Geology: an overview

Have you chosen a course to do at university? Are you still in doubt? It is a very important decision to make and this article will certainly help. Every week we will introduce one course, which will give to high school students a general understanding how the courses are.

This week the course is geology. In Brazil, the duration is five years. In the first two years is the basic course and you will mainly study chemistry, maths and physics. From the third year to the last one, is the professional course. You will take geological subjects such as petroleum geology, geological engineering and environmental geology. The principally difference between geology and others courses is the fact that geology has field trips, which encompass key visits along the country, where you can practise and analyse in the field what you have learnt in class. As nature is everywhere, you will see geology all the time.

Nowadays, there are many job opportunities for geologists along with the increase of interest in geoscience among students. The salary is between five and twenty five thousands, but the average is about eight thousands in brazilian currency.

Next week we are going to talk about biology.

Geologist in a field trip.

-Monique Tebaldi

Ballast Water Management

The correct definition of ballast water management is to:

Deal with treatment defined as a process or mechanical, physical, chemical or biological method to kill, remove or render infertile, harmful or potentially harmful organisms within ballast water. Ballast water management involves precautionary water uptake practices and either mid ocean exchange.

Let me give you an example. Everyday various marine species are being carried around the world. When they are discharged into new environments, they may become invasive and severely disrupt the native ecology, impact economic activities such as fisheries and cause disease and even death in humans.

So, how do we solve this problem? It’s a difficult question. But the International Maritime Organization (IMO) Resolution A.868 (20) helps us. It requires:

1. All officers and crew involved in ballast water management to receive proper training.
2. All ships to minimize the transfer of harmful aquatic organisms and pathogens.
3. All ships to develop and follow a ballast water management plan
4. All ships to record all ballast operations

In addition, we have some techniques which are  used to minimize those impacts. The Ballast water exchange is currently considered the single most practical method for ballast water management. It can be accomplished by either the sequential empty-refill method or by overflow method. It has been reported that these methods are about 95% effective in eliminating aquatic organisms. Ballast Water Exchange operations should be performed in deep water away from coastal shelves and estuarine influences.

Overflow Method

To sum up many methods are being developed to minimize the risks of ballast exchange. These new methods are based in treat ballast water by filters and ultraviolet capsules.

Hiago Gaspar de Freitas

The Air Cannon

With simple everyday components and a little bit of Physics knowledge, you’ll be learning now how to make a simple but astonishing experiment: the air cannon.

Materials you need

• Plastic bucket without handle
• Plastic bag
• Tape
• Scissors or stiletto

The Experiment

Firstly, you have to cut a hole in the bottom of the bucket. This hole must have a smaller diameter than the open side and must be in the centre of the bucket.

After that, tape firmly the plastic bag over the opening that is opposite the hole. Be careful when taping, because the bag can’t contain any air leaks.

Then it’s ready to be played – yes, it can be used as an amazing toy! You only have to make some good targets, like your friend’s hair or some candles, and tap on the plastic so that the air goes outside the bucket.

What about Physics?

The subject being addressed on it is called Continuity Equation. It says that the flux of air inside the bucket is equal to the flux through the exit site, which is given by the product of the velocity in which air is flowing and the area it’s occupying. Therefore, the area is inversely proportional to velocity, so that the fluxes continue being the same both inside the bucket and at the exit orifice. That is to say, as the air occupies a smaller area when flowing through the open orifice, its velocity must be greater at this location so that it equals the flux on the whole process.

A_{1 .} V₁ = A_{2 .} V₂

Very interesting, isn’t it? To make it even more amazing, watch this video below showing the largest and most powerful air cannon the world has ever seen!

http://www.youtube.com/watch?v=ayaiArVkpA4

Gabriel Alves

Graphene – The future material.

New tendencies of the world demand new technologies, which means more and more researches and it was during one of this researches that the grapheme was found. A material as revolutionary as silicon and plastic, extremely strong, lightweight, flexible, great electric conductor and almost completely transparent, Graphene is one of the carbon crystalline forms such as diamond and graphite.

The studies of Graphene made ​​by Andre Geim and Konstantin Novoselov of Manchester University assured them the Nobel Prize in Physics in 2010. Their researches demonstrated how the usual touch screens, light panels and solar energy captors would be improved due to Graphene’s characteristics.

Lots of investments are being made not only to achieve Graphene’s total potential but also to figure out its functionality in all kinds of fields. It is already being studied Graphene’s applicability in:

• Batteries efficiency – as a super conductor it takes seconds to recharge the same amount of a usual battery and it offers the flexibility that no other battery material could do.
• Water filter – it can purify sea water into drinkable water by acting as a filter to the salts and it can also eliminate other substances from water such as radioactive ones.
• Internet speed – a new kind of data transmission cable to the internet made of graphene could optimize internet speed due to the electrons handling capacity in graphene being much higher than in the materials used today.

A short film introducing the ‘wonder substance’  that sums up everything: http://www.youtube.com/watch?v=dTSnnlITsVg&hd=1

João Felype