The measurement of residual salt: a thought piece!

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Session 6 - Equipment and Products (Topic 6-5)
Dr John C Bullas
Road Surface Characteristics - Wayman Experts
Dr Gavin D J Harper
Energy Development Manager, Birmingham Energy Institute,
University of Birmingham
MEASURING RESIDUAL SALT AT ROAD
SPEED…."THE MAMMOTH IN THE ROOM"

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Distance from road (cm) plotted against soil salinity (NigFhloinn, 2011 [4]).

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Annual Indirect Cost for 500,000 tonnes of salt.
Figure reproduced from Burtwell, Jordan & Ofori-Darko (2004) [6].

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Say hello to Henry & James….
the most accurate tools we probably
have for measuring
residual salt!
But the LEAST practical needing
road closures!
…and yes, they SUCK
big time….

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But now say “Hello!” to
Scientists Roger Y. Tsien,
Osamu Shimomura, and
Martin Chalfie……
…..awarded the 2008 Nobel
Prize in Chemistry for their
discovery and development
of the green fluorescent
protein (GFP)

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Now it might just be GFP, or
one of its derivatives, that
provides US with a more
practical use for fluorescence
than in producing Alba the
fluorescent rabbit.
[n.b. remember existing
fluorescence based salinity
measurement methods may
get false positives]

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Do you remember
biology classes: sodium
ions get moved around
in fishes as a matter of
course!
Proteins bind to sodium
to prevent your menu
choices from getting
less salty or more salty
depending where it
lives!

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And, believe it or not certain
organisms will ONLY grow in
highly saline environments:
Wallemia Ichthyophaga, a
fungus which requires 1.5 M
NaCl (a concentration of 87.66
g NaCl/l) and it thrives even in
saturated NaCl solution.
What turns the growth on/off?
By Anticiklon - Own work, CC BY-SA 3.0,
https://commons.wikimedia.org/w/index.php?curid=27792453

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So we have:
-a proven and widely used source of
fluorescent protein away from
“natural” fluorescence,
-an organism or two that will only
grow in hyper-saline environments,
natural “switches” to control growth
-proteins known to bind to sodium
to keep the prize at the funfair alive
just that bit longer………

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Given we can also design proteins that “turn on” the their
fluorescence in the presence of certain ions………
From: Christoph Greb, Dr.
"Photoactivatable, photoconvertible,
and photoswitchable Fluorescent
Proteins", May 04, 2017,
Leica Microsystems
GCaMP is a genetically encoded calcium indicator,
or GECI initially developed by Junichi Nakai.
GCaMP is created from a fusion of green fluorescent
protein (GFP), calmodulin, and M13, a peptide
sequence from myosin light chain kinase.

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We now know the work
the lab needs to do:
Develop the NaCl tagging
“biome”
Develop the detection
method
Develop the bio-
manufacturing process
Develop the salt dosing
methodology

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And we also need to ensure:
The product is benign (unlike molasses)
so we don’t feed or kill anything
No false positives, decaying over a
short time to ensure only product + salt
is detected
Compatibility with dry, pre-wetted and
brine deicing technologies and not
masking the effect of salt on freezing
Relatively low-tech, robust and reliable
detection methods (no “nasty” lasers)

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Some have big reservations about releasing bioengineered
products into the wild………
But this is not going to be something that can reproduce!
AND it will require due diligence and government
approval in its development

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Any Questions?
[We might not be the best people to provide the
answers though, but we are keen to try]

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Thank you for your attention
DR JOHN C BULLAS:
johnb@waymanexperts.com /
john.bullas@gmail.com
DR GAVIN D. J. HARPER:
g.d.j.harper@bham.ac.uk /
gavindavidjamesharper@gmail.com