how to recover data from a logically corrupted external hard drive using testdisk
How to recover data from a USB-connected hard disk that shows no partition?
How to know if a time series is stationary or non-stationary? How can I use multiple accounts with Telegram? Is there a way to have two copies of  app in Ubuntu each with a different account?  It seems copying the app in another folder does not work. Why is ATP the most prevalent form of chemical energy storage and utilization in most cells? I am running a fresh install of Linux Mint Nadia (14). I am following the instructions on Vagrant  but have gotten stuck on the . It seems the Vagrant box cannot connect outside and so I can't install anything using either Chef or Puppet.  In the basic Vagrant resolve.conf contains nameserver 10.0.2.3. But with that set I can't ping us.archive.ubuntu.com.  If I change it to 8.8.8.8 then I can ping us.archive.ubuntu.com but it does not stay set, and after a reboot it changes back to 10.0.2.3 - so provisioning fails again.  Ideally I would like for 10.0.2.3 to work on my setup. Failing that I would like a way to permanently change resolv.conf so that I can do provisioning. Why prefer the 18-55mm and 55-250mm lenses vs 18-200mm? Where can I find good literature for beginners? I am trying to find some database tutorials,books and similar, since I have started this course in college, and received some material, but it is really hard to manage through all the info on the net. I searched through the questions on the site but didn't find any. Thankfull for all your input. bash: syntax error near unexpected token `}' Which manga chapters correspond to the 2nd season (or "Season 3" on Netflix) of the anime, "Revival of the Commandments"? The 2nd season (labeled as "Season 3" on Netflix) of the anime, Nanatsu no Taizai: Imashime no Fukkatsu (or The Seven Deadly Sins: Revival of The Commandments), has ended.  Which manga chapters correspond to each of the anime episodes? My girlfriend forgot the password for her MacBook (don't ask), so I reset it using the Utilities.  But as you may be aware, this doesn't reset the Keychain password. Her MacBook is now virtually unusable due to Keychain demands continuously provoking a request for the Keychain password.  There are lots of other people asking this around the web and they're usually pointed towards this , which doesn't apply in our situation because the support advice involves entering the old password.  We don't know the old password.  Is it possible to reset Keychain without knowing the old password? We're not bothered about what's in there and what will be lost, we just want the continuous password prompts to go away. T-SQL: Selecting Column Based on MAX(Other Column) How to calculate overlap between empirical probability densities? I'm looking for a method to calculate the area of overlap between two kernel density estimates in R, as a measure of similarity between two samples. To clarify, in the following example, I would need to quantify the area of the purplish overlapping region:  library(ggplot2) set.seed(1234) d &lt;- data.frame(variable=c(rep("a", 50), rep("b", 30)), value=c(rnorm(50), runif(30, 0, 3))) ggplot(d, aes(value, fill=variable)) + geom_density(alpha=.4, color=NA)     A similar question was discussed , the difference being that I need to do this for arbitrary empirical data rather than predefined normal distributions. The overlap package addresses this question, but apparently only for timestamp data, which doesn't work for me. The Bray-Curtis index (as implemented in vegan package's vegdist(method="bray") function) also seems relevant but again for somewhat different data.  I'm interested in both the theoretical approach and the R functions I might employ to implement it. In my book, the following are described to be the steps that one must follow if he wishes to find the direction of static friction force acting on an object:  &quot;(1) Draw the F.B.D(free body diagram) of the object in question with respect to the other object on which it is kept. (2) Include the pseudo force also, if the contact surface is accelerating. (3) Decide the direction of the resultant force and resolve this force into two components; one along the surface of contact and the other along the normal to this surface. (4) The direction of static friction is opposite to the component of the result force along the contact surface.&quot;  Firstly, are these steps correct? Will I always obtain the correct answer by following these steps? Secondly, consider the following problem:  In questions like these, when I try to find the resultant force and then assign the direction to static friction, I find that my answer is incorrect! Are there some other steps to follow when I know that the object is definitely accelerating in one direction or another? Edit 1: I approached the above question by doing exactly what my book suggests; first, I identified all the forces acting on the smaller block, being the normal force applied by the block A and its weight mg downward. Adding these two forces, I get another force that actually acts on the body like so:  I wonder if I'm not supposed to take either of the contact forces into consideration when drawing the F.B.D to figure out the direction of static friction acting on the body. Also, are there other steps for finding the direction of kinetic friction? Edit 2: From Judge's answer, I have been able to figure out my mistake, it being that I completely missed step (3) and didn't resolve the resultant force into components! Sheesh. Sorry! Much thanks in advance! :) Regards. The identity cannot be a commutator in a Banach algebra? The Wikipedia article on  claims, without a proof or reference, that there does not exist a (unital) Banach algebra $B$ and elements $x, y \in B$ such that $xy - yx = 1$. This is surprising to me, but maybe the proof is straightforward; anyone have a proof and/or a reference?   More generally, I would have naively thought that I could embed any ring into a Banach algebra. I guess there are actually serious restrictions to doing this; are these issues discussed anywhere? When I type $\overset{\circ}{Z}^\lambda$ the lambda is placed slightly above and to the right of the circle. Is there a way to make it appear as a superscript on the Z? I tried $\overset{\circ}{Z^\lambda}$, but then the circle is too high and to the right.  As a bizarre aside: a friend uses the exact same code with no problem. However, when I type it into MathOverflow it looks the same as in my compiler (i.e. bad). $\displaystyle\int_0^0\frac 1x\:dx$ This integral is defined ? If it define, what is the value ?  Please,step by step Isomorphism equivalence implies fundamental group is abelian As many people already know, there are several ways to trigger Windows 7 Aero Snap feature. A user can either press Win+{Left,Right,Up,Down} to snap the window to the left or right or maximize or restore. One can also drag the title bar to all the corner except bottom one.  However, is there any keyboard or mouse shortcut to place one window on top half the screen, and another window on bottom half the screen? Please do not tell me to use "Show Windows Stacked" because if I have more than two windows, it will place ALL the windows horizontally, which is not what I want. I want to be able to select the window I want and place it automatically either on top or bottom half the screen.  Thanks!  Edit: Thanks for Moab's suggestion, both on recommend WinSplit and updating my question.  I should make it more clear that I'm looking for a software that will do the functions WinSplit provided, but with on screen input, such as touch screen or pen. SQL Server Query Plan Hash Collision I'm wondering if anyone can shed light on a worry of mine that a query_plan_hash collision could cause a query to be executed as an entirely different query.  The hash is a 16 digit Hex that sp_help sys.dm_exec_query_stats says is a binary. Therefore it's only a 64 bit hash, and a collision seems very probable (considering SHA1 [160 bit] was just verified to have had collisions).  Would the plan_hash and the query_plan_hash both have to collide for this (query to be executed as an entirely different query) to happen?  I'm also curious if there is a setting somewhere in SQL Server that will allow us to change this hash to SHA2-512 (to reduce the possibility of a collision). Our data is very important.  I searched high and low via Google and Stack Exchange forums. Why does the buffer take up whole screen? I am trying to create buffers around the Hurricane Sandy path I created in QGIS (points are lat/long).   I have both points from each day she was tracted and the line I created from it with Points2One.   When I go to make buffers around either the line or the points, the buffer takes up the whole screen. Its all just one color.   I have made buffers before but from data I did not create.   Right now all of my projections are set to WGS 84 EPSG 4326. I would like to know if there is any way to add custom behaviour to the auto property get/set methods.  An obvious case I can think of is wanting every set property method to call on any PropertyChanged event handlers as part of a System.ComponentModel.INotifyPropertyChanged implementation.  This would allow a class to have numerous properties that can be observed, where each property is defined using auto property syntax.  Basically I'm wondering if there is anything similar to either a get/set template or post get/set hook with class scope.  (I know the same end functionality can easily be achieved in slightly more verbose ways - I just hate duplication of a pattern)