Biquad cascading frequency response

Question: I am implementing EQ lines in my filter. I need to do biquad with slope 24 db/oct, 36/oct and bigger so I would like to cascade several biquads. I am stuck with calculating frequency response of two biquads - now I am able to calculate magnitude and phase and draw one curve (peak filter).
Should I multiply this response by itself? Thank you in advance for the answers.
Answer: The application of a filter to a signal in the time domain is defined as convolution.  Convolution in the time domain is mathematically equivalent to multiplication in the frequency domain. So if we filter a signal, and then filter the output of the first filter, this is equivalent to multiplying the signal by both filters in the frequency domain. Therefor, this is equivalent to filtering with a third single filter whose frequency response is equal to the product of the first two filters' frequency responses. Because frequency responses are complex numbers, the resulting magnitude is equal to the product of the two input magnitudes and the resulting phase is the sum of the input phases.  This can be easily extrapolated for more than two filters as well.
Answer:
Should I multiply this response by itself?

The transfer function of some cascaded biquads is simply the complex multiplication of the individual transfer functions, i.e. magnitudes are multiplied and phases are added.
It's much more efficient to design the filter at the desired order and property and then break it into biquads than the other way around. If you want a 36dB/octave filter, just design a 6th order Butterworth filter and don't cascade three second order Butterworth filters.
Comment: Note that magnitude *as a ratio* is multiplied.  If you're using magnitude *in dB* then you add them -- because a dB is log ratio, and log this + log that = log (this * that).
Comment: Maybe it's just semantics but "magnitude" means linear amplitude and once it's in dB I would call it either "log magnitude" or just level.
Comment: It is "just" semantics -- but that doesn't mean it won't tangle people up.  "Log magnitude" certainly clarifies the meaning -- or saying "the magnitude is 20dBm" is pretty unambiguous.
Answer: Thank you for the answer, but i need some clarification - i think i am missing something important to draw this plot.
I am doing steps below:

calculate in for loop freq response of standard biquad (peak) and get array of complex responses
get abs() from each response and it gives me magnitude for given frequency on plot
do 20 * log10(magn) to get values in dB and i am getting for example peak line with min in -9dB
Phase i am calculating for each magnitude in first biquad using atan2(imag(freqRes)/real(freqRes)).

Then i am trying to calculate 4th order so cascading the biquad:

each complex response from previous biquad i am multiplying by itself (freqRes)^2
an multiply it by exp(2jphase) so (freqRes)^2 * (cos(2jphase) + sin(2j*phase)
and do an abs() and 20log() from this value

I am getting incorrect values - instead of curve with max/min gain in -9 dB and steeper slope i have -18 dB.
Maybe i am using phase incorrectly?
Comment: Hello @Mike91, I am assuming you are the OP. Instead of posting an answer as an extension to your initial question, please use the same account used when posting the initial question and edit the question there with the clarifications needed.
Comment: Hello @Gilles, actually i post questions as guest without account and don't have access to it.
Comment: it's best you open an account if you want a better follow up. Also to better comment on the answers people freely provide to your question, and if satisfied to upvote/accept those answers.

Biquad cascading frequency response


How to calculate the forces on members of a frame, due to a distributed pressure load?

Question:
I am trying to calculate the force sustained on the three labelled members of this frame (Members 1, 2 & 3). The frame will experience a uniform pressure of 1000 kPa in the area enclosed by the members. It will be screwed into walls on all 4 sides. You can imagine it as being installed in a 4m by 4m shaft. And the goal is to brace a door in the shaft, which might experience wind pressures of a 1000 kPa. Once I have found the force I will calculate the deflection in order to select the correct steel members for the frame.
For those curious, I just made up the numbers and the scenario but I am working on a similar situation and it's been many years since I studied statics. Any help or guidance would be appreciated.
Answer: The force on the perimeter will depend on the boundary conditions at the edges of each plate.  Determining the precise distribution of load at each point of the supported edges of the panels is going to be a headache if done by hand.  I would determine the maximum force per unit length of the edges and use that as a uniform linear force on the supporting members.
The way I would approach this is to use formulations from Roark's Formulas for Stress and Strain, 7th Edition, Table 11.4:
Edges Simply-Supported

Edges Fixed

You will want to solve for $R_{max}$.  For the Edges Fixed case, I believe $R_{max}$ is the same as for the simply-supported case.  Also, in the Fixed case, you will have to include the edge moments into your design.

Otherwise, if you're just looking for an approximate method to determine the force on the supporting members, first determine the total force on a panel:
$$F = (1000 kPa)A_{panel}$$
Then, take that force and divide it by the perimeter of the panel ($P_{panel}$) to determine your uniform load per unit length:
$$w = F/P_{panel}$$
This will give you a load analogous to the $R_{max}$ determined if you follow Roark's above, though this will be an average instead of the peak lineal load.  It will under-estimate the loads on the long edges and overestimate the forces on the short edges.
Answer: Adding to @grfrazee's answer, there is an intermediate method, less rigorous than Rourke but more precise than simply dividing by the perimeter.
That is the trapezoidal method, where one divides the load being applied to each supporting member. The only relevant information is the boundary conditions of the plate: whether it is free, pinned or fixed. Usually, slabs are said to fix each other, so if you have a beam supporting two slabs, one to either side, then both slabs are considered fixed on that face (the only exception is if one of the slabs is a cantilever, in which case the cantilevered slab is considered fixed but the other is pinned, since a cantilevered slab won't resist rotations due to loading on the other slab). On the other hand, if a beam is supporting only one slab, then that slab-face is considered pinned. If the edge of a slab is not supported by a beam, then it is considered free, of course. This method doesn't work for slabs supported directly by columns. It also assumes the slab is under uniform loads which cover the entire slab and is not strictly valid for other loading conditions (concentrated loads or variable loading within a slab).
Now, if two adjacent and perpendicular faces of a slab are equally supported (both are pinned or both are fixed), then one draws a 45° line starting from their shared vertex. If, however, one face is pinned and the other is fixed, then the line must be 60° (from the fixed face). These lines describe the load division to each supporting member. (After a quick googling, I've discovered some people simply consider 45° in all cases. Do as you wish, but I think giving more load to the stiffer member makes sense. That being said, I can't prove it, nor can I demonstrate why 60° is a good angle, I simply learned this in college).
Extending these lines until they fully divide the slab area, you now know the fraction of load that will go to each face.
This can be easily understood with an example such as this one:

Here we have three slabs A, B and C. Slab A is supported by beams B2.1, B3.1 and B4.1 and has a free end (the dotted line). Slab B is supported by beams B2.2, B3.2, B4.1 and B5.1. Slab C is supported by beams B1, B2.2, B4.2 and B5.2. In this example, lets just look at the load distribution of Slabs A and B.
Slab A is free on one face, pinned on faces B2.1 and B3.1 and fixed on B4.1. This is because the stiffness of slab B on the other side of B4.1 impedes (or at least limits) the rotation around face B4.1, while the torsional rigidity of beams B2.1 and B3.1 is considered insufficient to influence the slab's rotation. Given the rules described above, lines are drawn from the vertices between the faces. In this case, since B4.1 is fixed and B2.1 and B3.1 are pinned, the lines must be at 60° from B4.1. The remaining load is distributed between the pinned faces. The load distribution is therefore:

For the same reasons as described above, Slab B is fixed on faces B2.2 and B4.1 (due to the slabs on the other side of the beams) and pinned on faces B3.2 and B5.1. Since both B2.2 and B4.1 are fixed, the line between them is at 45°. Since both B3.2 and B5.1 are pinned, the line between them is also 45°. Since B4.1 and B2.2 are fixed and B3.2 and B5.1 are pinned, the lines between them are at 60° from the fixed faces. The load distribution is therefore:

Now one can calculate how much load goes to each beam by multiplying the "tributary area" of the beam by the applied load. In the case of beam B3, for example, the applied load is:
$$ q_{B_3} = \begin{cases}
\dfrac{A_3 \cdot q_A}{L_{B_{3.1}}} \text{ along B3.1} \\
\dfrac{B_3 \cdot q_B}{L_{B_{3.2}}} \text{ along B3.2}
\end{cases}$$
where $q_{B_3}$ is the uniform load on beam B3, $A_3$ and $B_3$ are the tributary areas found in the figures and $q_A$ and $q_B$ are the loads applied in each slab (in force-per-area units). The loading of beam B3 is therefore

In the case of beam B4, the loads would be
$$ q_{B_4} = \begin{cases}
\dfrac{A_4 \cdot q_A + B_4 \cdot q_B}{L_{B_{4.1}}} \text{ along B4.1} \\
\dfrac{C_4 \cdot q_C}{L_{B_{4.1}}} \text{ along B4.2}
\end{cases}$$
(C4 is the tributary area of beam B4 in slab C, which hasn't been drawn). Along B4.1 one must obviously add the loads applied by both slabs supported by the beam.
These equations are somewhat simplified, since they consider the loading along the beam to be uniform, which isn't really the case. The loading should actually be trapezoidal according to the tributary area. To calculate this more precise form, the loading on the beam is found by
$$q(x) = p \cdot h(x)$$
where $q(x)$ is the value of the distributed load at point $x$, $p$ is the area-load on the slab and $h(x)$ is the height of the tributary area perpendicular to the beam's axis (displayed as $h_{3.1}(x)$ in the second figure above). The loading therefore becomes:
Comment: Thanks for your help Wasabi. I have a question about this formula

qB3={A3⋅qA along B3.1, B3⋅qB along B3.2.

In this case is q, the loading, pressure or force? and is the parenthesis above indicating that the all the terms are going to be summed up? for example qB4=(A3.qA + B3.qB) ?
Comment: for the last line qB3=(A3.qA + B3.qB)*
Comment: also I am unable to find a reference to this method any where else. Do you have a source for the above?
Comment: @user3233, I have edited my answer with more information. I believe it should now be clearer. I can't find an absolute source, but googling "trapezoidal slab load distribution" comes up with a few articles and pages and whatnot. Looking at image results is also interesting. That being said, doing this search I've noticed that some people simply adopt 45° in all cases, even when one face is pinned and the other fixed. I think giving more load to the stiffer face makes sense, but I lack the arguments to really push that point.


What is required in a hollow "tube" to resonate?

Question: What is required in a hollow piece of tube of any shape to resonate and generate musical stable pitches and harmonics?
Comment: Aren't all tubes hollow?
Comment: You can get a tone from a paper towel core.
Comment: What do you define as "stable pitches" and "harmonics"?
Comment: Tubes don't resonate (much).  You need an oscillator to start things up, then match the tube **length** to maximize energy into a specified wavelength.
Comment: If you are talking about musical instruments, the tube is not the thing resonating at all. On a reed instrument, it's the reed. With brass it is the lip of the player. The tube simply determines the frequency of oscillation. (With some percussion instruments though, it really is the tune that oscillates.)
Comment: @danmcb- I think you have that backwards, it is actually the reed and the lips that create the initial air movement, but it is the internal volume of air that determines the actual resonance and the tube( in this case) that encloses that volume of air. And it is the air that does the resonating, whereas the reed and lips are merely vibrating.
Answer: user65726's answer has some of the basics, but to expand on that a bit:
The question asks for two things, which do not necessarily always come together: "musical stable pitches" and "harmonics."
First a little background.  To be clear, harmonics are not necessarily the same as overtones.  A harmonic is an overtone which is an integer multiple of a fundamental frequency.  Most 3-dimensional items do not resonate harmonically.  That is, they often have many modes of vibration that do not necessarily relate as integer multiples of some frequency.  If you strike a random hunk of metal with an odd shape, what will often result is a sort of "clangy" noise where different frequencies (produced by the different modes of vibration) all intermingle.
Many standard musical instruments instead depend on harmonic overtones.  The human auditory apparatus tends to group integer multiple overtones into a single "pitch" that we experience as the "fundamental."  For "clangy" sounds produced by 3-D objects (e.g., church bells), people may hear multiple pitches sounding together, rather than a single stable fundamental.
I'm assuming from the way the question is worded around "harmonics" that it is primarily interested in musical tones that generally create a single, stable pitch.
In that case, there are two possible kinds of resonators with a "tube of any shape."
The first kind is similar to most musical instruments that are tube-shaped (e.g., most brass and woodwind instruments, organ pipes, etc.).  Tube-shaped musical instruments resonate not only at a fundamental frequency, but also are close enough to one-dimensional tube approximations that they can generate multiple standing wave patterns that produce harmonics.  To generate good standing waves at multiple harmonic frequencies, the interior walls of the tube should be rigid and relatively smooth without sudden changes in diameter.  Either open-ended tubes or tubes stopped at one end can be used to produce standing waves (with different frequencies produced).
Straight cylindrical or conical shapes can be used (as are found in various musical instruments).  Musical instruments typically use a circular cross section for the interior walls, but it's possible to use other bore cross sections (like triangles, squares, etc.) through the tube and still produce stable harmonics, though the exact frequency spectrum produced may vary a bit.
There are some limitations on this type of tube.  As noted, the material must be somewhat rigid.  Otherwise, damping of the wave energy will occur too quickly and a standing wave may not be established.  The length must also be sufficient relative to the width to set up a standing wave.  One could imagine trying to blow across a small bowl or very short wide tube -- while it may be possible to create a high-pitched "whistle" in some cases, the sound likely won't be very musical and harmonic.
Another consideration is whether one is creating sound by blowing air (or using the resonance from air motion) vs. striking the instrument.  In general, a percussion instrument created by a tube that is struck will create most of its sound through the vibration of the material rather than the air column inside of it.  Since a tube like this will behave as a three-dimensional object rather than a one-dimensional air column (with its standing waves), the resulting sounds are much more inharmonic ("clangy").  Chimes and tubular bells are an example of this type of resonance, where the sound of the metal vibration is much louder than any air column resonance.  Church bells and handbells are often even more inharmonic, due to their more complex shape combining two-dimensional and three-dimensional modes of vibration.  Musical tones may be produced by these instruments, but they are less good at producing proper "harmonics" and may emit multiple distinct inharmonic pitches at the same time (sometimes referred to by various terms like "strike tone," "hum tone," etc.).
Moving on to the second type of resonator: If a harmonic sound is not required and only a stable fundamental resonance pitch is sufficient, a wider variety of closed tubes can be used to produce a Helmholtz resonator, also referred to as a vessel flute.  In a Helmholtz resonator, the overall shape of the tube is not as important as the fact that there is a relatively narrow opening, whereby a wave pattern is set up at the opening and depends primarily on the total volume of the closed tube/vessel.  If the opening also has a small narrow tube before entering the wider vessel, the characteristics of that tube may also play into the way the instrument resonates.
This type of resonance is responsible for the kind of sound which emerges from an irregular closed tube or vessel, like a bottle.  When air is blown across the opening, the resonance of the vessel can produce a sustained tone.  In this case for irregular shapes, patterns of harmonic standing waves are generally not created.  Thus overtones are typically hard to produce and the sound tends to be mostly a single fundamental pitch.  (These sorts of resonators were actually used historically to do a sort of mechanical Fourier analysis, as they would only resonate at pure tones that were then used to match up to a more complex sound.)
Comment: "A wider variety of closed tubes...": this includes the passenger compartment of an automobile with one window open, although the resulting frequencies are subsonic.  "Other bore cross sections": wooden organ pipes typically have a rectangular cross section.
Comment: @phoog - indeed. Subsonic but palpable.
Answer: Air! Which has to move. If the tube is struck, that in turn makes the air inside move - although the material the tube is made from may also vibrate.
By blowing either into or across the tube, the air inside starts to move. This makes sound.
Comment: Any shape will produce some sort of sound. Blow across the top of a bottle. Hit a metal tube. Blow a raspberry into any open tubing - try a watering can!! Shape can help make special sounds.
Comment: I thought spacial shape was required for that sound to become a stable pitch.
Comment: @Lorthas for the pitch to be stable, the physical characteristics of the resonating body must be stable.  For a tube, as long as the tube's length isn't changing, the pitch is going to be stable.
Answer: The key general feature for getting harmonics is that the sound generating mechanism be (effectively) 1-dimensional.  Whether straight, like a flute, or bent up, like a bassoon, all pitched woodwinds (and brass, and strings...) have a resonator/oscillator that is much much longer than its size in the transverse directions.
— By harmonics I mean overtones that are integer multiples of a fundamental frequency.
Answer: The two most important requirements for resonance are a stable enclosure volume (small or large) and air particles for an instrument that uses air to produce a tone, but solid materials also resonate, just consider a chime or cymbal, and size is still an important factor to consider when choosing a preferred tone. The shape of the internal volume may affect the sound and materials used to create the enclosure also come into play, consider a violin or guitar, but the two things that determine whether or not a tone is created or amplified by resonating air particles, is the internal volume of the resonant chamber and the air particles themselves.
Comment: actually the two requirements for oscillation are an energy source to sustain the oscillation, and some form of positive feedback that has a time constant to make the oscillation periodic. In the case of a wind instrument, that is the blower and the resonance of the tube, its length gives the time constant.
Comment: @danmcb- Are you confusing oscillation with resonance, it is my understanding they are two different things.
Answer: The tube needs to be able to entertain a standing wave without too much loss of energy.  A consistent cross section (preferably circular and of constant diameter, with comparatively inflexible walls) and two ends with significant reflection of sound travel in a "mode" of the tube (because they are closed or significantly wide open) are usually used.
Comment: "of constant diameter": Many woodwind and brass instruments have a conical bore.
Comment: The constant diameter 'fact' isn't so. Look at most brass instruments for starters.
Comment: No, the tube is designed to maximize energy out the bell-end!  Otherwise you'd have silent instruments.
Comment: Yeah this is wrong.  Consider editing or deleting.


How much energy is required to fuse two protons?

Question: What is the kinetic temperature required to fuse two protons in a plasma? How much energy does it release? What are the products of the fusion reaction?
Comment: Note that fusing two protons almost always yields a diproton, which is unstable and immediately falls apart.
Comment: How often does it fuse into Deuterium?
Comment: I do not know the exact number, but it is a vanishingly small probability that enables the Sun to continue fusing hydrogen for about 12 billion years.
Answer: This is answered in the wikipedia article on proton-proton chain reaction

The first step in all the branches is the fusion of two protons into deuterium (D). As the protons fuse, one of them undergoes beta plus decay, converting into a neutron by emitting a positron and an electron neutrino

$p + p → D + e^+ + ν_e$

The positron will probably annihilate with an electron from the environment into two gamma rays. Including this annihilation the whole reaction has a Q value (released energy) of 1.442 MeV.


What is the difference between ESV, NIV and NKJV

Question: My daughter is In college and is wanting to buy a new Bible. She has these three options.. I would like her to have one that is easier to understand but still accurate. What are the differences and what do you recommend for her?
Comment: is it for a particular class or personal use? which denomination is she a member of?
Comment: Welcome to CSX.  Do not forget to take the tour below.
Comment: Welcome to Christianity Stack Exchange.  When you have a moment, please take the Christianity Stack tour to learn more about us:  https://christianity.stackexchange.com/tour  This is how we are different to other sites: https://christianity.meta.stackexchange.com/questions/1808/how-we-are-different-than-other-sites/1809#1809
Comment: Here is a brief [Bible translation guide](https://www.mardel.com/bibletranslationguide) that discusses the differences. They employ different translation philosophies on a range from word-for-word to thought-for-thought translation. NIV would be a good combination of easy to understand and accuracy. ESV is more word-for-word (and thus my preference), but sometimes requires more work to understand.
Comment: If your daughter hasn't read Bible that often, for general understanding I highly recommend NLT, another thought for thought translation but more free than NIV, so the English flows better and it uses current idioms, leading to easier grasp of the main points.  It can then be combined with ESV for Bible Study.  The ESV Study Bible is one of the best today.  I regularly use both NLT translation and ESV Study Bible.
Comment: Hi Jenn, this probably can be a good and useful question, but it will attract personal opinion that can't be objectively vetted.  Taking out the part about "what would you recommend".  The only way alternative to get recommendations is if you give a little information about what you're looking to get out of it
Answer: Without knowing more about the reasons for your daughter wanting to buy a new Bible, and why it is she has only these three options, it is impossible to make a recommendation.  However, having background information about each of these Bibles will help her to come to a decision.  Below are links to three articles, which provide a brief history as well as pros and cons on each Bible. I have partially quoted from each article:

The English Standard Version (ESV) is a revision of the 1971 edition of the Revised Standard Version. The first edition was published in 2001 by Crossway Bibles, a division of Good News Publishers. The ESV Study Bible, also published by Crossway Bibles, was published in October 2008. It uses the ESV translation and adds extensive notes and articles based on evangelical Christian scholarship. Under noted theologian J. I. Packer, who served as general editor, the translators sought and received permission from the National Council of Churches to use the 1971 edition of the RSV as the English textual basis for the ESV. Difficult passages were translated using the Masoretic Text of the Hebrew Bible, the Dead Sea Scrolls, and other original manuscripts.  Source: https://www.gotquestions.org/English-Standard-Version-ESV.html
The New International Version (NIV) committee held to certain goals for the NIV: that it be an "accurate, beautiful, clear, and dignified translation suitable for public and private reading, teaching, preaching, memorizing, and liturgical use." The NIV is known especially as a "thought for thought" or "dynamic equivalence" translation rather than a "word for word" translation...  The greatest 'con' of the 2011 NIV is the inclusion of gender-neutral language and the necessity of interpreting rather than translating in order to present a more culturally sensitive or politically correct version.  Source: https://www.gotquestions.org/New-International-Version-NIV.html
Although the New King James Version (NKJV) uses substantially the same Hebrew and Greek texts as the original KJV, it indicates where more commonly accepted manuscripts differ. The New King James Version also uses the Textus Receptus ("Received Text") for the New Testament, just as the King James Version had used. The translators have also sought to follow the principles of translation used in the original KJV, which the NKJV revisers call "complete equivalence" in contrast to "dynamic equivalence" or "thought-for-thought" used by many other modern translations, such as the New International Version.  Source: https://www.gotquestions.org/New-King-James-Version-NKJV.html

I hope this information will be helpful.
Answer: First, because we are reading the Bible in translation (ie, not the original language) we must depend on the translators to properly convey the thought of the original text.  There are no perfect translations - all have their strengths and weaknesses.
For this reason, I would never depend on a single translation to convey all the subtleties of the original.  Always more than one and preferably several.
My favourite five are ESV, NIV, NRSV, NASB and NKJV.  I note the following about these versions:

All are produced by large committees that keeps them reasonably (but totally) free of sectarian bias
All except NKJV use NA27/28 Greek NT text.  The NKJV uses the Textus Receptus.  The differences between these is a matter of much unnecessary debate in some circles but the differences never affect any Bible teaching.
The ESV and NASB try to be a literal as possible (no translation is completely literal), while the NRSV and NIV are less literal but contain more polished English.
Many verses in all five of these will read almost word for word the same.  Where there are significant differences suggests that translators struggled and there is room for differences because our understanding is imperfect.

Hope this is helpful.  If I were making such a selection, I would buy all of them.
Comment: Upvoted as it is very helpful, but the differences between these do make doctrinal differences. Some obscure some clear doctrines in the Textus Receptus. See [this presentation titled "Battle of the Bibles", on this topic](https://www.youtube.com/watch?v=tNv-zzpIwBs)
Comment: Also, [this presentation, titled Changing the Word](https://www.youtube.com/watch?v=RqBEuxGY7DI), is the continuation of Battle of the Bibles.
Comment: You would make a great salesman Mac's Musings,   or perhaps you already are one.
Comment: Many thanks - I am not and have never been a salesman but thanks
Comment: @jlaverde - I am quite familiar with those presentations and they contain much misinformation and plain errors.  I have many of the documents they quote and they misquote many things.  They are a great distraction.
Comment: @Mac'sMusings Interesting. Would you be willing to share some?
Comment: Very happy to do that.  However, there is a HUGE amount of it.  Try asking a few questions here, or do you want to do something else?
Comment: @jlaverde - I am not prepared to sit through a two hour lecture (Changing the Word) without first knowing what Walter Veith's aim is.  The first part focused on the New World Translation and I can confirm much of what he says because I have a copy of the 2006 printing. Why should any Christian listen to the rest of what he says? What point is he trying to prove?
Comment: @Lesley Hello. The first part does not focus on the New World Translation at all. It focuses on the history of the Greek Manuscripts and what that means for all the new versions. It also focuses on Westcott and Hort, who created the Greek New Testament used in virtually all new versions of the Bible. Changing the Word shows you a great number of the changes. He shows the differences between the KJV (which came from the Received Text) and the New Translation which come from the Westcott and Hort Greek Text.
Comment: @Lesley - I have seen the video and I would not waste your time - mostly misinformation and wrong data.
Comment: @Mac'sMusings You keep saying that, could you at least just name the most egregious? You say HUGE amount, but have not even named one. Or do you simply not like it because it doesn't agree with your theology?
Comment: I have a large amount of information and many original references on this subject which I am happy to share.  This question is not the place.
Answer: <code>           RSV      NIV      NKJV
</code>
|---------------------------------------------------------|                          Thought for thought.                         Word for word
Whilst NKJV is more word-for-word, RSV is more Thought-for-thought. This implies that NKJV is nearer to the original Hebrew and Greek scripts but could be difficult to be understood whiles RSV is more self explanatory because the translators tend to communicate the idea of the original Hebrew and Greek scripts.. NIV on the other hand balances the two which makes it preferable to many.
I prefer NKJV mostly and crosscheck scriptures from RSV and NIV. It is a matter of choice.
Comment: By RSV do you mean NRSV?  I find the RSV very wooden and tricky.  The NRSV is a HUGE improvement in both accuracy and style.
Answer: I have used the NIV as one of my daily readers since the late 70's early 80's.  I would not recommend the latest version as the translators have ventured into the area of commentary on some verses.  If you read the older and latest versions side by side you will find the translation to be longer in the new version.
I started using the ESV several years back and find it to be an excellent blend of nearly literal but still easy to read.  When I teach I use the ESV as my primary teaching Bible.
I will run a comparative translation when teaching with my Bible software using the following translations: ESV, NIV 1984, NIV, KJV, NKJV, HCSB (now called CSB or Christian Standard Bible). Generally they read well together.  When there is a difference I find it more do to a word that is hard to translate into English.


Is there a way to get .deb files of the installed packages via apper?

Question: So I'm running Debian 9.1 with KDE and I'm using Apper for package management. Now I'm wondering if it's somehow possible to get .deb files of the packages I installed over it (or that are listed/registered in it) so that I can use them for offline installation on another machine. Is that possible? If so: how?
Answer: Apper is a gui for packagekit. Backends for packagkit is for example

apt  Debian and debianbased Distros.
portage  gentoo
pacman Arch and his derivates

and others.  So the deb's are in the folder
<code>/var/cache/apt/archives
</code>
I personally use the cache for my reserve notebook only to spare traffic. and both installations were identical. for that I use on main notebook aptoncd With apt-cdrom i add the medium as sources to the other.
For complete offline installation may apt-mirror to create a local repository the better way.


Back-up battery

Question: for a project I would like to design a system which would allow me to feed my application's logic rail from a back-up battery if the main battery would somehow stop functionioning (most likely due to depletion or some other exotic case).
The battery should should stay charged and opperational and only be used in an event of main battery failure/discharge to backup or send all data processed by the CPU. Also, this system should keep the battery disconnected when the device is turned off so the logic won't start working even when turned off. Please consider my block-diagram below.
Does such a thing exist, if yes, what's it called, if no, why do people not use it?
Regards
Comment: What you have described sounds almost exactly like any electronic gadget (mobile phone, laptop computer) that charges from an external power supply.  Just treat "MainBatt" as the external power supply.
Comment: Is switching time important? If so consider a ups...
Comment: @SolarMike it's important in the sense that I absolutely cannot lose any data stored in the RAM. The capacitor-bank on the SMPS is quite large, so if it's reasonable, I do not forsee any problems here. Do such small scale UPS exist? Had no idea, I will do my research, thanks.
Comment: @SimonB well, not really, it's an agv with a data processing unit. And in the event of a failure (discharged battery, damaged battery lead, idk,..) it should have a bit of back-up juice to upload, or at least store the processed data.
Comment: Then you need to look at the logic of the ups...
Comment: Try googling power path controller.
Answer: It's called buck-boost battery charger ( if reversible )
Renesas has a portfolio with this family, ISL9241.

Back-up battery


How to subscribe to or access Tridion stack exchange questions?

Question: I want to view Tridion stackexchange questions in my inbox or web page through .NET API or Web Services. Is this possible? How would you go about it?
Answer: I created a filter here: http://stackexchange.com/filters/34648/tridion-stuff
You can subscribe to it via RSS or Email via the form on the right
It includes all Tridion questions across the Stack Exchange platform.
Answer: Another possible way is to use OData endpoints. You can query using it. Some details
http://data.stackexchange.com/about
Even you can query OData using LINQPad
But unfortunately i could not found OData Url for this site, could be because its in Beta.
Please try to find out the URL if it make sense to you. Usual format for this is
<code> http://data.stackexchange.com/<community>atom
 http://data.stackexchange.com/stackoverflow/atom
</code>
Answer: You can hover over the tags on any Stack Exchange site to subscribe to them. I posted about this somewhat obscure feature on my blog (with screenshots!).
You could also geek out with Bart Koopman's Tridion dashboard/StackOverflow extension and adapt it to Tridion Stack Exchange.
Answer: I have a similar filter to Chris's: http://stackexchange.com/filters/38484/tridion
There is also a twitter account that tweets the questions automatically: https://mobile.twitter.com/stacktridion you could use the twitter api to query it.


Is it possible to earn all the badges?

Question: What happens when you earn all the badges?
By any chance, is there some sort of 'hidden' badge for earning all the badges?
Comment: At that point your badge count will reset and a banner will drop down with the text "Level 2".
Comment: Your mom will be very proud. Seriously, though, this isn't even possible on Stack Overflow; some of the badges are retired (like Analytical) or were never available for SO (like Precognitive).
Comment: If there is a hidden badge (not saying there is) then telling you about it would kind of ruin the surprise - wouldn't it?
Comment: It would require every tag to have a minimum number of questions, therefore it's impossible because the goal posts keep moving. Were you to manage it you'd essentially be set for life on the kudos factor alone. But, never gonna happen.
Comment: ...which is where all questions are displayed in ROT-13 and all [rate limits](http://meta.stackexchange.com/questions/164899/the-complete-rate-limiting-guide) are increased by 100%.
Comment: You get a signed picture of Jon Skeet giving you the thumbs up
Comment: I've heard level 3 is the even harder ROT-26 @JoshCaswell ... wait ...
Comment: It is ROT-26, @Bart, but it also uses the Unicode Dingbats table instead of the alphabet.
Comment: Closely related: [Should the "precognitive" badge be listed in the list of S\[OFU\] badges?](http://meta.stackexchange.com/q/71712)
Comment: Yes, I know it's not possible. That's why I asked. :P  What if?
Comment: "What will happen when you earn all the badges?" You'll banned for cheating, and then *all your badge are belong to me*...
Comment: I don't understand. Most of these comments are not useful and yet it's upvoted that apparently 'adds something useful to the post'. This is more like a 'like' button on Facebook where people for example compete who gets the most like for being the funniest...
Comment: You ask a question you apparently know has no satisfying serious answer to begin with, yet are surprised by comments of a similar nature?
Comment: This wasn't a joke or anything. I mean, why would I ask a question if I know an answer? And besides, these people including yourself know more about this website than I do. Not giving an excuse or anything but at least give me and other people (who are new to this website) a chance to get used to this website. Not all people can ask a question that will meet this website's standard all the time.
Comment: @user3315821 - no-one is stopping you from having a chance to get to know this website (or any of the other Stack sites). But part of "*getting to know*" means exploring and learning yourself. It's a little *early* in the day for you to want to be earning all badges - In fact you're a long way of earning *many* of them yet. Have a read through the help centre pages and search the site for previously asked questions. Then, if there's something on your mind of which there's no apparent info already present, ask away :)
Comment: I understand. But I've never said I want to earn them all. I was wondering whether it's possible to earn them all or not. And if it is possible, what will happen? But I know the answer now so thank you all.
Answer: It's going to be nearly impossible for anyone, save perhaps the founding members, to get all the badges, since you have to be a founding member to get a few. Also, you'd have to get all the tag badges, at which point you'd have millions or billions of rep..
Also, it's impossible to get a badge for having all the badges, since you don't have the badge that signifies that you have all the badges.
I sense a recursion joke in there somewhere.
Comment: I currently have a [Universal Set](http://en.wikipedia.org/wiki/Universal_set) in my [Bag of Holding](http://www.dandwiki.com/wiki/SRD:Bag_of_Holding).
Answer: I have to double check this, but I think earning badges like Unsung Hero and Tenacious would be mutually exclusive to this, since they would indicate a lack of voting on a significant number of your posts (a requisite for quite a few of the other badges). I'm not certain it's impossible, but you'd need to do it in a very planned and calculated way. I'm not so sure earning all of them is possible.
No, there aren't any hidden badges (period). We've been discussing the idea of additional gold and silver badges that wouldn't be on the badge list, but discovered by earning them or happening upon someone that had. By design, these would be extremely difficult to get. It looks neat on paper, but some feel strongly against the idea, so it's still just an idea at this point.
I've also got ideas for badges that sites themselves could earn, like 'Happy Place' for great new user retention or 'Speedy Gonzales' for consistently low median times to the first up-voted answer to new questions. These would hang on a different wall showcased more as community than individual achievements, while those that participated heavily in earning them could possibly get individual gold / silver badges for doing so.
All still an idea.
Comment: You don't lose Tenacious or Unsung Hero even if you later stop meeting the criteria, so that should be no problem. (I should know, I have them on SO.) Besides, there's no reason you couldn't have both a few really highly voted answers (to qualify you e.g. for Great Answer) and a large number of zero-score accepted ones at the same time. (The trick to getting those, should you want them for some reason, is to answer a lot of questions asked by low-rep users on unpopular topics.) On SO at least, though, Constable and Precognitive are the kicker.
Comment: Permanent secret hat will be so cool, you know. ;)

Is it possible to earn all the badges?


How is the host file actually used in unix/linux networking?

Question: I see on wikipedia that a host file maps IP addresses to human-readable hostnames, much like a DNS server. But does a local computer need to resolve IP addresses? Is the idea that you configure the hosts file for all of the computers on a network so as to customize/configure the network? (Kind of like for a local machine name in windows).
Answer: See the manpage of the hosts file, there are some interessting parts.
man hosts
...
   Historical Notes
       RFC 952 gave the original format for the host table, though it has since changed.

       Before  the  advent  of  DNS, the host table was the only way of resolving hostnames on the fledgling Internet.  Indeed, this
       file could be created from the official host data base maintained at the Network Information  Control  Center  (NIC),  though
       local  changes  were  often  required  to  bring it up to date regarding unofficial aliases and/or unknown hosts.  The NIC no
       longer maintains the hosts.txt files, though looking around at the  time  of  writing  (circa  2000),  there  are  historical
       hosts.txt files on the WWW.  I just found three, from 92, 94, and 95.
...

The file is read before a DNS or any other lookup is made (order defined in /etc/nsswitch.conf). Is is also needed to map the hostname and the localhost to the loopback address (127.0.0.1).
One can summarize it as follows:
It is a burden of the last computer decade, but still usefull.
Answer: Chaos's answer is perfectly accurate, but there are a couple additional use case which I felt worthy of mentioning.
Aside from containing localhost, it's also a generally good idea to put the machine's hostname in the file as well. This is so that connecting to the local machine via it's hostname is fast and doesn't need a trip out to the network. Some programs can do this operation a lot, and so the performance is highly beneficial.
Another use case is for fault tolerance. Whenever I build clusters I always put entries for all machines in the cluster in each machine's hosts file. This is so that if there's some sort of network connectivity issue or DNS failure, the nodes in the cluster will still be able to communicate with eachother.


Is butternut squash with veins OK to eat?

Question: I had two butternut squash sitting on counter for 2 months. One is the usual bright orange inside but the other had white veins. I think it is the low humidity in Arizona allowing the starch to seep out of the flesh. This happens to a lot of my longer kept produce like cantaloupe. Any other ideas? Thanks!
Comment: Hard to say without seeing it but my first guess would be mold, especially with the cantaloupe.
Answer: I know this is old but figured if you come across this again.
Squash generally last about one month after they are harvested. If the inner flesh contains any dark or mushy spots, discard it immediately.
I have had some white veins in my squash but they were just harvested and it tasted just fine.  Being that they are at 2 months old I would not risk it.


How is NAND Flash memory array organized?

Question: Could you please explain how memory array organization calculated? Here I have attached snapshot of 2Gb NAND flash memory array organization. I can't understand the calculation of 1 Plane (marked in yellow color), but I do understand the calculation of 1 block.
Comment: thank you very much for your correction of my sentence formation.
Answer: The image of the part number you have shared implies that its a 2-Plane NAND Flash chip.
A Page is 2,048 + 64 Bytes long, 64 such pages forms one Block.
So,
size of 1 Block = size of 64 Pages
                = 2,112 x 64 Bytes
                = 1,35,168 Bytes
                = 10,81,344 bits
                = 1056 Kb

Now, 1 Plane consists of 1024 such Blocks.
So,
size of 1 Plane = 1024 x 2112 x 64 Bytes
                = 1024 x 1056 Kb
                = 13,84,12,032 Bytes
                = 1,10,72,96,256 bits
                = 1,056 Mb

Since the device has two such planes,
    Memory size of 1 Device = 1,056 x 2 = 2,112 Mb.
Kindly note that 2112 Bytes each for Cache Register and Data Register are not being counted in the sum of total memory, since it is not a non-volatile memory.
Additionally, the advantage of having two blocks is:

Memory can be divided into two physical planes, odd/even blocks
Users have the ability to:
    <•> Concurrently access two pages for read
    <•> Erase two blocks concurrently
    <•> Program two pages concurrently
Provided that, the page addresses of blocks from both planes must be the same during two-plane Read/Program/Erase operations.
Comment: ya i got it clearly thanks . But my mistake i was not watched carefully the calculation of plane as byte to bit conversion.
Answer: This NAND Flash Memory is an example of 64bit system based modern flash memeory both fast and huge,the thing with the modern cards the company uses a standard system for making various sized/capacity chips, here the technology PML 5(Page Map level 5) is used for extended address handling,A page is a virtual memory block in device hand hence the basic page size according to your Fig. is.=(2048 +64) or (2K + 64)
     where  2K=2^10
=64 x 8 bit = 64 bytes(these value really depend upon the page table structure (PML5*)        =2048*8 bit=2K* 8 bit=2K bytePML is a type  for the page tables structures.For more info on IA-32 structure see Physical Adress Extension.
Now lets see some details as you can see that a page has a total size of   2K+64 bytes
Now you see that we are using Segmented Memory, A segmented memory has two banks ,one bank is even bank and the other is called the odd bank containing all the odd addressable byte.You can read more about Memory Segmentation.
A whole block has 64 pages, these may vary per design,but they are standard for 64 bit systems.
To sum overall discussion
Device has 2,048
blocks organized as 64 ....a total of 2,112-byte (2,048 +
64 bytes) pages per block. Each block is
132K bytes (128K + 4K bytes).Each plane has 1024 blocks per plane and 2 planes per card thats your device.

So why use this system,often Companies use these blocks,they use standard memory addressing page structure for all the cards hence while moving up the total capacity(2GB to 64 GB) all they have to do is just add one stack of die over the other,as the system design remains the same,hence its adds modularity in die designing.
* I really doubt the Technology used its just for refrence of the OP I have specified a category


Do Jews think that all the unbelievers would go to hell someday?

Question: I wonder whether Judaism teaches that those unbelievers or those who are Jews but nevertheless lead a sinful life would go to hell someday when judgement time comes.
Comment: Note that while your question seems to draw a distinction between "unbelievers" on one hand and "those who are Jews" on the other, the status of being a Jew is not defined by belief. Someone whose mother is Jewish is Jewish regardless of belief. It's also possible to convert to being Jewish, and that presumably requires belief, but once a person has changed status through such conversion, that's also permanent regardless of belief.
Comment: Voting to reopen. The other "duplicates" don't really address this exact question with the possible exception of the first part of [Do we believe in Heaven and Hell?](http://judaism.stackexchange.com/questions/7401/what-are-the-characteristics-of-sheol/7413#7413). In any event, in none of those questions is this really answered.
Answer: In a word: no.
You're using a great deal of Christian wording here, so let me state the way it's phrased from a Jewish perspective, and hopefully this helps:
Barring some truly extreme cases, hell only lasts a maximum of twelve months before a soul can move on to higher realms.
Jews believe that all Jews, except for a few special cases, have a share in the World To Come; as do righteous non-Jews.
Recall that Judaism doesn't expect non-Jews to keep Judaism, just the Seven Noahide Laws.
Comment: Isn't it also true that Judaism does not even require belief from non-Jews, just abstention from idol worship or cursing God?
Comment: "except for a few special cases" does include certain important beliefs (The Mishnah lists a couple, the Rambam a few more).
Comment: It seems that you mean "chasidei" vs. "chachmei" ([Hilchot Melachim 8](http://www.mechon-mamre.org/i/e508.htm):14), and that, at least according to the Rambam, basic belief is indeed required for a gentile to "have a share in the World to Come" (whatever that means). I'm not sure what the implication is of saying that a gentile who keeps the 7 Mitzvot without belief is a member of "chachmeihem," but it's presumably at least neutral.
Comment: This is true, except for guys named Squidjibob... Halacha doesn't like him very much. (sorry, couldn't resist)
Answer: If by "unbelievers" you mean those who are not Jewish, then the answer is "no".  The Talmud at Sanhedrin 105a says that the righteous of all nations shall have a place in the world to come.  The question is "who is righteous?"  As noted, a gentile who keeps the seven Noachide laws in all of their details is said to have attained the level of righteousness of the High Priest in Temple times.  Baba Kamma 38a.  Maimonides (the "Rambam") at Hilchot Melakim 8:11 confirmed that a gentile fully-observant of the Noachide laws has a place in the world to come.
If by "unbelievers" you are referring to apostate, atheistic, or agnostic Jews, then the answer is "it depends."  If the person is an atheist or agnostic because he's never had an introduction to Judaism or knows what the commandments are, much less how to observe them, he could not be judged guilty for violating laws he did not know.  On the other hand, someone who is especially sinful, and more so, one who causes others to sin, e.g. an adulterer or one who embarrasses others, according to some views, are doomed in Gehinnom forever.  Baba Metzia 58b.
Another view, that of Hillel, is that (as Shalom noted) that the worst of sinners will suffer in Gehinnom for 12 months and then their souls will be destroyed into dust that will blanket Heaven and be walked upon by the righteous.  Rosh Hashana 17a.  Less aggregious sinners, however, will spend no more than 12 months in Gehinnom and then be raised up to Heaven. Ibid.
In addition, there is a view that eternal punishment exists for those who attack and defame Rabbinic Law.  It is said that they will be boiled in feces for eternity.  Gittin 57a.  Which of these views is correct, no one is sure.  The purpose of such speculation appears to be to motivate Jews towards certain behaviors rather than giving you a precise picture of what to expect.
Answer: There are many different views on these matters. The Rambam in Moreh Nevuchim seems to take an original view that there is no such thing as hell. The righteous and wise will reach a level where their soul continues after death, but the wicked will cease to exist. The Rambam seems to hold that those who do not have the right beliefs will not be able to be continue to exist for eternity. On the other hand, if someone sinned but overall was righteous, then he should be able to acquire olam haba.
Comment: http://seforim.blogspot.com/2010/09/no-hell-below-us-controversy-over.html
Comment: Beliefs or actions or both?
Comment: @ArielK, see above link for discussion on Rambam's view towards hell.
Comment: What are those "right beliefs?" Notice that God seems to speak favorably about Cyrus, a worshiper of Marduk. http://answers.yahoo.com/question/index?qid=20100308225829AA6TX8v Cyrus is a nice king that allow jews to return from babylonian exile. It's just that his God is simply not YHWH for obvious reason that his parent is not jewish. What about chinese that worship Shang Ti? Christians now "market" to chinese that Shang Ti is the same God with YHWH.
Comment: @user4951, Cyrus was a Zoroastrian dualist, not a believer in Marduk. That is why Yeshaiah is given a message to leave around to be given to Cyrus that reads "יוֹצֵ֥ר אוֹר֙ וּבוֹרֵ֣א חֹ֔שֶׁךְ עֹשֶׂ֥ה שָׁל֖וֹם וּב֣וֹרֵא רָ֑ע אֲנִ֥י ה֖' עֹשֶׂ֥ה כׇל־אֵֽלֶּה׃ - Giving form to light and creating darkness, making peace and creating evil -- I Hashem do this." (45:7) As opposed to the Zoroastrian demigods of Light and Darkness, who are also gods of Good and Evil.
Comment: @user4951 but Zoroastrians do have a single Creator, Ahurah Mazda, standing behind them. It's just that they explain evil by assigning its creation to a separate demigod than good. (Actually, I can't get a clear picture from Googling whether good is attributed directly to Ahurah Mazda, or if AM is thought to have emanated two demigods. And it actually matters, because a lot of those demon names in the Bavli are actually references to Zoroastrian demigods.


How do you remove a stuck glass door knob?

Question: I have an antique glass door knob I am trying to remove.
I have removed the screw at the base of the door knob and have tried to unscrew the door knob.  It is stuck.  I have tried spraying WD40 to loosen it up, but that didn't work.  Don't care if I have to break the door knob.  It is being replaced.
Any help would be great.
Thank you./
Answer: It is definitely a threaded connection. The threaded rod (spindle) looks something like this:

Now that the set screw is out, lean on it (especially if you don't care if it breaks).
Image source
Comment: Seems a shame to break an antique glass door knob. Some antique dealer might be able to sell it to someone who wants it.
Comment: @JimStewart That reminds me, either knob can be removed. OP may want to try the other knob too.


Let John and I go or Let John me go

Question: Let John and I go is correct or not? Or should I use Let John and me go?
Which one is correct and why?
Here "I" is the subject pronoun and "me" is object pronoun. Above John and me/I is the subject of this sentence so I think John and I is correct. Please correct me if I'm wrong.
Comment: ✘ *Let **I** go.* ✔ *Let **me** go*.
Comment: The context doesn't change the grammar. You can't say *Let I go*, because the sentence requires the objective form, not the subjective form. This is explained in the answers there, all of which say the same thing as the answer here.
Comment: No. Context is different
Comment: Just want to mention that Huddleston & Pullum in CGEL (p. 934) devoted a special section discussing the acceptance of "let's you and I" in informal standard English. A bit different because the OP's question doesn't have the *'s* but it is pertinent to some extent.
Comment: @user178049 Hebrew has a first person plural imperative that is often translated into English as "we shall do X" or "let us do X", but which in the original is an order (or at least a request), not a statement of fact. "Let's you and I" is an attempt to create such a tense in English.
Answer: "Let John and me go" is correct.
You are right that "I" is used for the subject and "me" for the object. Where you got tripped up is supposing that I/me here is the subject. It's not: it's the object.
This is an imperative sentence. In an imperative sentence in English, the subject is often not stated. It is assumed to be "you", that is, the person that the speaker is talking to. In this case, the person is demanding or requesting that "you" allow John and "me" to go. "you" is the assumed subject. "You" are doing the "letting go". The people you are letting go are "John and me". So "John and me" are the objects, and therefore "me" is correct.
Comment: Your explanation seems right to me.

Let John and I go or Let John me go


How does nitinol shape memory wire work as an Antenna in 60 MHZ whip antenna?

Question: I'm trying to make a body whip antenna for some friends of mine running at 60 Mhz at 10 W power. We are in the military, and we are trying to make an antenna that can be routed through our gear to prevent a massive bulky antenna from hitting us in the face. The downside of this, is the antenna is relatively close to the ground at shoulder height, so it wont have the same range as an antenna that extends about 1-2 feet over the shoulder. Usually I would use a RG58 cable as an antenna base material, but its flimsy and if left with no support will just fold onto itself. I was hoping Nitinol wire might be good to use because of the shape retention attributes that will keep it up in the air. Anyone with any experience with Nitinol wire have any advice?
Comment: Thanks for the input, I'm new here and didn't know how detailed it needed to be. i updated the question.
Comment: Hi, please can you edit your question to explain in more detail what you mean by: body whip, antenna base, line of sight? These don't make sense to me as written. What problem are you trying to solve with Nitinol wire - will you be bending and then heating the antenna? Are you trying to mount the antenna on a backpack or on a person directly?
Comment: Nitinol's special property is that if you bend it will unbend itself when heated. I don't see why you would need this. *Any* thick enough metal wire will hold itself up - even a coathanger
Answer: A very general rambling answer that might help a bit. Body-worn and low-profile antennas have a long and unhappy history - they generally don't work very well. The main factors are that:

the body is not a great conductor, so it absorbs some of the radio power
the person and equipment is usually in the way of the radiation, so it is directed more in some directions than in others
the configuration is not stable, so the resonant frequency and other properties of the antenna are always changing. Either this requires re-tuning (example automatic tuned antenna) for different situations, or it requires a low performance broadband antenna that doesn't change performance much when it's moved around.

So I'd always recommend getting the antenna as high up as possible. At 60 MHz, you should ideally have 3-4 feet of whip antenna, shortening that by half will cost you maybe half the range.
Antennas are always first of all a mechanical challenge. I've spent years working on ways to make them flexible and impact resistant, but stand up straight. They can either be flexible over the whole length, usually a fairly thin stainless-steel whip or a "tape measure" antenna; or they can have some sort of base-mounted spring or break mechanism that allows them to fold or hinge at the base. I've made both for manpack radios - springs store a lot of energy so the thing tends to whip back and forth and hit you on the helmet when going through a doorway. Break mechanisms (also seen on some road island chevron/reflector poles) have cables and springs; they're heavier but can respond better.
For the whip itself - we'd always buy some pre-existing metal whip, actual tape measures, or a fibreglass tube, not wanting to get into the metallurgy ourselves. There are a lot of SS whips on the market, you can choose a diameter and taper to suit you. You could also use something made of plastic, wood, carbon fibre etc, with the antenna wire taped to it.
The Nitinol itself doesn't seem to offer any big mechanical advantage, unless you plan to somehow re-heat it. If you find it does - by all means use it. A small caution though - it might be much less conductive than steel or copper, and further reduce the transmitted power. It's hard to find good data but it seems to be about 100x less conductive than copper, which puts it close to generic stainless steel, so probably not a big deal.
Last thought - we are in an amazing new age where anyone can own a network analyser - for less than \$100! So if you want to experiment, get a NanoVNA, almost any one will work for 60 MHz, and a handful of cables and connectors from amazon etc, and start trying things. You can use regular stainless steel wire first for electrical tests. Look for a clear dip in the VSWR near your frequency, that moves around when you walk close to a wall or metal object. Once the antenna is somewhat tuned for your frequency, you can set up simple tests with a \$20 SDR and a laptop, to compare the transmitting performance of various different antennas. [but ask a new question about that]
Comment: Thanks! I know that there are disadvantages to the body whip antennas in relation to the body taking some of the signal and not having long range. I was thinking of using the re-heat process to make the Nitinol straight and attach it to the rg58. That way I could undo some Velcro and have the memory function, to have it "snap" up and have longer range. I was just hoping to see if I'm being an idiot of if my idea has any merit.


Synchronous Limit and asynchronous Limit in apex

Question: can anybody tell me that what is difference between Synchronous Limit and asynchronous Limit in soql governor limit in apex?
Answer: Synchronous means calling the apex class using Visualforce page, Trigger, Execute Anonymous of dev console. These type of call hold the process until they complete and run in main transaction thread.
Asynchronous operations are calling apex using batch, Future methods. These process run in background and don't affect the main transaction thread. They run is separate independent thread with their independent governor limits from main transaction.

For both cases SOQL Limit is 50,000 records per transaction.
Comment: Synchronous: user or calling application is stalled until a response is received. Asynchronous: user or calling application can continue using the system while the process runs in the background.
Comment: Thanks for the concise definition. I was looking for it. @sfdcfox


How can I log validation error in asp .net

Question: I need to log validation error in asp .net so that I can know which fields users often input wrong data.
Answer: You could add a custom validator to the page that runs on the server and logs the pages validation errors to a specific data source.
Obviously this wouldn't be great for the long term but would allow you to temporarily monitor any fields that are being filled in incorrectly.
In the validator you could if you already have validators on the page, check which ones are incorrect or if you currently don't have any validators write some custom code to validate the fields.
Comment: I agree with Pasha and like I said this would ideally be for a short period of time and smaller projects
Answer: Apart from SCB's answer you should really look at logging mechanisisms out there. Many people for example use Log4Net (Free), EnterpriseLibraries (Microsoft). There are various tools out there. I have used both of the above. But in your scenario the question would be:

On how many pages do you want to log them and how many validators there is per page.

If your scenario is a small one I would not bother doing to much work around it but if it has to potential to grow past the current small scope to be mid to large scale I would recommend you look at the above suggestions. If you are worried about costs try Log4Net.


Is the idea of positions on one issue showing the likely position on another issue a new phenomenon?

Question: I want to know about the fact that certain positions seem to be tied to ideology which is in turn tied to partisanship. For example, the issue of gun control. Supporting gun control is strongly tied with being a liberal Democrat and opposing it is tied with being a conservative Republican. I have noticed that with websites and how positions fall ideologically. Is the fact that certain positions are proxies for other positions on issues that may not be related a new phenomenon?
Comment: I suspect there are two explanations. One is an age of hyperpartisanship, where people support (or oppose) an idea simply because of who opposes (or supports) it. Another is that a great many questions are **not** actually independent. Much can be characterized as "freedom from" vs. "freedom to" -- do you believe that man is an individual being, and others should leave him alone, or do you believe that man is a social being, only able to prosper in the community with others?
Comment: The 2 party system of the US has forced position bundling for a long time. Polarization might be cutting down on issue heterogeneity. A highly demographically targeted news medium might be raising awareness of once unconsidered positions as well. I do think there's a recent greater awareness of many issues and most also seem to know what side they "should" be on. This could be because political identity is stronger than it used to be, replacing concepts like trades, origin, and religion as the measure of man. None of this is new, but it could be strengthening.
Comment: I swear you've asked questions before (and that your account was more than three days old).
Comment: I think this is a good question and am interested to know the reason for downvote(s) and close votes, beside the suspicion that this has been asked before. Coalition building explains the need for this phenomenon in a two-part system and there are various reasons why it seems moreso in say the House of Representatives than in the past (whither the blue dogs and the liberal Republicans?). Really the question should  be  does the common but  involved person display this more than in the past?
Answer: If I understand the question correctly, it is about ideological coherence or consitency. The more ideologically coherent the base of a party is, the more thoroughly its followers will agree on a list of ideological issues. Issues like gun control and, say, abortion or deficits are superficially unrelated but ideologically connected. On the one hand, the party system has always implied a degree of ideological coherence. However, yes, this has been increasing for some time due to partisan polarization. Here's a helpful bit from Pew Center on this.


How to search keywords, filtered by - most popular, in (x) years/months on YouTube or Google search?

Question: How to search YouTube (or via search engine like Google to reach YouTube) keywords, filtered by - most popular, in (x) years/months?
Answer: From Youtube
First type your keywords and click search. After getting the results of your search, you can then sort by clicking the filter options and selecting options related to dates, sort by "View count" for popularity.
You can also use the before and after keywords to restrict the range of search. For example, to search from videos from February 2020, type: before:2020-03-01 after:2020-01-31.

From Google Search
Type your keyboard followed by site:youtube.com to restrict the search to only youtube. You can then click on Tools to display more options. You can customize the date range and the duration. The begore and after options also work with Google Search.
Comment: Google `google-fu`.
Comment: Men i can't say how thankful I'm in first place, to find this kind of answers is like finding unicorn. Now when i found one myself, i would like to hold you for a minute, and ask, where you yourself learn these kind of things, maybe link to some kind of articles or something? I would love to learn, everything what is deeper then the surface, about in first place 'Medicles' for Youtube and search engines. This forum defiantly goes to first step for me.


Unpublished manuscript

Question: I found some stories my mother wrote and they were never published. She is deceased. I know I can send them in but can I edit them before I do?  She wrote them in the 1960s on a manual typewriter and they need editing. I would want to publish them under her name.
Answer: Assuming you either are the sole copyright holder through explicit inheritance, or have the blessing of her other heirs (such as your siblings) to do this, then yes, you can edit her manuscript, have it published under her name, and credit yourself as the editor. See for example the Silmarillion (written by J. R. R. Tolkien, edited by Christopher Tolkien).
In case there are other people who could claim the rights, though, and don't agree with you on this, then you can't either edit or publish the work against their will. This isn't just about money - the copyright holder is entitled to decide whether the work can be published at all.
Answer: Absent a specific bequest in her will, the literary rights belong to all of her children — assuming she wasn't married or that her husband pre-deceased her. It could get quite complicated, otherwise.
When she died, her rights transferred to her estate, so all of her inheritors have a claim moneys from publication — again unless there was a specific bequest or the executor specifically gave the rights to specific inheritors.
Copyright protects the manuscripts from 70 years after the date of your mom's death. Editing your mother's manuscript can extend the copyright date.  It gets complicated. The estate of Anne Frank extended the copyright past the 70s year limit of her death by giving her father authorship credit since he edited the work, extending the copyright.
Its not a detail you need to concern yourself with at the moment. Its a matter for your literary agent and publisher to understand. You can always pay a copyright lawyer to provide the specifics.

Unpublished manuscript


Installing ESXi 4.1 inside vmware server 2.0.2

Question: I have tried several times running ESXi 4.1 inside vmware server 2.0 installed on Win7-64 bit.
The problem is that the installation is stuck on welcome screen asking to press enter to continue (or Esc or R to repair). Nothing seems to let it proceed. I have followed all the suggestion illustrated.
Any other idea? Thanks a lot.
Comment: Thanks MisterJaytee. Worked, at least in so much as resolving the keyboard issue - then came "F11" time - simply received (in summary format):
"vmware esxi 4.1 installation:
Installation operation failed!

The installation operation has encountered a fatal error:

Unable to find system image to install. This is due to the image not being mounted correctly or the CD-ROM not being supported operation
.... record info ... before rebooting ...
supermicro, x7dcl, 0123456789, phoenix technologies ltd...
 reboot".
Found sites that talked a lot about corrupt ESXi4.1 installer downloads - n
Comment: Thanks my VMware ESXi 4.1.0 installation works.  I'm using VMware Workstation 6.5.4 on Windows 7 Pro x64 host.
Comment: What's the processor, have you got the VX bit enabled?
Comment: Yes, VT is enabled and the vmx config file has been modified as stated here (http://serverfault.com/questions/28399/how-to-run-vmware-esx-or-esxi-in-a-virtual-machine/163376#163376)
Processor il Core 2 duo P8700.
Thanks
Answer: I know it's a long time since you posted this issue, but I had the same issue myself.
It seems that a lot of people are having keyboard problems with ESXi 4.1, but the main resolution has been to plug in a different kind of keyboard - not very useful if you're trying to install ESXi on top of VMWare Server.
Anyway, taking a slightly different approach, I experimented with the kernel boot parameters and I found that adding acpi=off to the command line allowed the installation to continue.
So to do this, at the VMVisor (ESXi) boot menu, press Tab. Change the command line to read:
mboot.c32 vmkboot.gz acpi=off --- vmkernel.gz --- sys.vgz --- cim.vgz --- ienviron.vgz --- install.vgz
You should now be able to press Enter at the appropriate point and continue your installation.
After installation, you'll find the keyboard doesn't work again. This is okay as you can do everything from the VSphere Client anyway. But if you want the keyboard to work at the console, then first install the VSphere client.
Then connect to your ESXi machine and click the Configuration tab.
Under Software you should find an Advanced Settings option (scroll down if you can't see it).
Select this option then click VMkernel.
Now uncheck the box that says VMkernel.Boot.ACPI.
And click OK.
When you Reboot your ESXi machine (you can do this from the VSphere Client), you should now be able to use the keyboard at the console.
Comment: I'm glad someone else benefited from my hard work! If that's worked, could you tick the answer. Thanks.


How to export a Bezier Curve into Unreal Engine 5?

Question: I'm having trouble trying to export three Bezier curves into Unreal Engine 5. My mesh is a monster that has tubes coming out of his helmet into other areas of his body. The curves move dynamically when animating so Bezier curves are the only things I can think of to make it look realistic. However, when I export the mesh to Unreal Engine 5, the Bezier curves do not import. Ive tried FBX, GLD, ABC, DataMax for unreal, and any other format that you can think of. I've tinkered with countless settings trying to get it to export. I've applied all my transforms in Blender to make sure the scaling was right. I even translated the units from Blender to Unreal. I have spent hours digging through the internet with no luck. Any help would be appreciated. Thank you.
Comment: You will not be able to export bezier curves that can dynamically deform. Common solutions for such thing are usually to either use normal mesh deformed by bones (bones can follow a curve if you want), or use the game engine's own curves/ropes dynamic systems.
Answer: There is a plugin for Unreal Engine 5 called Blender Curves Importer.
It specifically deals with exporting bezier curves and importing them into Unreal Engine as USplineComponents.
If you have a different type of curve in Blender, you can just convert it to bezier curves before exporting and importing in Unreal Engine 5. I think it maybe useful for your case.
https://youtu.be/HKUX5LKELMQ
Answer: Convert curves into mesh (in any way, modifier, extrude or bevel, its not important).
You can animate in 2 ways:
Rig and Bones
But I guess its not an option in this case.
Shape keys
Define shape keys in blender. Constraints do not work unfortunely.
Export FBX and to Unreal engine you import model with "Morph targets".
Then you should be able to drive morth target in UnrealEning to match animation.


Why is Android phone shutting down by itself?

Question: Phone is Samsung Infuse 4G with Cyanogenmod 11 (Android 4.4). On a few recent occasions when I check it in the morning, I find that it's powered off. I start it up again, and it shows plenty of battery charge (75% or more). Is there a log or something that I can look at that would explain why it has shut down?
Answer: Had the same problem. Solution:
Boot into CWM/TWRP Bootmenu (pressing "Volume up" Key and Power Button) while starting the phone -  and chose to clear "Dalvic Cache and Cache". Both will have no impact on your installed software or data. So it is quite safe to do.
After clearing reboot. The next restart will take a bit longer because these caches have to be rebuilt again. Solved my problem with random shutdowns.
Another possibility could be a dead battery. Especially if charging values change between full loading (100%) and after rebooting (90% or similar) ...
Answer: Well, it's well known problem for Samsung phones and tablets:
Read carefully: http://androidforums.com/threads/randomly-turning-off.312084/
One of possible solution (cited from above post):

I found another workaround, turning off sleep mode. Maybe there are
  easier ways to do it, but i did it like this:
(copied the instructions from another forum):

Download and install a free app Load Monitor.
Under its preferences check the following on...
Add Notification, Only notify high load, Auto start, and most importantly Wake Lock.

The wake lock prevents the phone from going into sleep mode, now i'm
  already 24 hours without shutdowns. I also set the update interval to
  2 hours for the Load monitor, so it doesn't bug me often.
The downside must be battery consumption, i assume that the sleep mode
  does save up some juice. But at the moment i'd rather worry for the
  battery than if the phone is on or not. :)
Also, this problem is not limited to galaxy ace.. A little searching
  with google revealed that there is even a class action lawsuit against
  Samsung because of the same problem in Samsung S models.

Hope it Help


Does the state forbid competition with so-called natural monopolies?

Question: (I don't need information about specific country, so it's OK to post information about laws of country that you know, just remember to include the name of the country in your post).
For example, I heard that the state forbids competition with public utilities. So you can't have two water pipes systems in your house, even if you're willing to pay big money for it. You can't open new water-pipes company, it would be against the law.
Is it correct? I just can't find anything that would either support or disprove such information.
If it's correct, then I would want you to provide me few examples of this.
Comment: So are you asking if in some jurisdiction, the government grants a statutory monopoly for something? Telecommunications in Saudi Arabia is one example, and there are a few zillion other examples.
Comment: Usually these rules are manifested in a general requirement that monopoly service providers of certain kinds get permission from a local government (a requirement contained in a local government ordinance) or a state public utility commission which establishes the requirement by regulation, and then the details are set out in an individually negotiated contract between the governmental entity and the provider. They are usually put up for bid every ten or twenty years. Boulder, Colorado, for example, just dumped theirs.
Answer:
You can't open new water-pipes company, it would be against the law. Is it correct?

In the US it depends on state law.
According to Wisconsin law:

(a) Except as provided in par. (am), the commission may not grant any person a license, permit or franchise to own, operate, manage or control any plant or equipment for the production, transmission, delivery or furnishing of heat, light, water or power in the municipality, if there is in operation under an indeterminate permit a public utility engaged in similar service in the municipality, unless the person seeking the license, permit or franchise secures from the commission a declaration, after a public hearing of any interested party, that public convenience and necessity require the delivery of service by the applicant.

So it's not technically prohibited to have a second utility under Wisconsin law; it's just that you have to show a very good reason.


What is the coolest way (using passive cooling only) to step 12V DC down to 5V DC

Question: I'm building a project that needs both 5V and 12V rails which will draw about 1A on the 12V and 0.5A on the 5V. I was thinking of using a 7805 to produce the required 5V but this could generate some significant heat. I am not so much asking if it is acceptable to use a 7805 (I just need a mini heatsink), but rather: are there any ways of doing it cooler? Any tips would be great.
Answer: Instead of using a linear regulator, which has relatively low efficiency (~50%), use a switching DC-DC converter (efficiency around 80-90%). A decent one to start with is National's "simple switcher." It looks like the LMZ12001 would do the job-- up to 1 A at 5 V, and it accepts input voltages from 0.8-20 V.
http://www.national.com/pf/LM/LMZ12001.html
Comment: switcher circuit design can be difficult, if your not careful with controlling the switching current loops you can induce noise throughout your design not to mention generate large about of EMI.  Also keep in mind that the output of the switcher will have a much higher ripple voltage than the output of LDOs.  If you have anything noise sensitive you will need to plan for at least an LC filter on the output.
Comment: The cheapest switchers I know of are the old (but still in production) MC34063. Just be sure to use use very fast diodes (preferably Schottky).
Comment: Yeah, the National simple switchers aren't cheap, but they're pretty hard to screw up. The reason that they're expensive is that they have some of the passives integrated into the chip package. I think it's a worthwhile tradeoff if you're just trying to get something working. They'd be a bad choice in a production design.
Comment: @jpc - definitely Schottky! Not only because of their speed, but also because of the lower voltage drop. Even more relevant for lower \$V_{OUT}\$.
Answer: One of the main issues with regulators like the LM7805 (and linear regulators in general) when you step down from large voltages is that a lot of the energy is dissipated as heat. If you are limited to passive cooling only and you have some significant power draw from your load, you might risk thermal overload.
Fear not, because if you are willing to put up with a bit more complexity and cost there is another option: Switching regulators, specifically in this case buck converters, which work off of a completely different principle. Depending on what your other requirements are, like noise, stability, EMI considerations, you might look into some of the highly integrated switching regulator modules offered by TI, like the PTN78000W family. That part in particular is nice because of the adjustable output, so you can produce a variety of supply rails off of one part.
Cheers!
Answer: Switching regulators (aka DC/DC converters) can step down 12V to 5V step without generating too much heat. Since you only need 2.5W on your 5V, don't think you need a heatsink too.
Lineage has some good DC/DC regulators: http://www.lineagepower.com/category.aspx?NID=5e1812f4-fb02-49f4-ba31-6e312010f40d
I'm assuming here that you need a non-isolated converter ie. your 5V does not need be electrically isolated with a transformer from the 12V. Non-isolated dc/dc are cheaper and smaller.


Search for a string in all of the files in git's staging area and all those files changed but not staged

Question: I am trying to search for a string (e.g. search for string "TODO") in all of my files which are changed locally. That includes files which were already staged and those that are changed but are not added to staging area yet.
Comment: Yeah but git grep will also search files that are unchanged in the current working directory.
Comment: Pipe the results of a git status into grep using a for loop?
Comment: `git grep TODO`?  (Note that this starts in working directory, add `-- :/` to start at top of repository.)  This looks at unmodified files too though.
Comment: Readers will probably get the most benefit from answers using the commands built into git. After all, git aims directly at helping you manage 'plaintext' changes in a repo....
Answer: Answering my own question. I was able to do it with the following command
git diff --name-only | xargs grep 'My search string goes here'

Comment: That doesn't find staged changes, right? For staged and unstaged changes you want `git diff HEAD`
Comment: This shows the files which are changed and search strings in that files, but what about to search only changes, added, removed strings. ?
Comment: `git diff-index --cached -S{STRINGTOSEARCH} -u HEAD` it requires at least the file added to git via `git add path/to`
Answer: The correct answer would be
git diff-index -S{STRINGTOSEARCH} -u HEAD
newly added files have to be added to staging through
git add path/to/filename
searches the intented string in only added/removed strings.
Comment: kudos for the answer that uses the tool 'as designed' vs introducing outside, cobbled-together approaches
Answer: I found the -S{STRING} version rather hard to use since regex are not straight forward. An easier version for me is to pipe the output into grep and use it's pattern matching:
git diff-index --cached -u HEAD | grep -i string

Or for multiple strings at the same time:
git diff-index --cached -u HEAD | grep -i -e string1 -e string2 -e string3

-i is for case insensitivity and -e is to add more patterns.
You can add this as an alias to your rc and check for your personal details for every commit if you want.
Comment: Being able to search multiple strings is helpful. Thanks!
Answer: Here is a bash snippet that works on Debian to accomplish this:
for file in `git status -s -uno`
        do
                if [[ ! $file =~ [A-Z] ]]; then
                        echo "$file"
                        grep -n "TODO" $file
                fi
        done

Explanation:
git status -s -uno is short form of git status but excludes untracked files.
The if condition in the for loop skips over the status part of git status -s to avoid searching through files that don't exist.
Finally the -n option ot grep prints the line numbers. Simply change TODO to whatever you want to find.
I imagine it ought to work on git-bash in windows too...


Installing Ubuntu 17.04 to an external drive

Question: I am pretty new to this and I am trying to boot Ubuntu from a 1Tb extra hard drive. I have the iso installed already but not sure where to go from there. I've read about burning it to the external drive, which isn't working out out for me. I've also seen some posts about partitioning but I'm not sure what that means.
Comment: @sudodus My explanation is that I do not dislike either this question or your answer to it. In fact, now that you mention it, I may flag the question to be merged if it is closed as a duplicate in order to preserve your answer to it. I did not vote on anything that is posted on this page, merely voted that the question was a duplicate question. The eccentricities of user voting on this question are as baffling!?!? to me as they are to you.
Comment: @RahulDhruve, please edit the question and explain what you have and want to achieve: What operating system is installed in the internal drive? How do you want to use Ubuntu (test or use regularly; use in one single computer or as a portable drive in different computers)?
Comment: @karel et. al., Please explain why you do not like this question and my answer. (I am willing to modify or remove my answer, if you think that it causes confusion.)
Comment: @sudodus In addition please allow me to share my humble experience with eccentric voting patterns. My design work on another Stack Exchange site gets downvoted "irrationally" imo compared to here makes me ask myself if eccentric voting is somehow motivated by subjective or opinion-based considerations.
Answer: Do you want a regular installed Ubuntu system in this target '1Tb extra' hard drive? Or do you want a persistent live system? Both are possible. See this link and links from it,
Try Ubuntu (Kubuntu, Lubuntu, Xubuntu, ...) before installing it

Backup whatever data are stored in the 1Tb extra hard drive to another drive or to the 'internet cloud'.
Installed system (more stable, fairly portable)

Create a USB boot pendrive with a cloning tool, for example

the Ubuntu Startup Disk Creator (in Ubuntu 16.04 LTS and newer versions) or
mkusb or
Win32 Disk Imager or Rufus in Windows.

Boot from the USB boot pendrive drive and install Ubuntu to the target 1Tb extra hard drive.
It will be easier and safer if you remove the internal drive before installing to the 1Tb extra hard drive. Otherwise, in UEFI mode, the bootloader will be installed into the internal drive. If it is impossible to remove the internal drive in this target computer, you can create the USB boot drive in another computer. Avoid proprietary drivers! Move the drive to the target computer, and if necessary, install proprieatry drivers (typically for graphics and wifi).

Persistent live system (more portable, fairly stable)

Install mkusb and use it to create a persistent live system in the 1Tb extra hard drive. You can install mkusb in an existing installed Ubuntu system or in a live system (in a USB boot pendrive).


Rails 3 Plugin - Active Record table_name_prefix

Question: Im having problem to use table_name_prefix on my projects. I have a main apllication in my project that have others applications as plugins, these plugins works like a subsystem from the main application.
To organize the tables on database of the subsystems I would like to use the table_name_prefix of the ActiveRecord Plugin.
If I put on init.rb of plugin the command config.active_record.table_name_prefix = "per_" the main application will not work because the ActiveRecord will try to find for "per_users" but the only thing I want is that only the Plugin on my main application use the prefix "per_".
I tried to create a rails folder at my plugin with the command above but the same problem occurs, all the application try to find for prefixed table name.
An alternative is use the set_table_name in the model of plugin, but its not good for me because Im developing subsystems as rails plugin and I dont want to change the models when put the subsystem at the main application.
Someone can help me?
Comment: What version of rails are you using?
Answer: To have each plugin with own prefix, for Rails 3, try organize Your models inside plugin in namespace:
class Foo::Bar < ActiveRecord::Base
 ...
end

module Foo
  def self.table_name_prefix
    'foo_'
  end
end

This will works just inside the plugin without changing anything inside the main application.
Other approach is to use some main model and inherit it from others like that:
class Foo < ActiveRecord::Base
  def self.table_name_prefix
    'foo_'
  end
end

class Bar < Foo
 ...
end

sometimes this approach is used to extend all models with extra features.
More information in Rails documentation here
Answer: Take a look at this question. I ran into the same problem, forgot my application's name (main module) had the same name as a namespace for my models.


Question about the design contract work. / undecisive client

Question: I have a question about dealing with a client. They're not accepting the final design, and we've spent a lot of time making small changes to one part of the page, well beyond our estimated timeframe. The client keeps changing their mind in every meeting and can't provide clear preferences. All they say is 'I don't like it' and ask for more options, even after multiple revisions. This is my first design contract, and I'm not sure what's standard practice in the industry. What should I do?
Comment: It sounds like the client is fully ready to do the project. Constantly changing their minds means that they don't have a clear idea of what the problem is that they are trying to solve. One idea might be to say, "I'll come back in six months."
Comment: Is the contract fixed-price or hourly rate?
Comment: @morsor fixed as it's my first contract and wanted to be competitive - probably not the best choice in hindsight. Maybe I'll incorporate an hourly rate if the estimate is exceeded in the next work I do.
Comment: That should read "the client _isn't_ fully ready to do the project."
Answer: Stop the work immediately and demand payment. Justify this by listing the initial offer and the history of the changes.
There is a risk that the client will refuse to pay, but another risk that you do more work for free.
Keep in mind that an hour performed is an hour due.
Comment: Thanks, really appreciate the answer. I sent an email to the client to follow up on the initial deposit I haven't yet received
Answer: In my experience, no piece, even the most intricate complicated piece, has ever gone above 5-10 revisions. If a piece is surpassing that amount, or the requested revisions are "sweeping" in nature, something needs to be discussed.

If changes are repeatedly sweeping in nature, I'll stop working and have a conversation in order to determine why work thus far has been unsatisfactory. If the client isn't liking anything I'm creating, then they simply don't like my work and would be better served finding another designer they do like. I request payment for my time and move on. "I just don't like it" is not a response I'll accept. I push so I know why it's not liked. If a client is unnecessarily concerned with my "emotional well-being" over their reaction, then I'm not getting valuable, usable, responses from them. I often need to let the client know that my "ego" is not part of the equation... they can outright hate the work, and that's fine. But I need to know an honest response if they wish me to improve what they are seeing. If they aren't willing to provide more concise design direction, then it is indeed a "lost project" and I need to move on. The client is either unprepared for design or too indecisive for me to waste my time with.

If changes are more of the minor, typographical nature then the client is merely disorganized and I need to have a conversation about my time and how repeated minor changes are more costly. Essentially, I alert the client that I'm reaching a threshold of tolerable changes. I don't refuse to make any further changes. I merely make it known that my time is valuable and they need to be more decisive and targeted with any change requests. Thus far, this has always sufficed.

All the above being posted. If you have a contract, what does that state about revisions, if anything?
If you don't have a contract, then, well, it's a matter of negotiation, or just abandoning the project, hope you get paid and let the client find a designer they like.
Not every designer is suited for every project and every client. It can be considerably more beneficial in terms of my time to just let some clients or projects go to some other designer. I need to spend my time where it's most valuable to me, not the client.
Comment: Very good perspective, thanks for the elaborate answer. I'll pause the work for now and try to dig deeper into the  "I push so I know why it's not liked. " - although I tried that before and the client still wasn't very clear.
Answer: I'm noticing from the one of the comments here that you haven't received your initial deposit yet.  Oh my gosh!  You are being played.
As you have not received a penny of "consideration" for the current contract that required a deposit, many jurisdictions would consider your obligations under the contract as void due to breach.  (I am not an attorney)
Don't turn over any completed work product whatsoever.  The client is trying to get you to submit work on a speculative basis, and then when you submit something that approximates their needs, all of a sudden all of your calls to them will start going to voice mail and your emails will go unanswered.
This isn't about the client being indecisive.  This is more so about you being unwilling to set boundaries, and the client gradually testing and testing to see if you're going to draw the line -- and it looks as if you haven't.  When you have an undecisive client, you CANNOT accept fix priced work.  If the client controls the requirements and can change them at-will, you must charge hourly instead.  If the requirements are fixed, THEN and ONLY then you can charge a fixed price.
You're going to have to reel it in, or clients like this will eat you alive.  See the no-spec website.  Make sure you have specific payment terms in the contract (I wouldn't go past net 10).  In fact, for THIS slimy client it'd actually be better for you to take a retainer up front, and bill your hours out of the retainer until it's gone; at this point, the client must refill your retainer for work to continue.  This would be the safest situation for you.
I'd bet any kind of money that when you set some boundaries, this client will disappear.  But hey, you've gained some experience and no money -- call it "tuition".


Sending message to all players in room from Photon server?

Question: I need to send a message to all players in the room from a Photon server. Sending the message from a player would introduce too much latency so I need the server to collect data and distribute messages at a rate of 16/s without a player's influence. Is there a way to do this?
Answer: if (PhotonNetwork.isMasterClient)
    photonView.RPC ("SendMessageRPC", PhotonTargets.All, "Hello there!");

[PunRPC]
void SendMessage (string message) {
    chatBox.AddMessage (message);
}

The above is basically how to send a message, with you needing to impliment a GUI or UI for a chatBox and a script that has a public void function that is called AddMessage, which adds the string message onto the big string of all the messages.
I'm not sure if there is a way to guarantee the speed of delivery, as all the client's (and if you're using a server, also that) devices and network speed is not the same.
Comment: I need to initiate the message from the server. Calling it from the client would mean 1 extra trip for the message.
Comment: @JPtheK9 Sorry then, I'm not very sure how you do this :)
Comment: actually allot of games use client based applications to send "Master" or "Admin" messages this way. Arma 3 for example has RCON software to allow admins of servers to send global messages to all player from a client side application. I would recommend maybe making a admin tool for your game/application.