Comments

Author Comment Last activity Moderation
gretchengehrke "Hi @cfastie, I'm not sure when EDGI's software website monitoring software will be available for public use (our developers are working really hard..." | Read more » about 2 years ago
gretchengehrke "That is such a good idea, @Ag8n!! We should definitely try this. @sara, what would you think about trying this with copper strips that are colocate..." | Read more » about 2 years ago
gretchengehrke "Also, I just saw on comptox.epa.gov that acetone is actually more hydrophilic than isopropanol, which totally surprises me! I guess vapor pressure ..." | Read more » about 2 years ago
gretchengehrke "Either acetone or 99% isopropanol are probably fine, and maybe we should do a comparison. The only concern I see with isopropanol is that it has a ..." | Read more » about 2 years ago
gretchengehrke "Hi @Ag8n, with regards to the medical situation vs equipment, it sounds like the particle sizes they are measuring are relevant for (1) respiratory..." | Read more » about 2 years ago
gretchengehrke "Hi @Ag8n, Do you know what gmp facilities (good management practices, in case others are unfamiliar with the abbreviation) use for the 0.5 micron s..." | Read more » about 2 years ago
gretchengehrke "Also, its interesting that cristobalite is rounded. I will look in the literature to see if there is a relationship between cristobalite and silico..." | Read more » over 2 years ago
gretchengehrke "I'm glad you brought this up, @Ag8n! @Mathew did some work with polarimetry too. See this research note: https://publiclab.org/notes/mathew/05-21-2..." | Read more » over 2 years ago
gretchengehrke "Thank you so much, @Ag8n! This is exactly what I was hoping to see. I live near Duke University and can see if they have the books there too. Does ..." | Read more » over 2 years ago
gretchengehrke "We've been trying to use DIY microscopes to distinguish between crystalline and non-crystalline particulate matter. Of course we wouldn't be able t..." | Read more » over 2 years ago
gretchengehrke "Hi @Ag8n, Do you know how the aquarium TDS meter works? Maybe it really is just a super cheap conductivity meter? " | Read more » over 2 years ago
gretchengehrke "Here's a great resource for soil sampling. Section 8.3.2 gives a good start for a step-by-step protocol for surface soil sampling. Table 8.2 is sup..." | Read more » over 2 years ago
gretchengehrke "Table 8.2 in that doc is particularly useful. " | Read more » over 2 years ago
gretchengehrke "Here is a great reference document that helps parse out some different types of sampling for different study designs, depths of samples, etc. We co..." | Read more » over 2 years ago
gretchengehrke "This one seems like it could be good if you were monitoring near somewhere with wireless: https://www.amazon.com/dp/B0013BKDO8/ref=asc_df_B0013BKDO..." | Read more » over 2 years ago
gretchengehrke "Agreed! " | Read more » over 2 years ago
gretchengehrke "Hi @warren, "miscible" means it dissolves with them to create a homogenous mixture (i.e. doesn't separate out like oil and water do). Acetone is a ..." | Read more » over 2 years ago
gretchengehrke "@Zengirl2, I think for the best results you'll want to use acetone, which is easy to find online and in a lot of drug stores and art stores (and ma..." | Read more » over 2 years ago
gretchengehrke "Yes! Pennsylvania is actually one of the few states that does have ambient air quality standards for hydrogen sulfide! Read more here: https://publ..." | Read more » over 2 years ago
gretchengehrke "Yes, OSHA does regulate workplace exposure to hydrogen sulfide. The OSHA "ceiling" exposure limit is 20 ppm, though NIOSH- the federal research ins..." | Read more » over 2 years ago
gretchengehrke "In the United States, hydrogen sulfide is not considered a "criteria pollutant" or a hazardous air pollutant. Thus, there are no federal ambient ai..." | Read more » over 2 years ago
gretchengehrke "This is so cool! Thanks Liz! " | Read more » over 2 years ago
gretchengehrke "Hi Stevie, in my experience, it really depends on what the end goals are (e.g. assessing general/chronic conditions or synopses of specific conditi..." | Read more » over 2 years ago
gretchengehrke "For regulatory purposes, the EPA doesn't actually measure the size of individual particles. Rather, they use a pump with an impactor. This pumps in..." | Read more » over 2 years ago