My Popular Articles
14,540 pts

Harlan Bengtson

Senior Writer
Contributions: 171
Member of: 2 channels
Member since:
July 06, 2009

  • Easy to Understand Diagram of the Nitrogen Cycle

    Nitrogen can exist in 7 oxidation states, ranging from a valence of -3 to a valence of +5. An easy diagram of the nitrogen cycle shows how nitrite, nitrate, ammonia and proteins are interrelated in a simple nitrogen cycle. A more comprehensive nitrogen...
    Published on  December 1, 2014 to Environmental Science

  • Solar Energy Quiz

    Are you a solar energy expert ... or an interested novice? Take this quiz, see where you rank, and perhaps learn more about solar energy and how solar energy is being put to use for passive solar heating, photovoltaic panels, and active solar heating...
    Published on  September 13, 2011 to Renewable Energy

  • Variations in Activated Sludge Wastewater Treatment Systems

    Activated sludge waste water treatment systems are the most widely used type of biological wastewater treatment for removal of biochemical oxygen demand from wastewater. All activated sludge process variations bring dissolved oxygen, aerobic bacteria...
    Published on  May 27, 2011 to Environmental Science

  • Biological Wastewater Treatment Systems for Removal of Biochemical Oxygen Demand

    Biological waste water treatment systems remove organic matter (biochemical oxygen demand) from waste water, utlizing dissolved oxygen by aerobic bacteria. Activated sludge, trickling filter and waste water treatment lagoons are common types of...
    Published on  May 25, 2011 to Environmental Science

  • An Introduction to Primary, Secondary, and Advanced Wastewater Treatment Methods

    Wastewater treatment plants may use primary, secondary, and/or tertiary (advanced) treatment. Primary wastewater treatment is sedimentation. Secondary treatment is typically biological oxidation to remove biochemical oxygen demand. Advanced...
    Published on  May 24, 2011 to Environmental Science

  • Features and Options of the Best Wood Pellet Stoves

    Wood pellet stoves have become increasingly popular, and quite a variety of styles are now available. If you want to choose from among the best wood pellet stoves, you need to know what features are available and which you want for your wood pellet stove...
    Published on  May 19, 2011 to Green Living

  • Concentrating Solar Power Technologies 1: Introduction to Alternatives

    Four concentrated solar power technologies are in various stages of development and commercialization. Those technologies, which are discussed in this article, are: parabolic trough, parabolic dish - stirling engine, heliostat solar power tower, and...
    Published on  May 17, 2011 to Renewable Energy

  • What is the Best Height for a Wind Sock?

    ICAO Annex 14 and FAA specifications for wind sock height and size provide information needed to design a properly functioning airport wind sock. Wind socks also are used for farms, marine applications, and general use.
    Published on  January 19, 2011 to Renewable Energy

  • Types of Solar Hot Water Systems

    Types of solar hot water systems include passive solar water heaters or active solar hot water heating. Solar water heaters also may be either direct water heating or they may use anti-freeze, where necessary to prevent freezing of water in the solar...
    Published on  January 9, 2011 to Renewable Energy

  • History Of Solar Energy

    The history of solar energy can be traced back to passive solar heating of buildings by the Greeks and Romans, through discovery of photovoltaic principles, development of photovoltaic solar panels, and the current continuing growth of solar thermal and...
    Published on  January 6, 2011 to Renewable Energy

showing 1-10 of 35    < Previous  |  page: 1 2 3 4  |  Next >