Energy povertyEnergy poverty is lack of access to modern energy services. It refers to the situation of large numbers of people in developing countries and some people in developed countries whose well-being is negatively affected by very low consumption of energy, use of dirty or polluting fuels, and excessive time spent collecting fuel to meet basic needs. Today, 759 million people lack access to consistent electricity and 2.6 billion people use dangerous and inefficient cooking systems.
Filter (signal processing)In signal processing, a filter is a device or process that removes some unwanted components or features from a signal. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal. Most often, this means removing some frequencies or frequency bands. However, filters do not exclusively act in the frequency domain; especially in the field of many other targets for filtering exist.
WavelengthIn physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings. Wavelength is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency.
IntelliCADIntelliCAD is a CAD editor and development platform with an Application Programming Interface API published by the IntelliCAD Technology Consortium ("ITC") through shared development. IntelliCAD emulates the basic interface and functions of AutoCAD, however, it is particularly able to incorporate and interchange freely between a wide variety of file types (i.e. dwg., BIM, TIFF, etc.).
Transatlantic telegraph cableTransatlantic telegraph cables were undersea cables running under the Atlantic Ocean for telegraph communications. Telegraphy is now an obsolete form of communication, and the cables have long since been decommissioned, but telephone and data are still carried on other transatlantic telecommunications cables. The first cable was laid in the 1850s from Valentia Island off the west coast of Ireland to Bay of Bulls, Trinity Bay, Newfoundland.
Energy economicsEnergy economics is a broad scientific subject area which includes topics related to supply and use of energy in societies. Considering the cost of energy services and associated value gives economic meaning to the efficiency at which energy can be produced. Energy services can be defined as functions that generate and provide energy to the “desired end services or states”. The efficiency of energy services is dependent on the engineered technology used to produce and supply energy. The goal is to minimise energy input required (e.
Traveling-wave tubeA traveling-wave tube (TWT, pronounced "twit") or traveling-wave tube amplifier (TWTA, pronounced "tweeta") is a specialized vacuum tube that is used in electronics to amplify radio frequency (RF) signals in the microwave range. It was invented by Andrei Haeff around 1933 as a graduate student at Caltech, and its present form was invented by Rudolf Kompfner in 1942-43. The TWT belongs to a category of "linear beam" tubes, such as the klystron, in which the radio wave is amplified by absorbing power from a beam of electrons as it passes down the tube.
High-electron-mobility transistorA high-electron-mobility transistor (HEMT or HEM FET), also known as heterostructure FET (HFET) or modulation-doped FET (MODFET), is a field-effect transistor incorporating a junction between two materials with different band gaps (i.e. a heterojunction) as the channel instead of a doped region (as is generally the case for a MOSFET). A commonly used material combination is GaAs with AlGaAs, though there is wide variation, dependent on the application of the device.
Weather radarWeather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern weather radars are mostly pulse-Doppler radars, capable of detecting the motion of rain droplets in addition to the intensity of the precipitation. Both types of data can be analyzed to determine the structure of storms and their potential to cause severe weather.
Oliver HeavisideOliver Heaviside FRS (ˈhɛvisaɪd; 18 May 1850 – 3 February 1925) was an English self-taught mathematician and physicist who invented a new technique for solving differential equations (equivalent to the Laplace transform), independently developed vector calculus, and rewrote Maxwell's equations in the form commonly used today. He significantly shaped the way Maxwell's equations are understood and applied in the decades following Maxwell's death.
James Clerk MaxwellJames Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish physicist with broad interests and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the "second great unification in physics" where the first one had been realised by Isaac Newton.
Optical filterAn optical filter is a device that selectively transmits light of different wavelengths, usually implemented as a glass plane or plastic device in the optical path, which are either dyed in the bulk or have interference coatings. The optical properties of filters are completely described by their frequency response, which specifies how the magnitude and phase of each frequency component of an incoming signal is modified by the filter. Filters mostly belong to one of two categories.
