Volume of Abstracts - Università degli Studi di Milano

5 th Int. Workshop on Ice Caves (IWIC – V)
Barzio (LC), Valsassina, Grigna and Milano, September 16 – 23, 2012
Volume of Abstracts
considered useful indicators of warm/wet conditions outside the cave, time
when biogenic-derived CO2-rich waters seeped into the cave.
Future work on these carbonate precipitates may shed light on the
relationship between the oxygen isotope values in the ice layers and
ikaite‟s temperature-restricted field of formation. The aim of this study is
1) to infer the δ 18 O from hydration water of ikaite and cross-calibrate it
against the δ 18 O obtained from ice layers that contain ikaite and 2) better
understand the precipitation of ikaite and its transformation into anhydrous
carbonate. The results can serve as basis to further explore other
paleoclimatic and paleoenvironmental implications the presence of ikaite in
perennial ice cave accumulations might have.
WHAT CAUSED THE LEDS IN CAVE LIGHTING?
Novomeský J. 1
1 COMLUX sro – lighting studio, SK–82104 Bratislava, Kopanice 5, Slovakia (COMLUX@COMLUX.SK)
The LED are suitable for use in cave lighting equipments (CLE) since about
5 years. But some of the newest CLE do not perform as well as expected
for these modern lamps. It seems that many planers and users don‟t have
enough technical and practical knowledge and experience about it and its
application. Some new, no properly designed LED CLE, produce too much
or not enough light in the cave, cause quite strange unnatural colors and
the feeling of space deformation. And in the worst case help to intensive
grow of lamp flora.
To avoid some of the mistakes that can happen from improper use of this
new light source, experimentation with possible LED white light colors and
comparison with previous incandescent lamps found, that there is
necessary to suit the color temperature of used LED with the main color of
cave walls, to use only LED of the best quality with efficiency of more than
50 lm/W and color rendering index better than 80. Further is to avoid any
violent experiments with the light effects and to install the properly
quantity light into the cave. Only on this way is it possible to guarantee the
best visual impression for the visitors and good cave protection.
White LED have already reached luminous efficacies of 100-150 lm/W and
a color rendering index of 80. Target value for warm white LED in the next
10 years are more than 200 lm/W efficacy and a CRI of over 90. They are
immediately switchable, dimmable and have the technical life 30000-50000
hours mostly limited only through the drivers life. We don‟t need more life
in the usual lighting installations. It is more than 10 service years by the
3000 burning hours in a year. And what kind of lamp will we use after 10
years? They are 10 times better than incandescent and halogen lamps and
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