Gravity is used by spiral concentrators when particles of different densities are to be separated.  It should not be confused with separating particles of different sizes, which is done using a Spiral Classifier. 
 

Helical profiled troughs supported on a central column are the main parts of the spiral concentrator.  Low and high particles are separated and stratified with the help of adjustable splitters at the end of the spiral.  This is done as the slurry travels down the spiral. 
 

Click here to read more on separation using dense media, also known as dense media separation.       

Flavored coffees continue to grow in popularity yet obviously the beans aren’t grown with flavoring. So how is coffee flavored? Well while the beans aren’t grown that way they are grown to be able to accept flavoring and still taste great. Coffee beans contain more than 800 compounds, and each one will affect the way the coffee tastes. Additionally, where it is grown and how it is roasted will also have an impact. So for great flavored coffee you have to start with the right bean.

Read more at: How Is Coffee Flavored

The beauty and everlasting qualities of crystals and gems make them ideal gifts for just about anyone. There are many kinds of crystals in the world. Of these, the ones classified as precious stones include rubies, diamonds, emeralds and sapphires.

The semi precious gems include quartz, topaz, turquoise, and aquamarine, just to name a few. They all make good birthday gifts and jewelry for young and old. Crystals have very good conductivity of static electrical charges generated by our bodies.These are believed to have a healing effect on the body, because they help to modulate the unseen energy currents in our bodies. That is why, crystals are becoming increasingly popular as alternative healing instruments.

For more great info on crystals and gemstones, check out Crystals Gems.

The popularity of bird watching just continues to grow and with good reason. First, just about anyone can participate in birding. Second, it can be as convenient as walking out to your backyard. And best of all, when just beginning, no expensive equiment or special training is required. In fact, the only thing that is required to get started is an interest in birds.

To learn more, check out Bird Watching for Beginners on the About Bird Feeders site.

You can offer your children or grandchildren a head start to spark their interest in astronomy by giving them a kids telescope with which to view the stars. While it is true that you can buy a cheap kids telescope for under $10, if you hope for them to foster a sincere interest in astronomy, you should plan on shelling out $300 to $400 on a quality piece of equipment.

Telescopes in this price range are really toys and while they may hold a younger child’s interest, for those over the age of about eight, a more substantial kids telescope will not only spark an interest, it is likely it would hold their interest longer than a weekend camping trip.

To find out more about astronomy telescope visit our website.

Epithelium is a tissue composed of epithelial cells. Such tissue tends to surround parts of the body, somewhat like a cell membrane. It is also used to form glands.

The epithelium is usually the layer of cells ‘closer’ to the outside world. The outermost layer of our skin is composed of dead squamous epithelial cells, as are the mucous membranes lining the inside of mouths and body cavities. Other epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands…

Read more in Epithelium

Initially organic farming was an attempt to preserve “good farming” practices in the face of a rapidly changing agriculture, but today, organic farming are farming techniques that preverve the environment, in particular not using chemicals nor genetically engineered products. Since the early 1990s, the consumer market has enjoyed a double digit growth rate. Read full article in French on: L’agriculture biologique - More resources: Potimarron

A homemade solar power generator is wonderful in the event of a power outage and enables you to have a life outside of the power grid. Using the solar power generator to produce electricity you can power up a computer, modem, VCR, TV, camera, lights as well as DC appliances. It’s ideal for use in a cabin, boat, tent or when traveling around the world. There are certain steps that need be followed to build a solar power generator, but it is an easy process once you have the right ingredients.
Solar Power Generator

A high end compressed air flow meter can work with varying loads and will have no problem with vibrating environments. The main reason why people install this compressed air flow meter is to optimize their compressed air plant usage, and in that sense it is best to choose a design which is both efficient and effective but also adaptive to its operating environment .
Compressed Air Flow Meter

Newer homes are built with energy efficiency in mind and can save a lot of money with a solar array. Older homes, however, waste energy and can’t be fully supplied by solar energy.
Solar Power Water Heater