcoin. https://en.bitcoin.it/wiki/Address
Answer: The simple answer is you have a keypair for each bitcoin address, public key & private key, you can think of this as a username (public key) and password (private key). You can share your username/public key with as many people as you'd like, whether you know/trust them or not, of course you must keep your private key to yourself. The interesting part is that the public key is derived from the private key, and you sign messages with your private key to prove that you know it without giving away what the private key actually is (this is verified by comparing your public key with the message you signed).
The technical way that you create a private key can be found at the offical bitcoin wiki here: https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses
This wiki has a LOT of information, and is the most accurate source on bitcoin related information I have found to date.
Answer: What they're saying is that you can use an address repeatedly, but you shouldn't because it hurts your privacy, and it hurts the privacy of anyone who sends a coins to a reused address.
New addresses are generated every payment as Change Addresses. As you may know, partial coins cannot be sent, just like you can't tear a banknote in half and give someone half of it. So every time you send someone money, unless it is a whole coin, your client will generate a new change address to receive change for. That is for sending money.
However, if you want to receive coins, you can just have a QR code that displays a single address that everyone can send to.
When I say "whole coins" and "partial coins", I don't mean ฿1, instead I mean the individual transactions' inputs and outputs. I could get into that if you ask.
Comment: Thanks for the response! I understand that your client generates a change address, but why would they recommend to save an address for future reference? Wouldn't this make it inconvenient for regular customers to make a transaction to the same business.

How Do Addresses Function?


Nearest Neighbor distance frequency distribution

Question: I have a dataset of 6455 points. Is there a way to produce the frequency distribution of nearest neighbour distances in the data set in ArcGIS 10.3?
The Average Nearest Neighbor tool only produces the mean distance, not the whole distribution.
Answer: You can use Generate Near Table to obtain the nearest neighbour distances and then use a pivot table in excel to create the frequecy distribution. That should work.
Comment: Glad it did! Could you please mark my answer as the best answer. That is the best way express thanks here! Have a good day.
Comment: Thanks! That worked. If the 'Generate Near Table tool' would have been visible in the toolbox when using the basic level license (as I usually do), perhaps I could have figured it out myself...


Odds ratio for continuous dependent variable by regression analysis

Question: Can the odds ratio be calculated for a continuous dependent variable using logistic regression? If yes, kindly explain the procedure in SPSS. Further, can we apply logistic regression to an dependent variable when it is a scale without dichotomizing it? Since I need to report the odds ratio after adjusting for multiple variables to an outcome that is continuous, I have dichotomized it and have applied logistic regression, but I want to do the same for it in its continuous form (I need to report the odds ratio for both the models, i.e., continuous and dichotomous). If this is possible kindly explain.
Answer: I don't use SPSS but yes you can use a proportional odds ordinal logistic model on continuous $Y$.  Don't use any grouping/dichotomization of $Y$.  The R rms package orm function handles this efficiently for up to 6000 distinct $Y$-values (i.e., up to 5999 intercepts in the model).  A case study appears here.


Why does changing the 3D cursor move other quad view windows?

Question: Just discovered the quad view option (CTRLALTQ) and love it. However, I have a problem that I have not been able to find a solution to. When I change the position of the 3D cursor in one window, the views in the other 3 windows are thrown out of whack, sometimes jettisoning another view far off from anything in the scene so that it is a real chore to bring everything back to alignment. Is there a way to keep changing the 3D cursor in one view from affecting the positions of the 'cameras' in the other 3 views?
Comment: There's only one 3D cursor, so moving it in one, will move it in all the others, so are you asking for a way to make multiple independent 3D cursors?
Comment: @Lukaash I am fine with the one 3D cursor changing in all views, but when this happens each of the other three views move also, like their positions depends on the position of the 3D cursor.
Comment: @MrZak: I am not making any actions other than repositioning the 3D cursor. All I need to do to reproduce this is open blender, CTRL-ALT-Q to go into quad view, and then left-clicking anywhere in one view repositions the other three views along with the 3D cursor. I am using blender 2.77 as well. Could I have somehow introduced a nonstandard setting in my default UI?
Answer: In the View Panel, disable Lock to Cursor so that your view is not centered on the cursor:


Am I getting weaker?

Question: So after a few weeks of working out in my house, I've started to notice some gains. At first, I was glad that my exercises were efficient and continued to work out, which at the time seemed to get easier the more I worked out. I was certain that if I kept doing the same exercises, it would gradually get easier and easier, and I could move on to harder exercises. Now, I keep trying that same workout and I'm struggling with the push-up portion of it. For some reason, even with proper form and doing it fast, I lack the will and strength to do the amount I originally did. I'm 18 and I get about 1800-2400 calories a day with at least 50 grams of protein and 250 grams of carbs a day, as well as about 7-12 hours of sleep and minimum stress. I don't think I'm overtraining because I've taken at least 2 weeks off in the 3-4 weeks and don't push myself to particular hard exercises. So is it possible that I'm getting weaker despite physically growing, and if I am, how can I change this?
Comment: It's not clear what exercises you're doing, which would make a big difference in what to expect. Are you doing just light curls and a couple sets of push-ups?
Answer: There's a couple scenarios behind this.. I think the first 3 are the most likely..:

Hypertrophy(muscle gain) does not equal strength. In fact, it's possible to lose muscle while gaining strength, and gaining muscle while losing strength. It all depends on your workout, how many reps are you doing and what is your workout like?

Adaptation. If you do the same thing everyday, your body will adapt to those habits, and quit trying to adapt. In terms of working out, your body's adapted to the same exercises everyday and chemical changes are happening that are stunting your growth or backtrack your progress. It is usually not very severe unless you've been doing this for months, but mild strength loss is possible after a couple months.

Nutrition. You've given some details about diet, but are you getting all your vitamins, minerals, zinc, amino acids, EAAs and BCAAs? Eating complex carbs throughout the day and simple carbs before and after a workout? Feel free to bump up your protein.. I think 0.5 to 0.75grams of protein per lb of bodyweight is a good estimate..I don't know your weight but I'd shoot for 100 grams at least. Not an issue if you're doing 50 bit 50 is the bare minimum for health reasons, and not the best for mass or strength

Calorie intake-is your calorie intake the same as when you started?are your goals muscle gain or strength loss? You can weigh yourself each week and make sure your gaining weight each week to ensure muscle gain. Your body might just need more calories than it use to.

Too much sleep- 12 hours of sleep!? Having excess sleep has negative performance on he body ironically. I am not sure if this affects strength, but I do know it can lead to fatigue and depression.again, people don't think too much sleep is bad but it can cause fatigue.
Quality sleep-lets assume you're only sleeping 8 hours.. is that quality sleep? Even conditions like sleep apnea can turn 8 hours into 5 hours of quality sleep and cut REM cycles in half.
Water-staying hydrated?
Comment: To answer the first question, I do 3 reps of pushups and it's a full body workout I do 2-3 times a week. I know that I am getting enough nutrition in terms of minerals and other things and do eat carbs throughout the day, but my protein should probably be higher like you suggested. My calorie intake is superior to my original intake by about 500 and my weight is now 150 compared to 130. I will try to make my sleep more consistent at about 9 hours, but for the first half an hour I usually am just moving on my bed. I am hydrated through the day but sometimes forget when starting a workout.
Comment: I'd suggest changing exercises.  3 reps is more of a powerlifting rep scheme too.. I'd try to do other exercises and instead of focusing on reps, focus on adding weight if you can. Try to do other chest exercises, you should be able to use resistance bands if you can't afford much gym equipment.. you can get a near complete set online for about 60 bucks
Comment: Alright, thanks for the advice. I probably will take the rest of the break off to recover and then do other exercises and more weighted reps that are not pushups for a few weeks. I'll try to do my normal workout after a few weeks of doing a newer one and hopefully it'll be better, because I won't have to bother y'all with my questions. I might not buy the bands, because I did not want to spend any more money in quarantine, so I might just stick with body weight workouts and dumbbells, but I will consider buying them when I have a more stable salary.
Answer:
I've taken at least 2 weeks off in the 3-4 weeks and don't push myself to particular hard exercises.

When I take every other week off and don't push myself hard, I expect to stagnate or get weaker. This is especially true if my "on" weeks might only have 2 workouts.
If you want more results, put in more work.

Am I getting weaker?


How can I use py2exe with the OSGeo4W Python installation?

Question: I have a default Python installation in c:\Python27. I have also installed Python through the OSGeo4W installer, which has created a "sandboxed" Python installation with all the geospatial bindings I need. Now, I need to package a script using py2exe, but I can't figure out how to install or configure py2exe to work with the OSGeo4W installation. I have configured OSGeo4W to install external packages with pip, but py2exe doesn't seem to install with pip. If I try to use the downloaded installer, it only finds the system install in the registry. Any ideas how to get it working?
Answer: I've had better luck with pyinstaller than py2exe. It pretty much works out of the box for me with o4w python (you may need to install the optional python-win32 package). Follow the install instructions, and run the Build step. I didn't need to get into manually altering the spec file or even using options (other than --onefile for end user simplicity). Just make sure you run from inside the o4w shell so pyinstaller finds the right python environment. Here is my pyinstaller build batch file. There is only one line that does the real work:
python pyinstaller.py --onefile --out=%path\to\distrib%\myexe-%rev% %path\to\my\file.py%

Not to say py2exe can't work, it's just been so long now I no longer remember where I ran into difficulties with it or what the possible solution routes were.
Comment: Thanks, matt, this is a good alternative option and I'll give it a try.
Comment: I ran into a snag with this approach: pyinstaller needs pywin32 to work on Python 2.6+. Fortunately it can be installed using the o4w setup program.
Comment: I added note re: python-win32 requirement, thanks rudi
Comment: As a followup, I managed to create the exe without any problems using this method. When it came to running the executable, I kept getting `ImportError: No module named _gdal`. I thought it was a problem with the pyinstaller hooks, but it seems it's actually an environment issue in OSGeo4W, since I could get it to work fine from a regular `cmd` prompt (ie not o4w shell) as long as the `GDAL_DATA` environment variable is set. I wrote more on this at [StackOverflow](http://stackoverflow.com/questions/12698348/cant-get-pyinstaller-hooks-to-work-with-gdal).
Answer: I was able to get py2exe to work using a suggestion from wildintellect on IRC. After installing py2exe on the system python, I checked the install log (c:\Python27\py2exe-wininst.log) and copied the files into the o4w python installation (c:\OSGeo4W\apps\python27\lib). Basically, that meant the following files and directories:
C:\Python27\Lib\site-packages\py2exe-0.6.9-py2.7.egg-info
C:\Python27\Lib\site-packages\zipextimporter.py
C:\Python27\Lib\site-packages\_memimporter.pyd
C:\Python27\Lib\site-packages\py2exe

I also had to copy these DLLs into C:\OSGeo4W\apps\python27\DLLs to get it to link properly (basically I searched the c:\windows directory and copied across whatever caused it to fail):
msvsp90.dll
msvcr80.dll

There may be reasons why this is a bad idea, but if you are set on using py2exe, then this seems to work.
Comment: 2 days...good to know. Also, no matter who gets the credit, at least we all have another osgeo4w problem solved! I am sure you are not the only one who wants to use py2exe.
Answer: one option would be to add the osgeo python to your windows registry:
http://effbot.org/zone/python-register.htm
this site also contains information on how to remove it from the registry if you so desire.
I am pretty sure this will help you as long as you have admin rights to the registry.
Comment: Please see [add/remove the o4w python to/from Windows registry](http://trac.osgeo.org/osgeo4w/ticket/114) on osgeo4w website for an improved version of the effbot recipe, made specifically for o4w.
Comment: Thanks, that would work, except for the following: "Note that there can be only one registered interpreter for each major Python release (e.g. 2.0, 2.1, 2,2 etc)"
Both are 2.7
Comment: I was envisioning using it temporarily. ie. taking the C:\python version out of registry and using osgeo\python and then switching back later...best I could think of :)
Comment: I should have looked there first! thanks mattwilkie


Algorithms for Anomaly Detection of Event Sequence Data [Python/R]

Question: I am building an anomaly detection system of event sequence data (transactions). For each timestep, a transaction can be in any of 76 different stages.
My dataset is therefore a 3D array of size(m,t,N).
m is number of samples (~40 000), t = the length of the longest transaction (I am zero padding all other sequences of shorter length), N is the number of possible events at each timestep. $x_{m,t,N} = \{0,1\}$ where $x_{v,u,w} = 1$ if transaction v is in event w at timestep u otherwise it's 0.
So far I have created an LSTM Variational Auto Encoder in Python with Keras and doing outlier detection by applying Local Outlifer Factor on the latent representations of the transactions. It's based on this paper https://arxiv.org/abs/1906.10896 and following various blogs such as https://blog.keras.io/building-autoencoders-in-keras.html.
I would like to compare the results with other techniques. I was wondering if anyone has any other suggestions on algorithms and techniques for anomaly detection in unlabeled event sequence data?
Answer: You might be interested in sequential association analysis/sequential rule mining or time-aware attention (note the latter paper is written for the electronic medical record context, but the ideas should be transferable)


How to extract Software Update in macOS 10.14?

Question: I have 4 macs. Every time when there is an update it means I have to download 2-3GB of software update across all my macs. This seems inefficient at best. Is there a method to extract software updates and install to other macs offline?
Answer: It seems to me the main goal here is that you need to regularly update multiple Macs and you'd like to do that without having to download them each time for each machine.
I see two potential options here:

Use content caching
Download from Apple's website manually

Content caching
According to Apple:

Content caching is a macOS service that helps reduce Internet data
  usage and speed up software installation on Mac computers, iOS devices
  and Apple TV. Content caching speeds up downloading of software
  distributed by Apple and data that users store in iCloud by saving
  content that local Mac computers, iOS devices and Apple TV devices
  have already downloaded. The saved content is stored in a content
  cache on a Mac, and is available for other devices to retrieve without
  going out over the Internet.

Source: Apple - About content caching on Mac
In essence, you can enable Content Caching via the Sharing preferences pane in System Preferences to manage content caching on your Mac and select the items you want cached. Once cached, other Macs on your network can use this to perform updates from.
Refer to About content caching on Mac and Manage content caching on Mac on Apple's website for more info.
Download updates manually
You can download all updates directly from Apple by pointing your browser to: https://support.apple.com/downloads
From there you'll see the most recent software updates available for download, and you can also use the buttons at top to browse downloads by product. There's also a search field you can use to conduct specific queries.
Downloads will be in the <code>.dmg</code> disk image format and you can then keep and use these as required on your multiple Macs.


Transition from LaTeX to Plain TeX

Question: For several reasons I need to typeset in Plain TeX, however I have always worked with LaTeX. So how hard will this be? I basically need something like the book or report documentclass (with toc, chapters, sections, Theorems, ..., appendices, index, bib, ...). Most of the things I have learned about LaTeX have come from examples, can somebody direct me to a complete example of a book typeset in Plain TeX?
Comment: Well, there's the TeXBook itself, typeset entirely in Plain TeX. Same goes, I believe, for all other books written by Don Knuth himself.
Comment: AMS-TeX is based on plain TeX, so might be consulted for reference.  it's included in TeX Live, so `texdoc amsguide` would give you an idea of what's included.  the source for this guide should also be in TeX Live, and it was prepared using AMS-TeX, so it can be viewed (loosely, since it's more like an extended article than a book) as a model.  unfortunately, the documentation on the document-related macros (mostly in `amsppt.sty`) is sketchy, and as noted elsewhere, there is nothing like LaTeX's automatic numbering, cross-referencing, contents, or indexing facilities.
Comment: As reference for the TeXBook, see [`texbook.tex`](http://mirrors.ctan.org/systems/knuth/dist/tex/texbook.tex).
Comment: You might be interested in [Eplain](http://tug.org/eplain/).
Comment: @Mico It's a bit more complex than that because _The TeXbook_ uses a lot of additional macros on top of plain, collected together as `manmac`.
Answer: Plain TeX does not provide the 'pre-built' structural concepts which LaTeX provides, such as TOC, sections and so on. Instead, it provides the basic typesetting mechanisms from which you can build these up. As mentioned in the comments, Knuth's The TeXbook is not only the definitive reference for TeX but also a guide to how to create a book using plain TeX, as the source is available for examination.
It's clear from The TeXbook that Knuth expected authors to create a suitable bundle of support macros for each document they create. He does this for The TeXbook in a file called manmac.tex which is then used with the plain format to provide the necessary layout and so on for the book.
Some parts of this process are easier than others. LaTeX works hard to make life easy for authors in some places, for example automatically constructing a table of contents from sections using the .toc file with a two-pass workflow, or providing the \label/\ref system via the .aux file. Setting these up by hand is non-trivial, and it is notable that Knuth does all of these things by hand in The TeXbook.
Depending on the exact requirements, creating a document in plain TeX may require quite a bit of TeX programming experience. The eplain set of macros are often recommended to allow plain TeX to use the LaTeX mechanisms for dealing with some driver-dependent work such as graphics.
Comment: The question does not give detail of the reasons to require plain TeX here, and so it is tricky to know exactly what features are required. I've tried to cover the general points.
Comment: @Altermundus: Plain-tex – or should I say Plain-XeTeX (plain-tex format with XeTeX) doesn't have a problem with Finnish at least, neither with UTF8. I suppose the same applies to plain-tex format with LuaTeX, or should I say plain-LuaTeX. My point is, Unicode support (and via that, foreign language support) depends on the *engine*, not on the format (as much, anyway). Dunno about French, tho. Doesn't `\uselanguage{french}` work properly?
Comment: You can add to the general points, the problem to use a foreign language (build a format to use french hyphenation is not easy), the problem to use utf8.
Comment: @morbusg From memory, I think the set up in TeX Live is that `tex` is always created with only US hyphenation, but `pdftex`, `xetex`, _etc._ use the same hyphenation set up as the LaTeX formats. So if you want to really stick with Knuth's TeX you still have to compile your own format to get internationalised hyphenation.
Comment: @Joseph: I don't see anyone mentioning Knuth's TeX? Or do you mean Altermundus' comment? I mean, I myself use plain-tex format with XeTeX, and the point I was trying to get across was that the used format is a different thing entirely from the used engine.
Comment: @morbusg I'd interpret 'plain TeX' very narrowly, to mean Knuth's engine and format. The hyphenation patterns loaded into the format depend on the way you build your format file: it's the same `.tex` file for `tex`, `pdftex`, `xetex`, _etc._ but with different configurations. So it's not the engine _per se_ that determines this, but choices made when setting up the format-building system. (UTF-8 is different as XeTeX and LuaTeX are fundamentally different to TeX and pdfTeX.)
Comment: @Joseph: Now that's not fair. It's like saying "I'd interpret 'Linux' very narrowly, to mean Slackware Linux". `;-)` Regarding the latter, that's what I was getting at with the "(as much, anyway)".
Answer: Try to grab a copy of TeX for the Beginner by Wynter Snow. She teaches you how to handle the basics of Plain programming (regardless of engine: she explains ClassicTeX) and makes frequent cross-references for the experienced LaTeX user. You may use some of her macros together with eplain to mimick some functionality of LaTeX. And if you want to handle multiple languages, or at least something other than US English, try Enrico Gregorio's hyplain, available at CTAN. Make sure you know how to make your own formats.

Transition from LaTeX to Plain TeX


what's the best way to handle tag edit-warring?

Question: A user has just detagged a question I tagged. I haven't retagged: I suspect that this user would be all too happy with an edit war. It seems terribly trivial, but I've bumped into this user's snarkiness on more than one occasion previously. There didn't really seem a flag that was appropriate, other than "other", so I thought I'd solicit opinion here on the best way to deal with it.
Answer: I find myself uncertain that the tag renewable-energy has a lot place on a physics site, browsing the current list of question so tagged suggests that many of them are

Really technology questions with little physics content. Presumable they were asked here because their authors could find no better place.
Often very basic.
Only connected to renewable energy by motivation---I mean, the asker was
thinking about a renewable energy application and that brought up a physics question but the question isn't about power generation as such.

In this case we seem to be looking at conditions 2 and 3. The only part of the question that is not physics 101 work is getting an estimate of the solar magnetic field strength and variation in the neighborhood of Earth's orbit. Basically this is a blue sky speculation by someone with little formal preparation; fun but not very enlightening.
I think the question has a place here, but the tag is marginal on this question.
Comment: Thanks, I appreciate the feedback. I understand that the degree to which "physics 101" questions are appreciated here is the subject of some debate. I agree that many of the existing renewable-energy questions are as much about technology as about physics; perhaps once the Green Energy site gets launched and comes out of beta, we can migrate them all from here to there.
Answer: Are you more interested in how to handle tag edit wars in general, or just this specific one? If you want in general, what you did was best - do not reciprocate or rollback, and start a Meta discussion to get things settled with proper discussion.
If you want specific feedback, well, dmckee has that for you. ♪
Comment: Thanks. Well, both really I guess. So I'm a happy bunny now.


How to say "You may return to your seat" in polite way

Question: How does a native English speaker say "You may return to your seat" in polite way? I've ever heard my lecturer said, "you may return to your expected chair." But I'm not sure about the "expected" part, maybe I heard it wrong.
Comment: "You may return to your expected chair", while grammatical, is a very strange thing to say. I can't think of any circumstances in which I would expect to hear it.
Answer: I'm not going to claim to be a native English speaker (although I speak and write in English much better than my own mother tongue), but this is a line I've often heard being used:

Kindly return to your seat.

Or

Please return to your seat.

The statement you wrote,

You may return to your expected chair.

also appears to be grammatically right, but as commented earlier, it's a very odd expression...


English - Acceptable use of parentheses in an author's name

Question: My legal name is Barbara but I have gone by Babs since I was in the 4th grade.  I have written a children's book and wanted to list my name as Barbara (Babs) but my editor said that it might not appear very professional.  She has never heard or seen anyone use parentheses as an author.  Would the use of parentheses in an author's name seem amateurish?
Comment: Usually a nickname would be written like: Barbara "Babs" Surname. However, I am curious as to your reasoning for including Barbara at all if it is not what you want to be known as?
Answer: If your editor says something might look unprofessional, you should listen to your editor. Your editor is a professional, whose task is precisely to make your work appear at its best. We, on the other hand, are a bunch of internet amateurs with good intentions.
As @ArkensteinXII mentions in a comment, if you wish to go by "Babs", you can go by "Babs", no need to include "Barbara" at all. As an example, Sir Terry Pratchett always used "Terry Pratchett", never "Terence David John Pratchett", not even "Terence Pratchett".
Comment: Seconded. I would also add that you can have your nickname on the cover as Babs Surname, or even a complete pseudonym, and your legal name can still appear on the copyright inside the book. You can also have an "about the author" section where your bio can say *Barbara "Babs" Surname is blah blah...*
Answer: Edward Elmer Smith is not well known but E. E. 'Doc' Smith certainly is, punctuation and all, among the right classes of science fiction fans.
As other people have said, brackets may look odd but if you want to go by a nickname then there seems to be no reason not to - though your editor is the expert here.
Comment: I am sorry that I have to downvote this answer, but it contains false information. E. E. 'Doc' Smith may have been "known to his fans" by that name, but he began publishing under his given name as Edward E. Smith. As far as I know the fan name was only used on book covers after his death.
Comment: It's worth the downvote for the extra knowledge so thank you.  Indeed, looking through various publications, I see he was usually Edward E. Smith PHd.  Correction noted.
Answer: The given name I've been known by since High School is not the same as the name on my birth certificate or driver's license, but it is, like yours, a known nickname for my legal name.
I used to use my legal name on nearly every document but, starting a few years ago, have started using my nickname instead.  My legal name is still on my identity documents, bank accounts, taxes, and medical information.
Anything I've published in the last few years uses my nickname.  When I signed the contract for my story that's coming out next month (so we're told!), I used my legal name, but my byline is the nickname.
For example, take one of my favorite authors.  Her legal name is Constance Elaine Trimmer Willis and her pen name is Connie Willis.  She doesn't hide her full name but there's no need for her to make it obvious in her work.
Don't use parentheses, it's just not done.  Use the name you want.  If you find yourself needing to use your legal name in a place other than a document, you can put your nickname in quotes, as Arkenstein XII has suggested, but that would be more for the author of the piece about you to decide.  It would never go on the book.
Answer: Anything goes.
Musicians often use unconventional pseudonyms, from Royce da 5′9″ to , but sometimes writers use uncommon punctuation or orthography as well.
There's a German crime author who published his books under the pseudonym -ky:

But these cases are rare – in fact I could not find another contemporary example, only 19th century writers such as Abbé *** or El…y –, and for a writer publishing today I agree with what @Galastel says.
Barbara (Babs) Surname and Barbara "Babs" Surname sound unprofessional to me, and I have never seen the name of any author represented in this way on a book cover.
I would do the following:

In your author bio, both on your website and in your books, call yourself Babs (and do not mention your full name Barbara there at all). E.g. "Babs Surname lives in Kentucky with her husband and three dogs. She..." Everyone knows that Babs is a common nickname for Barbara, and everyone will be able to understand that Babs refers to the Barbara on the book cover and in the website headline.
Sign all posts and comments in your blog and on social media with Babs.
When you are interviewed, ask the interviewer to "please call me Babs. Everyone does."

Soon readers and reviewers will pick up your nickname.
I wouldn't use Babs Surname as your author name. Bob Surname, Kate Surname, or Bill Surname all work well as authors' names for Robert, Katherine, and William respectively, because they are also common as full given names, while Babs (to my knowledge) is not, or at least not a common, given name in itself.
Answer: The conventional way to write a nickname is in quotation marks between the first name and the surname.  For example, E. E. "Doc" Smith.
Either Babs Benge or Barbara "Babs" Benge works, but I'd go with the first, myself.  A lot of people publish under a nickname or middle name.


Benro Tripod: Sticky Middle Column

Question: I've recently purchased a Traveler Angel II (Aluminum) and have noticed that when I remove the middle column in order to reverse it or attach to the monopod leg, it sticks (in the beginning) when trying to put it back in its own place, so I have place my finger beneath the reel inside so that the column would move in properly. Is it normal, or is a flaw?
Answer: It's hard to know whether it's normal or a flaw.
Does it interfere with your ability to use it properly?  Eg, to either transport or set it up, or to take photos?  If so, it sounds like it's something that's worth getting looked at.
If it doesn't really interfere with anything, other than being a slight annoyance, then it's up to you whether you think it's worth taking it further.  You could always contact whoever you bought it from.

Benro Tripod: Sticky Middle Column


Trying to extrude and bevel a symbol on a curved path

Question: I have been following a tutorial on how to make a curved, 3D film strip but I cannot get the strip to become 3D and extrude and bevel on a curved path. I create a curved line using the pen tool then click Effect-->3D-->Extrude and Bevel. I fix my settings, Map Art to the symbol I created, then click No Shading, and then OK. All I get is a curved line with a bunch of dashes as shown. Anyone know what's going on?
Answer: Probably you are mapping the art to one side or back side instead of front of the mesh.
You must play with the angle.
Map Art to the lighter mesh. That is the front view.
See the image below:
Comment: I keep rotating it around but I still get those dashed lines in the preview. What do you mean by Map Art to the lighter mesh?
Comment: I added another screenshot above to show my preview
Comment: Look at my Map Art panel. In surface, my front mesh is 5 of 7. If I put in anther one like 1 of 7, it maps my symbol to the backside of surface, showing just a dash. Click the triangles to view a lighter surface, not the greyed ones.


Philippine passport holder stop over in Vancouver Canada

Question: I hold a Philippine passport, with a C1 visa (transit visa to US). I had booked flights traveling back to Manila from Barbados.  My iterinary is from BGI to JFK, then on JFK New York then Cathay Pacific. I still need to stop over in YVR - Vancouver - Canada before heading to Hong Kong. Do I still need to have a transit visa from Canada , even will just stop over for 3hrs just to pick up passengers from there and heading to Hongkong?  Or am I eligible to TWOV transit without visa as holding a Philippine passport and have a C1 transit visa from US.  Thanks in advance.
Answer: Yes, as you hold a Philippine passport and you are transiting to/from the US, through Vancouver airport, arriving on Cathay Pacific (one of the approved airlines), and you entered the US on a US visa and you did not overstay, you qualify for the Transit Without Visa program which means you can transit Canada without a visa.


Which biome has the most plants on it?

Question: I'm trying to gather plant fibers to make a bunch of bandages. However I can't seem to find  a biome with big plants on it. Which biome has the most plants on it for farming plant fibers?
Comment: Grasslands I'd imagine.  Forests might be a good bet too.  Or, if you aren't terribly picky, just head underground and cut down a bunch of roots! They're great for plant fiber.
Comment: I've had luck in forest biomes. They have small plants on the surface you can destroy with a single weapon swing that yield 1-2 plant fibers. Haven't verified but I believe they re-spawn as well.
Answer: The jungle biome has the most surface plants in it, which can be easily broken by a weapon to yield plant fibers. My preferred way to gather fibers is to just run along the surface of a jungle planet swinging a fast weapon.
The other best place to get plant fibers is to find a forest planet with a toxic biome. The trees in toxic biomes are tall flowers which, when cut down, drop plant fibers instead of wood.

Which biome has the most plants on it?


Does a Vcc layer cause noise to a 4-layer RF PCB?

Question: I'm designing a 4 layer GPS tracker PCB with the 2nd layer as ground and 3rd as Vcc. Is this a good practice? I know a gnd layer is good but I'm not sure how to distribute the positive of the supply on the 3rd layer. Should I cover the whole layer with the supply even underneath the antennas? Or just pour Vcc underneath the Vcc pins?
Comment: I think it depends to power plane noise. If your power plane is not too noisy and not carrying high current voltage on that plane,  you may cover whole layer with Vcc.
Also using gnd-Vcc planes on consecutive layers is a good thing. It generates capacitance between layers and acts like decoupling capacitor.
Comment: Probably it will depend mostly on what you connect Vcc to. If you get noise backwards from the circuit into the Vcc plane, you'd probably want that noise to go towards the Vcc regulator and not towards other circuits. Consider for example if you have 5V layer, from which you connect a 3.3V switch regulator but also 5V logic. If the 3.3V regulator is noisy, you don't want that noise to get passed to the 5V logic circuits. Though of course the proper solution to that is to address the root of the problem where the noise originates from (and in addition decouple each IC supply).
Answer: Planes are often used to ensure that RETURN paths are available for fast edges, to constraint radiation (for EMI control), to achieve clean waveforms.
If your fast edges are from logic UP edges, then the logic VDD is providing high currents that will demand return paths.
You can use local and tiny ceramic capacitors from the VDD pin of the IC, to the GROUND plane. No need for that plane IMHO.
But you'll have to do a bit of thinking. And sketching the return paths. In exchange for this effort, you free up that "VDD plane" for many other valuable uses.
Comment: "to constraint radiation (for EMI control), to achieve clean waveforms" You make it sounds like just using planes everywhere on a circuit board will give you these two results which is completely untrue. Please clarify your answer to add-in more details why a VCC plane would give you such end results. "If your fast edges are from logic UP edges, then the logic VDD is providing high currents that will demand return paths" How did you come up with this from the original question? A GPS system is usually very low-current. "You can use local" Sorry to say this means nothing...


Installing MOM 2005 agents on Windows 7

Question: I'm trying to get the agent to install on the Windows 7 test box I have here, and it's a no go, says the RPC server is not available. The only thing I found out there from M$ is that MOM2005SP1 isn't supported on Server 2008 R2 or Win7, but is on Server 2008 with a hotfix. Has anyone been able to find a workaround to manage Win7 clients, or should i just consider a move to SCOM 2007?
Answer: As Server 2008 R2 and Windows 7 are explicitly not supported by MOM 2005 SP1 (as per http://support.microsoft.com/kb/953140) which was released over 4 years ago on August 1, 2005... I'd say it's about time to start transitioning to SCOM.
Comparison of the features of MOM 2005 and SCOM here: http://www.microsoft.com/systemcenter/operationsmanager/en/us/compare-products.aspx
Disclaimer: I work for Microsoft, although not for the System Center team, nor in a sales role.  Recommendations/opinions are my own. :)
Comment: I've installed SCOM and begun testing, thanks for the advice.
Answer: MOM2005 console runs on windows 7 client
There is no agent to support windows 2008 servers, only windows 2000 and 2003
It's a good method to Microsoft to say "buy scom2007"
In this case, you must change your master server, your db and update all clients
My advice, change to Nagios
Comment: Problem is long since solved, and I'll pass on anything non-windows based for monitoring.

Installing MOM 2005 agents on Windows 7


How to achieve image and video stabilization when the camera does not have it?

Question: My camera (Nikon D5600) does not have in-body image stabilization. Even the VR kit lenses seems to be of no use to tackle shakes. I can use Tripod wherever possible but want to know how other methods being used by professional photographers. Which software is best in post-processing ?
Comment: "... how other methods being used by professional photographers". There aren't any widespread "other methods". Pros use the proper technique, including proper camera stabilization hardware, to reduce camera movement during exposure, not after.
Comment: shoot wider angles; they show less motion and have deeper DoF.
Comment: Video is off-topic here, see https://video.stackexchange.com/
Comment: OK. This is with regard to photo as well.
Comment: Assuming this question is related to using long telephoto lenses, see: [When are special long lens techniques necessary for sharp wildlife photography?](https://photo.stackexchange.com/q/85735/11924)
Comment: Have you analysed why you are seeing so much camera shake? What environment are you shooting in/from? Have you investigated stabilising hardware other than tripods?
Answer: For longer focal lengths, such as 600mm at the long end of the lens you asked about in another question, properly implemented lens based stabilization is more effective than sensor based stabilization. That's assuming all else is equal, which it rarely ever is. But they're usually equal enough to maintain the principle. The reason this is the case is that the same amount of camera movement with a lens having a very narrow angle of view causes the blur to travel further across the frame than with a lens having a wider angle of view.
On the other hand, all else being equal, camera based stabilization works better with wider angle lenses. But the effects of the same amount of camera movement is not as great at wide angles as at narrower angles of view. Unless we're trying to shoot at insanely long exposure times while hand-holding it's not nearly as important to have any kind of stabilization with a wide angle lens as compared to a long focal length lens. If anything in the frame is in motion, the subject motion will be the limiting factor long before lack of IS will be at short focal lengths. Neither in body nor lens based stabilization do anything to tame subject motion. Only shorter exposure times can do that.
Shooting anything beyond about 300mm on a full frame (about 200mm on an APS-C body) requires improvements in the user's technique to get good results compared to shooting at shorter focal lengths. There's a real learning curve involved. It's probably even a bit steeper than the one when jumping from a fully automatic small sensor point-and-shoot type of camera or even a phone camera to your first larger sensor interchangeable lens camera.
We have a few existing questions here that address shooting with long focal length lenses:
View (in EVF) keeps moving after taking a shot with telephoto lens
Do my photos look blurrier on a newer, higher-resolution camera body because my lens has a problem?
Nikon D3300 - Trouble Focusing on Birds both Stationary & Moving
Sigma 150-600mm vs 300mm prime with extender?
We also have a few existing questions about processing blur out of an image after the fact. Essentially, it's a lot of effort for not much in return.
Is it possible to fix severe blur from camera shake after the fact?
How can slightly blurred photos be improved in post processing?
Can anyone recommend *freeware* to reduce motion blur by deconvolution?
What plugin for Photoshop can I use to remove camera-shake blur?

I can use Tripod wherever possible but want to know how other methods being used by professional photographers.

There aren't any widespread "other methods". Pros use the proper technique, including proper camera stabilization hardware, to reduce camera movement during exposure, not after. For pros time is money. Preventing camera movement is much easier and less time consuming than partially correcting it after the fact.
Comment: @RKh a video stabilizer does something very different: it removes movement between frames. it does not reduce blur in individual frames, if fact, blur can become more noticeable (since motion blur when the camera is moving is perceived as natural, but when the movement is removed, the blur is still present.)
Comment: I tried a Video Stabilizer app for videos but for Photos, there is no tool.
Comment: @RKh Video is specifically off topic here when also not applicable to still imaging.
Answer: In-lens VR is almost as good as in-body, if the lens system is good enough [they vary]. You ought to be able to see it switch on as you half-squeeze [it's on full-time in live view].
Nothing can really fix shake post-pro in stills, just use faster exposure times. Though some apps will have a go, it's rarely useful.


Term for cousins whose parents were related by marriage?

Question: My father and his brother married two girls who were first cousins to each other.  I know that the children from these marriages are not 'double' cousins, but they are genetically closer than simple first cousins.  Is there a term for this relationship?
Answer: Aside from the generic "kin", the overly specific "first cousins through their fathers, second cousins through their mothers" and their consanguinity (15.625%) being slightly higher than for otherwise unrelated first cousins (12.5%), not really; at least not in English. For that matter, not in any other language I know, but there easily might be one which has a specific term for this kind of relationship.
Comment: As a side note, that's the same relationship Albert Einstein had to his second *wife* Elsa Löwenthal née Einstein


Reverse Geocode latitude longitude with Geotools using Natural Earth Shapefiles in Java

Question: I am trying to perform reverse geocoding in Java using GeoTools and Natural Earth Shapefiles. I just want to pass latitude longitude and get the corresponding country name + state name. I have searched entire internet and all the posts on this forum but couldn't find an answer for my specific use case. I am not sure how to pass the latitude longitude value and use Natural Earth shape files to get the country name and state name. I don't want to display anything on the map. Just the country and state name would be enough.
Answer: I'm not entirely clear on which part of your question you can't find an answer as all of these steps are pretty well documented on this site (mostly by me :-)) as well as in the tutorials and documentation. But here you go, first open the shapefiles and store the features in a memory store:
  SpatialIndexFeatureCollection countries;
  final static FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
  final static public String countryFile = "/data/natural_earth/10m_cultural/10m_admin_0_countries.shp";

  public SimpleGeoCoder() throws IOException {
    // load the country shapefile
    URL countryURL = DataUtilities.fileToURL(new File(countryFile));
    HashMap<String, Object> params = new HashMap<>();
    params.put("url", countryURL);
    DataStore ds = DataStoreFinder.getDataStore(params);
    if (ds == null) {
      throw new IOException("couldn't open " + params.get("url"));
    }
    Name name = ds.getNames().get(0);
    countries = new SpatialIndexFeatureCollection(ds.getFeatureSource(name).getFeatures());
  }

Then create a lon/lat point (as Natural Earth stores its coordinates in that order):
GeometryFactory gf = new GeometryFactory();
Point london = gf.createPoint(new Coordinate(0.0, 51.0));

Finally look up the the point in the stored features:
 public SimpleFeatureCollection lookup(Point p) {
    Filter f = ff.contains(ff.property("the_geom"), ff.literal(p));
    return countries.subCollection(f);

  }

Then print out the name (or other attributes):
SimpleFeatureIterator itr = features.features();
try {
  while (itr.hasNext()) {
    SimpleFeature f = itr.next();
    System.out.println(f.getAttribute("NAME"));
  }
} finally {
  itr.close();
}

I've put all the code into a gist for you to download. Adding administrative sub units is left as an exercise for the reader.


Which google scholar citation format is IEEE standard?

Question: When I want to use formatted citation from google sholar it;s show 5 option to copy. Which one is IEEE standard? I add an image for clear my question.
Answer: None of the "standard" citations that they provide is IEEE format.
Instead, you should use one of the links at the bottom to take the format for your preferred citation manager, such as BibTeX, which can then be used to format following any publication venue's guidelines.
For IEEE in particular, the best option is generally BibTeX, because IEEE strongly pushes its authors towards preparing their publications via the IEEE LaTeX package and its accompanying BibTeX style format.
Comment: @Razik If you're working in Word, I believe that EndNote is the preferred format.  IEEE does support Word, but it's an awkward fit, and if you make the investment in LaTeX it will likely make your life easier in the long run.  If you're close to deadline right now, of course, it's probably better to stick with Word for this paper and start the switch later.
Comment: Thank you for your answer. I am writing my first paper in MS word that's why I faced this type of problem.
Answer: Word supports the IEEE citation format already (at last Word 2016).
I would suggest using JabRef to build a BibTeX-file to keep track of your references. JabRef can export to the reference list format Word supports (an XML-file). It can also directly import the BibTeX-entires downloaded from Google. I suggest this program, as the built-in reference list editor in Word is nearly useless. Another alternative, if you are on Windows, is to use bibtex4word. This macro uses MikTeX or TeX Live to generate a reference list from your BibTeX-file which is subsequently imported into your Word document.
Answer: As the other answers suggested that none of the options are in IEEE format, I first went looking for an online citation tool for this purpose. I found one which does not require any login or premium account: Bibme. Another one is Refme. Yet another: Citation Machine. You might also want to search for other tools, as they are in plenty on the Internet.


what are "PSD to HTML" Jobs

Question: I'm a graphic designer usually do logo and banner design work. I recently got a work from my client to make PSD's for the website. So i want to ask that what exactly he will be expecting from me? I don't have a strong knowledge of html/css.
Comment: I'd actually ask the client to specify everything that I'm unsure about what he wants me to do. Sometimes clients use words they don't understand. I'm not saying this is the case here, but you'll know if you ask.
Comment: Many web sites don't even use PSD files as a basis any longer. It's often faster and easier to go straight to HTML/CSS markup.
Answer: PSD to HTML is the non-preferred way to go about designing and building web sites. The process is very waterfall-based. It's essentially:

Visual designer lays out everything in PhotoShop
Client approves it, then tosses the PSD over the fence to the dev team and says "deal with it"
Dev team "deals with it" and typically produces a bloated web site with poor interaction (and not necessarily their fault).

The problem with this process is that PhotoShop is not a dynamic canvas--but your web site is. A web page can be viewed in any number of web browsers, on any number of devices, on any number of differently sized screens, with any number of installed fonts, with any number of interactive inputs. PhotoShop can't really accommodate any of that properly.
The better way to handle it is to design with the code in mind from day one. This is more of an Agile process.
All that said, if the client has asked you to create the PSDs, then go for it. You have the easy part. Unfortunately, there will be some developer down stream that will hate you for it, but by then hopefully you've gotten your money and ran. :)
Comment: Funny answer. :o)
Answer: PSD to HTML means that you are going to convert PSD into HTML. Give them working HTML + CSS + JAVASCRIPT. But if the client gave you a job to create PSD for the website, as per your question, all you need to do is create a PSD and let somebody else do the conversion.
Comment: @Ahmed: About your question on what to charge: http://graphicdesign.stackexchange.com/a/959/306
Comment: so its just an idea that i'll be giving to them. Does layers are of any importance here? I mean can i even design in the coreldraw as well(I'm better on it)?
Comment: Depending on the developer that is going to work with it later, I prefer layered photoshop, some developers don't use Photoshop so JPEG or PNG will suffice. Also you might need to cut the JPEG/PNG depending on your design.
Answer: Take that job and make a good looking webdesign in Photoshop, then send me the PSDs doc , i'll convert them into HTML CSS as I am expert in this field. Contact me at Skype my id is arlalsaehl . you and me can make a team. Thanks.

what are "PSD to HTML" Jobs