Does heat sink of laptop contain any coolant? Heat sink of a laptop consists of copper tube. It is used to cool the processor and other electronics. Does the tube contain any coolant or it is just air filled?
CPU cooler does not fit, will it cool worse if I cut tips of heatpipes off? Case: zalman z9 neo  Cooler: deepcool gammaxx 400  According to specs it should fit, but it does not, probably because my motherboard is mini-itx and cooler located a bit to the left  I'm thinking that cutting off those tips of heatpipes on the left would solve that; if I do that, will cooler work worse, like heatpipes would transfer heat not as good or something?
How can I change the umask for one command only? How can I interactively execute a command in Linux (zsh, if it matters) with a different umask from the default, for one command only? Perhaps a combination of commands combined in a single line? The new umask should apply only to that command and return to its default value for the next command entered.  Ideally the command would be agnostic to the default umask in force before its entered (in other words, the default umask doesn't have to specified). My question relates to Chapter 3, Exercise 8 in &quot;Baby Rudin&quot;. It states: If $\sum_n a_n$ converges, and if $\{b_n\}$ is monotonic and bounded, prove that $\sum_n a_n b_n$ converges. My attempt would have been: Since $\{b_n\}$ is monotonic and bounded, $\{b_n\}$ converges and it exists $\inf \{b_n\}$ as well as $\sup \{b_n\}$. But then we have $$ \left| \sum_n a_n \inf \{b_n\} \right| \leq \left| \sum_n a_n b_n \right| \leq  \left| \sum_n a_n \sup \{b_n\} \right| \leq \max \left( \left| \sup \{b_n\} \right|, \left| \inf \{b_n \} \right| \right)\varepsilon \leq \tilde{\varepsilon} $$ since $\sum_n a_n$ converges and $\max \left( \left| \sup \{b_n\} \right|, \left| \inf \{b_n \} \right| \right)$ is a finite number. This would imply, by the comparison test, that $\sum_n a_n b_n$ converges as well. $\quad \Box$ But as there was a way longer, more rigorous proof chosen in this , I'm a bit suspicious that my proof is not complete. Am I missing something?  EDIT: Thanks everyone! @hermes: The last part of your proof gave me the following idea. As $\lim_{n \to \infty} b_n = c$ and $\{b_n\}$ is monotonic, couldn't we just set $b_n = c - c_n$ with a monotonically decreasing sequence $\{c_n\}$ which has $\lim_{n \to \infty} c_n = 0$. Then we have $$\sum_n a_n b_n = \underbrace{c \sum_n a_n}_{\text{converges by assumption}} - \underbrace{\sum_n a_n c_n}_{\text{converges by Theorem 3.42}} \leq \varepsilon_1 - \varepsilon_2 = \varepsilon $$ since  Theorem 3.42 Suppose  the partial sums of $\sum_n a_n$ form a bounded space $\quad \checkmark$ $c_0 \geq c_1 \geq c_2 \geq \dots \quad \checkmark$ $\lim_{n \to \infty} c_n = 0 \quad \checkmark$  Then $\sum_n a_n c_n$ converges.  Thus $\sum_n a_n b_n$ converges as well. $\quad \Box$ Now that should hold, I think. So I wouldn't need to go through all the estimates. Is there a page listing all fields? Are the review queues planned for the iOS app? unsigned int vs. size_t I notice that modern C and C++ code seems to use size_t instead of int/unsigned int pretty much everywhere - from parameters for C string functions to the STL.  I am curious as to the reason for this and the benefits it brings. Recently I had a bunch of my own scripts for the thumbnails in Nautilus: , , office documents and so on.  Seems like either I’m doing something wrong (thumbnail generation behavior changed), or custom thumbnailes don’t work in latest GNOME at all, even my previous scripts, which worked smoothly on previous versions of Ubuntu.  I’ve done some research, tried to run a simple script (see below) and it didn’t work out.  My test thumbnailer in /usr/share/thumbnailers/z.thumbnailer:  [Thumbnailer Entry] Exec=/home/maximal/thumb.sh %s %i %u %o MimeType=image/webp;image/x-webp   Where /home/maximal/thumb.sh is:  #!/bin/bash echo $0 &gt;&gt; /home/maximal/thumb.log echo $1 &gt;&gt; /home/maximal/thumb.log echo $2 &gt;&gt; /home/maximal/thumb.log echo $3 &gt;&gt; /home/maximal/thumb.log echo $4 &gt;&gt; /home/maximal/thumb.log   Then, when I remove thumbnail cache rm -rf ~/.cache/thumbnails and restart Nautilus nautilus -q, my log file doesn’t contain anything and ~/.cache/thumbnails/fail/gnome-thumbnail-factory contains all the failed thumbs (looks like corrupted/empty PNGs):    So, apparently, Nautilus even didn’t try to execute my thumbnailer script. When I try to run thumb command itself, it works perfectly. For example convert through cwebp|dwebp package:  convert -thumbnail 256x256 file.webp png:file.webp.png   When I wrap this command to a thumbnailer, it looks like it wasn’t even requested to run by Nautilus.  [Thumbnailer Entry] Exec=convert -thumbnail %sx%s %i png:%o MimeType=image/webp;image/x-webp;   Exactly the same situation occurs with other my thumbnailers: audio waveforms, office documents, photoshop files and so on.  Could anyone help? cron job schedule Why does magnet attract iron but not other metals? While searching, i found this page:  but it does not have full explanation. So Please tell full explanation of why this happens? bash dynamic (variable) variable names jQuery get the rendered height of an element? Active Web Site as Gnome Background Is there a way to put an active website, such as Gmail, as your Desktop background in Gnome, running Ubuntu 10.10 64-bit? MS Win calls it "Active Desktop". What advantages does manual mode have over aperture priority mode? I'm wondering what are the most compelling reasons to switch to manual mode on my DSLR. I mostly just use aperture priority mode so I have good control over the depth of field combined with an awareness of the shutter speed that goes with it. My photography is mostly done wandering about with camera in hand, or occasionally on a tripod. I don't do studio photography and I just use the natural light.  I did learn how to take photos manually (with an Olympus OM-1) so I know how to do it, but I enjoy the extra convenience of aperture mode, particularly being able to take the photo quickly and capturing the moment rather than fiddling with dials and missing the shot.  So what would be some key advantages of using manual mode for my sort of photography that are worth the (small amount of) extra hassle involved?  And do you have any tips to minimise the downside (other than practicing to be quick)? What is the correct formula for gravitational time dilation for a satellite in a circular orbit? Nonlinear function continuous but not bounded I would like an example of a map $f:H\rightarrow R$, where $H$ is a (infinite dimensional) Hilbert space, and $R$ is the real numbers, such that $f$ is continuous, but $f$ is not bounded on the close unit ball $\{ x\in H : \|x\| \leq 1\}$.  Actually, $H$ could be replaced by any Banach space (but not just a normed space-- that's too easy).  My motivation is that if $f$ is linear, this is impossible; but I have next to no intuition about non-linear functions.  Edit: Here's an example for $c_0$ which is even differentiable (disclaimer: I found it here: ).  Define $f:c_0\rightarrow F$ (where F is your field, real or complex) by $$ f(x) = \sum_{n=1}^\infty x_n^n \qquad (x=(x_n)). $$  You can estimate the sum by a geometric progression, so it does converge.  A bit of checking shows that f is Frechet differentible (so certainly continuous).  But $f(1,1,\cdots,1,0,\cdots)=n$ (if there are $n$ ones) so $f$ is not bounded on the closed unit ball.  What I don't immediately see is how to adapt this to $\ell^2$, say. A method for evaluating sums/discrete functions by assuming they can be made continuous and differentiable? Prove that there exists at least one $x_0\in\mathbb{R}$, such that $f(x_0)+f''(x_0)=0$ Let $f:\mathbb{R}\to\mathbb{R}$ be a function, two times   differentiable with $\left|f(x)\right|\leq1,\forall x\in\mathbb{R}$   and $f^2(0)+\left(f'(0)\right)^2=4$. Prove that there exists at least   one $x_0\in\mathbb{R}$, such that $f(x_0)+f''(x_0)=0$.   I have tried the usual Rolle method by $e^x$, but didn't go far... Any help available? Is it alright to use lowercase "i" or should you always use "I" (uppercase)? Which singular names ending in “s” form possessives with only a bare apostrophe? Many questions already ask about this topic ( , , etc.) and their answers vary, but they always give exceptions to the apostrophe-s rule, for example:      6.24 The general rule for the possessive of nouns covers most proper nouns, including most names ending in sibilants."   Examples they give include Kansas’s, Ross’s land, and Jones’s reputation. Exceptions include Jesus’  and Moses’.  Which names does this apply to?  Is the Aeneas’  form correct, or is it Aeneas’s instead? We have a restricted Windows 7 computer that hides and prevents non-admin users from accessing the C Drive using the following policies:       However, they are able to circumvent this by typing the following into Explorer: \\localhost\C$  How can I disable this path but allow other UNC paths. For example they are allowed to access a shared folder on a different computer. eg. \\192.168.2.1\SharedTransfer  Note: Simply Enabling the Group Policy: Remove Run menu from Start Menu will not work as this blocks all UNC paths.  Update  The user, called Site User, is not a member of the Administrator group directly or indirectly. It is only a member of the group Users.  Accessed the following from: Control Panel\All Control Panel Items\Administrative Tools\Computer Management (Local) &gt; System Tools &gt; Local Users and Groups   Local Users and Groups  - Groups       - Administators              - Administrator              - Service User (our admin user)       - Users              - NT AUTHORITY\Auntenticated Users (S-1-5-11)              - NT AUTHORITY\INTERACTIVE (S-1-5-4)              - Site User (user account in question) Bounty-like facility for rewarding excellent questions Amongst the reasons for starting a bounty, one can select:     Reward existing answer      One or more of the answers is exemplary and worthy of an additional bounty.   Why not enable one to reward excellent questions in a similar manner?