Meaning of resistor power rating

Question: I am struggling to understand the meaning of the power rating of a resistor (e.g. 2 Ω, 40 W).
How may this power rating impact the discharge performance of a battery whose terminals are connected to the resistor?
Answer: The power rating is how much power the resistor can dissipate before going up in smoke.
A 1 A, 12 VDC incandescent lamp is ~12 Ω resistor (at operating temp) able to dissipate 12 W while glowing white hot.  Put much more voltage through (e.g., plug it into 230 VAC mains, where it would dissipate ~4,400 watts for an exceedingly brief moment), and it will become an open circuit, after an actinic flash of light.

(Image adapted from: 1000Bulbs.com - Bulbrite 715710 - 10 Watt - T3.25)
However, an electric clothes dryer might have a 12 Ω element, the size of a loaf of bread, that can dissipate 4,400 watts as long as the airflow is not blocked.

(Image adapted from: Walmart.com - Dryer Heating Element)
Both are 12 Ω, but one is rated at 12 W, the other at 4,400 W.
Answer: A resistor power rating (in watts) indicates how much power it can dissipate before failing or destroying itself.
Current is voltage divided by resistance (\$I = \frac{E}{R}\$). If you have a 6 volt battery connected across a 2 Ω resistor, the current will be 3 A.
Power is equal to the product of current and voltage (\$P = IE\$), which would be 36 watts in this example. If you exceed the rating of your resistor, 40 watts for the one you cited, the resistor will fail.
Power dissipation depends on some other factors as well, such as cooling. If you have active cooling you may be able to meet or exceed the component rating, but you should check the datasheet for the conditions under which the power rating was derived.
Answer: Resistor gets hot. For instance, you have current up to 10 A, so your 2 Ω resistor will emit 10×10×2 = 200W. Too much by any means, right? So if you plan to discharge the battery at 10 A, 2 Ω is not good. You must be well below maximum power.
Besides, I guess you have your battery in an enclosure; you probably wouldn't want to emit too much heat there. It is not related to resistor absolute maximum power, but is an important consideration also.
Answer: The resistor current rating will have no effect on the battery. A resistor ideally maintains its resistance no matter how many watts its currently dissipating.
As others have stated the wattage rating reflects how much the resistor can handle without being destroyed.
As long as the resistor is functioning properly "12ohms is 12ohms", as far as the battery is concerned.
Answer: The power rating of a resistor is the maximum power that it can dissipate (as heat), without getting damaged.
Consider a resistor 'R' that draws a current 'I' and dissipates power 'W' when a voltage 'V' is applied to its terminals.
Applying Ohm's Law
I = V / R
The power dissipated by the resistor
W = V * I = I² * R = V² / R
Thus the permissible voltage across the resistor or the permissible current through it, may be calculated.
The permissible voltage across a 2 Ω, 40 W resistor is √(2 * 40) = 9 V and the permissible current √(40 / 2) = 4.5 A.
Battery discharge time is influenced only by the resistance of the load and not by it's power rating.

Meaning of resistor power rating


Administrator Password lost for a Win 2003 Server machine

Question: We have lost the administrator password of a Windows Server 2003 machine which is used in our lab.
Is there any way to reset or recover the password without reinstalling Windows?
Comment: for the local machine? or the AD domain admin account?
Comment: I just checked this and the computer doesnt have an option for LOCAL MACHINE login , it only has a AD login . So would the rescuse disk option really work in this case ? I am planning to use Trinity Rescue Kit
Comment: I think we may be talking at cross purposes here. Could you extend your question? Is it a local Windows admin password you have lost? Can you login to the machine with a domain admin account? Why do you need to login as a local admin rather than a domain admin?
Answer: There is a linux live CD that contains an utility for changing the password. I managed to reset my lost administrator password that way. Here is the link: http://pogostick.net/~pnh/ntpasswd/
Edit: if the server is a domain controller (i.e. you are not able to log in to "local machine") you can always login as "local" admin in domain recovery mode (accesible by pressing F8 during startup), there is a step-by-step guide how to reset W2k3 domain admin password here: http://www.petri.co.il/reset_domain_admin_password_in_windows_server_2003_ad.htm
Answer: Obtain a Linux rescue cd like Trinity Rescue Kit, boot in single user mode (if using TRK) and run winpass from it.  Select the blank password option and set a new administrator password within the 2003 box.
Comment: Will TRK work the same for a machine that has DOMAIN LOGIN only ?
The comp doesnt show any option for local login .
Answer: OPHcrack is a good shout depending on how complex your password was
http://ophcrack.sourceforge.net/
also you can try this can be a bit messy tho
http://www.petri.co.il/forgot_administrator_password_alternate_logon_trick.htm
Comment: +1 I have use ophcrack more times than I can count, and with easy success every time.
Answer: If the machine is on a domain, login to it with an account that is in the Domain Admin group then you should be able to reset the local admin password.
If it isn't on a domain (or there is something locking a domain admin from changing the local admin password) then one of the many boot disks that can reset NT password (see other people's replies for links) will do the trick - I've used similar tools successfully in the past.
If there is anything important on the machine then I suggest that you try back it up before messing around, just for paranoia's sake in case the password resetter fails in a way that makes things worse. If you boot from any good Linux Live CD you should be able to mount the drive nd read the files, and mount a network share to copy important ones to (or you could take a full image of the drive, but that is almost certainly overkill).
Comment: David , the machine has only domain login and shows no option for local login . We use this as a Tier 2 ( GUI utilities mainly) machine for a telecom software
Comment: Security policy for the domain may be blocking local login. If that is the case then you will need to login as a member of the domain admins group, reset the/a local admin password, then drop the machine off the domain. Also, you could try login as \ - it may allow you to login as a local user that way even if the non-domain option is not displayed explicitly.
Answer: Instead of booting to a Linux Live CD and hacking at it, you can use a commercial product like  "Active Password Changer" (http://www.password-changer.com/) that costs $50 and it will make it super easy for you do view or reset any of the windows passwords on any machine. Its almost ridiculously easy to use.
Answer: To reset local admin password for your Windows 2003 machine, you can try the free Linux CD - Offline NT Password & Registry Editor. Boot your machine from the CD and follow this video guide you can remove forgotten password in minutes.


Can you run SAS drive from SAS backplane to SATA on mobo?

Question: Have an SAS drive plugged into SAS port on the backplane, and it is connected to SATA on the motherboard. Is it possible to use it this way? It is a testing server for cloning another SSD.
Answer: No, that won't work. SATA controllers don't speak SAS nor do SAS drives speak SATA.
You can connect SATA drives to (most) SAS controllers, but not vice versa.
SAS drives also require a SAS backplane, they won't fit into a SATA backplane mechanically.
Comment: It's not a SATA backplane, it is a SAS backplane that is connected to MOBO over sata. To clarify, will this setup work or no?
Comment: A SAS backplane is not a problem - SAS drives won't fit a SATA backplane - the SATA controller is.


Add menu item programmatically Drupal 6

Question: I am trying to add a menu item to a custom menu programmatically in Drupal 6 and have almost gotten it but ran into a weird problem. I can add the item to the menu using the code: drupal_execute('menu_edit_item', $item_array, 'add', NULL, array('menu_name' => $menu_name));
drupal_flush_all_caches();
This somewhat works, but for the link to actually show up in the menu I have to either save the page twice, or save the page and clear the cache from Admin > Performance. Does anyone know why I need to flush the caches twice, or is there a better way to do this? Let me know if you need any more information, I included what I thought was relevant but I may have left something out.
Answer: To add menu items use hook_menu():

This hook enables modules to register paths in order to define how URL
  requests are handled. Paths may be registered for URL handling only,
  or they can register a link to be placed in a menu (usually the
  Navigation menu).

example:
function YOUR_MODULE_NAME_menu() {
  $items['a/b/c'] = array(
    'title' => 'Example menu',
    'page callback' => 'example_callback',
    'access arguments' => array('access content'),
    'type' => MENU_NORMAL_ITEM,
    'menu_name' => 'your-custom-menu-name',
  );
  return $items;

}
To learn more about hooks see here
Comment: Thanks, but this doesn't work for a custom menu. I understand how hook_menu works. I need to add a link to a custom menu I created programmatically.
Comment: OK. see the edited post(menu_name).
Comment: hook_menu is definitely *not* for adding links to menus.
Answer: The API you are looking for is menu_link_save. And, as documented use menu_cache_clear_all after.
Answer: Try menu_rebuild() instead of flushing caches.

(Re)populate the database tables used by various menu functions.
This function will clear and populate the {menu_router} table, add
  entries to {menu_links} for new router items, then remove stale items
  from {menu_links}. If called from update.php or install.php, it will
  also schedule a call to itself on the first real page load from
  menu_execute_active_handler(), because the maintenance page
  environment is different and leaves stale data in the menu tables.

Add menu item programmatically Drupal 6


migrating Microsoft apps from windows 2003 server to windows 2012 server

Question: we have more than 30 classic asp and .net applications to be migrated to windows 2012 server from 2003 server.This is new task for me, so what are the steps/factors i need to consider or fulfill for this migration? with that I mean like there are COM objects, dependent dll's all stuff so what things I should ensure are in place for smooth migration.
Microsoft provides ACT tool for Application Compatibility test how much will that support? or are there any other better proven tools for the same purpose?
any insight/help would be appreciative.
Thanks.
Answer: First thing to assess is "what works and what doesn't work". There's a high chance that many of these apps will just work. That's the first thing to go do. Start by coming up with some test criteria by which the program is expected to work. Then deploy to the new OS.
One problematic area might be that these executable program require an older version of .NET or the MSVCRT DLLs that might not be on the box by default. The MSVCRT redist is easily available from Micrsoft's web site. You can install older versions of .NET from Control Panel->Programs and Features->"Turn Windows features on or off". Look for the ".NET" checkboxes near the top.
For classic ASP applications, same thing in the "Turn Windows features on or off". Look at "World Wide Web Services" node and make sure ASP (and most all of those other features) is selected.
Answer:
Microsoft provides ACT tool for Application Compatibility test how much will that support? or are there any other better proven tools for the same purpose?

In my experience with automation tools, especially when working with older sets of technology (like classic asp)they rarely work near as well as advertised.


Rabbit constantly digging and trying to bite

Question: hi I have a female rabbit of approx 6 months she is newzealnd Albino rabbit . Since last few days she has started digging a lot and also tries to bite us . So Kindly let me know what can be reason
Comment: Can you tell us a bit more about how she usually lives? What types of enclosure does she have? What's in the enclosure? Does she live inside or outside most of the time? Has she been with a male or is she pregnant?
Comment: No she is not with Male she lives inside . I dont keep her in cage she lives and roams freely in my home. She has neither pregnant nor she has been with male.
Answer: Digging:
Rabbits like to dig. Not only like it: They need to dig to stay healthy. You should add some kind of "sandbox" into the area she can use regularly. For example a simple box with an entry from above (for example with stairs or ramp) filled with soil, straw or similar.

source: kaninchenwiese.de
If they can not follow their instincts, they will feel stressed and react with aggression. (In case the space for the rabbit is not big enough, rabbits would dig to overcome borders. Also if the rabbits do not feel save enough, they would dig to get a save place to hide.)
Biting:
Biting is a sign of feeling not comfortable with you near her. First you need to bring her to a vet to verify if she has no health reasons for feeling uncomfortable, like pain. Second you need to make her feeling comfortable with persons around: include places to hide in her area (best: something she can hide inside and have a secure look to persons outside, like this kind of wooden boxes with spaces between the boards). Do not pick her up from above (she would associate this with a bird of prey, fight and remember you in a bad manner). And you need to give her a rabbit as companion. Humans are not able to exchange a real rabbit, even if they would be there 24/7 and would really try. The rabbit would not understand the body language of the human and so feel really lonely, especially because rabbits are animals with a big family in the nature. The rabbits share the task to look out for dangers, but one alone feels the pressure to do this all time without breaks. (Females are most easy to accompany with males, but one of them need to be spayed!)
I like really that your rabbit can roam freely! Enough space is most times the problem where I live. But if you really want a happy rabbit, you need a second one. Beneath the spaying two of them would not cause more effort than one alone, more the other way around, because the rabbits would entertain themself when no human is around and so they would not start to behave bad.
Comment: Read also this question: [Rabbit alone, good idea?](https://pets.stackexchange.com/questions/25974/bunny-alone-good-idea)


How can I implement Web Services in Perl?

Question: How to implement Web Services in Perl?
Comment: I think the downvotes were due to the very broad nature of the question.
Answer: I prefer XML::Compile::SOAP.  I admit that I am not a heavy SOAP user, but I have heard from heavy SOAP users on IRC that XML::Compile::SOAP is a dream come true for them.
The other day, I was writing a small script to extract data from a SOAP-accessible database.  I tried XML::Compile::SOAP, and the whole data-extraction function ended up being five lines!  One line to load the WSDL, one line to compile the function I wanted to call, one line to call that function (the Perl argument was automatically validated against the WSDL specification, and converted from native Perl structures to the weird Java structures on the other end), and one line to munge the result a bit.  After hearing people complain about how hard SOAP is, I couldn't have been happier.
JMHO.
Answer: Programming Web Services with Perl is a bit dated (2002?) but still should be read.
It also has a companion web site.


Converting IDE optical drives to SATA with an adapter - not recognised in BIOS or OS

Question: My wife's 10 year old desktop computer failed some months ago, which necessitated the purchase of a more modern motherboard.
The original motherboard had both IDE and SATA ports and the computer has a 1TB Western Digital SATA HDD and two IDE optical drives, and is using Windows 7 'Ultimate' 32 bit OS.
The new motherboard has (6) SATA ports; no IDE port, and not wanting to buy new optical drives, I bought a couple of fairly inexpensive "40 Pin Convertor Portable Data IDE To Serial SATA Connector Adapter Hard Drive" to convert the drives to a SATA interface, and be able to use them.

I've finally got around to fitting them this weekend, (they plug into the 40 pin IDE connector at the back of the drive) but they appear to have been spectacularly unsuccessful!
The drives aren't recognised in the BIOS, despite me trying just about everything I have read both here and elsewhere.
I've checked the selection jumpers - they were both on CS (cable select) and have been moved to M (master). No joy.
I have plugged the drives into SATA ports 5 and 6 which can be set as IDE in the BIOS; have 'told' the BIOS they are 'CD-ROM' drives and also tried 'Auto'.
No joy.

I've plugged the signal cables into ports 2 and 3 (the HDD is in #1 and they are set to AHCI); left recognition as 'Auto' but still no joy.
I've tried various combinations of SATA settings in the BIOS, but nothing seems to work. There is one niggling issue.
The adapters came with a power cable with a female 4 pin Molex connector on one end, and a Berg connector - similar to that used on floppy drives - on the other end. The adapter has a Berg connector on the side - it can be seen at the top of the adapter.
Now, I have provided power to the adapters via the standard SATA power connectors that are part of the wiring harness of the power supply.

Is this adequate? (If it isn't - well, as all the Molex connectors in the harness are also female, I have a serious problem!!).
Has anyone had any success with this type of adapter?
If so, I would be delighted to know what the secret is!!
et me add that, as expected, data or information on the adapters is zero! (You can see them on eBay at: https://www.ebay.com/itm/40-Pin-Convertor-Portable-Data-IDE-To-Serial-SATA-Connector-Adapter-Hard-Drive/274054074053). Oh, and both optical drives worked - perfectly - as IDE drives, and as they haven't been used or even powered since then, it's extremely unlikely they have both suddenly failed.

UPDATE:
I've noticed in the motherboard manual that it suggests that optical SATA drives are best plugged into SATA ports 5 and 6; that they are defined as 'CDROM' in the BIOS and that the ports are set to be IDE and not AHCI.
So, I've tried that - and as before, the BIOS claims that the devices installed on those ports are 'ATAPI incompatible' and show as 'not installed'.
In other words, not a scrap of difference!
I've also tried uninstalling the IDE adapter in the Win Control Panel, and allowing it to - hopefully - 'find' devices.
You probably won't be surprised to learn it doesn't.
I won't give up yet - I'm still hoping that someone can advise whether the SATA power connector is sufficient, or whether I have to plug power in via the Berg connector (and hence get/make some male - male Molex connectors).
But it's increasingly looking like these adapters are a proverbial lemon!!
Comment: There are very few IDE to SATA adapters of that type that work well. You are better to use a PCI controller card card instead. What PC or motherboard do you have
Comment: Yes, I'm sort of hearing that they aren't the best. I haven't given up hope yet! The m'board is an Asus M5A78L-MLX The BIOS is v1603 dated 5 Nov 2013 (I think - it says 11/5 but I assume that's US date format......). According to the Asus spec - AMD SB710 controller; 6 x SATA 3Gb/s port(s), blue; Support Raid 0, 1, 10, JBOD (is that "just a bunch of drives"?). As I said before, ports 5 and 6 do appear to be 'different' in the BIOS setup. They are currently unpopulated, though. Manual is available as a zipped file here: https://www.asus.com/Motherboards/M5A78LM_LX/HelpDesk_Manual/
Answer:
I won't give up yet - I'm still hoping that someone can advise whether
  the SATA power connector is sufficient, or whether I have to plug
  power in via the Berg connector (and hence get/make some male - male
  Molex connectors).

Plug the Berg connect in to the adapter then plug the molex straight into the optical drive. Plug the Sata power cord into the adapter. Voila! I was doing same thing you were until I saw this video https://www.youtube.com/watch?v=Lsxd9Ide6qs
My optical drive was set to Cable Select mode. Be sure to switch this to Master (Master worked for me I didn't try Slave).


How to prove secret value in Pedersen commitment is equal to secret value in Fujisaki commitment?

Question: We have Pedersen commitment C to the secret value x, and Fujisake commitment C' to the secret value x. How can we make a zero-knowledge proof of equality for x value in the commitments?
Answer: This may look like a homework, so I would not present any complete "Ctrl-C Ctrl-V" -style solution.
A proof for equality of logarithms was introduced at Chaum, Evertse and van de Graaf paper, "An Improved Protocol for Demonstrating Possession of Discrete Logarithms and Some Generalizations", Eurocrypt 1987. At the core, Prover shows that the same single response would open both commitments.
According to http://kodu.ut.ee/~lipmaa/crypto/link/commitment/,
Fujisaki-Okamoto commitment scheme (spelling warning) is somewhat similar to Pedersen.
Major difference is operating with a group of an order hidden from Prover, which makes it acceptable to commit to integers (not only elements of a field of residue classes modulo prime group order).
This difference does not prevent from using the same response, as was stated.
Having said this, I would encourage to do it yourself.


How do I install a non-PAE kernel on PAE-enabled hardware for Ubuntu 12.04?

Question: I need to install a non-PAE kernel for a 64-bit machine that supports PAE. 32-bit 12.04 currently comes with a PAE kernel but I need to get a non-PAE kernel. An older version of Ubuntu is also acceptable as long as it runs in 32-bit mode.
Answer:
32-bit 12.04 currently comes with a PAE kernel but I need to get a non-PAE kernel.

It's as simple as doing this on your existing 32-bit 12.04 installation:

sudo apt-get install linux-image-generic

followed by a this to remove the PAE kernel (so the system boots from the non-PAE by default):

sudo apt-get remove linux-image-generic-pae
Alternatively, comment out the GRUB_HIDDEN lines in /etc/default/grub and run sudo update-grub to display the grub menu upon boot, from which you can select the kernel to use.

If you want to install a non-PAE kernel as part of a new installation, start with Xubuntu or Lubuntu 12.04 32-bit, both of which come with the non-PAE kernel. Once running, you can run sudo apt-get install ubuntu-desktop to get the full Unity desktop experience.
In general, the two common kernel suffixes for 12.04 are:

-generic (non-PAE for 32-bit; standard for 64-bit)
-generic-pae (PAE and default for 32-bit only)
Answer: I couldn't install non-pae kernel with this command (from previous answer):
sudo apt-get install linux-image-$(uname -r)-generic

But on output was a kernel version, in my case 3.2.0-27, so I modified the command:
sudo apt-get install linux-image-3.2.0-27-generic

And it worked!
Comment: Sorry for the mistake -- please see edited answer. Just installing the metapackage `linux-image-generic` should be enough and will allow for seamless upgrading whenever new kernels of that variant are released.


Range of values of virtual runtime in CFS scheduler

Question: I am trying to understand the working of the Linux CFS scheduler using kernel version 4.19.2.
As mentioned in the documentation, it does not use timeslices in the traditional way but uses the concept of virtual runtime. The update to this vruntime for every process is made in the file kernel/sched/fair.c
The exact line for the update is
<code>    curr->vruntime += calc_delta_fair(delta_exec, curr);
   //curr is the currently scheduled task, the function cal_delta_fair()
   returns a value depending on the duration the task ran and its priority
   ensuring fairness.
</code>
The variable vruntime is u64, defined in the kernel types as unsigned integer of 64B. To understand how the vruntime varies for a process, I wrote a system call to get it's value out, which turned out to be negative as well as positive at times. How? What does a negative value for vruntime signify?
Answer: The datatype of vruntime is an UNSIGHNED 64 bit integer. If you are reading negative numbers, then i think you need to cast the variable to the right type in your system call implementation


Connection error

Question: I have got connection timed out error while logging into the putty to connect to my raspberry pi-3 model B board.As per the documentation I have created an empty ssh text document but even then its showing the connection timed out error.Where did I go wrong?how can I fix this error?
Comment: Can you ping the Pi? "Connection timed out" suggests it's not able to connect to the device at all.  Could be general network issues.
Comment: How is the Pi accessing the network?
Answer: This is how i did a headless setup on my mac (should work on other conputers also)

Downloaded etcher and latest raspbian desktop image

2.inserted sd card, burned zip file with etcher to it.

etcher automatically ejects the sd card, reinsert it and make a text document named ssh (make sure it doesnt have an extension!)
copy the sh file to sd card and eject the sd card.
insert sd card micro usb and ethernet cable from pi to your router.
power up RPi, wait 2 mins than goto your routers ip address and type in your crednentials.
fibd device connected and find your raspberry pi ip address
open terminal and type ssh pi@(ip address of rpi)
enter raspberry as the password
change your settings with sudo raspi-config and reboot.
if you want to vnc to it enable vnc and connect.

Hope this helps!

Connection error


Apparatus for generating plasma

Question: I'm working on a project which involves superheating nitrogen to a state of plasma. I was considering using my Fusor, but this project has nothing to do with plasma, and I believe that there are way more efficient goals for achieving plasma. Thank you for helping a fellow scientist (in the making)
Comment: Do you need to put it into something?
Comment: I know a method, but removing from the container would be difficult.
Comment: Look into radio-frequency electromagnetic fields. I think this is the common way to produce plasma.
Comment: @TheloniousMonkey Do you have any other requirements besides using nitrogen?  What pressures do you want to operate at?  What size volume are you working with?  What equipment do you already have available to you?
Answer: In a comment engineer has suggested using radio frequency induction, and this seems an excellent idea. The technique is widely used, for example in plasma etching, and it's not especially high tech. There is a Wikipedia article that describes the technique, though this is a bit short on practical advice. A Google search returns lots of likely looking hits.
Answer: Perhaps you could fill us in on some more details about what your application is. There are a whole bunch of ways to produce plasmas and the techniques vary largely by the application. For example DC or RF fields applied across a very small gap are used for plasmas that need to be produced at atmospheric pressures (DBDs). At the other end of a scale, a mixture of high energy beams of atoms and wave heating are used to drive the very temperature plasmas required for fusion experiments (tokamaks.
One of the easiest ways to produce a plasma is using radiofrequency fields as suggested above. There are a whole bunch of ways of doing this too though, usually by using different shaped antennas (CCP, ICP, helicon for examples). The easiest of these is probably an inductively coupled plasma reactor (ICP), which would just be a copper wire would around you vacuum tube a few times with radio frequency power (13.56Mz is common) applied. The power you need to apply will depend mostly on the size of your device and the pressure of the gas. Nitrogen isn't too difficult though, so if it's a lowish pressure (~100mTorr) and not too large (say 20 cm long and 5-10 cm in radius), a <200 W would produce a plasma.
Let me know exactly what you're trying to achieve though and I can provide more details.

Apparatus for generating plasma


How to convert a language item to another language

Question: I have created some test content in english on the sitecore site that I am working on. But I want the site to be in french, so I want to convert all the english content to french one-on-one and I want to do this without code. So I want to create a french versions with all the field content from the english versions (and thereafter I will remove the english content). I have been looking around the sitecore interface, but can't find anything for this purpose. So what is the easiest way to accomplish?
Comment: You may want to try to use a module from the marketplace named "[Smart Tools - Add Version and Copy Content](https://marketplace.sitecore.net/Modules/S/Smart_Tools_Add_Version_and_Copy_Content.aspx?sc_lang=en)." This should allow you to copy the items you want to the language you want via the Sitecore interface.
Comment: What version of Sitecore. You want to convert a single page or you want the whole site in one shot?
Answer: Most easy way is to use Sitecore Powershell :
First time you need to add copy from english to french.
For recursive you can try below PowerShell script
<code>Get-ChildItem /sitecore/content/home -Recurse  |
  ForEach-Object { Add-ItemLanguage $_ -Language "en" -TargetLanguage "fr-fr" -IfExist Over
</code>
To delete old items from english you can use:
<code> $path = "master:\sitecore\content\yourpath"
@(Get-Item $path) + (Get-ChildItem $path -Recurse) | Remove-ItemLanguage -Language "en"
</code>
Answer: Without code, there is a manual approach that you can do to copy paste values across.

On the item, select the French language version. It should warn you that no versions exists.
Create a new version. By default, the fields will be blank.
Turn on the 'Translate' button in the ribbon and it will let you see the English and French side-by-side.
Copy paste the values.

For added ease, you can enable Raw Values display so you can easily copy over GUIds and the like for select fields and media fields.
Another way, which I haven't tried before, and is incredibly hacky, would be to change all your template fields to be Shared, then create the French versions, then change the fields on the templates back to unshared. Not sure, but it might copy the values over in that scenario?


Arduino Rubber ducky?

Question: So there is this hacking tool called a rubber ducky , the concept is that the device looks like a flash drive but the computer thinks it's a keyboard . According to what i know , a usb port has 4 wires , VCC GND and 2 for data , so i thought if it was possible to take a usb cable , cut it and connect it to the arduino accordingly , and send the computer that data so that he would think i connected a keyboard , and basicly create a fake reprogrammable keyboard
Comment: You mean buy an Arduino Leonardo or Arduino Micro and plug it in?
Comment: @Gerben I would never touch a solution like that even with someone else's barge pole. Bit-banged USB is very very nasty, and a 5V (non-USB) Arduino doesn't have a suitably compatible electrical interface to USB which risks damaging your hub or computer.
Comment: You can fake a keyboard using VUSB for AVR.
Answer: Most Arduinos can't be a USB keyboard (not without some really nasty bit-banging code and dodgy electronics).
Some can, though - such as the Arduino Leonardo or the Arduino Micro. And you don't need to cut any cables, you just plug it in.
Comment: i meant like if i take a usb cable and cut it and connect the according wires of the usb cable to the arduino and sending data , any chance the computer can see this data and think a keyboard or mouse has been connected ?
Comment: Why take a cable and cut it? Just plug it direct into an Arduino that is designed for the job!
Comment: I mean sending raw data , since when i connect and arduino , it sends the pc certain bytes that tell the pc that is an arduino , but i want to trick the pc  into thinking that is a keyboard
Comment: So you mean plugging in an Arduino that is designed for the task, like the Arduino Leonardo or Arduino Micro? Do you actually have the faintest clue what an Arduino Leonardo or Arduino Micro actually are?

Arduino Rubber ducky?


Male with X-chromosome matches from father's side?

Question: I am a male and in my FTDNA DNA-matches, when I filter for matches by X-chromosome match, I get around 30 people who can only be possible relatives from my father side (my parents came from distant European countries, the matches are from the region my father was born, and one of the matches is most likely related to my paternal grandfather. Is there a possible explanation or there's some kind of mistake in the test?
Answer: FTDNA will include segments as small as 1cM in X-matches; you'll need to compare in the chromosome browser to see how much you share with these paternal matches. If these matching segments on the X chromosome turn out to be very small segments, they're most likely Identical By Chance (IBC) and can be disregarded.
Comment: @S.B. Are you absolutely positive those segments are on the X-chromosome? If your mother is still living, is she willing to test?
Comment: Have you researched your mom's side, genealogically, to see if she has any ancestors who may have travelled from Sweden and landed in Spain? Can you link maternal matches to branches in your mom's side of the family?
Answer: There are many possible explanations.
First, make sure these are really X matches.  As others have suggested, look in the chromosome browser.  The filter may or may not be accurate.
Second, I agree with Leah: disregard segments that are too small.  All segments are "real" but that's not the same thing as "meaningful."  Anything less than 5 cM is almost always useless.  For regular autosomal, most people only look at segments at least 7 cM.  X recombines less often so aim for segments of at least 10 cM.
Third, your ancestors traveled around a lot more than you might think.  I mean if your dad was from Scotland and your mom was from Burma, there's probably not a lot of doubt which side you match someone on.  But Scotland and Romania?  I wouldn't make assumptions.  And with the Roman empire moving all over Europe, you get Middle-Eastern and Northern African migrants too.  It's just not something where you can state "my family is from such and such country and has always been from such and such country."


Why does ethereum.org suggest different prototypes for 'buy' and 'sell' functions?

Question: Scrolling https://www.ethereum.org/token approximately half way down, I read this:

The next step is making the buy and sell functions:

function buy() payable returns (uint amount){
    amount = msg.value / buyPrice;                    // calculates the amount
    require(balanceOf[this] >= amount);               // checks if it has enough to sell
    balanceOf[msg.sender] += amount;                  // adds the amount to buyer's balance
    balanceOf[this] -= amount;                        // subtracts amount from seller's balance
    Transfer(this, msg.sender, amount);               // execute an event reflecting the change
    return amount;                                    // ends function and returns
}

function sell(uint amount) returns (uint revenue){
    require(balanceOf[msg.sender] >= amount);         // checks if the sender has enough to sell
    balanceOf[this] += amount;                        // adds the amount to owner's balance
    balanceOf[msg.sender] -= amount;                  // subtracts the amount from seller's balance
    revenue = amount * sellPrice;
    msg.sender.transfer(revenue);                     // sends ether to the seller: it's important to do this last to prevent recursion attacks
    Transfer(msg.sender, this, amount);               // executes an event reflecting on the change
    return revenue;                                   // ends function and returns
}

Why does the sell function take the input amount as an argument, whereas the buy function receives it inside msg.value?
I initially thought the reason might be that standard wallets (Mist, MyEtherWallet, Parity, etc), which see the payable keyword and detect this function as an "Ether Receiver", pass everything inside msg.
But it doesn't quite make sense to me that ethereum.org conforms to standard wallets (i.e., ethereum.org should be the one dictating the standard, not the one complying to it).
So what exactly am I missing here?
Thank you!
Answer: The code for selling requires the amount the tokens you want to sell. The buying part assumes the amount indirectly from the price and the ether sent. Because in any case, you need to send the ether equivalent to the amount you want, asking for the amount is redundant.


How do I export an Android Studio project?

Question: I just started using the Android Studio IDE and I already released and published a simple APK to Google Play store.
The problem is that I did this at work.
Now I downloaded the Android Studio at my home and I want to continue working and fixing bugs on my Project.
I see that there is Import Project in the Android Studio home screen, but from where I export the project in order to import it?
I tried Zipping my whole Project folder and import it but it didn't work very well.
Comment: Just copy your entire project folder and point to that folder in the import wizard
Comment: I wrote that I tried to do that, but it gave me some kind of "rendel" errors when I opened it.
Answer: In the Android Studio go to File then Close Project. Then take the folder (in the workspace folder) of the project and copy it to a flash memory or whatever. Then when you get comfortable at home, copy this folder in the workspace folder you've already created, open the Android Studio and go to File then Open and import this project into your workspace.
The problem you have with this is that you're searching for the wrong term here, because in Android, exporting a project means compiling it to .apk file (not exporting the project). Import/Export is used for the .apk management, what you need is Open/Close project, the other thing is just copy/paste.
Comment: is it necessary to copy the whole project directory? Including the various "build" sud directories? My concern here is the space. With all the various sub-directories and build outputs the zip directory is almost 10Mb.
Comment: Thank u man, I did this and ran into a different problem.
I posted it as a different question, please take a look if you can:
http://stackoverflow.com/questions/18624666/how-to-change-gradle-sdk-settings-when-opening-android-studio-project-from-a-dif
Comment: I posted a comment on the link you provided.
Answer: As mentioned by other answers, as of now android studio does not provide this out of the box. However, there are ways to do this easily.
As mentioned by @Elad Lavi, you should consider cloud hosting of your source code. Checkout github, bitbucket, gitlab, etc. All these provide private repositories, some free, some not.
If all you want is to just zip the sources, you can achieve this using git's git archive. Here are the steps:
git init       # on the root of the project folder
git add .      # note: android studio already created .gitignore
git commit -m 'ready to zip sources'
git archive HEAD --format=zip > /tmp/archive.zip

Note: If you intend to send this by email, you have to remove gradlew.bat from zip file.
Both these solutions are possible thanks to VCS like git.
Comment: what about importing zip? how can we handle this?
Comment: Just unzip and in android studio, use "Import Project" and point to the unzipped directory.
Answer: It seems as if Android Studio is missing some features Eclipse has (which is surprising considering the choice to make Android Studio official IDE).
Eclipse had the ability to export zip files which could be sent over email for example.
If you zip the folder from your workspace, and try to send it over Gmail for example, Gmail will refuse because the folder contains executable.
Obviously you can delete files but that is inefficient if you do that frequently going back and forth from work.
Here's a solution though:
You can use source control. Android Studio supports that. Your code will be stored online.
A git will do the trick. Look under "VCS" in the top menu in Android Studio.
It has many other benefits as well. One of the downsides though, is that if you use GitHub for free, your code is open source and everyone can see it.
Comment: Exactly. GitHub is useless if you just want to backup your own code privately unless you don't mind paying a monthly fee!
Answer: Source control is best way to handle this problem, if you don't want to pay then try bitbucket
It's free, allows private repo for upto 5 members team.
Answer: Windows:
First Open Command Window and set location of your android studio project folder like:
D:\MyApplication>

then type below command in it:
gradlew clean

then wait for complete clean process. after complete it now zip your project like below:

right click on your project folder
then select send to option now
select compressed via zip
Answer: Apparently, there's a lot of "dead wood" in the "build" directories of a project.
Under linux/unix, a simple way to get a clean, private backup is to use the "tar" command along with the "--exclude=String" option.
For example, to create an archive of all my apps while excluding the build directories, I have a script that creates the following 2 commands :
cd $HOME/android/Studio
tar cvf MyBackup-2017-07-13.tar Projects --exclude=build

Answer: For Android Studio below 4.1:

From the Top menu Click File and then click Export to Zip File

For Android Studio 4.1 and above:

From the Top menu click File > Manage IDE Settings > Export to Zip File ()


Response to "Excuse me" when some one wants to pass you

Question: It has happened to me a lot that when  I am searching for an item in aisle in a supermarket and somebody says  "excuse me" and passes me. What is a natural response to excuse myself here? What should I say?
Comment: Apart from "You are excused", which sounds haughty, there is not really an answer nor a need for an answer.
Answer: In the Uk the most common response is...." [Silence] ", occasionally, it accompanied with a scowl - meaning "How dare you ask ME to move out of your way... I'm far too important!" or "Oh, I'm Sorry".  Brits do tend to apologise at every opportunity - even if it's not our fault!
I usually try to smile sweetly as I apologise :-)
Answer: In Pakistan, its considered to give space and say nothing. Some people reply back saying "Excused" which feels a bit strange.


Blank browser after clearing the cache

Question: I migrated a site from windows xampp to ubuntu. It was working fine. But once I cleared the cache, the browser is showing blank screen.I tried going to different urls . I also tried clean urls but nothing is coming. All I can see is a white/blank browser.
Comment: check the logs, they usually point to the problem, on ubuntu check your apache and syslogs.
Comment: i guess your ubuntu is a local environment without any access limitations, additionally suggest that you check the php error log for any quick hints of code level errors (ensuring that error reporting is on and set to a preferred level...)
Answer: The White Screen of Death (Completely Blank Page) is a good starting point to takle down the problem.
For D7, extension=php_domxml.dll in php.ini must be commented out. With that dll enabled, I got a blank screen too in Windows.
Check with your php configuration in your linux server.
Comment: the given link worked for me . I just had to make some changes in index.php. I added this in index.php.                                                                                <?php

error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);
Comment: What did you see the error on your screen after you enabled error reporting?
Comment: The error was regarding a module that I was not even using anymore. So I deleted that module and everything worked fine.
Comment: Then, you may need to retag because I think the tag "caching" is not directly related with this subject.

Blank browser after clearing the cache


Can I travel to Kuwait on a employment visa with old passport number?

Question: I have a Kuwait employment visa, with my old passport number. But as the old passport has ECR on it I got a new passport with a new passport number with ECNR. Can I travel with the same visa or do I have to obtain a new visa with my new passport number?
Answer: I assume your old passport has been canceled. In that case, you will have to obtain a new visa to enter the country again.
Comment: This is almost certainly incorrect.
Comment: I saw a query similar to that of mine,as it was stated in that to take both our passports I certainly didn't find it as a solution when I approached the agency.


Solution curves of autonomous ODE

Question: What are some defining characteristics of the solution curves of autonomous ordinary differential equations? I have difficulty figuring out which of the solution curves below correspond to that of an autonomous differential equation system.
Answer: Hint: Since a solution $\gamma:I\to\mathbb{R}$ checks $\gamma'(t)=f(\gamma(t))$ for a fixed $f:\mathbb{R}\to\mathbb{R}$ and for all $t\in I$, what happens when there are two values $t_1$ and $t_2$ such that $\gamma(t_1)=\gamma(t_2)$?
Comment: If I understand this correctly, it means that it cannot happen that $\gamma$ takes the same value for different $t$-values but also have different gradient. Because an autonomous system should be horizontally translatable. Is that correct?
Comment: Yes, but we don't even use that an autonomous system is horizontally translatable, just that is is a solution of an equation of the form above.

Solution curves of autonomous ODE


Ego struggles when creating an app?

Question: I'm curious about what sort of ego issues you've encountered when creating an app. Obviously we're all proud of our idea, but sometimes it can cloud our judgment and make us lose sight of what the goal is--UX and the user journey. Sure, it's important to maintain the brilliance of our initial idea, but also remain flexible for any necessary alterations that may need to be made.
Comment: All of my ideas are brilliant! And everyone will always agree with me. And if they don't, it's them that are all wrong!
Comment: This feels more like a business, management, or psychology question that one specifically about UX
Answer: For the UX Designer/researcher, it's not about ego. It's about the results of your user research.* I run into tons of opinions from all the other parties involved - including from the client. The best I can do is say that I observed five people performing this task in a particular way, so the app has to facilitate the completion of that task. Usually people at least give lip service to supporting users, so some of them will see my point.
*Unless you've done no user research; then design is based on opinion and assumption.
Answer: In all seriousness, it's an issue in any profession. It is important to remember, you're a cog in a process of your product development, where if you are not in sync with the process (including your target users/audience), you're a bad cog and you can be replaced.
Where there is creativity and team work, there is no space for pride and ego, as I was always told. If you are prideful, you won't learn, progress and you won't become a better designer/teacher/driver/sportsman, etc.
As someone said above, unless you do your job of user research, testing, and analysis of the results, your work will indeed be based on bias and opinions, which makes you a bad UX designer.

Ego struggles when creating an app?


Finding shapefiles of all major cities in world (National and state capitals) at sub-district level?

Question: One option is GADM. Having explored this data, while it satifies my need for some cities, its hard to find this data at such a granular level (lower than district level) for most of the cities.
Answer: A good source would be OSM and select based on the Admin level.  Downloading all the OSM data for the world would be a pain if you just want cities, but you can try the Metro Areas extract (see here),


Finishing of basic proof of Wilson's theorem

Question: I've been trying to simplify my proof of Wilson's theorem so that I can easily understand it, but I'm running into some trouble. I reached the point where I proved $(p-1)! \equiv -(p-2)! \mod p$, but I'm wondering how I can push this further. I understand that each number in $(p-2)!$ has an inverse that will cancel it out to equal 1, but is there a way of proving that $(p-2)! \equiv 1 \mod p$ in a more elementary fashion? Thanks
Comment: "each number in $(p−2)!$ has an inverse that will cancel it out to equal 1" is a great idea! Can you find out which numbers in $(p-2)!=1\times2\times...\times p-2$ are their own inverse? That is which values of $x$ such that $x^2=1$ in $\mathbb{Z}_p$? Once you you have found this numbers, the others cancel out as you have noticed.
Comment: Sorry, I'm just a bit confused by the wording. I thought the only inverses which are themselves are 1 and $p-1$? I cancelled these out already, but is there any other way I can prove that $(p-2)!$ is congruent to 1 mod p? I feel like the fact that inverses cancel each other out doesn't really stick with me yet, as the modulus operation was only introduced to us this year.
Answer: Outline to prove that $(p-2)! \equiv 1 \pmod p$ (thanks to above comment from Gio and this thread):

For prime $p$, every positive integer $a \in Z_p$ has a unique "multiplicative inverse" $x \in Z_p$, that is, $ax \equiv 1 \pmod p$.

So for each integer $a$ in 1 to $(p-2)$, which has its multiplicative-inverse $b$ different from itself, you can combine $a$ and $b$ and we will have $(ab) \bmod p = 1$.

Now we are left with integers $a$ which are their own multiplicative-inverse. That is: $a^2 \equiv 1 \pmod p$.
But that means,
$p | (a-1)(a+1)$.
Since $p$ is prime, this is only possible for $a=1$ and $a=p-1$. So, among 1 to $(p-2)$, there is only one such $a=1$.

(For Wilson's Theorem, we can directly use above arguments to say that:
$(p-1)! \bmod p = (p-1) \bmod p = (p-1)$.)
Answer: Alternative proof :
If you want another way of thinking about Wilson's theorem, here is an expeditive proof :

Check that in $\mathbb{Z}/p\mathbb{Z}[X]$,
$$X^p-X = \prod_{x \in \mathbb{Z}/p\mathbb{Z}} X-x$$
(these two polynomials are unitary, share the same degree and the same roots in the field $\mathbb{Z}/p\mathbb{Z}$)

Compare the coefficients of $X$.


What is happening to my Serrano Pepper?

Question: I recently started gardening and this is one of my first plants. Can you help me understand what's wrong with it?
Location: Souther California (warmer weather).
Plant location: In a pot, outside (5th floor if that changes anything).
Soil used is : Organic potting mix.
Watered once I see some dry soil on top.
Comment: Hi, it will help us at SO provide a better answer if you click 'Edit' and add the following information to your answer. Your regional location and current season, your soil type and growing conditions (inside in a pot or outside in soil in the garden). The "squiggly" lines look like leaf miner. Sometimes the best treatment is to wait and see whether predatory insects will visit your plant to control this disease. If that is unlikely, I'd plant a "companion" plant next to this plant, that is designed to draw the miner away from your diseased plant and instead attack the "sacrificial companion".
Comment: @andrewbuilder Thank you for the input I will add additional info to my post. Appreciate your answer.
Answer: Unfortunately, it is not an easy question to answer. There are many, many things that can cause leaves to yellow and die: overwatering, nutrient deficiencies: (magnesium nitrogen or iron), low light, diseases, viruses... you get the idea.
It really comes down to a process of elimination. What are you doing correctly and what aren't you doing? I think your watering routine is probobly fine. You live in sunny California and the plant is outside so low light is probobly not the problem. It is hard to tell based on the single picture but the plant looks rather large it might be time for a new pot, a larger pot. If your not fertilizing the plant I would suggest you start.
After giving the root system more room to spread out (larger pot) and fertilizing a bit the plant should come back.
Answer: The first point I'll make is that container gardening is completely different to gardening in soil in the ground. This fact alone took me years to understand properly. Once you can grasp that concept, pot plant and other container gardening becomes a lot easier to manage.
I'll make a strong distinction from this point onwards... soil is in the ground and growing media is used in pot plants.
Container gardening demands more time and effort and here are the reasons why...

Water - growing media in pot plants and other containers drys out far quicker than soil in the ground. In warmer climates and exposed conditions, such as your fifth floor balcony Southern California, this means a lot more water is required to maintain a healthy medium and therefore healthy plant;
Sun - balcony gardening means you often don't have a choice as to how much sun your plants are exposed to, so you may need to provide temporary or permanent shading, ESPECIALLY to the sun side of the pots (note that, space permitting, this can be achieved with other pot plants);
Direct and radiant heat - Concrete, tiles, render are all building materials that heat up during the day and then release that heat overnight, increasing the temperature variations in the growing media and increasing the top/high temperature, such that the growing media in pot plants can heat up and literally cook the roots of your plant.

The second point I'll make is that a healthy growing medium equals a healthy plant. So to bring your plant back to health, let's look at making sure you provide it with a healthy growing medium.
A good growing medium needs moisture. Container gardens need constant watering. Probably daily in your climate, especially in summer. Once the growing medium in any container has dried out completely and for more than one day, most of the soil biology is dead or dormant.
A good growing medium needs microbiology to facilitate the absorption of nutrients by plant roots. Container gardens need special attention to biology. Those essential organisms that normally "appear" in soil must be encouraged to "appear" in container growing media. Let's look at how you might achieve this...
Organic based fertilisers are essential. Well rotted / decomposed cow manure is excellent for this purpose. Spread across the top surface of the growing medium to a depth of about 0.5cm / 0.25 inch. A light sprinkling of pelletised chicken manure is also good, once the plant is well established and growing strongly (but remember not to do this when you have visitors - the smell is unpleasant).
Soil amendments help. A light sprinkling of granular potassium sulphate is valuable for plant cell growth.
A thick layer of mulch is essential. If you can procure some pea straw or lucerne / alfalfa hay, use a 2.5cm / 1 inch layer of this material across the surface of the potting mix as a mulch. At worst, a thinner layer of lawn clippings will suffice. Mulch is like our skin - just as our skin protects us from the elements, mulch protects the microbiology in your growing medium from the elements.
Liquid tonics are essential. Every two weeks in summer and every four weeks in winter, apply a liquid seaweed mixture as tonic for your container growing media. This tonic will help feed the soil microbiology, which will in turn help feed your plants. If you can procure worm castings (worm poo), this material mixed into the liquid tonic will make a substantial difference.
As Rob mentioned, a larger pot also helps because the larger volume of soil:

retains essential moisture for longer periods of time;
takes longer to heat up and cool down, thereby providing a more consistent soil temperature;
provides greater volume for root growth in the growing medium, which in turn can support a greater amount of plant growth above the growing medium.

What is happening to my Serrano Pepper?


Will my characters still be on WoW after many years of not playing?

Question: I haven't played WOW for maybe 8 years or so. My subscription would have ended about the same time. If I resubscribe and download WoW again will I be able to start where I left off with my old characters or will I have to start from scratch? I managed to sign in after resetting my password and the status of my account is BANNED.
Comment: Do you know why your account was banned?  If not, contact Blizzard's support to see why / if they can lift this ban
Comment: Second on this.  If your account was unprotected for the past 8 years, there's a possibliy that it was used by RMT groups to create bots/spam ads.  Your characters may have been deleted by them in that event.  Check with Blizzard Support about the ban first.
Comment: The hilarious part about this is the fact that botters / spammers can even *get into* the account after 8 years of inactivity.
Comment: @Dropped.on.Caprica They probably didn't wait 8 years.
Answer: Call Blizzard support. There are lots of reasons why an account can get banned (unless of course you broke the rules yourself then you know the reason) for example, they will ban accounts that get compromised, but if you can prove it's really you this time, they can unban and reactivate your account. Banned account does not mean that characters are deleted. I've known several people who came back to WoW after many years to find their stuff gone and/or accounts banned, and a call to Blizzard support fixed it all up for them.
Answer: Characters are not deleted for inactivity, even when the account is banned. Here's a link to a WoW forum thread discussing the topic: http://eu.battle.net/wow/en/forum/topic/7339045392

Characters that are on an inactive account for a long time, may get renamed (to free it up for someone else) but whilst Blizzard reserve the right to delete characters, they have not yet enforced this right.

I recommend contacting player support. You'll probably find that your account was commandeered by a gold farmer/botter and was banned that way. I've had my characters still around even after long periods of time.
Answer: No. If your account was banned, you cannot access those characters as long as the account is banned. If you are able to contact Blizzard support and have the ban reversed, it may be possible to recover the account and characters.
Answer: If your account status is banned, you'll need to resolve that before you'll be able to log in.
Blizzard does not delete characters - all your characters will still be around.  However, those characters will probably need new names:

Any characters that have not logged into the game since December 7, 2010 will have their names freed up, making them available to anyone creating a new character or using the paid Character Name Change service.

http://us.battle.net/wow/en/blog/15910697/release-the-names-character-name-reclamation-coming-6-18-2015


ZF2 - Check referer in API call

Question: I want to write an internal REST API which returns some json data. How can I protect that API call, that it only can get called by the same domain? Should I do it with a dispatch listener?
Thanks!
Answer: You could indeed create a guard (an event listener). You can have a look at BjyAuthorize to see how it's implemented there: https://github.com/bjyoungblood/BjyAuthorize/blob/master/src/BjyAuthorize/Guard/Controller.php
Other than that, I'm not sure but how about trying server things? Like Same Origin Policy or CORS headers?

ZF2 - Check referer in API call


how to save files in live usb when running live ubuntu

Question: my system doesn't have a hard disk, so I am using a USB stick of 16gb. I am running live ubuntu without installation, it's taking about 3 GB of space. is it possible that can I create a partition for USB so that I can save files in USB when using live ubuntu at the same time?
Answer: I also tried a lot to do this. Actually there is a term for this called "persistence". In my experience, it works only when I create the bootable usb drive with Rufus. In Rufus, when you are creating the bootable usb, there will be an option to set persistence and the size of the persistent partition. It will make the live boot slower but at least you will be able to save your changes.
(edit: Hi, I think I misinterpreted your question. If you just want to store some other files on the USB Drive, you can simply create a new folder in the USB Drive and store them, (you might not be able to use them while you are in live boot) but if you want to store files which you can access in the ubuntu during live boot and also want to save other software installed in ubuntu, then you should make persistent partition in Rufus as I told earlier )
Comment: If you do that with Ubuntu however, be very mindful that all versions prior to Ubuntu 19.10, including the most recent 18.04 LTS refresh, have a major [BUG](https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1489855) that prevents Ubuntu from booting when the persistent partition resides on the same drive. So you need to make sure that you use Ubuntu 19.10 or later.
Answer: In at least 18.04 live boot, it permits plugging in a second USB, which shows up promptly. I was then able to drag and drop files from the failing hard drive to the second USB.
Answer: Make Sure You Activated it Because it Came 0 Gb By default And 0 Means thats the persistence is desactivated.
There is it.
strong text


SSH host keys vs. certtificates

Question: I'm struggling to understand what the difference between SSH host keys and certificates is. When to use which ? How do they differ?
Answer: With an SSH host key the client has to already trust the host or has to accept the fingerprint on the initial contact - of course only after validating that the fingerprint matches the expected one. When using a certificate the host key is instead put inside this certificate and the additional features of the certificate like subject, issuer and signature of the issuer make it possible to derive trust into an yet unknown host key from trusting the issuer. It also makes it possible to have a limited life time of the host key and to revoke it. Essentially using a certificate makes using a PKI possible which make everything more scalable.
If you understand how certificate validation works in the browsers you can also compare it to self-signed certificate vs. CA issued certificates: the simple host key is comparable to a self-signed certificate, where one explicitly needs to add the trust to each browser. The host key inside a certificate together with a PKI is instead similar to the CA issued certificates we have in almost all cases when accessing a https-URL. In these cases the trust in the server certificate is derived from the trust in the root CA's located in the trust store of the browser or OS, i.e. only these root CA needs to be known up-front but not each server certificate.
Comment: @adam86: there is a difference in format between having the  key in SSH host key format and having the key wrapped inside a certificate. But there is not really a difference in functionality.
Comment: But what when I use self signed certificates? Is there any difference (for example in the format?)
Comment: Thank you. So basically you use either a host key or certificate, you can't both, right ? And also, similarly to HTTPS, this cert / key is used to authenticate the server we try to connect too, right ?
Comment: @adam86: yes and yes.

SSH host keys vs. certtificates


Custom related for arrival from Paris to Vancouver via Montreal

Question: My grandson is returning home to Vancouver from Paris via Montreal , all with AC. Does he have to pickup his suitcase in Montreal and go through
Customs or can he check in his luggage directly to Vancouver . He is 14years old and I would like to give him the correct information.
Answer: Yes he does.
Everyone entering Canada has to clear customs at their first point of entry. In this case it is Montreal.
Your grandson's flight from Montreal to Vancouver will be a domostic one, and there will be no customs facilities at the end of it.
Answer: DJClayworth is right but that is only true if you are changing planes. I have personally done this flight before and we were not allowed to disembark in Montreal at all and so we didn't even have a chance to pick up our suitcase but this was a decade ago (Monday, September 7, 2009, AC885, seat 32A). Here's a forum post about this. So: your grandson needs to ask Air Canada in Paris how the connection is going to happen. Or you can let us know the flight number(s) and we can check.


Replicate Integrations after sandbox refresh

Question: I have a full sandbox that has a few integrations with 3rd party vendors like lexis nexis, onespan, mainframe core(informatica updates), community portal. We want to refresh the SB from prod and then ensure these integrations are rewired and work as before. Can you advise on which is the easiest way to make a copy before refresh and be able to get those settings back after refresh. What would need be done on my side vs other vendors side. Thoughts appreciated !
Comment: There is no single answer for this, since some integrations require actions on external system side to re-establish the connection or do special configuration, while others may require manual changes to settings based on domain name et.c
Answer: As a best practices, It is suggested to document existing integrations with external systems like lexis nexis, onespan, mainframe core etc., and
make sure the endpoint URLs, credentials, etc. are all updated. These values are typically saved in the Custom Settings, Custom Metadata Types, and Named Credentials.
Below are few check points.

What are the integration channels in place.
What are the credentials used.
Is the Connected App used.
Which Salesforce API is used.
How would two-side teams collaborate in the entire refreshing time
period.
How to switch the integration endpoint from production to test
environment.

Also, check Sandbox Setup Considerations and you might have few limitations like Copying Connected Apps setting etc.,  and you need to have post migration activities document checklist.
Check sandbox refresh best practices here.
There are few good 3rd party tools like Gearset, Flosum, Autorabit, Copado, Bluecanvas etc., to automate salesforce deployment activities on point and click interface.
Comment: Thanks for the response


Debye temperature for the steel?

Question: I'm looking for data on Debye temperature of steel (ideally with a known carbon concentration, structure, and set of phases), but find only data on elements. Do You happen to meet the data in papers, or textbooks?
Comment: Perhaps here?   https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCsQFjAA&url=http%3A%2F%2Fwww.springer.com%2Fcda%2Fcontent%2Fdocument%2Fcda_downloaddocument%2F9781441999788-c1.pdf%3FSGWID%3D0-0-45-1326037-p174117366&ei=MHLBUrHmAq7LsATHmoGQDg&usg=AFQjCNGMQIYKUe0dFWRW4PeKa9Be7xbzZw&sig2=Amux9F7pHJJcHKx1_HRGsA
Comment: @CarlWitthoft: It's number two hit by google searching for "debye temperature of steel". Of course I tried that. No the doc doesn't have debye temperature of steel. Nor any doc on first n pages of the search.
Comment: @Alexander: third google's hit of "debye temperature of steel" is a wikipedia article: [Debye model](http://en.wikipedia.org/wiki/Debye_model) -- and there's no such information there. Can You give a link?
Comment: @Alexander: I saw this doc, and even read the table, but missed the part that the some of the alloys listed are actually stainless steels. Please make it an answer so I could accept it.
Answer: The Debye temperatures of some steel alloys can be found in the thesis of Rajevac, Vedran:
"Lattice dynamics in Hydrogenated Austenitic Stainless Steels and in the Superionic Conductor Cu 2-δ Se" on p. 43.

In general searching for material specific data I recommend starting with a search in Google, Google Scholar and Landolt-Boernstein. If neither turn up anything it might still be an open research question.
Answer: J Phys Condens Matter. 2010 Feb 10;22(5):055402 :
"The Debye temperature, Θ(D), of Fe(100-x)Cr(x) disordered alloys with 0 ≤ x ≤ 99.9 was determined from the temperature dependence of the centre shift of (57)Fe Mössbauer spectra recorded in the temperature range of 60-300 K. Its compositional dependence shows an interesting non-monotonous behaviour. For 0 < x <= ~ 45 as well as for ∼ 75 ≤ x ≤ ∼ 95, the Debye temperature is enhanced relative to its value of a metallic iron, and at x ≈ 3 there is a local maximum having a relative height of ∼ 12% compared to a pure iron. For ∼ 45 ≤ x ≤ ∼ 75 and for x ≥ ∼ 95 the Debye temperature is smaller than the one for the metallic iron, with a local minimum at x ≈ 55 at which the relative decrease of Θ(D) amounts to ∼ 12%. The first maximum coincides quite well with that found for the spin-waves stiffness coefficient, D(o), while the pretty steep decrease observed for x ≥ ∼ 95, which is indicative of a decoupling of the probe Fe atoms from the underlying chromium matrix, is likely related to the spin-density waves which constitute the magnetic structure of chromium in that interval of composition and show also anomalous dynamic behaviour. The harmonic force constant calculated from the effective Debye temperature of the least Fe-concentrated alloy (x ≥ 99.9) amounts to only 23% of the one characteristic of a pure chromium as determined from the heat capacity experiment."
And the Debye temperature of iron is about 470K.
Comment: I found data on AlTi and many others, but not the steel. Which is very strange, given that steel is the main construction material for some hundered years or so, and it's Debye temperature gives us idea about the ratio of electron to lattice thermoconductivity at the given temperature.
Comment: Yep, one expects non-linear behaviour of Debye temperature as a function of concentration. Although not as drastic as 77% reduction due to 0.1% of Fe in Cr. That's really something.

Debye temperature for the steel?


.Net MVC3 resource file and multi-tenancy

Question: I have learned much and solved a lot of problems coming up with multi-tenancy.
But one problem still exists. I have to offer a tenant-specific resource file because our customers want some text a little different then other customers.
Is there a way to implement a multi-tenant resourceManager? I haven't found anything else in the www.
Answer: We needed the same functionality in a web forms project and ended up implementing our own IResourceProvider, finding inspiration in http://msdn.microsoft.com/en-us/library/aa905797.aspx. That way we could have files like Default.aspx.rex, Default.aspx.da-DK.resx and Default.aspx.da-DK.xyz.resx, where xyz was the customer name. This worked quite well. Going this way seems to imply using the App_LocalResources and App_GlobalResources folders.
However, those folders are not the MVC way of using resources and will cause problems. For instance, they will not work properly with unit testing. As a last resort you might find it useful though.


Create namespace for the code pushed from dev org to prod org

Question: Currently I am developing in a fresh dev org with no namespace created. I want to push this code to another dev org with namespace already created. How I can push the code with namespace included( Both apex and lightning ). Do I need to change manually or any other ways available?
Answer: You would push it just like normal. Changeset (not possible if orgs are not connected), IDE, ANT, etc.
Once it is in the org it will take on the namespace.
Are you running into any issues? If so please be more specific and you will get a more specific answer
It all comes down to the basics, pushing code or metadata is no different than creating it manually.
Comment: I can push the code using ANT tool. But Namespace is not created automatically. So, while packaging the test class throws error for field accessibility
Comment: Not to the code no, but to the field API names yes it will be. The code does not need it as everything in the org with the namespace is "local" despite the namespace. If you are packaging then when you package it will be added to the code
Comment: I tried packaging also (both beta and released), but no namespace is added to the code.
Comment: @scsiva1991 - It is in the package. Your local code will not be updated
Comment: it is in the package means, How can i check the namespace is added since we took managed package
Comment: Its *magic* - It just happens. Install your package and test it to see it work. Trust the process. https://salesforce.stackexchange.com/questions/13353/dynamic-soql-queries-and-managed-namespaces
Comment: What makes you think it's _not_ being added?


resizing photos from a custom size option

Question: I have an old antique photo that I need to resize for printing from a printing shop, howerver, how do I resize a small 5x7 cm to a large , 20x20cm after being restored.I dont want to have the photos be compromised by the quality . thanks
Answer: How is the image being restored? If you're scanning a print, transparency or negative, then you're best getting the scan at larger than you think the print will be, and using that size to do any retouching required.
Depending on the original, things will look however they look. Just make sure you get the highest quality scan possible (highest quality in terms of scanning operator and scanner, not necessarily in terms of biggest file size).
If you need to scale up the image (you shouldn't), then do this as the first step, and scale to an exact multiple, if you can (200%, 300%, 400%), even if that means the final image is slightly higher than 300DPI for your purpose.
From there, retouch as required and output as a print when done. It's probably a good idea to keep the original scan file, just in case you realise you made a mistake with some of the retouching.
Hope that helps.
Answer: You probably realise this, but it's worth stating: if you need a rectangular 5x7 cm photo to fit a square 20x20cm final image, you're going to have to resize it proportionally to 20cm x 28cm, then crop the image down to a square, to prevent distortion.
(The exception would be if you use Photoshop's content-aware scaling, or other heavy retouching, but you'd still have to chnage the shape of your image).
Answer: The best way is to click its picture by canon camera in high resolution, this can be nearly good image after resizing. I hope so.....
Comment: Hm, are you sure that can work? Can you give an exaomple with some screenshots showing the way to get a result? That is an factor 4 the image should be enlarged. As far as I know you can do factor two safely, greater enlarging usualy results in pixelated resulting images ... Depending on the used image a way enlarging a little bit  and correcting the image  and doing this several times can result in a better result, but that depends on the used image and the software used to enlarge it. I do not know if Corel Draw is able doing that ...
Comment: You can check it.


Centring letters in circles

Question: Are there any rules for centring lower case letters like a 'd' in a circle? To me it doesn't look right unless it's moved more to the left but then it's not in the middle.
Answer: Adjust it manually until it looks right, and feels balanced. Eyeball it!
For example, this is my guestimate.

Draw an inner circle as a guide if you have difficulty doing it visually, or if you want to check it.
Comment: Since the d is heavy in the bottom I would even nudge it a tiny bit up to compensate. But if several letters must be placed in circles they need to have the same vertical position, so the best compromise must be found. If for example an o also should be placed in a circle it could easily look like it was too low and the d might have to be placed even higher.
Comment: @Wolff -  absolutely! The point is to adjust it until it feels right. I don't really think this can be quantified or measured accurately, an inner circle as a guide can help, but every person will see it/feel it a little differently.
Answer: Centered inside a circle becomes objective (=not an opinion)as soon as there's a common agreement how to measure it. Unfortunately no common agreement exists. Artists place items as they like.
Drawing and layout programs have buttons for alignment principle "let the bounding boxes of the objects have the same centerpoint". That idea doesn't satisfy you, I guess.
Some time ago a GDSE user had a little resembling problem with a logo. He accepted one easy centering principle that you can try, too. It's here: How could I make a logo that looks off centered due to the letters, look centered?
Totally another idea is to move the letter so that it's center of mass is at the circle center. The center of mass is the average coordinates of the colored pixels of the letter.
The center of mass can be determined in several ways. The easiest way is to use a CAD program or Inkscape which have a ready to use function for it. The next example is in Inkscape.
The starting point is  an Arial d which is 25 mm high and 15,5 mm wide. It's converted to path (=Path > Object to Path) and ungrouped:

The centerpoint cross is in the middle of the bounding box like normally in drawing programs.
Extension Visualize Path > Measure Path > Center of Mass inserts a new cross into the center of mass. It's a new object:

In the next image the d is centered with the circle in 2 different ways:

In the left the bounding boxes have the same centerpoint. The d and the circle are simply aligned horizontally and vertically.
In the right the d has the center of mass inserted and the circle center is at the same place. The midpoint of the circle snaps to the center of the inserted cross if you move the circle and have snap to midpoint =ON.
The centering idea "same centers of mass" can look wrong because it clashes with "as big gap between the parts in all directions". See the next example:

In the left the centers of the bounding boxes are same (=normal vertical and horizontal alignment)
In the middle centers of mass are same
A fix is to make a combination. The d is moved downwards by applying align horizontally. There's still L-R balance of masses.
Answer: Conceptually this is about aligning 'optically', rather than aligning 'mathmatically'. I.e so it is perceived as being centered ( inspite of the bounding box not being in the dead center )
Also you could raise it up a bit higher in the circle - i think you want to create perception of tension,like the 'd' is being suspended, and not falling down.

Centring letters in circles


Function of Pass through port on Access Point?

Question: I have an Alcatel Access Point 1201H which has got 1 uplink gigabit port while 3 downlink ports. Also there are two ports named "PT" which mean pass through ports. I want to know what is this port used for?
Comment: Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
Answer: The Pass Through (PT) port is used for giving access to another device without switching. A good example would be an analog telephone line. The port is active, even though the access point fails.
If there are two cables in a wall jack, one for providing connectivity to the Access Point and a second one for some other purpose and it needs to be guided out from behind the Access Point, the Passive Pass-Thru port on the AP can be used for this purpose.
The AP is designed for hotel rooms, dorms, classrooms etc.


Likelihood ratio test

Question: Is the likelihood ratio test ($-2 \log L$) basically like the partial F-test in that you are using it for logistic regression instead of linear regression?
Answer: For logistic regression you use the asymptotic distribution of the log of likelihood ratio test statistic for variable selection (testing hypotheses or model selection).  In the case of linear regression, due to the assumed normality for the error distribution, there is no need to use asymptotics, and the likelihood ratio test static trivially reduces to a ratio of chi-squares, that is, F-distribution.
Comment: *...and the likelihood ratio test statistic trivially reduces to* ***(through a nonlinear transformation)*** *a ratio of chi-squares...* :) (Note also that *static* should be *statistic*) :)
Comment: Also, this is *very* (!) picky, but the $F$-distribution is, as I know you know, not *quite* a ratio of (independent) chi-squared random variables. :)

Likelihood ratio test


Is this yellow substance on my chicken meat a fat deposit, and is it ok?

Question: This was a Plymouth Rock chicken from my own yard, the first one to be eaten, hopefully. I am not sure about this yellow substance. Is it just fat deposits? Is it normal, and should I just remove them?
Comment: This is a beautiful piece of meat, from a well treated animal. Enjoy it!
Comment: It just means your chicken eats naturally and is not fed only grains or pallets.
Comment: Highly related: https://cooking.stackexchange.com/questions/108939.
Answer: According to this website (linked below) yellow fat is a good thing! Says it's

"the result of a grass-based diet which is high in chlorophyll.
The cartenoid beta carotene in the grass is the same as the orange colour found in carrots. This is what produces the yellow fat in chickens as well as the bright yellow yolks in pastured eggs."

https://www.dirtycleanfood.com.au/blogs/unearth/why-is-our-chicken-fat-yellow
Comment: @theonlygusti a little ironic but Stephie's link does say "Do not copy the complete text of sources; instead, use their words and ideas to support your own. In particular, answers comprised entirely of a quote (sourced or not) will often be deleted since they do not contain any original content."
Comment: Please **do not post answers that consist exclusively of copied text** and always *mark* the copied contents clearly. See [here](https://cooking.stackexchange.com/help/referencing) for the rules.
Comment: Had the quote in quotes with a link. Only other thing was author, which isn't stated in the article. So that's the website. Which is in the URL.
Comment: *Strictly* speaking, this answer could be deleted as it is not primarily your work. I will keep it for now (as an explicit exception), as it's _information_ is correct and helpful. Please remember that for future answers.
Comment: @Stephie where is the rule that says such answers can be deleted?
Comment: **Comments have been [moved to chat](https://chat.stackexchange.com/rooms/144944/discussion-on-answer-by-j-chant-is-this-yellow-substance-a-fat-deposit-and-is-i); please do not continue the discussion here.** Before posting a comment below this one, please review the [purposes of comments](/help/privileges/comment). Comments that do not request clarification or suggest improvements usually belong as an [answer](/help/how-to-answer), on [meta], or in [chat]. Comments continuing discussion may be removed.
Answer: Home grown, free roaming, chicken can be recognized by those yellow deposits of fat, and by its meat being more firm to the bite, due to the muscles being actually used during the roaming.
Source: I have grown up in a family which used to keep some chickens for laying eggs and then butcher them when they were no longer productive.
The butchered chicken was never as pale as the one we would buy from the local butcher, its fat was never white but rather yellow and, once it was grilled, biting away the flesh from the bones and chewing it needed more effort. But also the taste was way better.
Comment: I've bought chicken with these yellow fat deposits in the supermarket but yes, having these is a sign of a high quality chicken that lived a (relatively) happy live.
Comment: @PiotrGolacki it was better
Comment: Was the taste better or worse? It's not clear.
Answer: Poultry and beefs fat get a tinge of yellow when the animal was fed it's natural diet. When livestock are only fed corn then that high-protein powder gives the animal white fat.
Generally, the diet of animal is made clear in the taste of the fat. A lamb from the semi-desert landscape of the Karoo takes to the taste of the desert pepper-bushes.
The lambs from the grasslands of the North-West province have a much milder and agreeable taste to there fat.
In general practice you will not see the yellow fat often, because corn base diets of livestock brings them to slaughtering weight much quicker.
In the case of beef it is difference between tending to an animal for three years or tending to it for five years before you get money for it.
With the margins in poultry farming being so razor thin, you will not get yellow fat from anything but the highest quality of free range poultry.
There is a growing movement in South Africa where people are getting more involved with how the food they consume is produced.
More and more people are willing to pay extra for grass-fed beef and yellow chicken. It is good to see. Your body is your temple. You should not pollute it with anything like a battery chicken.
Comment: May I suggest emphasizing the degree of yellowness? All the chickens I've ever bought have had yellow fat, possibly due in part to getting things like marigold petals in their feed, but none have had fat that's as deeply yellow as the OP's photo shows.
Comment: -1 for making improper generalizations. The question wasn't about lambs. In chicken, 1) corn is not an unnatural diet, and 2) corn is what makes it yellow, and is considered a sign of quality. See also https://cooking.stackexchange.com/questions/108939.


Where does an access network begin and end?

Question: My book's definition for access network is "a network that physically connects an end system to the first router (also known as the "edge router") on a path from the end system to any other distant end system". However, the figure below(access networks highlighted in blue) seems to indicate that the network extends beyond the first router, which is at odds with the definition at the top of the page. Is the diagram or definition wrong? How can you reconcile the two?
Comment: I do not see your problem. Look at the gray, hose-shaped box title Home Network. That is the access network. I do not know who wrote the red circle, but that is incorrect, and it does not appear to be an original part of the book.
Comment: @RonMaupin I added the circle for emphasis.  I just can't reconcile how the definition mentions an access network "connects the end system to the first router", but in the diagram, the blue line that represents the access network goes beyond the first router. Shouldn't it stop at the first router?
Comment: It does go to the first router of each site in each highlighted area. I do not see what the problem is.
Comment: @RonMaupin I think we're looking at different parts of the figure. I added a second photo to the original post to clarify. Why does the blue line(that represents the access network) go through the first router and all the way to the second router? Shouldn't the blue line just stop at the first router? That's the case with the other examples in the diagram, like the cellular network - the blue line only goes to the first router which is consistent with the definition at the top of the page.
Answer: There may be further information about Figure 1.4 in the book itself. There may also be supplementary information in an associated publication such as a study/class guide or downloadable supplemental materials - maybe even in the teaching materials. If not (or you don't have access to them), I see one of two different explanations:

This is an error. Today, publishers often post errata for books on their website. I would check to see if such exists and if it mentions this issue (and others that may throw you as you work through the book).
It is intended this way to show that each home has an access network, but those homes are also in themselves ultimately a single client on the ISP access network. Put another way, from the ISP perspective each home is a client attached to their access network.
Answer: The blue line is a connection. The home router is connecting to the ISP router. The home router is the first router in the home, so it is the edge router for the home. The router to which it connects is a router at the ISP, and that router is not part of the home network, it belongs to the ISP network. The home router must connect to an ISP to access the Internet. The home network could change to a different ISP, and the line will then connect to a different ISP router. The ISP router is not part of the home network; it is part of the ISP network.
Answer: First router connecting to access point is  consider as access -link . Access point is considered as end devices in this topology ..
Access networks begin from first router interface towards access -point


North-South Satellite Manuever

Question: I am doing North-South manuever for GEO satellite. My purpose is to reduce the inclination. My initial inclination is 0.07 deg, and my target inclination is 0.0002 deg. I have tried the maneuver in GMAT. I tried to do maneuver in ascending node and descending node. Both of them seems work. But I still confused, should I do the maneuver in the ascending node or descending node?
Thank you.
Comment: the node closest to apogee should be more fuel efficient, but both will work
Comment: thank you very much for your answer. I found the value of dV (deltaVelocity) was a little different between both of the node. Now, I understand the reason. Thank you.
Comment: It's always okay to answer your own question. If you think you have a solution I'd say go ahead and write it up as an answer. That way future readers will benefit.
Answer: Although it has been already answered briefly, I would like to add some extra information (increasing the inclination) about on the N/S maneuvers.
Well the location of the thruster firing is highly depends on the maneuver type. If the maneuver is:

North, then you should fire your thrusters while the satellite passes from ascending node in order to do more efficient maneuver. Since satellite already starts to ascending, less fuel will be used.

If it is:

South, then you should fire your thrusters while the satellite passes from descending node in order to do more efficient maneuver. Since satellite already starts to descending, less fuel will be used.

Basically with this approach, you will not waste your fuel and you let part of the job to do by orbital mechanics (celestial mechanics).
Comment: It's definitely not true in the case of the maneuver the asker wants: to decrease orbital inclination. Burning north at the ascending node, or south at the descending node will increase orbital inclination.
Comment: Hmm... this is interesting but is it true? Can this be supported with links or sources or mathematics? *Thanks!*
Comment: Well yes you are right! I just wanted to add extra information about the N/S maneuvers. But question is emphasizes to reduce inclination, so the most efficient time to perform maneuver where the satellite is slowest. Thus the place needs to be close as much to apogee.
Comment: The problem probably refers to a circular orbit, so there won't be an apogee.
Comment: There is no perfect circular orbit (even though the GEO satellites are have an eccentricity like 0.00000xxx) in the universe. I know it is very close to "0" but it is NOT "0". So even the GEO satellites are have apogee and perigee. Of course it is up to you to add this very small eccentricity in your calculations but it is highly depends on your mission and wanted resolution. For example T4A has the 35781 km perigee and 35808 km apogee even it is a GEO satellite that I worked with. In our case it was very crucial to add those numbers into our calculations.
Answer: You can get the same efficiency in the ascending or descending node, it's just that you would need to apply the force in the opposite position if you wanted to switch from ascending to descending and vise versa.
Comment: This seems like the right answer to me; the definition of which node is ascending and which is descending is arbitrary; in this problem there's complete symmetry about the equator.

North-South Satellite Manuever


How to make soy/ fish sauce spread over rice?

Question: When cooking stuff like fried rice, I often run into a problem that the sauces don't really mix throughout the rice, rather just attach themself on a small bit of it. Any way I can fix this?
Comment: I'm surprised by this question. Fried rice is a stir-fried food, so the conventional method automatically takes care of mixing the ingredients really well. Can you describe your method in detail?
Comment: I don't have a wok, I cook in a pan @rumtscho
Comment: I've never had this problem, but I use a bottle with a small opening  to shake an amount on, moving around as I go so it's not just all in one place, then stir
Comment: Note in Chinese tradition, _how_ the liquid seasonings are added, courtesy of [Chinese Cooking Demystified](https://youtu.be/_hkG0e13HKM?t=406).
Answer: As mentionned. The answer is probably just stir it more. Martin Yan often quoted.... "It's stir-fry, not sit-fry".
That said, if you want to distribute it more without changing your salt:rice ratio, you could thin it out with water (I'd start small; a tablespoon or two) or low-sodium broth. That'll ensure more of the "sauce" gets spread to various grains. If your heat is right, most of the water should evaporate pretty quickly, while you stir your rice.
Comment: Instead of water, you could also use mirin… it's a sweetened alcohol made from rice, and can enhance the rice flavor.  (I often use it in stir fries if I need to thin things out)
Answer: While fried rice is cooked with almost constant motion, as mentioned in the comments, I'll add that you can successfully make fried rice without a wok. In either case, to ensure proper mixing, you also want to be careful not to overcrowd your pan.  Too much rice will not only make it harder to mix, but will also make the browning/frying more difficult to achieve. It also helps to use day-old rice, or rice that has been refrigerated.  This cold rice is less susceptible to breaking apart when you mix.  So, the key, in general, is to mix well.
Comment: Those are good poitns, but it seems still like a logical impossibility to me. How can such a small liquid coat evenly such a large quantity of lfie
Comment: You are not covering each grain of rice with fish sauce.  It is a seasoning and flavoring that combines with the other ingredients as you are mixing and cooking. If you are not getting enough fish sauce flavor for your liking, you can also use it on each serving as a finishing seasoning.
Comment: What do you mean by "combining" other than "coating"?
Comment: All of your seasonings and flavors will combine with mixing and heating.  From your initial post it sounds like you are not mixing enough, thus my tips.