September
2000, Amsterdam  Projects
 Latvia

Antons Maslovskis (17)
School: Rezekne Secondary School N6
Hobbies: reading books, listening to music
Career intention: Chemist
Email: antonsmav@mail.lv

The
use of vegetable dyes as indicators
Colourless acid and base solutions can be distinguished
with the help of indicators as litmus, methyl orange, phenolphthalein
and the universal indicator, which are commonly used at schools.
We decided to learn which of the plants common in our area could
also be used as acidalkali indicators. So we did research on
different acid and base theories and learned that the colour
of a substance depends on the structure of its molecules. We
continued this study with some practical work. Of the first
32 plants that were tested, the colours of the solutions were
transferred on to paper in watercolours. Later we prepared alcoholic
extracts from plants and observed colour changes of each dye
in five solutions with different pH values. With this,another
10 plants were tested .

Verza Andrejs (17)
School: Valmiera Pargauja gymnasium
Hobbies: Computer sciences, low level and hardware programming,
sightseeing, science exhibitions, EU activities
Career intention: Programmer
Email: int21h@mauer.lv

"Smart Graphs" program, a graphic method of problem solving
Nowadays, many methods, schemes and theorems are used for
solving mathematical problems at middle and high school. All
these methods and theorems are very specific and require indepth
knowledge of mathematics. If a more attractive method of solving
mathematical problems at school could be discovered, this could
mean that problemsolving would become more popular and it could
considerably make the teaching of mathematics and other exact
sciences more attractive. Looking for this fast, universal and
accurate method for solving a wide range of mathematical problems,
I started doing research on the graphic method. Of course, this
method still has some disadvantages (low performance, inaccuracy),
but to eliminate these disadvantages special software has been
developed. The software was also tested by students and their
recommendations were taken into account. The use of this method
together with the newly developed software is a leap forward
in teaching mathematics and other exact sciences at school.
http://www.lanet.lv/info/intermat/prg/p166.htm .

Austra Zarina (18)
School: Riga State gymnasium
Hobbies: reading science literature, painting and visiting
art galleries
Career intention: chemist or mathematician 
The
effect of cooling on the visible spectra of gemstones
I had an opportunity to work in a laboratory where gemstones
are tested. I am interested in the way atoms and molecules are
packed in crystal structures and what determines the colour
of gemstones. Therefore I chose to test how cooling affects
the absorption spectra of gemstones. To identify them, a spectroscope
is one of the most complete instruments used. However, it has
some limitations. Therefore, the main subject of my project
was to find a method that would improve the absorption spectrum
of a gemstone and reduce the possibility of misinterpretation.
The absorption power of a gemstone is dependent on the amount
of energy it possesses. The more energy it has, the less it
will absorb. Thus the research question of the project was whether
cooling a gemstone would increase its absorption power. The
absorption spectra of gemstones were measured at temperatures
between +25øC and 196øC. The results obtained showed that it
is helpful indeed to cool gemstones before measuring their absorption
power, because it does increase the absorption power of gemstones.
This means that the data obtained from the spectroscope became
more understandable and the risk of misinterpretation of data
is lower .
