12 more posts in this thread. [Missing image file: vanillin.png]
For those who've dealt with Vanillin + NaBH4 reaction:
So I've got the vanillin/ethanol and BH4/NaOH solutions mixed together, and will add HCl until it's acidic. Then I plan on ice bathing this to get a precipitate of the vanillyl alcohol.
Looking at some online procedures and a video, this is as far as they go, but one or two others take this precip and do a ethanol heating/evap process to it. So for those who have experience with this, is that really needed (or in other words, did you do that)?
26 more posts in this thread. [Missing image file: pythonlol.jpg]
Hey, /sci/, I'm in a basic programming class for python, and I'm having trouble understanding the in-class assignment that was given today. Could anyone help me out? The problem is as follows:
A prime number is a number that is only evenly divisible by itself and 1. For example, the
number 5 is prime because it can only be evenly divided by 1 and 5. The number 6, however, is not prime because it can be divided evenly by 1, 2, 3, and 6.
Write a Boolean function named is_prime which takes an integer as an argument and
returns True if the argument is a prime number, or False otherwise. Use the function in a program that prompts the user to enter a number and then displays a message indicating whether the number is prime.
We're working in python 3.2
Studies and standards for judging them
6 more posts in this thread. [Missing image file: bieber overalls harper.jpg]
From reading various places on the net, people often criticize studies for different reasons. The things I've picked up on are:
If it's an experiment make sure the experiment is:
* controlled (have two groups: some subjects who get a treatment and some subjects who don't)
* randomized (subjects are randomly put in either treatment and control group)
* double blind (experimenters don't know which group subjects are in)
make sure the sample is:
* representative of the wider population (e.g. not American college students, since they stand out from the wider American population: higher IQ, etc.)
* large (i don't know when a sample size becomes large, i guess it's sort of arbitrary?)
1) What other things are there to judge a study by?
2) What percentage of social science/psychology studies actually fit these and other conditions to be considered "rigorous?" (e.g. the samples might not be very representative. According to this (http://scienceblogs.com/pharyngula/2013/03/01/we-are-the-weird/) most samples are Western, many of them American, and “67% of the American samples (and 80% of the samples from other countries) were composed solely of undergraduates in psychology courses”)
10 more posts in this thread. [Missing image file: 1360995293213.jpg]
Hey /sci/entists, I am having trouble with this question can you please help me
Find both unit direction vectors for the same line?
I have 2 points on the line (2,-3,-1) and (8,-1,2), how do I do this question?