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Hi Feldhaus

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From the Hand Sanitizer section: "Alcohol rub sanitizers containing 70% alcohol kill 3.5 log10 (99.9%) of the bacteria on hands 30 seconds after application and 4 to 5 log10 (99.99 to 99.999%) of the bacteria on hands 1 minute after application." "3.5 log10" and "4 to 5 log10" are nonsensical. log10(x) is a function of x whereby the inverse function is 10^x. I'm not sure what the original writer meant here by simply writing "log10". To express, for example, 99.9% in a similar format one would have to specify "1 - 10-3". Doing so, however, adds no useful information to the simpler expression in its percentage form. Am I missing something?

You were not missing something.

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Microbiologist use the terms 3.5 log to the base ten and 4 to 5 log to the base 10 to illustrate and count the numbers of microorganisms they are dealing with. It is much easier to work with logs than to write out 5,000 or 10,000 or 100,000 every time you are talking about numbers of microorganisms. Microorganisms (bacteria) replicate by binary fission so log to the base 2 is converted to log to the base ten for convenience. For most people the use of logarithmic numbers is meaningless so the 3.5 log to the base 10 in the article was converted to 99.9% and the 4 and 5 log to the base ten was converted to 99.99% and 99.999%. For most people percents have more meaning than logarithmic numbers. Maybe we should remove the logarithmic numbers from the article and just use percents? What do you think we should do?--JSHibbard (talk) 21:14, 21 March 2009 (UTC)[reply]

Welcome!

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Some cookies to welcome you!

Welcome to Wikipedia, Feldhaus! I am Fetchcomms and have been editing Wikipedia for quite some time. I just wanted to say hi and welcome you to Wikipedia! If you have any questions, feel free to leave me a message on my talk page or by typing {{helpme}} at the bottom of this page. I love to help new users, so don't be afraid to leave a message! I hope you like the place and decide to stay. Here are some pages that you might find helpful:

I hope you enjoy editing here and being a Wikipedian! Oh yeah, I almost forgot, when you post on talk pages you should sign your name on talk pages using four tildes (~~~~); that should automatically produce your username and the date after your post. If you need help, check out Wikipedia:Questions, ask me on my talk page, or place {{helpme}} on your talk page and ask your question there. Again, welcome!

 fetchcomms 22:42, 25 November 2009 (UTC)[reply]