Water in Singapore

                                        Independent Research-Term 2

     Hi all, welcome to this post on Singapore's water.

      To start of, before you read this article, you may have started to think. Where does Singapore's water come from? Why do we say that Singapore's water is so clean that it can be drank directly from the tap?
     Well, these questions bothered me a little when I was tasked to do this article. Many would say that it's because of  NEWater. Very simple answer. However, I will be looking more deep into how Singapore manufactures its water and the Science that our water contains.
     We first have to start from basics. Singapore has four main sources of water, known as our Four National Taps. They are:
1)Water from local catchment areas(like reservoirs)
2)Imported Water(most from Malaysia)
3)Reclaimed Water(the famous NEWater)
4)Desalinated Water

      Great. We are now done with the basics. Now the science part. I will be focusing more on one of the National Taps today -NEWater as it covers on the method of Reversed Osmosis, one of the many methods of purifying water.

     What is reverse osmosis? Basically, contaminated water is forced through from one side to the other side of a semi-permeable membrane. Since the contaminants are kept on one side, we can obtain purified water on the other side of the membrane.(A pictorial explanation is shown on the left)

      Interestingly, reverse osmosis is not the only way to purify water. Other methods include Boiling water(Distillation Method), Ion Exchange(using the idea of positive and negative ion attraction to removed unwanted substances), Carbon Absorption(using carbon to take in impurities), Ultra Filtration(using molecular sieves), Ultraviolet treatment(ultraviolet light kills bacteria) and many more.
      

Ion Exchange

Distillation Method

    

Ultra Filtration

Carbon Absorption

Ultraviolet Light Filtration

        Why then does Singapore use Reverse Osmosis? For a start, organics with boiling points lower than 100 °C cannot be removed efficiently and can actually become concentrated in the product water. Distillation also requires large amounts of energy and water. Not cost effective! Next, Ion Exchange does not effectively remove most organics or microorganisms. Carbon Absorption  is usually used in combination with other treatment processes, which means that depending solely on this is not enough. Similar to Ion Exchange, Ultra Filtration membranes will retain most, but not necessarily all, molecules above their rated size. Lastly, Ultraviolet Light Filtration will kill bacteria but not necessarily filter off contaminants.

         So, comparing all the different filtration methods, seems like Reverse Osmosis still wins after all! 
Credits:
Michigan State University
esp water products
PUB-Public Utility Board
 LT Technology
 Pro Brewer.com
IJAPS 
Aid Gear
Emerald Insight
About.com
                          
                                       

Hello everyone! Welcome to this interesting post on Brownian Motion, Diffusion and the Plasma Ball.

In this lesson, we had the glory of going to the science to see Brownian Motion! Real, right before our eyes under the microscope! Cool? It's a pity I don't have any videos of it here as the photo quality was not very good.

Now this was what we saw.The smoke particles moved in random direction and continous motion and that increasing the temperature will cause the particles to move faster and more vigorously. After the experiment, Mr Tan, our Science Teacher, then explained why the smoke particles were visible to the eye while the air molecules were 'invisible'? Brownian Motion needs air and smoke particles in this case right? Well, the reason this happens is that the size of the smoke particles are larger than the air molecules and can reflect more light into our eyes. Also, interestingly, at 0 Kelvin, the particles will also become stationary!

Next, we worked on diffusion.(*note: no photos again)

Apparatus: Two petri dishes, olive oil, a needle and a supply of cold and hot water.

Steps:1)Place both Petri Dishes on a flat and dull surface. Pour cold water into one and hot water into the other. Illuminate both dishes with strong light from above.
          2)Dip the needle into olive oil and touch the tip of the needle to the cold water surface. Next, use the same needle to apply the same amount of oil into the hot water surface.
          3)Observe how the oil spreads out over the water surface in the two dishes.
          4)Obsercve how the oil film move and the differences in appearance and motion of the two oil films.

Apparently, the experiment failed terribly, with unexpected results. So, what I am going to post next is what ought to happen. The oil will spread out over a larger surface area and moves slowly in the cold water. However, the drop in the hot water will spread faster but over a smaller surface area. This shows us diffusion- the oil spreads out from higher concentration to lower concentration!

Lastly, it is the plasma ball.When a hand is placed near it, it forms filaments of light linking the core to the glass surface. Cool right? When flourescent light is placed near it, the flourescent light tube is ignited due to static electricity.

The Eye Amazing Implants

                                         Independent Research-Term 2

Hi all. Welcome to this post. In here, I am going to introduce an amazing science discovery which helped to change the darkness of the blind to light.

Title of chosen article:Eye implant restores vision to blind patients

      Overall, the main purpose of this article is to report about this new scientific discovery. The key scientific question this author is asking is: Is the blind fated to be blind forever?

        In here, the writer starts with the doctors findings of this new mechanism. He then continues with what happens to a blind person and how this device helps him.Basically, what happens when someone goes blind is that the cells responsible of converting light into electrical pulses to the brain have died. What this chip does is simply replicate what happens to these dead cells and transmit these signals to the brain.

      I feel that this article can be trusted as it evidence to support that it works. As stated:

  

 "Two blind men can see again after being given electronic eye implants in the first successful trial in the UK."

 Moreover, this company, The Telegraph, is not the only ones who wrote about this. Others include:The Guardian and MIT Technological Review. However, the set back is that this implant works best on this form of blindness calledretinitis pigmentosa (RP).As stated;

"Doctors said the patients, who have an inherited form of blindness called retinitis pigmentosa (RP), had regained "useful vision" just weeks after having a light-sensitive microchip inserted into the back of their eye."

 Also, the implant does not allow the person to fully regain his or her eyesight. Which means that more can be done in the research of this form. As stated in the article:

"The patients can see fairly basic shapes and distinguish a white plate on a dark table, for example. It may be that with time their vision becomes more refined because the brain has to relearn how to see."