Equivalent noise resistance - Equivalent noise resistance In telecommunication, an equivalent noise resistance is a quantitative representation in resistance units of the spectral density of a noise-voltage generator, given by R n = (Ï€W n)/(kT 0), where W n is the spectral density, k is Boltzmann's constant, T 0 is the standard noise temperature (290 K), and kT 0 = 4.00 × 10-21 watt-seconds. Note: The equivalent noise resistance in terms of the mean-square noise-generator voltage, e 2, within a frequency increment, Δf , is given by R n = e 2/(4kT 0Δf ). Source: from Federal Standard 1037C.
Glossary of telecommunications transmission terms - see the Federal Standard article for copyright-related issues, as not all parts of the source document are in the public domain. Noise ambient noise level -- antenna noise temperature -- atmospheric noise -- background noise -- blue noise -- carrier noise level -- carrier-to-noise ratio (CNR) -- carrier-to-receiver noise density (C/kT) -- channel noise level -- circuit noise level -- closed-loop noise bandwidth -- C-message weighting -- cosmic noise -- effective input noise temperature -- equipment intermodulation noise -- equivalent noise resistance -- equivalent noise temperature -- equivalent pulse code modulation noise (PCM) -- equivalent satellite link noise temperature -- feeder echo noise -- flat weighting -- FM improvement factor -- FM improvement threshold -- front-end noise temperature -- HA1-receiver weighting -- idle-channel noise -- impulse noise -- in-band noise power.
Field effect transistor - and creates a so-called "inversion channel" in the channel underneath. Varying the voltage between gate and body modulates the thickness of this conductive layer and so makes it possible to control the current flow between drain and source. The schematic symbols for p- and n-channel MOSFETs. The symbols to the right include an extra terminal for the transistor body whereas in those to the left the body is implicitly connected to the source. MOSFETs are ideal for switching, especially in digital circuits and switched-mode power supplies. Their low on-resistance also makes them suitable replacements for diodes (so-called OR-ing diodes) used to connect the outputs of power supplies in parallel. The growth of digital technologies like the microprocessors have provided the motivation to advance MOSFET technology faster than any other type of.
Bel - taking the logarithm, to the base 10, of the ratio. Therefore, one bel corresponds to a ratio of 10:1. Mathematically, the number of bels is calculated as B = log10(P1/P2) where P1 and P2 are power levels. The neper is a similar unit which uses the natural logarithm. The bel is too large for everyday use, so the decibel (dB), equal to 0.1 B, is more commonly used. One decibel is equivalent to a ratio of about 1.259:1. It is defined as 10 log10(P1/P2) where P1 and P2 are the powers. The decibel is a dimensionless "unit". The decibel is not an SI unit, although the CIPM has recommended its inclusion in the SI system. Table of contents showTocToggle("show","hide") 1 Uses 1.1 Optics 1.2 Acoustics 1.3 Electronics 1.4 Telecommunications 1.5 Seismology.
Pickup - - along with the musical signal - they also pick up mains hum. Mains hum consists of a fundamental signal at a nominal 50 or 60 Hz, depending on where you are in the world, and usually some harmonic content. The changing magnetic flux caused by the mains current links with the windings of the pickup, inducing a voltage by transformer action. To overcome this effect, the "humbucking" pickup was developed, originally by the Gibson company. A humbucking pickup comprises two standard pickups wired together in series. However, the magnets of the two pickups are reversed in polarity, and the windings are also reversed. Thus, any hum or other common mode extraneous noise that is picked up is cancelled out, while the musical signal is reinforced. The turns of wire in.
Propeller - an airfoil, much like the wing of an aircraft, except that the shape of the airfoil varies along the length of the blade, however any point on the blade describes a helix as it moves through the air. The motion of the propeller blade, when placed at a positive angle of attack, produces forward thrust and tangential resistance. The resistance produces a turning moment about the propeller axis, called resistance torque, which it is necessary for the engine to overcome. An propeller's efficiency is determined by (thrust x axial speed)/(resistance torque x rotational speed). Changes to a propeller's efficiency are produced by a number of factors, notably adjustments to the helix angle, the angle between the resultant relative velocity and the blade rotation direction, and to blade pitch. Very small pitch.
List of electronics topics - 32VSB 4000 series 4VSB 555 741 7400 series 8VSB A Absolute gain Access control Acceptance pattern Access time Acoustic coupler Acquisition ADSL Adaptive communications Adder Adjacent-channel interference Alarm sensor Aliasing Alternate party Alternating current AM radio Amateur radio Ambient noise level American Radio Relay League (ARRL) AMI Ammeter Ampere Amplitude distortion Amplitude modulation Amplifier Analog Analog computer Analog decoding Analogue switch Analog to digital converter Angular misalignment loss Antenna Antenna blind cone Antenna effective area Antenna gain Antenna height above average terrain Antenna noise temperature Antenna theory aperiodic antenna aperture aperture illumination Aperture-to-medium coupling loss Apollo Guidance Computer Arithmetic and logical unit Armstrong oscillator ARRL Articulation score Astable Asynchronous communications system Asynchronous operation Asynchronous start-stop Atmospheric duct Atmospheric waveguide Attenuation Audible ringing tone Audio system measurements Automatic call distributor Automatic data.
Equivalent pulse code modulation noise - Equivalent pulse code modulation noise In telecommunication, equivalent pulse code modulation noise (PCM) is the amount of thermal noise power on a frequency-division multiplexed (FDM) or wire channel necessary to approximate the same judgment of speech quality created by quantizing noise in a PCM channel. Note 1: The speech quality judgment is based on comparative tests. Note 2: Generally, 33.5 dBrnC ±2.5 dB is considered the approximate equivalent PCM noise of a 7-bit PCM system. Source: from Federal Standard 1037C and from MIL-STD-188.
Noise-equivalent power - Noise-equivalent power Noise-equivalent power (NEP) is the radiant power that produces a signal-to-noise ratio of unity at the output of a given optical detector at a given data-signaling rate or modulation frequency, operating wavelength, and effective noise bandwidth. Note 1: Some manufacturers and authors define NEP as the minimum detectable power per square root bandwidth. When defined this way, NEP has the units of watts per (hertz)1/2. Therefore, the term is a misnomer, because the units of power are watts. Note 2: Some manufacturers define NEP as the radiant power that produces a signal-to-dark-current noise ratio of unity. The NEP measurement is valid only if the dark-current noise dominates the noise level. Source: from Federal Standard 1037C and from MIL-STD-188.
Johnson-Nyquist noise - Johnson-Nyquist noise Johnson-Nyquist noise (sometimes only "Nyquist noise") is the equilibrium fluctuations of the electric current inside an electrical conductor, which happen without any applied voltage, due to the random thermal motion of the charge carriers (the electrons). It is to be distinguished from Shot noise, which describes the additional current fluctuations that occur when a voltage is applied and a macroscopic current starts to flow. The strength of Nyquist noise is related to the temperature and the resistance of the conductor. See: Harry Nyquist, J. Johnson J. Johnson, "Thermal Agitation of Electricity in Conductors", Phys. Rev. 32, 97 (1928) -- the experiment H. Nyquist, "Thermal Agitation of Electric Charge in Conductors", Phys. Rev. 32, 110 (1928) -- the theory.
Non-violent resistance - Non-violent resistance Non-violent resistance is the practice of rejecting violence as a means toward socio-political change. Adopting non-violent resistenance may stem from a moral decision or from a recognition of relative military impotence. Like other strategies for social change, non-violent resistance can appear in various forms and degrees. It may include information warss, protest art, lobbying, tax refusal, boycotts or sanctions, legal/diplomatic wrestling, material sabotage, underground railroads, principled refusal of awards/honours, picketing, vigiling, leafleting, and/or general strikes. Gene Sharp has outlined tactics of non-violent resistance as a military strategy, designed to defend countries in the face of attempted takeover: symbolic protests hunger strike paralysis of transportation social boycotts specific and general strikes civil disobedience economic shutdowns political noncooperation "disappearance" under false identity economic boycotts public demonstrations slow-downs publication.
Noise (physics) - Noise (physics) In science, and especially in physics and telecommunication, noise is random fluctuations and the addition of external factors to the stream of target information (signal) being received at a detector. More specifically, in physics, the term noise has the following meanings: 1. An undesired disturbance within the frequency band of interest; the summation of unwanted or disturbing energy introduced into a communications system from man-made and natural sources. 2. A disturbance that affects a signal and that may distort the information carried by the signal. 3. Random variations of one or more characteristics of any entity such as voltage, current, or data. 4. A random signal of known statistical properties of amplitude, distribution, and spectral density. 5. Loosely, any disturbance tending to interfere with.
Vitamin C - in the kidneys, in reptiles and birds, or the liver, in mammals and perching birds. The loss of an enzyme concerned with ascorbic acid synthesis has occurred quite frequently in evolution and has affected at least some fish, many birds; some bats, guinea pigs and most but not all primates, including Man. The mutations have not been lethal because ascorbic acid is so prevalent in the surrounding food sources. Table Showing Abundance of Vitamin C in Raw Foods of Animal Origin Raw animal tissue Mg vitamin C per 100 grams of tissue Beef liver 31 Oysters 30 Pork liver 23 Calf liver 36 Artificial chemical synthesis Vitamin C is produced from glucose by two main routes. The Reichstein process developed in the 1930s uses a single pre-fermentation followed by a purely.
John Wyclif - this came from his activities in ecclesiastical politics, in which he engaged about the mid-1370s, when his reformatory work also began. In 1374 he was among the English delegates at a peace congress at Bruges. He may have been given this position because of the spirited and patriotic behavior with which in the year 1366 he sought the interests of his country against the demands of the papacy. It seems he had a reputation as a patriot and reformer; this suggests the answer to the question how he came to his reformatory ideas. [Even if older evangelical parties did not exist in England before Wyclif, he might easily have been influenced by continental evangelicals who abounded. It is highly probable that the older type of doctrine and practice represented by the.
Victor Cousin - for the first time. "That day decided my whole life." Laromiguière taught the philosophy of John Locke and Etienne Bonnot de Condillac, happily modified on some points, with a clearness and grace which in appearance at least removed difficulties, and with a charm of spiritual bonhomie which penetrated and subdued." Cousin wanted to lecture on philosophy, and quickly obtained the position of master of conferences (maître de conférences) in the school. The second great philosophical impulse of his life was the teaching of Pierre Paul Royer-Collard. This teacher, he tells us, "by the severity of his logic, the gravity and weight of his words, turned me by degrees, and not without resistance, from the beaten path of Condillac into the way which has since become so easy, but which was then.
Insulin - is because, at least in the short term, it is far less harmful to have too much glucose in the blood than too little. Mechanisms which restore too low blood glucose (hypoglycemia) must be quick and effective because of serious consequences of insufficient glucose. They are mostly efficient and symptomatic hypoglycemia is found almost entirely in diabetics on pharmacologic treatment. Hypoglycemic episodes vary greatly in severity and swiftness of onset. In severe cases prompt medical assistance is essential, as death results from sufficiently low blood glucose levels. Beta cells in the Islets of Langerhans are sensitive to variations in blood glucose levels because of the presence of glucokinase, which responds to glucose concentrations. If that level increases, more insulin from beta cell stores is released into the blood, and beta cell.
Information warfare - include giving the enemy propaganda to convince them to give up, and denying them information that might lead to their resistance. Information warfare may also include feeding propaganda or even disinformation to one's own population, either to build support for the war effort or to counter enemy propaganda. Information warfare may also mean a strategy for undermining an enemy's data and information systems, while defending and leveraging one's own information edge. This type of war has no front line; potential battlefields are anywhere networked systems can be accessed --oil and gas pipelines, electric power grids, telephone switching networks, etc. Information warfare can take countless forms: trains and planes can be misrouted and caused to collide, stock exchanges can be sabotaged by electronic "sniffers" which disrupt international fund-transfer networks, and the signals.
Izumo province - progenitor of the Izumo line, engaged Amaterasu Omikami (his sister), progenitor of the Yamato (Imperial) line, in a heavenly struggle for power on Earth. Amaterasu prevailed, but the myth of the Izumo godÕs challenge to central authority, and the awe that this inspired, means that Izumo holds a special historical and spiritual significance for Japanese. By the middle of the twentieth century, most historians and archeologists were skeptical of the notion that Izumo, in present-day Shimane-ken (prefecture) (Yamato is in present-day Nara-ken), had ever been a locus of power. Most historians agreed that the legend of Izumo resistance had been fabricated as a means of establishing the legitimacy of the imperial clan. The modern-day interpretation was opened to review in 1984, however, with the discovery of the Kojindani ruins in western.
Hangover - Table of contents showTocToggle("show","hide") 1 The Symptoms 2 The Cause 3 The Cures The Symptoms An alcohol hangover is associated with variety of symptoms, including dry mouth, headaches, bloodshot eyes, nausea and vomiting, and sensitivity to light and noise. The Cause Hangovers are multi-causal. Ethyl alcohol has a dehydrating effect, which causes headaches, dry mouth, and lethargy. This can be mitigated by drinking plenty of water between and after the alcoholic consumptions. Alcohol is also a metabolic poison, and its impact on the stomach lining probably accounts for the nausea. Another factor contributing to hangover is the conversion of alcohol to acetaldehyde by the liver. This metabolite is probably more toxic than alcohol. Finally there are various nervous effects. The removal of the depressive effects of alcohol in the brain probably.
Harness racing - must be slowed down and taken to the outside until it regains stride). One of the reasons pacers are less likely to break stride is that they often wear hopples or hobbles, straps which connect the legs on each of the horse's sides. Most harness races start from a motorized gate. The horses line up behind a hinged gate mounted on a motor vehicle which then takes them to the starting line. At the starting line the wings of the gate are folded up and the vehicle accelerates away from the horses. Some European races start without a gate. The sulky (informally known as a bike) is a light two-wheeled cart equipped with bicycle wheels. The driver carries a long, light whip which is chiefly used to signal the horse by.
