Global Change Abstracts The Swiss Contribution - SCNAT

202 Global Change Abstracts – The Swiss Contribution | General Topics
08.1-435
New concepts of Be-10 AMS at low energies
Grajcar M, Döbeli M, Kubik P W, Synal H A,
Wacker L, Suter M
Switzerland
Instruments & Instrumentation , Engineering ,
Paleontology , Geochemistry & Geophysics
Isotopic ratios of Be-10/Be-9 with a background
sensitivity of 2 x 10 (-14) can now be measured
with the 0.6 MV Tandem accelerator of PST /ETH
Zürich using BeF2 instead of BeO as sample material
and injecting BeF- to suppress the boron
detector count rate. A new, high-resolution gas
ionization detector with a thin silicon nitride
entrance window and special preamplifier design
are essential in order to achieve this sensitivity. A
particle transmission of 50% is possible for charge
state 1+. Due to the maximum count rate that
can be accepted by the detector the BeF- currents
are limited to a few hundred nA. Measurements
of Be-10 in rainwater samples performed under
these conditions at the low terminal voltage of
0.6 MV with the new compact AMS system show
good agreement with results using the conventional
Be-10 measurement setup on the 6 MV facility.
Thus, this type of small scale equipment can
now also be applied for Be-10 AMS as long as Be-10/
Be-9 ratios are sufficiently high and measurement
time is not a limiting factor. Instead, using BeO
and the degrader foil technique with a silicon
nitride membrane the boron count rate can also
be suppressed sufficiently but the Be-10/Be-9 background
level is limited to 10 (-13) by scattered Be-9
and the overall transmission is less than 5%.
Nuclear Instruments Methods in Physics Research
Section B Beam Interactions with Materials and
Atoms, 2007, V259, N1, JUN, pp 173-177.
08.1-436
Terrestrial ecotoxicity and effect factors of
metals in life cycle assessment (LCA)
Haye S, Slaveykova V I, Payet J
Switzerland
Ecology , Agriculture, Soil Sciences , Toxicology
Life cycle impact assessment aims to translate the
amounts of substance emitted during the life cycle
of a product into a potential impact on the environment,
which includes terrestrial ecosystems.
This work suggests some possible improvements in
assessing the toxicity of metals on soil ecosystems
in life cycle assessment (LCA). The current available
data on soil ecotoxicity allow one to calculate the
chronic terrestrial HC50(EC50) (hazardous concentration
affecting 50% of the species at their EC50
level, i.e. the level where 50% of the individuals of
the species are affected) of nine metals and metal-
loids (As(III) or (V), Be(II), Cr(III) or (VI), Sb(III) or (V),
Pb(II), Cu(II), Zn(II) and Ni(II)). Contrarily to what is
generally advised in LCIA, the terrestrial HC50 of
metals shall not be extrapolated from the aquatic
HC50, using the Equilibrium Partitioning method
since the partition coefficient (Kd) of metals is
highly variable. The experimental ecotoxicology
generally uses metallic salts to contaminate artificial
soils but the comparison of the EC50 or NOEC
obtained for the same metal with different salts
reveals that the kind of salt used insignificantly
influences these values. In contrast, depending
on the metallic fraction of concern, the EC50 may
vary, as for cadmium: the EC50 of Folsotnia candida,
expressed as free Cd in pore water is almost
2.5 orders of magnitude lower than that expressed
as total metal. A similar result is obtained with
Eisenia fetida, confirming the importance of metals
speciation in assessing their impact on soils.
By ranking the metals according to the difference
between their terrestrial and aquatic HC50 values,
two groups are distinguished, which match the
hard soft acids and bases (HSAB) concept. This allows
to estimate their affinity for soil components
and potential toxicity according to their chemical
characteristics.
Chemosphere, 2007, V68, N8, JUL, pp 1489-1496.
08.1-437
Challenges for forestry and forest research
- How to promote effective cooperation between
science and practice?
Jäger J, Pluess A, Klank C, Ghazoul J
Canada, Switzerland
Forestry , Plant Sciences , Social Sciences
Wie vielerorts steht in der Schweiz das Waldmanagement
angesichts des Klimawandels und
gesellschaftlicher Änderungen vor großen Herausforderungen.
Die verschiedenen Ansprüche an
den Wald wie rentable Holznutzung, Risikominderung,
Freizeit oder Erhaltung der Biodiversität
bergen ein Konfliktpotenzial. Wie können und
sollen Forstwirtschaft und forstliche Forschung
die Probleme angehen?
Gaia Ecological Perspectives For Science and Society,
2007, V16, N4, pp 261-266.
08.1-438
Environmental impacts of conventional and
sustainable investment funds compared using
input-output life-cycle assessment
Köllner T, Suh S, Weber O, Moser C, Scholz R W
Switzerland
Modelling , Economics , Ecology
This study compares equity funds that are managed
according to sustainability goals with con-