What is Glass?
A new type of glass has been created. But first, what is glass? It is an odd substance that even to this day is not very well understood. Even though it seems solid, it is considered a liquid by some. This is primarily because of its random structure. The article on glass in Wikipedia calls it a “non-crystalline amorphous solid”.
What is Glass Made Of?
Glass is made by melting different minerals together at a high enough temperature. The primary one is silicon dioxide (about 75%) which is what sand is mostly made of. You may also know silicon dioxide as quartz. Sodium oxide, sodium carbonate and calcium oxide are the other primary constituents of glass.
Newly Discovered Glass
This new glass was discovered by accident. Rather than being random and amorphous, it has structure. They made the glass for a different reason, not expecting do discover glass with structure. But, when they tested their creation spectroscopically, instead of the random pattern that you usually get with glass, this sample had peaks and a definite pattern which indicated that the molecules in the glass were arranged in a regular pattern.
How to Make Structured Glass
Normally glass is made by melting the minerals together and pouring it out in a sheet or into a mold. With this glass they were doing vapor deposition. They heated up the glass and then would spray a thin layer at a time, over and over again until the layers built up and it became thick.
Temperature is critical in the process since you need to get the glass hot enough to melt and spray but not too hot because it then has to hit the newly formed glass and cool and solidify. So there is a very narrow temperature range which is feasible.
Key is Layering the Glass
By putting down a very thin layer at a time, it is thought that this traps the glass molecules in a certain orientation. Interestingly, once the glass cools and sets it keeps the orientation of all the molecules even if it is reheated. (Unless of course you go all the way to where it melts.)
Now, they are playing with the process and seeing how the properties of the glass change and how they can come up with different qualities and uses for these new types of glass. They will also probably modify the ingredients in the glass to see what effects they will have.
Most people think of hydropower as an old technology that hasn’t changed significantly in many years. A company called Natle Energy has come up with a new design for a turbine. The turbine is the part that generates the power.
How do turbines work?
You can have turbines that work just from the flow of a river or tidal flow, but normally there is a dam that holds back the water. Then you use the energy contained in the falling water to generate electricity. The way this works is that some or all of the water going down river is channeled into a channel or tube called a penstock. This focuses the water on a turbine. Turbines have different designs depending on the amount of flow and the amount of head. Head is the height which the water falls. But basically, a turbine has blades that the water pushes against and causes it to turn.
Some of the turbines look like propellers, some look like the blades in jet engines. There are several variations, but they haven’t changed that much in decades.
Once the water is turning the turbine, a shaft from the turbine is connected to a generator and causes that to turn. The generator is what generates the electricity.
Problems with Turbines
One of the problems with turbines is fish. Any fish coming downstream that go through the turbine are usually killed. One reason is simple physical trauma. But another is less obvious, pressure change. Fish are very sensitive to pressure changes and the pressure change can be very abrupt and sudden as a fish goes through the turbine which can be deadly. That is why many dams have fish ladders to allow the fish to go around the dams.
Fish ladders and sometimes fish elevators (if the dam is very high) are not always very effective. That is where Natle Energy has come up with an interesting solution. It can decrease the cost of the turbine and at the same time is much more friendly to fish.
Venetian Blind Turbine
The Natle Energy turbine looks kind of like a Venetian blind that has been made into a loop and turns around a top and bottom axle. The water flows through the side moving up, pushing it up and then because of the curve of the blade in the Venetian blind the flow angles down and pushes down the “blind” blades on the back side of the loop. So the water works twice, pushing the front side of the loop and pushing down the back side, making it rotate faster.
This turbine would be used in low head situations. Other turbines for low head situations such as the Kaplan or propellers or Hydromatrix are not fish friendly. The neat thing about the Natel Energy turbine is that it is fish friendly and they are smaller, lower cost and generate the same amount of power. The fish can swim right through a Natel Energy turbines without a problem. Neat new technology.