Science by Email 24 February 2012

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	24 February 2012
News: Making visible the invisible By Sarah Kellett PET scan of the Brain. Our world is made of atoms, each with a core of protons and neutrons. Change the number of protons and the element changes: hydrogen becomes helium, or uranium becomes lead.   Change the number of neutrons in an atom and you get an isotope. For example, fluorine-18 has one less neutron than fluorine found naturally on Earth. Fluorine-18 is radioactive and decays, sending out energy as radiation. Glucose is the sugar used by brains and other organs.  By attaching fluorine-18 to glucose the sugar’s movement can be traced by measuring the isotope’s radiation. Tumours eat more sugar than healthy cells and show up bright on medical instruments. This is called a PET scan. But there’s a catch – a bottle of fluorine-18 decays so fast that in two hours only half of it is left. So it has to be made and used quickly. “We have a PET cyclotron (which makes fluorine-18) at TRIUMF, and a chemistry lab where we can add the fluorine to glucose,” says research scientist Tom Ruth from Canada’s National Laboratory for Particle and Nuclear Physics, TRIUMF. Something like a giant pea-shooter moves the fluorine-18 from TRIUMF, where it is made, to the hospital where it is used. “We put it in a small canister the size of a toilet roll, and it’s sent through a tube to the hospital. It takes about two minutes,” says Tom. In Australia we have a research reactor called OPAL that creates technetium-99m, another useful radioactive isotope used to diagnose cancer. Most of the world gets technetium-99 from two other nuclear reactors, which are getting pretty old and often close for repairs. Research is finding new ways to make radioactive isotopes, creating cyclotrons as small as a dining room table. More information World Nuclear Association: Radioisotopes in medicine Australian Nuclear Science and Technology Organisation videos Careers link Nuclear Science and Technology – Pathways
You will need these materials.   Use the marker to label the three jars.   Fill each jar with soil, sand or gravel to the mark. Pour in the same amount of water into each.   Try this: Thirsty rocks You will need 3 tall, thin jars of the same size and shape Sand Gravel Soil Water Food colouring Permanent marker What to do Use the marker to label all three jars at the same height, around halfway. Fill each jar with either sand, gravel or soil up to the mark, so that each jar has the same amount of material in it. Use the measuring jug to pour the same amount of water into each jar; make sure you have more water than the amount of material but not enough to fill the jar. Add a few drops of food colouring to the jug before pouring the water into the jar. Wait to ensure the water has filtered all the way through the materials. Compare the water levels in the jars. What’s happening? When you fill the jars, the water works into the gaps between the sand and rocks, even the ones that are too small for us to see. The water is heavier than air so it pushes the air up and out as bubbles. The different sized materials let more or less water through. If more water gets into the gaps, there will be less left up the top. The jar with the lowest water level has the most porous material and the highest water level has the least porous material. Applications Tiny holes inside rocks are called pores, so a measure of how much water, gas or oil can be in a rock is called porosity. Underground oil and gas deposits can be found in the pores of rocks, and it is where carbon dioxide could be stored. Over millions of years oil and gas filter through porous rocks that can hold them, but they need a cap of less porous rock above that will stop them escaping. This could also be a way of storing extra carbon dioxide, replacing oil or gas that is taken out and burned. By Deb Hodgkin CREST question: Does temperature affect porosity? Design and carry out an investigation to test this.   Try another Science by Email activity using sand and water More information How can we tell if rocks are porous and/or permeable? CSIRO link: Carbon capture and storage View the online version Quiz questions 1. Magnetite is an oxide of which metal? 2. What travels at approximately 300 000 kilometres per second? 3. What are thermophiles? 4. Which of the following threaten the existence of animal breeds with low genetic diversity: a) weakened immune system, b) lower fertility rate, c) higher infant mortality rate, d) all of the above? 5. In which Australian state would you find wild Sarcophilus harrisii? Did you know? Researchers from the University of New South Wales have made a transistor (an electrical component (an electrical component used in computer chips) consisting of a single phosphorus atom placed in a silicon crystal. Websites Read it! Separating fact from fiction is hard work – find out how myths can be debunked in this handbook. Watch it! In a contest between a straw house and a bushfire, which would win? Find out in this video. Events National: Schools Clean Up Day Clean Up Australia Day is Australia’s largest community environmental event, removing over 200 000 tonnes of rubbish from the environment over the past 20 years. Friday 2 March is Schools Clean Up Day and is a chance for your school to help your local environment. To find out more information and how to register your school, head over to the Schools Clean Up Day website. Team sports, Sunday 26 February at 7.30 am on Network Ten What do lawn bowls, basketball, rowing, ice hockey and netball all have in common? They're all team sports and they're all packed full of science! Join Dr Rob as he takes to the ice, the court, the green and SCOPES out all the science behind team sports, once again proving that the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 1 March: Modelling Sunday 3 March: Clothing science Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. Magnetite is an oxide of iron. 2. Electromagnetic radiation, such as light, x-rays and microwaves, travels at about 300 000 kilometres per second. 3. Thermophiles are microbes that live and grow in high temperatures. 4. d) all of the above. 5. You would find wild Sacrophilus harrisii in Tasmania – it’s the scientific name for the Tasmanian devil. Researchers have mapped the Tasmanian devil’s genome for the first time. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Jasmine Leong | Manage your subscription | FAQ

 

 

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