St. Joseph School, Science and Laboratory Club

25/02/2018

Video of the 3D printer demonstration

Saint Joseph school Addis Ababa Science and laboratory Club January 9 ,2018 meeting. Briefing and working procedure of Cartesian 3D printer and a Quad copter...

20/01/2018

Last year, a little measurement called the p-value was the focus of a big controversy as scientists argued it should be lowered to help address a major problem in modern science.

20/01/2018

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17/01/2018

Even after a good night's sleep, all it takes is one rough commute or frustrating meeting to majorly wear us down.

10/01/2018

3D Printer and Drone shown by Ato Zelalem during this week's Science and Laboratory Club meeting

10/01/2018

GREEDY BAHR - ZAF (Eucalyptus Tree)

The Eucalyptus tree, according to some documents, is imported from Australia.
Its Amharic name refers to it as a tree from abroad. The tree was imported during
the reign of Menilik II. The king ordered the import of the tree because there was
a shortage of wood for fuel in the country. Many of the indegenous trees had been
cut down by inhabitants for fuel.

Today many people in Ethiopia use Eucalyptus poles for building houses. People
use the Eucalyptus as a source of income. In two or three years they can make more
money by planting Eucalyptus trees than planting other cash crops. Moreover, both the
branches and the leaves of this tree are much used as a fuel in towns and rual areas.

The Eucalyptus tree has several advantages over other trees. It is not readily affected
by insets, it is very fast growing and is has a high resistance to drought; a great
advantage in areas of low rainfall. Its resistance to drought is partly the result of
an oily coating or cuticle on the leaves which give it a low transpiration rate and
partly a result of its extensive root system. Its true to say it is becoming a dominant
tree in the country.

But is the Eucalyptus tree really a long term investment for Ethiopia? What are its
long term effects on the soil? The Eucalyptus is a fast growing tree and therefore it
uses up minerals and water quicker than other plants around it. Eucalyptus leaves
contain a Polyphenol compound which finds its ways into the soil when leaves die. This
chemicals alter the balance of minerals in the soil. In particular they tend to remove
calcium from top layers of soil. Since calcium compounds help to bind the soil particles
together this process leads to a serious erosion. Other important minerals such as iron
and aluminium are also affected and are not available for other plants. This chemical process
alter the chemical and physical nature of the soil and the process is called Podosolization.
"Podosol" is a Russian term which refers to elevation of aluminum and iron, usually producing
an ashy surface soil in amorphous clay and mica and a leaching of calcium salts which bind
the soil together. Podosolization results in the formation of reddish soil, rich in iron and
aluminium, with poor binding qualties and a low calcium and humus content. Such soils are very
sensetive to erosion by wind and rain.

Source~Tsehaye Sebhatu

04/01/2018

We are officaly online.