Can you help me locate the post Stephen Kitt answered / commented on in last 2 months about the best recovery software - he listed 2 options?

Question: I read a post about 2 months ago, maybe less, that Stephen Kitt commented on or answered about best recovery software. I have searched under his posts, but am unable to find it. Should I ask the question myself? Is there anyway to make sure he sees the question?
Comment: [This](https://unix.stackexchange.com/a/207968/116858) may possibly be the answer that you refer to?
Comment: @Kusalananda No, but it did mention one of the 2 recommended ways which is helpful.
Answer: No, there is no way of making sure a specific user reads your post. You could leave a comment under one of Stephen's posts and ask them to check but that can be considered rude and a bit pushy. This isn't a social networking site.
But while Stephen is indeed extremely knowledgeable and helpful, he isn't the only expert on the site, and it's very unlikely he'll be the only user who can answer. He also spends a lot of time here, so it's very likely he'll see your post if you ask it anyway. So sure, ask your question and see what you get.
If, however, you don't need to ask a question but only find an existing one, I suggest you search in DuckDuckGo or Google or whatever search engine you prefer using site:unix.stackexchange.com to limit the results to here. The local search isn't very good, unfortunately.
Comment: Effectiveness of searching is why comments should almost never be removed (except some extreme cases, but still need great caution), regardless of whether converted to chat, or how many comments there are.
Comment: @Tim If you find a useful comment, suggest an edit to the answer. If you don't, the comment could not have been that useful. If the edit is rolled back or denied in some other way, then the comment was not useful to someone else, and you may have to make a note of the comment in some other way.  Comments are ephemeral and are _supposed_ to be ephemeral.
Comment: @Tim If comments are that useful, they should ideally be incorporated into the answer. Anyone with editing privileges may propose or make edits, and comments that have been dealt in this manner may be flagged as "no longer needed".
Comment: @Kusalananda The reality is: useful comments are  incorporated less often than not by anyone, and the view of usefulness varies differently from user to user.
Comment: @K: (1) Usefullness is very subjective. Even when  I don't see a comment useful today, probably due to my ignorance, I might change my mind when I revisit it in the future. I don't think I am alone. Denying access to a comment by removing it kills the possibility of revisiting. (2) It can be difficult to sell the point of incorporating comments into replies to  many users,  per their familiarity with the policies, and willingness to comply.
Comment: @Kusalananda  This profile says better than I do: https://stackoverflow.com/users/388520/zwol
Answer: Because I've run across this situation, here are two methods I've used.
First, one you've already tried: searching through a user's answers.

Go to the Activity tab of Stephen's profile.
Go to the search box at the top (which is prefilled with "user:86440") and adding "is:A recover" to search for Answers (is:A) containing the text "recover". Search.
On the resulting page, sort the results by "Newest".

The result is this URL:
https://unix.stackexchange.com/search?tab=newest&q=user%3a86440%20is%3aA%20recover
The best choice from that list looks like Restore a removed file when still in use.
Secondly, because Stack Exchange views comments as second-class citizens (there only to support the post they're attached to), there's currently no direct, on-site search method for them. Next-best is the Stack Exchange Data Explorer (SEDE) (that's the UNIX & Linux flavored link). The SEDE data is only refreshed weekly. There, you can construct SQL to query the data you're after. One example might be:
https://data.stackexchange.com/unix/query/1103627/user-comments?needle=%25recover%25&UserId=86440
which corresponds to this SQL:
SELECT
    Comments.CreationDate,
    Comments.Id as [Comment Link]
FROM
    Comments
WHERE
    Comments.UserId = ##UserId##
AND Comments.Text LIKE ##needle:string##
ORDER BY
    Comments.CreationDate DESC

Simply plug in the userID (seen above from their profile page) and the words you're looking for. SQL uses % for wildcard text, so a query string for a comment containing "recover" would be %recover%.
That query pulls up this comment from 2019-08-15 as the only match within the last two months.


Can I use tile sealant in place of grout?

Question: We placed our tile in mortar using the recommended tool and it squished up higher than intended and dried in the grooves of the tile sides because I ended up in the ER at the time it was supposed to be cleaned out. We have been trying to scrape mortar out of the mosaic tiles but it is extremely difficult. We thought about options, ie. Scraping mortar, ( how best to do so, I don't know. The tiles are as small as 3/4 inch, a daunting task), using a tile sealing caulk in place of grout since there is not much grout, tearing the whole thing out and starting over(the least desirable. Suggestions?
Comment: Is the mortar actually sticking up beyond the level surface of the tiles? Or, are you just concerned with mortar in between tiles? Or, is it both?
Comment: I think we would need to see a pic before you could get real advice.  The two answers are making a lot of assumptions.
Comment: You can use a manual grout removal tool, or a rotary tool with a diamond coated blade to grind it all out. It will take a lot of elbow grease, but would be cheaper than replacing your entire floor. Grout is really the best option.
Answer: This happens on every tile install at least a little. There's nothing wrong with some mortar squishing out. Now, if it's over the top of the tiles, that's another issue. If you think there's room for a caulking/grouted/sealant, then there's likely room for grout.
You can use a sealant in place of grout, but from my experience having done this before, the sealant attracts dirt which seems to stick to it vs. grout where you can just sweep dirt off your tiles. Also, the sealant is less durable to foot traffic and wear and it's a huge pain to put in.
Grout is just colored/sanded cement. It will adhere to your mortar that is already there. No one will be able to tell unless maybe you want white grout and your mortar is grey. I'd just use grout anyway and see how well it covers. And if you really think you need to remove some of the mortar from between tiles, you will make your life a lot easier by using a multi-tool with the proper vibrating blade attachment which is made for masonry. You can get a carbide masonry blade that will fit most of the common multi-tools. It's meant for grout removal, but it may help a lot for your situation as well if the mortar is sticking up really high.
Comment: Grout removal blades are great, as long as the spacing is wide enough. They also exist as attachments for a reciprocating saw, often found in the tile section of the big box stores. If you happen to hop out of the line when using any power tool, you're in trouble. When I have to clean a little bit of mortar, I just use a utility knife. (Yes, it dulls the blade quickly, and if you have a crazy amount to deal with you'll hate me for this advice. Snap off olfa style blades might be the most cost effective here.) Cut approximately down the middle first, then tidy the edges more carefully.
Answer: When you lie the tiles in a mortar generally speaking it is better quality; but when something goes wrong, like in your case problem is much bigger than it would be if you have just used a glue.Celaning splashed mortar of the tiles is REALLY hard, and plus you will most likely damage (scratch) your beautiful new tiles. Try using soft sponge and water and rub until your hands bleed :) but there is no guarantee. When it comes to sealing space between tiles (fugues) I don't see why not using grout or sealing caulk or products which are specialized for this purpose. If tiles are outside best would be to apply old technique: use fine mortar (cement and extra fine sand) that's how people did it in the old days before new materials. Now if your tiles aren't flat (horizontal on the floor and/or vertical at the walls) if there are "waves" I recommend that you replace them, or maybe you decide that it is acceptable and learn to live with it.


Getting Required license is missing: Runtime

Question: I am setting up Sitecore on Azure Web app PaaS.  I am using the official Sitecore packages to deploy a CD and CM role to azure.  These have been deployed as vanilla Sitecore instances with no additional changes, code or config from my application as of yet.  The packages are pre-configured by Sitecore to the azure setup, Redis azure search etc.
I am getting a Required license is missing: Runtime error when trying to load either the CD or CM role.  I have our organisational license file on the azure web app. I copied it onto the application using the Kudo debug console for now. The license has not expired.
I believe the correct license file location is being resolved because if I remove the file all together I get a FATAL Could not find license file: D:\home\site\wwwroot\App_Data\license.xml error.  The minute I replace the license file I no longer get this error but still get the initial license missing error.  Any idea why this could be,  could it be an issue with uploading the file via the Kudu tools or possibly some missing section from the license file itself.  This file is used on other projects without issue and on local development.
Answer: Check the file encoding. I heard someone mention at Symposium having issues with their license file in PaaS that was caused due to the way the license file had been uploaded mangling the text encoding so that Sitecore could not read it.
I believe the fix was to upload the license to the app service via FTPS using forced binary mode, or something similar.
Comment: Yes I think you could be correct,  I just deleted the file and created it again in Kudo manually and it was fine.


What is a TAPS combustor and how does it differ from any other annular combustor?

Question: I found out that the GEnx engine uses a TAPS (Twin Annular Premixing Swirler) combustor. Is it a single or dual annular combustor ?
Comment: Probably a duplicate of your other question: [What is the difference between single and dual annular combustor?](https://aviation.stackexchange.com/q/44869/3201). As you don't have yet selected an answer, you could just request about TAPS particularity in the same post.
Answer: See this question.  It is a single annular combustor (one ring of full nozzles).  I think that "twin" refers to the fact that within a single fuel nozzle, there are two different fuel streams: the main stream and the pilot stream.  This video might also help explain it a bit.


Too late to renew my Patent?

Question: My patent was due for renewal Dec 2019, year 8.  Is there any way I can resurrect it? Thanks in anticipation. Pat.
Comment: Do you mean you missed a fee payment? Patents are not renewable, but there are periodic fees due.
Answer: You can petition for acceptance of a late payment - from the USPTO web site -

A petition related to acceptance of delayed payment of a maintenance fee after expiration of the patent based on unintentional delay under 35 U.S.C. 41(c) and 37 CFR 1.378 (b) must be accompanied by:
a statement that the delay was unintentional;
payment of the appropriate maintenance fee; and
payment of the petition fee as set forth in 37 CFR 1.17,

Too late to renew my Patent?


Crust thick enough to prevent volcanos

Question: Could you have an Earth-like planet with a crust thick enough to prevent volcanos from forming?
Comment: As the core cools, volcanism will eventually stop.
Answer: It depends on the definition of Earth-like planet.
In terms of size, density and gravity Venus is very Earth-like, but in terms of atmospheric and  surface conditions and its axis of rotation, and period of rotation Venus in not Earth-like.
I will assume you mean a terrestrial or rocky planet similar in size to Earth.
Earth's crust has two subdivision: oceanic and continental. Oceanic crust is between 5 km and 10 km thick whereas continental crust is between 30 km and 50 km thick:

Oceanic: 5 km (3 mi) to 10 km (6 mi) thick and composed primarily of denser, more mafic rocks, such as basalt, diabase, and gabbro.
Continental: 30 km (20 mi) to 50 km (30 mi) thick and mostly composed of less dense, more felsic rocks, such as granite.

Earth's crust is fractured into plates as described by plate tectonics. The boundaries of some plate collide causing uplift in the collision zone. The Himalayas is an example of such a zone. At other boundaries one plate subducts underneath the other plate. It's at these boundaries that most of Earth's volcanoes form.
For plate tectonics to occurs large amounts of water must be present to lubricate the subducting plate. The implication of this is that for plate tectonics to occur large oceans need to be located near subduction zones.
The other type of volcanoes that can occur are intraplate volcanoes which are located far from tectonic plate boundaries in the interior of tectonic plates. Such volcanoes are thought to arise from mantle plumes.
Earth has a diameter of 12 740 km, and Mars has diameter of 6780 km.
The crust thickness of both planets is 5-50 km for Earth and 10-50 km for Mars.
The ration of maximum crust thickness to diameter for both planets is 0.003925 for Earth and 0.007375 for Mars. The ratio for Mars is nearly double that of Earth, yet the Olympus Mons volcano on Mars is larger than any volcano on Earth.
For volcanoes to form, the temperature of the magma must be high enough to melt a hole through the crust and the pressure within the magma chamber must be high enough to overcome the resistance to flow posed by the friction of walls the volcanic vent and the gravity of the planet.
All terrestrial planets will experience volcanism at some period during their formation, it is a matter of when volcanism stops and why. Volcanism on Mercury ceased early due to the planet contracting early in it formation. Even the Moon experienced volcanism.
Answer: Depends on how Earth-like you want it to be. On Earth, most parts of the crust do not support volcanoes. But because we have active plate tectonics, there will always be places where plates slide beneath each other (subduction zones) or where they slide apart. Volcanoes are unavoidable in these locations, I think. A planet without plate tectonics could be volcano-free, but perhaps not for the entirety of its history. Mars has no active volcanoes, but it used to; it's lost much of its internal heat since then.
Comment: Plate tectonics are no pre-requisite for volcanos. Plumes are much more stable than the plates themselves. You see that nicely in volcano chains like for Hawaii or the Kermadec island chain where the plates move over the volcanic hot spot. Crustal volcanism is only one kind of volcanic mechanism.
Comment: Sure, I was just saying that if you _have_ plate tectonics you're going to have volcanoes.
Comment: Your post start reads the reverse though (at least to me): "most parts of the crust do not support volcanos" can IMHO only be understood that crust is a prerequisite (unless you refer to isostasy - but that'd be quite beside the point of the question).

Crust thick enough to prevent volcanos


Can't print to HP Officejet 5740 using elementary OS Freya

Question: I installed hplip, and then attempted to set up my printer using a variety of methods including the built-in printer app, the HP device manager, the system-config-printer command, and the CUPS web interface.  None of these have been successful, as, without fail, the computer will send a page to be printed, the printer will say it is printing, and then it does not print anything.  The printer will say the job is completed, the computer says the same, and yet there will be no noise coming from the printer, and no page will come out.
Comment: Please try to set up your printer with `hp-setup`... EDIT: doh! you already tried :/
Comment: Remove the printer from system preferences
Try > hp-setup -u
Answer: According to the official HPLIP-Database your printer needs HPLIP version 3.14.10 or newer.
Unfortunately elementary OS supplies HPLIP 3.14.3 by default, which does not support your printer.
You will need to install a newer version of HPLIP (choose Ubuntu 14.04 as distribution).
Please create a backup of your system before installing a third-party Application, just in case something goes wrong.
Comment: Also, one thing worth pointing out: while installing the newer driver, the installation will not recognize that elementary OS is actually built on top of Ubuntu 14.04. The installation will test whether or not you're running Ubuntu 14.04, and once it figures out you're not, you'll have to install every dependency manually (which requires a bit of patience and Googleing).


Correlation Between 2 Portfolios

Question: I have a set of assets, n. I'm trying to find the correlation between 2 portfolios, say x and y, where x is nested in, or, a sub-set of y. That is, x is a portfolio based on a sub-set of n, while y is a portfolio based on the entire set of assets, n. The weights in each portfolio sum to 1, and I'm using Excel. Thanks for your time!
Answer: You will need the covariance matrix to calculate this.
Say you have a collection of $n$ assets. The value of asset $i$ is represented by the random variable $X_i$ and the corresponding portfolio weight is are $w_i$, and $v_i$ for the two portfolios.
The correlation between the two portfolios is:
$$ \frac{\sigma(w^TX,v^TX)}{\sqrt{(w^T\Sigma w)(v^T\Sigma v) }} = \frac{w^T\Sigma(X)v}{\sqrt{(w^T\Sigma w)(v^T\Sigma v) }}$$
Where $\Sigma$ is the covariance matrix.
You can arrive to this conclusion by using variance's bilinear property.
And without using vector notation:
$$ \rho = \frac{\Sigma ^n _i \Sigma ^n _k w_iv_k \sigma(X_i,X_k)}{\sqrt{Var( P_1 )Var(P_2) }} $$
Where $Var( P_1 )$ the variance of portfolio 1.
Also take a look at this related question at math stack exchange.
Answer: If you're in Excel, get the returns of both portfolios into 2 columns, matched up by time.  The "correl()" function will get you the correlation coefficient.

Correlation Between 2 Portfolios


Understanding MSP430 ADC setup

Question: I'll get the first statement out of the way: I am a complete beginner when it comes to programming. I have a decent grasp of an Arduino, and have also been using the STM32 (via the Nucleo) and have become quite accustomed to using them.
Recently, I have decided to look at the MSP430 as these (alongside the STM32) are the main microcontrollers used at my place of work, so I would like to get to grips with the basics.
I was surprised to see just how different they are, for example, even blinking an LED example between the STM32 and MSP430 had a vast difference in how they were written and set up. However, I would like to get to a stage where I can use both microcontrollers eventually.
So far, I am following the same learning curve on the MSP as I have with the others. My plan is to blink and LED, then change the time between blinks, then toggle with a button, then toggle 2 LEDs, etc etc. This all comes from using examples as a starting point and editing it to fit my needs. I have now got to the stage where I want to read an ADC value and light up different LEDs as the ADC value increases. Sounds simple enough. I have found a few examples on using the ADC, but I don't want to just copy and paste and be done with it, and there are a few things I am unclear of in the setting up of the ADC, and I don't want to continue without knowing how to use them, otherwise I am setting myself up to fail in the future, so I wanted to get some clarification on what they mean. The examples I have seen have the following ADC setups:
<code>    void main(void)     {       WDTCTL = WDTPW  + WDTHOLD;    // stop WDT       //
 ADC configuration
         // V+ref=3V,V-ref=0V,Channel=A0

         ADC10CTL0  = ADC10ON + ADC10IE; // Vref Vr+=3v,Vr-=VSS,
                                        // S&Htime = 4 X ADCCLK,ADC10 on,ADC interrupts enabled
         ADC10CTL1  = ADC10DIV_7;        // INCH =0000->A0,ADCCLK src = ADC10CLK,
                                        // ADCCLK/8,Single Channel Single Conversion
         ADC10AE0   = INCH_0;            // channel A0

         ADC10CTL0 |= ENC + ADC10SC;     // Start Conversion
                _BIS_SR(LPM0_bits +GIE);        // Go to LPM0,interrupts enabled    }
</code>
And the second:
<code>void main(void)
{
    WDTCTL = WDTPW + WDTHOLD;                   // Stop watchdog timer
    ADC10CTL1 = INCH_10 + ADC10DIV_3;           // ADC Channel -> 10 (Temp Sensor), CLK/4
    ADC10CTL0 = SREF_1 + ADC10SHT_3 + REFON + ADC10ON + ADC10IE;
                                                // Ref -> 1.5V, 64 CLK S&H, Interrupt Enabled
    __delay_cycles(100);                        // Wait for reference to settle
    while(1)
    {
        ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start
        __bis_SR_register(CPUOFF + GIE);        // LPM0 with interrupts enabled

        adcValue = ADC10MEM;                    // Fetch ADC conversion result

        // C = ( (adcValue/1024)*1500mV)-986mV)*1/3.55mV
        tempC = ((adcValue - 673) * 423) / 1024;

        __no_operation();                       // Required for breakpoint
    }
}
</code>
I am fine with the watchdog timer disable. My main issue is with the ADC setup, and not knowing what each do. In the examples, both ADC10CTL0 and ADC10CTL1 are used, but both setup differently. Looking for ADC10CTL in the datasheet of the MSP430 I am using only tells me what they are (ADC control), not how to set them up, or what parameters to set up in there, so I would like some clarification on that, because the notes don't make sense to me. For the first example, I get that ADC10ON means to enable the ADC, and ADC10IE is the interrupt enable, so why in the notes is the S&H time mentioned? I can't find that in the datasheet? It also mentions the Vref value, which I can't see referenced. In the second example, ADC10CTL0 references REF)N, ADC10SHT, so I am a bit confused how to actually set this up.
The next is the ADC10CTL1 setup. I get the ADC10DIV is to do with the CLK time (although I would like clarification on how this works), but the 2 examples set up the channel used differently. I see that INCH references the input channel, but the second example has this setup in ADC10CTL1, and the first example uses a separate setup with ADC10AE0, which I cannot find a reference to in the datasheet, so I am unsure what this is.
I am happy with the start conversion, but confused on the second examples use of ADC10MEM, which I assume is where the conversion result is stored, yet I cannot find this in the datasheet either? Unless mine uses the ADC10MCTL0? (Page 92)
Any help understanding the setup of the ADC will be very much appreciated, as I don't feel comfortable with moving on untill I am confident I can set it up without having to copy and paste examples constantly.
If any other information is required, please feel free to ask.
Answer: You need to find the User Guide for the MSP430 processor you are using.
It can be found on TI's website under the product page for your MCU.
In chapter 27 of the User Guide the registers are explained in detail.
Comment: @jsolarski I have looked up a few bits of example code, I can easily copy and paste and get it working, but I just wanted to find an explanation of it all, as I would much rather understand what I am doing
Comment: Ahh, thanks for that, I'll have a read through and see if I can get my head around it
Comment: Ahh, I think there is a typo in the datasheet. ADC10MCTL0 is repeated twice in the table, where according to the user guide, it should only be for memory control, the actual memory should have been ADC10MEM. That'll explain why I was unable to find it when searching! That is at least 1 of my question answered!
Comment: also look at the example code from TI, should be near where you found the user guide, it should be your go to for basic setup.

Understanding MSP430 ADC setup


How can i define algebraic equation in differential function in MATLAB?

Question: I want to solve 7 pde's that are functions of time, radius(j) and length(i). I used the method of lines and converted them to a system of odes in time and it becomes something like this:
$$dy/dt=((y(i,j)-y(i,j-1))\Delta{r} )+(y(i,j)-y(i-1,j))\Delta{x}$$
I define all of the equations in one function in MATLAB. This is my function:
$$dy/dt=f(t,y)$$
and then I solve those ode's by using ode15s solver.
Now one of the boundary conditions is an algebraic equation that should be in this function too. It is an algebraic equation of the form: $$y=f(r,x)$$
so I think if equations have the same appearance, I can write all of them in one function. So I write it in this way:
$$(10^{-10})\times dy=y-f(r,x)$$
I put this small coefficient to eliminate $dy$ effect and solve algebraic equation, but MATLAB cant solve it. How can I define this function?
Comment: I don't understand your notation. Are the functions $f(t,y)$ and $f(x,y)$ supposed to be the same? And how does the third equation follow from the first two? Finally, is $dy$ supposed to be some kind of time derivative? Please clarify.
Comment: sorry. ok i explain it now.
first i have 7  equations that are function of time and radius and lenght.
i used method of line and covert PDEs equations to a system odes(dy/dt).
this is one of the differential equations:
dy(i,j)=(Ao*epsilonf.*Ucp*y(i,j))-(kg*Ao.*(y(1,1)-y(2,1)))
and my algebraic equation is this:
y(i,10)=((Deff/deltar)*(y(i,10)-y(i-1,10)))+kg*Ao*(y(2,10)-y(3,10))
so my odes are time derivatives.and (i,j)are notations for r and x.
Comment: Hi Fatemeh. As Wolfgang says your notation and question in general is very confusing. If $dy=dy/dt$ then you should just write dy/dt. Also since the 7 differential equations are easy to write out (given you wrote one in your comment) I think you should just include them. You also multiply by 10^-10 to eliminate dy. How is this justified? In order for someone to answer this question I am afraid it will likely need to be significantly re-worked so that it is comprehensible. As it stands I have no idea what you are trying to do.
Comment: thanks James.7 differential equations are the main equations.but algabreic equation is boundry condition.i dont know how use this algebraic equation with those diffrential equations?
it was my idea that if the Appearance of equations are same i can write it in one function.because a algebraic equation dont have dy/dt term i think its better to use a small coefficient to eliminate its effect.
Comment: @fatemeh, please edit the original question to make your intent clear.
Comment: @  Wolfgang Bangerth, ok. i have done.
Answer: Your question is not quite clear, but if your problem is roughly analogous to
$\frac{d\mathbf{x}}{dt}=\mathbf{f}[\mathbf{x},y]$ , $g[\mathbf{x},y]=0$
then you just need to use a mass matrix in your call to ode15s. This is how you "tell" Matlab that you have an algebraic equation.
That is, in Matlab pseudo-code you can express the above as
eye(n)*dxdt = f(x,y) % n=length(x)
  0   *dydt = g(x,y) % y is a scalar

which you would pass to ode15s as a single system
M*dzdt = h(z) % here z=[x;y] , h=[f;g], and M = blkdiag(eye(n),0)

The particular syntax will depend on the specific system. The relevant part of the help in the above link begins where it says:
"If the mass matrix $M$ is singular, then $M(t,y)y′ = f(t,y)$ is a system of differential algebraic equations."
(Edit: The explanation here may be more clear.)
Comment: Thanks a lot. Yes this is my problem. I read about mas matrix. But its not quite clear. Can you explain how can i define this matrix in MATLAB?
Comment: fatemeh - I gave a simple example of a mass matrix in my answer, and linked to the Matlab help page describing the syntax and options to use in calling ode15s. To be more specific, you would need to define your particular system in the question. That said, perhaps you should post this over at http://www.mathworks.com/matlabcentral/newsreader/


Stoichiometry of alkane-perchlorate reaction

Question:
What are the products of an alkane and a perchlorate reaction?
e.g., making the alkane methane and the perchlorate anhydrous for simplicity:

My effort:
$$\ce{Mg(ClO4)2 + 4CH4 -> MgCl2 + 4CO2}$$
leaves 16H free so obviously incorrect, but shouldn't a salt and a gas be part of the products? I guess that the anhydrous form would make this explosive.
Answer: I think that there is some $\ce{H2O}$ as product:
$$\ce{2Mg(ClO4)2 + 4CH4 -> 2MgCl2 + 4CO2 + 8H2O}%edit$$


Content Manager Explorer does not open context menus

Question: I am using SDL Tridion 2013 SP1. In Content Explorer context menus were not opening (I am trying to install Content Porter but Tools menu is not opening). I am using IE 10 and I have configured IE as explained in here, but still it is not working. Can any one help me to fix this issue. Thanks in Advance.
Answer: Internet Explorer's Compatibility Mode has caused issues for me. Even when not set intentionally, I believe IE's default sets Display intranet sites in Compatibility View, which likely applies for most SDL Tridion setups.
In IE 10 this breaks a few things in the Content Manager Explorer including the Tools tab and Ribbon Toolbar buttons in form view. Try unchecking the option in IE under Tools > Compatibility View Settings then refresh the browser.


Meaning of asozial in German language

Question: I recently heard the word "asozial" is an insult in Germany. As far as I know, in other cultures it is not perceived as an insult in general. How bad is it in meaning in German culture?
Comment: Example of a "false friend" - something that looks similar to a word in another language, but totally different meaning. Sensibel ≠ sensible. Pathetisch ≠ pathetic. And many others.
Comment: Note that being "asozial" was a crime in national socialism (and I think under socialist rule in the GDR), specifically the crime of rubbing national socialists somehow the wrong way. This was enough to get you murdered in a concentration camp. I know that some people use the word very casually (in the sense that they mean exactly the same thing as the Nazis, but would not go out of their way to have them murdered themselves), but I still would suggest you avoid the word.
Comment: @gnasher729: prägnant ≠ pregnant, ich will ≠ I will, bekommen ≠ become
Comment: @HubertSchölnast a German teacher I had at high school loved to tell the apocryphal story of a German tourist requesting to "become a shrimp" in a restaurant abroad...
Comment: preservative ≠ Präservativ :-)
Comment: Also a classic "I have a date with your chef!" (for a job interview)
Answer: The German word »asozial« means in English

anti social = against the needs and rights of the society

People who behave asozial violate basic rights of other people.

A person who plays loud music in the middle of the night, so that other people can't sleep, acts asozial.
A person who smokes cigars when they are in a closed room with little children acts asozial.

But some people use this word also for people who in fact just need help. They call homeless people or long-term unemployed person asozial (»Assi« = short for »Asozialer«) just because they receive financial support from the welfare system, although most of them do not really behave asozial.
Comment: asozial is often used like antisozial. when used in regard to homeless people, it retains it's original meaning: not part of normal society.
Comment: @nmd_07: This has nothing to do with "Germans collectively". Looking down on people who are (perceived to be) different has happened in all societies in all ages since the beginning of humankind, and is even observed in animals. Nothing to do with Germans, Germany, or the German language. Not everybody goes to the extremes that my country went to to eradicate people who are (perceived to be) different, but it is by no means unique to Germany.
Comment: Worth noting: that's not what the actual English word "antisocial" typically means (though I do see it listed in the dictionary). In typical parlance, someone is "antisocial" if they don't want to be social, that is, to spend time with other people, especially if it defeats others' efforts to be social, such as by not participating in a group activity.
Comment: @nmd_07: IMHO drawing the line around "normal" gives a wrong impression of the meaning. There are plenty of types of people who are not a part of "normal" society, but by far not all of them are "asozial".
Comment: I tent to object: "asozial" is strongly negative. It does not mean the person is "not nice", but it means the person lives against what is considered social standards, like lying around drunken every day, smelling strongly due to not washing, using very bad language, etc.
Comment: @Peeja Some people use the term "asocial" for someone who simply shuns social contact, and "anti-social" for someone who is a menace to others. Certainly terms like "anti-social behaviour" do not mean loners who spend all day in their rooms...
Comment: @nmd_07 What one person finds asozial, the next person might find acceptable or maybe even perfectly normal. It is usually used as value judgement, and like all value judgements it is subjective. We germans agree what the word asozial means, we have different opinions on what constitutes asozial behaviour though.
Comment: @Benjamin why is not being part of "normal" society considered as an insult? The definition of "normal" is a really relative concept. Why do Germans collectively think that everyone has to fit in? It doesn't make sense.
Comment: Studying chemistry spoiled me: when I read *Assi*, I pronounce it with /s/ and understand *Assistent*. The short form of *Asozialer* would, to me, be *Asi* and pronounced with /z/. But I am not aware if my usage conforms to spelling norms (if such a norm exists for these abbreviations).
Comment: https://youtu.be/s0VTfB7nAH4?t=32
Comment: This answer is incomplete in a way that makes it wrong.
Answer: The word is composed of two words: "sozial" has about the same meaning as "social" in English and comes from the latin "socius" (comrade, member). Words like "society" also come from "socius".
The prefix "a-" is greek and means "devoid of", "not concerned by", "not having...", etc.. This is a slight difference to "anti-" which means "contrary to". Someone "antisozial" is (actively) acting against societies norms - someone "asozial" is not concerned with societies norms at all.
In day-to-day German use of language the word "asozial" is usually meant as "not concerned with the well-being of ones surroundings", but - as @Hubert Schölnast" pointed out - often with the connotation of "not contributing to societies advancement" for whatever arbitrary reason. It also has the connotation of "inhumane", "inconsiderate", "ruthless", "reckless" or simply "unkind".
I hope this helps.
bakunin
Answer: One thing to note is that the word antisozial may exist but is not very common; asozial covers its meanings as well. German equivalents to English asocial would be ungesellig, einzelgängerisch or eigenbrötlerisch.
With respect to use and history of the word the Wikipedia article is quite elaborate and, as far as I can tell, accurate.
The word asozial has been used under the Nazis and in the GDR to discriminate against and to justify persecution of certain groups of people who were non-conformant. The violated norms could be cultural (hippies, Sinti and Romanies), social (homeless), economic (no steady employment) or psychological (mentally ill). Often several of these deviations from the norm occur together: Most homeless will be unemployed, and mental illnesses among them are common. In most cases there are visual clues like shabby or non-standard clothes and lacking or non-standard haircuts which make a visual categorization easy.
In the way my grandmother and mother used the word, the reverberations of the Nazi use were clearly palpable; asozial was used as a term of abuse against people who were perceived as inferior or debased. A neighborhood with subsidized housing was where the Asozialen lived.
The subtext stemming from the Nazi worldview that was never consciously reflected — or maybe agreed with — was that being asozial was an intrinsic condition that was of course also passed on to the offspring. It is obvious that such a concept leads to specific policies of which putting people in concentration camps is only the most consequent one.
To me the word asozial is quite toxic, in a line with the N-word or calling someone a spastic. I would strongly advise not to use it.
Answer: In a common way most young people use it, it has a meaning of a person who does not have a job and gets financial support from the system like Hubert said. But that is not the only thing. In addition it describes people also as persons that don't really take care of themselves, don't clean their rooms at home and in general do not do very much all the whole day although they have the time for it. You can also use it with an image of a person who consumes a lot of beer and other liquor.
I think it has a different meaning for each person who uses the word asozial, but this should cover the most common meanings.
Comment: So basically "asozial" means to be considered "not belonging to the society", but it's independent of racism.
Answer: To add to the excellent answer by Hubert, asozial is generally quite derogatory and informal, and usually applied to young people; an English comparison that comes to mind is "Chav", or perhaps "Asbo".
Answer: If I had to translate the common meaning of "asozial/assi" as an insult directly, I think "trashy" is a really good fit.

Meaning of asozial in German language


Do vegetable seeds have a shelf life?

Question: I bought vegetable seeds a few years back.  I tried planting them this year but am having mixed results (very few are sprouting).  Do seeds have a shelf life/expiration after which they will not germinate?  I am trying to figure out if the problem is with the seeds or something else.
Comment: Yes indeed they have a shelf life and the GOOD seed companies tell you what that length of time is; 1 year, 2 years, 5 years.  But remember that seed bank in Iceland?  Below freezing temps all year round...they have to continually replace seeds, depending on the seed.  I buy major seed every other year but never throw away any seed because if 8 out of 10 seeds germinate year 1 (85% is a good germination rate), the next year might be 6 or 7 if that seed had been kept cool and vacuum packed.  Depends on the type of seed, different plant's seed last differing years.
Comment: Where did you get your seed from, J.?  I get all mine these last few years from Territorial; non gmo, seed grown in my same state, and they put on their seed packets the length of time the seed will keep it's germination rate before it declines.  ie) Carrots Mignon F1; seed specs-Min. germ. standard:75%.  Usual seed life 3years.  Best directions and info I have found on any seed packet.  Cost was 3.85 for 1 gram. A little more expensive but to KNOW it is non gmo and a seed guarantee and to know it is not already 3 years old is worth the extra.
Comment: I think the linked question is helpful as it discusses storage conditions with apply to basically all veggie seeds, not just lettuce.
Comment: I bought mine from Costco.  All organic and non GMO verified.  It says packed for 2015 so not sure what that means. In any case, I seem to be getting zero germination rate so wondering if seeds expired all of a sudden.  I do store it indoors in the original package and conditions are cool (not in a refrigerator)
Comment: @JStorage " It says packed for 2015 so not sure what that means." It means the same as a "use by" date on food packaging - it was intended to be sown in 2015 (and therefore the seed was probably harvested in 2014). It's not too surprising the germination rate is lower in 2017. After a long storage time, it will also depends on how close to "perfect conditions" for germination you achieved in terms of temperature, moisture, soil pH and texture, planting depth, etc, etc. Fresh seed will tolerate more "abuse" than older seed.
Comment: @JStorage "All organic " - have you ever seen any "inorganic seed" for sale? That's just marketing BS - especially if the "organic" seed was packaged along with a random selection of "organic" bugs and viruses, rather than in a nice sterile environment!
Comment: Is this helpful to you? https://gardening.stackexchange.com/questions/24673/does-keeping-lettuce-seeds-in-an-open-package-affect-their-viability?rq=1.
Comment: That question is specific to lettuce but I am dealing with beets, carrots, etc. not germinating.  Looking for some practical experiences
Comment: @JStorage Ouch.  The words organic and natural have been completely ruined.  The fact your seed said 'non gmo' means you got some good seed.  That label does not have to be listed anymore so the companies that DO list non gmo have a bit more credibility.  They want knowledgeable clients.  If it was grown in 2014 makes total sense but you should still be getting some at least 50% germination.  I store all my seeds indoors, in the dark but not in the frig or freezer.  Not sure if I want to as yet. Keep the info about Territorial Seed from Oregon.  I've been very happy with their seed and plants.
Answer: Yes, all seeds have an average "life span", but the length varies between species and is greatly influenced by storage conditions like temperature, humidity and light.
As a rule of thumb, dry, cool and dark, possibly in the original sealed package is the best way to store seeds.
The standard garden veggie seeds should typically1 last at least two to three years under the aforementioned storage conditions. After that, you'll likely notice a drop in the germination rate, which you can counter by sowing a bit more generously (you can always thin the seedlings later). Consider a germination test for older seeds to get an idea of what you can expect from a particular batch

1 Of course there is some variation. Unfortunately, I don't have a handy table or similar at hand. Check your seed packs for either a production date / year or some other date, e.g. a recommendation to use the seeds until a certain year. Some companies will give a "germination guarantee" until a certain date or similar.
Comment: Wish that was true for weed seeds
Answer: I agree with Stephie, but if you have old seeds, just try. Germination rate should still be above zero. I think 10 years is still significant, e.g. more than 1/3. Considering that often seed packs have too much seeds, it is still an option.
This year I put together a lot of seeds I had (few from '80, but most from 2000 to 2012). It was a real overseeding, in bad conditions (I didn't work too much the soil, because I didn't get much chances). Anyway I get a lot of seedlings from many different kinds.
From my experience (not so scientific): Cucurbitaceae (e.g. zucchini) and Apiaceae (carots) have good germination also after long time. Solanaceae (tomatoes) and Brassicaceae (radish, rucola) follow them.  I had more problem with beans: they dry quickly after few years of bad storage. I didn't have many seeds of Asteraceae (lactuces) and Amaranthaceae (Swiss chards), so I cannot really tell you about that.
Answer: No, or may depend on the seed. When I had a vegetable garden, I had some seeds 15+ years old  . I didn't have a problem with sprouting. I did store them sealed in a refrigerator. At one time I thought 5 year old onion seed was bad, so to use it up I planted it very thick. That was a good weather year and it looked like I had a row grass in the garden. I may have a new data point; planted some 35 year old coral beans a couple days ago and they are  now swelling . I believe sprouting rates are 95 % moisture, temperature, etc.
Answer: Generally speaking, light, heat and moisture degrade their viability/ability to germinate.
With the exception of bean and pea seeds (which form a hardened coating in response to cold), as soon as I'm done using them, I tape the envelope shut, then I put all my seeds that I want to try and reuse in a zip-closure plastic storage baggie (a thicker one, like "storage" or "freezer" variety, not the really thin "sandwich" ones), a pint or quart size is fine.  I add uncooked white rice (to absorb any excess moisture), squeeze out the extra air, seal it and store it in my basement fridge, in the crisper drawer, where it stays in cool dry darkness until the next planting session.
I have no problems with germination rates for at least two more years.  From Giaccomo's answer, looks like this can be pushed quite a bit further.  I generally never try to push it to a fourth.  This works great for peppers, tomatoes, cabbage family (inc. Brussels sprouts, broccoli, and cauliflower as well as cabbage), lettuce, squash/pumpkins..... you name it.

Do vegetable seeds have a shelf life?


Should I adjust historical data for dividends when estimating drift?

Question: I'm building a Geometric Brownian Motion model which incorporates future dividends which vary over time. Since these should reduce stock price when paid, I can incorporate that into the model, however, I just realized that when I estimated drift from historical data, that data already incorporates dividends. Should I adjust the historical to remove the impact of the dividends?
Answer: In a Black-Scholes framework, the Geometric Brownian Motion specifying the dynamics of a stock continuously paying dividends is given by:
$$ dS_t = (\mu_{\text{Total}}-q)S_tdt+\sigma S_tdW_t $$
Under the model above, the stock price $S_t$ is continuously paying a dividend equal to $qS_tdt$, and as a consequence the stock price depreciates continuously at the same rate $-$ the same way in stock markets, stock prices plunge immediately after a dividend payment by an amount equal to the dividend paid.
Let us define $\mu_{\text{Price}} = \mu_{\text{Total}}-q$. Now, depending on what you mean by:

"[...] data already incorporates dividends."

We have:

If your stock data is not adjusted for dividends $-$ "not adjusted" meaning that stock prices do not incorporate paid dividends $-$ then if you estimate the drift on that data series you will be estimating $\mu_{\text{Price}}$ i.e. the price return drift which only captures returns from variations in the stock price independent of dividend payments.
If your stock data is adjusted for dividends $-$ "adjusted" meaning that stock prices are corrected by adding back paid dividends $-$ then if you estimate the drift on that data series you will be estimating $\mu_{\text{Total}}$, i.e. the total return drift which incorporates dividend return.

You can manually adjust your data series to "remove the impact of the dividends" $-$ I am unsure whether you mean subtracting paid dividends from the stock price, or adding them back $-$ and you will be able to estimate both drifts $\mu_{\text{Total}}$ and $\mu_{\text{Price}}$ from each data series, adjusted and unadjusted. From there you can also estimate the continuous dividend yield $q$.
For discrete dividend modelling, things get messier. You can take a look at Wikipedia's article on the Black-Scholes model, where they consider extensions with dividend-paying stocks.


Can you say anything if you see cheating at another board?

Question: Let's say you see that player A on the board next to yours violates a rule such as touch-move or changes the move after releasing the piece, but their opponent, player B, doesn't notice. Can you say anything to player B, and if so, could B make a claim based on third-party testimony for a violation B didn't even see?
Answer: You should not address player B directly, it is forbidden to talk to him about his game (it is actually forbidden to talk to him at all, but the spirit of the law is to prevent conversations about the game).
However, you can (and should) tell the arbiter about what you have seen, and the arbiter will decide on the appropriate action.
Comment: Would the arbiter notice himself cheating, he would intervene without needing the opponent's request. In the case he has no other information that what you told him, his reaction might depend on a lot of other factors, but at the least he'll be very careful about A's behavior afterwards.
Comment: @itub That sounds like it deserves its own question.
Comment: Good point about not talking to B. But could/should the arbiter do anything without the interested player (B) making a claim?


iMac 3GHz w NVIDIA 9400 -- Unable to install generic nvidia drivers

Question: I can't install the latest NVIDIA drivers for the 9400 on this iMac (Early 2010 Model, 20.5" Screen).
I'm running Windows 7 64bit, and I tried installing both the 9400M and 9400 drivers.  The actual NVIDIA lookup utility on the site says it's a 9400, but the apple documentation says its an M model.. Regardless, neither one will find the hardware.
I'm just trying to run CIV5, but it's performing absolutely horrible.  It ran pretty terrible with the stock Windows 7 64bit drivers on another PC I have, so I know I definitely need better drivers for this machine to run it smoother.  Anyone ever deal with this sort of thing before?  I've used tens of NVIDIA cards before and never had a problem like this.
Oh, and Apple has no driver updates from what I can see.
Answer: I believe the nVidia chips in the iMac are the Mobile variants. Grab the drivers from Laptop Video 2 Go and install 'em


Consumer behaviour

Question: If the last dollar spent on commodity X gives him less marginal utility, he will withdraw this amount from X and spend it on Y if it gives him higher marginal utility. Here consumer how can consumer withdraw amount from x and spend it on y?
Answer: I think the problem is with the tenses. All the analysis is made before actual transactions take place. We are evaluating an hypothetical situation: A consumer considering buying a bundle $a=(x_1,y_1)$ realizes that if she did, the marginal utility of the last dollar spent on $x$ would be lower than that of the last dollar spent on $y.$ We observe that switching expenditure from $X$ to $Y$ would result in larger total utility. And since we expect consumers to maximize their utility, they will do so. This results in the consumer withdrawing part from the expenditure in $X$ and spending on $Y$ with respect to the hypothetical bundle $a$

Consumer behaviour


Limit download speed

Question: I searched on the net on how to limit download speed but I only find some software. Is possible to limit the download speed in Windows XP by configuring some settings on the computer? How I will limit the download speed ? I only want to limit the download speed not the internet speed.
Comment: What is the difference between download speed and internet speed
Comment: download speed is for downloading a file while internet speed is for browsing the internet
Answer: It is probably not possible to do this well.  Generally you can only limit speed leaving an interface.  There are hacks which deliberately drop packets to cause TCP sessions to retransmit slower which works (in theory) with TCP, but its quite crude and inaccurate.  Realistically though, this is something that should be done on a router, as a router always has an interface where packets leave the interface (where the packets are not dropped).
You might want to advise what protocol you are using, as some software has rate limiting built into it, which can be useful if you have multiple simultaneous connections  (simultaneous connections will sometimes defeat dropping packets to get TCP connections to go slower, but you can limit the number of connections in, for example, P2P clients).
Answer: After reading the question I can say the following: for Windows XP (or any OS, by that matter), it is impossible to do that.
Why? OS don't distinguish between what you call Internet and what you call download because, essentially, they are one and the same. In order for you to use the Internet what you are doing is downloading the resources provided in the address you typed in order to see them.
However, if you were to change settings inside a browser, that would be doable. Assuming you used Firefox, there is an addon called DownThemAll!. It is a quite versatile download manager and accelerator. One of it's features is a limit on download speed. Never used it myself, but it should work.
Why does this work? Because browsers understand your concepts of Internet and download.

This picture was taken from the Screenshots portion of the site I referred before. The Download Limit dropbox is located on the lower right corner, next to Preferences.

Limit download speed


I'm looking for a fiction book about pyramids

Question: I read this book a very long time ago (30+ years.) All I remember for sure is Giza and Cheops pyramids were important points, they emitted some sort of energy.  The end of the book was calamitous.  The world as it was at the time was destroyed, the pyramids survived and two humans were created, named Adam and Eve.
If I remember correctly, a husband and wife team wrote the book.
Comment: Welcome to SFF:SE. I suggest you have a look at our [guide](https://scifi.stackexchange.com/tags/story-identification/info) to story id questions to possibly jog your memory for more details.
Answer: This is Siva! by Leigh & Walt Richmond.

From my memory of it, the pyramids were slowly building up a power charge.
This power supported a high tech civilisation with flying cars known as carapets (flying carpets, geddit!) and they were launching space craft to explore the solar system when it all went wrong and the ionosphere exploded.
Earthquakes and a big flood ensued and some people in a Space Ark guided the primitive descendants for a long time.
At one point they took two abandoned youngsters on board (Their names were Adam and Eve) and educated them in a greenhouse hold (garden) on which plants were safe to eat.
Eve got pregnant and the attendants joked about her swallowing an apple seed. The two were eventually sent back to the planet's stormy surface.
From Fantastic Fiction:

A science Fiction novel of the far past. In 1962 Walt Richmond developed his theory of the Solar tap. It makes a lot of anomalies of the past fall into place. He has written an Esssef book about it and you as reader may decide whether the story approaches the actual beginning of our civilization...

From Goodreads:

The Great Pyramid of Cheops: Geometrical perfection.
The Piri Reis maps: ancient cartographs that show Earth as seen from polar orbit - they have recently been confirmed by satellite photography.
Myriad proofs that Earth has changed its axial tilt during near-historical times: perhaps as recently as 1450 B.C.
In 1962 Walt Richmond developed the theory of the "solar tap": a source of electrical power so great that one installation could provide the world's power. In 1963 his research papers were labeled "Top Secret." The Richmonds refused to work under conditions of secrecy, but Walt worked out on his own the ideal structure for a solar tap.
The Result: an exact replica of the Great Pyramid.
The kind of power postulated by the Richmonds' findings makes all the anomalies of history fall into place. This book was written as science fiction. Whether the story approaches the actual beginning of our civilization is something for each reader to decide for himself...

There is an extensive review of the book under its original title, The Lost Millennium, here.

It has been suggested as an answer for another question here.
Comment: @danny3414 No problem.  I was intrigued, so was looking things up for myself & had the links.
Comment: Thanks for good editing of my answer - much appreciated @eshier
Comment: Thanks for your next to last line. I knew I had read this but not under the name of "Siva".


Visiting mainland China via Hong Kong and Macau on a single-entry visa

Question: I am a Indian Citizen and am going to Shanghai (China) via Macau and I am going to Macau through Hong Kong via ferry, then from Macau I will visit Shanghai (China). Is this possible with a  single-entry visa for China?
Comment: If your itinerary is HK->Macau->Shanghai you only enter the Mainland once, so a single entry visa is okay. I'm not sure that's your question though.
Comment: My itinerary is same as you mentioned .Please  confirm that if i go macau via hongkong through ferry then will i enter into main land of china?i.e. will it we considered as single entry in china
Answer: Based on your itinerary home->HK->Macau->Shanghai->home
Your China visa is only needed when you enter the mainland, which does not include Macau or Hong Kong. Although they are both officially part of "China" they are treated almost as separate countries for immigration and customs purposes. The border is called a "boundary" but you will find immigration and customs people there.
So when you land in HK you will be subject to HK immigration law, and will get a stamp in your passport (assuming you don't take one of the ferries that leaves without going through immigration in HK), then you will exit HK (surrendering your departure card) and go through Macau immmigration- another entry card, and another stamp. Then when you leave Macau and enter China, presumably at Zhuhai, you will exit again and only now will your China visa will come into play.
So, in short, your single entry China visa is fine for this itinerary.


Are providing link to "find my mistake" question of the solution okay?

Question: The title might not describe my question really. I want to ask that there are several questions like what have I done wrong or what is my mistake. I usually answer these question telling them their mistake but in some of those question I additionally give them the link for an alternative solution for a exactly same question usually of website "toppr" etc. So is this desirable behavior? Or should I change my behavior and instead post the solution using MathJax? I usually don't do so because the main question is about identification of mistake and not about alternative solution but to give them some help I do so. So should I change this behaviour or is it fine? Or should I stop posting alternative solutions only?
Comment: I think doing that is fine (so long as the post is not a PSQ.)  It's helps the OP frame their question from "what did I do wrong", given a link, so they can focus on what is a good approach, allowing them to learn "what can I do that is correct."  Too often students (and some instructors) are focused on anything that is wrong, so it's a nice opportunity, in what you describe, to both answer their question, and offer successful alternatives.
Answer: There is nothing wrong with that approach (as long as the question is acceptable, of course). As long is your answer contains the explanation about where the error is, it is fine to add links to external sites with information which the OP may find relevant to the question.


Why do non-mining nodes listen to transactions?

Question: I still don't understand why full but non-mining nodes listen to transactions. The validity of the transactions are ensured cryptographically. So what advantage does it give to either me or to the network? What am I supposed to do with that info when I get a live transaction? In my understanding, a full node should only listen to new blocks, unless it is also mining at the same time.
Comment: who will relay transactions to mining nodes?
Answer: There are multiple reasons.

Wallets Maybe the node operator also has a wallet, and is interested in seeing unconfirmed transactions that pay him. It's generally discouraged to have a business depend on irreversible actions taken based on unconfirmed transactions, but this is not true for everything. You could for example start preparing a shipping order as soon as an unconfirmed payment comes in, but verify that the transaction is confirmed before it actually goes out the door.
For fee estimation Maintaining a set of unconfirmed transactions in a way that lets you predict what will be confirmed in the near future (specifically, by running the same code as miners do) gives you insight in how fast network transactions with certain properties get confirmed. You cannot base this information purely on what you see in blocks, as that can be trivially gamed by miners (e.g. by stuffing their own blocks with a number of very high fee transactions).
For network propagation Modern block relay solutions (like BIP152 Compact Blocks, FBRP, FIBRE, thin blocks, ...) rely on the fact that most transactions in a block can already be known to the receiver ahead of time, if they maintain a pool of unconfirmed transactions. These protocols massively reduce the time needed to get a block relayed across the network.

Bitcoin Core since version v0.12.0 supports the <code>-blocksonly</code> flag, which disables all downloading and relay of transactions. It comes with a bandwidth reduction, but also loses the benefits listed above.
Comment: Listening to transactions means that nodes aren't basing their estimations purely on the transactions that are in blocks. For example, in Bitcoin Core, fee estimation is partially done by seeing how long it takes for a transaction with a certain fee rate to be confirmed. Without listening to transactions, this calculation would be impossible. Even if some miners were stuffing blocks with high fee transactions, using this calculation involving unconfirmed transactions in order to get an estimate that is less effected by the miners.
Comment: 1. makes sense of course but if I am only interested in txs included in blocks it is meaningless to listen and broadcast. Let us say I am an evil and I don't want to spend 1KB of bandwith. 2. I am not sure I understand it. There is a formula that tells the priority of the transactions that the community agrees on. So why am I going to try to read the brain of Mr. Miner? That doesn't make sense. The relation between ordinary users and miners etc have to be analyzed from a game theory point of view, but I cannot  find a rigorous study. 3. makes sense thanks.
Comment: I think the whole point is this: If ordinary users do not listen and re-broadcast txs, then ordinary users cannot broadcast their own txs. In that case the network doesn't work. But let us say I am evil, and I broadcast only my own txs. What effect would such users have on the network?
Comment: 1) You can run Bitcoin Core with the -blocksonly flag if you're really only interested in full blocks, but you'll also loose the benefit of 3. 2) Fee estimation is not that hard in a rational setting, as you can assume every miner will take the most profitable action, which can be very closely approximated by sorting by descending feerate, and pick the top 1M worth of transactions.
Comment: If a very large number of nodes on the network would stop relaying transactions, things could certainly break. If that were to happen, a response could be the creation of specially curated networks you can sign up for, or that people submit their transactions directly to miners, or algorithms that attempt preferential peering between nodes that do relay.
Comment: "as that can be trivially gamed by miners" - listening to txs prevents this in what way? An evil miner can do the same thing by broadcasting its own very high fee txs, for a certain period at least, to manipulate people to believe that they should increase the fees. Sorry, this works only if the miner has a lot of hash power, otherwise he will be paying fees to other miners.


Whole wheat pasta from milling to the results

Question: Can it work to make pasta from freshly home-milled flour?
Answer: Yes. I will show you. Here are my experiment results.

I have this as my mill. It takes a long time to go from wheat to flour and I mean like hours maybe even days.

I tried a 2 3/4 cup flour: 6 eggs: 5 tsp oil ratio and kneaded both batches for a good 10 minutes and rested 1 overnight and 1 for 30 minutes.

I obviously got more than what is shown but I can't show a full 20 ounces with each strand separate.

those black lines are supposed to be the pasta, the dark orange representing that it is whole wheat pasta. The brighter orange is the cheddar cheese sauce. I made this by taking some sharp and some mild cheddar that I have made myself and melting it on low bit by bit so that instead of a crust I would get a smooth sauce. It turned out good and after about 5-6 minutes, maybe less, maybe more, it was al dente and it didn't turn out to eggy or flourly or oily. I think I have found the right ratio for my whole wheat pasta.
Comment: I'm not certain the pictures add anything here.
Also they are not so great.
If you must use paint to make diagrams at least use the text tool for the text.
Better yet do diagrams in something that supports decent shapes etc, like inkscape.
Comment: caters, I think your answer is mostly fine. If you actually did all this work, posting an answer about it is exactly what we want. I won't undelete it for you - that's your decision - but don't let one user who doesn't like MSPaint stop you from posting. I do agree that the images might not add all that much, since you pretty much explained it all in the text, but it's up to you whether you want to include them. If you do, I might suggest trimming the extra white space off the sides so they don't take up so much space.
Comment: You're milling grain with a bicycle? Awesome!
Answer: Of course you can make pasta from freshly milled flour but depending on your grain mill the results might not be what you expect. Some grain mills like the KitchenAid will only grind as fine as corn meal and wheat bran that size could result in a very grainy pasta and might not work well for things like angel hair.
If you've already got a grain mill then go for it! You have nothing to lose and everything to gain by giving it a shot, just be sure to grind as fine as possible. If you're shopping for a grain mill ask the manufacturer if it will grind as fine as pastry flour or Italian Type 00.


Does MO have a stand on neurodiversity?

Question: Does MO have a stand on neurodiversity, if even informal? If not, should it have a stand? And practically speaking, how might it have a stand that could improve the community as a whole?
Comment: Daniel, with your last comment, I have no idea what you are talking about. Delete account? Pronoun war? Better than? Speaking as a parent with a neurodiverse child, I think you are jumping to conclusions (I put "neurotypical" in quotes because I'm not sure what that term even means, especially for mathematicians.)
Comment: No, no stand. What do you have in mind? Most of the time we have no way of knowing who is "neurotypical" and who is not, and pretty much the only guideline in how we treat each another personally comes down to some variation of "be nice".
Comment: Does MO have "a stand" on anything? It provides a collection of questions and answers, a question could be "how to address the needs of neurodiverse students of mathematics", and an answer could be found, for example, [here](https://repository.lboro.ac.uk/articles/The_neurodiverse_mathematics_student/9372383).
Comment: @DanielGeisler I just looked at your comments below Gerhard's answer, particularly the second. If there are specific features that you want that have to do with web accessibility issues for those on the autistic spectrum, then you should make that clear. But I wish, instead of getting upset, you would engage. I had asked: what do you have in mind? I'm not picking up on what it is you want with your question.
Comment: Feel free to delete my account if you don't like my question. I figured out what the collective answer is. If you think you are better than, stand over and stand apart from the causes of out time the "pronoun" war indicates you aren't.
Comment: Sorry, the down votes are all I need to see. Best wishes to folks.
Comment: I have deleted my profile.
Comment: I have voted to close this question. Thank you to the people who reached out to me. I don't belong here. I wish I was capable of being a gentleman, but I'm not. My issues with MO and the math profession are too deep to fix. I just wanted to know if even a conversation was possible without unleashing a down vote hell. I recommend autistic people not use MO or go into math.
Comment: I think that how ended this post was sad, and from this thought (I didn't know/met to the OP) with all respect I would like to add a message with the intention that if the OP reads it in the future, that this person reconsider being a user of this site MathOverflow again. If my comment isn't suitable in this thread of comments, feel free to remove it.
Answer: As mentioned, the forum itself does not have a stand, as it is a database. Also, on many issues, the community is quite divided.  On the basic issue of neurodiversity, I suspect many members have not considered it in the context of MathOverflow.
On the issue of behaviour, matters are quite different.  While "be nice" covers some ground, more subtle issues are at work. In particular, the behaviour of many high reputation users (JDH, David Speyer, J. O'Rourke, T. Tao, R. Bryant, to name a few) are examples to be modeled, and the balance between personal expression and quality content for the forum should always be considered.  If you weight heavily toward the former, the community will not support you.  As a rule of thumb, pretend you are at a seminar with the whole world watching.
(For personal reasons, I do not hold myself to the same standard as the esteemed list above. I am always conscious of the public nature of my contributions though, and try to provide a certain kind of nonprofessional quality, as I want to make some mathematics more accessible.)
It appears to me that you are upset.  I don't know that I can offer any help, but you may find my email address on my user page. Write to me or to the moderators if you have an issue behind the one in this post that you believe merits discussion.
Gerhard "We're Here To Help Many" Paseman, 2020.01.26.
Comment: You are in charge of your own interpretation. Mine is that the question is not worded well enough to admit a useful answer, that people object more to the generality than to the issue.  In short, this is not a good question for MathOverflow Meta.  Gerhard "Might Be Good Somewhere Else" Paseman, 2020.01.26.
Comment: Thank you for your reply. I purposely asked my question in a neutral manner. I certainly would have understood if the reply had been "how could MO support neurodiversity when we don't know the particulars of our members." So I take the seven down votes and the move to close this question a strong support against neurodiversity.
Comment: https://www.boia.org/blog/how-web-accessibility-affects-people-with-autism

Does MO have a stand on neurodiversity?


Use of ADC with Sharp Infrared Sensor

Question: I have a Sharp GP2D12 and I've been using it with my Arduino just fine. I have however had some experience in the past where this sensor (which is analog) was fed into an ADC (like ADC0831) to go to a Basic Stamp. I was wondering what the purpose of this is given that both the Arduino and the Basic Stamp support analog inputs if I am not mistaken, thus it seems weird having an extra and necessary link in the chain. Does the ADC provide more resolution? What is the point of it in this circumstance?
Answer: The Basic stamp does not have an analog input. It has a method that can be used to attempt to measure voltage, but the output won't be as good as a proper ADC.
Briefly, the Basic Stamp uses an internal RC circuit and a timer to "count" how long it takes to charge the pin, then converts that time constant to a voltage. Here is an application note that describes the process in greater detail.
The method is prone to errors with noise and temperature drift, and also appears to be poor at handling slow changes in input voltage.
So, the point of the ADC is to get a stable reading of the Sharp sensor's output. The Arduino does have an analog input pin, the Basic Stamp does not.

Use of ADC with Sharp Infrared Sensor


High revving when I push in the clutch

Question: So my 05 impreza outback sport is having a high revving issue. It mostly does it when it's been warmed up and it's been getting worse.in between shifting and when I just push in the clutch, I'm at a loss here so if anyone can help that'd be great.
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Answer: It'd help if you described the situation a bit more extensively.
What exactly happens and under which circumstances?
If you don't let go off the accelerator at all during shifting, then it's obvious that the engine will start to rev. Some ECU's are programmed so that it's best to completely relieve the accelerator, then clutch and shift, and then apply the accelerator again. The accelerator input is filtered that way. VAG cars are notorious for this, many people find it annoying to drive. I don't know how Subaru does this.
If the engine revs higher than normally when you have released the clutch again and applied the gas, then it may mean the clutch is worn. You have to describe your problem better for us to give a good answer.

High revving when I push in the clutch


How can I protect myself from revenge attacks?

Question: I'm new to Clash of Clans. I attacked a village today and I did some pretty good damage. I am happy about it-- for now. I know about revenge, and I see it coming. How do I protect myself from the revenge? I could buy shields, but those are really expensive. Any alternate options?
Comment: Don't attack...
Answer: To be clear, there's an important distinction in Clash of Clans when it comes to the amount of damage done in an attack. Resources (gold, elixir, dark elixir) are easily the most limiting aspect in the game. The most painful attacks are typically those that steal a high amount of resources. Attacks that deal a high percentage of total base damage but actually steal very little resources are typically the best possible result you could hope for as a defending player. You get a 12 or 16 hour shield, and at a very low cost to you.
Having your walls, towers, barracks, army camps, etc destroyed doesn't really cost you anything expect maybe a few trophies (and trophies are very easy to earn). So, if you're worried about attacks that destroy 70% of your base, it's not actually a big deal as long as they also don't also steal a large amount of resources that disrupts your base/troop upgrade plans.
Assuming that you can't spend all of the hours in a day every day actively playing (the game forces you off-line at some point anyway), there are a few tips you can keep in mind. The three best ways to deter revenge attacks are also the three best ways to deter costly attacks in general:

Upgrade your defenses

If your village is well defended, it will require attackers to expend a higher amount of resources in order to achieve whatever result they are hoping for (stealing resources, earning trophies, etc). The higher the cost, the more discouraged potential attackers will be to launch a dedicated raid. And don't neglect upgrading walls, either. Walls are very expensive to upgrade, especially at higher town hall levels, but are also very effective in slowing down attacks you'll typically see.

Don't keep more resources stored than you have to

Holding onto a large amount of resources entices players, particularly players that have progressed further than you have, to dedicate a full attack on your base in order to steal the resources you're storing. Have a general upgrade plan in mind, and then try to ensure that you have the minimal amount of resources at any given time to meet that plan. If you earn more resources than you can reasonably use in the near future, then you're simply collecting resources so other players can steal it.

Fine tune your village layout

There are plenty of online resources that provide base layouts. Base layouts should be designed to prioritize the defense of resource storage buildings (including your Town Hall, which now stores a good percentage of your overall resources), limiting as much as possible the amount of resources attackers steal.
Answer: Note: updates to Clash of Clans has rendered most of this answer out of date. Town Halls are storage buildings now and no longer grant a shield when sniped, so they should be housed within base defenses. Spells can no longer damage gold, elixir, and dark elixir storages.
Having a shield and being online are the only two ways to stop someone for revenging you.
You can improve your chances of getting a shield by placing your town hall(TH) in a corner of your village. Some people will just snipe your TH and leave, effectively giving you a free shield.
I find I don't often get revenged unless I do something that a player might consider 'offensive'. E.g. Using lightning spells on their storage to take dark elixir. You will learn of this later.
Try not to hold on to too much resource if it's not necessary. Having a large amount of resource to steal will give more of an incentive for people to revenge.
Comment: This answer is out of date. Town Halls are now treated as resource storages, and are significant ones at that since they store a solid percentage of your overall gold, elixir AND dark elixir. Having your Town Hall destroyed no longer grants a shield, so there is absolutely zero incentive to leave the Town Hall outside of your base. Also, gold, elixir, and dark elixir storage buildings are now immune to damaging spells.
Answer: For a quick safe way is, Try to use most of the resources you have and get strong defending troop from clan castle. Since buying shield is expensive it's not worth. Also as per recent update getting attacked town hall only will not give shield. And being online for more time is also not possible.


Does iron(VI) fluoride exist?

Question: Why does $\ce{FeF6}$ not exist? There are hexavalent iron compounds, so that is not the problem. There is the $\ce{[Fe(CN)6]^3-}$ ion, so there doesn't seem to be a steric problem.
Comment: No, it doesn't, as far as it is possible to prove a negative. Nor do CrF6, MnF7 or CoF5. And note your steric argument is not correct, Fe3+ is appreciably bigger than Fe6+, as far as those terms have any meaning in chemical environments.
Comment: Not an answer. But $\ce{FeF3}$ as a crystal *already is* something like $\ce{FeF6}$, in the sense that each iron is bound to six fluorine atoms; the lattice is linked via $\ce{-F-}$ bridges. The existence of $\ce{[Fe(CN)6]^3-}$ is more of an argument for $\ce{[FeF6]^3-}$ than $\ce{FeF6}$.
Comment: Maybe reading about bonding characteristics of [Potassium Ferrate](https://en.m.wikipedia.org/wiki/Potassium_ferrate) may help.
Comment: Food for thought: The dimer of iron(III) fluoride doesn't exist(unlike [iron(III) chloride](https://www.sciencedirect.com/science/article/abs/pii/S0166128099004029)), but the anion, $\ce{[Fe2F6]^-}$ does exist consisting of $\ce{Fe^2+}$ and $\ce{Fe^3+}$ ions and it form salts like [$\ce{[NH4]Fe2F6}$](https://materials.springer.com/isp/crystallographic/docs/sd_1830851).
Answer: Besides steric factors related to the small size of the transition metal core, we could be seeing an electronic effect described in this answer.  Iron is fairly early in the transition metal series, so when pushed beyond the $+3$ oxidation state it has few $d$ electrons in the central core.  As explained in the referenced answer, this makes the iron strongly pi-electron accepting, and therefore more favorable for combining with a stronger pi-donor ligand such as oxide instead of fluoride.
Comment: Thank you!  So: what about FeO2F2  or FeOF4..?
Comment: You may want to look at https://en.wikipedia.org/wiki/High-valent_iron.  Organic compounds do allow a wider variety of ligands, but all the examples given there (with iron in oxidation states of +4 to +6) still involve pi-donor ligands from Groups 15 and 16, primarily oxygen and nitrogen.
Comment: @ThomasForster Not exactly FeO2F2 but there are similar types of compounds: [$\ce{Fe3(OF)2}$](https://www.osti.gov/dataexplorer/biblio/dataset/1672834), [$\ce{Li2Fe4OF8}$](https://www.osti.gov/dataexplorer/biblio/dataset/1308370), [$\ce{FeSbO2F2}$](https://pubs.acs.org/doi/pdf/10.1021/acs.inorgchem.7b00301?src=recsys).
Comment: @nilay good finds, but no Fe(VI).  They are just Fe(II) and Fe(III).
Comment: This shows that iron can't achieve +6 o.s. that easily.

Does iron(VI) fluoride exist?


How to retrieve data from vault android app

Question: I am using vault android app for hiding my secret data. Unfortunately i have moved every things in Internal memory to External SD card. Now I am able to see my secret documents,photos and videos while opening the vault application. I am able to locate the folder SystemAndroid but i don't know what to do for retrieve my data.please help
Comment: Welcome to Android Enthusiasts! This happens to be a question frequently asked on our site. Have you tried our on-site search? See [How do I search?](http://android.stackexchange.com/help/searching) for help using it. Quick starters: [retrieve vault](https://android.stackexchange.com/search?q=retrieve+vault) / [restore vault](https://android.stackexchange.com/search?q=restore+vault). Please check if any of those (5+8 links altogether) solve your issue, then let us know the outcome. Thanks, and good luck!
Answer: go to Systemandroid  then MXGKJHzyoi== like folder then .image contains photos and .video contains videos. Hexedit any file from .image folder and find data starting from FFD8 AND FFD9 IS end . and save as jpeg. you can see all images.
Comment: Can you format this better? It's hard to follow what you're saying.


How do I increase the bond level for buddies?

Question: In Metal Gear Solid 5: The Phantom Pain, you unlock items and accessories via a bond level. Is there a way to increase the bond level? Will it affect other things (it would make sense)?
Comment: Please elaborate on what you mean by "other things".
Answer: It is indeed possible to increase the bond level with your buddies.
For example: D-horse, take it on missions and ride with it.
Actively utilizing your buddy will increase the bond level.
In the end it comes down to which buddies you want to increase the bond level on. Decide which ones and bring them on the missions with you.

In the upper right corner you can see "Diamond Dogs"-icons. These indicate the bond level you have with this particular buddy.
TL;DR : Yes. Bring them on missions with you.
Comment: @PhilD. I've seen no sign of this. And that's after paying attention to this for a couple hours of playing the game.
Comment: Have you noticed the bond level decreasing when you neglect buddies for a while?
Comment: It can go down though, if e.g. you run over D-Dog with a jeep.
Comment: Yes, abusing the D-Dog will ruin your bond level with him. I accidentally threw a magazine at his nose when he walked in front of me while trying to lure a guard, and his bond level decreased. Not sure if petting him has any effect. I am also curious if, for example, the D-Horse gains bond faster if you don't whip him as much (using the speed up function)
Comment: @LucasLeblanc I have whipped D-Horse a lot from the beginning and the bond increased quite fast. I still whip it all the time and it never decreases, I think it's a normal function.


Humanoid balancing

Question: I'm currently working on Humanoid robot. I've solved the Forward & Inverse Kinematic relations of the robot, and they turn out to be fine. Now I want to move onto Walking. I've seen tons of algorithms & research papers but none of them make the idea clear. I understand the concept of ZMP & what the method tries to do, but I simply can't get my head around all the details that are required to implement it in a real robot. Do I have to plan my gait & generate the trajectories beforehand, solve the joint angles, store them somewhere & feed it to the motors in real-time? or Do I generate everything at run-time(a bad Idea IMO)? Is there a step-by-step procedure that I can follow to get the job done? or Do I have to crawl all my way through those Research papers, which never make sense(at least for me).
Comment: Can you please clarify your question? I'm not sure what it is exactly that you're asking for help with. (Please update the question with more detail rather than replying to this comment)
Comment: I've tried to improve the question. Do have a look
Answer: Keep in mind that the ZMP is a simplification. In practice with walking robots the support polygon is constantly changing so it can be tough to keep the ZMP inside.
Pregenerated (offline) trajectories will only work in very specific conditions (flat ground, no disturbances), and only if you can model your support polygon well.
That said, everything you learn as you try to make your robot walk with offline trajectories will be useful going forward.
Answer: They are two main approachs for humanoid robot walking. Practically it depends on the physical capabilities of your robot and what you want to achieve.
If your robot is able to sustain strong impact and you aim at cyclic walking on uneven terrain  I would recommend to try the Hybrid Zero Dynamics approach. The current best example is the Cassie or the Digit robot from Agility Robotics see [1] for a recent example.
For a more fragile robot, the usual step to make a humanoid walking on flat ground without obstacle is to:

Plan foot steps.
Generate a ZMP trajectory from the foot steps, and the foot trajectories (usually polynomials with zero speed, zero acceleration at the beginning/end and an intermediate vertical point).
Generate the CoM trajectory from the ZMP trajectory.
Use your IK solver to follow the CoM trajectory and the foot trajectories. An inverse dynamic solver would be better, but it is more difficult to achieve.

Once you have a first version of this working in simulation you can try to develop a stabilizer. It assumes usually an estimator of your robot's root attitude (often the waist), and a feedback on the Divergent Component of Motion of your robot. For a good overview on this topic I would recommend the following paper [2].
From this, they are then various approachs depending on what you want to do: multiple contacts, uneven terrain, manipulation, co-working with a human.
[1] Inverse Dynamics Control of Compliant Hybrid Zero Dynamic Walking, Jenna Reher and Aaron D. Ames, ICRA 2021, https://arxiv.org/pdf/2010.09047.pdf
[2] Stair Climbing Stabilization of the HRP-4 Humanoid Robot using Whole-body Admittance Control, Caron et al, ICRA 2018, https://arxiv.org/abs/1809.07073

Humanoid balancing


how to pass an object to the GET handler with Post-Redirect-Get with Spring MVC?

Question: I'm new to Spring MVC and trying to get a Post/Redirect/Get pattern working. We're trying to implement a survey where each page can display a variable number of questions. The way I'd like to implement this is a GET handler that prepares the next survey page and then hands that off to the view. In the same Controller, have a Post handler that processes the form's answers to the survey questions, submits that to the survey service, which returns the next page of questions, and then redirects that next surveyPage to the getNextPage GET handler.
Most of it is working, except the problem is that I don't know how to hand that 'next survey page' object from the POST handler to the getNextPage GET handler in the redirect. The redirect is working; it goes from the POST method to the GET method, but the surveyPage ModelAttribute is a new object in the GET method, and not the one that was set at the end of the POST method. As you can see, I've tried using ModelAttribute, but it doesn't work. I also tried using @SessionAttributes above the class, but then got a HttpSessionRequiredException.
We didn't know how to handle the dynamic form containing a variable # of questions with Spring MVC Forms, so we just did straight JSTL. It's funky but it works. That funkiness is what resulted in using the @RequestBody and SurveyPageBean coming back with the Post. Honestly, I don't know how the SurveyPageBean is populated. It looks like some Spring MVC magic, but it's working so I'm leaving it alone for now (another developer did this and then I picked it up, and we're both new to Spring MVC). Please don't get distracted by the unusual form handling, unless that is part of the problem with the empty surveyPage ModelAttribute not being redirected.
Here's the Controller snippet:
@Controller
@RequestMapping("/surveyPage")
public class SurveyPageController{

    @RequestMapping(method=RequestMethod.GET)
    public String getNextPage(@ModelAttribute("surveyPage") SurveyPage surveyPage, Model model) {
        if(surveyPage.getPageId() == null) {
            // call to surveyService (defined elsewhere) to start Survey and get first page
            surveyPage = surveyService.startSurvey("New Survey");
        }
        model.addAttribute("surveyPage", surveyPage);
        return "surveyPage";
    }

    @RequestMapping(method=RequestMethod.POST)
    public String processSubmit(@RequestBody String body, SurveyPageBean submitQuestionBean, Model model, @ModelAttribute("surveyPage") SurveyPage surveyPage) {
        // process form results, package them up and send to service, which
        // returns the next page, if any
        surveyPage = surveyService.submitPage(SurveyPageWithAnswers);
        if (results.getPageId() == null) {
            // The survey is done
            surveyPage  = surveyService.quitSurvey(surveyId);
            return "redirect:done";
        }
        model.addAttribute("surveyPage ", surveyPage );

        return "redirect:surveyPage";
    }

Answer: Use Flash Attributes as shown in Warlock's Thoughts.
@RequestMapping(method = RequestMethod.POST)
public String handleFormSubmission(..., final RedirectAttributes redirectAttrs) {
    ...
    redirectAttrs.addFlashAttribute("AttributeName", value);
    return "redirect:to_some_url_handled_by_BController";
}

Answer: Your GET takes the surveyPage as a model attribute, which means it is reading it from the URL.  In the POST, rather than adding the surveyPage to the model (which is lost because you are telling the client to redirect, which creates a new request and therefore a new model) you should add the surveyPage as a query parameter in your "redirect:surveyPage"  You'll have to look at how the surveyPage is constructed from the query params in order to know what to put on the query string.
If, for instance, the surveyPage is constructed from a user, page number, and question count or something, I believe you could do something like "redirect:surveyPage?userId=1234&pageNumber=5678&questionCount=12 in order to pass that model attribute along.
Comment: I was planning to do this approach and one of the parameter i'm gonna us it to fetch some data from the DB but my thought is what if that parameter is changed by the user then the data that it supposed to be fetch is change is there another way around?
Comment: If you don't mind using a session you could look at the Flash scope.  http://www.javabeat.net/flash-attributes-in-spring-mvc-3-1/


What is final quest in Guild Wars?

Question: What is the quest (or quests) which may be deemed as final in Guild Wars? I am not talking about missions. I am talking about quests after all missions. What is the must final quest?
Comment: I wouldn't really say there was a final quest.
Answer: I am not entire sure what you are asking about in your question, but here is a list of stuff that may fall under what you are interested in:

Challenge and Elite (none storyline missions/quests) - Fissure of Woe, Underworld, Sorrow's Furnace, Tomb of Primeval Kings, The Deep, Urgoz's Warren, Mallyx.  These are are all elite missions/zones that grant unique greens, possibly minis, and other rewards is not related to the storyline.
The series of War in Kryta quests that were added in over the previous year or so which leads up to Guild Wars 2 are probably the latest in terms of story (and possibly the final story related missions).
The Vision of Glint quest series can be done after the prophecies missions.
The final quests for each campaign are: Hell's Precipice (prophecies), Imperial Sanctum (factions), and Abbadon's Gate.
The Eye of the North update has a direct link to events in GW2.  The final mission for EotN is A Time for Heroes.
Filling up your Hall of Monuments or maxing all titles (very challenging and impossible for certain discontinued titles) may be considered the final quest for some.

Updated as of 8/18/2011

hard mode quests that you can complete.
Winds of change, which is the Canthan equivalent of events and stories leading up to Guild Wars 2.
Comment: Don't forget about the titan quests! Also, in #4, those are missions.
Comment: Perfect answer thank you. If you think there are others don't hesitate to add your answer.
Comment: War in Kryta is also followed up by Hearts of the North, and later there will be something set in Canta.
Comment: @yx_ You may want to add that they're currently releasing Hard Mode versions of older quests, such as Villainy of Galrath and the Vision of Glint stuff. Winds of Change is also released now.

What is final quest in Guild Wars?


Unique Permissions messing up users access?

Question: Ok, I guess I need a quick brush up on the topic of Unique Permissions. I have a folder which has another folder (JSLib, CSS, Images), and 3 pages:
Folder A
 - Subfolder A JSLib
 - Subfolder B CSS
 - Subfolder C Images
 - HTML 1
 - HTML 2
 - HTML 3
Then a bunch of other Lists as web parts.
HTML 1 has it's own unique permission.

So the issue I am having is, folks can see HTML 2 and 3, only a few can see the HTML 1 (exactly how I want it).  However, the images from Subfolder A is showing as a broken link due to permissions (the "X" image) and the Javascripts are not working (accordion, tabs, etc.).  However, I can see all the images and the JavaScript functions are working perfectly for me.
When I broke inheritance from the HTML 1 file to give it a unique permission, did create all the issues for the other users?  I have site owner permission. When I broke inheritance for the HTML 1 and assigned the folks into it's permissions group, they are also having issues.

Hopefully this makes sense, I thought this breaking inheritance permissions was pretty straight forward, but I may be missing something.
Answer: have you checked the permissions for the subfolders (JSLib,CSS,Images) for those users who are facing issues in the HTML1 file..
may be the users are not having proper permission to the subfolders in which your css,js is placed..
Comment: thanks for the reply.  It looks like they all have the same permissions.  I just don't understand this SharePoint Permissions.  If someone has access to the Parent, you inherit the parent, you should have permissions..correct?  I can see everything, yet everyone else can't.  I just have to find out where this is breaking.  I've always had this issue with SharePoint...weird permissions issues.
Comment: Hi, I found out what my problem was.  The solution was found by a poster named James.  Here is his answer [link](https://sharepoint.stackexchange.com/questions/166933/when-i-upload-a-document-in-sharepoint-others-dont-see-it-even-though-they-have).  The individual images and scripts uploaded as _**Checked Out**_ automatically.  I had to go in and check them all in.  Now it's working for everyone.
Answer: See my response to the @Pradeep.  It wasn't permissions issues.  All the images and scripts that I uploaded were automatically set as "Checked Out".  Once I checked them all in, it worked.  The solution was from @james on the following post:
When I upload a document in Sharepoint others don't see it even though they have permission


Please allow including a full site in the StackExchange™ GlobalTag MegaBlender™ aggregation

Question: Wildcard support is a great step, however I'd like to propose going a step further.  For smaller sites, it isn't as necessary to limit things by tags because you aren't getting overrun by the immense traffic like on SO.  For StackExchange.com to truly be a place for aggregation, instead of just one more place to look at, it'd be great to be able to say show me everything from WebApps plus [sushi] on cooking plus [c#] on SO for instance.
Comment: I had the same thoughts on my comment on the blog post http://blog.stackoverflow.com/2010/11/tag-sets-on-stack-exchange/#comment-51695 I want to see the Android.SE plus the Android tag across all sites
Comment: I vote for this as well, especially when you consider that on young sites like Cooking, most members tend to really suck at tagging things correctly.
Comment: @Popular, see the comment on the question I linked to (your question).
Comment: ah, yes, also that.
Answer: Done.  Just click the add entire site link at the top of the "Add Tags" section to toggle into adding a site mode.
Also, as a counterpoint to Jeff's argument, I believe that this does fit in well with the philosophy of the feature, which is show me all the stuff I'm interested in across a bunch of sites.  Jeff's right that if you want to see every question, the right place to go is still that site, but maybe I want to aggregate several smaller sites and watch all of their new questions in one place.  Now I can :)
Comment: I'll get you Fullerton! And Emmett too!
Comment: Exactly!  Using Jeff's example "for the sites you don't live in, but you might like to visit there once in a while*:  this would describe cooking for me for example, but there isn't a set of tags on cooking I'd want to limit things too.
Comment: I think "smaller sites" is the key, as it takes a long time for a usefull set of tags to be created on new sites.
Answer: I don't think this fits well with the philosophy of the feature. It's about questions with specific tags, not all questions.
If you want to see every question on a site -- go to that site!
Tag sets are really for the sites you don't live in, but you might like to visit there once in a while.