Forensics C

18alia
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Re: Forensics C

Postby 18alia » January 8th, 2017, 3:33 pm

Hi guys, does anyone have the results for reacting powders with NaOH? It's not on the wiki, and we don't have the resources to run the tests ourselves.

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Re: Forensics C

Postby Lumitailz » January 8th, 2017, 8:04 pm

Hi guys, does anyone have the results for reacting powders with NaOH? It's not on the wiki, and we don't have the resources to run the tests ourselves.
I'm pretty sure it precipitates with all the calcium and magnesium salts, and reacts with ammonium salts to form NH3

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Re: Forensics C

Postby sciduck » January 15th, 2017, 8:15 am

What is the percentage distribution for fingerprints? Some test keys say 70% loops, 25% whorls, and 5% arches while others say 65% loops, 30% whorls, and 5% arches.
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Re: Forensics C

Postby Magikarpmaster629 » January 15th, 2017, 9:47 am

What is the percentage distribution for fingerprints? Some test keys say 70% loops, 25% whorls, and 5% arches while others say 65% loops, 30% whorls, and 5% arches.
I see the first one more often I think
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Re: Forensics C

Postby 18alia » January 23rd, 2017, 11:42 am

Does anyone have the density values for different NaCl solutions? The only one I could find was 10%, and according to the wiki, 25% and saturated are often available for density tests.

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Re: Forensics C

Postby Lumitailz » January 27th, 2017, 5:31 pm

Does anyone have any idea how to identify a substance given a random mass spec graph? There are just so many possibilities and I am stumped.

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Re: Forensics C

Postby 19sawickin » January 31st, 2017, 3:47 pm

I'm not sure if this has been discussed at all on previous pages, but can anybody explain to me, or perhaps direct me in the right direction to find quality information about entomology involved in forensics as well as stages of death? Thanks.

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Re: Forensics C

Postby pikachu4919 » January 31st, 2017, 6:33 pm

Does anyone have the density values for different NaCl solutions? The only one I could find was 10%, and according to the wiki, 25% and saturated are often available for density tests.
10% - 1.07 g/cm^3
25% - 1.19 g/cm^3
saturated - 1.25 g/cm^3

**disclaimer: only if they're made correctly**

Screw sig figs this time despite that chem cares about them :twisted:
Does anyone have any idea how to identify a substance given a random mass spec graph? There are just so many possibilities and I am stumped.
Look for peaks at molar masses of known important components of certain components that substances can separate into when shot through the mass spectrometer (i.e. water, methane, benzene (?), etc)
I'm not sure if this has been discussed at all on previous pages, but can anybody explain to me, or perhaps direct me in the right direction to find quality information about entomology involved in forensics as well as stages of death? Thanks.
Ento in Forensics is mainly used to determine the amount of time that has elapsed between the death of the body and when it was found, which is then calculated via knowledge of the life cycle of the insect that was found on the body. As for stages of death, AsapSCIENCE explains it pretty well here: https://www.youtube.com/watch?v=55j-nVwHa_c
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Re: Forensics C

Postby daydreamer0023 » February 3rd, 2017, 11:56 am

Okay, sketchy stupid question here, do you know if bacterial inoculation loops can be cleaned safely with HCl to prevent sodium contamination without corroding the wire? We're probably going to use them for competition... :/
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Re: Forensics C

Postby raxu » February 4th, 2017, 7:54 pm

Hello!
Our team don't have access to access to the fibers... What does "shrivels" look like?

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