Extent of reaction vs driving force

Question: For an endothermic reaction with a negative change in entropy, based on dG = dH - TdS increasing the temperature should make the process "less spontaneous". However, if the reaction is endothermic then classic Le Chatelier principle says that the reaction should shift right with increasing temperature. How can we reconcile this?
Comment: Are you familiar with the Van't Hopf Equation and with its derivation?
Comment: Hi Chester, yes I am. How does this help?
Comment: The derivation explains the correct way to take into account the effect of temperature on the equilibrium constant.  The predictions from Van't Hopf are consistent with Le Chatelier.  Let's see your analysis using Van't Hopf.
Comment: dGo = dHo – TdSo = -RT lnK

Rearranging the second half of the equation gives (–dHo/RT)  +  (dSo/R)  =  lnK

So we have a linear relationship for lnK vs 1/T, with slope –dHo/R
Comment: So, from this equation, what is the sign of the derivative of lnK with respect to temperature if the reaction is exothermic?
Comment: Hi Chester, sorry for the delay, I was away. For an exothermic reaction we have a positive slope, so the equilibrium constant would decrease as temperature increases. This all makes sense, but what I am struggling with is how to reconcile this with the basic Gibbs equation.
Comment: dGo = dHo - T dSo. For an endothermic reaction with negative change in entropy, as T increases dGo also increases, making the process "less spontaneous". But from van't Hoff, for an endothermic reaction as T increases K increases, which means dGo decreases. There's a connection I'm missing here.
Answer: The change in free energy $\Delta G^0$ in these equations represents the change from molar quantities of reactants (in separate containers) at temperature T and pressure 1 bar, and corresponding molar quantities of products (in separate containers) at temperature T and pressure 1 bar.  So writing the equation in terms of differentials makes no sense.  It should more properly represented by $$\Delta G^0=H^0_{P}-H^0_R-T(S^0_P-S^0_R)$$where the subscript P represents products and the subscript R represents reactants.  So, $$\frac{\Delta G^0}{T}=\frac{H^0_{P}-H^0_R}{T}-(S^0_P-S^0_R)$$Now, for $H^0_P$ and $H^0_R$, since the pressure is constant between the two states of the products and reactants, respectively, at different temperatures, we have $$dH^0_P=(C_p)_PdT=TdS^0_P$$and $$dH^0_R=(C_p)_RdT=TdS^0_R$$So, algebraically, by the product rule for differentiation, we have$$\frac{d(\Delta G^0/T)}{dT}=-\frac{(H_P^0-H_R^0)}{T^2}+\frac{T(dS_P^0-dS_R^0)}{TdT}-\frac{(dS^0_P-dS^0_R)}{dT}=-\frac{(H_P^0-H_R^0)}{T^2}$$This is what you get when you do the math correctly.
Comment: My differentiation is a little rusty so I didn't follow the very last step, but essentially entropy out of the temperature dependence, correct?
Comment: Also, just to clarify, when I wrote dGo = dHo - T dSo I was not referring to differential quantities, rather d for delta.
Comment: That d and delta representation certainly confused me.  With regard to your previous comment, the differential of uv is udv+vdu.  What this leads to is that one of the terms from differentiating the enthalpy term with respect to temperature cancels with the temperature derivative of the entropy term.
Comment: So if we go back to the earlier discussion, because (delta)H does indeed depend on Temp (which we typically ignore), is it too simplistic to simply say that for an endothermic reaction with negative entropy change, increasing the temperature makes the reaction "less spontaneous" because we cannot simply plug into (delta)G = (delta)H - T (delta)S?
Comment: Yes.  The enthalpy dependence with temperature cancels with the entropy dependence with temperature.

Extent of reaction vs driving force


Could not find kernel image /isolinux/isolinux.cfg

Question: I have been trying to install Ubuntu 16.0.4 using the Universal USB Installer method for the past 3 hours. I looked up tutorials and searched for answers here but none worked. Any hints?
Selected sections of Universal USB Installer log
Create folder: E:\uui
Copy to E:\uui\syslinux.cfg
Executing syslinux on E:
Execute: C:\Users\pbgnz\AppData\Local\Temp\nsvB692.tmp\syslinux.exe -maf -d
/u...
Syslinux Errors 0
Creating Label UUI on E:
'LABEL' is not recognized as an internal or external command,
operable program or batch file.
Extracting the iso: The progress bar will not move until finished. Please be patient...

Then a couple of files are extracted and copied to the usb and the installation is complete. I renamed the files from isolinux to syslinux as shown in other tutorials.
some answers I tried:

Install Ubuntu 14.04 from bootable USB: Could not find kernel image: /isolinux/isolinux.cfg
kernel image error while installing Ubuntu 13.10
Comment: Does this answer your question? [How do I burn the Ubuntu ISO to a CD?](https://askubuntu.com/questions/203601/how-do-i-burn-the-ubuntu-iso-to-a-cd)
Answer: I successfully installed Ubuntu on my laptop. I had to "by pass" this issue by burning ubuntu on a dvd. You can probably find tutorials on that.


communication of two remote shell scripts through file

Question: I really need help to understand the strange behavior of my shell scripts.
In fact, I have two scripts running on different nodes. the first script ssh a remote node and launch the second script. the second script computes a cost and send it to the first script. for that the second script ssh the node of the first script (asker node) and write the cost in a file that will be read by the first script (as shown bellow).
the problem is that when the value of cost is 0 the first script continues its execution normally, but if its value is different then 0 the first script remains suspended and doesn't execute the instructions after the ssh.
Does anyone have an explanation for that?
I can give more details about my code if needed.
Thank you in advance.
First script:
<code>....
ssh $remore_node "sh cost_computation.sh <parameters>"
cost=`cat $response_file`
if [ $cost -eq 0 ]
then
    ....
else
    ....
fi
</code>
Second script (cost_computation):
<code>....
computation of the cost
ssh $asker_node "echo $cost > $response_file"
</code>
Answer: Can you just do this?
First script:
<code>....
cost=$(ssh $remore_node "sh cost_computation.sh <parameters>")
if [ $cost -eq 0 ]
then
    ....
else
    ....
fi
</code>
Second script (cost_computation):
<code>....
computation of the cost
echo $cost
</code>
Comment: Tanks for your reply. Strangely your code behaves exactly as mine.


Which state's laws determine guidelines for voluntary termination of parental rights?

Question: A couple has a child out of wedlock. The father pays child support for several years, but the mother and child live in a different state from the father/where the birth occurred. The father wishes to terminate his parental rights in order to no longer pay child support. Which state's laws govern the termination of rights? Is it the one the child is a resident of, or where the child was born?
Comment: There may be a misunderstanding here: I believe that while you may or may not be able to "terminate your rights", there is usually no way to get out of paying child support. What makes you believe the two are linked?
Comment: Well for a real world example, the situation that spawned this question. THe father does not have to pay child support anymore because the child legally has one parent and is able to be adopted by a new father.
Comment: Yes, I think adoption is one (the only?) case where the biological father no longer owes child support. Thanks for pointing this out.
Answer: Generally, in non-emergency situations, the state with jurisdiction over parenting issues related to children including relinquishment and adoption is vested in the courts of the "home state" of the child.
A child's "home state" is defined by statute by a coordinated definitions set forth in parallel laws at the state (the Uniform Child Custody Jurisdiction And Enforcement Act in 49 states) and federal (the Parental Kidnapping Prevent Act) level. This definition of "home state" provides a fairly precise definition of something that approximately matches your intuition regarding the state where the child resides in most cases. There is also an international treaty with a similar home state definition.
The state where the child was born ceases to be relevant at the point at which that state ceases to be the child's "home state". But, once a state's courts take jurisdiction over parenting issues for a child, the barrier to divest that state of jurisdiction is higher than it would be if there was no prior litigation. So, the state establishing the child support decree would often be the "home state" in the fact pattern set forth in this question.
I will refrain from discussing the substantive law of voluntary relinquishment following an acknowledgment of paternity and payment of child support at length in this post as it is beyond the scope of what was asked. Suffice it to say that this is generally disfavored and is sometimes impossible. Also, the actions that could lead to involuntary termination of parental rights (even for mere non-support) also often have parallel felony criminal sanctions associated with them.
Comment: The relinquishment that sparked me asking this question has already happened. I was trying to determine which state would have handled the request in case it matters for the other questions I will be asking regarding child support from a stepfather.


Calculus of Binary Relations

Question: I was reading "Origins of the Calculus of Binary Relations" by Vaughan Pratt where he says "it consists of two components, a logical or static component and a relative or dynamic component" but it seems as if it should be possible to define the "static component" purely in terms of the "dynamic component". Is this the case?
Comment: Or, Gerhard, someone else can answer it. :-)
Comment: You can "project" things down to the two element Boolean algebra and pretend you have invented it from a given relational structure.  I imagine Pratt has chosen his perspective for some purpose in his exposition.  After you have gone through it all and have a clear argument for why it might be better (for his exposition) to define the logical component in terms of the relational component, you can email him about it, or post it here.
I am unlikely to read enough of it soon to support such a stance, so you will have to do it.  Gerhard "Busy With Other Digital Documents" Paseman, 2011.10.24
Answer:
That was an historical paper, and the distinction in question was first drawn by De Morgan and then Peirce under the rubric of logical vs. relative as modifiers of sum and product.  In my own papers introducing dynamic logic as a binary version of unary static logic, starting in 1976 (based on class notes from 1974), I used those terms merely as the ones that occurred to me, as I was not familiar with the history and so did not know about "logic" vs. "relative."  Had I been aware of that precedent, "dynamic logic" might these days be called "relative logic," except that its modal character (see 2 below) mitigates against that.
My "Origins" paper was for the annual evening LICS talk, for LICS'92.  (It nearly didn't happen as I'd just had a quintuple bypass six weeks earlier.  Fortunately I'd recovered by then, and was able two weeks later to visit St. Petersburg, Moscow, Tver to give a conference talk, and Paris.)  An earlier paper,
Pratt, V.R., ``Dynamic algebras as a well-behaved fragment of relation
algebras'', Proc. Algebra and Computer Science, ed.  Bergman, Maddux,
and Pigozzi, LNCS 425, 77-110, Springer-Verlag, 1990.  Also Report No.
STAN-CS-90-1309, CS Dept., Stanford, 1990,
which was originally given as a talk at the workshop "Algebraic Logic and Universal Algebra in Theoretical Computer Science" held in Ames, Iowa in 1988, made the point that the complexity of various logical problems is lower for modules (understood as two-object gadgets) than for monoids as one-object structures.  The underlying intuition was that by limiting the operations in the "dynamic" object (where the monoid lived) and moving the Boolean stuff to the "static object" (a sort of cul-de-sac from which there was no return), the complexity was greatly reduced over that of relation algebra where all the operations can interact, creating much harder problems.  Even without star, Tarski's RA is undecidable, whereas dynamic algebra is decidable even with star, in fact I was even able to show its equational theory was decidable in deterministic exponential time.
Nevertheless the monoid situation greatly interested me, and in 1990, in response to a request by Johan van Benthem to speak at JELIA'90, I came up with Action Logic for my talk there.  You can read about this under "Action Algebra" on Wikipedia, whose lead redes as follows:
In algebraic logic, an action algebra is an algebraic structure which is both a residuated semilattice and a Kleene algebra. It adds the star or reflexive transitive closure operation of the latter to the former, while adding the left and right residuation or implication operations of the former to the latter. Unlike dynamic logic and other modal logics of programs, for which programs and propositions form two distinct sorts, action algebra combines the two into a single sort. It can be thought of as a variant of intuitionistic logic with star and with a noncommutative conjunction whose identity need not be the top element. Unlike Kleene algebras, action algebras form a variety, which furthermore is finitely axiomatizable, the crucial axiom being a•(a → a)* ≤ a. Unlike models of the equational theory of Kleene algebras (the regular expression equations), the star operation of action algebras is reflexive transitive closure in every model of the equations.
What the lead doesn't say is that it remains an open question after 22 years as to whether Action Logic as an equational theory is decidable.  (The word problem of course would be undecidable, the monoid alone should be enough to kill decidablity.)  Some people who've solved long-standing open problems, in particular Istvan Nemeti and his colleagues, have been unable to crack this one even after all this time.  So if you like this area and have been looking for something easier than the Riemann Hypothesis to hone your problem-solving skills on, just remember that every famously solved problem had its first solver.  People thought Andrew Wiles was just another person beating his head against a brick wall until he proved Fermat's Last Theorem.  This one seems very unlikely to be anywhere near that hard, it should fall simply to a good insight taking 5-10 pages to explain.
Comment: Welcome to MathOverflow, Vaughan.
Answer: As I understand it, and in more modern-day terms, the question asks whether it is possible to define the operations $0, 1, \cap, \cup, \neg$ on $P(X^2)$ (operations belonging to the "static component") in terms of "dynamic" operations $\delta', \delta, \circ, \circ', (-)^{op})$ where $\circ$ is relational composition (as an operator on $P(X^2)$):
$$(R \circ S)(x, z) := \exists_y R(x, y) \wedge S(y, z);$$
$\circ'$ is De Morgan dual to $\circ$:
$$(R \circ' S)(x, z) := \forall_y R(x, y) \vee S(y, z);$$
$\delta \in P(X^2)$ is the diagonal subset (the identity for $\circ$), $\delta'$ is its complement (the identity for $\circ'$), and $(-)^{op}$ is the relational converse:
$$R^{op}(x, y) = R(y, x).$$
The answer is no. For example, take $X$ to be $\mathbb{R}$, and consider the relation $n$ where $n(x, y) \Leftrightarrow (x = -y)$. Let $n'$ be the complement of $n$. I claim that the set $A = \{0, 1, \delta, \delta', n, n'\}$ is closed under the dynamic operations. It's clear that each of these elements is a fixed point under relational converse. It's also easy to check that $n \circ n = \delta$, and that
$$n' \circ n = \delta' = n \circ n',$$
$$\delta' \circ n = n' = n \circ \delta',$$
$$n' \circ n' = 1 = n' \circ \delta' = \delta' \circ n' = \delta' \circ \delta',$$
$$1 \circ x = 1 = x \circ 1  \qquad x \in A, x \neq 0$$
$$0 \circ x = 0 = x \circ 0 \qquad x \in A$$
Since $A$ is closed under complementation and under $\circ$, it is also closed under $\circ'$. Thus $A$ is closed under all the dynamic operations. However, it is clearly not closed under intersection, since $n \cap \delta$ is the singleton $\{(0, 0)\}$.
Comment: Sorry way out of my depth here! but I was assuming 1 = delta, intersection = composition and negation is complement with respect to 1. So n restricted to 1 is {(0,0)}.
Comment: To be clear, I was reading off the second column of the first page of the .pdf document. Yes, $\delta$ is what Pratt denotes as $1'$, to be clearly distinguished from $1$, the top element of $P(X^2)$ (viz., $X^2$ as a subset of itself). The dynamic analogue of intersection (multiplication) is relational composition, which Peirce well understood to be exactly analogous to matrix multiplication. The relative or dynamic analogue of negation was declared to be relational converse (which is not particularly apt IMO). There is much more to be said when we move from binary relations on a (cont.)
Comment: (cont.) *fixed* set or "universe of discourse" $X$ to binary relations between sets, where the relations between the so-called "static" and "dynamic" can be made much tighter.

Calculus of Binary Relations


General proof of equivalence of two FSMs in finite time?

Question: Does a general proof exist for the equivalence of two (deterministic) finite state machines that always takes finite time? That is, given two FSMs, can you prove that given the same inputs they will always produce the same outputs without actually needing to execute the FSMs (which could be non-terminating?). If such a proof does exist, what is the time complexity?
Answer: There is a proof, though I don't know it. Look for Sipser's textbook on the subject, that's where I know of it from.
Scrounging my memory: basically, there is a unique minimal DFA for a given DFA, and there is a minimization algorithm that always terminates. Minimize both A and B, and see if they have the same minimal DFA. I don't know the complexity of the minimization, though its not too bad (I think its polynomial). Graph isomorphism is pretty hard to compute, but because there's a special starting node, it may hopefully be somewhat easier. You may not even require graph isomorphism, to be honest.
But no, you don't ever need to actually run the DFAs, just analyze their structure.
Comment: Graph isomorphism is not known to be NP-complete, and in fact, is believed not to be.
Comment: You're absolutely right, my mistake. I have edited the post to fix that.
Answer: Suppose you have two FSMs with O(n) states.  Then you can make an FSM of size O(n2) that recognizes only the symmetric difference of their accept languages. (Make an FSM that has states that correspond to a pair of states, one from each FSM.  Then on each step, update each part of the pair simultaneously.  A state in the new FSM is an accept state iff exactly one of the pair was an accept state.)  Now minimize this FSM and see if it is the same as the trivial one-state FSM that rejects everything.  Minimizing an FSM with m states takes time O(m log m), so overall you can do everything in time O(n2 log n).
@Agor correctly states that Sipser is a good reference for these sorts of things.  The key point of my answer is that you can do this in polynomial time, even with a small exponent.


Homepage URL showing a 404 error

Question: I migrated my website to this new domain. I removed the original homepage and re-labelled the current homepage as home.Now when I visit the homepage, it shows a 404 error although the page exist and also the front page is set as a static page and set to display the correct page.
Comment: Try visiting Settings > Permalinks (you don't have to change anything, just loading that page refreshes permalinks), then clear your browser cache completely or use an incognito window to check if that solved the problem. Right now www.changingliveswellness.ie/home/ resolves to a page - if that should actually be at www.changingliveswellness.ie it looks like WP is not recognizing that it's set to your static front page. I'd check Settings > Reading again and clear any site caches you may have.
Answer: Home, in your menu, should never point to a physical ( created by you ) page. Its meaning is simple - URL of your domain ( eg. http://example.com or https://example.com ).
Remove Home from your menu. Add Home to the menu as Custom Link, with URL = '/' and Navigation Label = 'Home'.
You're saying that your front page is a static page, created by you, with a content. Which means that in Settings -> Reading -> Front page displays you've selected A static page (select below), and in dropdown you've selected your existing page. Remove from the menu a link to that page. WordPress will know, based on your settings, what page to display, when a visitor clicks on Home.
If you intend to show all posts to your visitors, create a new page with title only ( eg. Posts, Blog ). Publish it. Select this page in dropdown of Settings -> Reading -> Front page displays -> Posts page. Add this page to your menu.
That's all. Now trash your Home page, created by you.
Comment: wtf are you talking about dude? Everyone's home page is crafted. At least it should be somehow.  This is the opposite of all thing.

Homepage URL showing a 404 error


Can I convert my Trek Marlin 7 frame to thru axle?

Question: I just got my trek marlin 7 bike and was wondering if I can convert it to TA( through axle).
Comment: In general you can't do this (at least not very well) because the slots where the axles go must be larger for a thru-axle bike.
Comment: If its not too late, can you return the bike as-new to the bike shop and choose the bike you wanted anyway ?
Answer: No, your frame is made for a quick release (QR). It cannot be converted to thru axle. That would require a new frame.
Answer: TLDR: rear, no, front, maybe. But the gain would be marginal, and is not worth the complication.
For the rear wheel, no, as the attachment system is part of the frame. But even if you could change it, the spacing for the wheel would still be 135mm (or 142mm TA axle length), while TA MTBs are using the Boost standard and have a 141mm spacing (so a 148mm axle length). To my knowledge, the offer in off-road wheels with 142mm axles are mostly gravel bike wheels. 142mm MTB seems to be a niche compared to 148mm or gravel.
For the front wheel, it's a bit different. You could technically change the fork and choose a fork with a through axle ...but: you need to check what kind of head tube the bike has: 1"1/8 (found on entry-level MTBs) or conical. I haven't seen forks with 1"1/8 head tubes and TA. Trek doesn't say which standard is used on the Marlin (which usually implies it's the one considered the "lowest"), so the answer is "probably not".
Comment: There's plenty of MTB 142TA hubs/wheels still being sold, which are labeled as "non-boost".
Comment: @MaplePanda I checked and corrected, but I wouldn't say "plenty": looking at bikester (popular EU online shop), there are 8 references for rear wheels with 142mm axles, and 137 for 148mm. And some of these 8 references are in fact modular hub that be adapted in 135mm QR or 142mm TA.


Term for an Unconsecrated Church

Question: Is there any special term for an unconsecrated or not-yet-consecrated church, chapel, cathedral, etc.?
Comment: I think "unconsecrated" is the best you'll get; a Church which was consecrated might become "deconsecrated" if profaned or destroyed.
Comment: Excellent question.  Haven't found the answer yet, but found these.  In the Catholic context, see [verb for the act of consecration](https://ell.stackexchange.com/questions/175219/the-act-of-declaring-and-revoking-a-structure-a-church) and the terminology for a building that is no longer used for church: [deconsecrated vs. desecrated](https://romanchurches.fandom.com/wiki/Deconsecrated_church).  Maybe "unconsecrated" is the answer !
Answer: Term for an Unconsecrated Church
I believe the term you are looking for is an oratory. Chapels within churches are normally not consecrated, but blessed, seeing that the entire church structure is already consecrated. Their altars are nevertheless consecrated. Chapels outside of churches are generally not consecrated but as in the case of hospitals and ships or wayside chapels and are considered oratories.
The term chapel is probably still in vogue here and there   and will also fit the bill. In my experience, an unconsecrated or yet-be-consecrated-church is generally referred to as a church. This would probably be the same for a cathedral that is yet to be consecrated: it would be called a cathedral notwithstanding.
Here is what the Catholic Encyclopedia has to say about oratories:

Oratory
(Latin oratorium, from orare, to pray)
As a general term, Oratory signifies a place of prayer, but technically it means a structure other than a parish church, set aside by ecclesiastical authority for prayer and the celebration of Mass. Oratories seem to have originated from the chapels erected over the tombs of the early martyrs where the faithful resorted to pray, and also from the necessity of having a place of cappella or capella. In this tent Mass was celebrated by the military chaplains (capellani). When at rest in the palace the relic likewise gave its name to the oratory where it was kept, and subsequently any oratory where Mass and Divine service were celebrated was called capella, chapelle, chapel. The word is first found used in this sense by Marculfus (seventh century), who gives the above etymology, an explanation which has been generally accepted ever since, though Durandus ventures upon an alternative derivation, to wit, capra, because the tent above mentioned was made of goat-skins. Another, but improbable, derivation is cupella, a domical or cup-shaped monument. The canopy over an altar was also at one time called a capella. In ecclesiastical documents the main sanctuary of a church is often termed the capella major, to distinguish it from the side-altars (cf. St. Charles Borromeo's "Instructions"). In Spain the sanctuary containing the high altar is to this day called the capilla mayor. The thing is, however, much more ancient than the name, and Thomassin quotes numerous early references to oratoria, sacella, and eukteria. In dealing with the subject a large number of different kinds of chapels are to be considered, which vary according to their connexion with, or dependence upon, other buildings, or to the specific uses to which they were put. Thus we have chapels which structurally form part of a larger church, those which are included within other buildings not churches, and those which are entirely separate and detached. We have also papal, royal, episcopal, votive, wayside and mortuary chapels. It seems best for the purposes of this article, first to trace the origin and development of chapels in general, and then to deal with the different kinds, according to their special uses, and under their respective titles, in alphabetical order.
Ecclesiastical law as to chapels
The present-day law of the Church, while placing no restriction on the erection of chapels that form part of a larger church, lays down very definite regulations respecting any that belong to the category of private chapels. This applies, however, only to those intended for the celebration of Mass; there is no restriction whatever as regards the setting apart of a particular chamber in a private house merely for purposes of private prayer and devotion. But for a chapel in which Mass is to be said, canon law legislates very strictly. Cardinals, bishops (even titular), and regular prelates, are allowed the use of a private chapel by right; for all others a special indult is required. The ordinary of the diocese can give the necessary permission for the chapel or oratory of an institution such as a religious house, an orphanage, hospital, workhouse, or prison, such chapels being usually public or semi-public. But for a strictly private chapel in a private house, intended only for the convenience of the inmates of the house, a papal indult must be obtained, and such indults are only granted for sufficient reasons, e.g. distance from a church, permanent ill-health of a member of the household, etc. With regard to the fulfilment of the obligation of hearing Mass in such private oratories, the ancient law of the Church was that the obligation could only be satisfied by attendance at the parish church. The Council of Trent somewhat modified this rule and since then theologians have differed as to what was the exact law. To settle the matter, Leo XIII, in 1899 (S. R. C. no. 4007), decided that;

the obligation can be satisfied by any one in all public or semi-public chapels to which the faithful have access; but

it cannot ordinarily be satisfied in a strictly private chapel by any persons other than those for whose convenience the chapel exists.

This rule, in practice, is capable of a somewhat wide interpretation, and the indult by which the permission for the chapel is granted usually extends the privilege to various other persons, e.g. relations, guests, servants, etc. All places of worship in England belonging to Catholics, like those of other religious bodies outside the Established Church, were formerly termed "chapels."
Comment: Here's a link to pictures http://www.fsspolgs.org/about/seminary/our-chapel-consecration/ and a document they had for the occasion http://www.fsspolgs.org/chapel_consecration.pdf  and the news release https://fssp.com/seminary-chapel-to-be-consecrated/
Comment: I don't think this is right. There are consecrated oratories (E.g the seminary chapel at the FSSP seminary in Nebraska) and churches may remain unconsecrated and only be blessed. The question specifically mentions also "yet to be consecrated" and an oratory doesn't become a church by being consecrated.
Comment: @eques Made a few changes. Could you please link me to the consecration of the FSSP seminary chapel?

Term for an Unconsecrated Church


What does it mean he that spared not his own son Romans 8:32

Question: He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?
Comment: John 3:16 "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life."
Answer: He references the Father. If the Father is willing to give up his son for us (by sacrifice on the cross), then he is willing to give everything to us. The verse highlights the love of the Father for us, lost children of the world. v38 is a fitting conclusion:

"For I am sure that neither death nor life, nor angels nor rulers, nor
  things present nor things to come, nor powers, nor height nor
  depth, nor anything else in all creation, will be able to separate us
  from the love of God in Christ Jesus our Lord."

Commentary from Precept Austin:

He who so freely gave the choicest thing that he had to give when we
  were yet helpless, ungodly, sinners and enemies of God (Ro 5:6, 8,
  10-see notes Romans 5:6; 5:8; 5:10) -- now that we are His friends --
  will He not complete the process (Php 1:6-note)?


Will Eclipse IDE 3.6.2 work just fine with OpenJDK Java 1.6?

Question: I have to turn my hand to a bit of Java/Tomcat and GNU C development. Will the current version of Eclipse (3.6.2 Helios) work just fine with the following configuration?:

OpenJDK Java 1.6.0
Centos 5.5 x32
Answer: Yes.  Eclipse recommends Java 1.5 or greater.
I haven't had any problems running Eclipse with OpenJDK.
Answer: I personally wasn't able to get eclipse working with the Open JDK and had to install the Sun JDK. I'm on Kubuntu 11.04.


Rock Band 3 and Ion Drum Rocker cymbals

Question: in Rock Band 3, when using the Ion Drum Rocker do the cymbals register as separate hits?  I heard in pro mode Rock Band 3 can do this.  But is the Ion Drum Rocker compatible?  Also is pro mode insanely difficult, or can you tame it down a bit for the more novice drummer?  :)
Answer: In Rock Band 3 Pro Drum mode, the cymbals show up differently on the tracks. They will show as circles instead of rectangles on the yellow, blue and green tracks. You must not only hit the correct color, but hit the drum or the cymbal as shown. Hitting the yellow drum pad when the yellow cymbal is shown counts as a miss.
You can adjust the difficulty just like in regular drums. There are Easy, Medium, Hard, and Expert versions of each song, as in regular drums.
The ION Drum rocker is compatible, but only comes with two cymbals. There can be a total of three used in the tracks (for yellow, blue and green). If you do not have all three cymbals, there is a setting in the game that allows you to enable only the cymbals you have. For example, if you have only two, you can set it to where only the yellow and green cymbals symbols will appear. The blue pad will then always show as a drum.
Comment: damn, beat me to it.   I have a Ion Drumset and love it.  The only thing I recommend is getting an Anti-stactic pad to put your drumset on.  I was having a lot of static discharge with my set (as I play on the carpet and the set is full metal).  The discharge would cause random hits mid song.
Comment: You can though buy the cymbal expansion pack, for the third cymbal, right?
Comment: As long as it is Ion Compatible, i dont see why not.
Comment: The cymbal expansions for the ION seem to be hard to find on Amazon. I don't know how rare they are now. It looks like the controller comes with one cymbal, not two like I thought.
Comment: Another alternative is to get an electronic drum kit and MIDI converter. I purchased a Yamaha DTX explorer kit, which comes with three cymbals. It's more money than the ION, but can be used as a drum set outside the game.
Comment: I'm pretty sure it comes with two.
Comment: Mine came with two cymbals

Rock Band 3 and Ion Drum Rocker cymbals


How can I make carving a chicken less messy?

Question: When I carve a roast chicken, a flood of juices overwhelms the moat on the carving board and inundates the counter. This is true whether or not I rest the meat before carving. Why? And how do I prevent it?
Comment: Get a baking tray to sit your carving board in? I use a small chopping board as a carving board because it sits easily in a tray with lots of volume for drip catching.
Comment: @Spagirl sounds like a good answer to me.  Post below!
Answer: As suggested in comments, you could try putting a small cutting/carving board into a large pan or baking tray to hold the liquid better.
In general, this is a good problem to have.  If you are carving a whole chicken, and no juices are coming out at all, you've probably overcooked it.  Resting will only help so much, as fully cooked chicken will generally be at a temperature when muscle fibers will have tightened and contracted, thereby squeezing out some moisture.  It's also possible that your chickens may have been injected with additional brine/broth (though this will generally be indicated on packaging).
As for how to prevent it, I might suggest less carving on the board and more cutting on individual plates.  I'm not sure how you cut up a roast chicken, but I generally start by only cutting off about six pieces -- the wings, the leg/thigh quarters at the thigh joint, and with a little practice you should be able to remove about 80%+ of the breast meat intact from each side in one large filet.  Depending on the size of your chicken, how many people you are planning to serve and what preferences they have, you can then go further and separate the legs from the thighs, and/or do a few cuts through the entire breast to make more white meat portions.  The fewer cuts you make on the carving board, the less juices will leak out there.  Instead, you can give more whole cuts (or parts of whole cuts) to people, who can cut them apart on their plates.  By that point, they meat will have rested and cooled more so it will release less juice, and any juice that is released will be flavor on their plates too, perhaps to be sopped up by other means.
Traditionally, I know many people tend to think of "carving a chicken" the same as "carving a turkey" and slicing thinly through the breast.  To me, that's a lot of work and often results in cold chicken by the time it is served.  It also will tend to release more juices during the slicing.  Even with a 20 lb. turkey, I tend to cut the entire breast off whole, then make thick slices down through the breast after it is detached and on the board.  It keeps the meat warmer, allows everyone to have a bit of skin if they want, and keeps everything moist.  Unless you or your guests are really attached to very thin slices of meat, I find it's better to leave things as whole as you can when you put them on people's plates.
Comment: With any carved meat, the resting period is often a key issue with retaining juice.  Even cooks that practice it diligently with roasts and even turkeys, can tend to skip it with smaller items like a roasted chicken in trying to get the meat served while still hot.  It is still an important step for quality, and just flat out mess.
Comment: @dlb - I don't disagree, but I'm not sure where I said otherwise. OP said the juices were flowing out "whether or not the meat was rested," so I offered advice beyond simply resting. Obviously resting is helpful. All I said was resting "can only do so much," which is true if you're cooking meat above rare, as generally the case with chicken. Above that, fibers will tighten and juice will be squeezed out. I never meant to imply resting wasn't the most obvious thing to do, but OP already seems to have tried it.
Answer: Even after resting a pool of liquid can still be sitting in the cavity of the chicken, when you cut this pool drains out onto your board. My solution is to stick a long spoon into the chicken the tip it up so the liquid drains out into the pan, this takes a maximum of 30 seconds. I then transfer it to the cutting board and carve.


Remapping TAB Key in BioShock Infinite?

Question: Is there a way to remap the TAB key? It won't do it through the in-game GUI because it says it's reserved, even though it does the same thing as the escape key. Is it possible to do it through editing a .ini file? I found where the key bindings are in the "Documents\My Games\BioShock Infinite\XGame\Config\XInput.ini" file, but I can't find the key binding for the "navigate to goal" key, which is default to "N". How would I change the binding from "N" to "TAB" through the .ini file?
Comment: Infinite was notorious for not allowing easy rebinds. I typically rebind the movement keys, and I remember when I first played it, it broke a ton of other functions. I had to use a controller just to switch ammo types, while still using m&k for movement and looking around.
Answer: No, I ran into the same issue as you did during my playthrough this weekend. The tab key is strangely tied down and cannot be rebound unless you install a third party key changing application.

Remapping TAB Key in BioShock Infinite?


Filter diagrams with atlas coverage layer in QGIS

Question: Please advise how I can hide diagrams outside of the coverage layer when using QGIS atlas function. I can do this for polygons,rasters etc without problem but whatever I do I cannot hide diagrams from other layers. Please see example below. Basically I do not want anything outside of the polygons..
Comment: You can use mask plugin.
Comment: plugin does not seem to work with QGIS 2.18 (no other options due to difficult administrators). This question not same as proposed duplicate because also covering diagrams which has  different settings. The answers to other question did not work when i tried
Comment: You can hide the labels with the mask, but I could not hide the diagrams. I do not think there is any solution at this time, sorry. I have some screenshots for hidding labels, but I cant upload it, the question is blocked.
Comment: thanks for your suggestions. I still cannot get any solution to work (including one marked as duplicate). I edited this question to make it diagram specific. If you can post a good answer either here or on the other question it would be most helpful. thx
Comment: Dissolve your poligons to one with specific field, and select that poligon, use mask plugin.
Answer: I found a solution, using a condition on the size of the diagram: if the entity is out of the coverage, I put the diagram size to zero:
<code>if( attribute($atlasfeature,  'atlas_field_name' ) = current_field_name  , siez_field_name , 0)
</code>


How to split the comma separated list in the stored procedure

Question: I am working on small module in which we pass the column name as comma-separated string to a stored procedure. In the stored procedure, we want to separate the column names out.
Comment: This is literally the definition of a "give me the code" post. There are dozens or thousands of a script like this all over the web. In the future, please share with us your research and concerns, rather than just blanket asking for the code.
Answer: The definitive article on the topic is Arrays and Lists in SQL Server 2005 and Beyond which contains code and performance test results for a variety of split functions.
You say these are column names? You should probably read another of Erland's articles on The Curse and Blessings of Dynamic SQL where he discusses both SQL injection and when dynamic SQL is a good idea.


Android Google translate update September 2017

Question: So the latest android update to Google now automatically translates a Web pages. It allows you to either never translate page or never translate language. Thing is, I'm learning the language so I want to translate the page only when I'm not sure if what is saying! Before I could choose to either ignore the translate pop up or use it. Now it translates the pages straight away, which in some cases screws them up so I can't use the menus, even after going back to the original language. Why fix something that wasn't broken!
Answer: Each app update generally should improve functionality/add new features or fix bug. If youre a fan of Google Translate you would've noticed that the new feature was already available in the web version. Since they're implementing this feature now in android, its not totally with bugs like the one you encountered.
So my suggestion is that you disable the translate webpage option and activate "translate copied text" option which was available in prior update. When the need arises to translate, just copy and a poo up would should for you to translate. [This is however not as fluid as the webpage translation though ]
Hope I helped... Lemme know


Can't seem to get a JNDI JDBC resource working in Liferay

Question: No joy in the Liferay forum on this issue and the clock is ticking on this project.  This may be caused by my lack of knowledge of Spring.
I have a JNDI global resource defined in server.xml and a resource link in context.xml in my Tomcat 7 /conf folder. I KNOW the JNDI resource is being loaded because I see the validation query being run as the server starts up. So far so good.
I have a portlet that just provides services to other portlets. In that portlet I have a hibernate.cfg.xml which has a session-factory that also points to the JDBC resource (don't know if this is needed or not). I also have an ext-spring.xml file in the services portlet that has the following:
<bean id="liferayHibernateSessionFactory" class="com.liferay.portal.spring.hibernate.PortletHibernateConfiguration" >
<property name="dataSource" ref="MyJDBCResource" />
</bean>

<bean id="MyJDBCResource" class="org.springframework.jndi.JndiObjectFactoryBean" >
<property name="jndiName" value="java:comp/env/jdbc/MyJDBCResource" />
</bean>

Adding the above in ext-spring.xml fixed an issue with a bean error on that services portlet upon deployment. In that service builder built portlet, a services jar was created and I put that service jar in the Tomcat_Home/lib/ext folder so that I could use the services provided by the portlet in my portlet. So far so good. But, when I invoke the portlet method which calls the services provided by the other portlet with the JNDI references, I get a "user lacks privilege or object not found" error. It is definitely object not found. When the query is run I see absolutely NO activity on the JDBC connection specified by the JNDI resource entry and in drilling down on the connection properties I only see the HSQLDB driver in use. It should be using the MSSQL driver specified in my global resource JNDI entry as far as I understand it.
SO WHAT AM I DOING WRONG? Do I need to add some configuration entries in the portlet that invokes the services?
This seems so simple. In reading the many posts that give instructions on using JNDI/JDBC resources I seem to have followed them correctly. Is there some trick to using JNDI/JDBC resources in LR 6.1.1 and Tomcat 7 that I have missed?
Thanks (and really hoping for some answers!).
Answer: First, you could try rewrite JNDI resource reference like this:
<bean id="MyJDBCResource" class="org.springframework.jndi.JndiObjectFactoryBean" >
  <property name="jndiName" value="jdbc/MyJDBCResource" />
</bean>

also, you could try different approach on JNDI resource lookup in Spring:
<jee:jndi-lookup id="MyJDBCResource" jndi-name="jdbc/MyJDBCResource" expected-type="javax.sql.DataSource" />

Not sure about first approch, but second will definitively fail early in case no JNDI resource could be found.
Hope this helps.


Only list and libraries are viewable to to other users. The web parts are not visible to other viewers

Question: I have full control.  I have approved an published all items and none are checked out to me.  There are no pending actions for others to approve any content.  Other users can add web parts with the same approval.  I have deleted and re added the web parts with no change.  I am not in a personal view.  Any help would be appreciated.
Answer: You have to make sure the pages and sites are also published.
If you see a yellow bar under your navigation that says something like this: "Status: Checked in and viewable by authorized users.  "
This means that your site/page is not properly published. You have to click on the "Publish" tab as shown below:

After you click Publish, the yellow bar should disappear and the web page and content should be visible to all users.
Also, be sure that you are not using "Target Audience" to a specific group that will exclude main users. Check the "Target Audience" column by clicking "Edit Webpart" on any webpart that is hidden >> Advanced >> Target Audience.
Hope this helps.


Is there a definition or standard for the symbol $\pm$

Question: In college, I had been taught the famous formula $$x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}.$$ Here $\pm$ means that I choose either $+$ or $-$. But I have seen sometimes in physics that $\pm$ can mean some interval. If $x=5 \text{ m}\pm 0.05\text{ m}$ then $4.95\text{ m}\leq x\leq 5.05\text{ m}$. It looks like there are two different definitions for a symbol $\pm$. On the other hand, I have seen that physicist are not always as rigorous in maths as mathematicians. So, my question is that is there just one definition for the symbol $\pm$ and physicist uses non-standard definition or two (maybe more) different definitions?
Comment: I think you're right. It has two different meanings depending on the context. It can either mean "either plus or minus" in mathematics (which is a concise way to write that there are **two** possibilities), or "give or take" in physics (which yields a **range** of possibilities).
Comment: I also skimmed document given in the link http://en.wikipedia.org/wiki/ISO/IEC_80000 but I didn't find the definition.
Answer: There are simply two different meanings for this symbol.
In mathematics
It is generally used as shorthand, either to indicate the presence of two possible values:
$$x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}$$
or to condense two equations into one:
$$\sin(a\pm b) = \sin(a)\cos(b) \pm \cos(a)\sin(b)$$
Note that it is sometimes used in tandem with the flipped plus/minus sign, as in
$$\cos(a\pm b) = \cos (a) \cos (b) \mp \sin (a) \sin (b)$$
in which $\mp$ and $\pm$ should be interpreted as having different signs.
In experimental sciences
It is used to indicate precision of a measurement. The interpretation can be a bit fuzzy. For example, the expression $X = 10\pm 1.5$ might mean
$$8.5 \leq X \leq 11.5$$
or it might mean that a particular confidence interval (for example, the 95% confidence interval) for $X$ is $[8.5, 11.5]$.
Answer: There is no mathematical definition of the $\pm$ symbol. However, it is a possibility of writing two or more equations into one easily memorizable form.
1) In the formula above it is an abbreviation for the two solutions of a quadratic equation.
2) As you stated in physics it may also be used to define a symmetric interval.
3) In statistics it is also used to describe the distribution of a random variable:
$x = 4 \pm 2.5$
would tell the reader that $x$ is a random variable with mean 4 and standard deviation 2.5 . However, there is no implicit assumption that the variable is Gaussian distributed.
Answer: (assuming $b\neq0$)
In Mathematics  $x=a\pm b$ indicates a spectrum of two point-solutions to an equation,   $$\text{either}\quad x=a+b,\\\text{or}\quad x=a-b$$
that is,
$$x\in\{a+b,a-b\}$$

In Physics $x=a\pm b$ refers to a value somewhere in the interval between the two boundary points $$x\geq a-b\quad\text{and}\quad x\leq a+b$$
or
$$x\in[a-b,a+b]$$
Comment: @UnkleRhaukus You should change the $=$ (equals) to a $\in$ (is contained in). I've just done this for you (also, +1 for the pictures).
Comment: (-1) "either $x = a + b$ or $x = a - b$" is not the same as "$x = \{a + b, a - b\}$", and the same for the second example.
Answer: I would say that in math, we use $\pm$ in a way that means "plus or minus", hence the quadratic formula with this notation.
In Physics, it is more interpreted as "more or less", which brings the interval signification.
As long as the context is clear it should not be misleading to understand what one means
Answer: Another way $\pm$ is used is when there is an expression
with multiple terms that can be either positive of negative.
If both "$\pm$" and "$\mp$" are used,
it often means that all the terms with
"$\pm$" have the same sign
and all the with "$\mp$" have the opposite sign.
For example,
the expression "$a\pm b \mp c \pm d \mp e$"
would mean that $b$ and $d$ would have the same sign
(either "+" or "-"),
and $c$ and $e$ would have the opposite sign.


How to deal with (orphaned) WakeLocks?

Question: I guess most of you at least have heard about WakeLocks. Many of you will have experienced them already -- wether knowingly or not. Some may know how to deal with them in general -- but only few know how to deal with the "more complicated candidates".
For those who don't know, though above link leads to an explanation, a short summary: Apps may request a WAKE_LOCK to keep a device component from "sleeping", so they can perform a task even when the display is turned off. This is very useful in most cases (e.g. keeping the screen on while navigating, keeping WiFi active to stream music) -- but used in the wrong way, it causes your battery to be drained within short term (up to 25% per hour).
Most times it is easy to identify the source (usually a bad behaving app) -- I will show this in an answer below, as it might prove helpful to many users. But what to do if the app which requested the WakeLock exits without releasing it? The Android system will not take care of it. Sure, a reboot would solve the issue -- but it is not always an (desired) option.
So, from a users perspective (I'm not asking about development solutions, but how a user can handle things):
What can be done *by the user* to solve the issue and avoid further battery drain?
I prefer answers not involving root (so all users can benefit from it). However, "rooted solutions" are fully valid and welcome as well.
Comment: I was under the impression that this was only true if you created the wakelock the "wrong" way, by using `/sys/power/wake_lock`, but that if you did it the "right" way using PowerManager and PowerManager.WakeLock, the service would both hold the real wakelock and release it even if your process was killed...
Comment: According to the information I linked, that's obviously not the case. Somebody reports there having checked the kernel sources, and did not find any hint to that. Hint for developers: seems like "partial wakelocks" can be requested *timed*, so they'd expire automatically when the timer's up and the wakelock aquire was not refreshed. That must be the "safe way" you refer to.
Answer: How can I tell I'm affected?
This is probably the first question to those not familiar with this topic. With Gingerbread (Android 2.3) and above, you've got a service aboard helping you to figure out: battery statistics. Though manufacturers tend to place it at different points, it's mostly found in Settings → About the phone → Battery or similar, and shows a list of the apps having used most of your battery. On top of that is a small graph. Tap that, and it brings you to a screen similar to this one:

Screenshot of battery statistics on Android 2.3
I chose a screenshot from one of my devices which illustrates the issue. Looking at the lower two blue bars ("Aktiv" = Device was kept awake (active), "Bildschirm an" = "Screen on"), the right-most blue bar on "Aktiv" indicates a WakeLock: Device was kept busy despite the fact the screen was turned off. So by this we can be pretty sure we've got a WakeLock -- but we cannot tell who caused it.
If your device does not offer this screen (or the bars at the bottom: I just discovered e.g. the LG Optimus 4X running Android 4.0.3 has cut these bars off), you can find them e.g. using GSam Battery Monitor:

Similar information from GSam Battery Monitor -- here the mentioned "blue bars" are yellow/orange
What caused the WakeLock?
Unfortunately, this question cannot be answered using pre-installed apps (except for, maybe, some Custom ROMs). But there are tools available that can. The best known candidate for this is BetterBatteryStats, and shows us the cause in its partial wakelocks section:

Screenshots from BetterBatteryStats
In the first example2 (taken from the app's playstore page), the event causing most of the WakeLocks was a desired one: We don't want the playback stopped while listening to music. So the second example3 (taken from a real case on one of my devices) might prove better: the topmost 3 events are caused by the very same app, which needed the WakeLock to keep the IMAP push service active.
For an alternative to BetterBatteryStats, check out the Wakelock Detector app mentioned in UzumApps' answer -- which seems easier to handle especially for non-techies:

Wakelock Detector -- Click image to enlarge. (Source: Google Play)
What can be done?
If the case is as clear as in the second example in the previous section, the action is quite obvious -- at least in my case: I don't need to be informed immediately when a mail arrives; a delay of 30min is absolutely acceptable. So I went into the mail app, disabled IMAP Push (see also: Push Email), and instead switched to a 30min poll interval. WakeLocks did not entirely disappear, but dropped markably -- battery life improved noticably.
Then there's the case mentioned in the question itself: A bad behaving app not releasing its WakeLock. Confront the dev with your findings and ask for a fix. If he delivers: problem solved. If not: There's almost always an alternative app available.
What if it is the Android System itself?
Yeah, sometimes it looks like just that: 98% or more consumed by some Android service. Oh, if it's 98%, in most cases the candidate is named LocationManagerService. Bad guy spying at us? Not necessarily. In this special case, the listed "bad guy" is not even guilty -- at least not directly. Here it is another app requesting the current location too frequently. There's an excellent article on Setera.org about this: Pinpointing Android LocationManagerService battery drain. To give an abstract: It uses Android's dumpsys feature (requires root!) to dump a system state, and lets you investigate the listeners established for the LocationManagerService. A closer look at their configuration shows which are constantly "hammering" it for location info (some do so permanently, i.e. without a break). As the app's ID is listed along, and at another place in the dump even together with the apps technical name, you can still identify it and take appropriate actions.
And what about UFOs?
Unfortunately, there are such: Apps which registered a WakeLock -- and then exited without releasing it. What's left are *Unused F***ing Obsoletes* -- WakeLocks held for no use. So no way to simply bring the app to foreground and re-configure, or making it release its WakeLocks.
Here the only solution known to me is a reboot -- and I would like to have a better solution. Of course, if you know the guilty app, the steps concerning it are the same as above: inform the dev, get a fix -- or replace the app. But about getting rid of the current WakeLock? Maybe somebody else can provide a better alternative to the reboot?
Are there some recommended further readings?
Sure. One for now, I may add more later:

[GUIDE] Wakelocks Definition and how to prevent them (XDA Developers, March 2013)
Comment: Better education to developers to say... "Release wakelocks when you are done with them and clean up after yourself"?
Comment: Sure -- but see my question: I'm explicitly **NOT** asking about the developer side, but *from a users perspective*. Maybe I need to make that more obvious ;)
Comment: Please do! And report your findings! I just had that described issue with the "orphaned" WakeLocks. Poking around for an hour, I didn't get further than seeing it was the *LocationManagerService*. Registered for updates all 0sec (sic!) was the *Android Settings* (=:-0). I exited it, stopped it, killed it at the command line... no way to get rid of the locks. WTF did *Settings* do there? A reboot solved it, of course -- but is this a WindowsPhone we have to reboot twice a day?
Comment: If I have time this weekend, I will poke around under the hood to see if there's a mechanism to get the kernel to boot out orphaned wakelocks.... ;)
Answer: In short, this is a very good question but am afraid, it warrants more than just making the end-user aware!
Redesign the kernel to eliminate wake-locks and use a more thorough efficient way of managing the principle better thereby prolonging battery life.
Unfortunately, it has been accepted as a de-facto solution to enable "power management" despite it is not exactly efficient either! There was an extensive discussion about wakelocks (with Gregh Kroah Hartman - the Linux guru for drivers development - am googling for the exact linky), other sites such as LWN.net and another article explained on the same site here. This was the article Gregh Kroah Hartman referred to this blog, in which he appears to agree with the alternative solution proposed by Rafael J. Wysocki have documented a lot about the potential alternative. Am not sure if that is actually in place in the more modern kernel v3.x.x.
Badly designed apps can and often request wakelocks such as keeping the screen on, but in fact, in this scenario for keeping the screen on, there is in fact a more efficient way to do this:
getWindow().addFlags(LayoutParams.FLAG_KEEP_SCREEN_ON);

Whilst, striving to keep this clear of jargon etc for the end user, really the core of the issue boils down to the kernel code in how the wakelocks are managed.
Here is a brief summary on XDA on what is wakelocks for the uninitiated. By using BetterBatteryStats, one could see exactly which process is draining the battery, the wiki is hosted on github, and is available on the market here.
Comment: Funny you point to the same XDA thread I mentioned. I agree with you that the system should take better care (e.g. by releasing WakeLocks requested by apps which are no longer running). And that developers should take better care in coding (by explicitly releasing them at the appropriate states of the LifeCycle). But that doesn't help us users *know*. I hope my answer gives some insight in what a user can do -- and that one of you "techies" can fill the gap left!
Answer: Check out Wakelock Detector: XDA-Developers / Google Play:
Wakelock detector groups the wakelocks of app into one expandable view for better look. And it shows which apps are running. And there are kill uninstall info buttons in expanded view of app.

Click image to enlarge. (Source: Google Play)
Disclosure: I am one of responsible developer for this app. Four more friends are with me working on this project as a hobby.
Comment: Thank you! That's a valuable information indeed. Would you mind to add some more details to your answer, e.g. what makes it so special? I would add some screenshots then. Until that's done: Here's the [Playstore link to the app](https://play.google.com/store/apps/details?id=com.uzumapps.wakelockdetector)...
Comment: Thank you for the details! I merged them into your answer, I hope you don't mind :) Question of understanding: Say an app queries the location using an interval of "0 seconds". This would cause the *LocationService* to wakelock the device. Would *Wake Lock Detector* show the responsible app then as the real cause -- or the *LocationService*, as it's not a part of that apps package?
Comment: The answer for your question is 'no'  because wakelock detector groups wakelocks that belong to the same app packagename. As Location Service belongs to android os, the solution would be checking User permissions of app
Comment: Thanks a lot! I was hoping for an easy solution to the "What if it is the Android System itself?" part. Seems there isn't such a thing -- but if it's possible, it might be a good idea to integrate with WLD :)
Answer: A couple of ways that would help unrooted device users

Seeing that @Uzumapps, one of the developers of the app has posted a solution using Wakelock Detector (WLD), I am surprised that he has not updated about using the app which can also be used without root called Wakelock Detector Light ! I discovered this searching for a solution for my new device (unrooted).

This is a recent development and hence posting this for unrooted device users. Tested as working on Moto X Play (Android 6.0.1)

Download WLD from Play store link above
Manual for using WLD here
Instructions for  non rooted devices here. It has all the details but to summarise:

Enable USB debugging on device and adb
Download Wakelock Unlocker for Chrome on your laptop (also works on Chromium)
Enable it and you are done !
Wakelock Detector Light version does not display stats since Unplugged

There is another alternative on reddit which involves running command below in a loop as mentioned here

adb shell dumpsys power | grep -i partial_wake_lock

Note: I couldn't get the second method working, would welcome editing solution in making it work for non savvy guys like me

How to deal with (orphaned) WakeLocks?


why lithium is less reactive than sodium?

Question: Lithium lies above sodium in a group and is also smaller in size. According to periodic trend reactivity decreases from left to right in period and down the group.
Answer: Reactivity decreases down the group for halogens and increases down the group for alkali metals.
As you have said, Lithium is smaller than Sodium, the valence electron on sodium is further away from the positive nucleus and therefore it has a weaker electrostatic attraction and is more easily lost in a chemical reaction, making it more reactive. This is due to the shielding effect of the second energy level (electron shell) which makes the valence electron on Sodium further away from the nucleus and hence the larger atomic radii.


Raspberry Pi, how can i turn bluetooth on and off over Python script?

Question: i want to play either a sound, which is saved on my raspberry pi as a MP3 file or send a song from my phone over bluetooth to my Pi. So i found out, that if i run a song over bluetooth and play one from a saved MP3 file, the audio output gets disturbed and isn't able to handle both sources. My idea is, to only turn bluetooth on, if i am sure, that no sound is played from a saved MP3 file. My question: how can i turn on and off bluetooth over my Python script? I want to integrate these commands in my main programm. thanks
Comment: @Sanders the answer you have linked to is for Windows machines. For RPi the commands are different.
Comment: Is this what you're looking for:
 [Turning Bluetooth on and off using Python](https://stackoverflow.com/questions/66417181/turning-bluetooth-on-off-using-python-script)
Comment: @ukBaz Thank you for catching that.
Answer: The Bluetooth stack on Linux is BlueZ and they make a series of APIs available using D-Bus to interface with the Bluetooth hardware.
The documentation for the various API's is available at:
https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc
If you have not used D-Bus before it can be a little bit of a learning curve. There are libraries like pydbus that try to make it more Pythonic.
The command line tool busctl can be useful to experiment with how D-Bus works with BlueZ. For example busctl tree org.bluez will show a tree of the BlueZ objects. /org/bluez/hci0 is normally the built in Bluetooth adapter on a Raspberry Pi.
The API for the Bluetooth Adapter  has a Powered property that you can use to turn the power on and off.
An example of what a script might look like to toggle the power would be:
import pydbus

# DBus object paths
BLUEZ_SERVICE = 'org.bluez'
ADAPTER_PATH = '/org/bluez/hci0'

# setup dbus
bus = pydbus.SystemBus()
adapter = bus.get(BLUEZ_SERVICE, ADAPTER_PATH)

# toggle power of adapter
if adapter.Powered:
    adapter.Powered = False
else:
    adapter.Powered = True

In a separate terminal have bluetoothctl running and it will report if the script has successfully changed the power.


how to calculate matrix in excel 2016

Question: I have a spread sheet of (36x1) with matrix (1x15). I want to calculate a matrix value. I use Microsoft Excel 2016. My coding is =MMULT(A1:Z1 B5:19). The answer is you input too view arguments of this function. I think I have made a wrong calculation. But it clear I follow from the website or other person who can calculate the matrix.  Is there any one can help?
Answer: Select the output range. Input the formula:
=MMULT(A1:Z1;B5:19)

Then press the keys [Ctrl] + [Shift] + [Enter]
Answer: I follow your suggestion and the answer is enter image description here. I don't know why?
Answer: It seems that you enter the wrong format of MMULT() formula. The right format is "=MMULT(array1, array2)". Maybe you should input the formula:
=MMULT(A1:Z1,B5:B19)

Please refer to MMULT function and Create an array formula that calculates a multiple result.
Note that you need to select multiple cells and press [Ctrl] + [Shift] + [Enter]. For example:
Answer: I send you again my figure. It seems not to difficult to formulate MMULT, but it still doesn't work. Cam yout tell me how to calculate in manual mannner? enter image description here
Comment: In your formula, there should be a comma instead of a semicolon between the two parameters. If you want to get a multiple result, you need to select multiple cells and press {[Ctrl] + [Shift] + [Enter]}. Please refer to the links from my answer.

how to calculate matrix in excel 2016


added_date in users/{id}/favorites method result

Question: Is it possibile to include an "added_date" parameter on users/{id}/favorites method result?
It would be helpful when method is called with "added" sort parameter.
Answer: You'll notice that the same questions object is returned by all the various methods.
This is intentional, and I'm loath to make an exception in this case.
You can get the set of questions favorite'd within a date range via the min and max parameters however (provided sort=added).
Comment: Yep, i've noticed that.
I was adding the browse favorites questions feature on StackPrinter and i thought to show an "added date" detail to the user.
If it can't be done easily or it could mess your design, don't add an exception for this case :).


Atmospheric heating and the reduction in viscosity

Question: The oceans are becoming less viscous as they are heated. I'd imagine a similar effect is likely occurring in the atmosphere as well. What, if any, effect would this reduction of viscosity have on aeroplanes? Would they be more efficient and use less fuel?
Answer: As far as I remember viscosity of the gases, unlike liquids, increases with increasing temperature. So in order to decrease viscosity, You would have to cool the air (which is already cold at some 10 km).
When it comes to it's effect on planes, viscosity is responsible for creating pressure gradient between top and bottom side of an airfoil or wing. That pressure gradient creates lift. On the other hand viscosity affects drag - generally the more viscous fluid, the greater drag.
There is no easy answer to Your question, but if You would like to improve flight conditions, I think it would be easier to start with the plane construction and materials, instead of the air viscosity.
Comment: The viscosity of (an ideal) gas does indeed [increase with temperature](http://en.wikipedia.org/wiki/Viscosity#Effect_of_temperature_on_the_viscosity_of_a_gas).
Comment: It is not clear (to me at least) whether or not an increase in viscosity would increase drag. An increase in viscosity would decrease the Reynolds number causing the location of transition from laminar-to-turbulent flow to move towards the trailing edge.
Comment: First of all, there are different kinds of drag and "[the effect of viscosity](http://www.pilotfriend.com/training/flight_training/aero/drag.htm) is that the lift is reduced and a total drag composed of skin-friction drag and pressure drag is present. Both of these are detrimental effects. (...) No drag would result if the airflow were frictionless (inviscid). "
Comment: @Wojciech Not only would no drag exist if it were inviscid, but no lift would exist either (technically).
Comment: Thank you all for the interesting discussion. It was just something I was pondering over while I try to learn a bit more about fluid dynamics. That is interesting about the ideal gas becoming more viscous with increasing temperature. I'll look into it further.


Where is CZ gate in IBM Quantum circuit composer

Question: I am trying to build the Grover circuit using the IBM Quantum Composer circuit composer. The Grover example has a CZ gate. I can't find that gate in circuit composer.
Answer: There is no Controlled-Z in the circuit composer by default because this gate can be built from CNOT ($CX$) and Hadamard gate $H$. This is because we have the identity
$$ Z = HXH$$
This implies that $CZ$ can be constructed as:

Now, in the qiskit composer, there is a button + Add that allows you to add this gate operation as a pre-defined gate and you can named it as CZ gate.
Comment: This is very helpful, thank you. The only downside I see is that the icon for the gate I add does not show the connection to the other qubit, only a box on line for one qubit. The cz gate for the Grover example shows a connection to both qubits.I am not sure how they did that. Are you allowed to design your own icons?
Answer: Not sure how it was in 2021, currently (Oct 2022) the way to create a CZ gate in the IBM Quantum Composer is:

Add a Z gate
Edit it
Add control
You can change the control and target qubit from the menu.


Proving that exactly half the partitions of $n$ into powers of 2 have an even number of parts

Question: Could you help me how to prove that exactly half the partitions of $n$ into powers of 2 have an even number of parts, please?
Answer: Let's go with a generating function proof since you're into those!
Consider the product
$$P=\prod_{n=0}^\infty\sum_{j=0}^\infty x^{2^nj}.$$
The coefficient of $x^m$ in this product is the number of partitions of $m$ into powers of two. If we modify it slightly by writing
$$P=\prod_{n=0}^\infty\sum_{j=0}^\infty (-1)^jx^{2^nj},$$
then each partition is given the weight $\pm 1$ according to whether the number of its parts is odd or even. Now of course this product is simply
$$P=\prod_{n=1}^\infty(1+x^{2^n})^{-1},$$
which, by my solution to your other problem, is equal to $1-x$. Thus for $m=0$ and $m=1$, there are respectively $1$ more and $1$ less partitions of $m$ into an even number of parts as there are into an odd number of parts; for all other $m$, there are equally many.
Comment: I'm not understanding the application, for example, if we take $n=6$ and the partition $2,4$ then if we add together these two elements we have 6 but this isn't a power of two.
Comment: You're absolutely right, thank you. I actually had the correct solution at first, but then I wrote a bunch of nonsense instead. It works now!
Comment: I'm not sure this is a bijection. Take $n=7$ and the partition 1,2,4 then this isn't the image of a partition in two parts thru your application
Comment: Sorry for this. I shouldn't post when I'm so tired. Here's something you might like better (if only because it works ;)).
Answer: Let $S_e$ be the set of even partitions and $S_o$ the set of odd. Take any partition $s$ of $S_e$.
Let $2^r$ be the highest power of $2$ in $s$. If $s$ contains a single $2^r$ write $s = 2^r + p$ for remainder partition $p$ and define $s' = 2^{r-1} + 2^{r-1} + p$ noting that the resulting odd partition contains more than one of it's highest power of $2$, being $2^{r-1}$.
Similarly, if $s$ contains multiple $2^r$ then write $s' = 2^{r+1} + p$, noting that the resulting odd partition contains only one of it's highest power $2$, being $2^{r+1}$. This defines a bijection.


How can I tell if a video has a variable frame rate?

Question: How can I tell if a video has a variable frame rate?  I don't need to be able to do it programmatically, I just don't want to have to install some program that's hundreds of megabytes; for example, if I could do it with the VLC Media Player, that would be perfect.
Answer: FFmpeg has a vfrdet filter for this purpose.
ffmpeg -i in -vf vfrdet -an -f null -

In the log, you'll see a readout of the form,
[Parsed_vfrdet_0 @ 0000000003d8fec0] VFR:0.833333 (50/10) min: 23 max: 291)

A non-zero value for VFR indicates a vfr stream. The first value in brackets is the number of frames with a duration different than the expected duration implied by the detected frame rate of the stream. The 2nd value is number of frames having the expected duration. The VFR value is the ratio of the first number to the sum of both.
A couple of caveats: a very low or very high value indicates a few errant frames with non-standard duration, usually the first and/or last frame. These can be considered CFR for most purposes. A value around 0.50 indicates the stream has a frame rate and/or timebase for which the notional frame duration cannot be exactly expressed in the stream's timebase, so the app which generated the file, oscillated the duration e.g. if a stream has a fps of 6 and a timebase of 1/100, then the ideal timestamps would be 0, 16.667, 33.334, 50.000, 66.667, 83.333, 100.000 for the first second of video, but timestamps are integers, so the muxer may store 0, 16, 34, 50, 67, 83, 100. This could show up as a stream with VFR value of 0.5
Comment: Hello Gyan, can you provide an article or two that teaches details such as that time stamps are integers, and what a muxer is and putting it all together? I would like to read up in depth on this. When googling I just get a bunch of high level stuff and ends up not being the detail that I want. Thanks!
Answer: Just use ffprobe
ffprobe -v quiet -print_format json -show_streams input

And check for the avg_frame_rate parameter of the desired video stream. If the value of this parameter is a fraction like this
"avg_frame_rate": "1205285219/50270287"

with a denominator that is not 1 then the video file has a variable frame rate.
If the value is like this
"avg_frame_rate": "25/1"

be sure the stream has a constant frame rate.
Comment: a "real" rational frame-rate doesn't mean that the stream is a VFR stream ! adjacent PTS difference statistics must be compute to 'decide' if there is a real variation in frame display time.
Answer: One can use MediaInfo (5 MB, crossplatform, has a portable version on Windows, gratis) to tell if a video has a variable frame rate:


How to create an mp3 file that is shorter than 1 second?

Question: I have a music file that is shorter than one second and whenever I save it as mp3, there is always empty space to make it bigger. I'm assuming there's a minimum for mp3. I'm using Logic Pro X. Anyways, how can I do this?
Comment: What program are you using?
Comment: @Meaningful Username I'm using Logic pro X. It's me the Op.
Comment: If saving as a .wav works ok you could try using a separate MP3 encoder to then output an mp3, and see if that solves your issue.
Comment: If you are a programmer and know how to write/run programs, I wrote a Java program that cuts wav files of any specified length and save them as mp3. If you want, I can send it to you.
Answer: I have just done a few experiments using Audacity running under Linux.
I created an mp3 file of length one second, which saved as a file of size 17729 bytes which opens as a 1 second audio file. After cutting it in half (in Audacity) and saving (technically: exporting) it, I get a file of size 9370 bytes which opens as a 0.5 second audio file.
So, I believe that any problem you are having is due to the software you are using, an not due to some limitation of the mp3 file format.
Edit:
Further experiments with 0.25 seconds and 0.1 seconds produce ever smaller file sizes. There will be a minimum, due to the embedded mp3 tags in the file.
Comment: Theoretically, the shortest possible MP3 would consist of one "transient", using 192 samples of the uncompressed audio data. For CD quality (44,100 samples/sec) that would be about 4.4 milliseconds of audio. But the MP3 specification doesn't put many constraints on the encoding process so long as the result is a valid file. If an MP3 encoder pads the length of the file to the nearest second, or even the nearest minute, it would still comply with the standard.
Comment: @alephzero Thanks for that. So, if the OP want his file shorter than his software seems to allow, maybe his best bet is to edit it in something like Audacity (should be available for most operating systems, I think), and then save or export it again?
Comment: I've found that Audacity on Windows pads out MP3s a little ... interesting that it does not on Linux.
Comment: AFAIK Audacity uses third-party MP3 encoders, not code written by the Audacity developers themselves. Maybe you have different encoders on Windows and Linux.
Comment: @alephzero You are absolutely right about the third-party encoders (and I should have known that). I guess that explains any possible discrepancies between platforms.


Office 365, SharePoint, Azure Active Directory write-back

Question: Is there a way to update Azure Active Directory from within O365 Sharepoint?
I would like employees to have the ability to update basic information like phone number, etc.
Previously on-prem we could do this, but I am having difficulty finding information specific to O365 SharePoint and Azure Active Directory.
Answer: Have users use https://myaccount.microsoft.com for write-back. If you're synchronizing from Active Directory, then no as Azure AD will block most writable fields.
From SPO, there is no built-in mechanism to do this.


Can chords be played on the flute?

Question: I have been playing the flute for some time now, and wanted to expand my knowledge of it. To do so, I started learning more about the standard music notation. While doing so, I ran into a concept called chords. I learned all about chords, and desired to play them on my flute, but couldn't think of a way to accomplish this. Is there a way to play chords on the flute?
Comment: FWIW, you might consider the (frowned-upon) combination of flute pitch and voiced pitch -- check out early Jethro Tull albums, for example.  Drat -- ninja'd by @leftaround
Comment: @CarlWitthoft Jazz musician Rahsaan Roland Kirk also used the singing while playing technique extensively and to great effect. It's also used quite a bit in modern flute music, so I'm not sure who it is that's frowning upon this technique.
Answer: The flute, like most wind instruments, is considered to be monophonic (as opposed to a piano, which is polyphonic), meaning you can only play one note at a time (within reasonable ability).
However, there exist "extended techniques" on the flute that go beyond the standard teachings. In this case, "multiphonics" (which is an odd term, since "multi-" is Latin while "phone" is Greek) allow you to play dyads (i.e. 2-note combinations, otherwise known as intervals) and even chords (3+ notes), based on the properties of harmonics and overtones.
The trouble is, these are very difficult and only possible with a certain selection of notes (depending on the fingerings), and you're probably not going to get a very pleasing tone on them.
There are several resources on this topic you can try to use. I'm not skilled with multiphonics, but For the Contemporary Flutist's suggested technique is to imagine your tone being a vowel - higher tones shape your embouchure like an "e", while lower tones need you to form an "o" - and try to play with two vowels at once, one at the top of your mouth and one at the bottom. The Virtual Flute suggests possible fingering combinations for optimal multiphonics.
Answer: It should be added to the other answers that in order to create in your ear the impression of playing a chord, the notes which make up a chord don't necessarily have to be played at the same time. They can as well be played as a sequence, which is called a broken chord or arpeggio. Whether it sounds pleasant to accompany a song playing the broken chords on a flute, I don't know, but you can easily use this technique if you just want to hear what a chord sounds like.
Answer: If you have a reasonable singing voice then of course you can sing whilst playing a different part. With practice you can produce two part harmony and even two part counterpoint.
If you choose the singing pitch to coincide with the harmonic you want then this will resonate within the flute and make the harmonic easier to produce. Of course there is a limit to this last idea depending on the range of your voice.
Comment: It's important to note that the result of singing into a flute is very different from singing while another person is playing the flute part: because the air flow at the mouthpiece is nonlinear, you get strong [intermodulation](https://en.wikipedia.org/wiki/Heterodyne). The resulting effect is best known from Ian Anderson's "distorted flute" sound in solos as [on Locomotive Breath](https://youtu.be/eSUdlUmtg3Q?t=2m22s).
Answer: Just to add to @Bladewood's answer, practising harmonics will help. Start with "bugle calls" by fingering a low D, say, and trying to hit higher notes. These higher notes are the harmonics. You should be able to get 4 or 5 notes out of that single fingering with a little practice. THEN aim to hit the first two together, then the first three.
There are good reasons to practise harmonics other than trying to make chords. It helps to project your lower octave, and if you're clever with the harmonics, it can give you alternative fingerings for tricky passages, too (only for emergencies, though! There will be tuning issues to overcome). It also help lip flexibility.
Answer: To play familiar chords instead of unusual multiphonics, you can cheat.  Play a broken chord, either in a strongly reverberant space like a stairwell or a cathedral, or into a microphone that feeds an electronic reverb.
Answer: Yes and no.
You can expand a chord in time and play it note after note, in any order: appregio.
You can play it with two or more flutes, e.g. with friends or via recordings: voices, orchestra, dubbing.
The tempered scale used today deviates intentionally from multiples based on standing waves, like you have in a flute. It will be hard to match the required frequency ratios always, for all notes and chords.

Can chords be played on the flute?


Is there a way to get the icons that are used in Summoner's Rift minimap?

Question: I'm developing a webapp and it would be awesome if there's a way to find (or extract) the icons (i.e.: turrets, inhibitors, pings, champion circles, nexus, baron, etc.)
Comment: RIOT has set a precedent that you may use their assets and data so long as your application is available to all players and only monetizes through ads. You should be good.
Comment: Is it legal to take assets like this without permission? Especially if you are going to be publishing this webapp online for others.
Comment: It's just a draft to plan your tactics or strategies in-game (an online paint with extra tools, sequences or frames, etc.). I believe I mean that this webapp is for educational purposes.
Answer: Option 1:
All of the game assets are packed into RAF files that can be extracted using this tool:
http://forums.na.leagueoflegends.com/board/showthread.php?p=8597866#post8597866
They tend to be in this folder: C:\Riot Games\League of Legends\RADS\projects\lol_game_client\filearchives
There you will find a ton of folders (one for each patch). Content generally resides in the folder of the patch on which it came, or possibly even the patch you installed the game on. Just sort the folders by content size and start from the largest, you will eventually find the right RAF file.
Once you find the files they could be any number of formats. Hopefully they will be png and you will be good to go but some may be dds or something like that. A quick web search of the extension should point you in the direction of a tool that can open that type.
Option 2:
Google or Bing Images + Photoshop or GIMP and construct the images on your own.
Option 3:
Some sites like lolking or lolpro have a number of the assets already extracted or chopped up, you can always grab them from these sites.
Chances are a combination of the above will get you everything you need asset wise. If you need any game statistics RIOT has made them available through this API: https://developer.riotgames.com/


How should I troubleshoot a dishwasher that stops in the last minute of the cycle?

Question: I have an LG model # LDS5040ST dishwasher.  I found it displaying an nE error code the other day.  The code description on the LG site says it is thrown due to the vario motor locking.  Today I tore it down to look at the motor.  I found some trash and a chewed up toothpick in the sump by the motor impeller.  I cleaned it all up,  put it back together (because if  I have to order a new motor it won't get here until Mar. 5), and tried to run it.  I watched it run for the whole cycle.  It got to 001 left then it beeped and threw the nE error again.  But I heard the motor running.  What should my next steps in troubleshooting be?  Could it be a control panel issue?
Comment: Try taking the pump apart again and cleaning, check the drain hose and impeller intake.
Answer: What you might have is a loose wire in the front panel ; this appears to be a common problem with Vario Motor errors on the LG Washers.
Verify that the motor turns and does not have any rough spots or stiff spots, check your sump and impeller areas again to be sure - but you are likely looking at a loose wire in the front panel.
Apparently the cables get stuck on something in the door panel and lose their flexibility and get pulled loose or apart - or wiggle to an internal breakage (this happens when the door is opened and closed).
The other possibility could also be the main board.


How to use apa6 man and have justified paragraphs

Question: I want to be able to use the apa6.cls class man but paragraphs are flushed to the left, and I want it to be justified.
Answer: Journal submissions should be left untouched, since the publisher will most likely reformat things to suit their needs. apa6 does issue \raggedright as part of the document class.
You could update the justification by loading the ragged2e package and issuing a \justifying wherever you want to have justified paragraphs.

\documentclass[man]{apa6}% http://ctan.org/pkg/apa6
\usepackage{lipsum,ragged2e}% http://ctan.org/pkg/{lipsum,ragged2e}
\title{Long title}\shorttitle{Short title}
\author{An author}
\begin{document}
\maketitle
\lipsum[2]
\justifying% Revert from \raggedright to justified
\lipsum[2]
\end{document}


Retrieve image from Histogram data of Qiskit

Question: I am trying to understand the quantum image processing.
Please refer the link- https://qiskit.org/textbook/ch-applications/image-processing-frqi-neqr.html.
I am not able to understand how to process the histogram data(shown below) to form an image out of it.
I know a little bit of matlab by which I can generate a image after reading the textfile data, but I donot not how to preprocess the below data so that it can represent an image.
Answer: The rightmost two bits of each string correspond to a pixel (e.g. 010 and 110 both correspond to pixel 10). The frequency we measure the string with a leading 1 tells us the intensity of that pixel.
Here's some quick code that decodes the counts dictionary:
for pixel in range(4):
    # convert to pixel number to bit strings, i.e. (00, 01 etc.)
    bit_str = f"{pixel:02b}"

    # Count no. of times we measure pixel string with intensity
    # bit == 1, and intensity bit == 0 respectively (if the string
    # doesn't exist in the dict, we default to 0).
    n_ones = counts.get('1'+bit_str, 0)
    n_zeros = counts.get('0'+bit_str, 0)

    # then pixel intensity ~= fraction of 1s
    pixel_value = n_ones / (n_ones + n_zeros)

    print(f"Pixel {bit_str} has intensity ~= {pixel_value}")

Pixel 00 has intensity ~= 0.0
Pixel 01 has intensity ~= 0.0
Pixel 10 has intensity ~= 0.0
Pixel 11 has intensity ~= 0.0

You can could store the pixel_values in a 2D array and use matplotlib's imshow to turn this back into an image. I think the page could be improved to show this.


Sculpting Issue: Mesh disappears into another one

Question:
I was doing the Andrew Price tutorial (doughnut) and i am stuck in the sculpting phase. I was doing just fine but I think I messed up in the modifier section of the icing. For some reason, when I get to sculpting the icing (with the inflate brush), the icing just disappears into the donut. I donnt know what I did but I do know I tried undoing it (Ctrl+Z) and it did not work, just as Andrew Price said it would. The icing seems to disappear into the donut whenever im in SCULPTING. The dribbles peak out the donut but that is it, the rest of the icing is somehow gone. Any help is appreciated guys. Ill leave the link for the video here if its of any help. Thanks!
https://www.youtube.com/watch?v=6OTX3ZdYvEA
Comment: Please edit your post and add a specific title that describes your question clearly.
Answer: In Sculpt Mode click Sculpt (to the right of where Sculpt Mode is shown) and now > "Show All".
For some reason, Alt + H doesn't unhide properly between edit-mode and sculpt-mode for me. So if I hide vertices in edit-mode and switch back to sculpt mode, the connecting faces are gone. Going back to edit-mode, pressing Alt + H reveals the hidden vertices in edit-mode, but they are gone again when I switch back to sculpt-mode. Only in sculpt-mode I can Show All to un-hide those vertices again.


Receiving BFSK on Kenwood TS2000 transceiver

Question: I have a digital data signal with frequency in the 434-438 MHz band. The data is BFSK modulated with frequency deviation of 9.6 khz, baud rate of 1200 bps. The bandwidth is 25 Khz.
 Is there a way I can receive the above signal on Kenwood TS-2000. The maximum deviation of TS2000 on BFSK mode is 850 Hz. But can I receive the data by using the TS200 in FM mode ? Is the baud rate of 1200 bps supported by TS2000 ?
Answer: Ashish,  you should be able to receive this using FM.  I'm not sure what the BFSK mode of the TS-2000 is but the data should be visible in FM mode.  You will then have an audio square wave (or rounded if there is some bit shaping).
If you feed the audio into a computer soundcard, you should be able to record the data with something like Audacity and see the bits. That will give you confidence that you can demodulate it from there.
Comment: The square wave will _also_ be rounded off by the high-frequency response of the FM receiver.
Comment: @Chris: Will we able to receive the data if it is not encoded in ax.25 protocol but uses synchronous protocol with preamble and synchronization word ? Will we able to receive the data using ARCP software ?
Comment: I know nothing about Kenwood radios or the ARCP software. You would probably need to decode it yourself by feeding the audio into a soundcard.  If it's a standard protocol then MixW or something like that may decode it.  If its something as part of a research project, then you will need to write the decoder.  We would need some more context to help further.
Comment: @Chris: Thanks for replying and apologies for late reply. The data is encoded using a custom protocol consisting of preamble and sync words and no flags which are used in ax.25 packets. In this, would it be possible to decode the data from the sound-card. How can we proceed with writing the decoder ? Will the TS-2000 forward the data to soundcard if no flags are used in the data packet ?
Answer: Kevin Reid has the most important point--   +/-9.6 kHz is beyond the +/- 7.5 kHz bandwidth of the TS-2000 receive filters. Without first modifying the hardware (replacing filter), I would expect the receive signal to be distorted, quite possibly beyond use.
Answer: This may be obvious. Signalink from Tigertronix is the sound card of choice for the digital radio of which I'm aware. Also the program soundmodem which does not support BFSK may be a starting place for building a decoder if the author is willing to be supportive.
KK4MG
Comment: That doesn't help if it's 25k wide.