Wikipedia:Reference desk/Archives/Science/2016 April 9

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

April 9

Source of ammonia in life science lab?

What is a source of ammonia in a life science lab that might be used, for example, to clean an oven? --78.148.105.117 (talk) 13:13, 9 April 2016 (UTC)

I don't know why you need a life science lab. I can buy ammonia for cleaning at my local grocery store.--Jayron32 13:23, 9 April 2016 (UTC)

It is no longer sold in stores in the UK. 192.41.128.212 (talk) 18:54, 9 April 2016 (UTC)

Apparently true, but you can still get it from Amazon. Tevildo (talk) 19:42, 9 April 2016 (UTC)

From what I read at [1], the UK actually loosened restrictions on ammonia in 2014, even while putting up roadblocks to other chemicals. (further info if you're curious) Of course, any kind of optimism seems out of place with the modern UK, but I think a citation needed is still in order. Wnt (talk) 23:43, 9 April 2016 (UTC)

Well, I had a quick look at the websites of various major UK retailers. Tesco, Sainsbury's, Homebase, Wickes and The Range don't list it at all - B&Q lists it, but show it as being out of stock in all their stores. It may be possible to obtain it in a UK store, but it's certainly not easy. Tevildo (talk) 09:14, 10 April 2016 (UTC)

Are you asking what lab activities might incidentally create ammonia fumes in that lab ? If so, the obvious answer is cleaning, specifically with glass cleaners, which often contain ammonia. It's also possible that some experiment might create ammonia. StuRat (talk) 15:25, 9 April 2016 (UTC)

Chemicals in laboratories are purchased from any number of sources, such as Sigma-Aldrich. --OuroborosCobra (talk) 15:42, 9 April 2016 (UTC)

• This question is too unclear to answer. Ammonium hydroxide for most lab uses is highly concentrated and its fumes should NOT be inhaled. Using it to clean an oven would require substantial dilution in a well-ventilated area. Confusing the two could lead to severe injury, and I think it might also damage the oven (I don't know that). this source says 14-15 M for lab solution and 5% (NH3) for household; doing the calculation they suggest, I get 17 g/l is 1 M and so 50 g/l = about 3 M, or 5x diluted, but PLEASE DO NOT RELY ON THAT because neither source nor calculation is guaranteed here. Just buy your cleaner at the store, and do not fool with lab ammonia for anything but real chemistry. Wnt (talk) 16:42, 9 April 2016 (UTC)

What about solid ammonium bicarbonate? Ah, here we have solid ammonium chloride! Perfect! I heard I can just leave this to evaporate in the oven and do all the cleaning by magic 192.41.128.212 (talk) 18:54, 9 April 2016 (UTC)

• • Lab ammonia? Chemicals do not care what their destination is, they just are. Any lab is going to either order the proper concentration and purity for their specific use, or be able to dilute down from a concentrated source. If I do not need HPLC grade purity for whatever work I am doing, I do not spend the money on HPLC grade. I don't know of anything called "lab <insert chemical name here>." Nor would I order already diluted HCl for almost anything (unless I really really need 1.000N HCl), I have a supply of glacial that I dilute down to whatever I need for either experimental or cleaning usage. --OuroborosCobra (talk) 17:51, 9 April 2016 (UTC)

Handedness and cheek concavity

I am interested in finding reports of evidence either for or against the hypothesis that left-handedness is correlated with concavity of the right cheek (more than the left cheek), because of the right cheek being supported by the right hand while the left hand is writing; and vice versa. Where can I find such reports?
—Wavelength (talk) 18:46, 9 April 2016 (UTC)

In the Eurasian Journal of Anthropology Analysis of facial directional asymmetry in extreme handed young males and females concluded that handedness may affect the level of directional facial asymmetry but only that this may be caused by the asymmetrical development of the cerebral hemispheres, with no speculations about writing habit itself as the cause. AllBestFaith (talk) 20:29, 10 April 2016 (UTC)

Thank you for your answer, although I am still interested in information about facial asymmetry caused by writing habits. (The EJA document introduced me to skewness and kurtosis.)

—Wavelength (talk) 18:46, 11 April 2016 (UTC)

US college admission through standardized tests alone

Does any US college admit students through standardized tests alone, either for undergraduate or graduate studies? The list of standardized tests in the United States confirms that there are plenty of options to choose from. Doesn't any college trust those test enough? --Scicurious (talk) 18:55, 9 April 2016 (UTC)

unless this has changed recently, Harvard requires neither high school diploma nor standardized tests for admissions...and there are instances of Harvard admitting unusual but gifted people who have neither...68.48.241.158 (talk) 19:39, 9 April 2016 (UTC)

You got the question the other way round. I don't want colleges that won't require any standardized test, but colleges that are happy with standardized test alone.--Scicurious (talk) 20:54, 9 April 2016 (UTC)

You would turn down Harvard? ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:30, 9 April 2016 (UTC)

That's not the point. Where anyone applies or should apply, or turns down or whatever is a private issue.

The point is how much trust do colleges put on the reliability of those test. --Scicurious (talk) 22:15, 9 April 2016 (UTC)

You said, "I don't want colleges that won't require any standardized test." Therefore, you would reject Harvard. Unless you would make an exception. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:13, 9 April 2016 (UTC)

Come on, Bugs. He's not saying he would "reject" Harvard as a place to go, just that it's not an answer to the question. --Trovatore (talk) 23:16, 9 April 2016 (UTC)

Again, Bugs. That's not the point. Where anyone applies or should apply, or turns down or whatever is a private issue.

The point is how much trust do colleges put on the reliability of those test.Scicurious (talk) 23:39, 9 April 2016 (UTC)

Most that Harvard would accept without the standardized tests will probably have evidence of some other kind that their taking the tests is little more than a donation to the testing service -- that they would 'kill' the test if they took it, more than likely. They'll have participated in enough other things and taken exams or contests of a higher difficulty. It's not that the test is meaningless to Harvard; rather it's meaningless for some of its strongest applicants.4.35.219.219 (talk) 01:18, 13 April 2016 (UTC)

College admissions is not just about academic abilities. They also want people who are a good fit, have social skills, are members of a minority (for being used as a token proving how liberal is the college), are children of alumni, have multiple interests, are famous, have stinking rich parents, or are good athletes.Llaanngg (talk) 22:42, 9 April 2016 (UTC)

Back when I was applying to schools (this was a long time ago), if memory serves, it was possible to qualify for admission to the University of California by test scores alone. That would be the SAT plus the "achievement tests"; I don't know what they call them now so I don't know where to link you to, but the SAT was considered an aptitude test whereas the "achievement tests" were about material you had mastered.

Oh, I think you still had to meet the content requirements — so many years of this, a different number of years of the other thing — but I believe the GPA requirement was waived.

There was an extra bonus. At the time, you didn't apply to individual UC campuses. You applied to the UC as a whole, and listed the campuses you wanted to go to, but they were allowed to offer you admission but specify a campus different from the one you wanted. There were eight campuses at the time, not counting UC San Francisco which was more specialized, and I think two or three of them were competitive (probably at least Berkeley and UCLA) in the sense that there were students who preferred those schools, and who would be offered admission to UC, but not to the campus they wanted.

However, if you qualified by test scores alone, you were guaranteed admission to Berkeley if it was your choice. At least that's what the representative from UC told me. I never saw it written down anywhere. So Berkeley wound up being my "safety school"; I didn't get a good feel from the campus and didn't really want to go there, but it was good to have a backup. It has gotten much more competitive in intervening years. --Trovatore (talk) 23:05, 9 April 2016 (UTC)

Actually, it's filtering back to me that maybe you did apply to your first-choice campus directly, maybe listing your other choices in order of preference. The catch was that you were only allowed to apply to one campus. If you met the admission requirements, but your first-choice campus had more applicants meeting the requirements than they could accommodate, they would offer you admission to a different campus. So kind of the same in effect as what I said, but different in terms of where your application was physically sent and processed. --Trovatore (talk) 23:28, 9 April 2016 (UTC)

(This is really more of an RDH question but...) "Automatic admission" seems to be a big deal in Texas. Florida International University list GPA and test scores that can automatically admit an applicant, though it's unclear if you need one or both. Ditto for Louisiana State University. Google around some more for "automatic admissions" and you'll likely find a few other places. Do keep in mind that your state of residence is very, very important for any question pertaining to being admitted to or paying for a public university in the United States. Texas, at least, seems to only "automatically admit" students who are domiciled in Texas.

There are also likely to be some schools outside your state to which you could be admitted based on test scores alone, but for which you would wind up paying a lot more than you would going to an in-state public university (which, at least in most places, you have a better chance of being admitted to than as an out-of-state applicant elsewhere, even if your record is average-to-poor). This was actually quite similar to my situation when applying for undergrad admission: I had what I thought was a mediocre (homeschool) high school education, with notable highlights taking actual college courses, and wound up being admitted to two Public Ivys and the majority of the smaller liberal arts colleges I applied to. Like an idiot, I enrolled at the out-of-state Public Ivy and wound up paying triple what I could have paid in-state. If you're asking because you or someone you know is applying, you really owe it to yourself to give it a shot, think about finances, and not limit yourself based on your expectations. Every admissions department weighs the various criteria differently. Evan ^{(talk|contribs)} 03:41, 10 April 2016 (UTC)

The University of California used to have a legal mandate (maybe it still does, I'm not sure) to admit a certain top percentage of all California students. The practical result was that if you had a certain minimum SAT score, you would be guaranteed admission to at least one of the schools in the UC system. — Preceding unsigned comment added by 108.16.82.233 (talk) 11:34, 10 April 2016 (UTC)

• The State of North Carolina will admit, to one of the schools of the University of North Carolina system, every North Carolina resident who has graduated an accredited North Carolina High School with a "college preperatory" diploma. Now, that doesn't mean all 17 of them would accept the applicant, merely that one is required to take them. --Jayron32 22:56, 10 April 2016 (UTC)

That's an odd system, especially since the admissions departments of the 17 constituent universities are, in theory, completely separate entities. I wonder how "college preparatory diploma" is defined, also. Evan ^{(talk|contribs)} 23:40, 11 April 2016 (UTC)

The state of North Carolina offers two high school diplomas. One is called the "Future Ready Core Course of Study", though before 2011 or so it was called the "College Preparatory Diploma" The other is called the "Future Ready Occupational Course of Study", and used to be called the "Occupational Diploma". The two diplomas are based on the idea that a student taking the Core Course of Study is going on to further education, and that students taking the Occupational Course of Study will be entering the workforce immediately after school. The CCS diploma is based on the minimum HS course requirements for the either the UNC system or the North Carolina community college system (the main difference being that the state 4-year Universities require two credits of a foreign language. The Community Colleges do not). Here are the requirements for each diploma. --Jayron32 19:27, 12 April 2016 (UTC)

• I got admission and a full scholarship to a prestigious undergrad school based on a standardized national test, but it did include writing an essay in addition, and I had to provide ID, my HS diploma, and prove I had gotten my shots. μηδείς (talk) 21:07, 12 April 2016 (UTC)