Biomedical Engineering Reference
In-Depth Information
van
Broekhuizen
et al. (2011)
Drilling
Silica
No
PNC, NAPD, SA
(10-300 nm)
Measurements were carried out during drilling in conventional
concrete as well as in a wall that was constructed with
NanoCrete mortar. For drilling in cured NanoCrete concrete
the arithmetic mean NP concentration for the down wind
position exceeds the concentration in the up-wind position by
40,000 #/cm³. For drilling in “normal” concrete this difference
is ca. 16,000 #/cm³
The median values for these situations differ by 20,000 #/cm³
and 6,000 #/cm³, respectively. The NPs emission generated by
drilling in NanoCrete concrete is 2-3 times higher than the
emission of drilling in “traditional” concrete, suggesting a
higher release of NPs from the NanoCrete concrete. However,
the emission of NPs from the idle-running drill indicates that
the higher emission during the NanoCrete-concrete drilling
may as well be caused by engine-generated NPs from the
higher drilling intensity in the denser NanoCrete concrete
Methner et al.
(2012)
Wet saw cutting,
grinding, hand
sawing
CNF
(composites)
Yes, free ibers,
bundles, and
agglomerates
PNC (20 nm to
1,000 nm) PSD
of fragments
(by TEM)
Wet cutting and hand sanding of CNF composite without
control revealed the highest particle number concentrations in
the breathing zone
Schlagenhauf
et al. (2012)
Abrasion
CNT (epoxy/
CNT
composite)
Yes, free-standing
CNTs and
agglomerates
were emitted
during abrasion
PSD
The mode corresponding to the smallest particle sizes of
300−400 nm showed a trend of increasing size with increasing
nanoiller content. The three measured modes, with particle
sizes from 0.6 to 2.5 μm, were similar for all samples. The
measured particle concentrations were between 8,000 and
20,000 #/cm
3
for measurements with the SMPS and between
1,000 and 3,000 #/cm
3
for measurements with the APS.
Imaging by TEM revealed that free-standing individual CNTs
and agglomerates were emitted during abrasion
(
Continued
)
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