What is the benefit of overnight oats compared to traditional oatmeal cooking methods?

Question: The primary advantage I hear people talk about is that overnight oats take "little prep time", but isn't that true of oatmeal anyway? Is it just a fad because it's something different and you can use a mason jar? Or is there a true reason or benefit to overnight oats compared to traditional cooking methods, particularly quick oats?
Comment: Not using quick oats is a big plus, flavorwise, but that's *opinion.*
Answer:
They taste different. Some people like the taste of "overnight oats" better than regular oats, and some people absolutely hate them.

"Put a bunch of stuff in a jar and leave it" is simpler, for some, than cooking oats on a stove (or even a microwave).

Overnight oats prep happens at night, at which time many people are less rushed than in the morning, when oatmeal is typically eaten. I, for one, would not have time to cook oatmeal in the morning, but I definitely have time to prepare overnight oats the night before and throw it in my bag before leaving to work.

Not everyone has a way of cooking oats at the place where they usually eat breakfast. I suppose you can eat traditional oatmeal cold, but likely many people would prefer overnight oats to traditional oats for eating cold.
Answer: Using the overnight method for oats is more beneficial for oats that aren't quick oats.  For example, steel cut oats can take ~20 minutes in a pressure cooker, then there is still the prep time to add all of your ingredients.
Using the overnight method, you can just dump everything and let it soak overnight.  The total amount of work is lower.
The bigger benefit, though, is that you can prepare a breakfast meal the night before or even days in advance, and have a ready to grab meal.
Comment: "days in advance" - how many days in advance could you make overnight oats?
Answer: To add on to the answers above, for folks who work in an office, having something that can be easily taken to the office to be eaten at one's desk is a benefit, and that's easier if there's absolutely no morning prep time and you don't have to worry about cooling it in order to transport. You can make a big batch and break it up into small servings, whereas if you did that with normal oatmeal you'd still have to have a way to reheat it to eat. And if you do that and make the oatmeal in the jar or whatever it will be stored in, there's only one thing to clean instead of two (bowl + pot you made it in).
Plus, if you live in a place where it's hot outside at least part of the year, cold breakfast can be nice. At least in the US, the classic cereal + milk breakfast is cold, too, so this can be a nice replacement for that, temp-wise.
Answer: Another benefit of soaking is the reduction in phytic acid.
Soaking helps reduce the phytic acid present in oatmeal, which can help make oats easier to digest for some people. Phytic acid in larger quantities can blocks the absorption of certain minerals into the body.
This is partly why people soak beans overnight as well.
Here's some more background:
https://www.bobsredmill.com/blog/healthy-living/5-reasons-try-overnight-oats/ (general benefits of soaking oats, including phytic acid reduction)
https://www.healthline.com/nutrition/phytic-acid-101#in-food (background on phytic acid)
Comment: It is best to add the information contained linked resources because if (when) the links change the information becomes unavailable here.


How to build a synchronous boost converter with an IR2104 MOSFET driver?

Question:
Does anyone know how to build a synchronous boost converter with an IR2104 MOSFET driver?
I am a beginner and I have no idea how to connect the circuit, the placement of inductor and capacitor especially. The boost converter is meant to step up 12 V to 24 V. Any help would be much appreciated.
Comment: This is not a good project for a beginner, but if you must, use Andy's schematic. Do you really need high efficiency? Do you really need to control it with the MCU? Two typical mistakes: 1) under-sizing the inductor. A little inductor that looks like a resistor, won't usually work. You need to understand the equations so your inductor current is less than the saturation current. 2) be sure to put a load on the output; open loop with no load, these can produce very high voltages and will fry your parts.
Answer:
Does anyone know how to build a synchronous boost converter with
  IR2104 mosfet driver?

and...

Any help would be much appreciated.

It's going to look something like this: -

Q2 charges the inductor from the main power rail by shorting it to ground and, when Q2 releases, Q1's diode will push the stored inductor energy into the load capacitor rapidly followed by Q1 turning on properly to act synchronously.
Be careful with this - if you have Q2 active for too long, the inductor might saturate and, on some supplies you might get Q2 burning.
Comment: To increase the output voltage, the duty cycle increases but it becomes rapidly non-linear and difficult to control manually.
Comment: Thank you Sir. It now makes a whole lot of sense. However, in order to increase the output voltage, does the duty cycle has to be reduced so Q2 will have longer ON time to charge the inductor ? As I noticed whenever I increase duty cycle, the ON time of Q1 appears to be longer and ON time of Q2 is shorter.


Does the Lightning Network have an equivalent to "Proof of burn"?

Question: Is there a provable way to "burn" a single satoshi for example?
Answer: The Lightning Network is just a collection of two-party agreements on the latest channel state, and these agreements are represented by pre-signed force-close transactions which pay each party their own respective channel balance.
One way of "burning" coins then would be to negotiate a new channel state that includes an extra OP_RETURN output with the burned amount (I'm not sure if the current LN specification allows that, but there's nothing technically preventing it). However, until a channel state with this OP_RETURN output gets settled on the blockchain when the channel is closed, the two channel parties can undo the "burn" if they agree on a new channel state without it (and there's probably no reason for them not to), so this proof of burn cannot be relied on by any third parties.
Answer: There is no way, because to provably burn coins you use scripts such as OP_RETURN, which are quite like saying "I announce that these coins are unspendable".
You don't announce anything when making a lightning transaction, other than the new state to your fellow partner exclusively. It's the same reason why you can't have things such as NFTs off-chain.
Comment: @JonathanCross, that isn't provably unspendable. It's part of the UTXO, and in fact, there are about 2^96 valid private keys that can unlock these outputs. But, indeed, there are ways to provably burn coins without the ``OP_RETURN`` script, just by sending coins to nowhere as it happened with transaction "5bd88ab32b50e4a691dcfd1fff9396f512e003d7275bb5c1b816ab071beca5ba".
Comment: Coins can be provably burned without any `OP_RETURN` or anouncment -- just by sending them to a provably unspendable address like the [1BitcoinEaterAddressDontSendf59kuE](https://www.blockchain.com/btc/address/1BitcoinEaterAddressDontSendf59kuE).
Comment: Thanks, you are correct, 1BitcoinEaterAddressDontSendf59kuE is "highly unlikely to be spendable".  I suppose we could do even better with a Taproot (SegWit v1) address?


Math to calculate percentage of ERC20 balance?

Question: I'm trying to implement staking into a project. Lets say my contract has a balance of 1000 erc20 tokens, which during the calculation is actually 1000000000000000000000 because of wei. If i know user A has provided 255 of that 1000, user A is entitled to 25.5% of any profits. Lets pretend the profits are also 1000 eth of an erc20 token. How do I represent 25.5% since solidity only uses integers, and how do i then send 25.5% of 1000000000000000000000, which I know will not be a whole number?
Answer: For example, you represent a percentage in the form of thousandths:
a_proc=(a_stake*1000)/a_sum ;
b_stake=(a_proc*b_sum)/1000 ;

Or directly:
b_stake=(a_stake*b_sum)/a_sum ;

You will lose the fractional part of wei, but it is a VERY small value


Is it normal for a kitten to have a big belly?

Question: I bought a food dispenser for my new kitten that allows it to eat as much as it wants. It seems to be getting what seems to me as an abnormally large belly, after just a few days. But I haven't had a kitten before so this might be normal.
Is it normal for a kitten to have a big belly?
I've taken pictures to demonstrate.
Comment: Related question [Can I overfeed my kitten?](http://pets.stackexchange.com/questions/7470/can-i-overfeed-my-kitten)
Comment: @James yep, my question from days ago. The answer was "probably not" but I'm asking this one specifically since I noticed the big belly.
Comment: An answer that was deleted due to it being too short mentioned checking for [FIP](http://www.vet.cornell.edu/fhc/Health_Information/brochure_ftp.cfm). One of the symptoms is abdominal swelling. If someone wants to expand on it or incorporate that into their answer they can.
Comment: My vet told me fat belly can also be caused due to worms , make sure your kitten does not have any worms
Answer: Yes and No. It depends what you mean by "big."
Normally a well fed kitten will have what I refer to as "a fat belly," reflecting their stomach being full of food. One of their main jobs at this stage in life is to store food and grow as fast as possible. The more they can gorge themselves the longer they can survive when mom is away hunting.
A skinny kitten is reason for concern, and should be taken to the vet. To judge skinny and fat you really have to have seen a fair amount kittens.
Kai's advice is perfect IMO: It is good to take your new animals to the vet and you can work out when to immunize them and get them fixed etc. If the kitten is active, playful, eating and eliminating and you have no reason to believe something is wrong with it, it is probably healthy.
If you think the kitten's belly is too big or the kitten has other symptoms take it too the vet.
Answer: I would recommend not using the feeder anymore. Maybe get a timed feeder so the kitten eats 3 meals a day but isn't getting too much food. And definitely talk to your vet about anything abnormal! Cute kitten though!!
Comment: Kittens are growing rapidly and high energy, and need sufficient nutrition and calories to support that. Adult cats shouldn't be free-fed, but kittens should be, at least until around the "teenage" state.


Magento 2.3.4 Google ReCaptcha error even after deleting the ReCaptcha code from my file?

Question: I have implemented Google ReCaptcha in one of my custom contact forms but that did not work as expected. So, I decided to delete all files related to this page ReCaptcha. I even deleted all the files still the captcha validation error "You cannot proceed with such operation, your reCaptcha reputation is too low." is showing. Is there any place do I need to delete anything to avoid this error? Can you help me with this?
Answer: @shanker
Please run below sql query at database side
<code>select * from core_config_data where path like '%capt%';
</code>
You will found a result. Check if still captcha is enabled then disable it from database and check.
Might be will help you.
Comment: Hi @Darshan I wanted to disable only for that one custom form reCAPTCHA and other Recaptchas like login, create user etc.. should work with Recaptcha only. I deleted my custom contact page recaptcha entry from database already.
Comment: @shankarboss if you want to disable for that form only then need to remove captcha code from that custom form. And from that controller file accept post request without validate captcha.
Comment: ok @Darshan. I have two forms with same destination/post URL in the form action. Example Form-A & Form-B. In Form A the reCAPTCHA is working fine because that form has a layout handler and Form B is a custom CMS page, so it doesn't have layout handler. I called the recaptcha in custom cms page phtml by direct calling get->block()->getLayout() statement. Recaptcha is showing but it is showing recaptcha validation error. So I decided to delete the recaptcha from Form B but even I delete all the code related to Recaptcha from form B the validation error message is still showing.
Comment: Is that because of both Form A & Form B having same controller/action path or something else in database I am not sure.


Who is it that is looking for Brahmgyan?

Question: My long quest for the Brahma gyan or moksha has led me to a lot of reading, research and meditation and today a question just popped in my mind that seems to be absolutely essential for me to get answered. The question is:
a) WHo is feeling the intense desire to have BrahmaGyan or atmGyan - is it my physical mind, my subtle body/ subtle mind or my soul?
b) If it is physical or subtle body, then when it dies and the Brahma gyan will be lost?
c) If it is my soul seeking the BrahmaGyan then why does it not already have it?
Comment: Welcome to the stack exchange website! Fortunately your Qn has already been asked earlier on this website.You can search up on the website and read possibly related answers(eg in case of your first Qn you can search like Who/What attains moksha? is it both mind/atman?Or just the atman?).Then you can attach your research to this Qn and modify it to ask even more specific Qns along with your doubts.Happy reading!
Comment: It is simple - suppose you are in a dream-like state. You see many different people, many different worlds, many different situations. Are any one of them real? No. But if you see a ghost in your dream, you'll get scared, why? Because you **don't know** that you are in a dream that is unreal. Liberation is JUST knowing that you and everything around aren't real. Knowledge of liberation is just for physical and subtile body - so that they can coordinate well with real nature of the universe. It doesn't dies. When the physical body dies, knowledge remains (you wake up from your dream!)
Answer: All desires/yearnings, whether they are worldly or spiritual, happen only in the mind of the individual.
In the case of worldly desires, the sense organs first report something of interest and then the mind yearns for it. Lord Krishna explains this in the Gita 2.62

ध्यायतो विषयान्पुंस: सङ्गस्तेषूपजायते ...

The spiritual desire also arises in the mind of the individual. But this desire arises based on experience. The experience that the world and worldly pleasures can never give me everlasting happiness. From Mundaka Upanishad (1.2.12)

परीक्ष्य लोकान्कर्मचितान्ब्राह्मणो निर्वेदमायान्नास्त्यकृतः कृतेन ।
तद्विज्ञानार्थं स गुरुमेवाभिगच्छेत्समित्पाणिः श्रोत्रियं ब्रह्मनिष्ठम् ॥ १२ ॥

Let a brahmana (an aspirant), after he has examined the worlds gained by Karma, acquire freedom from all desires,
reflecting that nothing that is eternal can be gained by Karma. Let him, in order to obtain the knowledge of the eternal,
take sacrificial fuel (Samit) in his hands and approach that preceptor alone who is well-versed in the Veda-s and is
established in Brahman.

Since mind is part of subtle body, for your question a) you can say the all desires occur in the subtle body or sukshma shareera.
Now for your question b)
The 2 benefits of Brahma jnanam (moksha) are

Jeevan mukti
Videha multi

Due to videha mukti, the individual does not have rebirth, so there is no question of losing Brahma jnanam.
(You say you are already doing a lot of reading, so I am not explaining what those terms are as I assume you are familiar with them. If not, drop a note and I'll share more details)
Answer: kshetra is eager to meet Kshtragya;
(the incomplete long to meet the rest to get back in state of POORAN).
The Brahm naad and Brahm Prakash when imbibes in our body (after one crosses a THRESHOLD) then one gets a WHOLE-BODY partner called BRAHM SWAROOP or HARI.
NOTE; AVATAR is the one who is BORN along with HARI and perform BAL-LILA;
HARI RAMA;
HARI KRISHNA;
HARI SAI RAM;
HARI VITTHAL;
HAR HAR MAHADEVA;
HARI MANDIR SAHIB;
The disciple imbibes it later IN LIFE (but before death)
GURU HARI
Deeper insight
Dharama; the one that takes one into KINGDOM OF BRAHM PRAKASH.
HARI Dham;
Kingdom of DIVINE LIGHT or BRAHM PRAKASH or DIVAY PRAKASH.
Maa/Ma/मा-म my BRAHM NAAD as well as BRAHM PRAKASH form.
Comment: As it's currently written, your answer is unclear. Please [edit] to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers [in the help center](/help/how-to-answer).


garbage collection Operation

Question: Can someone please explain me how garbage collection is working?
(I'm using C# and Java).
Comment: -1 For being such a vague question.
Comment: +1 for spawning some good answers relating to garbage collecting, a lot of these links are very informative
Answer: It's too complex topic to be covered in one simple answer.
Here is a list of recommended reading:

Wikipedia: Garbage collection
(computer science)
Garbage Collection: Automatic Memory
Management in the Microsoft .NET
Framework
Garbage Collection: Part 2:
Automatic Memory Management in the
Microsoft .NET Framework
Java theory and practice: A brief
history of garbage collection
Answer: The basic idea behind Garbage Collection is that you don't have to care about memory management. What the Garbage Collectod does is to periodically check upon objects references and find the one that are no more used (not referenced anymore) to reclaim their memory and compact the other.
Garbage Collector use various algorithms to perform their work and they differ for some details from a lenguage to another.
Wikipedia gives you a good starting point.
If you're looking for more in depth information about actual implementation of various Garbage Collectors (Java, .NET, ..) you can check here and here or search google for more.
Answer: Try the book Garbage Collection: Algorithms for Automatic Dynamic Memory Management. It wont have the more recent stuff in it, but it'll get you on your way.
Answer: Perfmon provides a number of counters for GC related performance...
Answer: Here's a nice webcast that discusses simple mark-and-sweep (non-generational) garbage collection, complete with nice animations to help clairy the concept.
Answer: I think you need to know that the Garbage Collector is a thread that runs on your program freeing the memory occupied by the objects whose references make them unreachable. You also need to know that the moment in which int GC runs can't be predicted, you may make a call to System.gc() to make a suggestion for the GC to run but not to make it run, it is the JVM who'll take that decision.
If you have:
Object objectReference = null;
the Object referenced by objectReference is GC bait. The subjects of "islands of isolation" and how the finalize() method works are interesting topics to read. I suggest a quick google search on both.

garbage collection Operation


Cyclotomic polynomials coprime to a fixed polynomial

Question: Let $f \in \mathbb{Z}[x]$ be monic, irreducible and hyperbolic (no roots of absolute value $1$), and such that $f(0)= \pm 1$.
Denoting as $c_{p}(x)$ the cyclotomic polynomial $$c_{p}(x)=1+x+\cdots +x^{p-1},$$
my question is: how can be characterized the (certainly finite?) set of primes $p$ for which $f$ and $c_{p}$ are co-prime, ie there are polynomials $u$ and $v$ in $\mathbb{Z}[x]$ such that $$c_{p} u+f v=1.$$
As an obvious consequence, we have that if $\zeta$ is a primitive $p$-root of unit, $f(\zeta)$ is a unit in $\mathbb{Z}[\zeta]$ and so, for each $1\leq k\leq p-1$, $$f(\zeta^{k})=\zeta^{j} r$$ for some $j$, where $r$ is a real unit of that ring.
Answer: Not an answer, but the set of $p$ that you define is quite likely infinite (Oops, see David's comment). Here is an argument. Let $K$ be the splitting field of the polynomial $f(x^2)$ and $\ell$ a prime that splits completely in $K$. There are lots of those primes and is a reasonable assumption (?) that infinitely many of them satisfy $\ell - 1 =2p$, $p$ prime. Given such an $\ell$ and a root $\alpha$ of $f \mod \ell$, by construction, $\alpha$ is a square, so $\alpha^p = \alpha^{(\ell-1)/2} = 1$ and $\alpha$ is a common root of $f$ and $c_p$ modulo $\ell$ and $p$ is not in your set.
A better argument follows. The resultant of $f$ and $c_p$ grows like $a^{p-1}$ where $a$ is the Mahler measure of $f$, which is $>1$ under the hypotheses. So indeed the set of primes you define is finite.
Comment: Felipe, I'm confused. You argue that a lot of primes are NOT in the set, and then conclude from this that the set is probably infinite. In any case, it is certainly true that there are infinitely many $\ell$ such that $f(x^2)$ splits mod $\ell$ and $\ell \equiv 1 \mod 2p$ -- just apply Cebatarov to the compositum of the $2p$-th cyclotomic field and the splitting field of $f$.
Comment: Thank you very much. The idea of computing the resultant had occurred to me but I was unaware of the link with the Mahler measure. Can you indicate a nice reference for it?
I thought that it should be possible to determine/characterize those primes in terms of the arithmetic of $\mathbb{Z}[x]/(f)$.
Comment: Reference: Lehmer, D. H. Factorization of certain cyclotomic functions. Ann. of Math. (2) 34 (1933), no. 3, 461–479.
Comment: I found an interesting reference to this:

Kaminski, M., "Cyclotomic Polynomials and Units in Cyclotomic Number Fields", J. of Number Theory, 28, 283-287, (1988)

The author proves that if $P(x)$ is a monic, irreducible polynomial with integer coeficients ($P(x) \neq x$) and $P(e^{2 \pi i/n})$ is a unit in the ring $\mathbb{Z}[e^{2 \pi i/n}]$ for infinitely many $n$, then $P$ is cyclotomic itself.


How and when did scientists first determine that hydrogen was the lightest element?

Question: Cavendish first isolated hydrogen and recognized it for what it was; Lavoisier realized that water consisted of hydrogen and oxygen; Dalton used hydrogen as the basis for relative atomic weights by giving it the value of 1 and assuming that the atomic weight of all other elements would be, in relative terms, simple multiples of that value. But why did Dalton assume hydrogen was the lightest element? Who determined that, and when?
Comment: The clue to this investigation is that hydrogen has the lowest density among the elements. Gas density is something which is very much measurable in any reasonable laboratory. It was perhaps natural to choose hydrogen then.
Answer: Cavendish was apparently the first to measure the density of hydrogen, then called inflammable air (air that can burn). It didn't have the identity of an element at the time, of course, and there were other varieties of inflammable air known, but these sorts of questions would be resolved before Dalton's time.
Inflammable air was observed by e.g. Boyle, among others, but it was Cavendish who measured the density and recorded some of its notable properties. This was in Three papers, containing experiments on factitious air (1766), available online. There's a few commentaries on this, e.g. here:

West JB. Henry Cavendish (1731-1810): hydrogen, carbon dioxide, water, and weighing the world. Am J Physiol Lung Cell Mol Physiol. 2014 Jul 1;307(1):L1-6. doi: 10.1152/ajplung.00067.2014. Epub 2014 May 2. PMID: 24793169.

I will quote Cavendish for the main result:

The specific gravity of each of the above-mentioned sorts of inflammable air, except the first, was tried in the following manner. A bladder holding about 100 ounce measures was filled with inflammable air, in the manner represented in Fig. 3. and the air pressed out again as perfectly as possible. By this means the small quantity of air remaining in the bladder was almost intirely of the inflammable kind. 80 ounce measures of the inflammable air, produced from zinc by the vitriolic acid, were then forced into the bladder in the same manner: after which, the pewter pipe was taken out of the wooden cap of the bladder, the orifice of the cap stopt up with a bit of lute, and the bladder weighed. A hole was then made in the lute, the air pressed out as perfectly as possible, and the bladder weighed again. It was found to have increased in weight $40 \frac{3}{4}$ grains. Therefore the air pressed out of the bladder weighs $40 \frac{3}{4}$ grains less than an equal quantity of common air: but the quantity of air pressed our of the bladder must be nearly the same as that which was forced into it, i.e. 80 ounce measures: consequently 80 ounce measures of this sort of inflammable air weight $40 \frac{3}{4}$ grains less than an equal bulk of common air. ...
... Taking a medium therefore of the different trials, 80 ounce measures of inflammable air weigh 41 grains less than an equal bulk of common air. Therefore, if the density of common air, at the time when this experiment was tried, was 800 times less than that of water, which, I imagine, must be near the truth, inflammable air must be 5490 times lighter than water, or near 7 times lighter than common air. But if the density of common air was 850 times less than that of water, then would inflammable air be 9200 times lighter than water, or $10 \frac{8}{10}$  lighter than common air.

(Emphasis mine.)
The value of 1/800 the density of water is commonly accepted even today, thus Cavendish is saying that the density of hydrogen (and, by Avogadro's law (1812), the atomic weight of hydrogen) is 1/7th that of air at standard temperature and pressure. The true ratio should be about 1/13th that of air (0.09 g/L to 1.2 g/L), about half of what Cavendish found.
I suppose no other gas would (or could) be found to have such a low density (and by extension, atomic weight; but this would come 6 years after Dalton's paper).
Comment: Thank you; that is very thorough and fascinating. It helps explain the basis on which Dalton constructed his system, using one as the value for the "atomic weight" of hydrogen. Thanks again! Gilbert Reid. gilbertreid.com


How does Game and Watch's hammer work?

Question: I remember reading that in the older games, you could not get the same number as either of the last two uses, but while I was playing on him on Super Smash Bros 4, (over multiple games) I got many repetitions of the same number, such as two 9's in a row and even three 4's in a row. Did they change the mechanic?
Answer: SSB4 removed the mechanic altogether, letting each independent use of the hammer roll between 1-9 randomly, so each number always has an ~11% chance of appearing.
More info on the move in the wiki here.
And all changes to Game and Watch listed here.
Comment: Hmmm, so it seems like he is more luck based than ever now.
Comment: That would definitely seem to be the case. No more having to swing "dummy hammers". To be honest, I've stopped using the hammer altogether now, except as a joke. Rolling a 1 is just too costly.
Comment: Yeah, but rolling the 8 or 9 can win the whole game. I will probably use it less now, but i'll still use it.

How does Game and Watch's hammer work?


Force required to lift an object

Question: The force required to lift an object with weight mg must be slightly greater than mg to produce a net force upwards. There's one thing I'm struggling to understand with this concept though and would appreciate if someone can clarify it for me. If an object is resting on a table then it will have a reaction force (the normal force) also acting upwards on the object. Since the net force on this object is zero as the normal/weight forces cancel out, then shouldn't any force applied upwards to the object cause it to start moving, regardless of whether the force's magnitude is less than mg or not?
Answer: The normal force only acts on that object while that object is in contact with the surface it is resting on. It is also proportional to the force being applied onto the surface - which is not necessarily $mg$ but would be if there were no other forces involved. Say you went to lift the object off that surface, and you applied a force $F<mg$ upwards. What you would get is a gravitational force going down of $mg$ and a normal force of $N=mg-F$ going up and your force of $F$ going up. In the end, the situation is still balanced and the object doesn't move. The normal force does not always provide a $mg$ force going up. It's only enough to keep the object from moving down through the surface.
Answer: In a sense, you are correct.
Consider the mass resting not on a table, but on a very easily stretched trampoline.
The mass is at rest;  the force of gravity is exactly balanced by the force exerted by the elastic stretching of the trampoline.
If you apply the slightest upward force, the mass will begin to accelerate upward.  However, this allows the elastic trampoline to contract, so it exerts less upward force.  The net upward force thus decreases, bringing the upward acceleration down to (and past) zero.  The object eventually stops at a new level, with gravity balanced by the reduced upward force and the new upward force from you.
Now consider the table to be a really stiff trampoline...

Force required to lift an object


Create contact sheet in PaintShop Pro X7?

Question: Is it possible to create a contact sheet based on multiple images in PaintShop Pro X7? Is it possible to do this while retaining the sources' alpha channels?
Answer: I created a folder containing 9 images.
I named them sequentially 1.jpg through 9.jpg
I wanted image 5.jpg to be the center of what I was doing.
I created a script to create a large file to place these into.
I then copied each of the 9 source files into the new files making a grid 3 x 3.
I then saved this script.
As long as I have all names the same, I guess it works.
Note: This was first part of an exercise to create a Christmas ball where I took the output from this, merged all layers, use effects / geometric / circle and effects / geometric / spherize.
I hope this helps.
Comment: Can you show that script?


Electret Condense Microphone, the function purpose of parallel capacitor

Question: I got a schematic diagram of Electret Condense Microphone(ECM), shown as in the below. I would like to know the function purpose of C1 and C2. Each of value is 33PF and 10PF. Thanks.
Comment: My first guess would be the capacitors provide some frequency-selective compensation for the frequency responses of the microphone's mechanics (e.g., the electret diaphragm) or its JFET or both. My second guess is the caps provide additional noise suppression for short-duration impulse voltages on the power supply Vs or ground rails (e.g., switched-mode power supply noise).
Answer: Electret maker PUI says: "Each
microphone features GSM buzz-blocking capacitors," but they work to eliminate other interference as well.
Comment: That jives with my guess.  33pf would only help at radio frequencies, so they keep out RF when it's used on a phone.  No effect at audio frequencies.


RDC stops working after a period of time

Question: I have a workstation with RDC configured for the employee. When they leave at the end of their day they lock the pc (windows key + l). They go home connect to our VPN and log back in. Everything works fine. The following morning they will attempt to log in before they return to the office. The computer does not respond to the RDC request. I've found that it becomes completely inactive to any ICMP requests. Once the user reboots the computer everything works fine again. I'm going to turn off RDC, reboot, turn RDC back on and reboot again to see if it fixes the problem. Until then does anyone have any other ideas?
Comment: What do they do from home at night? Does it work if they just connect, disconnect, and reconnect from home (without doing anything else)?
Comment: it works fine if they connect once then disconnect then within a short period reconnect. It seems like a long period of time causes the computer to lock everything out.
Answer: I figured it out. Turns out the Ethernet diag utility was the problem. Uninstalled it and things have worked fine for 2 days now.


human synonym for the word 'medicine'

Question: What is the human synonym for the word 'medicine'? Basically,  I want to know  what do we call a human who can act like a medicine for curing our emotional wounds?
Comment: A *priest* / *rabbi* / *imam* / *psychologist* / *psychiatrist* / *friend* / *parent* / *sibling*?
Comment: 'Antidote' is broad enough to include humans. For example: "The serene Anny was the perfect antidote for Paul's nervous restlessness."
Answer: In this context healer might work:

A person or thing that mends or repairs something

The 'something' can cover a range of things including physical, mental and emotional.
Answer: Probably psychotherapy is close to what you are looking for:

treatment of mental or emotional illness by talking about problems rather than by using medicine or drugs.

Psychotherapist is the person who gives psychotherapy
(M-W)
Comment: Upvote for great minds thinking alike, but I'd suggest *psychotherapist*, as OP is looking for a person, rather than a methodology.
Answer: I believe the word you are looking for is Consoler, which Noah Webster defines as "One that gives comfort." in The American Dictionary of the English Language (A.D.E.L.), or more specifically, a consoler is a person who consoles other people. A.D.E.L. defines console as:

verb transitive [Latin The primary sense is either to set or allay, to give rest or quiet, or the sense is to strengthen, in which case it coincides with the root of solid. The latter is most probable.]
To comfort; to cheer the mind in distress or depression; to alleviate grief, and give refreshment to the mind or spirits; to give contentment or moderate happiness by relieving from distress.

 I doubt any further explanation is necessary, although it may be worth note that the words like alleviate is a word often used in medical contexts.

"1. To make light; but always in a figurative sense, as it is not applied to material objects. To remove in part; to lessen, mitigate, or make easier to be endured; applied to evils; as, to alleviate sorrow, pain, care, punishment, a burden, &c.; opposed to aggravate." — A.D.E.L.

 Hence alleviation in the context of consolation refers to relieving ourselves of mental pain, anguish, sorrow and so on.
Answer: The original "Star Trek" TV series had an episode with such a character, who was known as the Empath. This is not a recognized word, although the back-formation from empathy is obvious.
Comment: Empath didn't mean this in the context of Star Trek: The Next Generation, but instead referred to a person who had the psychic power to sense another person's emotions, which is (almost) what empathy is. However, despite being helpful, merely knowing another person's emotional state doesn't necessarily do anything to improve it. Dianna Troi had that ability but her job title on the ship is more relevant. A cursory glance reveals to me that they seem to have used the wrong word in her title instead of the proper one though, which is a shame, since it would've made a very good example otherwise.
Comment: I don't remember that.  I was thinking of Deanna Troi in TNG.  Put in a reference and link, and I'll upvote if you notify me.

human synonym for the word 'medicine'


Change sfdc Approval process email reply for wrong spelling APPROVED

Question: When we use approval process, we can approve through email. This is my question, because we can reply wrong spelled word in email, how can I modify the salesforce reply if the APPROVED word is misspelled. Thanks
Comment: Change your email template to emphasize the correct responses. Use styling to make it super apparent.  I simply used YES, NO to make it super clear to the responder. Note there is also Chatter approval if your users use chatter and the UI is much more obvious to the  approver
Answer: From this Doc Enable Email Approval Response

Note: For salesforce.com to process your response the word
  APPROVE, APPROVED, YES, REJECT, REJECTED, or NO must be in
  the very first line of the reply email. Also, any comment
  must be in the second line.

I can say that you have to pass the information(How to approve) in Email so that one can reply correctly.
Although it is possible to reply in other languages.

Email approval response works in all languages that Salesforce supports. The response word or phrase is checked using the current user language dictionary. If no matches are found, the response word or phrase is checked in all other language dictionaries.

But i don't think misspelled words will work.


What is the difference between $|0\rangle $ and $0$?

Question: What is the difference between $|0\rangle $ and $0$ in the context of $$a_-  |0\rangle =0~?$$
Answer: $|0\rangle$ is just a quantum state that happens to be labeled by the number 0. It's conventional to use that label to denote the ground state (or vacuum state), the one with the lowest energy. But the label you put on a quantum state is actually kind of arbitrary. You could choose a different convention in which you label the ground state with, say, 5, and although it would confuse a lot of people, you could still do physics perfectly well with it. The point is, $|0\rangle$ is just a particular quantum state. The fact that it's labeled with a 0 doesn't have to mean that anything about it is actually zero.
In contrast, $0$ (not written as a ket) is actually zero. You could perhaps think of it as the quantum state of an object that doesn't exist (although I suspect that analogy will come back to bite me... just don't take it too literally). If you calculate any matrix element of some operator $A$ in the "state" $0$, you will get 0 as a result because you're basically multiplying by zero:
$$\langle\psi| A (a_-|0\rangle) = 0$$
for any state $\langle\psi|$. In contrast, you can do this for the ground state without necessarily getting zero:
$$\langle\psi| A |0\rangle = \text{can be anything}$$
Comment: Maybe it is not very important, but it should be pointed out that the "_actual zero_" is still a vector from the Hilbert space and not the scalar zero from the field over which the Hilbert space is defined. So, the R.H.S. zero in $a_{-}|{0}\rangle=0$ is not the complex number $0$. Rather, it is precisely the null vector of the vector space that the Hilbert space is.
Comment: I think you made it clear that it is a vector and not a number when you mentioned calculating matrix elements of an operator in the ""state" $0$", but I just thought it might be explicitly pointed out.
Answer: $|0\rangle$ is a particular nonzero vector in the Hilbert space associated with this system. That vector is nonzero -- in fact, it's usually normalized to have magnitude 1. The 0 on the right refers to the zero vector in the Hilbert space. So they're quite different. For one thing, $|0\rangle$ is a possible state for a particle to be in. 0 isn't (since only unit-magnitude vectors are possible states).
Comment: I think you're misunderstanding what a change of basis is. Shifting the origin of a vector space is not the same thing as a change of basis. A change of basis is an invertible linear transformation (i.e., multiplication by a nonsingular matrix for finite-dimensional spaces). One consequence of this: In any vector space, any nonzero vector is nonzero in all bases.
Comment: @Tedd Bunn one question: can't we have a state $|0\rangle$ where the ket represents a column vector in a particular basis where all components are zero? for an analogy in 3-space.. take a point with finite coordinates and shift the origin to that point, and in this new basis the point is represented as a 0-component vector.
Answer: You may consider 0 as an eigenvalue and write $a|0\rangle = 0|0\rangle$.
Any eigenvector $a|\alpha \rangle = \alpha |\alpha \rangle$ is of different "length" than the corresponding normalized vector $|\alpha \rangle$. In your particular case the vector $0|0\rangle$ is of zeroth length.
Answer: $0$ is the additive identity of the vector space, i.e. the element of the vector space which satisfies $$0 + v = v$$ for all $v$ in the vector space. No system can ever be in this state since it is patently unnormalizable.
$|0\rangle$ is the name of an energy eigenstate of some Hamiltonian operator $H$ with the lowest eigenvalue in its spectrum. For example, for the harmonic oscillator $|0\rangle$ corresponds to the gaussian function $~e^{-x^2} $ while "$0$" actually corresponds to the real number zero. For a two-state system "$0$" would correspond to the column vector $\begin{bmatrix}0\\0\\ \end{bmatrix}$.
Comment: As the other answers point out $0$ is not the real number zero when appearing as the result of applying an operator to a state, rather it is also a vector. In position representation it is an $L^2$ function, $0 \colon \mathbb{R}^3 \to \mathbb{C}$, $0(\vec r) = 0 \in \mathbb{C}$.


Customer Portal Access to specific Library Files

Question: I have a need to allow customer community users access to specific files based on a field on their contact records.  Is this possible?  I am thinking that I could have a Library that I would add the files to that they need access.  I am not seeing how to add only some of the customer community users to a public group to give them access to the library.  Thoughts?  I have the basic Customer Community portal licenses.  If this could be done with the Customer Community Plus licenses, I would buy them.  Thanks!
Answer: With Customer Community Plus licenses you could do Apex Managed Sharing which would make what you want to do possible. I do not know a way of doing what you're asking about using criteria-based sharing rules with a basic Customer Community license.


Visa Information (Schengen Application, Enlargement Members)

Question: Every country asks in its visa form whether you stayed previously in this or some other Schengen country. Some people stayed in countries which are now in Schengen, but have not been part of Schengen or Schengen has not even existed when you have been there. Should I mention these countries or leave the field blank?
Comment: For your question:  "Schengen" is the state existing on your application date.  If you previously travelled to a country that was part of an enlargement, you would write it down as Schengen.  They are not concerned with the enlargement history, and they expect applicants to define "Schengen" as it currently exists (i.e., your application date).
Answer: Those visa forms generally don't expect an exhaustive list of your past travels. This means that if you've traveled to today's Schengen countries let's say 50 times in your life, listing them one by one won't really make sense. Yet in case you've entered Schengen twice and another couple of times to current Schengen countries before they joined the union, it would make sense to list all of them. On top of that, you need to mention the year when the journey took place anyway, so they will see that you've been to those countries with a separate visa and not a Schengen visa.
Long story short, be open and honest, and use common sense.
Answer: If you know the dates you where there you should probably put them on the application.
Problem is that Schengen was established in 1995 (20 years) ago so since that time you have already changed your passport more then likely a couple of times so even if you mention it you should be prepared to prove that these actually took place especially if these were done prior to SIS, which I think would be prior to 1990.
Long story short what the immigration authorities are trying to establish is that you will go away once the term of your visa or maximum duration of stay has been reached.  So if you have 5-6 entries and exits during the Schengen era they may be sufficient but if you feel like adding a list of all of your entries and exits put them on a separate sheet and attach to the application if possible.


Expandable textbox as the main component on the screen

Question: I have a screen that its main component is a text box.
Users add the text by pasting it in the text box and then click on the button, which results with an image generated in the screen.
it is the main component because the user enters text many times, each time to generate a different image.
My question is: most of the time the text is not so long, but there are times the text is long and the user needs to see the text they entered.
I thought of an expandable text box that the user can pull down to see all text when needed? and what do I do with the button? Leave it in its place?
Answer: There's a script for an auto-expand textbox where the user doesn't have to touch any element on the screen, beyond the submit button that can remain static.


Grounding Rod in basement?

Question: I purchased an older house and when running some electronics i got a hum. Did some research and trial and error to figure out why What I came to realize its a ground problem in the old house. I have a new electrical panel so I'm up to code but the ground looks like its nothing more than a the copper line hooked up to the water pipes in the basement.
My question 1...Could I knock a small  hole in my basement floor and put in a grounding rod and switch the copper ground to use it?
Question 2 ...would I need to cut the power to the house to safely do that?
Thanks!!
Comment: Don't knock a hole. Borrow or rent a rotary hammer and drill just a 1/2" hole. I put mine under the basement stairs by removing the bottom tread.
Answer: If you get hum in audio electronics, it's almost certainly not the result of a poor electrical system ground. In fact, if your electrical system grounding conductors were all well-bonded but not grounded at all, your stereo would still be perfectly happy.
There are several much more likely potential sources for hum, mostly due to defective power supply filtering capacitors or power supply decoupling capacitors, "ground loops", capacitive, inductive, or common impedance coupling. Unfortunately, isolating the cause and curing it can be an adventure in debugging and diagnosis.
Older audio gear may have electrolytic or tantalum capacitors that have aged and dried out, or they may simply have failed, which reduces their capacitance and increases 60 Hz or 120Hz ripple in an audio component's power supply, causing increased hum. If your power amplifier or receiver creates hum in your speakers all by itself with no inputs attached or the input selector on an unused input, this can be the cause.
Ground loops are created when there is more than one ground path from device A to device B. The multiple paths form a loop, topologically speaking, hence the name. A ground loop is like a 1-turn transformer, and can couple stray magnetic fields from power conductors (or power transformers) at the 60Hz AC power frequency, which then results in a 60Hz current and voltage induced around the ground loop, which can impress itself on the "ground" of the unbalanced signal inputs in one of the devices, which you hear as hum. Ground loops can be difficult to deal with. Unplugging audio cables until the hum ceases, then replugging them one by one can point to a culprit ground loop.
Inductive (or magnetic field) coupling can occur between the magnetic fields of large power transformers (usually found in high power amplifiers) and sensitive magnetic devices like phonograph cartridges, magnetic tape heads, etc. This is why expensive audio gear will often have toroidal power transformers, which result in less stray magnetic fields and less likelihood of magnetic coupling.
Capacitive (or electric field) coupling can occur between high voltage waveforms (like 120V power line) and high impedance signal nodes (like the inputs of preamplifiers and even power amplifiers).
Capacitive and magnetic coupling is the reason quality electronics is packaged in metallic packages: a metallic conductive enclosure will act to prevent electric and magnetic fields from entering the enclosure (the Faraday effect)  causing undesired coupling to sensitive signals. You can easily diagnose electric and magnetic coupling by physically separating audio components. The hum will decrease with increased separation.
Common impedance coupling occurs when an interfering signal (like AC power currents) flow in an impedance shared with another signal circuit, perhaps because of a small-gauge or poorly manufactured powerbar power cord shared by a large power amplifier and a preamplifier. Connecting large power amplifiers on their own circuit, or with their own large-gauge power cord into a different receptacle on the same circuit can benefit an audio installation suffering from common impedance coupling. Making sure the receptacle powering your audio equipment is the first on a circuit run from the electrical panel, and that the run is as short as possible, and no other appliances are on this circuit can also help.
Finally, making sure that the audio cables connecting your audio components are high quality, with good ground shield coverage, can minimize inductive and capacitive coupling to the signal conductors. Make sure that the connectors make good "ground" contact and are not oxidized or corroded (that's why the better ones are gold plated), so that the cable shields can be effective.
Whew. That's a long answer, and my fingers are cramping up. Hope it helps.
Answer: Hums in audio electronics are generally not "ground problems" of the sort that'd be fixed by driving a ground rod.  Instead, they're the result of such gremlins as miswired equipment that injects noise pickup onto signal references and poor filtering/rejection of the powerline.  Using a filtering surge suppressor for your audio equipment can help send the noise back the way it came -- beyond that, it's a matter of hunting down sources of electrical noise and suppressing them, and making sure that noisy shields and such aren't bridged to signal references inside your cables or equipment (research the "pin 1 problem" if you want to know more about this).
As to putting a hole in your basement floor for a ground rod -- there's a good chance you'll have yourself a tiny spring in your basement if you do so.  Better to go up and out instead -- and retain the existing water-pipe ground electrode, too, as your water system still needs to be bonded to the grounding system!
Comment: If there's hydrostatic pressure under the floor now it's almost certainly finding an exit. I doubt a new hole would change anything.
Answer: Do not punch a hole in your basement floor or you'll find out all about ground-water.   If you want to add a ground rod, go "up" to exit the building at a convenient point, for instance the electrical service entrance.
There is no rule against having more than one ground rod.  However the ground rods must be connected together by ground wires - you can't use ground rods as a substitute for ground wires (because earth doesn't actually conduct electricity all that well.)
Even if you think it's hokey, there is nothing wrong with using a water supply pipe for a ground "rod".  Actually, Code is more favorable to water pipes than actual ground rods.  If you want to use ground rods only, you either need to do an expensive test to confirm low resistance, or use two ground rods.
If you're going to remove a ground temporarily, then yes - you'll want to shut off main power.  But even then, your "ground" is bonded to neutral in your main panel, and neutral goes to the transformer, so it could have some fairly significant "float" relative to ground, enough to kick your butt hard.  I would rig a temporary ground around the work area, e.g. if you wanted to disassemble that water-pipe bond to clean it.  Green Scotchbright pads are pretty good for cleaning up copper.
Answer: Many homes have 2 grounds depending on where you are. I would not eliminate the existing ground but add a 2nd if you feel this is the right thing to do it can only help but not all noise issues are from weak grounds many are from electronics that create harmonics on the neutral. Most modern PC Power supply's, fluorescent ballast and dimmer circuits cause the "hum" you describe. Better grounds can help but may not eliminate the issue without RFI FILTERS that help dump the noise/ harmonics to ground.

Grounding Rod in basement?


How strong are vampires in The Vampire Diaries?

Question: What is the strength level of vampires in The Vampire Diaries universe? What feats of strengths have been shown?
Comment: i think we see someone punch through a wall, but i dont think you ever see anyone pick up a car even.
Answer: The strength level of the vampires in the show is not always consistent, and also seems to vary depending on several factors (how old they are, how well-fed they are, etc.) But typically, they seem to have strength that's supernatural but not ridiculously so; perhaps 2-3 times what a good bodybuilder could manage.
To give you an idea how varying it is: in some cases, we have seen vampires break out of handcuffs or bust up large furniture. In other scenes, though, they've been successfully restrained using plain ropes. If anything, I think the werewolves are the brutes of the series: Tyler Lockwood needed to be locked up in a very heavy solid-metal room when he changed.
In combat, they are shown to be above average hand-to-hand fighters. They routinely snap people's necks with ease, and punch their fists through people's chests to rip out hearts/spines/etc. They can also manhandle average-sized human adults, including throwing them across the room.
They have never been shown to have ridiculous levels of strength: to my knowledge, they've never ripped a steel door off its hinges or stopped a moving car or lifted incredibly heavy objects.
Mostly, they rely on their speed and stamina to get them out of trouble.
Comment: their speed like, doesn't match their strength its kinda weird.
Comment: Muscle and muscle fiber used for speed and strength are different. A kick boxer and a marathon runner and sprinter all have different leg strengths
Answer: TVD vampires don't really have strong "lifting" feats of strength or at least anything really definitive. What has been shown is that even newly made vampires like Caroline Forbes can easily lift an adult human off the ground with one hand and showing no strain whatsoever. She also kicked an adult male weighing 180lbs 10ft through the air and he would have gone further if he didn't hit a tree. Shortly after she was turned into a vampire Caroline Forbes was able to move a stone slab that was around 6ft tall x 3ft wide x 4-6in thick without straining herself.
In Season 1, Elena flipped her car and Damon mentioned moving the car to the side of the road, which suggests that pushing/dragging around 1-2 tons is doable.
Damon and Stefan have also shown being able to break solid chains without much effort.
One of the greater feat of strengths that I've seen is when Stefan jumped more than 50 feet vertically while carrying Elena. He did so with ease and didn't even bend his legs much.
There is another feat, though it is more of a durability feat than a strength one. I only include it because durability and strength are closely related. The body has to be tough enough to withstand the forces exerted by the person lifting or hitting something. Otherwise what would be the point if a vampire lifted a person or car and broke their arms doing so? Their bodies have to have a certain amount of toughness. When Elena was first turned into a vampire she jumped off of a 100 foot cliff. She landed crouched down, so her body absorbed a lot of the energy but she wasn't injured at all. No broken bones, torn muscles/ligaments or even a bruise. And she was a newly made vampire. Considering vampires get stronger as they get older, they will also get tougher.
Comment: The toughness bit doesn't make any sense when taking into consideration how easily vampires are damaged. They also do not have superspeed from muscle. If they did there would be supersonic shockwaves, G forces rendering normal people they carry into a red mist, holes in the pavement, etc. Their speed resembles mass effect speed. Warping spacetime. If their strength is tactile telekinesis then they are only tough when actively using their strength. It does go hand in hand with their telepathic abilities.
Answer: I think they can't be more stronger than the witches. Because, As shown, the originals also came into existence by the witch.
Comment: Hi, welcome to SF&F.  Without qualifying how strong a witch is, this doesn't answer the question, even if you can justify that the vampires are not as strong as witches, which you haven't supported.
Answer: Strength/Striking Force: Vampires here have been shown to hit so hard that they decapitate targets with their bare hands. See Damon beheading Kia. The strength they exude is so powerful that anything in their hand becomes a weapon. In Season 7 Ep.12, Damon Salvatore was shown throwing an envelope so hard that it beheaded a vampire and then embedded itself halfway into metal.
Durability: A day-old cancer vampire turned by Caroline Forbes was shown stabbing himself 8 times in the heart in an attempt to end his cancer pain, but all to no avail.
Healing and Regeneration: Damon and Enzo as Augustin Vampire Subjects were weakened below human levels with vervaine and given no food or water, yet had their organs like liver, kidneys, eyes etc. harvested for over 50 years.


I accidentally lost the key to my wallet

Question: So I recently formatted my drives again and wiped my hard drives. I mistakenly did not copy my Account key but I copied my password. Is there anyway to gain back my account?
Comment: There are various data recovery tools or services you can use. Otherwise you may be able to recover it if it was generated from a HD wallet using the original seed. Please search on previous questions.
Comment: @o0ragman0o is right. If at all it is HD wallet, if not possibilities to recover is zero.
Comment: suggestion: change your post title to a question: "Is there any way to recover the key to myetherwallet?"
Answer: MyEtherWallet is not a "web wallet". You do not create an account or give MEW your ETH or tokens to hold onto. MEW is simply an interface that allows you to interact with the Ethereum blockchain.
For security & privacy reasons, no sensitive data is saved, stored, or transmitted when you use MyEtherWallet. They, like anybody else, only have access to the information that is publicly available on the blockchain.
Unfortunately, that means they cannot:

Recover your private key
Access you account
Recover or reset your password
Reverse or cancel transactions
Recover your account
Send your ETH or Tokens from one address to another

There may be a chance that you saved it without realizing it. So, just in case:

Do a full search of your computer for "UTC-" and see if the private key shows up.
Do a full search of your computer for your address without the 0x at the beginning.
If you know when you created it, look through all files during that time period for any documents that may hold your key or screenshots.
Generate a new wallet via https://www.myetherwallet.com/#generate-wallet and take a look and the different options you may have downloaded or saved. Sometimes that can jog your memory.

In the future, it may be prudent to print out a paper version of your wallet and keep it in multiple physical locations.
I'm really sorry.
Answer: Did you check in with your wallet provider? Myetherwallet has a help center, and they address your question (under "I no longer have my private key. What can I do?").  Basically the short of it is unfortunately: nothing (they explain why). https://myetherwallet.groovehq.com/help_center
This said, while searching the internet for lost key etherwallet, I found a thread started by someone in a similar situation to yours. Someone else answered: "If you didn't write anything to the disk after your formatted it the data it may still be recoverable." Not sure if that applies in your case, but may be worth a deeper look? https://www.reddit.com/r/ethereum/comments/4o5bje/help_recovering_ether/


Should I care about Low Testosterone?

Question: My doctor wants to start some testosterone treatments on me because he says my levels are too low (they are 231 ng/dL and he said it should be between 348 to 1197). The question I have is, given that I don't have a girlfriend/wife, have never been on a date and am still a virgin (age 38 virgins, yes we exist), is there really any need for me to worry about my testosterone level?  It seems everywhere I look on google it is all about sex and sex drive. As someone that has no need for sex or a sex drive (see no wife nor girlfriend), is there anything else I would even care about? Do I really need to up my testosterone?
Comment: Testosterone is vital to normal functioning, and you are too young to be going through andropause. Cardiovascular problems are at the top of the list with longstanding testo deficiency.
Comment: Before accepting any treatment with artificial testosterone, I would try by all means to rise my natural levels for a while (basically getting more sleep, doing strength training, and eating some more saturated fats). Try everything at your disposal before starting a testosterone treatment, since they are for life. Once you start receiving exogenous testosterone, your balls will become lazy very quickly an then they will produce even less than before, making you dependent from the exogenous source. Also, go and see another doctor, look for a second opinion.
Comment: @DarkoSarovic Thanks for the info, I wish you put this as an answer as I would accept it as an answer.
Comment: Since your doctor recommends it you should probably listen. I don't always agree with everything they say, but they are rarely wrong.
Comment: This is a very personal question, and medical advise as well. Both of these are off topic for the site, unfortunately.
Comment: i strongly recommend you listen to this entire podcast, especially the part about the man who had NONE.http://www.thisamericanlife.org/radio-archives/episode/220/testosterone
Answer: Firstly, only your doctor can know if your levels are actually low enough to cause these symptoms, so you should ask them. I'm only including the rest of this answer to let you know it's worth asking.
As it relates to fitness, low levels of testosterone can lead to reduced muscle and bone mass [1]. Low muscle mass (and presumably reduced muscular gain) is obviously bad if you're interested in getting stronger or bigger. Reduced bone mass is bad for just about any kind of exercising that involves impacts or heavy loads, like running or lifting, because it increases your chance of injury.

Should I care about Low Testosterone?


How to set specific startup routines?

Question: Another simple question for those keeping track, but I was wondering how and where I could setup the startup routines for my mac. What I would really like is for email to open, messages and activity monitor to open but not in a new window, and for safari to open in fullscreen mode in a separate pane. Is this possible or at least where might I look? I'm less interested in accomplishing this as learning some of the more behind the scenes stuff related to the operating system.
Comment: Depends on how complex you want it go, simple things such as opening App can done as @bmike mentioned from Start Up Items. If you want more complex things like opening Safari in full screen, or running some script can be accomplished with Launch Agents.
Answer: Open system references and go to the accounts or users section.
Add the applications needing to start to each user's startup items. You can start apps (and optionally hide them) and mount shares as well as start automation scripts.

How to set specific startup routines?


FaceTime camera has blurred lines during a FaceTime call but not during skype

Question: When I make a video call through FaceTime on my iPad the person I talk to has blurred lines through the video. I've tested it myself by calling from my iPhone and I see these blurred lines as well. However when I make a Skype call the video is crystal clear?  It's an iPad 4 if that makes any difference. Please help me
Comment: What version of iOS is it running?
Comment: Sorry iOS version 9.1
Answer: Try a restart, hold the power button and home button together until you see the Apple logo appear, then release. It's perfectly safe and you won't lose any data, I restart my iDevices all the time.
It that doesn't work, report the bug to Apple and hope the public release of iOS 9.2 fixes your camera. You could update to the beta of iOS 9.2 if you're desperate for the camera to work, but the beta would also cause new, bigger problems.
Comment: I've tried the soft boot and I've also factory restored my iPad but neither fixes the issue. Thanks you and I will report to apple and see if there are any solutions.
Comment: I've just updated it to iOS beta 9.2 and it seems to have fixed the issue  thank you.
Comment: @MonicaMM Glad to hear it.
Answer: There could be countless issues, but I'd like to mention two.
Facetime's problems may be caused due to the fact that it uses the client-server model, which is a considerably slower communication method than operating on peer-to-peer. This peer-to-peer protocol used by Skype is what makes connections more responsive, and that effectively means less bugs during video calls.
Another possibility is a bug in the app itself. The countless times I have had to do a hard reset is beyond exhaustive, but you could try and see if it helps in any way.
A hard reset is done by pressing and holding down the power and home buttons until the Apple logo appears. I wouldn't be surprised if it still doesn't work though, the app is the most faulty one I have yet used.
Comment: Thank you for your help. I took a risk and updated to iOS 9.2 beta and it seems to have solved the issue perfectly.


Best way to sync vimrc files

Question: What is the best way to sync my vimrc to multiple computers, I have multiple different linux and windows installations that I would like it to be synced to and would prefer to rely on some sort of cloud based system. Currently I am using dropbox, but it seems like dropbox will only sync stuff actually in the dropbox folder. I would prefer for this to happen in the background, but if I have to run a script that won't be a problem.
Answer: I keep all of my dot files (including my .vimrc and my other .vim stuff) in a git repository. I then have a script which creates symlinks in my home directory to all of the config files in my git repository. As long as it isn't too many files, I imagine you could manually generate those symlinks if you had to. The nice thing about this setup is that when I pull into the config repository, all of my config files in my home directory are updated, since they are just symlinks. You could do a similar thing with dropbox by having symlinks into your dropbox folder. I would recommend writing a script which can crawl a dotfiles subfolder in your dropbox folder and generate the needed links. Since you are on both Windows and Linux, you may need two scripts, one which uses mklink and the other which uses ln -s respectively. For more information on how this can be done, checkout this lifehacker article. Once you have these links (or have your script generate the links), when dropbox automatically updates your files, the changes will be automatically happen to all your machines. The only catch is that if you add a new file (rather than update an existing one), you'll need to remember to re-run your symlink script.
Comment: If you use git instead of dropbox, the last point about needing to rerun the link script upon getting a new file can be mitigated with a post-merge git hook script which adds missing links.
Answer: If you always have 1 source, you could write a quick script to copy it to your clients, then put that into a cron job.
Comment: I guess I could keep one source in the dropbox folder and have scripts to sync it right next to it, I was hoping to have some solution that would work more like dropbox, but sync to ~/.vimrc and $HOME/_vimrc
Comment: @PeterMichealLacey-Bordeaux There might be.  Are you looking to have the vimrc files able to be changed on all machines, or are you looking to mirror based on a source machine?
Comment: I would like to be able to change them on all machines

Best way to sync vimrc files


Are we going to have to pay back the government for the stimulus checks?

Question: I've heard stories about the stimulus checks that the government is giving to the US people. I've heard that sometime in the future, the US citizens are going to have to pay the government back for the stimulus checks. I've also heard that we won't have to pay them back. I'm wondering which of these stories is the truth. Are we going to have to pay the government back for the stimulus checks or not?
Comment: If you're asking about the stimulus checks specifically, the answer is no. They're grants, not loans. If you heard a specific claim that they were loans and people would have to pay them back, you should ask about that on [skeptics.se]. More likely, those people were talking more generally, in that these stimulus payments increased the deficit and at some point the US government (and by extension US citizens) will have to pay that money back.
Comment: @divibisan in the end the stimulus checks are paid for through tax money and thus will be repaid by tax payers. In reality of course they'll probably just end up increasing the national debt and inflation levels, but taxes are the usual way that governments pay for their expenses.
Answer: It depends on what one means by "we" and "pay the government back for the stimulus checks".
The stimulus are not loans, so recipients don't have to pay the government back directly, like one would with, say, a student loan.
However, the stimulus checks have been so far paid for by increased government debt, which means that taxes that we pay will go towards servicing that debt and its interest. Increased government debt will eventually result in either increased taxes, decreased spending/services or inflation via money supply increase (which means one's money buys less).
So the true answer is jedi hand wave "it depends on your point of view".
Comment: @JonathanReez: I'll have to check, but I was the impression it was debt, hence the proposal for increased business taxes and taxes on those making over 400k. Note that "literally printing more money" (and its not literally, because most money is credit now, via banks and FED) is one of the ways to service debt, but leads to inflation (if all else is equal).
Comment: @Joe: This begs the question of "what is money"? Because Congress does technically control the supply of money (the US Mint answer to them); however, as I mention the FED (and arguably individual banks as well, due to fractional reserve banking) control the amount of credit that is available, which we currently treat as money.
Comment: Wasn't the CARES Act funded by literally printing money instead of issuing debt per se?
Comment: @JonathanReez This would be impossible because Congress does not control the supply of money in the United States. Monetary policy is set by the Federal Reserve.
Comment: @sharur Currency and money are not the same thing. The US Mint makes currency, it does not make money. Currency is merely a physical medium for money.
Answer: No. The CARES Act and the December COVID legislation specifically made these grants, so they are not tied to tax liabilities, nor are they taxable.
Answer: Yes, all government debt is eventually paid down by taxation of the citizenry, or erased with a sovereign default. But it will be future generations, so like social security, not a problem for current generations.
Comment: "Future generations will pay it so it's okay" is a bad way to think about it. Besides, we don't have a time machine, so real goods and services can't be taken from the future.


Are dichotomous predictor variables appropriate in a quantile regression analysis?

Question: I want to model the changes in a dependent variable with non-normal distribution (e.g. abundance of micro-organisms) as a function of changes in dichotomous independent variables (e.g. gender, sick or healthy).
Is it appropriate to use dichotomous variables as a predictor in a quantile regression analysis?
Answer: There is nothing about quantile regression that makes dichotomous predictors inappropriate.
Often (not in your examples, but often) people dichotomize continuous variables. This is nearly always a mistake, but that's true, regardless of the type of regression.
Answer:
The distribution of the outcome is useless. You need to look at residual plots
Linear regression models have limiting normal distributions for regression coefficients, and the mean response as well
The mean-difference is often the natural scale for reporting change


Why is it hard to cool a mini-PC to room temperature?

Question: I have this passively cooled mini-PC that froze every few days. After a lot of investigation I realized that it was overheating (running android studio and such) so I bought a fan, an arduino nano and everything else needed to build a fan controller. It works well, my question is why I have to set the threshold temperature so high? I originally programmed my arduino to keep the inside of the case at around 32 - 33 degrees (celsius) but this was back in spring when the room temperature was in the low twenties. Then summer came and the room temperature went up to the high twenties and my fan started running crazy fast to keep that temperature. My current threshold is 37 - 38 degrees which is good enough for pc not to lock up but I don't understand why it has to be so high? I would've thought cooling the case to room temperature would be easy for the fan because the case is a huge aluminium heat sink and I thought it would want to reach thermal equilibrium with the room. The outside of the case is now 34 - 35 degress, way above room temperature. One more detail: the fan is on the outside of the case centered above the cpu and it covers about 40% of the top area of the minipc, it's a big fan.
Comment: Would [electronics.se] be a better home for this question?
Comment: @Qmechanic I wouldn't say so, because I was able to solve my engineering problem (the pc does not freeze and yet the fan is relatively quiet) I just didn't understand why I had to set up the threshold the way I had to. Read Niels' answer if you want, I accepted it because it's the response I was hoping for.
Answer: To extract large amounts of heat from a hot object requires that the temperature of the cooling medium in contact with the hot object be as low as possible, to maximize the difference in temperature between the hot object and the medium.
This is hard to do when using ambient air as the cooling medium, for two reasons. First, ambient air is "too close" in temperature to that of the CPU. Second, air is a poor heat transfer medium because its thermal conductivity is low and its specific heat capacity is low.
Efficient heat transfer using moving air as the transfer medium requires 1) maximization of the heat transfer surface area (typically done by adding cooling fins to the hot object), and 2) maximization of the airflow velocity over those fins, which requires a relatively powerful fan to drive the air (as in an air-cooled lawnmower engine, for example).
Neither of these can be effectively done with an ultra-slim laptop or mini-PC, especially since neither type of computer was designed with the capability of adding extra cooling capacity in mind.


approximating categories with continuous functors

Question: I am wondering about approximation and idealization.  Specifically, I am wondering if anyone has seen some work on the following.  In the semantics of programming languages we find Domains as a place to talk about iteration and approximation.  We can define a Scott Topology on the Domain and now our Domain-maps are continuous maps.  Next,we can see our Domains as categories and turn the continuous Domain-maps  into continuous functors.  If we push the idea further, we have continuous functors and a notion of approximation which is now over categories.  Lambek ponders the existence of the category of Sets.  What about approximations to the category of sets.  For that matter, what might it look like to approximate any well-known category like that of manifolds or FDVec?
  I realize the question is vague.  I wish I had a more concrete question, but my grasp of the material is too weak.
  Naturally, any thoughts on this would be most appreciated.
Comment: Here is the paper which outlines all of my ideas on using continuous functors in physics.

http://www.cs.mcgill.ca/~bsprot1/EvolvingUniverseFeb24.pdf

I realize this is not the place to post this, but some of the posters here might find it of interest.
Answer: As it happens, I just saw a paper about this very subject today -- Martin Hyland's "Some Reaons for Generalizing Domain Theory", which is concerned with precisely the generalization you suggest, in order to clarify the semantics of concurrency. This paper was apparently inspired by some work by Cattani and Winskel, but I found their work to be more categorically sophisticated than I could easily digest, and this one to be at about the level I can presently cope with.
EDIT: I also found a paper by Winskel in which he discusses the intuitions underlying his ideas, "Events, Causality, and Symmetry". This seems quite accessible to me.
Comment: Thank you!  In fact, these thoughts are coming from my contact with concurrency and distributed systems. To put a point on it, consider a bunch of computers, connected by the internet and thus not sharing a universal clock, and they want to consider themselves as part of a group G.  G is a set which contains the names of all the computers.  However, agreement is generally untenable in these kinds of asynchronous systems.  Thus the concept of a single universe of sets for all these computers is also untenable. Perhaps they can approximate it much like the approximations in agreement protocols.


Quasi maximum likelihood estimation versus pseudo MLE

Question: If I'm not wrong both "quasi" and "pseudo" denote the same thing, namely the optimization under wrong distributional assumptions. Moreover I think that the terms are not restricted to the assumption of normality. Is there an experienced reader who can confirm this? Cheers!
Comment: If you mean '*pseudo-likelihood*', see the first sentence [here](http://en.wikipedia.org/wiki/Quasi-maximum_likelihood)
Answer: Quasi-likelihood and Pseudo-likelihood mean different things. If the probability model is possibly misspecified, then the likelihood function is called a quasi-likelihood function (see White 1982 econometrica for example). In the special case where the probability model is correctly specified then the quasi-maximum likelihood estimation is the same as maximum likelihood estimation. The terminology "pseudo-likelihood" is not as established but typically means that independence assumptions are violated so that the the independence assumptions which permit the likelihood function to be constructed as a product of other likelihood functions are violated but the likelihood function is constructed as a product of other likelihood functions anyway. Thus, every pseudo-likelihood function is a quasi-likelihood function but every quasi-likelihood function is not necessarily a pseudo-likelihood function. See Besag 1986 "Analysis of Dirty Pictures" (Journal of Royal Statistical Society Series B, Vol. 48 for discussion of the pseudolikelihood function). These terms are not restricted to the assumption of normality.
Answer: The two names denote the same concept. See f.e. Hayashi's Econometrics. Concerning the second part I am not sure, but, normally, it is explained as the estimation if the model is misspecified (generally) - "in ways that do not affect the consistency of the estimator" (Davidson, Mackinnon - Econometric Theory and Methods.


Sword vs. Mace in armored mounted combat

Question: Interested mainly in medieval era heavy armored combat, and the relative strengths and weaknesses of the two classes of weapon, both on horseback and on foot. Valid topics include application, quality/cost and maintenance, weight, learning curve, etc.  Considerations vs other expected weapon types, wielded by mounted and unmounted opponents.
Comment: Since the point of contact will most likely be towards the tip of the weapon, I'd expect the mace to be superior, since it is designed to generate most force exactly there. They've both been used as mere slashing weapons, so learning makes not much of a difference. I lack the historical knowledge to give an expert answer, though.
Comment: @PhilipKlöcking I noticed in [Knight Fight](https://www.imdb.com/title/tt9454974/) that although the European swords used in the melee seem to be used exclusively for hacking/bashing, maces and hammers are specifically disallowed.  This is highly suggestive.  Swords, however, would typically have more range, be more versatile in defense, and can be used to penetrate gaps in armor, or pierce the armor of a prone foe that has been unhorsed, without much leaning that could potentially expose the combatant (compared to leaning in to bashing a prone, armored opponent on the ground repeatedly.)
Comment: @DukeZhou "swords used ... exclusively for hacking/bashing" It's almost as if those people are not trying to actually kill/maim each other. Or that a stab to the visor/join/back can do that.
Answer: A sword was much more expensive than a mace. A simple mace is a lump of iron strapped to the end of a stick. A sword needs high quality steel tempered competently. That's why longswords emerged only at late Medieval period - steelworking needed to be sufficiently advanced so they don't snap.
A mace is designed to combat armor - chainmail without gambeson is useless and even a fine fullhelm can't protect from knocking the person out.
A sword is lighter thus can be made longer - awesome for slaughtering villagers and archers.
A mace is clumsy to fence with thus to block another horseman's blow.
As always in war, a spear would defeat both in a duel.
I have obviously never tried to kill people with a mace while on horseback. But have 2 years of Filipino stick fighting and half an year of German sword fencing.
Comment: Excellent answer.  Could be accepted, but let's see if anyone else pitches in!  (Peter Lorge's "Chinese Martial Arts: From Antiquity to the Twenty-First Century" notes that the archeological record suggests pole-axes were most common battlefield weapon—easy to train and highly effective in context!)
Comment: Well, I hear you on uncited, but we're all speculating about this stuff, so a strongly supportable argument should be acceptable.  (In Red Cliff, there was some horseback halberd, but I hear you.)  My feeling is maces are durable, cheap, and one-hit kill to the helmet.  Easy to learn and bad for defense, but you are wearing armor...
Comment: @DukeZhou drawbacks of poleaxes: two handed and front-heavy(so can't be used by a horseman), require space to swing, I doubt they are any easier to learn than a sword(except "stay behind the first line of infantry and just swing up and down"). I don't think the answer is good(it quotes no sources): please leave it unaccepted.


Why can't Google Chrome load Flash plug-in?

Question: I can't get any Flash content to load on Chrome. When I try to watch a YouTube video or something like that, it just says, "Couldn't load plug-in".
Comment: Maybe this can help: [Youtube - couldn't load plug-in](http://askubuntu.com/q/250448/65926).
Answer: You need to update Chrome to version 24.0.1312.69 or later. This is a known issue which has been fixed in the said version. Run the following command in terminal:
<code>sudo apt-get update && sudo apt-get upgrade
</code>

Source: Google Chrome Forum Post
Comment: yep, that works
Comment: Oh no! Now it's falling out of sync w/ audio...See other suggestion about Adobe.
Answer: Try the Adobe Flash plugin, using the flashplugin-installer to get the Mozilla style NPAPI version (from the "nonfree" section of the Ubuntu repositories). It's frozen at version 11.2 but still has security updates and works fine with most sites. Plug chrome://plugins into the address bar and disable the libpepflashplayer.
Then try switching back to the Pepper Flash sometime to see if it works again.
Edit: My guess was that not all websites were compatible with the newest Flash, but it looks like it was just a bug (see other answer about upgrading Chrome). There were other issues with Pepper when it came to full screening video in a previous release, so it's not a bad idea to have both plugins handy for when you upgrade and everything breaks.
Comment: Now the latest pepper flash falls out of sync with video for a huge percentage of DRM content. So much for upgrading...keeping Adobe. Hmm...Amazon Prime has a message with the same suggestion, "Unsupported player..." Hopefully the networks will catch on with the same kind of browser detection, since I'm currently noticing that certain sites work better with Pepper while others choke on it--The variable bitrate streaming is better in Pepper when it works.


Bleeding a Cast Iron Radiator with No Bleeder Valve

Question: I am having an issue with a single cast iron radiator where it is not heating up at all. All other radiators are working fine in the apartment. A lot of people suggest bleeding the radiator, however, I can't seem to find any bleeder valve on this kind of cast iron radiator. I have attached a few pictures. Is there any other way I can bleed this radiator of the air that is inside it? I have already replaced the air vent valve but that didn't seem to help with anything. Thank you!
https://3.bp.blogspot.com/-NfI7FtvAEQY/WkJg3CxVrvI/AAAAAAAAA2Y/nOsuT1hfrzQceuvjgOK51ZBVbCEGjDS2QCLcBGAs/s1600/20171217_1629441.jpg
https://1.bp.blogspot.com/-5Mw-OPVvGTk/WkJg3SlDglI/AAAAAAAAA2g/iG4usuAwFeoW9THBssLzQq1ylnns-nW5ACLcBGAs/s1600/20171217_1630041.jpg
https://2.bp.blogspot.com/-h5LE1kPsoLY/WkJg3Powp6I/AAAAAAAAA2c/J_tOn8oxyDAKQvkTGkn39khAYYyQ5fnNgCLcBGAs/s320/20171217_1654431.jpg
https://4.bp.blogspot.com/-AELLpXEKI38/WkJg3jzqo8I/AAAAAAAAA2k/xOcrUjKNj-IqGe3sccYILdEWy3Bx90qjACLcBGAs/s320/20171217_1706331.jpg
Answer: The heating system is what is called a "1" pipe heating system. It is not a hot water system therefore the radiator does not require bleeding. I can not see  the make or model number of the vent on the radiator so I can't comment on whether it the correct type. Also make sure that the inlet valve on the left side is fully open and not partially closed. Be careful when replacing the vent on that radiator  or any of the radiators when the boiler is firing, steam can come out a cause very bad burns. Is this a single family home or an apartment? If it is an apartment call the building manager and have them replace the vent. If it a single family home make sure that you turn the boiler off before working on any part of the system.
Comment: This is a 2 family home where the same type of radiators is in the same position on the 1st floor. Since I own the building I was trying to see whether I can diagnose before reaching out to a plumber. I have confirmed the inlet valve on the left is fully open.Wondering if this valve is what is causing the issue. Going to see if the pipe underneath the valve gets hot at all.
Answer: Steam systems have a simple method of operation. Steam is generated in the boiler. The steam being hot rises and fills the radiator. The steam cools,condenses back to water and gravity flows back to the boiler. The vent valve serves two purposes, let the air out and keep the steam in. If the radiator doesn't get warm either the steam isn't reaching the radiator or the air is not escaping allowing the steam to enter. Feel the pipe before and after the shut off valve. Hot on one side and cool on the other the valve is closed or clogged. The vent appears adjustable. By rotating the cover with the small screw in it you can adjust the rate that the air escapes. The radiator also should be slightly angled with the vent side slightly higher than the inlet valve. Another possibility is the radiator vents are not balanced. They should be adjusted so that the radiator closest to the thermostat doesn't get so hot that the thermostat shuts down the boiler before the radiators farthest away get hot.
Comment: Thanks for the great idea. I am going to check the pipe before and after the inlet valve. This is something I did not think of earlier. If the valve is clogged I'll have to contact someone to get it looked at. Thanks for the immediate response. I'll keep you posted!
Answer: As stated above this in not a hot water system.  It is a steam system.  For safety sake KIM the steam is always above 212*.  It is very hot and can burn quickly. This being said I recommend the following:  First make sure the inlet valve is in the on position.  Top left to open.  Check for any change of operation in this radiator. Then turn the system off long enough to allow the radiators to cool and the house temperature to drop a few degrees. Carefully remove the vent valve on the side of the radiator.  (The system operates under very low pressure.  When the system is cool, there is no pressure in the system.  Upon start-up of the system, several minutes will be required to see any evident pressure in this radiator.) Turn up the thermostat.  Stand guard at the radiator.  If things are working properly, before long you will be able to see, hear and feel air being pushed out of the radiator to make room for the steam. In the beginning it will be at a very safe temperature.  If you start to feel air being expelled you know that there are no blocks between the radiator and the boiler. Allow the system to continue to run for a couple of minutes.  At a safe distance, observe the radiator vent hole.  You should, before too long, see actual steam being expelled from the radiator. The radiator will be heating by now and the steam expelled will be hot.  Turn the system off. Purchase a new replacement vent.  Any number of on-line vendors will be happy to send you one.
If on the other hand nothing happens with this radiator, you probably have a inlet valve problem.  Disconnect the radiator and move it to one side.  (Be careful, it is very heavy, it is top heavy and it has a narrow base.) Remove the inlet valve.  Preform the same test listed above. If you get steam, purchase and install a new replacement inlet valve. Reconnect all the piping with new valve.  Radiator should work as designed.
The vent valves are designed to be adjustable.  It the room heats too quickly, close the vent valve a bit.  If not quickly enough in relation to the rest of the house, open it a bit.  If it really lags behind, you may have to close the others in the house a bit to give this radiator higher priority.
Comment: I'm glad you said something about the steam being so hot. I am also leaning toward there being an inlet valve problem. I'm going to check the piping this afternoon to see whether the piping connected to the inlet is getting hot at all. It's possible I might have to shut off all the other radiators in order to kick start this one. Going to see what I come up with this afternoon. Thank you for the response!
Comment: If the branch that this heater is on is totally blocked, bad vent and or bad inlet valve, this pipe will not get hot because the air in the line won't allow the steam to go this way.  No steam, no heat.


What's the latest version of Boot Camp Assistant that can be installed on Snow Leopard?

Question: And also, where do I download it? Currently it says Boot Camp Assistant is version 3.0.4. And Software Update says everything is already up to date but I see some people say they have version 3.3 on Snow Leopard so yeah I'm rather confused.
Answer: Apple Insider says 3.3 update if for people using Boot Camp 3.1, maybe that's why.
Did you try downloading it directly from Apple's website ?
Comment: But that one you linked is a .exe, isn't it supposed to be a .dmg or .pkg? I can get the latest Boot Camp support software for Windows but the one confusing me is the OS X side, the `Boot Camp Assistant.app` in Utilities folder.
Comment: BootCamp is mostly a package of Windows drivers, the Assistant is just a tool the create a partition.
Answer: To get bootcamp related software and drivers best is to put the SnowLeopard Installation disk in the drive.

From the "Go" menu pick "Go to Folder…" and type "/Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/"
Then double click "BootCamp.pkg"
Run "Software Update …" from the Apple menu afterwards

http://support.apple.com/kb/ht3777
Note iMac 27-inch users may have a black screen after Windows 7 installation. The fastest way I have found to get rid of this issue and install drivers is to delete "Windows\system32\drivers\atikmpag.sys" this can either be done from Windows CLI using the Windows installation disc or by installing Paragon NTFS, Tuxera or else on OS X.
You may also opt for rEFIt http://refit.sourceforge.net if you want to boot on more systems than an OS X and a Windows.


Voltages at Secondary Winding in Centre Tap Full wave rectifier

Question:
Let N1 turns in the primary winding, N2 turns in the secondary winding.After centre tap, the turns ratio becomes half of secondary winding.In textbooks given that the voltages of the upper winding and lower winding are equal with that of the input with 180 phase diff.
but my doubt is that If the turns ratio becomes half, Voltage at upper, lower part of centre tap should be half that of the input.
how it possible to have the same voltage as the input?
Comment: You get half the overall secondary voltage across each half of the secondary winding.
Answer:
How it possible to have the same voltage as the input [on only half of the secondary]?

To achieve this the manufacturer would put twice as many turns on the secondary.
Since each half of the transformer secondary is only used on alternate half-cycles the wire rating only needs to be half the capacity of a full-wave rectified single-coil secondary. In effect the weight of the copper would be the same for a single-coil full-wave PSU or a split-coil double half-wave PSU. Similarly the same laminations could be used for either as the power requirement is the same.
Answer: If N2=N1 on the secondary, with a center tap, you get only 1/2 the voltage peak from each leg on each half cycle but for a fixed VA core rating you get twice the current compared to a full-wave bridge which acts as voltage doubler.
Therefore the Voltage output of a half-wave bridge split winding is \$N_s/2N_p\$ with peak voltage , \$Vp=\sqrt{2}~V_{RMS}\$ with a load cap and no load and often 10% conduction loss at rated VA load so the no load voltage is ~ 50% more than Vs(rms).


what is choking reactance in TLT?

Question: I was studying about the Guanella 1:1 balun and came across the term "choking reactance". What does this mean? Why does its value need to be large?
Answer: A "Guanella balun" is really just a common-mode choke.

simulate this circuit – Schematic created using CircuitLab
For differential-mode currents, the current on one half of the transmission line is equal but opposite the current on the other half. Likewise, the magnetic fields due to these currents is equal but opposite, so they cancel, and so there's no magnetic field at all. Consequently differential-mode currents see no inductance at all, and pass through as if the choke isn't there at all.
For common-mode currents the magnetic fields don't cancel, and so the choke looks like an inductor. This is the "choking reactance", inductance being a specific case of reactance. Ostensibly, we have the feedline where we don't common mode currents to flow (the "wrong" place), and we have some other place we'd like them to flow (the "right" place). For example in a coax-fed dipole, the "right" place is the leg of the dipole attached to the shield.
The idea with a common-mode choke employed as a balun in this case is to make the impedance seen by the common-mode currents on the feedline significantly higher than the impedance to the "right" place, whatever that is. Consequently most of the current will flow in the "right" place, and very little in the "wrong" place: the feedline.
Here's a similar but much simpler situation at DC:

simulate this circuit
Since R1 is significantly bigger than R2, almost all of the current will flow through R2. The idea with the choke is similar, except instead of resistances we are using reactances which are analogous for AC.
So in order for this balun to be effective, that impedance seen by common-mode currents, the "choking reactance" due to the transformer, must be significantly higher than the impedance to whatever the other place is where you'd prefer those currents flow.
Answer: I'm not familiar with the term "guenella", but:
A choke, in this context, is typically an inductivity with the function of suppressing high frequency signals/noise.
As inductivity, it has inductive reactance. Think of inductive reactance as the "resistance in effect at a specific frequency $f$", i.e. $2 \pi f L$, with $L$ the inductance.
Hence, the higher it is, the higher the resistance of the inductance to the frequency.
In the context of baluns, things might be a bit more complex: Since inductivity is the ability of something to store energy in the magnetic field, and baluns often are pretty much transformers, i.e. devices that convert electrical current to magnetic field change, and back to current, this size is tightly linked to the ability of a transformer to transport energy. I must admit that I'd need a lot more context to explain why its value would need to be large (a.k.a. slight ciriticism: give more background in your question!)
Comment: I believe "Guanella balun" was meant. It's a particular design.
Comment: thank you! and I read that choking reactance is formed by coiling TL to a ferrite core or adding ferrite beads around TL. So, does choking reactance refer to reactance due to ferrite beads or TL coil?
Comment: can't say, not enough context.
Comment: @KevinReidAG6YO ah, thanks. I also just saw Phil's answer :) yes, that explains the terminology!

what is choking reactance in TLT?