What are the potential hazards of converting to a saltwater pool?

Question: We are thinking of converting our pool from chlorine to saltwater, but we've heard and read some things about possible issues with the lining or other things breaking down over time due to the salt. Not sure if this just counter-marketing from chlorine pool people, or if it is legitimate. Does anyone have any info on real problems encountered with saltwater pools or if special material is needed to encase saltwater in a saltwater pool.
Comment: Thanks a lot for the detailed response! And sorry for the delay in accepting the answer - still new at this. We went ahead with the saltwater conversion and everything has been looking good for the past few months. Will have to do some research to see if things were installed correctly...also liked Bahtmans answer! Thanks again!
Answer: From my personal and professional experience with Saltwater Pools with "Salt Chlorine Generators" on them has always been positive. I will bullet point some information to help you ensure it's a positive experience:
Correct Installation:
The Salt Chlorinator Systems have 2 main parts.

A "Salt Chlorine Generator Cell" that is spliced into the return side of the PVC usually directly after your filter or heater. (Important Note: Ensure that the salt cell is installed as the last place in the PVC that returns to the pool. If you install it say before a heater or before the filter, then when the salt cell converts the salt to chlorine, you will have a high concentration of fresh chlorine (which is very corrosive). Chlorine is basically double the strength of Bleach and is used in your pool to sanitize and eat up/destroy organic matter in your pool. Remember, that single cell has to create enough chlorine to sanitize and be useful in a, say, average pool of 15,000 gallons. So the chlorine level directly after the cell is well over a "readable" level (20PPM+) but once it gets to your pool, it instantly dilutes to a more preferred level of 3 PPM - 5 PPM.
A "Salt Generator Control Box" is usually installed by your pool equipment on the wall and is connected to your pool's power source (so that it only runs when your pool is running and circulating water) and it also connects to your "Salt Chlorine Generator Cell" (which is what provides the electrical power to turn the salt into chlorine. There is also usually a built-in flow meter to ensure that there is water flowing at a minimum rate to protect the system).
EXPERT TIP - A final part of the installation is not included with your purchase of a Salt Chlorine Generator system for your pool, but I recommend it for ALL pools that have some type of automatic chlorinator on them. That part is a Standard PVC Check Valve, which you have installed Just Before the Salt Cell. A Check Valve is a simple PVC adapter you can get at any local hardware/plumbing store (Home Depot/Lowes) for $1 and what it does is allows water to only flow ONE WAY through the valve; if water tries to flow the wrong way the check valve stops the water. This is important for many reasons but, on this topic, this will ensure that when your pool equipment turns off each day, the Very Concentrated Chlorine water made by the Salt Cell does not "drain back into your pool heater, filter, pump, etc. and basically sit there and corrode your o-rings, gaskets, etc.... I've seen the damage countless times from this. You can Google "PVC Check Valve" to understand it more if you want, but it's a very simple part to be installed during installation of the salt chlorine cell and should only be at most $10 extra for installation & the check valve. If you're doing a personal install, pool equipment uses 1.5" or 2" PVC pipe; ensure you know which you have to get a check valve that fits.

Salt Chlorine Generator Facts:
These simple facts that compare the amount of salt your pool will require for a salt chlorine generator vs a tear from a human eye vs Ocean Salt Water.

The average Salt Chlorine Generator requires 3,000 PPM of salt in your pool to operate correctly (Check instructions for exact amount of the system you buy).
Everyone has probably cried enough before to get a tear on your lips or in your mouth. A human tear normally has 9,000 PPM of salt
The Salt Water from the Ocean such as the Gulf of Mexico has 20,000 PPM of salt

We sell Thousands of Salt Chlorine Generators A Year All Over The World. To this day, I'm not aware of ONE single customer who was unhappy and wanted a refund after they installed it. In my last house, I had a pool built and I used a salt chlorine generator from day one. I can say that the 3,000 PPM of Salt Required in the pool makes the pool water feel "soft" on your skin vs the normal "dry" feeling from a liquid/powder chlorine pool. I also only had to clean the cell 2 times in the 8 years I lived there and it ran every day without any other issues.
Common Issues:

Ensure You Clean Your Filter Often - There will be times that you may see that your salt chlorine generator isn't on due to "flow" (some systems will just turn off). Always check and clean your filter as a dirty/old filter will slow down the water flow enough to make your salt system not work. Do this before dishing out $300+ for a new "Salt Cell".
Clean Your Cell* - Basically every pool requires calcium for proper water balance. This calcium with time will start to collect on the salt cell. When you remove the salt cell (which should be installed on **Union PVC Connectors so you can easily unscrew the salt cell for cleaning vs having to have a pool repair tech out to cut into your PVC again) use the manufacturer's directions on cleaning your cell. To clean the salt cell on my pool required a mixture of about 70% water and 30% Muriatic Acid in a bucket in which you place your cell and you will start to see it bubble and foam, which is the acid eating the calcium deposits off the metal blades of the cell. EXPERT WARNING - Muriatic Acid is VERY dangerous and if poured onto concrete or your body it will eat a hole right through it, so be very careful when handling Muriatic Acid. EXPERT WARNING - Muriatic Acid if mixed with Chlorine creates "Mustard Gas" and is deadly if breathed in. So don't think of adding chlorine to the cleaning bucket like I've heard of people recommending before.

Well that's my 2 cents and facts I know from selling tens of thousands of salt chlorine generators over the past 10 years online and it's still one of our top selling product lines.
Happy Swimming!
Comment: Hi, and welcome to the site. This is a great first post with lots of information. I edited out your signature since the link to your user profile appears with every contribution (see http://diy.stackexchange.com/help/behavior for more information).
Comment: This sure reads like an advertisement to me.  Any references for any of this?
Answer: The term "saltwater pool" is a bit misleading.
I was a builder in TX. and 95% of my pools had that system.
Simply put, adding a chlorine generator is just that.
A system to generate chlorine, from sodium chloride (salt).
The system changes the salt you've added to your pool water into a chlorine gas and eliminates the need for you to add chlorine maunally.
Benifits: After the overall cost of the system (size of the unit is based on total gallons)salt is pretty darn cheap. A lot less than chlorine tabs or powder, so you'll save some money. Chlorine is caustic and a carcinogen. Totally unsafe.
"Chlorine tanks ruptured after train wreck" "Towns evacuated, people suffer burns"
Salt on the other hand, is sitting in your kitchen.
(Same as pool salt but iodine has beed added).
The chlorine gas entering your pool does not produce chlorimines which cause burning eyes, itchy skin, yellow hair and bleached out bathing suits.
Disadvantages? Well if you add to much salt into the pool, you will taste it.
If added properly there will be no taste involved and most systems have an "add salt" light and a "correct range" setting in PPM.
Simply put...........add the system, with self reversing polarity (self cleaning).
Most systems are guaranteed for at least 5 years.
The sun will deterioate your liner more that the chlorine will if used properly.
Remember, all your doing is producing your own chlorine instead of buying it.
Comment: Hi I'm getting my pool converted next week. If I post a picture of my current setup would you let me know where it should be installed?


Difference between chained and migrated rows

Question: What is the difference between chained and migrated rows? Also what query should be used to display these rows? (I'm using Oracle 11gR2 database)
Answer: Chained and Migrated Rows are explained in the Logical Storage Structures of the Concepts Guide.
A migrated row would be a row who's column data was completely transferred from one block to another due to an update. The original block would essentially only have a "forwarding address" stored for that row.
A chained row would have parts of its column data in multiple blocks. The original block would contain both actual column data and a forwarding address for the rest of it. (You can get rows chained to more than two blocks.)
Both are implemented the same way deep down, so they're really two aspects of the same thing.
Also note that for tables with more than 255 columns, all rows are technically chained - one "row piece" can only contain 255 column values. The chaining can happen in the same block, or with other blocks depending on space availability (and isn't particularly "bad" if all the data ends up in the same block).
The only way, as far as I know, to get accurate data on row chaining is to use:
ANALYZE TABLE your_table [partition (your_part)] LIST CHAINED ROWS

See Listing Chained Rows of Tables and Clusters.
This is potentially expensive, the whole table needs to be scanned. Statistics gathering doesn't fill the CHAIN_CNT column of the dba_tables view. (I think it might have at some point, but it doesn't in 11.2 at least.)
You can monitor the table fetch continued row1 statistic (v$sysstat) to see if a query is affected by chained or migrated rows, but I don't believe you can have that metric per-session so either you need a quiet system to measure, or the reading will be "noisy".
The Secrets of Oracle Row Chaining and Migration has interesting information about chained and migrated rows, how you measure them, and potential ways of fixing them.
As always, don't go about rebuilding tables or changing storage parameters "just because" you see chained or migrated rows. Do so only if you measure that it's actually causing you performance problems.
1 From Statistics Descriptions:

Number of times a chained or migrated row is encountered during a fetch
Retrieving rows that span more than one block increases the logical I/O by a factor that corresponds to the number of blocks than need to be accessed. Exporting and re-importing may eliminate this problem. Evaluate the settings for the storage parameters PCTFREE and PCTUSED. This problem cannot be fixed if rows are larger than database blocks (for example, if the LONG datatype is used and the rows are extremely large).

See also Table Fetch by Continued Row.
Answer: A more "proactive" way to find if you have issues with chained rows is to use OEM and the segment Advisor.  (Administration –> Storage –> Segment Advisor -> Chained Row Analysis)
Segment Advisor runs on a schedule and looks for curiously long operations that might signal a chained row issue.  It then does a deeper analysis during your database's maintenance window, and gives you the option to correct the problem...but I prefer to correct the problem outside of OEM.
To resolve the problem, you have a few options.  Reading the answer above, its strange that a recent Oracle doc mentions doing an export/import...that works, but its probably not the fastest or easiest option.
A much faster way than an export/import is to do an "alter table table_name move;"...which will reorg the table in the same tablespace.  This can also be done parallelized. After that, you'll need to rebuild all the indexes on that table.
Another (online) option is to use dbms_redefinition. This is great when it works, but its more complicated than the other options.
You could also do an insert into a new table, (insert into new_table_name select * from table_name), rename the tables so the new table has the old name and then rebuild the indexes.
In my experience the best way is usually the alter table move, unless you have storage capacity constraints.


Scholars nowadays seem to have a reservoir of knowledge and brain on islamic sciences. Why then are the first 3 generations the most knowledgeable?

Question: The scholars of Islam now days study Islam 16 hours a day. They read so many books that they seem to have a reservoir of brain. They read so many tafsirs, fiqh, akide and study in details even a single word from the Quran. They study all that religious experience of 14 centuries. They have an entire science for studying even one branch of islam like hadith science, fiqh science etj... Every tag in islam stack exchange is a science. My question is: Why then do we say that the most knowledgeable people are Abu Bakr,then Omar,then those closer to him?? Then the tabiine, then the first three good generations.
Comment: Who says that the first 3 generations are the most knowledgeable? Could you provide any evidence or source for that?
Comment: Unfortunately, many of the 'scholars' of today do not practice what they preach. This differentiates the first 3 generations from them. Many people in Arabia converted by just observing the behavior of the Prophet & the Sahaba, Tabain & Tabe Tabain. Very few of today's scholars can truthfully claim to be on par with them.
Answer: It is because the source of the knowledge is the Prophet. The companions observed and learned from the prophet directly for several decades and were intimately familiar with the context of the revelation of the Quraan and Quraanic Arabic was their mother tongue in which they were experts. Only a fraction of their knowledge is preserved and passed onto modern scholars. Even from the generation of the Tabieen, there are those who it is said that they had memorised more ahadith than the total number of ahadith that are present today in books all together.
Comment: If somebody -in the early days- memorized more hadith than we have present today that doesn't necessarily means that there are many ahadith missing today. It means they have narrated more versions of ahadith as each narrator chain + hadith content counts as one hadith. Al-Hafidh ibn Hajar for example often points at differences in the narrations of Students of imam al-Bukhari of the same hadith.


Problem in clicking on icon

Question: I am trying to click the image icon via xPath, but when I run the code the link present on image icon is not opening. Could you please help me in resolving this issue?
Comment: Would you mind providing the sample html where you got the problem identifying the element?
Answer: Maybe your xpath is wrong. You can use add-on FirePath for Firefox to get the xpath of the image. In order to let the link be clicked, your xpath should end with tag a, not img.
For example, suppose xpath of the image is .//*[@id='navbar_notice_6']/p/a/img, you should remove /img, then your command in java will be:
driver.findElement(By.xpath(".//*[@id='navbar_notice_6']/p/a")).click();

Problem in clicking on icon


Fuel meter strange behaviour

Question: Every morning fuel meter of my scooter  shows reduction in my fuel level from previous night fuel level.Initially i thought it could be some leakage issue I have analysed this but there seems to be no leakages nor there is any smell of petrol .I have noticed the similar behaviour at day time also after parking my vehicle for some time and riding it back.
Comment: Are you sure it's not reading differently because it's on the kickstand?
Comment: No this is not the case I park my vehicle on main stand
Comment: The main stand tips the scooter forward a bit, that could be the reason.
Comment: I did not get the meaning for **the main stand tips the scooter**
Comment: I'll put it in an answer.
Comment: Do you have a locking fuel cap? Is there a possibility that someone is syphoning fuel out of the tank?
Comment: Yes I have a lock for it and I do not suspect anyone stealing the fuel out of the tank
Answer: You have not said how much of a reduction, so this is just some basic theory.
Fuel level gauges are for reference. They are not precise measuring devices.
That being said, while your scooter is moving, the fuel is sloshing around the tank making the fuel level float rise and fall. The gauge will only read what is an estimate of what it thinks is in the tank.
When you park the scooter, the fuel stops moving. So when you turn the scooter on again after time, the level appears to be lower.
After sitting overnight, there may be some contraction of the fuel as it cools from the previous day's heat. This simply depends on the climate you live it.
Your scooter probably doesn't hold a lot of fuel, so any small fluctuations will likely appear large on the gauge.
Comment: Yes this makes sense and  yes you are right fuel tank is small having capacity of only 5.3 litres
Answer: Fuel meters are usually designed to work when you scooter/motorcycle is level. Your fuel level mis-reading could be due to the kickstand or main (center) stand. When you use the kickstand the scooter will tip to the left, the fuel will go to the left side of the tank. When you use the main stand the back wheel is lifted off the ground, tipping the scooter forward. This will make the fuel run to the front of the tank. Either tipping to the left or forward might make the fuel gauge under-read. I've noticed this happen on a couple of my motorcycles.

Fuel meter strange behaviour


8000 TPS in EOS

Question: I have created a private network of 6 nodes in which 2 nodes are block producing nodes and remaining 4 are non-block producing nodes. I have changed block time from 0.5 sec to 1 sec.  I have to perform 8000 TPS so I posted 2000 transactions on each non-producing node but only 1000 – 1200 transactions get stored into the block. Can anyone suggest how can I perform 8000 transactions per second?
I tried to perform transactions using javascript api as well as using cleos.
Comment: Why did you change blocktime? And maybe your hardware is just not powerfull enough to perform 8000 TPS... I would also not recommend using a private network with 2 BPs in production, for testing it is viable.
Comment: Okay. Thanks @TeeAttack42  Do you mean, if I use better hardware then I can perform 8000 TPS?  Also Does change in block time will help?
Answer: If you need them all to be in one block, increase block time and max block cpu usage, and check you're using wabt and not wasm. All these can be configured in config.ini I believe.
Also ensure the action your calling uses minimum cpu, as you won't get anywhere near 8000tps for more expensive actions.

8000 TPS in EOS


How to export powershell output to excel

Question: I have found the custom lists in a particular site and I want to print the names to Excel. How do I do it?
Comment: You can try using steps in below URL: https://community.spiceworks.com/how_to/137203-create-an-excel-file-from-within-powershell
Comment: Script Saves numbers as text, would be nice to see one that doesn't convert integers and floats to text
Answer: Use the following Command:
$spWeb = Get-SPWeb SiteUrl
$spWeb.Lists | select Title | Export-CSV c:\Lists.csv

Answer: You can pipe the output from your command to an .csv file:
FileToExecute.ps1 | Out-File C:\output.csv

Make sure you in your script file uses Write-Outputand not Write-Host when printing your output.
Answer: You can export any output of the powershell to a CSV. This is a built in function.
Export-CSV
Answer: Try if this works:
Install-Module importexcel

If it works, then after that you can use export-excel command.
Answer: You wanna use the Export-Csv parameter. I also found this easy example.
SharePoint list to .csv file
Export-Csv
$MyWeb = WebUrl
$MyList = MyWeb.Lists["ListName"]
$MyItems = $MyList.Items
$MyItems | Select Fields.. | Export-Csv -path C:\example\excel.csv
$MyWeb.Dispose()

Answer: Using the Export-CSV as usual way we can export the SharePoint list items to a csv file, and using the below code we can convert the particular csv file to excel file:
### Set input and output path
$inputCSV = "C:\somefolder\input.csv"
$outputXLSX = "C:\somefolder\output.xlsx"

### Create a new Excel Workbook with one empty sheet
$excel = New-Object -ComObject excel.application
$workbook = $excel.Workbooks.Add(1)
$worksheet = $workbook.worksheets.Item(1)

### Build the QueryTables.Add command
### QueryTables does the same as when clicking "Data » From Text" in Excel
$TxtConnector = ("TEXT;" + $inputCSV)
$Connector = $worksheet.QueryTables.add($TxtConnector,$worksheet.Range("A1"))
$query = $worksheet.QueryTables.item($Connector.name)

### Set the delimiter (, or ;) according to your regional settings
$query.TextFileOtherDelimiter = $Excel.Application.International(5)

### Set the format to delimited and text for every column
### A trick to create an array of 2s is used with the preceding comma
$query.TextFileParseType  = 1
$query.TextFileColumnDataTypes = ,2 * $worksheet.Cells.Columns.Count
$query.AdjustColumnWidth = 1

### Execute & delete the import query
$query.Refresh()
$query.Delete()

### Save & close the Workbook as XLSX. Change the output extension for Excel 2003
$Workbook.SaveAs($outputXLSX,51)
$excel.Quit()

Reference URL:
How to export a CSV to Excel using Powershell
Note:

There is no direct inbuilt function to export in excel using PowerShell as like Export-CSV, so first we need to export to csv file, then we have to convert that file to excel.


Has there ever been an instance in Star Trek where someone beamed into a solid object?

Question: One of the many notable devices in Star Trek is the transporter, which can beam people to any set coordinates. Has there ever been an instance in any Star Trek story where someone was beamed into something solid? For example, someone's arm being trapped in a table or something because they were accidentally beamed into it.
Comment: not quite a transporter accident but the results of this subspace anomaly are pretty devastating: http://memory-alpha.wikia.com/wiki/Van_Mayter  -
Comment: Possibly the closest would be the Pegasus, which was more a form of phased cloaking, but, the ship was able to move itself into an asteroid
Comment: Related question is whether they've ever addressed what happens to the fluid that they are displacing when they transport into something that's not solid (air).
Comment: Related: [What happens to the air in the area, when things are transported or replicated?](http://scifi.stackexchange.com/q/22625/2242) - Includes an image of the top answer here
Comment: Can't find any sources, but my memory tells me that no, the transporter has never done this, but crewmen have made references to the possibility of it happening. I'll keep looking.
Answer: Per the Memory Alpha Transporter Section on Accidents there is no occasion listed in which there was an accidental beaming into another object.
That said, the closest such accident I would suggest would be the following:

In 2151, Crewman Ethan Novakovich was beamed back from the face of a planet later known as Archer IV by the still-experimental transporter system aboard Enterprise NX-01. The emergency transport was attempted during a fierce windstorm. Upon arrival, he was unconscious and had rocks, leaves, and other debris from the planet's surface embedded in his skin, due to a malfunction in the phase discriminator.

I would also suggest that the situation with the Pegasus embedded in Asteroid Gamma 601 was more of a cloaking device issue than a transporter.  Hence, would not qualify as an answer to the question. But, would logically be a similar type of accident as would the Van Mayter accident noted above in the comments (which was due to a natural sub-space anomaly vs. technology issue).
Also see the Wiki page on Asteroid Gamma 601
Comment: Not sure if it was a replicator or transporter, but I believe when the Kazon had an accident with Federation technology, they showed dead Kazons who were melded into the bulkhead of their ship.
Comment: @Boann: That's a debatable case then, as (unlike the Pegasus's phase cloaking), replicators and conventional transporters are closely related technologies.
Comment: @Lèsemajesté Voyager S01E11 - State of Flux. It was a replicator, used without proper shielding.
Answer: In the TNG episode "The Schizoid Man" (season 2), an away team was beamed to a planet while the Enterprise was either still using warp power or had briefly dropped out of warp long enough to use the transporter.  I forget the exact details but, after the away team arrives, Counselor Troi said something like, "For a moment I thought I was in that wall over there" and Worf replied, "For a moment, you were."
Comment: Excellent, in a sense this is closest to a precise answer to the specific question.
Comment: This might be better edited into http://scifi.stackexchange.com/a/139880/12616
Comment: they weren't actually transported into the wall though, they were transported to an open location without obstructions but the path the beam took was temporarily out of phase because of the speed the ship was moving when the transport occurred.  very close I agree, @JoeBlow
Answer: The possibility is mentioned:
In "The Cage"

ONE: Now, you all know the situation. We're hoping to transport down inside the Talosian community.
  SPOCK: If our measurements and readings are an illusion also, one could find oneself materialised inside solid rock.
  ONE: Nothing will be said if any volunteer wants to back out.

Repeated in "The Menagerie part 2"

NUMBER ONE: Now, you all know the situation. We're hoping to transport down inside the Talosian community.
  SPOCK: If our measurements and readings are an illusion also, one could find oneself materialised inside solid rock.
  NUMBER ONE: Nothing will be said if any volunteer wants to back out.

In "Return to Tomorrow"

SARGON [OC]: I have locked your transporter device on my co-ordinates. Please come to us. Rescue us from oblivion.
  SPOCK: Coming from deep under the planet's surface, Captain. Under at least one hundred miles of solid rock.
  SARGON [OC]: I will make it possible for your transporter to beam you that deep beneath the surface. Have no fear.
  SPOCK: Reading a chamber now. Oxygen-nitrogen atmosphere, suitable for human life support.
SCOTT: I don't like it, sir. The transporter co-ordinates preset by an alien of some sort. You could materialise inside solid rock.
  MCCOY: Inside solid rock?
  SPOCK: Unlikely. These co-ordinates correspond with the location of the subterranean chamber.
  KIRK: I have a feeling that they or it could destroy us just standing here if they or it wanted to.
  MULHALL: They or it?

And in "The Savage Curtain"

MCCOY: Yes, a big one. Suddenly, miraculously, we see a small spot of Earth-type environment down there. Now is it really there, or do we just think we see it down there?
  SCOTT: You might beam down into a sea of molten lava.
  KIRK: But why would he want to kill only two of us?
  SPOCK: It would be illogical. With such abilities, they could as easily trick us into destroying the entire vessel.

So that is something that is definitely considered to be possible disaster.
I don't know why they don't worry about materializing in air and getting air bubbles in their bloodstreams.
And also in Star Trek II: The Wath of Khan

SAAVIK: This is not logical. These coordinates are deep inside Regula, ...a planetoid we know to be lifeless.
  KIRK: If Stage Two was completed, it was going to be underground. ...It was going to be underground, she said.
KIRK: Right! Let's go. ...Saavik.
  McCOY: Go? Where are we going?
  KIRK: Where they went.
  McCOY: Suppose they went nowhere.
  KIRK: Then this'll be your big chance to get away from it all.

Thanks to ClickRick for mentioning the last one.
Comment: Pattern Buffers and Phase Discriminators are the reason they don't worry about air in the bloodstream thing
Comment: I had a vague memory that the same line was used in one of the films - either ST2 or ST3 - when going down into the chamber, but can't find a reference to back that up.
Answer: While definitely non-canon, the "Choose Your Own Adventure" style book Star Trek: Phaser Fight includes a sequence that explores beaming into solid matter:

"Well, if you must," sighs Jinks. "The planet's surface is a bit tricky, so to be safe, you ought to beam down to the following coordinates: 33.51.62".
"That's solid rock," says Mr. Spock to the captain.
"I know," Kirk agrees.

You have the choice to go ahead and beam down at those coordinates.

"It's none of my business, sir", you pipe up, full of confidence, "but our readings were wrong when they told us that there wasn't any life on the planet. The readings are probably wrong about those coordinates being solid rock..."

But it doesn't go well...

You beam down to the surface of the planet. Or, more accurately, into the surface of the planet!
You beamed down into solid rock! The only part of you that's visible
above the rock is your hair!
Well, hair today, gone tomorrow!
Comment: No worries. Although everyone and their dog slated this CYOA book, I recall quite liking it as a kid.
Comment: @Valorum I loved it too. It was a library book for me, so I couldn't keep it, but I always figured it would be around again. Pity that it seems to have wound up in a library book sale because they don't have it any more.
Comment: Ick, that's grim.
Comment: Upvoted for "Hair today, gone tomorrow". Can't stop giggling.
Answer: If people count as solid objects, then yes.

Tuvix was a hybrid being created as the result of a transporter
  accident on the USS Voyager, combining Lieutenant Tuvok, Neelix, their
  uniforms, and an orchid in 2372.

Although it might not count, because two transporter streams were merged.
Comment: Don't cross the streams!
Comment: I agree with your last statement, that this doesn't fit the spirit of the question. The event you describe involves *both objects* being decomposed into a matter stream and then reassembled incorrectly (due to the presence of a foreign material). One isn't "beamed into" the other so much as they are "beamed together."
Answer: It is a paradoxical question, if they have figured out how to transport someone without getting all their pieces mixed up with the atmosphere then they should not have to worry about mixing up their body with solid rock.
It should not be possible to transport into rock/stone because your body would have to have space to take up, the rock would have to move from the spot where you materialize, or be displaced. I think there would be some sort of feedback in the matter stream back to the source of transport if you tried to transport into something solid that could not be displaced by the introduction of another object.
Trying to beam into a location where the matter is not easily displaced would not be possible, The beam would be pushed back because the Rock/Stone would not give.
I would be more worried about beaming into Water or some sort of Gas or possibly even Lava as these substances will displace themselves around something being introduced into the midst of them, in other words these things will make room for the object being materialized.
The Matter Stream would not merge Matter from the stream with something outside of the stream.  In the case of Neelix and Tuvok, they were both inside the matter stream(s) and materialized, from energy to matter, together, not into one another, from Energy to matter in the same space as Matter already existing in that space.

In the TNG episode "The Schizoid Man" (season 2), an away team was
  beamed to a planet while the Enterprise was either still using warp
  power, or had briefly dropped out of warp long enough to use the
  transporter. I forget the exact details, but after the away team
  arrives, Counselor Troi said something like "For a moment, I thought I
  was in that wall over there", and Worf replied "For a moment, you
  were."

This is because they were temporarily out of phase, which is different than the wall and the person existing, in the same place, at the same time, in the same phase, this is the same reason why the USS Pegasus had its incident in the asteroid, it was out of phase and came back into phase inside of the rock.
That is why they have the Phase Discriminator.  From its uses, it appears that it does two things

Makes sure that matter not being transported isn't merged with matter that is being transported

In 2151, when Malcolm Reed attempted to beam Crewman Ethan Novakovich up from the surface of a planet during a powerful windstorm, Novakovich rematerialized with debris embedded in his skin, due to the transporter's phase discriminator's inability to isolate the debris from the matter stream. (ENT: "Strange New World")

Keep transported matter in the same "phase"(Time) from source to destination

So when transporting at near warp they existed through more than one "phase", so this is a little different than just straight transporting into Rock/Stone
With Pegasus, the ship and the asteroid existed in the same location but at a different time/phase and when the phase was normalized to the same phase as the rock there were no safeguards to keep the molecules from moving around and merging, which is why the accident happened.
For reference see Phase Discriminator on Memory Alpha

An Afterthought
I think that people in the future may be just as paranoid as we are, for instance if you were told to go into a cave without turning on your flashlight until you are already inside the cave at the predetermined location and then turn on your flashlight, you would probably not like it at all.  so you would want to find out where you are beaming to and maybe see it before you just beam to that location.  putting your faith in technology like this is going to be hard, I would assume that they would scan the location and probably not "beam" to a location they could not see.  I also assume that their imaginations would run wild around the issue of beaming somewhere they could not first see, they would come up with all sorts of mythical issues that sound reasonable but maybe not possible, this would lead to the many discussions that other answers describe.  This sort of thing happens today all over Social Media, there is no reason to believe that people of the future would not let their imaginations run wild, I know that most of these characters are very knowledgeable in the science behind the transporter, but I would say there is plenty that they don't know and plenty that they speculate on as well, causing the same imaginative ideas to pop up.
Comment: It occurs to me that we're always worried about ending up inside solid rock if the coordinates are wrong. Why is nobody ever worried about materializing 300 feet in the air and falling to their death? Maybe there is something to the idea of feedback on the "matter stream" after all...
Comment: @Brad: hard or easy, if you achieved it the result probably should detonate, since two stable solids interleaved don't (generally speaking) make a stable solid. For the same reason that the molecules in either of the solids alone "want to be" (that is, are stable) a certain distance apart, once you interleave they're closer together than they want to be.
Comment: But solid objects are mostly empty space. Would inserting molecules between other molecules be that hard? (not to say there aren't checks in place like the phase discriminator but that seems like it would make it less likely, not impossible.)
Comment: Even if you did "safely" beam into solid rock (the rock molecules are moved away somehow) you would be trapped motionless with no air and would suffocate very quickly.
Comment: the empty space between molecules is empty for a reason, and it is a powerful reason, and that reason makes nuclear energy possible, both fission and fusion.  Fusion would be what would happen if you tried to disable all the safeguards and "beam" a person into rock.  that is why I was saying that I think there would be feedback, I am thinking like if you try to fill a hose with the one end plugged, the fluid would comeback or stay in the hose because there is nowhere for it to go
Answer: Not a personal accident, but the USS Pegasus was equipped with a phasing technology that failed halfway through an asteroid and made it materialize in solid rock.
Answer: Every time the transporter is used, it is beaming into an object. Air. Air is no more or less special than stone.
Since people don't come out of the transporter carbonated and bubbly inside the air must have gone somewhere. It is either converted into energy by the same process as the sending side, or some kind of force field protects the destination area.
Comment: Or the transporter "simply" exchanges the two volumes of space?
Comment: The question asked about a *solid* object, though. And while air may not be more "special" than stone, it does not proceed that it has the same effects. For example, the transported object might quickly expand into being, with a pressure exerted on it proportional to the density of the surrounding material (the usual thing people are worried about with teleportation into solid objects). Or if the material is converted into energy, you might still end up stuck inside a wall. Or perhaps the substance transported into moves away rapidly, which would be a lot more noticeable for solid objects.
Comment: I figure the annular confinement beam mentioned several times is a kind of force field that pushes stuff out of the way then keeps it out as the object materializes.
Comment: @Adamant and Zan: Good points, both of you. Was there ever an time when this was mentioned as a concern, for instance, stating a point when the pressure of the surrounding gaseous medium was too high and operations where inhibited?  I certainly remember scenes where extant environmental conditions caused beaming problems but I can't recall at the moment anything specific to density or the composition of atmosphere solely in itself.
Answer: I'm certain this occurred in an early episode of Enterprise where they used the transporter technology only for transporting cargo. They experimentally use it to transport people, and those people end up with bits of leaves and stuff sticking out of them but as far as I recall, no serious ill effects.
Comment: The episode you're thinking of is "Strange New World." From Memory Alpha: "The captain finally decides to get the away team back to Enterprise but the shuttle is unable to land.... The away team is then forced back in the cave.... However, since Novakovich would not go in the cave with the others, it is decided to use the still experimental transporter to bring him back. The transporter is unable to distinguish between Novakovich and the plant life being blown around him, several leaves are embedded in his skin as a result."  Link: http://memory-alpha.wikia.com/wiki/Strange_New_World_(episode)
Comment: Thanks for the link! So happy to know I remembered it correctly as well
Answer: I vaguely recall that this has happened during transporter accidents, but I can't find an episode where it is actually shown, it just might have been somebody talking about it or something.
However, there definitely has been at least one case that we see onscreen case where multiple people are beamed into a solid object (a wall) although only temporarily.  This is a side effect of a near warp transport, and does not appear to be in, any way, harmful.
Answer: If water fits the definition of "solid" (technically no, but in terms of imagined results I'd say yes), then in the 2009 Star Trek movie, when Kirk and Scotty are beamed long-distance onto the Enterprise, Scotty ends up in an enormous, water-filled pipe.
Comment: Okay but he wasn't beamed "into" the water, otherwise he'd have been killed instantly. He was beamed into a space previously occupied by (and entirely surrounded by) water, yes, but that's no different from how they're usually beamed into a space previously occupied by (and mostly surrounded by) air.
Comment: @LightnessRacesinOrbit So, you think the transporter removed a Scotty-shaped blob of water at the same time as it installed a Scotty-shaped blob of Scotty? Is there any in-universe support for this feature of the transporter?
Comment: What else would it do? The only alternative is to molecularly merge Scotty with the water. The fact that it is obviously not possible to survive such a state is all the evidence required.
Answer: In the non-canon Millennium trilogy of DS9 novels, Chief O'Brien is running a deep scan of the station when he turns up two dead Cardassians fused into a hull plate. After eliminating the possibility that they were sealed inside during manufacturing (according to Kira, even during the Occupation, Cardassian quality assurance would've picked up on something so obvious), he concludes that they must have been transported into the plate and that because of the sheer number of safeguards against such an accident, it must have been deliberate, i.e., murder.

 Eventually, the crew determines that the incident was in fact an accident involving a time machine, which was in the process of powering down and so threw the Cardassians back a shorter time than expected. Instead of the room they expected, they appeared inside the wall due to the station's rotation.
Answer: In the TNG episode "The Last Outpost", an energy field on the planet interferes with the transporter beam, and I seem to remember someone's foot being stuck in the ceiling of the cave (he was hanging upside down).
Comment: you're close - it was Geordi, but he's not in a cave, he merely materialized upside down and is hanging by his foot in a tree - you can see that here: http://imgur.com/KfirSqK
Comment: Someone [already mentioned this](https://scifi.stackexchange.com/a/139876/50530).


Prioritize visible content Google Page Insights

Question: I am having an issue with a section on my home page "Featured Products". When I test on google page insights it is listing as Suggestions. With this my mobile optimization is 42/100, when I remove just this section it improves to 83/100 and Prioritize Visible Content is no longer listed as a suggestion. Any suggestions on what I can do to fix this without changing this section. I am not sure of any other content I can replace it with to display the featured products properly.
www.premiermediaav.com
Answer: as your website is responsive,  it is wise to reduce content for mobile view since google page speed testing using different connection between desktop and mobile,  it's still okay if in desktop your page is loaded 1-2 mb size, but for mobile view it not too efficient since mobile supposed have poor connection,  although in real life some people use same connection between mobile and desktop.  but its better to make your page simpler as possible when user open on the mobile, and I think it will related with bounced rate too.. big size your page will take longer time to complete load your page it will cause the most users wont be patience to wait and they will leave your website.
so for mobile it better to filter again some content that you loaded, make simpler design for mobile not just convert your desktop page be smaller in mobile but let size the content like image still have same size as desktop size.
the alternative way,  maybe you can use secondary image when it loaded in mobile size..  so when user open your page and it will cost smaller size and faster loading time.
hope this helps.
Comment: Is it the images in that section are the text/links below the images causing the issue
Comment: you can check in the inspect element (I assumed you using google chrome browser)  then go to the network tab,  you will see all loaded component (js, css and images) on your website with the size as well, and from that you can decide what component have big size,  if it image try reduce resolution and size for mobile size,  if it from css and js try to minify then merge it.


What would be the difference in distance between earth and moon on supermoon night (14 November 2016)

Question: As we all know the usual distance between earth and moon is 384,400 km.
But i was thinking how much closer it will be on 14 November 2016, as it will be a supermoon, the brightest and biggest moon in 60 years.
Comment: This is really far too simple a question to be worth keeping in this site.
Comment: http://www.space.com/34660-closest-supermoon-full-moon-in-69-years-forecast.html
Comment: You may or may not find my https://astronomy.stackexchange.com/questions/19043/how-can-the-next-supermoon-be-analytically-predicted/19052#19052 useful.
Answer: Based on some information from this article
http://www.space.com/34515-supermoon-guide.html
The Nov 14 2016 supermooon's expected peak of full phase
is on the morning ov Nov 14 at 8:52 AM EST
According to some quick calculations that I performed
using PyEphem
and assuming the moon would be viewed by an observer in NYC at 08:52AM EST
0.00236372323707 AU from observer
An AU is 1.5 * 10^km
Edit: I needed a better precision for km to AU
http://www.iau.org/static/resolutions/IAU2012_English.pdf
According to this, the AU can be more precisely defined as
149 597 870 700  meters +/- 3 meters
0.00236372323707 * 149 597 870 700 =
353 607 963.19 meters or
~ 353,608 km from earth
here is a quick run through of the inputs I used for the program
<code>>>> moon = ephem.Moon()
>>> nyc = ephem.Observer()
>>> nyc.long, nyc.lat = '-74.0059', '40.7127'
>>> nyc.date = '2016/11/14 08:52:00'
>>> moon.compute(nyc)
>>> print moon.earth_distance

    0.00236372323707
</code>
Learn more about PyEphem package here
http://rhodesmill.org/pyephem/index.html
Note I'm just an amateur and these calculations might not take in certain critical factors. I'm uncertain if PyEphems earth_distance property calculates distance to the moon or the moon's center.
If it does calculate distance to the center of the moon this number could be about ~1700 km smaller.
Given your figure of 384,400 km average, this would put the moon just under
~30 792 km closer to the earth or about 91.98 % of it's normal distance
Comment: How do you multiply by something with two significant figure precision to get something quoted to 7 significant figures?
Comment: Good point. I need a better figure for KM per AU
Answer: From where I am on Vancouver Island,  western Canada, it will be around 356,500 km.
Comment: In this case, it would be a good idea stating your source.


In what order should I watch the films in the Marvel Cinematic Universe?

Question: What films make up the Marvel Cinematic Universe, and what order should they be watched in?
Comment: Watch them in the order they were released.
Answer: The full chronological (not release order! I assume you're asking for chronological, as release order is easy enough to find on Wikipedia) order, bolded the ones that interest (and/or should) you:

Captain America: The First Avenger (Film)
Agent Carter (One-Shot on the Iron Man 3 Blu-Ray)
Agent Carter (TV series)
Iron Man (Film)

A Funny Thing Happened on the Way to Thor's Hammer (One-Shot on the
    Captain America: The First Avenger Blu-Ray)

Thor (Film)
The Incredible Hulk (2008 Film)
Iron Man 2 (Film) (Hulk's campus rampage can be seen in the background)
The Consultant (One-Shot on Thor Blu-Ray)
The Avengers (Film)
Item 47 (One-Shot on The Avengers Blu-Ray)
Iron Man 3 (Film)
Agents of SHIELD (TV Series: Season 1, Episodes 1-7)
All Hail The King (One-Shot on the Thor 2: The Dark World Blu-Ray
  and digital release)
Thor 2: The Dark World (Film)
Agents of SHIELD (TV Series: Season 1, Episodes 8-16)
Captain America: The Winter Soldier (Film)
Agents of SHIELD (TV Series: Season 1, Episodes 17-22)
Guardians of the Galaxy (Film)
Daredevil (Netflix Series)
Agents of SHIELD (TV Series: Season 2, Episodes 1-19)
Avengers: Age of Ultron (Film)
Ant-Man (Film)
Agents of SHIELD (TV Series: Season 2, Episodes 20-22)

List taken from this source. The list was compiled based on clues and/or direct references made between movies and/or info released by creators. I've changed it a little, as the original list was a little inaccurate.
Note that some films are likely happening simultaneously - like Iron Man and The Incredible Hulk.

 Tony Stark's organisation sold anti-Hulk weapons to the army (that had to happen before Tony returned from captivity), and yet at the end he approaches the General with the Avengers initiative as a solution to Hulk (after finishing his first bossfight as IronMan).
Comment: Hmmmm... what's the justification behind watching Ant-Man before the rest of SHIELD season 2?
Comment: @scott.korin that part I don't know. Copies from the source website. I haven't watched either yet, so I didn't read into it to avoid spoilers
Answer: You probably shouldn't discuss piracy on Stack Exchange – at least, the use of download implied this, sorry if I'm wrong.
Anyway, related to the Avengers, you appear to be missing Thor, Thor 2: The Dark World and Captain America: The Winter Soldier. As you'd expect, you should watch them in release order:

Iron Man (May 2008)
The Incredible Hulk (June 2008)
Iron Man 2 (May 2010)
Thor (May 2011)
Captain America: The First Avenger (July 2011)
Marvel's The Avengers (May 2012)
Iron Man 3 (May 2013)
Thor: The Dark World (November 2013)
Captain America: The Winter Soldier (April 2014)
Avengers: Age of Ultron (July 2015)

The Marvel Cinematic Universe will probably have a lot of development towards non-Avengers by Infinity War. Only Guardians of the Galaxy and Ant-Man fit that category so far, but I recommend you watch them after Captain America: The Winter Soldier to fully understand a few tidbits of plot (which I won't spoil).


Replacing contact form with chatbot

Question: I'm redesigning the user experience in a portal for a IT company. I'd like to know if anyone has done a study on pro & cons to replace the contact form page with a chatbot, or more general if anyone has experience in.
Answer: There is already something like that for you, made by Amazon.
From the page:

Amazon Lex is a service for building conversational interfaces into
  any application using voice and text. Lex provides the advanced deep
  learning functionalities of automatic speech recognition (ASR) for
  converting speech to text, and natural language understanding (NLU) to
  recognize the intent of the text, to enable you to build applications
  with highly engaging user experiences and lifelike conversational
  interactions.

So, there is already an API to put that into your app and have a bot talking to you.
Amazon claims to already have several customers using the bot on their pages, including OhioHealth, CapitalOne, HubSpot and NASA.
Comment: Interesting, but this doesn't answer the question of pros and cons from a user experience point of view.
Answer: Chatbots are a good thing if implemented right, in my point of view
I view chatbots as search-centric information interfaces. For help and other kinds of documents, it is definitely a plus. Of course the quality of the docs and provided functions are the real challenge.
The chatbots I talked to so far are the dumbest search engines I saw. This has not bothered me at all. After a few questions I learned that it is more efficient to send just the keywords of what I was looking for.
I think the challenge is to write the info in a way that the bot will be able to index right. If there are too many documents and unclear language, people will see many results for their inquiry and get annoyed.
Keep stats on inquires that does not satisfy the user, such as results presented but not clicked or explicitly set by the users as unhelpful. Establish a process to review those stats and update the docs seen by the bot or its programming.

Replacing contact form with chatbot


How does android wifi hotspot work when other wifi is available?

Question: Say I have my phone (nexus 4) setup as a wireless hotspot for my tablet to use while outside... Obviously this will make use of my mobile data plan. But when I get near a wifi signal that I regularly use, such as at home, will my phone continue to use my mobile data, or will it use wifi instead, and repeat the wifi signal? That is, do I have to remember to disable the hotspot every time I don't need it? And on that note, how can I make my nexus 7 prefer wifi other than my phone hotspot when available?
Answer: When your phone is in hotspot mode, it will only use your mobile data.  You'll need to remember to switch the hotspot off when you have wifi available.
You might be able to script the shutting down of the hotspot with Tasker or Locale, but I'm not sure if the "WiFi near" function would work when in hotspot mode (a good topic for its own question).
Your Nexus 7 will tend to connect to the strongest signal available, and then stay connected to that network until it loses the connection.    When you turn off the hotspot on your Nexus 4, the tablet should auto-connect to an available Wifi network.


What legal actions/procedures I can take as an indivdual to implement sugar law

Question: I would love to see a higher limit on sugar content in food, ideally not more than 15%, but a 40% is a start.
What legal actions/procedures I can take as an individual to get something put in law to prevent food companies from putting higher levels of sugar in their products?
Comment: I think this question might be a duplicate of [What's my change power in a democratic society?](https://politics.stackexchange.com/questions/10096/whats-my-change-power-in-a-democratic-society). Does this other question answer your question?
Comment: Related (not a dupe) https://politics.stackexchange.com/questions/31101/why-does-having-a-soda-tax-seem-so-hard-to-achieve-in-the-us
Answer: There are a few main things you can do:
Start a Petition
The government's e-petition website is a good place to start. As has been discussed previously on this site, these are rarely (or never) successful at directly affecting government policy. That does not, however, mean they are worthless as they can be useful to bring an idea into the public consciousness and make it more acceptable for people to talk about.
Contact your Representatives
In the UK, there are two useful points of contact for national issues like this. The first is your local MP. The second is the government department responsible for the policy area your point comes under (in this case The Department for Environment, Food and Rural Affairs) and the Minister in charge of it (here George Eustice).
There are three useful methods of contact:
Email
This is the easiest way to get in contact, but also the least likely to affect change. Emails can sit unread for a long time, and generally are considered to least useful way to get in touch.
Letters
Physical letters are the classic way of getting in touch with representatives. They give a physical quantifier of public opinion on an issue, and many politicians have stated that they pay most attention to the size (and contents!) of their mailbag.
Telephone Calls
These are also a good way of letting the depth of your feeling be known. They are an inherently personal experience, and they demand an immediate response. They do, however, require you to invest a large amount of time.
Organise a Peaceful Protest
If you want to make a more direct statement on an issue, you can try to find like-minded people and protest. Holding a march or rally can raise the public profile of your cause. You do, of course, need a group of people who will come together (the internet can be useful here). You should also ensure that you are aware of any notifications you need to make to law enforcement or the local authority, and any specific laws govenring such activities in your area.
Organise Direct Action
If you feel that your issue demands more than simple assembly, you can come up with direct actions to take to promote your agenda. if this appeals, it is worth looking at organisations such as Greenpeace for inspiration. It should be noted that his may involve breaking laws, which you may or may not be comfortable with.
Run for Office
If you feel that none of your representatives are listening, and you cannot get the public momentum you need to change their minds, or cannot translate that momentum into action, consider running for political office on a platform including this issue. There is, after all, no way to ensure that your representative listens to you than being that representative!
Comment: Answer could be improved by dropping the insinuation that direct action is a valid tool to get your way in politics.  Even worse to use an organization that engages in piracy(one of the few things international law recognizes as making you an enemy of all humanity) as a role model.  Especially when the question is about 'legal' procedures to do X.
Comment: @JackOfAllTrades234 I have a few objections. Not everything I would class as direct action is illegal. I picked Greenpeace because they are well known, and they deploy a range of tactics from their more confrontational actions to things like their brand attacks. I also would argue that a blanket opposition to illegal direct action is naive. Surely you don't object to the actions of Rosa Parks, Martin Luther King Jr., Nelson Mandela etc.
Comment: It may be that our definitions of direct action and peaceful protest diverge.  Rosa Parks to the best of my knowledge was known for her peaceful protests, as was Martin Luther King Jr.  Nelson Mandela however, while placed upon a pedestal, was a murderer, and fond of direct action.
Answer: You could try and find some activists, groups or NGOs that have the same vision of reducing the sugar content in food in general and contact them, perhaps help them in some way and become part of their organization/group.
Personally, you could probably create some sort of a lawsuit or petition, presumably with the help of a lawyer. The chance of achieving anything is however in this case very close to 0.
The last option from my point of view is to start some sort of activism yourself. You could perhaps create some organization/NGO or join politics that would represent your idea and help you market it. You need power/people/public reasoning and approval in order to be able and try to propose rapid changes such as this...


Stuck at 100% on the Noobs Installer

Question: I loaded the Noobs installer on my Raspberry Pi (B+ Model), then chose for both Raspbian & Raspbmc to be installed. I've been waiting for a long time now, it's on 100% and not doing anything (except showing all the "tips"). I'm worried that if I disconnect the pi It will mess up my micro sd card in some way. What should I do? I'm tempted to just disconnect it & try again.
Comment: If you are still waiting, lol, pull the plug and try again -- maybe one OS at a time?
Comment: is it possibly the power supply ( not enough voltage)?
Comment: booting a raspberry pi for the first time -- still a game of chutes and ladders after so many years
Answer: Disconnecting the Raspberry Pi will most likely solve the problem. Just remember that disconnecting Rpi straight from the power source will not cause physical nor driver damage to the SD Card. If you do reconnect and you find that the Raspberry Pi does not boot up or acts funny, reformat the SD card & reburn the OS (Noobs Image) back onto the Sd card.
If none of the above fix your issue, I suggest you manually install the image of your desired operating system (E.G: Openelec). The instructions are here: http://raspiserver.ngrok.com/hudenoqosu.mel

Stuck at 100% on the Noobs Installer


How is the corresponding author on a (math) paper typically chosen?

Question: I am preparing a joint paper with my mentor. I am a math postdoc. How is the corresponding author generally chosen? What are the benefits of being the corresponding author? Is it better for a post-doc's career if they are the corresponding author?
Answer: My experience as a pure mathematician in the US is that there are essentially no benefits to being the corresponding author. When I was a postdoc and in grad school I was often the corresponding author, but I get the feeling it was mostly because I was often the most junior of the authors and the others didn't want to waste time navigating editorial websites, receiving emails from the journal, mailing people tex files, etc. I would say that if someone is a pure mathematician in the US, the number of times they've been a corresponding author for a paper will have absolutely no impact on their career.
(I should add that I believe that in other countries the situation may be markedly different.)
Comment: More than in other countries, I think that corresponding authorship will matter in other fields of research. See here: https://academia.stackexchange.com/questions/10062/does-corresponding-author-carry-an-implied-meaning .
Comment: @FedericoPoloni Sure, but the question is about mathematics. Ben's answer covers the US, while acknowledging that other countries might be different in ways that are relevant to the question. Other subjects being different is irrelevant to the question.
Comment: One way to put it is that the benefit is the gratitude of your coauthors.
Comment: Or it depends on the institute culture. In my former university, the corresponding author was often one of the most senior authors (someone with a permanent position who's contact adress would most likely not change for a while).
Comment: Agreed. In my experience, I have no idea whatsoever who was the corresponding author on any multi-author paper I read, and I suspect that is the norm. It's hard for something to provide a career benefit when it's completely invisible to others!
Answer: As Ben Linowitz points out, the situation can be very different in other countries. In many places in Asia, for example, the significance of a publication on one's CV goes like this:
     publication as first author ≥ publication as corresponding author > publication as any other author.
The assumption here is that the first author contributed the most, while the corresponding author is the PI. Obviously, this should not apply to most mathematical publications where the authors are listed alphabetically, but university guidelines often do not take this into consideration...
Some countries will even put a quantitative value to this statement, explicitly weighting your publications based on the authorship order (in addition to other factors such as the impact factor). Here's an excerpt from Taipei Medical University's promotion standards (PDF):
<code>        Rank of author                       weighted points (A)
----------------------------------------------------------------
first author or corresponding author               5.0
2nd author                                         3.0
3rd author                                         1.0
4th or lower rank author                           0.5
</code>
In some cases things get even weirder — here's an excerpt from the regulations of Seoul National University (PDF):

Score of each research publication stated in Paragraph 1 of this article is as follows:
  1. Single author: 100 points
  2. Two authors: 70 points
  3. Three authors: 50 points
  4. Four authors or more: 30 points
   If applicant, however, is the first author or the corresponding author in a publication with three or more authors, he/she is entitled to 70 points.

Curiously, sometimes a corresponding author is worth more than first author. The Academic Ranking of World Universities, compiled by an agency in China and arguably one of the most influential international university rankings, uses the following scaling:

To distinguish the order of author affiliation, a weight of 100% is assigned for corresponding author affiliation, 50% for first author affiliation (second author affiliation if the first author affiliation is the same as corresponding author affiliation), 25% for the next author affiliation, and 10% for other author affiliations.

As you can see, there are often advantages to being corresponding author in such cases. Universities can offer additional incentives (e.g. monetary) for being first or corresponding author on high-impact publications, which often leads to more arguments and occurrences such as six "joint first" authors or, similarly, multiple "co-corresponding" authors on a paper.
Anecdotally, I would say that in non-Asian countries, such weighting is also frequently done but on an implicit basis, and is significantly more field-dependent. (For instance, the Korean university regulations do not distinguish between different fields, and I am unsure if different departments can have different rules — if not, I encourage every mathematician named Aaronson to apply for faculty positions in South Korea immediately.)
Comment: Essentially all the pure maths papers I've seen lists authors alphabetically. This is independent of what country the paper was written in. Any ranking system that ignores this is producing random noise or worse when applied to maths departments.
Comment: @DavidRicherby: Absolutely.  Nevertheless, such systems are used, and affect many mathematicians' career prospects.
Comment: I don't think linking to an undated document on some web server in a language that's not Korean provides sufficient evidence that this is how Korean universities evaluate their faculty's work in the context of pure math, where (as @DavidRicherby pointed out) this data would produce a completely nonsensical result. Your extraordinary claim that Korea and "many places in Asia" are bureaucratic to the point of insanity requires extraordinary evidence. I'll believe it when I see more convincing proof. Until then - downvoted.
Answer: The only "benefit" that I can think of of being the corresponding author - if you can call it a benefit - is that it prevents underhanded actions by coauthors. Sometimes, people from different groups and motivations, who are possibly at odds with each other, end up co-authoring. Or - an estranged pair of advisor-advisee. Some of the authors might suspect the others of being willing to compromise the paper somehow (obviously I'm being vague since this is inspecific.) The corresponding author, however, has control over communications with the venue, so s/he can exercise effective veto power over steps s/he disapproves of.
Comment: @MorganRodgers: Let us not speak of such atrocities :-(
Answer: To answer your questions in order, and based purely on my own experiences (in pure math in the UK).

Some reasons for choosing a particular person as corresponding author might be:

they are more experienced in dealing with journals
they are less experienced and so need the experience
they happen to be less busy at the time of submission
they are more junior and less busy in general
they are more senior and so their affiliation is unlikely to change (and they're not likely to leave academia)
they volunteered
it's their turn
they are the most organised
they know how to format the paper to the journal's requirements

The main "benefit" is being in control of the process. The non-benefit is that it is extra work - even if it doesn't make much difference to who actually implements any changes the journal asks for, you probably still end up emailing the other authors to say what needs done, writing the response to reviewers, checking proofs, and various other small things.
No. The reasons for being corresponding author or not are very varied, and either largely irrelevant or things that are more obvious from other factors anyway, so it's not useful information. IMO it would look very weird to specify on a CV which papers you were a corresponding author on, and I doubt any committee would bother to find this out. It would perhaps be preferable to have been corresponding author at least once, but in pure math people will generally have some single-author publications and so this isn't an issue.


Is it allowed to include graphs in a thesis without explicit permission?

Question: In a thesis, is it allowed to include graphs from other papers without an explicit permission from the publisher? (assuming citation is provided)
Comment: Related: https://academia.stackexchange.com/questions/40173/academic-fair-use-and-using-publication-images-in-your-thesis?rq=1
Comment: While this is pretty close to the old question, I think there's some benefit to this one. In particular, I think the "fair use" part is a little misleading, since there's a huge difference between legal standards and academic/university ones.
Answer: Depends on your university policies, but probably yes. There is probably a "thesis FAQ" at your graduate division that will clarify this!
I had to request permission for many separate aspects of my thesis, including sections of my own papers that were re-used, and (I think) figures from other peoples' papers.
Usually you can do this through the journal's "Request permissions" link, which takes you through Rightslink or something similar, and the cost was always zero for me. Other journals (PLOS) have explicit copyright policies which you can reference.
The risk here is that when you file your thesis, someone in the graduate division will say, "wait, this isn't from your work, do you have rights to do this?" and slow your graduation down! The only people who can tell you whether this will happen are at your university. For instance, this is a policy page for copyright at Michigan Tech: http://www.mtu.edu/gradschool/administration/academics/thesis-dissertation/copyright/use/
Answer: In USA and EU, the legal answer is yes, the Fair Use exemption for educational use should apply. (read: it clearly applies, but I am no lawyer.)
It's still pretty rude, though, so I asked for permission. I found peer-reviewed authors are pretty accommodating. Getting permission and citing appropriately removes any possible wrongdoing from inclusion.
My advice is: just ask for permission and you might also build some useful bridges in the process.


Upgrade SBS 2008 to SBS 2011

Question: I am migrating from SBS 2008 to SBS 2011 but the Microsoft documentation does not yet exist.
Has anyone done this yet?
What are the recommended steps/procedures?
Answer: Microsoft has now posted the documentation on how to do this
http://technet.microsoft.com/en-us/library/gg615506.aspx
Answer: SBS 2011 just released to manufacturing last month (it's not even on my Partner access yet) so it looks like there isn't a lot of third party posts about migrations. From the few that I have it looks to be similar to the migration from SBS 2003 to SBS 2008.
I think the only exception would be the migration from SBS 2008 to SBS 2011 Essentials which is a cloud based offering.
http://www.sbsfaq.com/?p=2351
http://blog.mpecsinc.ca/2010/12/sbs-2003-to-sbs-2011-microsoft.html
http://blogs.technet.com/b/sbs/archive/2010/12/13/windows-small-business-server-2011-standard-releases-to-manufacturing.aspx
SBS 2003 to SBS 2008 Guides:
http://blog.mpecsinc.ca/2009/06/sbs-2003-to-sbs-2008-migration-guide.html
http://technet.microsoft.com/en-us/library/sbs-2008-2003-migration(WS.10).aspx
Comment: I have it available in my technet subscription so I attempted to do a migration the same way I did from SBS 2003 to SBS 2008 but i ran into some errors so I am not sure if there is new steps I don't know about.
Answer: I did this a while back using the Microsoft method, there is details inside the SBS 2011 Administrators Companion that outline how to do it.
I must say, having followed it step by step, I did run in to a number of catastrophic errors so I would recommend building a test environment imaging your existing SBS 2008 server, restoring it to your test lab and trying it for real.

Upgrade SBS 2008 to SBS 2011


See calendar overlay in All Events view

Question: I have an overlay on a calendar and I am able to see the events in calendar view but not in the All Events list view. Is there a way for the overlay calendar to show in the All Events view? Or is the calendar view the only view that it works on?
Answer: Overlays are for the calendar views only. The AllEvents view is a standard list view and so will only show the items for the calendar list it is associated with.
If you want to combine multiple calendars in a list then you'll need to use either the Content by Query web part or the Content by Search web part.

See calendar overlay in All Events view


Recognizing numerical entities

Question: I'm trying to perform classification on a large dataset with mixed numerical and categorical features. The dataset is all semi-structured text, so everything is a String. Does anyone know of a library I could use to automatically identify numeric features (e.g. "width (in.)", which corresponds to the width in inches)? This is important because numeric and categorical features are encoded/handled differently in my analytics pipeline. I think this is basically a named entity recognition problem wherein the entity is a numeric variable or feature that exists in the data set as a String/text.
Comment: Depending on what your data looks like, you might be able to simply use the regular expression r'^\d+\s+?\(\S+\.\)$' (see http://rubular.com/r/ZS7vZaR3XD, for an interactive example). Can you post some example rows from your data?
Comment: it really is just a line of text with terms separated by a "<" symbol. Each term is a String and corresponds to a feature. The problem is that the number of terms per observation (line of text) is about 2K terms (Strings). Some of those are numeric features, e.g. "width (in.)", "Height (in.)", "Capacity" etc, while other terms (Strings) correspond to categorical feature, e.g. "connection type"..etc. If the number of terms per observation is small/manageable, I would just do this manually, but with 2K I think I should use some kind of NER for recognizing numeric features like measurements.
Comment: I should add that this is needed to avoid numeric features being treated as categorical by something like DictVectorizer() from sickit-learn which would make the data extremely wide and is basically a wrong way of encoding features.
Comment: Agreed. I suspect NER is overkill for the problem you're working on. You'll likely still have to manually annotate some amount of data to get a good approach working, and there some degree of error you'll have to buy into. From what you've described, it seems like regular expressions is the best approach here, but debugging those is easiest with some sample data.
Comment: I would do that with regex. Could you post some sample data? You can find numeric and non numeric patterns and look ahead and look behind with regex. For the second time please post some data. OK so then you are already able to extract the terms in the < > ?
Comment: I appreciate your help and caring enough to ask again. I can't post any data. However, if you read my comment above to Kyle, you'll know exactly what I'm asking. Or simply answer this: given a line of text consisting of terms separated by a known delimiter ('<'), you can get the individual terms with Split('<'). Then the question is HOW do you find out which of these text terms refer to a numeric feature, e.g. "width" and which refer to a categorical feature, e.g. "connection type". That's it.
Comment: i thought about that, but... this is NOT an unusual situation, quite the contrary. Many, if not most, machine learning problems have mixed type features, numerical and categorical. So my thinking is that sickit-learn, Spark's MLLib or similar ML libraries MUST have functionality to do this.. I seriously doubt people do this manually.
Comment: @Kai: I'm not sure what python/sklearn libraries there are for NER, but I suspect using Stanford NER is a good place to start: http://textminingonline.com/how-to-use-stanford-named-entity-recognizer-ner-in-python-nltk-and-other-programming-languages
Answer: There are many good libraries for identifying number-like values, but identifying corresponding fieldnames is trickier and likely very problem-specific.
A purely data driven approach might look for co-occurrences with numbers, for example:
if [*number-like* capacity] or [capacity: *number-like*] occurs in > x% of

the instances where "capacity" occurs,
    then "capacity" can be guessed to be a label of number-like things.
Even the nature of these relationships (eg, whether it should be before, after, capitalised) could be learnt from existing known labels.
This can be done with Google BigQuery using the public tri-gram sample data.  But I assume that's out of scope and impractical here.
A practical approach, might aim to classify these strings as numerical_units, categorical_units or unsure or even more classes, and then do human review of the latter.  (There are some very tricky cases, for example, "capacity" is numerical, but "capacity type" would not be.)
As a starting list you can use:
wiktionary:Category:en:Units_of_measure
wiktionary:Category:Symbols_for_SI_units
wiktionary:Category:en:Mathematics
Note that they are in the singular.  For your domain considering finding other such lists.
If a string is a full match with one of those labels, you can consider it a numerical_unit.
Your next concern is tolerant, fuzzy matching.  You could treat '.' as a wildcard (so "in*" matches "inch"), or find the actual abbreviations of units like "inch".  These you can label as unsure and then review.  Likewise if the word is simply contained in the string, eg "arch length" contains "length".
I think once you have done this you can make some refinements and add some special cases.  Without seeing even a sample of your data, it is difficult to say more.  If most of your strings are numerical units, then it may be easier to identify categorical units instead.
Comment: Ok, thanks for the details. Let me ask the question differently; machine learning is being applied to wide datasets (# of features is large, thousands or more). There MUST be standard tools, libraries etc that people use in order to distinguish between numeric and categorical features .. I doubt people are going through the data manually or even with regular expressions designating the type of each feature... this is an important step before applying your classifier, there's no escaping it, hence I think there must be existing tools to do this. IF not, what do Machine Learning Gurus do?
Comment: Yes, there are good standard tools for it, but they are based on input of feature values (many per field), not the arbitrary feature name.  If you do indeed have a list of such values (eg "4.2"...), then it's easy.  If the values are mixed (eg "4.2 in") then it's also solvable.  But in your examples you give strings that do not contain numbers but rather look like column names.  In same cases these could be written as "length_inches" or "leninches" or even "field 32" - much less solvable.
Comment: OK, so it appears that this step of recognizing numeric vs categorical is highly application dependent; if the problem space guarantees meaningful col names ("width") then we can use some NER API, otherwise you have to create some kind of algorithm that looks at the feature **values** to recognize feature type... there is no universal solution. Can you point me t these "standard tools" for recognizing feature type from feature values? as in the example you give where the feature value is a String: "4.2 in." ? I am inclined to write this myself now, but I still like to see existing solutions.
Comment: Pandas will do it.  I would preproc out the " in." though.

Recognizing numerical entities


What equipment/cords do I need to record a digital piano?

Question: I've been playing piano for about 6 years and I enjoy playing in front of an audience. Their are tons of youtuber's that put their music online and I would also like to. I just dont know what cords I need and the equipment I need to start. I know I'll need a camera to record the piano playing, and then 2 cords with those 4 holes prongs, and then a DAW. I bought a midi cord that connected to my piano, but when I replayed it, it sounded like the Synesthesia programs where its just sound and not the piano tone. I would like to shed some light on this topic. A crisp and clear piano recording accompanied by the video of me playing the piano would be the ideal goal. Links or videos would be greatly appreciated.
Comment: I answered a similar question on Stack Exchange a year ago.  Rather than repeat it as an answer here - just click on this link (http://music.stackexchange.com/a/30301/16897) to read about recording a digital piano to accompany a video of you playing it for YouTube.   It explains the advantage of simultaneous recording of the   output of your piano with your camera's video recorder and the direct output of your piano to your computer through an audio interface to facilitate merging the video with perfectly synchronized audio free of background noise.
Answer: Let's clear up a few things first.
You can record a digital piano in two ways:

Audio recording. This records the actual sound that the keyboard makes. To do this, you'll need to route one or two of the audio outputs of the keyboard to some sort of audio interface.
MIDI recording. This records the notes that you play in a digital format. It does not record any audio information. You can play it back using the same keyboard, and it will sound the same. But you could use a different playback device, and it will sound quite different.

So, to address your question, I think you want to use audio recording, but you are currently just recording MIDI. The good news is that audio recording is usually pretty simple to play around with.
First, you don't need MIDI cables (the round plugs with four prongs, technically called DIN connectors. You need some audio cables. Usually that will be a 1/4 inch jack, mono or stereo.
Then, you need an audio interface. You can buy a specialised one, but I'd recommend playing around with the microphone input on your computer. It might be a bit noisy, but you should try it out first. It'll help you get an idea of how this all works. You'll need a 1/4 inch to 1/8 adaptor or two.
Once it's plugged in, you'll need to record it. I'd recommend playing around with Audacity to start out with. It's free, simple, and will give you an idea of how this all works.
Once you've got a taste, you can spend some more cash to get some better equipment. But I'd recommend trying all this out on a cheap/free basis first.

As a variation, you could try and record the keyboard using the camera itself. Often a camera will have a microphone input. You could try using that.
If you want to record other audio simultaneously (you speaking, or something like that), this might not work. The microphone input will often disable the internal microphone.
Comment: Present laptops (mine being one) don't have an aux in or mic in. So, does it mean one has to use the USB o/p of the interface and connect to the USB port of laptop? Will that be an audio or midi signal?
Answer: If I were in your place, I wouldn't prefer using MIDI as suggested by @endorph because you might not get suitable plugins to satisfactorily replace your piano's sound. However, that's my issue. You can record the sound of a digital piano in any of the following ways:

Using a high quality microphone:  All you need is a high quality condenser/dynamic microphone and an audio interface. A condenser microphone is ideal for use in a sound proof environment whereas a dynamic mic would be the preferred tool in case you're recording in your bedroom. Both types of mics have their pros and cons. You can do some research and listen to recording samples to decide which one is the best for you. Should you choose to record with a mic, make sure that you have high quality output from your digital piano. You could also buy a separate speaker system/amplifier that will serve the purpose.
Connecting your digital piano directly to an audio interface: Your digital piano has an audio output (stereo I bet) line, doesn't it? You can simply connect the output channels to your audio interface to record the sound into the computer and then mixing and exporting it. This is suitable if the bare output you hear isn't good enough to be caught by a mic.

No matter which of the above ways you choose, you need an audio interface. Make sure to get a 2 channel USB audio interface. To name some would be:
     ♦ Presonus Audio box USB 2x2 interface
     ♦ Focusrite scarlett 2i2 interface


Nessus Vulnerability Scanner

Question: My question is: can we use Nessus to perform a scan on a remote server? Or is it used only to perform scans on the local network?
Answer: I am not sure what you mean "on a remote server" but very simply put: yes, you can - as long as you're authorized.
If your scenario is to scan server which lies outside of your local network (for example a different server belonging to your company, hosted somewhere else) Nessus is your choice.
If you mean you want to perform a scan from a remote server with Nessus, that's possible as well. Our company uses Nessus on a dedicated server for external scans.
But be warned - don't scan server which you're not authorized to.
I also believe trial version is only for non-commercial scans.
Happy scanning!
Comment: @JamalD Happy to help. Can you mark this thread as solved?
Comment: Using scanners with non-intrusive/destructive behaviour is not illegal (where i live), even if you do it without permission - as long as you do not harm/breach/intrude the system you are scanning.

Nessus Vulnerability Scanner


Bulgarian passport expires two months after return date, will I have a problem traveling from US through Germany to Bulgaria?

Question: I am flying from San Francisco to Bulgaria through Frankfurt and Munich in a few days. I hold a green card and I am a Bulgarian citizen. I just found out about the 3 month passport expiration date rule. My Bulgarian passport expires 2 months after return date. Since I am a EU citizen, does that rule apply?  Am I going to have problems passing through Germany or even in San Francisco? I was planning on renewing my passport in Bulgaria.
Answer: No, the rule does not apply to you and you can do this trip on your current passport.
The rule defined in the Schengen Borders Code is for third-country (i.e. not EU/EEA/Swiss) nationals. You are protected by the EU freedom of movement and only need a valid ID (not even necessarily a passport).
Incidentally, third-country nationals are generally required to have a travel document valid three months after the intended end of their stay in the Schengen area but that makes no sense for you as you have a right to stay in Bulgaria (or even in Germany, with a few caveats) as long as you like.
Answer: My wife (Bulgarian and US citizen) traveled from the US to Sofia via Frankfurt last year when her BG passport was already expired. In Frankfurt she used her US passport and in Bulgaria they accepted her expired passport along with a valid BG national identity card, no problems at all. She renewed her passport while in Bulgaria.


Two-sided vs One-sided p-value: is there a special case with Fisher's Exact test?

Question: I read [this] and I usually agree with the view that two-sided p-values are double of one-sided "greater" ones ("lesser" ones being 1-"greater").
But someone told me that "probability distribution of the tables with fixed marginal sums used in Fisher's exact test is not symmetric."
Is it right?
Answer: In general it's not symmetric, that's correct. I assume the 2x2 case is specifically intended here (beyond that the notion of tails is problematic).
The distribution of the count in (say) the top left cell is discrete and in general, asymmetric. Specifically, it has a hypergeometric distribution. For some particular two-tailed significance level, different fractions will be "in" each tail.
In some cases it will be symmetric, though. For example the distribution of the number of correct guesses in the experiment of the lady tasting tea is symmetric.
(In relation to the exact test, Fisher wasn't one for alternative hypotheses so such considerations as which tail had what wouldn't have been part of what he'd normally concern himself over, except in so far as it might help him arrive at the calculation of the p-value.)
Here's an example that's asymmetric, and where all the values in the critical region for a 5% test lie in one tail. This is for a table with row totals 15 and 60 and column totals 12 and 63, and where we consider the count in the top-left cell:

If we're in Neyman-Pearson mode (and being conservative with our significance level), you would work out your critical region by adding up from the smallest probabilities of the null distribution to the largest until you got as close as possible to $\alpha$ without exceeding it. We see that the left tail here would never be able to come in, because the lowest probability in the left tail is more than our $\alpha$ of $0.05$ (indeed, even if it was a fair bit smaller than 0.05 it wouldn't because it would still take the cumulative sum over 0.05). Clearly then, this would be a one-tailed case.
If we're in Fisher mode, we take our particular table and add in all tables with equal or smaller probability. If our table is in the right tail and its probability is below 0.05 all the smaller ones would be as well.
So that would also be a p-value where all our two-tailed contributions were from the one-tail.
Comment: @AndoJurai: There's more than one way of comparing the "extremeness" of tables in opposite tails - Glen_b's described what I think is the most common. Check the package documentation.
Comment: Quite possibly, it depends on the numbers. Why hide the details of the specific situation you want to know about? (Edit: actually, I have an example, I'll put one in my answer)
Comment: Thanks! Is there any way that a one-sided value could be equal to a two-sided value ? It seems to me illogical, but as I am not good enough and not sufficiently well-versed in these kind of stats, I prefer to check. Actually, my problem come that some package function yields values that seemed odd to me, so I need to check this before making any conclusions.
Comment: Thanks to both of you. I was not particularly hiding the details, just that before citing a package method as potentially broken, I preferred to check, it's more sort of having some courtesy/regards for package makers, actually, plus it was more a case that I encountered and wondered later about, so I had no data anymore readily available for putting as an example in the question.


Is this patent US6323569 B1 still valid? Valid till? End date?

Question: I would like to know is patent "US6323569 B1" still valid? its end date?
Answer: If you look in http://portal.uspto.gov/external/portal/pair (enter the number without the "US" and "B1") as "Patented case" and the next fee payment window closes on 11/27/2013. The patent is valid. You will also be able to see that it had quite a stormy path to its acceptance which resulted in a certificate of correction.
If the maintenance fee is paid, the patent will expire on 11/3/2019, 20 years after the effective filing date.
Comment: This answer was close but should have also noted that if the fee payment was missed, then the effective date for expiration would be November 27, 2013.
Answer: As of November 27, 2013, this patent had lapsed due to a Failure to Pay Maintenance Fee. As of January 14, 2014, US 6,323,569 is expired and is no longer enforceable, with an effective date of November 27, 2013.
<code>Nov 3, 1999 AS  Assignment

Dec 24, 2002    CC  Certificate of correction

May 5, 2005 FPAY    Fee payment
Year of fee payment: 4

Apr 29, 2009    FPAY    Fee payment
Year of fee payment: 8

Jul 5, 2013 REMI    Maintenance fee reminder mailed

Nov 27, 2013    LAPS    Lapse for failure to pay maintenance fees

Jan 14, 2014    FP  Expired due to failure to pay maintenance fee
Effective date: 20131127
</code>


Is there any reason to re-rack and wait another week after dry hopping before bottling?

Question: Is there any reason to re-rack and wait another week after dry hopping before bottling? The only reason I can think of is for settling of residual dry hopped particulates. But if you don't syphon those out, is there any reason to wait?
Answer: No, in fact the rewards almost certainly don't outweigh the risk of oxygen pickup (or contamination) from the rack. This is especially the case if you're not going to be performing a true secondary fermentation (i.e. bottle- or keg-conditioning). Even if you are, best to rack straight into the bottle or keg so that any ill effects of oxygen pickup will be mitigated by immediate yeast action.
If you're worried about hop particles (or anything, really), just leave it where it is for another week. I can think of almost no case where it's better to rack again than it is to just leave the beer where it is a bit longer.
Comment: I think it would be better to put a filter on the end of your racking cane. I use a bit of plastic mesh for window screens, held in place by a bit of wire.
Comment: FWIW I just bottled this today, off the dry hop. My only problem was sucking up hops into the bottling bucket, which then clogged my bottling wand. Next time I'll rerack at least for a few days to get the hops out.
Comment: I use a fine nylon mesh bag over my racking cane/syphon. Works well.


Lithium ion battery impact of cycles on discharge rate

Question: Basically all I've been able to read and find out until now is that the capacity of lithium ion batteries goes down with cycles. I'm currently programming an arduino to accurately estimate the State of Charge of a 58V+ Li-Ion battery. I've managed to obtain plots of cell capacity against cycles as well as discharge rates at different temperatures and current draws. I am wondering how that capacity reduction with cycles impacts the cells' discharge profile. Is it decreased by a factor so that it still is bounded by the same voltages (4.2V and 2.5V) but discharges more slowly. Or does the discharge rate stay relatively the same but the bounding voltages reduce in range? Or both?
Thank you for your help!
Answer: Unless you are short circuiting the battery discharge rate is dictated by the load connected rather than the battery cells themselves.
When a cells capacity has reduced the full and empty voltages remain the same, what changes is the maximum amount of charge stored within the cells. They will take less charge to reach the maximum charging voltage and so have less charge in them to discharge.
Also keep in mind that for Li-ions voltage is significantly impacted by temperature.
Answer: The voltage profile does not change , but the ESR rises radically as SoC drops below 10% and rises slowing with aging or cumulative charge cycles.
Restricting SoC range to 50~100% or preferably 50~75% when possible will extend useful cumulative life of amp-hours transferred, as modelled by Lenovo.
The useful range should be limited to 3.3V to reduce self heating.