When the angle of incidence is less than the critical angle, why is some light still reflected?

Question: When the angle of incidence is less than the critical angle, why is some light still reflected? When the angle of incidence is greater than the critical all light is reflected, why is not all light transmitted when it's less?
Comment: A material always have emmision + absorption + transmission + reflection = 1
Comment: That is not always the case. There is a special case in which no light is reflected.
Answer: Light is an electromagnetic wave, and as such is governed by the Maxwell equations. These equations (considering only the linear mediums 1 and 2) give certain boundary conditions:
$$
(\text{i})\ \epsilon_1E^{\perp}_1=\epsilon_2E^{\perp}_2\ \ ;\ \  (\text{ii})\ \bf{E}^{\parallel}_1=\bf{E}^{\parallel}_2
$$
$$
(\text{iii})\ B^{\perp}_1=B^{\perp}_2\ \ ;\ \ (\text{iv})\ \frac{1}{\mu_1}\bf{B}^{\parallel}_1=\frac{1}{\mu_2}\bf{B}^{\parallel}_2
$$
These conditions determine how the light behaves at the surface, and note that they imply the total E-parallel component in medium 1 is equal to the E-parallel component in medium 2. Mathematically,
$$
\bf{E}^{\parallel}_1=\bf{E}^{\parallel}_{\text{incident}}+\bf{E}^{\parallel}_{reflected}=\bf{E}^{\parallel}_{transmitted}
$$
This happens independently of the angle of incidence, hence there must be a reflected wave in order to have a refraction. You can calculate the amplitude for each of the components and check that they obey it. I suggest reading chapter 9 of Griffiths' "Introduction to Electrodynamics" for a better understanding.
Comment: Also, even for the case of total reflection, there _are_ non-zero electric and magnetic fields that exist in medium 2, but they die off quickly (i.e. evanescent) and do not carry any energy.
Answer: In the general case, there are 3 components, namely, the incident light, refracted light and reflected light. However, when the light is plane polarised along the plane of incidence,one can show using wave theory of light that if $E_I,E_R,E_T$ denotes the amplitudes of incident,reflected and refracted electric fields, then the following holds:
$E_R = \frac{(\alpha - \beta)}{(\alpha + \beta)}.E_I$, $E_T = \frac{2}{(\alpha + \beta)}E_I$
where $\beta = \frac{\mu _1 . n_2}{\mu _2.n_1}$ ($\mu _i$ denote the permeability of the 2 media and $n_i$ denote the refractive indices.)
and $\alpha = \frac{cos (T)}{cos(I)}$ ($T$ denotes the angle of refraction/transmission and $I$ denotes the incident angle).
Neglect the mathematics if you don't want them, but just notice that for the case $\alpha = \beta$, $E_R$ becomes zero. So there is no reflected ray. This happens for a particular angle of incidence given by:
$tan(I) = n_2/n_1$. This is known as Brewster's Angle. At this angle, plane polarised light(w.r.t the plane of incidence) is transmitted 100% into the second medium. This can be shown using rigorous maths, and you can read that up from Griffith's Electrodynamics as mentioned in the other answer by Renan.


$\beta\mathbb{N}$  vs $\beta\mathbb{Z}$

Question: Just started learning the Stone-Cech compactification of discrete groups this week. My motivation comes from a question on $\beta\mathbb{Z}$. Surprisingly, I realized there are muchhhh more literature devoted to $\beta\mathbb{N}$ than to $\beta\mathbb{Z}$. I wonder why is that? After all, algebraically $\mathbb{N}$ is a semigroup while $\mathbb{Z}$ is a group, and as discrete topological spaces they are homeomorphic. From your experience, how far $\beta\mathbb{N}$ and $\beta\mathbb{Z}$ are different in behaviour? Also, is $\beta\mathbb{N}$ ( or ($\beta\mathbb{N}\setminus\mathbb{N}$) easier to deal with?
Comment: Not an answer, but: have you looked at the book of Hindman and Strauss for some of the striking properties of $\beta {\mathbb N}$? I think David Gunderson might have a copy.
Comment: Hi Yemon. Yes! The library has a 2012 copy of it! In fact, it's open in front of me right now, working on chapter 3! Seems like I need a quite good deal of this book! Thanks for mentioning it!
Answer: $\beta\mathbb Z$ consists of just two copies of $\beta\mathbb N$, one at "positive infinity" and one at "negative infinity".  It's generally easier to think about just one copy rather than both, so people tend to write more about $\beta\mathbb N$.  The advantage you mentioned for $\mathbb Z$ over $\mathbb N$, namely that the former is a group while the latter is only a semigroup, doesn't carry over to the Stone-Cech compactifications, both of which are (under the natural extensions of the addition operation) only semigroups.
Comment: Are there any complications when it comes to the semigroup structure? that is, when we let the "negative infinity" bits of $\beta Z$ act on the "positive infinity" bits of $\beta Z$, does anything tricky/interesting occur?
Comment: @Yemon: One thing that may not be obvious about the interaction of positive and negative points at infinity is that, when you add one of each, the sum is infinite in the same direction as the second summand.  (That's assuming you use the "usual" convention, whereby the sum is a continuous function of the first argument.  Some people prefer the opposite convention, in which case "second" should be "first" in int the unparenthesized part of this comment.)
Comment: Which of the group axioms fail for $\beta\mathbb Z$?
Comment: @unknown (google): $\beta{\mathbb N}$ isn't cancellative, so $\beta{\mathbb Z}$ certainly isn't.
Comment: @unknown: Associativity is fine for $\beta\mathbb Z$ but cancellation and therefore existence of inverses fail badly. There are lots of idempotent elements in $\beta\mathbb N and therefore in $\beta\mathbb Z$, whereas in a group the identity element is the only idempotent.
Answer: Since $\mathbb N$ and $\mathbb Z$ are homeomorphic, so are $\beta\mathbb N$ and $\beta\mathbb Z$, though of course the semigroup structure will be different.
Comment: @unknow: It's not what I am looking for. I appreciate your comment though. Thanks! As you also mentioned, the extension of the homeomorphism between $'matbb{N}$ and $\mathbb{Z}$, shows that for the topologist these two spaces are the same. I am wondering how differently can these two objects $\beta\mathbb{N}$ and $\beta\mathbb{Z}$ behave? I consider the Stone-Cech compactification of a discrete semigroup as a special well-studied case of a more general notion namely compact Hausdorff right topological semigroups. So to me it's not only a topological object but also algebraic.
Comment: I'm sorry, I didn't see (and still don't see) where the OP said that $\beta\mathbb N$ and $\beta\mathbb Z$ are homeomorphic.
Comment: I stand corrected - I was reading too quickly. I still think this is not a particularly useful observation in the present context, but perhaps I am mistaken and it is useful to the OP
Comment: [deleted earlier erroneous/unfair comment]

$\beta\mathbb{N}$  vs $\beta\mathbb{Z}$


GFCI receptacle vs GFCI breaker

Question: In the year 2021, almost every circuit requires GFCI and/or AFCI per NEC. Let's consider bathrooms.  I believe AFCI is not required (true?) but GFCI is required.  I understand that GFCI protection can be either via receptacles or breakers.  There are pros and cons for both. So my question is directed to anyone who knows how new homes are being wired.  Are bathroom outlets protected by receptacles, breakers, or maybe both?
Answer: As far as GFCI requirements in a bathroom all bathroom receptacles have been required to be GFCI protected for  many cycles NEC 210.8.A.1.
currently AFCI's are not required in bathrooms and I would suggest not getting a dual function device as AFCI technology is still not mature and there are problems, since my last job change I won't be wiring homes anymore but I can say that AFCI's have many more problems than GFCI's ever had.
Now to answer your question, a majority of electricians use point of use GFCI devices, most use receptacles but a few use dead face devices (a GFCI device that has no outlet just test and reset) by stating point of use that means the device is in the bathroom.
Very few use breakers but some do the negative is that you have to go to the service panel to reset, but some see this as safer because you would not be as wet doing a reset at the panel as a justification for breakers.
I have seen no studies stating one is safer than the other but point of use GFCI reset is more convenient, I have used WR rated GFCI's in bathrooms because of the high humidity possibility to extend the life of the device.
Answer: There are no pros for using a GFCI breaker. It's stupid, IMHO, to combine functions into a single point of failure, thus having to replace a much more expensive device. Another con is that you have to travel a much longer distance to the centrally located panel to reset the GFCI should it trip.
Around here, a typical GFCI breaker costs about $60, and a GFCI receptacle costs about $15 for a name brand (like Legrand), and about $8-10 for a cheapo brand, which, in my experience, is not worth buying. And both a GFCI receptacle as well as a breaker, can protect an entire circuit just the same.
EDIT:
As for your question regarding AFCI protection, they are not (yet) required in bathrooms. And rather than getting into the details here, please refer to this article by Eaton Corporation.

GFCI receptacle vs GFCI breaker


MVVM Commands - one command for everything or multiple commands?

Question: In my last company, on handling view commands, in the ViewModelBase there were one central command implemented, like
public ICommand ToolCommand { get; set; }

And in the ViewModelBase, it's been initialized, and all buttons hooked to this Command were differentiated by its Command Parameter:
public ViewModelBase()
{
    ToolCommand = new RelayCommand<String>(Execute, CanExecute);
}

In the view model base, the Execute and CanExecute functions were virtual (implementing such generic commands like Close, and so on), and in the derived classes, the Execute and CanExecute function was a big switch, extending base functionality, looked more or less like this:
public void Execute(String parameter)
{
    switch (parameter)
    {
        case "Refresh":
          RefreshGrid();
          break;
        case "OtherStuff":
          Other();
          break;
        default:
          base.Execute(parameter);
    }
}

In these cases, when we just added a button, we added another switch case in the proper view models.
However in my current company, the rule is that each button has specific command property, like
public ICommand RefreshCommand { get; set; }
public ICommand OtherStuffCommand { get; set; }

, and initiated one-by-one:
RefreshCommand = new RelayCommand<String>(RefreshGrid(), _canRefresh);
OtherStuffCommand = new RelayCommand<String>(OtherStuff(), _canDoOther);

In the office we can't agree which is better in terms of compactness, beauty, debuggability. Surely we won't rewrite working parts because of its cost, but considering new projects we find hard to discuss which has more advantages.
Which and why of these two approaches is better?
Answer: I think using the switch statement with strings is a terrible idea for the following reasons:

Your commands can't take an actual parameter because you've used the CommandParameter to identify the command itself.
Your Execute and CanExecute methods become large blobs where it's impossible to tell if you are actually handling all of your commands since you have to cross-reference the ViewModel with every single XAML file that is bound to it.
Some commands do not need a CanExecute.  If you have each command as an individual property, it's very easy to tell which commands support CanExecute and which do not.  With the switch statements, it's a lot harder to determine that.
It is very difficult to override behavior for a single command in a derived class.  If you had a child ViewModel class, the only way to override behavior for one command is to copy the entire Execute(String parameter) method and change the one case statement that you're interested in.
Static analysis tools cannot tell you that your command binding in the XAML is wrong because your CommandParameter is just an arbitrary string.

I think that the downsides to the switch statement with string approach are so strong that I would encourage refactoring existing projects to not do it that way.
Answer: I think the key thing to consider here is the View im absence of the ViewModel.
Ie. In your view you will have bindings for the various buttons etc and you need to distinguish these.
Your choices will be bettween
NamedCommand(parameter)
GenericCommand(name, parameters)

I think its fairly obvious where a parameter becomes a command name rather than a parameter to the same command and in those cases I think you should prefer NamedCommand.
Although I can see there might be edge cases where the naming is difficult
Answer: The whole idea behind a Command is that it's not specific to a view. You may want to execute the same command from a button on your view, or a menu option, or from a right click context menu, or from a myriad of other UI elements. By creating specific command classes, you gain Single Responsibility and reusability. I wouldn't recommend having your view model's define the behavior of their commands. You'll just end up copy/pasting code throughout your code base.


How to scrub a document of all text between brackets with find and replace

Question: I have a log file and I need to find all instances of <password> hash here </password> and remove the hash and replace it with some dummy text like aaa-aaa-aaa-aaaa.
The recurring search argument is anything that matches a bracket that starts with <password> and ends with </password>. All the hashes being replaced will be different.
What's the easiest way to go a bout this? The log is on a windows machine. Probably easiest would be to use MS word for me, unless it's achievable with wordpad, notepad, or some other light weight editor like textpad.
thanks
Answer: You can do it with SciTE (very lightweight), but any editor that supports regular expressions should be fine.
Use the replace feature ->
 Find what - <password>.*</password>
 Replace with - <password>helloWorld</password>

Regular expression - yes
Comment: textpad can also do this.
Answer: FARt.exe
 http://fart-it.sourceforge.net/

Command line for you
 fart "filepath"  "<password> hash here </password>" "<password>sdasdadaasd</password>"


How much ground was prepared for Riemann so that he could conjecture Riemann hypothesis?

Question: Although I do not doubt in Riemann˙s originality, I would like to know how much complex analysis was developed up to the day when Riemann conjectured what is today called Riemann hypothesis and how much itself was the theory of zeta-functions developed up to that day?
Comment: This is a bit broad for this site, but I think all the information you want is contained in the History section II of the [Bombieri's description of the Millenium problem](https://www.claymath.org/sites/default/files/official_problem_description.pdf). If not, perhaps you can narrow down the question after reading it.
Comment: Apart from other aspects, it is my impression that "complex numbers" and/or "complex analysis" were partly viewed as "convenient fictions" in those years, so, to my mind, a great part of the conceptual novelty was that non-real zeros of functions had very tangible (non-dismissible) real-life impacts. Such broader-context-issues were not addressed so much in Bombieri's essay. Is the complex-analysis context what you're wanting, specifically?
Answer: Riemann wrote his paper on the zeta-function in 1859. He was the first person to consider the zeta-function in the complex plane, first for ${\rm Re}(s) > 1$ and then he worked out an analytic continuation to all of $\mathbf C$ except for a simple pole at $s = 1$.  Before Riemann the only way the zeta-function was used was on the real line: real numbers bigger than 1 for Chebyshev and Dirichlet, and positive and negative real numbers by Euler using divergent series.  Riemann's use of complex analysis in his paper on the zeta-function was unlike anything anyone  had done before.  For example, his use of Fourier inversion to replace an integral on the positive real line with a vertical integral in $\mathbf C$ was new.
There were three majors figures in the development of basic complex analysis: Cauchy (1810s-1850s), Riemann (1850s-1860s), and Weierstrass (1850s-1880s). All Riemann had available to learn complex analysis was the papers of Cauchy, which were rather disorganized since Cauchy himself did not realize until the 1850s the many ways that complex-valued functions of one complex variable were far more special than functions of two real variables. The main ideas Cauchy had were his integral formula and his residue theorem, but in a much more primitive form than the way we know them today.
Riemann figured out a lot on his own: his dissertation in 1851 was about Riemann surfaces, going far beyond what Cauchy had been doing.  Cauchy's focus was on using contour integrals and residues in the complex plane, mainly to compute real integrals. Riemann's vision was totally different and in many ways much grander: use the Cauchy-Riemann equation (PDEs) and conformal mappings, analytic continuation,  and study functions geometrically rather than by relying on formulas for their values everywhere. Weierstrass did everything with power series rather than with integrals or geometry. The ground in complex analysis that was prepared to let Riemann conjecture the Riemann hypothesis had been developed in large part by Riemann himself.
See Section 5.10 of Bottazzini and Gray's "Hidden Harmonies - Geometric Fantasies: The Rise of Complex Function Theory" for a summary of Riemann's paper and a description of what was novel in it.
Answer: As a further data point, you might want to look at André Weil's article "On Eisenstein's Copy of Disquisitiones" (Advanced Studies in Pure Mathematics 17, 1989, pp. 463-469), where he suggests that Eisenstein might have influenced Riemann when he wrote his paper on the zeta-function.
Comment: Weil wrote in that paper that Eisenstein had an unpublished proof of the functional equation of $L(s,\chi_4)$ using Poisson summation, which Weil thinks may have inspired Riemann in using Poisson summation. In contrast to the initial definition of $\zeta(s)$, note that  $L(s,\chi_4)$ and $L(1-s,\chi_4)$ both make sense for real $s$ in $(0,1)$ from the original definition of $L(s,\chi_4)$ as a series, so you can consider a functional equation relating values at $s$ and $1-s$ from the definition as a series. That is not the case for $\zeta(s)$ as $\sum 1/n^s$.


How to report non-significant multiple regression?

Question: I tested my main hypothesis with a multiple regression, which (unfortunately) turned out to be not significant at all.
I am not sure in how to report the results now.
Which parameters should I include and how do I phrase the findings?
Answer: This is a profound question.   At some time, it may be worth reading the American Statistical Association discussion on p-values: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187603/
It gets more complex when you are modelling.  With observational data, it is possible to try a vast combination of including / excluding predictors, adding interactions and so on. You can also have confounding whereby omitting predictors can mask an import effect.  A lot of work is done in terms of model search, with techniques such as Lasso.  However, you say you had a specific hypothesis (which you may have in an experimental setting).   Failure to reject the null hypothesis here could be due to the null hypothesis being true, you having insufficient data, or any one of several technical assumptions failing.   So I think you report it as saying you did not reject the null hypothesis. Especially if your sample size is small, I would report the summary statistics, and it really depends whether you think what you have could be important.   If I did a study on poison, with two groups of three animals, I would not have a significant result. But I would have three dead animals in the treatment group.  That is important, so I would report that. It is up to others to read this report and decide whether further investigation is appropriate.
I don't know what you mean by testing a main hypothesis. Are you looking at the F-value for the overall model fit, or at the Wald tests on the individual parameters?
Answer: Simply: you use the same language as you would to report a significant result, altering as necessary.
I had the honor of collaborating with a much regarded biostatistical mentor who wrote an entire manuscript prior to performing final data analysis, with just a placeholder for discussion, as that's truly the only place where discourse diverges depending on the result of the primary analysis.
The "penultimate" manuscript read something like the following"
"The multivariate relative ratio of caries for adolescent residents served with municipal fluoridated tap water was XX.X compared to adolescents not served with municipal fluoridated tap water, 95% CI XX.X - XX.X, p-value = x.xxx. These data (do not) provide statistically significant evidence that municipal fluoridation of tap water can reduce incidence of caries in an adolescent population."
Obviously, only at the point of discussion do we start to talk about any need for confirmation, follow-up, or even policy change.
For a "negative" result, you should devote some discussion to the following:

Was there adequate power according to preliminary power estimates? For instance, if you expected a 0.5 RR but the resulting RR is 0.7, post-hoc power is down for the same $n$. The meaningful discussion is whether you got the right $n$ in your sample to have a good test had the RR been 0.5.
Were there undetected interactions in the data? Are there alternative measures of effect to consider? Present a concise and relevant summary of sensitivity analyses.
Was the study meant to be hypothesis generating or hypothesis confirming? If the latter, and with adequate power, you might consider reporting the "negative" finding as a "positive" one. E.g. in the water case, "This study does not support the hypothesis that municipal fluoridation can reduce incidence of caries in minors."
Answer: There is a move, I do not know where it lies now these things tend to go back and forth among methods people, to simply ignore p values.  The reason is, or at least one reason, that a variable can be statistically significant and have a very small effect size. Statistical power, and likely generalizability is another issue. It may be there was a significant effect and your power was to low to pick it up. At the least you should report your power.


I got angry with my mom suddenly

Question: Assalamualaikum. My mom is the person that i am very close to. I was with her all the time and still am. My mom gets angry for many reasons. Sometimes because i did not do the work properly like dishes or me being late to go for ghusl and many more reasons. I promise you i never want to shout at my mom. But i cannot seem to hold my tounge. I hate myself for not able to hold my tounge and not talk with my mom rudely. Today i was delaying my time for a bath. My mom came and hit me. I got angry and told her " ill go when i want to" She again hit me. I told her to put down the ruler in a rude way. She got more angry. She doesnt want to talk to me now and i am trying make her laugh. She laughs but still she does'nt talk to me. I don't even know if i deserve forgivness. Whenever i get hit i act very rudely. I don't know why. But i really love my mom. So does my mom loves me. But we both share a similar thing that is our anger. My mom cannot control hers. But i should control mine. If i ask forgivness from Allah. Will he forgive me??
Answer: Ask Allah for helping you to be good with your mother. And make a good Dua for your mother. Tell your mother that she should not always hit you. Tell her that you love her. And after you talk bad to her, you should apologize. It is normal to get angry when someone hits you. But you should be patient and always try your best.

I got angry with my mom suddenly


Join two .xoj files

Question: If i annotate a pdf with xournal and then annotate the same pdf on another pc, also with xournal, is it possible to join these two .xoj files ?
I tried to google the problem, but found nothing about this.
Answer: If you do not need to edit the annotations later on, the easiest way is to export one of the xoj files to a new pdf and use this as the background for the other one.

Join two .xoj files


Restoring plastic chairs

Question: Before I take them to the dump, is there anything I can do to restore them? Are there any chemicals to clean them? I was going to repaint them using spray paint but it was taking too long and almost a full can of paint and the chair (not pictured) still looks like it will need a second hand.
Answer: Usually those chairs take obvious UV damage from the sun.  This can weaken them.  (it does the same to child car seats, one legitimate reason to throw old ones out).  If that's not a problem, the chairs are probably saveable...
...but you need to learn to paint.  One rattle-can should do all 3 chairs.  You went through a whole can because you're misusing it as a magical fixer, cleaner and surface preparer... And that does not work.
I would start by working each chair over with sandpaper, maybe 120 grit, to smooth off any oxidation and give a texture primer can bite into.
Then, well gosh, what do you have around and how much do you want to spend?  Myself I do enough woodworking to have West System epoxy on hand, it's not a paint but it's perfect for stabilizing a stressed surface like this. I would use either that or a 2-part epoxy primer (or garage floor paint) and paint that on thin, with a throwaway chip brush. It would probably be about $5 worth of West System to do those.  I like epoxy because I know it'll help stabilize and strenghen the chair.   If I didn't have that, then maybe an oil based primer like Rustoleum white. I don't think a latex primer would stick, and rattle-can paint won't stick to it.
Then after the epoxy cures good and plenty (do not stack them for a few days!), I would sand a second time probably with a Scotchbrite pad, just to give the surface some texture paint can bite into.  The surface should now be very uniform and hard and take paint well.
Then rattle-can it.
Comment: There is spray paint designed specifically for plastic furniture, and no primer is required.  Rust-Oleam is one of the manufacturers.  Example: http://www.homedepot.com/p/Rust-Oleum-Specialty-12-oz-White-Paint-for-Plastic-Spray-Paint-6-Pack-211339/202058471.  Krylon is another: http://www.krylon.com/products/fusion-for-plastic/

Restoring plastic chairs


Does commercial sour cream still contain live bacteria?

Question: Does commercial sour cream still contain live bacteria? A family member cannot consume them, so I am looking for a way to recognize sour cream without live cultures.
Comment: @rumtscho : sometimes giving the reason why you're asking is important ... eg, asking about gluten.  Answers might be different for someone with non-celiac gluten sensitivity vs. celiac's disease.  Someone might have questions about dairy for a number of reasons (kosher, vegan, dairy allergy, lactose intolerant, casein intolerant, etc.) and without being able to tell people about their specific case means we can't give them a good answer.  I'm not going to claim that their phrasing was the best, but removing all mention of motivations/conditions is a problem.
Comment: I totally agree with Joe. These are well known benefits that are undisputed in the medical industry. Knowing that the poster is looking for a particular type of bacteria is relevant to the question otherwise mold could be an answer.
Comment: The problem with this line of thinking is that people start answering with what they believe to be good advice about some condition, and others start upvoting it when it feels authoritative enough. If they are wrong, we end up with terribly misleading answers which can hurt someone. So really, the point here is that the OP should find out on their own, from medical professionals, what they should and shouldn't consume. If "searching for" vs. "searching to avoid" is important for this question, then the OP should clarify which one it is. But we cannot make recommendations what they should eat.
Comment: @Mia nobody is offended. We have our rules, and they can seem strange to new people at first. We know it's not easy, and that nobody reads pages of "how to post" before posting. So when somebody posts something which doesn't work well here, we try to change his post to conform to the rules, while keeping their original meaning intact as much as possible. If we knew how to make the process easier for new users without compromising the rules and leaving open the kind of question we cannot answer well, we would. Also, thank you for the clarification. The process is basically 1) you post, (cont.)
Comment: (cont.) 2) we look at it and see if it is OK by our rules. If it is not, it has to be corrected - but we know that it is hard for you to find a formulation which fits *our* rules, so 3) we do our best to remove the problematic parts. If the user is nice enough to come back and clarify, like you did, we can 4) add even more information, while wording it in a way which does not invite well intended but possibly misleading answers. When you spend some more time around, you will get a better feel for the site, read the help, and your questions will probably be a better fit from the beginning.
Comment: Hello Mia, please no health discussions here. It is OK to ask about the contents of a food, as you did. But saying that they are healthy, or asking whether they are healthy, or saying that they are good for people with a certain condition, or generally making any health claim is off topic. I edited that part out, the rest of the question is good.
Comment: I made a suggested edit with some additional information as to why it's relevant (in immunodeficient individuals, one may need to avoid L&A cultures).  I think it's important to have this information - since for many sour creams the answer is "maybe", that's a very different decision if you're searching *for* vs. searching for *not*.
Comment: I also rejected the edit, first because of the reasons I listed above, and second because it isn't even clear if the interpretation is correct. There are tons of fermented products which claim to boost immunity, the original wording could have referred to this and meant that the OP wants to look *for* live cultures, not *look to avoid* them. I know that we all have an understandable wish to help people, but when it comes to nutrition, it's better to close one question too much and tell the people to find the answer out from a specialist, than to answer one question too much.
Comment: I'm not intending it as a health comment. I love yoghurt and believe it is good for me. However, my mother has lowered immunity due to myeloma and cannot have cultured products. (The haematologist nearly had a fit when I suggested giving her yoghurt.) So I think it's a fair question. Sorry if I offended you.
Answer: Joe M.'s answer is correct that it's difficult to get this information, though you can always try contacting the manufacturer directly.  But in general I would assume that commercial sour cream still contains at least some live bacteria.
In the U.S., food packaging laws require sour cream produced with bacterial cultures to be labeled either "sour cream" or "cultured sour cream."  Sour cream produced without bacteria by law must be explicitly labeled "acidified sour cream."  ("Acidified sour cream" usually has an inferior flavor and generally tends to show up as ingredients in other things or occasionally in low-fat or non-fat varieties.  In any case, "acidified" here only means that acids were used at some point to help the process along, so it doesn't guarantee that cultures were NOT used.)
To my knowledge, sour cream is generally NOT heat treated after culturing (unlike some yogurt), which means that active cultures are probably still present in significant numbers in most "cultured" sour cream.
And even if it is "heat treated" as some yogurts are, I don't think sour cream could actually be "re-pasteurized" without ruining the texture, so it's very unlikely to find a "cultured" sour cream that has no live bacteria in it.  Products explicitly labeled with a "live and active cultures" designation have to meet a standard for a minimum of bacterial concentration, but other products that are "cultured" without that designation likely still have residual live bacteria unless proven otherwise.

Another thought to make a determination is to try to culture with the cream yourself.  Put a tablespoon or two of the sour cream in a few ounces of fresh pasteurized milk (or some fresh cream), and let it sit out at room temperature.  If the sour cream has active cultures, it will likely start to thicken significantly in 12-18 hours.  If the milk hasn't noticeably thickened within a day or so, it's less likely that it contains a significant number of active cultures (though not certain).
This is not a definitive test to rule out bacteria, but if the milk thickens noticeably, it's pretty likely the sour cream has some active cultures.
Answer: It's hard to get a straight answer online, unfortunately, as most sour cream manufacturers don't mention either way.  Daisy brand, for example (one of the mass-market brands that is relatively unprocessed) doesn't mention it on their website, nor do they on their containers, though some people have said they do contain live active cultures - but nothing reliable that I see indicates that.  Breakstone's mentions that their cottage cheese has prebiotics, but nothing about sour cream, leading me to think they probably don't.
A few brands pasteurize and then add back in the L. Acidophilus and Bifidus Regularis (or similar) cultures afterwards, presumably to improve taste as they continue to break down the lactose (similar to how some mass-market yogurts do so); for example, Organic Valley mentions on their website:

Our sour cream is a cultured blend of nutrient-packed organic cream and skim milk. When the sour cream is pasteurized and homogenized, active cultures acidophilus and bifidus are added to boost the tangy flavor and create a consistently dense cream. The active cultures also serve as probiotics to improve the microbial balance of your digestive tract.

If you're looking for a brand that specifically does contain live active cultures, you should look for a mention on the label.  Any brand that does not mention it on the label may or may not contain them.  The indication of live and active cultures is not mandatory, as far as I can tell; the National Yogurt Association has a voluntary compliance process involving a seal that indicates live and active cultures, for example, but it is strictly voluntary.
However, searching for a brand that does not contain live active cultures, your best bet would be to contact the manufacturers directly.  I don't think there's a reliable way to prove they don't contain them.  Fat-free sour cream is also unlikely to contain live and active cultures (as it's not really sour cream, it's a flavored gelatin product more or less).  Alternatively, you can cook the sour cream yourself (or only use it in cooked applications) to ensure the bacteria are not live, though in this case you should talk to your doctor to find out in what applications this may be safe.
Answer: Most do not because they have been pasteurized. You would need to look for an all natural "raw" product for it to contain beneficial probiotic bacteria. You may also find "contains live cultures" on the label. This goes for yogurts as well. You may want to try looking in a grocery store that has a good sized natural food section or a health food store.
Comment: You certainly don't need "raw" (or non-pasteurized) in order to have live bacteria; said another way, a pasteurized product *can* have live bacterial cultures. As in @JoeM's answer, pasteurization can happen before or after culturing/inoculation. If cultured *after* pasteurization (as is most yogurt) you'll be left with the (desirable) "live and active" bacteria even in a (previously) pasteurized product.
Answer: They usually do, but those are probiotics generally.


Square E-commerce Api integration to clients website

Question: Sorry if this is a simple question but I am trying to understand the best way to do this and I am new to Square development. I have a customer who has the Square chip card reader device on their cell phone and they are taking credit cards today. They also have a website which is using a oscommerce shopping cart and authorize.net gateway for processing orders on their website. What they want to do is just use Square and change the website so it integrates with their existing Square account. I understand the basic process of how to do this with the E-commerce API but I am a little confused on the developer / merchant Credentials.
This is a one off development for them so I do not think I want to use the oAuth method.
If they are a merchant today do they have to sign up under the developer area and create a app using the Application Dashboard so that they have a personal access token and application ID that I would use on their website? ( I already signed up and have a developer account)
What information about a sale is shown on their Square account once I integrate the secure SqPaymentForm payment form onto their website? Today all the details on the order are in the shopping cart such as what the customer ordered, the shipping address etc. Is this now going to appear on the Square account for them or do I still need to maintain this information in the shopping cart? It would be good if they could use a single interface such as the Square account.
thanks for your help.
Answer: If you don't to use OAuth, you'll have to have the merchant go to the Square Developer Portal and give you their personal access token and application id.
There are many different ways you can implement an online store, so where the information lives is all up to you. You probably want to keep your existing shopping cart functionality and just implement square for the payments, as that will likely be easiest and ensure you have all the data you want.


How to get exact call time?

Question: How can I get the exact time that a specific call took place? If I go to "recents" in the phone app, I see entries with times that read like Mobile, Yesterday. I need the exact time, down to the minute.
Comment: If you click on the specific call in the call log, it should take you to a screen that shows the exact time.  What kind of phone do you have?  OS?  A few extra details would help out tremendously
Comment: Nexus 5, Android 5.0.1
Answer: For Android 5.0.x Lollipop:

Either on "Recents" or "Call History", tap the entry you want to see. It will open a mini-menu under the entry with options "Call back" and "Details".
Select "Details" to see the call details.
From here, you can see the time when you receive/miss a call, and also the duration of the call.

Click the image for larger variant
Answer: In addition to Andrew's answer, you need to click the entry and not the picture of the contact for the mini-menu to appear.  I was clicking the picture of the contact, and it pulls up the contact info - not the call detail.

How to get exact call time?


On being created in pairs

Question: It is said in Islam that we are made in pairs. Then why do many end up living their lives alone? My beautiful and highly educated aunt remains unmarried till today. We all did our best to arrange a good marriage for her but could not succeed. She has been a pious woman her whole life and never engaged in relationship. She is tired now and refuses to met any other prospective groom. It is highly unlikely for her to married especially now since she is approaching 50. I do wonder, whether we lost something in translation or something we could not understand properly about "being created in pair". Will love to know opinions of my brothers and sisters here and educate myself in this regard.
Answer: The reason why people don't get married sometimes is they have strong criteria , they reject potential partners that was available for them. . It is highly recommended to get married but people make their own choices . They prioritize other aspects of their life such as education or career meanwhile all these aspects are achievable when you have husband or wife. They also don't want to marry divorcees or they want to marry financially strong people. They prioritize physical attributes more than how someone's character is. The list goes on ...
When Allah talks about we made you in pairs , it is talking about men and women. Union and each of them completing each other.
It is not Allahs error that people don't get married but perhaps choices of both male and female.
Comment: Thank you brother, especially for letting me think about this in a different perspective. May Allah bless you.

On being created in pairs


I have a Samsung portable SSD and can't open

Question: My laptop right now runs Ubuntu Kylin, and has no Windows on it after accidentally wiping it when I updated the Ubuntu version. I'm trying to access a SSD from Samsung that used to work fine with windows.There's an .exe file to activate it.. However, right now I can't seem to get the file to open. It opens briefly and then closes. I've tried installing exfat-utils which I read somewhere solved other people's problems, but still I'm having no relief to my issue. I've tried using Wine, but I'm unfamiliar and can't get that to operate properly either.
Comment: Yeah, I noticed that too, I was wondering if it were possible with all the creativity that goes on with Linux, hoping that there's the chance that someone's figured it out. I read some other posts, and someone on Fedora seemed to have gotten it. Mine starts, but quits before really working.
Comment: SSD or SD card? Quite different. If the latter, what size? exFAT support required only for +64GB. What file? A Windows executable does NOT work in Linux. Some Windows programs *may* run with Wine but not all. Please edit your question in a way it makes sense, i.e., provide actual information about your intended result.
Comment: It's an SSD. I'm trying to run this .exe so that I can use it as a portable HD. It has 1TB, but it won't run right now since I'm stuck with Ubuntu. Is it possible to somehow open this program so that I can use the files inside? I think the encryption technology might be making it more difficult.
Comment: If it's a Windows proprietary encryption software then you need Windows. Anyway, and again, what .exe? What software is that?
Comment: The .exe is just the app that comes installed with the Solid State Drive. When you plug it into the usb, it can be installed quite easily. However, the Linux OS is making it hard to access the files. The software seems to be part of Samsung's design to let users read files that are encrypted on their modern SSD's.
Comment: Yes, I already know that. I asked again what app is that, what name, etc... I doesn't matter that much anyway because, again, you need Windows. It's NOT the "Linux OS" that's making it hard, it's the manufacturer or whoever decided to use a Windows proprietary software for that.
Comment: Not sure...the file that I want is called Samsung Portable SSD.exe, and there's a folder called Samsung Portable SSD.app that doesn't necessarily lead anywhere.
Comment: http://www.samsung.com/semiconductor/minisite/ssd/download/portable.html   <- As you can see Samsung supports Windows and MacOS only.
Answer: Samsung's proprietary software appears to be only for encryption. You won't be able to access any encrypted files on the drive from Linux since Samsung doesn't support that.

If the drive is encrypted and you don't have any (valuable) data on the drive or moved it somewhere else (temporarily), you can repartition, reformat and use the SSD in Linux without additional software.
If the drive is not encrypted you should be able to use it in Ubuntu right away or at least after installing the exfat-fuse package. If you can't, please edit your question or open a new question and include the output of lsusb, sudo lsblk -f and a screenshot of the drive as seen by GParted.

If you want to encrypt your data on Linux (or any operating system really), it's always better to opt for vendor-independent, non-proprietary solutions. Popular examples for disk encryption system on Linux are

LUKS (Linux and BSD with cryptsetup, Windows with LibreCrypt (beta), OS X only through Linux guest system) and
TrueCrypt/VeraCrypt (Linux, BSD with cryptsetup, Windows, OS X).
Comment: https://paste.ubuntu.com/23278441/
Comment: Could you please [edit your question](/posts/832082/edit) if you want to add or clarify something? The comment section is not suitable or meant for follow-up Q&A or extended discussion. I also need the output of `lsusb`. Thanks.
Answer: I found a workaround, not a solution. But it works fine for me.

Connect the SSD to a USB-Hub with external power supply.
Connect the USB-Hub to a windows computer
Start the samsung SSD encryption tool in windows as usual. The encrypted partition will be visible.
Disconnect the USB-Hub ONLY from the windows computer, leaving the SSD connected to the power provided by the hub.
Connect the Hub to your Linux-System.
Done - the encrypted partition is visible!
Comment: You should report this to Samsung as a security bug.
Answer: Sorry to hear that; my heart sank every time I read about people running into such or similar ordeal.  I might be a little too late to help you but would like to share a little, hoping to help someone Googled here like I did.  I have a T5 SSD from Samsung too.  I started with DOSv3 and Windows XP was my last personal OS and then upgraded to Linux!  For working purpose still stuck with Windows 10.
In short, what I would have done:

Install Windows on:
1a. Original PC or
1b. Similar spec PC or
1c. VirtualBox
If an encryption key was saved/extracted previously, use that for recovery with the application program.
No Encryption Key? Hopefully you can regenerate that from the program by using the same 'credential' you provided when you first encrypted the disk. That likely would work if using 1a. above.
Couldn't get Windows OS, see if your SSD support Android or MacOS.

A longer read:
You need Windows because an .exe application runs on that OS.
Firstly if the encryption method originally generated a key that you have saved/extracted into a file, your chances of recovering from it is higher, even on different hardware/platform. If not, hopefully you could still regenerate the same key from preferably the original PC - better chances; or a similar configured PC. This all depends on how vigorous the encryption method is. A side note btw, it's 20190918, Samsung SSD T3/T5 hardware encryption was discovered to have flaw in its implementation.  If you have a hacker friend.
Have the key if one was generated. Reinstall Windows back to the same PC if possible, or else a similar hardware spec PC. A last resort to look at would be a virtual machine installation using VMware or VirtualBox.
Still another possible solution for SSD that support 'multi-platform' is to try using those other OSs if you have access to them. For example, the T5 can also be run on MacOS and Android. Search for 'Samsung Portable SSD' in Play store.
Just a little more about the encryption and the 'Encryption Key'. Strong encryption method's encryption key might be platform and system dependent. If the key was originally created with hardware IDs on CPUs/NICs and with Names like System 's or User's Name or any other combinations, re-creation of such key might need the original hardware and software setting.  As this make the encryption less portable, some encryption algorithm allow the saving/exporting of such key for disaster recovery or system migration.
Lastly, it is not Linux's fault that Samsung didn't support at least some major distro like Ubuntu, Red Hat, Debian, SUSE ...
Hopefully this solve your problem and back up those important data to a Non-encrypted media, if possible. If you need encryption, perhaps look into an open source Linux-friendly yet multi-platform solution like Veracrypt.
Answer: if you have access to a windows, android or Mac system you can temporary disable the encryption of the use by using the Samsung tool. It's a matter of seconds. after disabling you have full access from linux. After using the ssd on linux, you can enable the encryption again on windows, macOS or android.
Answer: The encryption file (.exe) won't work on linux you have to do it on windows. I had this problem with my 1tb Sandisk portable SSD and it has a SecureAccess .exe file but, I couldn't get it to work on linux. Then, I tried wine and it still didn't work so I deleted the files. You can encrypt your files on the drive using linux and whenever you want to use them on another machine just decrypt them on your linux machine. Or you can lock the file and if you have administrator privileges on the other system unlock the file when you want to use it.
Answer: I recently purchased a Samsung T7 portable SSD shield and successfully connected it to my Ubuntu 20.04 machine. The device was detected without requiring me to use a Windows machine to disable the password protection.
Comment: Different situation, Ray.  Jared was trying to access data encrypted under the Windows OS from Ubuntu.  Looking for a means of running the "front door" executable.


solve this problem using Pythagorean identities

Question: $$\frac{\sin(\theta)\cdot\tan(\theta)}{1-\cos(\theta)}= \sec(\theta)+1$$
I need to prove that both sides of the equation are equal to each other, we are supposed to be using Pythagorean identities to help us solve.
Comment: Welcome to MSE! It is very helpful to show the work you have done as it helps responders get to the specific issue as opposed to rehashing items you already know. Regards
Comment: Down-voting a question by new user is not a good sign of welcoming.
Answer: Convert both tangent and secant to sines and cosines, and simplify.  You should get an expression equivalent to $\sin^2+\cos^2=1$.
Answer: Hints: Recall that $\tan\theta =\frac{\sin\theta}{\cos\theta}.$ Given the Pythagorean identity, how can we rewrite $\sin^2\theta$? What is the factored form of a difference of squares?
Answer: On the lhs, convert $\tan(\theta)$ to $\frac{\sin\theta}{\cos\theta}$ and replace $\sin^2(\theta)$ with $1-\cos^2(\theta)$. Simplify.
Answer: Note that your equation is equivalent to
$$
\sin(\theta)\tan(\theta) = (\sec(\theta) + 1)(1 - \cos(\theta))
$$
This is equivalent to
$$
\sin(\theta)\tan(\theta) = \sec(\theta) - 1 + 1 - \cos(\theta)
$$
Now write the $\tan(\theta)$ on the left hand side as $\sin(\theta)$ over $\cos(\theta)$. Try to multiply both sides by $\cos(\theta)$. Then simplify.
Answer: Use $\tan\theta=\frac{\sin\theta}{\cos\theta}$ and then $\sin^2\theta=1-\cos^2\theta$


What's the (economical) advantage for a company by paying an employee severance payment short before retirement

Question: Given following situation
A Company has an employee (Bob) who will retire in 3 years. The company decides to save costs and therefore does downsizing. They offer Bob an severance payment in the amount of 3 annual salaries, if he leaves the company.
  Question
Assuming that Bob is a valuable employee who does a good job - how does it make sense (for a company) to let him go and give him the same amount of money as when he still worked for the company?

If relevant: we assume Bob lives in Germany.
Comment: Not being familiar with Germany, could you clarify how much taxes a company pays for an employee? In France, it's expected that a company pays about as much in taxes as it gives the employee, so in your scenario the company would save 50% of expenses.
Comment: In Germany, tax needs to be paid on severance payments, but, in most cases, no social security (e.g. https://www.finanztip.de/steuererklaerung/abfindung-versteuern/, in German). As social security payments are approx. 40% of total salary/wages, paid half by the employee and half by employer, paying €10K severance gets Bob €10K minus tax. Paying €10K salary costs the employer €12K including social security and gives Bob €8K minus tax. Giving Bob €8K severance is still a good deal for Bob (he can stop working) and saves the employer €4K.
Comment: @MatthieuM. in Germany the additional costs of employment apart from the gross salary are about 60-70 percent, too. Even though taxes are paid by the employer, they do it out of the employee's pocket. It's social security and such, that increases the total cost. - BUT: It is pretty much irrelevant, if you pay that in one year or over the course of three years.
Answer: If Bob is actually a valuable employee this probably doesn't make sense.
However it is possible that the things Bob is good at just don't have a market any more. So his work could be good but it is not valuable (any more). Training his to do new things is not considered worthwhile with his upcoming retirement.
If he continues to work he probably also needs an office or similar amenities that are not needed if he is let go.
So one could construct examples where it is worthwhile to pay him his full salary until retirement as severance pay but it wouldn't be a typical situation.
Answer: You should also consider that firms often need to use other factors together with employees/labor.  Steel manufacturers can't produce steel just by hiring workers without some steel furnace/capital. If one furnace becomes too expensive to maintain it could be cheaper to scale down and using that furnace even if the company will still pay all the employee wages because this still reduces costs. In such cases it might not matter how good the employees are at their job.
Answer: If bob is leaving in 3 years, it may be worth it to pay him 3 years salary to retire early. If his skills/area of expertise are far out of date, it might be better to go ahead and get a new, younger person started with updated skills in a new area of business, and in 3 years that new person will have a lot of experience.
A business could also do this just to trim down overhead. Bob has to have a manager, consume office supplies, require a desk/cubicle (in downtown areas this can be pretty expensive), require tech support, need new computer equipment, require medical insurance or other govt mandated taxes (payroll tax in US). All of this can add up to over 100% of Bobs salary, or in other words Bobs salary is only 50% of the total cost to keep him employed and not replace him.
Answer: tl;dr privatizing gains and socializing costs.
The other answers already list a number of costs which are no longer applicable, especially the common costs for having an employee (manager, office, ...).
Payroll tax (Lohnsummensteuer) was abolished in Germany from 1980 on, due to its negative effect on employment. It was deemed better to have an employee pay income taxes and the social security duties by lowering the cost of employment.
There are four big social security duties in Germany. For people with income the payment is a percentage of the income, shared by employer and employee.

Rentenversicherung (old age pension)
Krankenversicherung (medical insurance)
Arbeitslosenversicherung (unemployment insurance)
Pflegeversicherung (nursing insurance)

Except for medical insurance these costs disappear without income, medical insurance is reduced to a nominal sum. The pension will be lower because of the missing years, but sometimes there were special laws waiving that deduction. Politicians used tax money to compensate, because it polished the unemployment numbers, expecting the lost job to be replaced by someone else.
Bob would also save some cost for no longer having to commute to work. And of cause have a lot more free time to do whatever.


How do I construct the eigenvectors of the Hadamard gate using Quantum Gates?

Question: How do I use quantum gates offered on IBM quantum to construct either eigenvector of the Hadamard gate?
Answer: Notice that the vectors you're trying to create are real. A great way of creating a real vector is to apply a $Y$ rotation,
$$
R_Y(\theta)|0\rangle=\cos\frac{\theta}{2}|0\rangle+\sin\frac{\theta}{2}|1\rangle.
$$
So, take the state you want to create and normalize it. For example,
$$
|\psi\rangle=\frac{1}{\sqrt{4+2\sqrt{2}}}((1+\sqrt{2})|0\rangle+|1\rangle).
$$
Now solve for $\theta$, i.e.
$$
\cos\frac{\theta}{2}=\frac{1+\sqrt{2}}{\sqrt{4+2\sqrt{2}}}.
$$
Thus, $\theta=\pi/4$. (If that's not so obvious, use the double angle formula,
$$
\cos\theta=\cos^2\frac{\theta}{2}-\sin^2\frac{\theta}{2}=\frac{(1+\sqrt{2})^2-1}{4+2\sqrt{2}}=\frac{1}{\sqrt{2}}.)
$$
Hence, the circuit you want to run is simply $R_Y(\pi/4)|0\rangle$. I'm assuming you can convert this into qiskit commands.


Usage of "cowardly" and "coward"

Question: I recently discovered that cowardly, which looks like an adverb, is actually also an adjective. So far so good. Then what is the difference between cowardly and coward, and is there any preferential usage of either?
Answer: The difference is that cowardly is usually an adjective, while coward is almost always a noun. Hence:

That dog is a coward.
  That cowardly dog runs at the sound of hooves.

In the rare cases that coward is an adjective, it is always prepositive (directly before the noun):

That coward dog just turned tail.

Not:

That dog is coward. (Coward is not prepositive - before the noun - hence this is wrong)

As to meaning differences (I've been dealing with usage), you would use cowardly if you weren't necessarily name-calling or venting; the term sounds more objective.  You could quietly use it, without strong feelings.  Coward, on the other hand, always connotes strong feelings.  If you use coward as an adjective, I'm more likely to think you are name-calling or venting.
Comment: Dictionary.com at http://dictionary.reference.com/browse/coward offers as an example: "a coward cry". This would seem to violate your rule that coward is never to be used before an action.
Comment: +1 @Fraser; I'm inclined to agree with you, though I still think it sounds more natural when used with a person or animal.  I don't think it's a rule.  I edited the answer.
Comment: In heraldry, "coward" is generally used as an adjective for a critter with its tail between its legs. In this context, "That dog is coward" is perfectly grammatical.
Comment: In modern usage, "coward" in "coward dog" would be a noun adjunct.
Answer: The "also" in the first sentence of the question suggests that "cowardly" can be an adverb as well as an adjective. I don't think this is true, or at least I can't think of an example. You can't properly say a guy fought cowardly. You'd say he fought like a coward. I'd actually like to use it, or any simple adverb, to mean "like a coward." (That's why I clicked on this post.) What are the alternatives? "Uncourageously" is too weak. "Pussillanimously" is the best I can come up with, but it would be weird if such a "big" word were the only adverb for such a basic concept.
Comment: It's the same issue that you face with adjectives like _friendly_, _miserly_, and _unruly_. There is no identical adverbial form in these particular instances, so if you aren't willing to adopt frilly adverbs like _friendlily_ (as some authors are), you either have to recast the sentence or choose a different adverb.
Comment: Could someone explain why my response was downvoted?
Comment: Hi, Yeltommo. I don't know what led someone to downvote your answer; I thought your position seemed reasonable enough. My guess is that either the downvoter felt that you hadn't provided enough documentation in support of your view or the downvoter disagreed with one of your factual assertions; it is always possible, however, that the downvoter was unhappy that the sky is blue instead of orange, in which case there is nothing you could do to satisfy him or her. Since I liked your original answer enough to comment on it, I will upvote it now; thanks for posting!
Comment: @SvenYargs Thanks. I wouldn't normally care, but "reputation" is actually valuable here. Your reputation suggests you know what's up, so perhaps you could explain why another answer of mine was not only downvoted but deleted. My guess is it had something to do with my post applying more directly to a comment than the original question, though I think it was still relevant to the latter. In any case, I don't understand why someone would (or indeed *can*) delete without explanation instead of challenging or at least deleting with explanation.
https://english.stackexchange.com/questions/119817
Comment: The deletion likely occurred because someone with unilateral deletion power or several people collectively felt that the answer was a response to a comment rather than a direct answer to the posted question. With a little editing, you can recast your response to minimize that problem. Instead of beginning it with "@JJB," consider starting with a wording along these lines:  "In a comment above, JJB says X. However, [or "Although this is generally true" or whatever suits the case] Y [rest of answer goes here]." If you can, tie the rest of your response explicitly to the original question.
Comment: @SvenYargs
Thanks much. I just realized that the reason I didn't write it as a comment is that you need a reputation of at least 50 to do so (excluding comments to your own answers). I find it bizarre that commenting requires a higher reputation than answering.

Usage of "cowardly" and "coward"


When to use a heatsink for a voltage regulator?

Question: Sometimes in small projects Im using voltage regulators with outputs 8V or 5V such as LM7805. Power is I*V but Im wondering when really a heatsink is needed. Sometimes the current flow from the regulator output is 1mA but in an other project 20mA or more. Is there a rule of thumb for when to concern about heating and considering to use a heatsink? Consider operating time is 12 hours.
Comment: If your current requirement is really up to 20 mA then you might want to consider using an [LM78L-series voltage regulator](http://www.ti.com/product/LM78L05) (that's an example of a datasheet for them).
Answer: Simple enough.
The part datasheet will specify thermal resistances. Looking at a LM7805 datasheet from Fairchild (just the first one to pop up in a search) thermal resistance is 5C/W junction to case, and 65C/W junction to air.
Max operating temperature is 125C. If the device is in a 25C environment, you can handle 100C rise (though some things fall off at Max Operating Temperature, typically) so about 1.5W (100C/65C/W) will be all you can dissipate without a heat sink. If your input supply is 30V, that's perhaps 60mA; if the input is 12V it's more like 214 mA; if your input is 8V, it's 500mA. (All at 25C ambient.)
Working the example the other direction, your comment indicates a 24V supply and a dissipation of 0.38W; 0.38W * 65 C/W = 24.7 C, so you can run that up to an ambient of 100.3 C without a heatsink.
EDIT: In all of the above I have evidently neglected the regulator's own current use of 5.5-6mA (at full input voltage), located a long way down the datasheet, which adds to the power load; in your 24V example this would lower your ambient safe range to about 90 C
When you add a heat sink, you will have the 5C/W junction to case (thermal resistance) plus a certain amount of thermal resistance from the case to the heatsink (influenced by thermal grease, insulators or not, etc.) and finally the heatsink's more favorable resistance to air.
So if the interface is 2C/W and the heatsink is 10C/W, you'd have a total of 5+2+10=17C/W from junction to air with interface and heatsink.
With the 7805 having a grounded case/tab, it's easy to bolt it to the side of a metal case/chassis for some "free heatsinking" if desired. When prototyping, if using parts with thermal overload protection (which is claimed but not fleshed out in the datasheet) you can "just see if the part gets hot and shuts down" though you should run the numbers before finalizing the design, especially since prototypes often have better natural convection than a finished product.
Comment: Imagine input voltage is 24V and output is 5V and the input current is 20mA.. So the power = voltage-difference * current = V*I = (24-5)*0.02A = 0.38W. Since this is less than 1.5W there is no need for a heatsink?? Did I understand you correct?
Comment: ...1.5W is dependent on the air temperature the device is exposed to being 25C. Yes, you should be fine without a heat sink up to 100C ambient if you are only dissipating 0.38W (which causes a temperature rise of 24.7C)
Comment: should the case tab of a heatsink grounded? if so do u mean circuit gnd or earth gnd?
Comment: It's an engineering decision. For a part like 7805 the tab IS at circuit ground, so it's easy to deal with. For items with hot tabs, you either need an insulator (which adds to the thermal resistance) or you have a hot heatsink (which is a shock hazard when working on the live circuit, and also a mounting/hardware issue to keep it isolated from the case.)
Answer: My personal rule of thumb is that a TO-220 3-terminal linear regulator does not need a heatsink for less than 600mW (vertical mount). That's based on industrial service and high reliability so it's a conservative number.
If it needs to be more than that then I do the calculations, and possibly even tests, and decide what's best.
You can do a moderate copper pour and use a (surface mount) TO-252 and get better thermal performance than a TO-220 without a heatsink - often quoted at 65°C/W in air. That costs nothing except a bit of PCB area- no fasteners, assembly labor or heat sink costs to consider, no extra (secondary) operations and extra ways for assembly workers to screw things up.

In my opinion, if you're close to needing a heat sink for a linear regulator it's time to at least consider a switching supply unless you have special requirements such as low EMI.
Answer: Simple Example
E.g. https://www.fairchildsemi.com/datasheets/lm/LM7805.pdf

Calculate the power dissipation in the LDO.  E.g. 8V to 5V at 100 mA is 0.3 W (voltage difference times the average current).
Calculate the temperature rise to air (no heatsink): 65 °C/W * 0.3 W = 20 °C
Look at the worst ambient operating temperature: e.g. ~ 40 °C
The max case temperature will be 40 °C + 20 °C = 60 °C, which is below the max operating temperature.

Notice that this temp rise is quite small for this very small voltage drop.  That's why a heatsink is typically recommended for heavier currents or larger voltage drops.  I'd say that maybe 10% of LDO's that I have seen in total have a heatsink.
But:

Heatsink is an additional component and increases the BOM cost.
It's heavy and needs to be mounted properly to absorb mechanical shock during operation or transportation
Answer: The power dissipated is the voltage drop i.e. Input voltage - output voltage * the input current.
The data sheet will state the maximum junction temperature, and a thermal resistance to the case in °C / W This will be the temperature rise from ambient (so if you are operating in the tropics you have a higher ambient) if the device is in free air without a heat-sink
Provided the calculations give a junction temperature less than max, you don't need a heat-sink
Operating time is not usually an issue - unless your application will only operate for a few seconds, when the thermal lag will lead to a lower rise at the junction.


When a web site asks for my "PayPal account", is it just the email address I use with PayPal?

Question: I just created a PayPal account because I want to get registered on a web site requiring PayPal. In the registration form on that site there is one field to be filled in: "PayPal account", but I don't really know what exactly I am supposed to type in there. Should it be my email address that I gave PayPal while I was registering there (letters from PayPal come to this e-mail box of mine), or should it be something else?
Comment: @duffbeer703 I think this question is fine.  It's more a "money" question than a "finance" one.  But, questions about online payment systems like PayPal, which can be used by individuals, are on-topic.
Comment: @Chris W. Rea: Thank You very much for editing my question. I just didn't know how to put it into words properly.
Answer: Unless you intend to buy things from that website, that website has no business asking for 'your paypal account'.
Either they've got malicious intent, or they just want an email address and are painfully unaware of how infosec works and in either case I would not recommend giving them anything pertaining to your financial information.
Comment: Actually, the only valid reason for asking for "your PayPal account" is if they want to send money TO you. If they want you to pay for something, they should instead redirect you to the PayPal website to sign in and confirm the payment there. The whole point of PayPal is that (unlike card payments) the merchant never sees your payment credentials at all.
Answer: Yes, your email address is your "PayPal" account. It's what people use to send you money, and what you use to pay people.
Answer: Id meber
2
Yes, your email address is your "PayPal" account. It's what people use to send you money, and what you use to pay people.


On windows 10, how do I setup a VPN client so that all users can use it (i.e. available before login)

Question: On Windows XP, 7, 8, 8.1 you could tick a box that says 'Allow other users to use this VPN' when you initially connected the VPN.
This option is no longer available - how do I set the VPN to be available for connection on the Login screen?
Answer: Old question but for anyone trying to find an answer there is a better solution via elevated powershell:
Add-VpnConnection -Name MY_VPN_NAME -ServerAddress MY_VPN_SERVER -AllUserConnection $true -SplitTunneling $true -AuthenticationMethod MSChapv2 -TunnelType Automatic -EncryptionLevel Required -PassThru

Source
Comment: Maybe a change since this answer but I had to remove both $true variables as it was not recognised
Answer: CrayFishUK, my experience for all Windows XP/Vista/7/2008/8/2012/10 This will connect VPN as a SYSTEM user when system starts.

You will need to create a VPN connection
Save or not save credential it is not important.
Find a rasphone.pbk in %APPDATA%\Microsoft\Network\Connections\Pbk_hiddenPbk
More nice if you will copy it to C:\ProgramData\Microsoft\Network\Connections\Pbk\rasphone.pbk or
  attach to exist rasphone.pbk (it is text files)
Now you need to create scheduler task...

Scheduler task:

Start after boot
Program to start has credential to connect VPN

Code:
cmd /c rasdial VPNUSER VPNPASSWORD /PHONEBOOK:"C:\ProgramData\Microsoft\Network\Connections\Pbk\rasphone.pbk" && route add 10.0.0.0/8 172.16.0.254

You will need change the creator user to the SYSTEM user

I have add at the end:
route add 10.0.0.0/8 172.16.0.254

for exampe, how to auto add route when sucsesful connect VPN

If you will need to reconnect VPN when it fails ask a new question and
  I will help.
By default VPN send all traffic through VPN, if you want to use routes You will need to turn off this future.
Answer: A VPN config is stored as text in rasphone.pbk. The all-user copy of rasphone.pbk is located in the "all users" profile: on win11 pro the default is
c:\users\all users\microsoft\network\connections\pbk\rasphone.pbk

There are many ways you can add to or modify a text file. You can copy rasphone.pbk from your admin profile. You can copy and append from a text file: You can use WMI (or any Web-Based Enterprise Management controller), or RAS.exe or powershell -- which is a shell for things like RAS and WMI.
EAP data is stored as a blob in the file (CustomAuthData) Credentials are stored separately: the GUID referenced in the config file is used as a key to HKEY_LOCAL_MACHINE\Security\Cache. If you use certificate, make sure that it is stored in a store that the user has access to.
Rasphone.pbk is not "a vpn". It is a "phone book".  When you put your phone book entries in the global phone book, windows can see them before login.
Answer: You CAN still setup a VPN for all users on Win10 and Win11 and you CAN still setup a VPN that to connect to a network (Network Sign in) before you login through the GUI. Microsoft have just made the interface a bit more convulted to get to it.
Click Start, then type Control Panel.
Click the Network and Internet heading, then select the Network and Sharing Centre heading.
Then select the Setup a Connection or Network.
Choose the option  Connect to a workplace.
Create a new connection, choose Use my Internet Connect (VPN), then add in the details (i.e. VPN server IP address or host name, and a name for the connection).
Make sure you tick the option, Allow other people to use this connection.


Entering simple and grouped products

Question: Will the layout be the same for each product being entered, if it's just simple only or if I add grouped as well. I may down the road have more so would it be better to always do grouped too and simple for each one that I enter? Also is it better to add simple first then go back to grouped after you have completed the simple products?
Answer: You need to add first simple products and then select all them in a grouped products. But yes you can add more products in group product according to your need.

Entering simple and grouped products


When's the best time to fly with kids

Question: I'm about to take my son on a trip overseas, should I book a early morning flight or book a afternoon flight ? Taking in the time difference we would arrive at his bed time if we took afternoon flight
Comment: Many fliers would say that the best time to travel with children is after their 10th birthday.
Comment: It seems like this would depend greatly on your son's specific routines and temperament; I don't know that there will be any general answers.  That said, you might also ask on Parenting.SE.
Comment: Best in what sense?
Comment: Best for what? Also it would depend on where you are flying and the time zone and travel times.
Comment: Speaking as someone with three toddler nieces/nephews scattered on both coasts, it certainly depends on the child.
Comment: I would have said 18th, but 10 works too.
Comment: Tough question!  We usually settle on **day** flights, and just accept that you have to spend the total time, every minute, being with the little tykes and entertaining them.  (Older kids just play with an ipad, of course.)
Answer: For small babies (up to 6-7 months):
Any time of the day will work. Babies sleep a lot at this time, and if they will sleep on the plane, they will. Usually feeding/nursing a young baby to sleep on the plane is the best way to go.
For older babies and young toddlers (7 months- 1.5 years):
Redeyes usually work the best I found. At this age it is very hard to entertain the babies on the plane, especially after they learn to crawl and walk. They will want to MOVE. If you can go at their regular night time, it is easier regardless of the trouble with jet lag after you arrive.
Over 1 year I would personally recommend a ticket and a carseat approved by the airline for longer flights, even if you can have a kid on your lap up till 2 years.
For older toddlers (1.5 years- 4 years)
Here personality comes more into play. How easily is he entertained by something like an iPad? For us, we found that leaving locally in the afternoon, but skipping the mid day nap is the easiest. They feed you on the plane, and the kid has an early night. when going East this means you arrive close to evening time, but travel wears you out, and he just stayed up a couple of extra hours.
If you kid is easily entertained when sitting still, it may be better to go during day if you can sleep when you arrive.
In addition, note that most kids are really excited about the plane and the airport and everything at first, so it may take a little while to calm down to sleep.
For older kids (4-5 years and more)
In my experience kids this age usually does pretty well watching movies for an entire 8-10 hour flight, and are able to sit mostly still for a long time. Unless you have a very active kid, you should probably pick whatever is best depending on arrival time.

Of course all of this does depends heavily on the kid's personality. Is he very calm? Is he afraid of flying? Does she fall asleep easily in new places? Is she easy to handle when a little tired (as a result of jetlag)? It also depends on you. If you take a redeye and your kid doesn't sleep, are you able to function?
Comment: You know a handy tip when with lots of small children. If you don't live right near the airport, consider splashing out on bookend hotel rooms. So you can all have a great night's sleep and adventure, and then get on the plane refreshed.

When's the best time to fly with kids


How to export a bks keystore on Debian 7.9 wheezy

Question: I need to generate a keystore.bks file to use for android development. I cannot figure out how to export a bks keystore without using a GUI tool. I have server space on Google Compute Engine which I am connecting to through SSH. There is no GUI option that I know of.
I set up HTTPS on Tomcat doing the following:
<code>Run $JAVA_HOME/bin/keytool -genkey -alias tomcat -keyalg RSA
You will have to answer a few questions. Most are intuitive. But:
Specify same passwords for both: key store and key.
After completion you will have new key store with new key.
As the next step you must edit $CATALINA_BASE/conf/server.xml file: Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol" maxThreads="150" SSLEnabled="true" scheme="https" secure="true" clientAuth="false" sslProtocol="TLS" keystorePass="your_password_from_step_3" />
</code>
I did that stuff; now I need to export my keystore as keystore.bks and I cannot find a way to do it -- at least not something I can understand. I am extremely new to Linux and really need it to be spelled out; 1. download using this command "blah blah blah" 2. run this command "blah blah blah". Sorry for being inept, but I am very much struggling to accomplish something I think is probably relatively straightforward.
These are the instructions I was given:

Go to http://portecle.sourceforge.net/ and download Portecle
Open your JKS keystore via Portecle
Export your certificate
Create new BKS keystore
Import your certificate and save BKS keystore as "keystore.bks"
In android app replace keystore.bks file by your just created BKS keystore
In app.properties modify "server.ssl.keystore_password" as you need

Unfortunately I cannot execute portecle in my Linux install because it does not have a GUI. I tried to load the installer to the server and run java -jar portecle.jar and it failed:

Dec 19, 2015 2:33:37 AM java.util.prefs.FileSystemPreferences$1 run
  INFO:  Created user preferences directory. Exception in thread
  "AWT-EventQueue-0" java.awt.HeadlessException: No X11 DISPLAY variable
  was set, but this program performed an operation which requires it. at
  java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:204)
  at java.awt.Window.(Window.java:536) at
  java.awt.Frame.(Frame.java:420) at java.awt.Frame.(Frame.java:385) at
  javax.swing.JFrame.(JFrame.java:189) at
  net.sf.portecle.FPortecle.(FPortecle.java:342) at
  net.sf.portecle.FPortecle$CreateAndShowGui.run(FPortecle.java:6537) at
  java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) at
  java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) at
  java.awt.EventQueue.access$500(EventQueue.java:97) at
  java.awt.EventQueue$3.run(EventQueue.java:709) at
  java.awt.EventQueue$3.run(EventQueue.java:703) at
  java.security.AccessController.doPrivileged(Native Method) at
  java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
  at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) at
  java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
  at
  java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
  at
  java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
  at
  java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
  at
  java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
  at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Answer: From Tomcat's How-To:

$JAVA_HOME/bin/keytool -genkey -alias tomcat -keyalg RSA
This command will create a new file, in the home directory of the user
under which you run it, named ".keystore".

Thus, keystore is just a file. So, you can download it onto your local machine. If you use Windows, you can use FileZilla for this purpose. And then you will be able perform necessary manipulations locally.


The Cryolator disappears after using the Dogmeat glitch

Question: Inside Vault 111, I asked Dogmeat to fetch items near where the Cryolator is stored. However, when Dogmeat retrieves the Cryolator, it disappears when he drops it. Is the Cryolator lost, or can I still get it somehow?
Answer: This was a reported bug, as of patch 1.34. If you used the glitch on console, and the gun glitched out, I'm afraid it's gone. If you happen to be playing on PC, you might consider using console commands to give yourself one, instead.

Bugs

Dogmeat can no longer be ordered to get the weapon after the 1.34 update. Doing so will glitch the game and Dogmeat will either grab a pipe gun or a combat shotgun and sometimes nothing and the Cryolator will disappear. [verified]
- "Cryolator (Fallout 4) @ Fallout Fandom

Roddy of the Frozen Peas reports that, at least as of 11/7/2020, you can't physically take Dogmeat into Vault 111. This was likely patched in to prevent both the original exploit, and the resulting glitch that occurred past patch 1.34.

Obtaining the Cryonator

You can open the container, yourself, once you gain rank 3 in the Locksmith perk. This perk requires 4 perception, a player level of 18, and the two preceding Locksmith perks before being unlocked.
If you have Cait as a companion, she can pick the lock. You may need to give her a number of bobby pins for her to open the lock.
If you have the "Automatron" addon, you can upgrade robot companions with a lockpick module, which gives them the same lockpicking ability as Cait. The lockpick module requires 4 adhesive, 2 aluminium, 1 ceramic, 2 circuitry and 3 rubber and must be crafted from a robot workbench.
If you are playing the game on PC (and not in Survival mode), you can just give yourself the gun via console commands. Press the ~ button to bring up the console, and enter the command player.addItem 00171B2B 1. This should add one Cryolator to your inventory. You will likely also need ammo, which you can add with player.additem 0018ABE2 X. Replace X with how every many cryo cells you want.
Answer: Get Dogmeat to grab it then leave the vault before he has time to give it to you then it'll be in his inventory. I don't know if they tried to patch it or what but it used to work but I haven't played in 2 years.
Comment: The Dogmeat Cryolator glitch has been patched for years. You can't take him into Vault 111 anymore. (Source: I just tried it about 2 hours ago.)
Answer: Don't use Dogmeat I tried this once and he will grab a pipe pistol or a shotgun but will never grab the cryolator. To fix this leave him in Sanctuary and go to Combat Zone and get Cait and give her all your lockpicks you might have to use the Lockpick cheat but she will open the safe and you can get it.


Which Hindu texts contains the story of Santoshi Mata and about her other legends?

Question: I checked wikipedia and according to it there is no scriptual reference of Santoshi Mata in Hindu texts and she just gained popularity after 1960 movie 'Jai Santoshi Maa'. After reading the wiki article it seems as if she is a self created new goddess. Can somebody please explain which hindu texts contains the story of Santoshi Mata and about her other legends ?
Comment: Yes, it is true that there is absolutely no record of Santhoshi Maa before the 1960's, and then she was popularized by the 1975 movie.
Comment: @Vipul Actually Santhoshi Mata was worshipped for 15 years before the movie was made, although the movie is what popularized her. But yeah, there's no record of her before the 1960's.
Comment: No, Santoshi Mata is not Hindu goddess. She is just production of a movie for sure. The movie was released on Friday so woman used to fast on Friday :) it is really funny but it is really true.
Answer: This is a clear indication that Kaliyuga incarnations of God are available today to fight the necessary evils on earth. Such an incarnation of supreme valour is Maa Santoshi. That's why, learned persons only recommend understanding, reading mainly SRIMAD BHAGWAD GITA, as it's the essence of all other Scriptures.
In BHAGWAD GITA, Krishna doesn't mention any Goddess name at all, he simply mentioned once that-
Among women I am fame, fortune, speech, memory, intelligence, faithfulness and patience.

मृत्युः सर्वहरश्चाहमुद्भवश्च भविष्यताम्।
कीर्तिः श्रीर्वाक्च नारीणां स्मृतिर्मेधा धृतिः क्षमा।।10.34।।
I am the Death that carries away all and also the Birth of all that
are to be born; among women, I am the Fame, Fortune, Speech,
Memory, Wisdom, Constancy and Patience.

Here, women denotes-- DEVI MAA
Here,
Patience-- denotes 'Santosh'- one of the qualities MAA SANTOSHI bestows on her devotees.
Other Goddess too can be observed in the above verse--
Speech- bestowed by MAA SARASWATI
Fortune- bestowed by MAA LAKSHMI
Fame(power,status)- bestowed by MAA KALIKA
Also, Sri Krishna tells among all intonations mantra, he is the Gayatri mantra.
Comment: You have to quote references for the answers provided in this site.  In respect of this answer, I have provided the reference.  By the way, the Gita sloka, which you are referring to may not be answering the question.  Please check again.
Comment: SRIMAD BHAGWAD GITA is the only authentic eternal knowledge source- as it's God gifted - (latest Sri krishna revived this eternal knowledge to Arjuna and was passed down as it is through succession of saints) while other innumerable sources are outcomes of meditations, thus, created by saints based on their level of expertise.
Comment: There's no mention of any Santoshi word even, let alone Devi Santoshi. This is not an answer.
Comment: She's present time necessity accepting worship 'Kaliyuga avtar' as based on necessity God's descend for example Rajasthan has many Kaliyuga avtar of God's like: Ramdev Pir https://www.google.com/amp/s/www.patrika.com/jaisalmer-news/history-of-baba-ramdev-ji-peero-ka-peer-3410460/%3famp=1 ;
 He's our savior and present Vishnuji along with Tirupati Balaji in South https://en.m.wikipedia.org/wiki/Ramdev_Pir
Comment: @SaurabhTJain Ramsa pir being avataar of Vishnu is found only in
the bhajans sung by Harji bhati, Rawal maal, Tolla de
& Rani Rupa de. Other than that I doubt if there is any mention of him being Dwarkadhish himself by other contemporary saints of that time. Incase if you have more ref to it, please attach the link in comment, tht will be alot helpfull.
Comment: https://en.m.wikipedia.org/wiki/Ramdev_Pir


Changing the color in XFCE themes

Question: Why in XFCE you can change the color of themes like Greybird, but when you try to do that for Clearlooks-Phenix the color does not apply in some applications?
Comment: Are you just looking for an explanation or a solution?
Comment: Explanation, but a solution would give some insight on what is going on.
Answer: The gtk3 part of Clearlooks-Phenix does not work with applications that change the colour of the theme. Applications that were updated to gtk3 won't have the selected colour.
To complete change the colour of Clearlooks-Phenix is necessary to edit the colours in gtk-variant.css and in the images located at the img folder.
Answer: First of all, clearlooks-phenix github page has already noted in the README.md that you should download and install appropriate version of the theme.
GTK version compatibility
The main reason is, for the theme to be applied correctly, you must use the theme that supports particular version of GTK toolkit in use.

Download the appropriate version according to your situation:

for GTK 3.0 and 3.2: download Clearlooks-Phénix v1;
for GTK 3.4: download Clearlooks-Phénix v2;
for GTK 3.6: download Clearlooks-Phénix v3;
for GTK 3.8: download Clearlooks-Phénix v4;
for GTK 3.10 and 3.12: download Clearlooks-Phénix v5;
for GTK 3.14: download Clearlooks-Phénix v6.

To find your GTK version:

You can check in your package manager the version of the package libgtk-3-0.
If you use Ubuntu, here's a correspondence between its versions and those of GTK (for a default installation of Ubuntu):

Ubuntu 11.10: GTK 3.2
Ubuntu 12.04: GTK 3.4
Ubuntu 12.10 and 13.04: GTK 3.6
Ubuntu 13.10: GTK 3.8
Ubuntu 14.04: GTK 3.10
Ubuntu 14.10: GTK 3.12

For example, if your host system is running Ubuntu 14.04 (shipped with GTK 3.10), you should download and install Clearlooks-Phénix v5.
GTK support by theme

Why in XFCE you can change the color of themes like Greybird, but when you try to do that for Clearlooks-Phenix the color does not apply in some applications?

Greybird is part of Shimmer Project, that incorporates themes for Xfce. It is also the default theme for the Linux distribution, Xubuntu. The preinstalled applications are usually the most compatible with the default theme, because these have been matched with appropriate GTK version already.
That's why those "some applications" might be using different GTK toolkit version than the rest. Even you upgrade the GTK toolkit version on your system, not every applications in the repository is updated enough to cope with the latest themes.
Even among the themes created under the same project, Greybird has better support for both GTK 2 and GTK 3 when compared to older themes like Bluebird or Albatross. I know this, because I have already experienced with these default themes on Xubuntu 12.04 and 14.04.

Changing the color in XFCE themes


Web based BIND9 DNS tools?

Question: Are there any good front end tools to manage a BIND9 server? I'd like to offer users the ability to have a login and manage their hosted zones.
Answer: it's simple http://sourceforge.net/projects/smbind/
Answer: While not technically for BIND you should check out https://www.poweradmin.org/trac/.
Poweradmin is a front end for power DNS which can run a bind compatible backend.
http://doc.powerdns.com/
Comment: While I personally hate Bind9 and avoid it like the plague,  -- I've seen this tool used with success in the past.
Answer: If you're looking for commercial options, I can suggest Plesk for this - but that may be overkill. It will allow you to set up users and give them a nice interface for managing their Bind zones.
Other than that, I think Webmin allows this feature, as well as some of the other open source hosting control panels.
Comment: Thanks. I looked into those options but everything I've tried seems to be slightly overkill (as you mentioned). What I need to find is a PHP class for BIND9 that I can extend/customize the way I want.
Answer: I use Webmin for my Bind adjustments.
Here is a guide to installing Webmin on Ubuntu 10.10 - Webmin How-to Install Ubuntu 10.10

Web based BIND9 DNS tools?


Can you please add other folders back to sync options back to Ubuntu One in Windows?

Question: Upgraded from the beta client to release 2 and now find that my old folders on my d: drive can no longer be added, only folders under my c:/docs and settings/user. I have a separate drive for data and this is where my documents resides.
Answer: I think you are talking about Ubuntu One on Windows.
You could try to create a Juction (a NTFS symbolic link) inside your User folder, that point to folder in D:. Here you can download the Junction utility:
http://technet.microsoft.com/en-us/sysinternals/bb896768
I have not tried it, but may work.
Comment: Thanks. I have come up with a few work around,s, but I really liked the way the beta worked and was hoping it would not change as drastically.


How to measure temperature with a barometer?

Question: I know how to use a thermometer to determine the pressure (the Clapeyron-Clausius equation) or to conduct an experiment with heating water to a boil, and look at the table of the dependence of the boiling point on the pressure, but how to use a barometer to determine the temperature?
Answer: The density of mercury will change with an increase or decrease in temperature, so reading must be adjusted for the temperature of the instrument. For this purpose, a mercury thermometer is usually mounted on the instrument. Temperature compensation of an aneroid barometer is accomplished by including a bi-metal element in the mechanical linkages. Aneroid barometers sold for domestic use typically have no compensation under the assumption that they will be used within a controlled room temperature range.


AS3 Air for Android [Error 2070] - Remotely loaded SWF cannot access Stage from App

Question: I am building an Air for Android (AS3) application that will load remote swf files (located on my server)
The idea is to keep the apk as stream lined as possible to allow fast deployment (will be deployed privately and not over Google Play)

The apk is called the Loader
The remote swf is called the Player.

Now, Player is throwing up this error when I launch Loader:

SecurityError: Error #2070: Security sandbox violation: caller http://sub.mydomain.com/remote/player.swf cannot access Stage owned by app:/Loader.swf.

This is odd as Player does not try to call the Loader stage - I told Player to make a new stage called "_stage", code below:
var playerContainer:MovieClip = new MovieClip();
var _stage:Stage = playerContainer.stage;

Using:
_stage.stageWidth

to access the stage width.
I have no idea why Loader thinks Player is trying to access it's stage properties?
I have tried the following pieces of code that I have seen mentioned in various forum posts, but nothing seems to alleviate the problem with the security domains:
In Loader
try {Security.allowDomain("*");}catch (e) { };

In Player
Security.allowDomain("http://sub.mydomain.com");

and also in Player, for my init() function
addEventListener(Event.ADDED_TO_STAGE, displayLogin);

Neither of these help.
I am at a total loss. It's above my head as to how to get Loader to allow Player access to its stage properties.
EDIT - when both swf files are on the server, and I access Loader via a browser, rather then using the android app, it loads fine. Definitely an issue with cross scripting, but it looks to me like I have all the right code to allow that?
Answer: Pablo,
first if it adds item to the stage than it access the stage property, maybe you should download the player.swf to SDCard or apps local storage and loaded it from there? You could then set expire date after which you will reload the player.swf?
Here is the link to other SO Question about storing remote file on SDCARD
Comment: Could you point me in the direction of how to go about downloading the player to local storage and embedding that instead of the remote file?