text stringlengths 0 73.6k | source stringclasses 4
values |
|---|---|
Variable-frequency drive-System description and operation-Controller The VFD controller is a solid-state power electronics conversion system consisting of three distinct sub-systems: a rectifier bridge converter, a direct current (DC) link, and an inverter. Voltage-source inverter (VSI) drives (see 'Generic topologies'... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-System description and operation-Although space vector pulse-width modulation (SVPWM) is becoming increasingly popular, sinusoidal PWM (SPWM) is the most straightforward method used to vary drives' motor voltage (or current) and frequency. With SPWM control (see Fig. 1), quasi-sinusoidal, varia... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-System description and operation-An embedded microprocessor governs the overall operation of the VFD controller. Basic programming of the microprocessor is provided as user-inaccessible firmware. User programming of display, variable, and function block parameters is provided to control, protec... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-System description and operation-Operator interface The operator interface provides a means for an operator to start and stop the motor and adjust the operating speed. The VFD may also be controlled by a programmable logic controller through Modbus or another similar interface. Additional opera... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-System description and operation-Speed control There are two main ways to control the speed of a VFD; networked or hardwired. Networked involves transmitting the intended speed over a communication protocol such as Modbus, Modbus/TCP, EtherNet/IP, or via a keypad using Display Serial Interface ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Programming a VFD-Depending on the model a VFD's operating parameters can be programmed via: dedicated programming software, internal keypad, external keypad, or SD card. VFDs will often block out most programming changes while running. Typical parameters that need to be set include: motor name... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Starting and software behavior-Most VFDs allow auto-starting to be enabled. Which will drive the output to a designated frequency after a power cycle, or after a fault has been cleared, or after the emergency stop signal has been restored (generally emergency stops are active low logic). One po... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Starting and software behavior-Drive operation Referring to the accompanying chart, drive applications can be categorized as single-quadrant, two-quadrant, or four-quadrant; the chart's four quadrants are defined as follows: Quadrant I – Driving or motoring, forward accelerating quadrant with p... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Starting and software behavior-Certain applications involve two-quadrant loads operating in quadrant I and II where the speed is positive but the torque changes polarity as in case of a fan decelerating faster than natural mechanical losses. Some sources define two-quadrant drives as loads oper... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Starting and software behavior-Certain high-performance applications involve four-quadrant loads (Quadrants I to IV) where the speed and torque can be in any direction such as in hoists, elevators, and hilly conveyors. Regeneration can occur only in the drive's DC link bus when inverter voltage... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Starting and software behavior-With a VFD, the stopping sequence is just the opposite as the starting sequence. The frequency and voltage applied to the motor are ramped down at a controlled rate. When the frequency approaches zero, the motor is shut off. A small amount of braking torque is ava... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Benefits-Energy savings Many fixed-speed motor load applications that are supplied direct from AC line power can save energy when they are operated at variable speed by means of VFD. Such energy cost savings are especially pronounced in variable-torque centrifugal fan and pump applications, whe... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Benefits-In the United States, an estimated 60–65% of electrical energy is used to supply motors, 75% of which are variable-torque fan, pump, and compressor loads. Eighteen percent of the energy used in the 40 million motors in the U.S. could be saved by efficient energy improvement technologie... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Benefits-Variable-speed drives can also run a motor in specialized patterns to further minimize mechanical and electrical stress. For example, an S-curve pattern can be applied to a conveyor application for smoother deceleration and acceleration control, which reduces the backlash that can occu... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Generic topologies AC drives can be classified according to the following generic topologies: Voltage-source inverter (VSI) drive topologies (see image): In a VSI drive, the DC output of the diode-bridge converter stores energy in the capacitor bus to supply stiff voltage ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Six-step inverter drive topologies (see image): Now largely obsolete, six-step drives can be either VSI or CSI type and are also referred to as variable-voltage inverter drives, pulse-amplitude modulation (PAM) drives, square-wave drives or D.C. chopper inverter drives. In... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Load commutated inverter (LCI) drive topologies: In an LCI drive (a special CSI case), the DC output of the SCR-bridge converter stores energy via DC link inductor circuit to supply stiff quasi-sinusoidal six-step current output of a second SCR-bridge's inverter and an ove... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Cycloconverter or matrix converter (MC) topologies (see image): Cycloconverters and MCs are AC-AC converters that have no intermediate DC link for energy storage. A cycloconverter operates as a three-phase current source via three anti-parallel-connected SCR-bridges in six... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Doubly fed slip recovery system topologies: A doubly fed slip recovery system feeds rectified slip power to a smoothing reactor to supply power to the AC supply network via an inverter, the speed of the motor being controlled by adjusting the DC current.
Control platforms ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Available power ratings VFDs are available with voltage and current ratings covering a wide range of single-phase and multi-phase AC motors. Low-voltage (LV) drives are designed to operate at output voltages equal to or less than 690 V. While motor-application LV drives ar... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-VFD types and ratings-Drives by machines and detailed topologies It is lastly useful to relate VFDs in terms of the following two classifications: In terms of various AC machines as shown in Table 1 below In terms of various detailed AC-AC converter topologies shown in Tables 2 and 3 below. | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-AC line harmonics Note of clarification:.While harmonics in the PWM output can easily be filtered by carrier-frequency-related filter inductance to supply near-sinusoidal currents to the motor load, the VFD's diode-bridge rectifier converts AC line voltage to DC volta... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-When the power company's voltage becomes distorted due to harmonics, losses in other loads such as normal fixed-speed AC motors are increased. This condition may lead to overheating and shorter operating life. Also, substation transformers and compensation capacitors ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Two other harmonics mitigation techniques exploit use of passive or active filters connected to a common bus with at least one VFD branch load on the bus. Passive filters involve the design of one or more low-pass LC filter traps, each trap being tuned as required to ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Switching frequency foldback One drive uses a default switching frequency setting of 4 kHz. Reducing the drive's switching frequency (the carrier-frequency) reduces the heat generated by the IGBTs.A carrier frequency of at least ten times the desired output frequency ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Noise smoothing Some drives have a noise smoothing feature that can be turned on to introduce a random variation to the switching frequency. This distributes the acoustic noise over a range of frequencies to lower the peak noise intensity. | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Long-lead effects The carrier-frequency pulsed output voltage of a PWM VFD causes rapid rise times in these pulses, the transmission line effects of which must be considered. Since the transmission-line impedance of the cable and motor are different, pulses tend to re... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Motor bearing currents Carrier frequencies above 5 kHz are likely to cause bearing damage unless protective measures are taken.PWM drives are inherently associated with high-frequency common-mode voltages and currents which may cause trouble with motor bearings. When ... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Dynamic braking Torque generated by the drive causes the induction motor to run at synchronous speed less the slip. If the load drives the motor faster than synchronous speed, the motor acts as a generator, converting mechanical power back to electrical power. This po... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Regenerative drives Regenerative AC drives have the capacity to recover the braking energy of a load moving faster than the designated motor speed (an overhauling load) and return it to the power system. | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-Cycloconverter, Scherbius, matrix, CSI, and LCI drives inherently allow return of energy from the load to the line, while voltage-source inverters require an additional converter to return energy to the supply.Regeneration is useful in VFDs only where the value of the... | milkshake721/2.1M-wiki-STEM |
Variable-frequency drive-Application considerations-A crane, where the hoist motor stops and reverses frequently, and braking is required to slow the load during lowering.
Plug-in and hybrid electric vehicles of all types (see image and Hybrid Synergy Drive). | milkshake721/2.1M-wiki-STEM |
Jury rigging-Jury rigging-In maritime transport terms, and most commonly in sailing, jury-rigged is an adjective, a noun, and a verb. It can describe the actions of temporary makeshift running repairs made with only the tools and materials on board; and the subsequent results thereof. The origin of jury-rigged and jury... | milkshake721/2.1M-wiki-STEM |
Jury rigging-Jury rigging-Similarly, after a dismasting, a replacement mast, often referred to as a jury mast (and if necessary, yard) would be fashioned, and stayed to allow a watercraft to resume making way. | milkshake721/2.1M-wiki-STEM |
Jury rigging-Etymology-The phrase 'jury-rigged' has been in use since at least 1788. The adjectival use of 'jury', in the sense of makeshift or temporary, has been said to date from at least 1616, when according to the 1933 edition of the Oxford Dictionary of the English Language, it appeared in John Smith's A Descript... | milkshake721/2.1M-wiki-STEM |
Jury rigging-Etymology-From the Latin adjutare: 'to aid'; via Old French ajurie: 'help' or 'relief'. | milkshake721/2.1M-wiki-STEM |
Jury rigging-Rigging-Depending on its size and purpose, a sail-powered boat may carry a limited amount of repair materials, from which some form of jury-rig can be fashioned. Additionally, anything salvageable, such as a spar or spinnaker pole, could be adapted to carrying a form of makeshift sail. | milkshake721/2.1M-wiki-STEM |
Jury rigging-Rigging-Ships typically carried a selection of spare parts, e.g., items such as topmasts. However, due to their much larger size, at up to 1 metre (3 ft 3 in) in diameter, the lower masts were too large to carry as spares. Example jury-rig configurations include: A spare topmast The main boom of a brig Rep... | milkshake721/2.1M-wiki-STEM |
Jury rigging-Similar phrases-The compound word 'jerry-built', a similar but distinct term, referring to things 'built unsubstantially of bad materials', has a separate origin from jury-rigged. The exact etymology is unknown, but it is probably linked to earlier pejorative uses of the word 'jerry', attested as early as ... | milkshake721/2.1M-wiki-STEM |
Jury rigging-Similar phrases-The American terms 'Afro engineering' (short for African engineering) or 'nigger-rigging' describes a fix that is temporary, done quickly, technically improperly, or without attention to or care for detail. It can also describe shoddy, second-rate workmanship, with whatever materials happen... | milkshake721/2.1M-wiki-STEM |
Jury rigging-Similar phrases-To 'MacGyver' (or MacGyverize) something is to rig up something in a hurry using materials at hand, from the title character of the American television show of the same name, who specialized in such improvisation stunts.
In New Zealand, having a 'Number 8 wire' mentality means to have the a... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Corey–House synthesis-The Corey–House synthesis (also called the Corey–Posner–Whitesides–House reaction and other permutations) is an organic reaction that involves the reaction of a lithium diorganylcuprate ( CuLi ) with an organic halide or pseudohalide ( R′−X ) to form a new alkane, as well as ... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Corey–House synthesis-Li Cu Cu LiX In principle, a carbanion equivalent such as an organolithium or Grignard reagent can react directly (without copper) with an alkyl halide in a nucleophilic substitution reaction to form a new carbon–carbon bond. However, aside from the use of metal acetylides as... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Scope-The scope of the Corey-House synthesis is exceptionally broad, and a range of lithium diorganylcuprates (R2CuLi, R = 1°, 2°, or 3° alkyl, aryl, or alkenyl) and organyl (pseudo)halides (RX, R = methyl, benzylic, allylic, 1°, or cyclic 2° alkyl, aryl, or alkenyl and X = Br, I, OTs, or OTf; X =... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Reaction process and mechanism-The Corey-House synthesis is preceded by two preliminary steps to prepare the requisite Gilman reagent from an alkyl halide. In the first step, the alkyl halide is treated with lithium metal in dry ether to prepare an alkyllithium reagent, RLi. The starting alkyl hal... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Reaction process and mechanism-It is important to note that when R and R' are different, only the cross product R–R' is obtained; R–R or R'–R' are not formed in significant amounts. The Corey–House reaction is therefore an example of a cross-coupling reaction. The Corey–House synthesis is, in fact... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Reaction process and mechanism-It is important to note that for this reaction to work successfully, the alkyl (pseudo)halide coupling partner should be methyl, benzylic, allylic, 1° alkyl, or 2° cycloalkyl. In most cases, 3° and acyclic 2° electrophiles give unsatisfactory results. (However, see b... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Catalytic version-In 1971, Jay Kochi reported that Grignard reagents and alkyl bromides could be coupled using a catalytic amount of lithium tetrachlorocuprate(II), a process that was extended to alkyl tosylates by Schlosser and Fouquet. In the catalytic process, the Grignard reagent undergoes tra... | milkshake721/2.1M-wiki-STEM |
Corey–House synthesis-Background-While the coupling of organocopper compounds and allyl bromide was reported as early as 1936 by Henry Gilman (Iowa State University), this reaction was fully developed by four organic chemists (two at Harvard and two at MIT): E.J. Corey (Harvard University), research advisor of Gary Po... | milkshake721/2.1M-wiki-STEM |
Paper soccer-Paper soccer-Paper soccer (or paper hockey) is an abstract strategy game played on a square grid representing a soccer or hockey field. Two players take turns extending a line representing the position of a ball until it reaches one of the grid's two-goal spaces. A traditional paper-and-pencil game, it is ... | milkshake721/2.1M-wiki-STEM |
Paper soccer-General rules-The game's pitch is drawn as a rectangle on a grid, with small extended rectangles in the center of each of the two shortest sides to represent the two goalposts. The grid can be of any size, although both sides should be an even number of squares to allow a center point for kickoff. The goal... | milkshake721/2.1M-wiki-STEM |
Paper soccer-General rules-A "ball" is marked as a dot in the center of the pitch. Players alternately move the ball to a new point by drawing a line from its current position to a new one. Each move must be to a point orthogonally or diagonally adjacent. The ball cannot be moved beyond the boundary of the pitch, nor a... | milkshake721/2.1M-wiki-STEM |
Paper soccer-General rules-If the ball is moved to a point that already has one or more lines connected to it, including the perimeter of the pitch, the ball "bounces" and the player immediately takes another turn. The player's move ends only when the ball reaches a point with no existing lines. | milkshake721/2.1M-wiki-STEM |
Paper soccer-General rules-The winner is the player who places the ball in their opponent's goal. A player also wins if their opponent scores an own goal. If the ball reaches a point from which it cannot be moved (such as a corner of the pitch) this is regarded as a draw, or a loss for the player unable to move, depend... | milkshake721/2.1M-wiki-STEM |
Paper soccer-General rules-Variants and modifications The players can regulate the pitch's shape in various ways by altering the pitch's dimensions or the placement of the gates. In some variants, one or more special lines may be added to the pitch. This modification is found in computer applications, and expanded vari... | milkshake721/2.1M-wiki-STEM |
Paper soccer-General rules-Another variant allows a player to make a "bounce" during any turn if the line of that bounce would cross an existing diagonal line.Another variant is Texas Soccer which allows no "X" marks to be made as the ball can no longer cross through a diagonal line. | milkshake721/2.1M-wiki-STEM |
Paper soccer-Strategy-Since the ball's movement cannot overlap previously drawn lines, a player can block their opponent's potential moves by filling strategic points on the board and limiting the mobility of their opponent. Another strategy is based on the use of "bounces" for streamlining mobility, which can greatly ... | milkshake721/2.1M-wiki-STEM |
Paper soccer-Game notation-Each move in the game may be recorded as a string of one or more digits from 0 to 7, each digit representing the direction of a move (with 0 corresponding to 'north', 1 to 'north-east', 2 to 'east' and so on) across a single grid. Multiple digits are used to record bounce moves. This notation... | milkshake721/2.1M-wiki-STEM |
Paper soccer-Similar games-There are two similar games that imitate paper soccer. Their mechanisms also depend on drawing lines to describe a ball's movement on a field. | milkshake721/2.1M-wiki-STEM |
Paper soccer-Similar games-Paper soccer (Russian variant) This paper-and-pencil game also involves drawing lines to adjacent points on a grid and is distinguished by a larger play area and players extending the line to three points each turn. The line can change direction at each point but must not touch any existing l... | milkshake721/2.1M-wiki-STEM |
Paper soccer-Similar games-The strategy involves blocking an opponent's potential moves, outmaneuvering the opponent at the edges of the field, and setting traps for penalty kicks in range of the opponent's goal. If a trap is not executed successfully, the opponent may be able to reverse it in an extreme move.The game ... | milkshake721/2.1M-wiki-STEM |
Paper soccer-Similar games-xrSoccer Published in 2005, xrSoccer is a computer game by eXtreme Results International Inc. It may be adapted to paper-and-pencil form for two players. It has common features with the previously described versions of paper soccer but gameplay generally differs. | milkshake721/2.1M-wiki-STEM |
Paper soccer-Similar games-The pitch is a 14 × 20 grid (13 × 19 points) with goal gates on the shorter sides. Starting from the center point, the line is extended to three points per turn. The line can touch occupied points and cross existing lines (there are no bounce moves) but cannot move along an existing line. If ... | milkshake721/2.1M-wiki-STEM |
Song bells-Song bells-Song bells are a musical instrument in the keyboard percussion family. They are a mallet percussion instrument in the metallophone family that is essentially a cross between the vibraphone, glockenspiel, and celesta. They have bars made of aluminum.They sound one octave down from the glockenspiel,... | milkshake721/2.1M-wiki-STEM |
2,2'-Dipyrromethene-2,2'-Dipyrromethene-2,2'-Dipyrromethene, often called just dipyrromethene or dipyrrin, is a chemical compound with formula C9H8N2 whose skeleton can be described as two pyrrole rings C5N connected by a methyne bridge =CH– through their nitrogen-adjacent (position-2) carbons; the remaining bonds bein... | milkshake721/2.1M-wiki-STEM |
2,2'-Dipyrromethene-Preparation-2,2'-Dipyrromethene and its derivatives can be obtained from suitable pyrrole derivatives by several methods.The unsubstituted compound can be prepared by oxidation of 2,2'-dipyrrolemethane with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) at −78 °C in dry dichloromethane solution. An... | milkshake721/2.1M-wiki-STEM |
2,2'-Dipyrromethene-Preparation-Alternatively, one may use an activated carboxylic acid derivative, usually an acyl chloride. As another possibility, one may condense a substituted pyrroles with a 2-acylpyrrole; this route allows the synthesis of unsymmetrical dipyrromethenes. | milkshake721/2.1M-wiki-STEM |
2,2'-Dipyrromethene-Reactions-Dipyrrin is unstable above −40 °C. However, its acts as a base, and its chloride [C9H9N+2] [Cl−] is sufficiently stable in solution.The so-called BODIPY dyes can be obtained by reacting 2,2'-dipyrromethene or its derivatives with boron trifluoride-diethyl ether complex (BF3·(C2H5)2O) in th... | milkshake721/2.1M-wiki-STEM |
Mannosyl-3-phosphoglycerate synthase-Mannosyl-3-phosphoglycerate synthase-In enzymology, a mannosyl-3-phosphoglycerate synthase (EC 2.4.1.217) is an enzyme that catalyzes the chemical reaction GDP-mannose + 3-phospho-D-glycerate ⇌ GDP + 2-(alpha-D-mannosyl)-3-phosphoglycerateThus, the two substrates of this enzyme are... | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Winter sports in Slovakia-Ski and winter sports in Slovakia are very prominent and popular given the mountainous topography of the region and the fact that much of the country is covered by snow for a long part of the year. | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Downhill Skiing-In spite of its small area, which is mostly hilly, Slovakia is densely interwoven by a net of ski-tows and ski-lifts. More than 1000 ski-tows and 40 ski-lifts are in operation and their number is growing. From the top the terminal stations there are hundreds of down-hill pistes... | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Downhill Skiing-At present, approximately 50 Slovak ski resorts make snow. | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Snowboarding-Snowboarding is the fastest developing winter sport in the world. Slovakia is no exception - the number of snowboarders has been increasing every year, partly due to the type of terrain available in ski resorts. Well equipped board parks at the larger resorts offer excellent jumps... | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Ski-Alpinism-Ski-alpinism is a combination of cross-country skiing, mountaineering and alpine skiing. Its fans seek new opportunities for testing own stamina and strength in the extreme conditions of winter alpine nature. The Slovak mountains provide very good conditions for pursuing this spor... | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Cross-country skiing-Bigger ski resorts offer well kept cross-country paths, but skier made paths can be found virtually by any village or tourist centre. Slovakia is rather small, so there is not much of "cross country". | milkshake721/2.1M-wiki-STEM |
Winter sports in Slovakia-Ski jumping-Ski jumping is not a popular sport in Slovakia. However, some jumping hills exist.[1] | milkshake721/2.1M-wiki-STEM |
Apical dominance-Apical dominance-In botany, apical dominance is the phenomenon whereby the main, central stem of the plant is dominant over (i.e., grows more strongly than) other side stems; on a branch the main stem of the branch is further dominant over its own side twigs.
Plant physiology describes apical dominance... | milkshake721/2.1M-wiki-STEM |
Apical dominance-Overview-Apical dominance occurs when the shoot apex inhibits the growth of lateral buds so that the plant may grow vertically. It is important for the plant to devote energy to growing upward so that it can get more light to undergo photosynthesis. If the plant utilizes available energy for growing up... | milkshake721/2.1M-wiki-STEM |
Apical dominance-Overview-Typically, the end of a shoot contains an apical bud, which is the location where shoot growth occurs. The apical bud produces a plant hormone, auxin, (IAA) that inhibits growth of the lateral buds further down on the stem towards the axillary bud. Auxin is predominantly produced in the growin... | milkshake721/2.1M-wiki-STEM |
Apical dominance-Apex removal-Plant physiologists have identified four different stages the plant goes through after the apex is removed (Stages I-IV). The four stages are referred to as lateral bud formation, "imposition of inhibition" (apical dominance), initiation of lateral bud outgrowth following decapitation, an... | milkshake721/2.1M-wiki-STEM |
Apical dominance-Applications-When the apical bud is removed, the lowered IAA concentration allows the lateral buds to grow and produce new shoots, which compete to become the lead growth. Pruning techniques such as coppicing and pollarding make use of this natural response to curtail direct plant growth and produce a ... | milkshake721/2.1M-wiki-STEM |
Apical dominance-Applications-Some fruit trees have strong apical dominance, and young trees can become "leggy", with poor side limb development. Apical dominance can be reduced in this case, or in cases where limbs are broken off by accident, by cutting off the auxin flow above side buds that one wishes to stimulate. ... | milkshake721/2.1M-wiki-STEM |
Bingo card-Bingo card-Bingo cards are playing cards designed to facilitate the game of Bingo in its various forms around the world. | milkshake721/2.1M-wiki-STEM |
Bingo card-History-In the early 1500s the people of Italy began to play a game called "Lo Gioco del Lotto d'Italia," which literally means "The game of lotto of Italy." The game operated very much like a modern lottery as players placed bets on the chances of certain numbers being drawn. By the 1700s, a version of Lo G... | milkshake721/2.1M-wiki-STEM |
Bingo card-Types of cards-There are two types of Bingo cards. One is a 5x5 grid meant for 75-ball Bingo, which is largely played in the U.S. The other uses a 9x3 grid for U.K. style "Housie" or 90-ball Bingo.
75-ball bingo cards Players use cards that feature five columns of five squares each, with every square contain... | milkshake721/2.1M-wiki-STEM |
Bingo card-Types of cards-The calculation of random permutations is a matter of statistics principally relying on the use of factorial calculations. In its simplest sense, the number of unique "B" columns assumes that all 15 numbers are available for the first row. That only 14 of the numbers are available for the seco... | milkshake721/2.1M-wiki-STEM |
Bingo card-Types of cards-Printing a complete set of Bingo cards is impossible for all practical purposes. If one trillion cards could be printed each second, a printer would require more than seventeen million years to print just one set. However, while the number combination of each card is unique, the number of winn... | milkshake721/2.1M-wiki-STEM |
Bingo card-Types of cards-For example, in a simple one-pattern game of Bingo a winning card may be the first person to complete row #3. Because the "N" column contains a free space, the maximum number of cards that guarantee a unique winner is (15*15*15*15) = 50,625. Because the players need to only focus on row #3, th... | milkshake721/2.1M-wiki-STEM |
Bingo card-Types of cards-Perhaps the most common pattern set, known as "Straight-line Bingo" is completing any of the five rows, columns, or either of the main diagonals. In this case the possibility of multiple winning cards is unavoidable because any one of twelve patterns on every card can win the game. But not all... | milkshake721/2.1M-wiki-STEM |
Bingo card-Types of cards-90-ball bingo cards In UK bingo, or Housie, cards are usually called "tickets." The cards contain three rows and nine columns. Each row contains five numbers and four blank spaces randomly distributed along the row. Numbers are apportioned by column (1–9, 10–19, 20–29, 30–39, 40–49, 50–59, 60–... | milkshake721/2.1M-wiki-STEM |
P57 (glycoside)-P57 (glycoside)-P57 is an oxypregnane steroidal glycoside isolated from the African cactiform Hoodia gordonii. P57 is hypothesized to be the chemical constituent from this plant mainly responsible for the putative appetite suppressant activity of Hoodia extracts.In a rat study at Brown Medical School, i... | milkshake721/2.1M-wiki-STEM |
P57 (glycoside)-P57 (glycoside)-The studies demonstrated that the compound increases the content of ATP by 50-150% in hypothalamic neurons. In addition, third ventricle administration of P57 reduced subsequent 24-hour food intake by 40-60%. | milkshake721/2.1M-wiki-STEM |
Thymine-DNA glycosylase-Thymine-DNA glycosylase-G/T mismatch-specific thymine DNA glycosylase is an enzyme that in humans is encoded by the TDG gene. Several bacterial proteins have strong sequence homology with this protein. | milkshake721/2.1M-wiki-STEM |
Thymine-DNA glycosylase-Function-The protein encoded by this gene belongs to the TDG/mug DNA glycosylase family. Thymine-DNA glycosylase (TDG) removes thymine moieties from G/T mismatches by hydrolyzing the carbon-nitrogen bond between the sugar-phosphate backbone of DNA and the mispaired thymine. With lower activity, ... | milkshake721/2.1M-wiki-STEM |
Thymine-DNA glycosylase-Interactions-Thymine-DNA glycosylase has been shown to interact with: CREB-binding protein, Estrogen receptor alpha, Promyelocytic leukemia protein, SUMO3, and Small ubiquitin-related modifier 1. | milkshake721/2.1M-wiki-STEM |
Thymine-DNA glycosylase-Interactive pathway map-Click on genes, proteins and metabolites below to link to respective articles. | milkshake721/2.1M-wiki-STEM |
Gel conference-Gel conference-Gel (Good Experience Live) is a conference focused on the concept of a "good experience" in all contexts – business, art, society, technology, and life.
The conference has been held annually in New York City since 2003, and the first European counterpart, euroGel 2006, took place in Copenh... | milkshake721/2.1M-wiki-STEM |
Band matrix-Band matrix-In mathematics, particularly matrix theory, a band matrix or banded matrix is a sparse matrix whose non-zero entries are confined to a diagonal band, comprising the main diagonal and zero or more diagonals on either side. | milkshake721/2.1M-wiki-STEM |
Band matrix-Band matrix-Bandwidth Formally, consider an n×n matrix A=(ai,j ). If all matrix elements are zero outside a diagonally bordered band whose range is determined by constants k1 and k2: if or 0.
then the quantities k1 and k2 are called the lower bandwidth and upper bandwidth, respectively. The bandwidth of th... | milkshake721/2.1M-wiki-STEM |
Band matrix-Examples-A band matrix with k1 = k2 = 0 is a diagonal matrix A band matrix with k1 = k2 = 1 is a tridiagonal matrix For k1 = k2 = 2 one has a pentadiagonal matrix and so on.
Triangular matrices For k1 = 0, k2 = n−1, one obtains the definition of an upper triangular matrix similarly, for k1 = n−1, k2 = 0 one... | milkshake721/2.1M-wiki-STEM |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.