Petrographer at Braun Intertec specializing in evaluations of concrete, mortar, soil and aggregate via optical microscopy, XRD, FTIR and chemistry
MN
Joined March 2010
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Jamison Langdon retweeted
We need to make the financial system work for every American.
Donald Trump has rolled back critical protections designed to prevent another collapse like we saw in 2008.
I won’t let him get away with it. mikebloom.bg/2SVDE4k
Jamison Langdon retweeted
Stop me if you’ve heard this before.
Trump promised not to touch Social Security or Medicare and Medicaid.
Well, he lied.
When I’m in the White House, I will keep my word to seniors and to the American people.
Jamison Langdon retweeted
In honor of #PresidentsDay, let’s take a look at what it means to be president.
Or rather, what it used to mean.
Jamison Langdon retweeted
Trump says he created the greatest economy of all time.
Turns out, it ranks 6th out of the last 10 presidential terms.
Either he’s lying, or he doesn’t know what he’s talking about. Maybe it’s both? bit.ly/2SBjzkY
#Quartzite, specifically #SiouxQuartzite as viewed through the petrographic microscope. The material on the right can be carved with a sharp implement.
#PortlandCement v #FlyAsh as observed in a mount under various lighting with a polarized light #microscope. @BraunIntertec #TheScienceYouBuildOn
#AggregatePetrography, ASTM #C295, can tell you a lot about a source material. In this sample, numerous #Slickensides are present which you can readily see when it is rocked back and forth. #TheScienceYouBuildOn @BraunIntertec
The reaction of #PortlandCement & #Water yields #CSH and #Portlandite [Ca(OH)2]. These rxns aren’t instantaneous & they take time to develop. Portlandite shows up around final set (around 6 hrs). See XRD scans below. #TheScienceYouBuildOn @BraunIntertec
Heard of the #MN_Filter? It's a blend of iron particles (yellow —>/lower image) & natural sand, used around #wetlands to reduce chem run-off. Main target is P, to ⬇️ algal bloom. We provide 3rd party eval of the Fe-enhanced particle content. #TheScienceYouBuildOn @BraunIntertec
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Jamison Langdon retweeted
Be proud, #Badgers — #UWMadison rose to the 25th best university in the world, according to the Center for World University Rankings. #OnWisconsin!
📈 go.wisc.edu/o12892
It is common to see #BleedWaterVoids present in #Concrete that has been troweled early or a little too aggressively, sealing the surface off so water cannot exit the concrete. Eventually it will get out but void spaces are left behind. #TheScienceYouBuildOn @BraunIntertec
Just for fun, in case you wanted to know what 100 yrs old hydrated #cement paste looks like, it looks like this. Strong amber colors are very typical. White arrows point to several large portland cement grains in the field of view. #TheScienceYouBuildOn
@BraunIntertec
#Isotropy/#Anisotropy is one of the more powerful diagnostic tools in optical #microscopy. Here we have #Microcline, with a cross-hatch pattern in XPL, you pretty much know instantly its microcline (flesh color of the rock is also a good indicator as well). #AggregatePetrography
Jamison Langdon retweeted
What truly makes our country great is its diversity. I’ve seen that beauty in so many ways over the years. Whether we are born here or seek refuge here, there’s a place for us all. We must remember it’s not my America or your America. It’s our America.
Ah, #Chert, the #rock everyone wants to show me. Is it a #PreciousStone? No, it’s pretty common but it is precious to me. In XPL is where it gets interesting, creating a kaleidoscope of cryptocrystalline quartz, along with silt-sized #quartz (—>) floating in the #SiliceousOoze.
Differential #carbonation at depth in #concrete. Yellow —>’s point to carbonated #paste, black to non-carbonated. Note the carbonation points in the lower XPL image. @BraunIntertec #TheScienceYouBuildOn #ConcretePetrography
#Carbonation of hydrated cement paste can be quite complicated, best evaluated in #ThinSection where the carbonation front is better understood than from application of a pH stain on a fresh fracture, saw cut section, or polished section. #TheScienceYouBuildOn #ConcretePetro
