6 Matching Annotations
  1. May 2018
  2. May 2017
    1. heat trace (heating cable)
      Heat trace or heating cable is used to warm or heat underground structures, storage tanks, vessels, and instrumentation in order to maintain a specified temperature or eliminate the possibility of freezing. Heat trace or heating cable accomplish this task by adding the amount of heat energy to the process fluid that is lost from the process fluid. It is desirable to maintain a certain temperature since higher temperatures reduce viscosity, enhance combustion, and prevent freezing or crystallization of the fluid. Within the oil and gas industry, elevated temperatures are required to separate the crude oil or raw natural gas to the surface and freeze protection is required to allow refining and distribution of the fluid (Thermon South Africa (Pty.) Ltd. ). Heat trace or heating cable often utilizes resistance wire to provide a medium for voltage to pass through. Due to the resistance of the wire, the heat trace or heating cable becomes warmer and is able to use this heat to warm the underground structures that it surrounds. One material used in resistance wires is nickel-chromium (Peterjohn, Melillo, Bowles, & Steudler, 1993). Heat trace has been used since the early 1900s to ensure the proper flow of petroleum, tar, and wax through pipelines. Since then, certain products within the petroleum and chemical industries needed to be kept between specific temperatures to ensure their quality. Today, the most commonly used heat trace medium is steam (Thermon South Africa (Pty.) Ltd. ). 
      

      References

      Peterjohn, W. T., Melillo, J. M., Bowles, F. P., & Steudler, P. A. (1993). Soil Warming and Trace Gas Fluxes: Experimental Design and Preliminary Flux Results. Oecologia, 18-24.

      Thermon South Africa (Pty.) Ltd. . (n.d.). Heat Tracing Technologies. Retrieved from Thermon South Africa (Pty.) Ltd. : file:///H:/Users/rrs020.BUCKNELL.000/Downloads/thermon-sa_heat-trace-technologies_energy-savings.pdf

    2. frost heave
      Before the understanding of frost heave, there was a widely held belief that rocks and stones could grow and multiply. Stones were believe to grow from small pebbles. These stones then rose to the surface of the ground. Another belief was that stones were the offspring of “mother-stones” or “breeding-stones.” Today, it is known that this motion of stones moving upwards toward the surface of the ground is due to frost heave. Frost heave occurs when water in soil or rock freezes and thaws in a cyclic process. This causes an upward movement of the surface of the ground due to the freezing of water underneath. Geologist Stephen Taber from the University of South Carolina proved through extensive research that “it was not expansion, but rather the formation of ice lenses by segregation of water from the soil as the ground freezes that is the principal cause of frost heave.” He also showed that liquids other than water can also cause frost heave. The direction of heave is governed by the growth of ice lenses. Ice lenses form perpendicular to the direction of heat flow, so it is not always the case that frost heave occurs in the path of least resistance (Manz, 2011). 
      

      References

      Manz, L. (2011). Frost Heave. Geo News, 18-23.

  3. May 2016
    1. lesh, the engineering manager, and Dubusker drew on all of McDonnell's experience with shingled-skin structures around jet afterburners for heat protection.
  4. Nov 2015
    1. LOPINOD is also being used to fund the development of a Low Carbon Plan. This plan will focus on the full spectrum of renewables including wind, solar, marine source heat pumps and tidal. It is hoped that we will become a hub for all green energy going forward, building on our existing involvement in the wind farm industry.

      Beachhead for solar, tidal, marine source heat pumps as well as wind energy

  5. Sep 2015
    1. ITM is based on the theory of temperament. Temperament is a quality resulting from the interaction of opposite properties present in elements consisting of minute particles. Thus, a uniform quality occurs which is present in all of them. Hotness, coldness, moistness, and dryness are four temperaments that naturally occur in every existingsubstance including living creatures (2)

      These temperments match up with the four-fold alchemical division that uses the same four qualities of heat, cold, moisture and dryness.