GC: adj CT: The minimum amount of runoff that must be preserved in order to maintain basin salt balance is conceptually calculated. The alternative, the conversion of all runoff into evapotranspiration, is unsustainable, because it will cause salts to accumulate without limit. Nature intended exorheic drainage basins to be in

GC: n CT: Paralyzed from the waist down after a BMX accident, Steven Sanchez rolled into SuitX’s Berkeley, California, office in a wheelchair. A half-hour later he was standing and walking thanks to the Phoenix—a robotic exoskeleton now available for around $40,000. The suit returns movement to wearers’ hips and

GC: n CT: An expansion tank is a metal tank connected to a building’s water heating appliance designed to accommodate fluctuations in the volume of a building’s hot water supply system. These fluctuations occur because water expands in volume as it gets hot and loses volume as it cools. Expanding

GC: n CT: Expert Systems are computer programs that are derived from a branch of computer science research called Artificial Intelligence (AI). AI’s scientific goal is to understand intelligence by building computer programs that exhibit intelligent behavior. It is concerned with the concepts and methods of symbolic inference, or reasoning,

GC: n CT: EXPERT SYSTEMS BUILDING TOOLS: DEFINITIONS An expert system tool, or shell, is a software development environment containing the basic components of expert systems. Associated with a shell is a prescribed method for building applications by configuring and instantiating these components. Some of the generic components of a

GC: n CT: In 1831, Michael Faraday, an English physicist gave one of the most basic laws of electromagnetism called Faraday’s law of electromagnetic induction. This law explains the working principle of most of the electrical motors, generators, electrical transformers and inductors. This law shows the relationship between electric circuit

GC: n CT: “Cybernetics” comes from the Greek: “the art of steering”. In short, cybernetics is a discipline for understanding how actions may lead to achieving goals. Knowing whether you have reached your goal (or at least are getting closer to it) requires “feedback“, a concept that comes from cybernetics.

GC: n CT: Energy flow. As we have seen, generating and utilising energy means converting energy from one form into another. Often, intermediate steps are Implied. The energy flows through a number of forms, as well as conversion steps, between the source and the end-use. The costs increase accordingly. We

GC: n CT: The trend in final energy consumption by fuel type and by sector provides a broad indication of progress in reducing final energy consumption and associated environmental impacts by the different end-use sectors (transport, industry, services and households). The type and magnitude of energy-related pressures on the environment

CG: n CT:  A firewall is a system designed to prevent unauthorized access to or from a private network. You can implement a firewall in either hardware or software form, or a combination of both. Firewalls prevent unauthorized internet users from accessing private networks connected to the internet, especially intranets. All

See nuclear fission

GC: n CT: Pyrolysis is thermal degradation either in the complete absence of oxidizing agent, or with such a limited supply that gasification does not occur to an appreciable extent or may be described as partial gasification. Relatively low temperature are employed of 500 to 800 °C, compared to 800

GC: n CT: Flash steam power plants use hot water reservoirs. In flash plants, as hot water is released from the pressure of the deep reservoir in a flash tank, some if it flashes to steam. S: http://geothermal.marin.org/geopresentation/sld054.htm (last access: 26 February 2015) N: 1. Flash Steam Power Plants are

CG: n CT: Floating buoys have been developed which can generate energy from the bobbing or pitching motion caused by the waves. In some buoy type systems the buoy uses a simple mechanical system to turn a crankshaft. For example, in the Indian I-wave system the wave action raises the

CG: n CT: Calibrating a Parshall flume. Decrease water velocity: If the water velocity is too fast, the relationship between depth and velocity will be way off A small increase in depth will give you a disproportionately large change in discharge rate. You need to find some way to dissipate

CG: n CT: Since liquids are incompressible fluids, their flow rate depends only on the difference between the inlet and outlet pressures (Δp, pressure drop). The flow is the same whether the system pressure is low or high, so long as the difference between the inlet and outlet pressures is

GC: n CT: There are many types of open channel flow measuring devices available. Of these, flow measuring flumes are one of the most commonly used. How a Flume Operates Flumes are specially shaped, fixed hydraulic structures that under free-flow condtions force flow to accelerate in such a way that

GC: n CT: The rear apron in the Merala weir is of as soUd construction as the fore apron and is built on a slope right up to crest level; this arrangement facilitates discharge. The velocity of approach must be very great to necessitate huge book blocks of concrete 6X6X3

GC: n CT: Evidence for early agriculture can be obtained from pollen profiles indicating forest clearance. The practice of cultivation is widely believed to have been introduced into the interlacustrine region of central Africa by Bantu-speaking iron-workers, present by 2,000 yr BP (ref. 3) or, disputedly, 2,600 yr BP (ref.

GC: n CT: Forest residues consist of small trees, branches, tops and un-merchantable wood left in the forest after the cleaning, thinning or final felling of forest stands, used as fuel without any intermittent applications. Three main sources of forest residues can be distinguished: slash from final fellings, slash and

GC: n CT: There are three major forms of fossil fuels: coal, oil and natural gas. All three were formed many hundreds of millions of years ago before the time of the dinosaurs – hence the name fossil fuels. The age they were formed is called the Carboniferous Period. It

GC: n CT: Hydraulic fracturing, or fracking, is shunned by the environmentalists that laud renewable energy sources. However, by not supporting both initiatives, they may be working at cross purposes. Natural gas, booming largely because of fracking, complements renewable energies on the grid. The two seemingly opposite technologies are, for

GC: n CT: Refrigeration capacity. The thermal size of a refrigerator is known as its capacity, i.e. its cooling power, in watts in SI units, but sometimes older units are used in some places, as the frigorie/hour (4180/3600=1.16 W) or the ton (3575 W). It might be argued that it

GC: n CT: Biomass is matter usually thought of as garbage. Some of it is just stuff lying around -dead trees, tree branches, yard clippings, left-over crops, wood chips (like in the picture to the right), and bark and sawdust from lumber mills. It can even include used tires and