Hole Accumulation Diode HAD is a patented technique of the Sony Corporation to reduce electronic noise in a Charge coupled device CCD or CMOS imaging sensor by reducing the so called dark current that occur in the absence of light falling on the imager for noise reduction and enhanced image quality. The hole refers to places in a semiconductor where an electron has been dislodged, thus creating a positive charge. These holes or positive charges can be created by heat or imperfections in the creation of the imaging chip. The holes are accumulated, or trapped, in a separate semiconductor layer that acts as a diode that prevents them from returning or creating noise. HAD technology suppresses the fixed pattern noise that results from dark current that occurs regardless of the amount of absorbed light. By fabricating a hole accumulation layer below the surface of the CCD, dark current can be suppressed at the source. HAD CCDs are used in consumer and professional single, as well as, three chip video camera s. External links http www.sony.net SonyInfo News Press Archive 200002 00 007 Sony Press Release Category Image sensors Category Diodes ... more details
Unreferenced date February 2007 Wills, trusts, estates Accumulation and maintenance A&M trusts are a type of discretionary trust for the benefit of children and young people in England and Wales. Development and tax treatment The concept of an A&M trust emerged in England and Wales after the enactment of the Capital Taxes Act 1974 CTA . The CTA discouraged the use of discretionary trusts by introducing new tax rules, but it made a specific exception for trusts designed to help young people under the age of 25 . This particular type of trust grew in significance over the years and became known as an Accumulation & Maintenance Trust. They came to fall under the purview of s.71 Inheritance Tax Act 1984 IHTA , which continued their special tax treatment The Finance Act 2006 took A&M Trusts out of the purview of s.71. Today, A&M Trusts are governed by Pt. III, Ch. III IHTA, and therefore receive exactly the same tax treatment as other types of discretionary trusts. As a result, the use of A&M trusts is declining rapidly. The new breed of 18 25 trusts are taking their place. Category Wills and trusts ... more details
In mathematics , differential topology is the field dealing with differentiable function s on differentiable manifold s. It is closely related to differential geometry and together they make up the geometric theory of differentiable manifolds. Description Differential topology considers the properties ... types of equivalences and deformations that exist in differential topology. For instance, volume and Riemannian .... One of the main topics in differential topology is the study of special kinds of smooth mappings ... , another special kind of smooth mapping. Morse theory is another branch of differential topology, in which topological information about a manifold is deduced from changes in the rank differential ... of differential topology topics, see the following reference List of differential geometry topics . Differential topology versus differential geometry details geometry and topology Differential topology and differential geometry are first characterized by their similarity . They both study primarily ... view, ref Hirsch 1997 ref differential topology distinguishes itself from differential geometry by studying ... morph.gif this example span . From the point of view of differential topology, the donut and the coffee ... for the differential topologist to tell whether the two objects are the same in this sense by looking ... the point of view of differential geometry, the coffee cup and the donut are different because ... is thinner or more curved than any piece of the donut. To put it succinctly, differential topology studies structures on manifolds which, in a sense, have no interesting local structure. Differential ... that it is already exhibited in the topology of R sup n sup . Moreover, differential topology ... &mdash a subbranch of differential topology &mdash studies global properties of symplectic manifold s. Differential geometry concerns itself with problems &mdash which may be local or global &mdash that always have some non trivial local properties. Thus differential geometry may study differentiable ... more details
and being cooled at the boundary, providing a steady state temperature distribution. A differential ... and its derivative s of various orders. Differential equations play a prominent role in engineering , physics , economics , and other disciplines. Differential equations arise in many areas of science ... forces acting on the body to express these variables dynamically as a differential equation for the unknown position of the body as a function of time. In some cases, this differential equation ... world problem using differential equations is the determination of the velocity of a ball falling .... Finding the velocity as a function of time involves solving a differential equation. Differential equations ... the set of functions that satisfy the equation. Only the simplest differential equations admit solutions given by explicit formulas however, some properties of solutions of a given differential ... of dynamical systems puts emphasis on qualitative analysis of systems described by differential equations ... of accuracy. Directions of study The study of differential equations is a wide field in pure mathematics ... are concerned with the properties of differential equations of various types. Pure mathematics focuses ... justification of the methods for approximating solutions. Differential equations play an important ..., to bridge design, to interactions between neurons. Differential equations such as those used to solve ... closed form solutions. Instead, solutions can be approximated using Numerical ordinary differential ... of the stability of solutions of differential equations is known as stability theory . Nomenclature The theory of differential equations is quite developed and the methods used to study them vary significantly with the type of the equation. An ordinary differential equation ODE is a differential equation ... valued or matrix mathematics matrix valued this corresponds to considering a system of ordinary differential equations for a single function. anchor first order differential equation second order differential ... more details
expert subject Physical Chemistry date January 2011 An inexact differential or imperfect differential is a specific type of Differential infinitesimal differential used in thermodynamics to express the path dependence of a particular differential. It is contrasted with the concept of the exact differential in calculus , which can be expressed as the gradient of another function and is therefore path independent. Consequently, an inexact differential cannot be expressed in terms of its antiderivative ... functions . Definition An inexact differential is commonly defined as a differential form ... differential is a differential form that cannot be expressed as the differential of a function. In the language of calculus, for a given vector field F, math delta F F , dr math is an inexact differential ... energy &Delta U . Examples Although difficult to express mathematically, the inexact differential is very ... idea behind the inexact differential. There are many everyday examples that are much more relevant ... form of energy transform. Therefore, the sum of exchanged heat and work is an exact differential ... an inexact differential into an exact one by means of an integrating factor . The most common example ... In this case, Q is an inexact differential, because its effect on the state of the system can ... occurs at reversible conditions therefore the sub rev sub subscript , it produces an exact differential the entropy S is also a state function. See also Closed and exact differential forms for a higher level treatment Differential mathematics Exact differential Integrating factor for solving non exact differential equations by making them exact References reflist External links http mathworld.wolfram.com InexactDifferential.html Inexact Differential from Wolfram MathWorld http www.chem.arizona.edu ... of Texas http mathworld.wolfram.com ExactDifferential.html Exact Differential from Wolfram MathWorld DEFAULTSORT Inexact Differential Category Thermodynamics Category Multivariable calculus pl R niczka ... more details
. Differential geometry is a mathematics mathematical discipline that uses the techniques of differential ... problems in geometry . The theory of plane and space differential geometry of curves curves and of differential ... for development of differential geometry during the 18th century and the 19th century . Since the late 19th century, differential geometry has grown into a field concerned more generally with the geometric structures on differentiable manifold s. Differential geometry is closely related to differential topology , and to the geometric aspects of the theory of differential equation s. Grigori Perelman ... of the differential geometric approach to questions in topology and it highlighted the important role played by its analytic methods. The differential geometry of surfaces captures many of the key ideas and techniques characteristic of this field. Branches of differential geometry Riemannian geometry ... of analysis and differential equations have been generalized to the setting of Riemannian manifolds ... as the main object of study. This is a differential manifold with a Finsler metric , i.e. a Banach ... on each tangent space, i.e., a nondegenerate 2 Differential form form , called the symplectic form ... each point p , a hyperplane distribution is determined by a nowhere vanishing Differential form 1 form ... differential geometry is the study of complex manifolds . An almost complex manifold is a real manifold ... Hermitian structure defines naturally a differential form differential two form math omega J,g X ... of the intrinsic geometry of boundaries of domains in complex manifold s. Differential topology Differential topology is the study of global geometric invariants without a metric or symplectic form ... derivative de Rham differential of Differential form forms . Beside Lie algebroid s, also Courant ... in the category of smooth manifolds. Beside the algebraic properties this enjoys also differential ... connection s on bundles plays an extraordinarily important role in modern differential geometry ... more details
Differential display also referred to as DDRT PCR or DD PCR is the technique where a researcher can compare and identify changes in gene expression at the mRNA level between any pair of eukaryotic cell samples. The assay may be extended to more than one pair, if needed. The paired samples will have morphological, genetic or other experimental differences for which the researcher wishes to study the gene expression patterns, hoping to elucidate the root cause of the particular difference or specific genes that are affected by the experiment. The concept of differential display is to use a limited number of short arbitrary primers in combination with the anchored oligo dT primers to systematically amplify and visualize most of the mRNA in a cell. Since its invention in the early 1990s, differential display has become one of the most commonly used techniques for identifying differentially expressed genes at the mRNA level. Different streamlined DD PCR protocols have been proposed including fluorescent DD process as well as radioactive labeling, which offers high accuracy and readout. In the mid 2000 s, differential display and RNAse protection assay were superseeded by DNA Microarrays , RNA seq and qRT PCR . References 1. Liang, P. & Pardee, A.B. Differential display of eukaryotic messenger RNA by means of the polymerase chain reaction. Science 257, 967 971 1992 . 2. Liang, P. A decade of differential display. Biotechniques 33, 338 346 2002 . 3. Liang, P. & Pardee, A.B. Analysing differential gene expression in cancer. Nat. Rev. Cancer 3, 869 876 2003 . ikl DEFAULTSORT Differential Display Category Biotechnology ar ... more details
In United States federal milk marketing orders , the fluid differential or Class I differential is the amount added to the base price of milk to determine a region s minimum price for milk used for fluid drinking purposes. References CRS article Report for Congress Agriculture A Glossary of Terms, Programs, and Laws, 2005 Edition url http ncseonline.org nle crsreports 05jun 97 905.pdf author Jasper Womach Category United States Department of Agriculture ... more details
In digital communications , differential coding is a technique used to provide unambiguous signal reception when using some types of modulation . It makes data to be transmitted to depend not only on the current bit or symbol , but also on the previous one. The common types of modulation that require differential coding include phase shift keying and quadrature amplitude modulation . Purposes of differential coding To demodulate BPSK one needs to make a local oscillator synchronous with the remote ... will always be correct. The line code s with this property include differential Manchester encoding ... differential coding Image Differential coding encoder.png right thumb A differential encoder Image Differential coding decoder.png right thumb A differential decoder A method illustrated above can ... synchronization frame synchronizer and sometimes it isn t. Generally speaking, a differential coding ... are used, and triplets of bits are used to resolve 45 ambiguity e.g. in 8PSK . A differential encoder provides the math 1 math operation, a differential decoder the math 2 math operation. Both differential encoder and differential decoder are discrete LTI system linear time invariant systems . The former ... impulse response FIR . They can be analyzed as digital filter s. A differential encoder is similar to an analog ... if k 0 end cases math and a transfer function math H z frac 1 1 z 1 . math A differential decoder ... numbers are equivalent. Generalized differential coding Using the relation math y i 1 oplus x i y i math is not the only way of carrying out differential encoding. More generally, it can be any function ... for any math y 0 math and math u 0 math . Applications Differential coding is widely used in satellite ... keying PSK and QAM modulations. Drawbacks Differential coding has one significant drawback it leads ..., two incorrect symbols math x i math and math x i 1 math would be at the differential decoder s output .... Other techniques to resolve a phase ambiguity Differential coding is not the only way to deal ... more details
In mathematics , a differential invariant is an invariant theory invariant for the group action action of a Lie group on a space that involves the derivative s of graphs of functions in the space. Differential invariants are fundamental in projective differential geometry , and the curvature is often studied from this point of view. ref harvnb Guggenheimer 1977 ref Differential invariants were introduced in special cases by Sophus Lie in the early 1880s and studied by Georges Henri Halphen at the same time. harvtxt Lie 1884 was the first general work on differential invariants, and established the relationship between differential invariants, invariant differential equation s, and invariant differential operator s. Differential invariants are contrasted with geometric invariants. Whereas differential ... less general than Lie s methods of differential invariants, always yields invariants of the geometrical kind. Definition The simplest case is for differential invariants for one independent variable ..., on the space of all graphs of the form y &fnof x . Roughly speaking, a k th order differential ..., differential invariants can be considered for mappings from any smooth manifold X into another ... th order contact. A differential invariant is a function on Y sup k sup that is invariant under the prolongation of the group action. Applications Differential invariants can be applied to the study of systems of partial differential equations seeking similarity solution s that are invariant under ... 1994 loc Chapter 3 ref Noether s theorem implies the existence of differential invariants corresponding ... Guggenheimer title Differential Geometry publisher Dover Publications location New York isbn ... Hermann last2 R title Sophus Lie s 1884 Differential Invariant Paper publisher Math Sci Press publication ... groups to differential equations publisher Springer Verlag location Berlin, New York edition 2nd ... Invariant Variation Problems Category Differential geometry Category Invariant theory Category Projective ... more details
A locking differential , diff lock or locker is a variation on the standard automotive differential mechanics differential . A locking differential may provide increased traction engineering traction compared to a standard, or open differential by restricting each of the two wheels on an axle to the same ... wheel. A locking differential is designed to overcome the chief limitation of a standard open differential ... individually. When the differential is unlocked open differential , it allows each wheel to rotate at different ... of the merry go round , thus avoiding tire scuffing. An open or unlocked differential ..., a locked differential forces both left and right wheels on the same axle to rotate at the same ... apply to automatic lockers, discussed below. A locked differential can provide a significant traction advantage over an open differential, but only when the traction under each wheel differs significantly ... input from the driver. Some automatic locking differential designs ensure that engine power ... wheel to spin slower than the differential carrier or axle as a whole, but will permit a wheel to be over ... Detroit Locker, also known as the Detroit No Spin, which replaces the entire differential carrier assembly. Others, sometimes referred to as Lunchbox locker lunchbox lockers , employ the stock differential ... types of automatic lockers will allow for a degree of differential wheel speed while turning corners ... oversteer when traction is exceeded. Some other automatic lockers operate as an open differential until ... Lok. Some other automatic lockers operate as an open differential until high torque is applied and then they lockup ... lockers allow the driver to lock and unlock the differential at will from the driver s seat. This can ... ford super duty electric locker lowdown index.html ref Pros Allows the differential to perform as an open differential for improved driveability, maneuverability, provides full locking capability when .... Unskilled drivers often put massive stress on driveline components when leaving the differential ... more details
Differential hardening is a method used in forging sword s and knife knives to increase the hardness of the edge without making the whole blade brittle . To achieve this, the edge is cooled more rapidly than the spine by adding a heat insulator to the spine before quenching . Clay or another material is used for insulation. It can also be achieved by carefully pouring water perhaps already heated onto the edge of a blade as is the case with the manufacture of some kukri . Differential hardening technology was perfected in China and later spread to Korea and Japan. This technique is mainly used in the Chinese jian and the katana , the traditional Japan ese sword, and the khukuri , the traditional Nepal ese knife. Most blades made with this technique have visible temper lines. Another process, often referred to as differential hardening, but in reality differential tempering can also be obtained by quenching the object uniformly, then differentially tempering one part of it with a torch or some other directed heat source. The heated portion of the metal is softened by this process. http www.primitiveways.com pt knives 1.html See also Case hardening Shot peening External links http www.engnath.com claytemp.htm Claying blades Differential hardening with clay Category Metal heat treatments metalworking stub ... more details
Differential Staining is a general term that can refer to a number of specific processes. Generally, it is used to describe staining processes which use more than one chemical stain . Using multiple stains can better differentiate between different microorganisms or structures cellular components of a single organism. Differential Staining also describes medical process used to detect abnormalities in the proportion of different white blood cells in the blood . The process or results are called a WBC differential. This test is useful because many diseases alter the proportion of certain white blood cells . By analyzing these differences in combination with a clinical exam and other lab tests, medical professionals can diagnose disease. One commonly recognizable use of differential staining is the Gram stain . Gram staining uses two dyes Crystal violet and Fuchsin the counterstain to differentiate between Gram positive bacteria large Peptidoglycan layer on outer surface of cell and Gram negative bacteria. Further reading http www.mansfield.ohio state.edu sabedon black03.htm differential stain Detailed Overview of staining http www.uphs.upenn.edu bugdrug antibiotic manual Gram2.htm The Gram Stain Technique Category Medical tests pathology stub pt Colora o diferencial ... more details
In mathematics, differential inclusions are a generalization of the concept of ordinary differential equation of the form math frac dx dt t in F t,x t , math where F t , x is a set rather than a single point in math scriptstyle Bbb R d math . Differential inclusions arise in many situations including differential variational inequality differential variational inequalities , projected dynamical system s, dynamic Coulomb friction problems and fuzzy set arithmetic. For example, the basic rule for Coulomb friction is that the friction force has magnitude N in the direction opposite to the direction of slip, where N is the normal force and is a constant the friction coefficient . However, if the slip is zero, the friction force can be any force in the correct plane with magnitude smaller than or equal to N Thus, writing the friction force as a function of position and velocity leads to a set valued function. Theory Existence theory usually assumes that F t , x is an hemicontinuous upper semi continuous function of x , measurable in t , and that F t , x is a closed, convex set for all t and x . Existence of solutions for the initial value problem math frac dx dt t in F t,x t , quad x t 0 x 0 math for a sufficiently small time interval t sub 0 sub , t sub 0 sub , 0 then follows. Global existence can be shown provided F does not allow blow ... math scriptstyle t math . Existence theory for differential inclusions with non convex F t , ... by Minty and Ha m Brezis . Applications Differential inclusions can be used to understand and suitably interpret discontinuous ordinary differential equations, such as arise for Coulomb friction ... of regularization was used by Nikolai Nikolaevich Krasovsky Krasovskii in the theory of differential game s. References Jean Pierre Aubin, Arrigo Cellina Differential Inclusions, Set Valued Maps And Viability .... Frankowska Set Valued Analysis , Birkh auser, Basel, 1990 Klaus Deimling Multivalued Differential ... more details
Refimprove date December 2008 File Differential linearity.svg thumb right Demonstrates A. Differential Linearity where a change in the input produces a corresponding change in output and B. Differential Non linearity, where the relationship is not directly linear Differential nonlinearity acronym DNL is a term describing the deviation between two analog values corresponding to adjacent input digital values. It is an important specification for measuring error in a digital to analog converter DAC the accuracy of a DAC is mainly determined by this specification. Ideally, any two adjacent digital codes correspond to output analog voltages that are exactly one Least significant bit Least Significant Bit LSB apart. Differential non linearity is a measure of the worst case deviation from the ideal 1 LSB step. For example, a DAC with a 1.5 LSB output change for a 1 LSB digital code change exhibits 1 2 LSB differential non linearity. Differential non linearity may be expressed in fractional bits or as a percentage of full scale. A differential non linearity greater than 1 LSB may lead to a non monotonic transfer function in a DAC. ref INL and DNL definitions A DNL error specification of less than or equal to 1LSB guarantees a monotonic transfer function with no missing codes. http www.maxim ic.com app notes index.mvp id 283 ref It is also known as a missing code . Differential linearity refers to a constant relation between the change in the output and input. For transducer s if a change in the input produces a uniform step change in the output the tranducer possess differential linearity. Differential linearity is desirable and is inherent to a system such as a single slope analog to digital convertor used in Particle detector nuclear instrumentation . Formula DNL Max V sub out sub i 1 V sub out sub i V sub ideal LSB step sub See also Integral nonlinearity References reflist External links http www.maxim ic.com appnotes.cfm an pk 283 INL DNL Measurements for High Speed Analog ... more details
about analogue differential analysers the digital implementation Digital Differential Analyzer Image ... The differential analyser is a mechanical analog computer analogue computer designed to solve differential .... ref cite web last Irwin first William url http amg.nzfmm.co.nz differential analyser explained.html title The Differential Analyser Explained work accessdate 2010 07 21 publisher http amg.nzfmm.co.nz ... thumb Kay McNulty , Alyse Snyder, and Sis Stump operate the differential ... , Philadelphia, Pennsylvania , c. 1942 1945. Image NASA Differential Analyzer.jpg thumb A differential ... Flight Propulsion Laboratory , 1951 Research on solutions for differential equations using mechanical ... Gustave Coriolis designed a mechanical device to integrate differential equations of the first ... could integrate differential equations of any order was published in 1876 by James Thomson engineer ..., William Thomson, 1st Baron Kelvin Lord Kelvin , which represents the invention of the differential analyser. ref Cite journal last Hartree first D.R. author link Douglas Hartree title The Bush Differential ... Mechanical Integration of Linear Differential Equations of the Second Order with Variable Coefficients ... Linear Differential Equation of any Order with Variable Coefficients journal Proceedings of the Royal ... mathematician Ernesto Pascal also developed integraph s for the mechanical integration of differential ... . ref However, the first widely practical differential analyser was constructed by Harold Locke ... last Robinson first Tim title The Meccano Set Computers A history of differential analyzers made from ... June doi 10.1109 MCS.2005.1432602 . Hartree, D.R. September 1940 , op. cit. ref ref Bush s differential ..., he called it a differential analyzer . ref Cite journal last Bush first V. title The differential analyzer. A new machine for solving differential equations journal Journal of the Franklin Institute ... the first differential analyzer was operational. ref Robinson, Tim June 2005 , op. cit. , citing Cite ... more details
during maturation Differential Signaling Hypothesis Differential signaling is a method of transmitting ... thumb upright 1.3 right Elimination of noise by using differential signaling. Advantages Tolerance of ground offsets Image Differential Signaling.png thumb 500px right In a system with a differential ... immunity . Differential signaling helps to reduce these problems because, for a given supply ... V V S math . Now consider a differential system with the same supply voltage. The voltage difference ... twice as much noise to cause an error with the differential system as with the single ended system ... is not actually due to differential signaling itself, but to the common practice of transmitting differential signals on balanced line s. ref cite web url http www.soundcraft.com support white ... would fail completely, the matching of the differential audio signals being irrelevant, though ... rejection property is independent of the presence of a desired differential signal. page 111 ... by a differential amplifier. See Balanced line for more details. Comparison with single ended signaling ... to operate at high speed. Examples Examples of differential signaling include LVDS , differential ... a common Ground electricity ground . Differential signaling is used with a balanced pair of conductors ... to behave as transmission line s. Use in computers Differential signaling is often used in computers ... into a small space, as on a typical PCB. High voltage differential signaling High voltage differential ... means 5 volts or more. SCSI 1 variations included a high voltage differential HVD implementation whose ... than the older HVD SCSI. The term high voltage differential signaling is a generic one that describes a variety of systems. Low voltage differential signaling or LVDS , on the other hand, is a specific system defined by a TIA EIA standard. See also Current mode logic CML Low voltage differential ... Transition Minimized Differential Signaling TMDS Longitudinal voltage Differential amplifier Differential ... more details
The main purpose of the electronic differential is to replace the Differential mechanical device mechanical differential in multi drive systems, providing the required torque for each driving wheel and allowing different wheel speeds. When cornering, the inner and outer wheels rotate at different speeds, because the inner wheels describe a smaller turning radius. The electronic differential uses the steering wheel command signal and the motor speed signals to control the power to each wheel so that all wheels have the maximum torque they need. Functional description The classical automobile drive train is composed by a single Internal combustion engine motor providing torque to one or more driving wheels. The most common solution is to use a mechanical device to distribute torque to the wheels. This Differential mechanical device mechanical differential allows different wheel speeds when cornering. With the emergence of electric vehicle s new drive train configurations are possible. Multi drive systems become easy to implement due to the large power density of electric motor s. These systems, usually with one motor per driving wheel, need an additional top level controller which performs the same task as a mechanical differential. The ED scheme has several advantages over a mechanical differential ref cite web url http ieeexplore.ieee.org search srchabstract.jsp?arnumber 1339466&isnumber 29535&punumber 41&k2dockey 1339466 ieeejrns&query 28 uot 3Cin 3Emetadata 29&pos 1 title Future vehicle driven by electricity and Control research ref simplicity it avoids additional mechanical parts such as a gearbox or clutch independent torque for each wheel allows additional capabilities e.g., traction control system traction control , stability control reconfigurable it is reprogrammable ... differential. faster response times accurate knowledge of traction torque per wheel. Applications ... and reducing tire wear. The Eliica is also equipped with electronic differential this eight wheeled ... more details
Unreferenced date December 2009 Differential rotation is seen when different parts of a rotating object ... s usually show differential rotation and examples in our solar system include the Sun , Jupiter and Saturn ... at the poles and at the equator, in good agreement with modern values. The cause of differential rotation ... is induced. Differential rotation is caused by convection in stars. This is movement of mass, due ... angular velocity in stellar wind s. Differential rotation thus depends on temperature differences in adjacent regions. Measuring differential rotation There are many ways to measure and calculate differential rotation in stars to see if different latitudes have different angular velocities. The most ... measurements of solar p modes it is possible to deduce the differential rotation. The Sun has very ... also plot 2. Solar differential rotation is also seen in magnetograms, images showing the strength and location of solar magnetic fields. Effects of differential rotation Gradients in angular rotation ... differential rotation is one part of the mixing processes in stars, mixing the materials and the heat energy of the stars. Differential rotation affects stellar optical absorption line spectra through ... surface. Solar differential rotation causes shear at the so called tachocline. This is a region where rotation changes from differential in the convection zone to nearly solid body rotation in the interior, at 0.71 solar radii from the center. Calculating differential rotation For observed sunspots, the differential rotation can be calculated as math Omega Omega 0 Delta Omega sin 2 Psi math ... for the equator to do a full lap more than the poles. The relative differential rotation rate is the ratio ... measured from the poles . Differential rotation of the Sun File Tachocline.gif thumb right 200px Internal rotation in the Sun, showing differential rotation in the outer convective region and almost ... speed of 2 km s its differential rotation implies that the angular velocity decreases with increased ... more details
one source date December 2010 File Differential sticking.svg thumb 250px right A diagram showing forces at work during differential sticking. The small black arrows represent pressure exerted on the drill pipe from the wellbore, the red arrows represent pressure exerted on the pipe from the formation smaller than in the wellbore and the large black arrow represents the net force on the pipe, which is pushing it into the wall. Differential sticking is a problem that occurs when drilling a Oil well well with a greater well bore pressure than formation pressure, as is usually the case. The drill pipe is pressed against the wellbore wall so that part of its circumference will see only reservoir pressure, while the rest will continue to be pushed by wellbore pressure. As a result the pipe becomes stuck to the wall, and can require millions of pounds of force to remove, which may prove impossible. In many cases the drilling fluid mud weight is simply reduced, thus relieving the pressure difference and releasing the stuck pipe string. Should this option be unavailable, as in sour gas wells, a specialty fishing company is called to retrieve the stuck pipe or fish . Many options exist once a fishing company is on site oil or nitrogen may be pumped down the well, or the fish may be washed over using a carbide shoe on a string of washpipe. Jarring is not usually attempted with differential sticking due to the massive amount of pressure that holds the pipe in place. External links http www.glossary.oilfield.slb.com Display.cfm?Term differential 20sticking Schlumberger Oilfield Glossary about differential sticking petroleum stub Category Drilling technology br Petroleum industry ... more details
Differential weathering is the difference in degree of discoloration , disintegration , of rocks of different kinds exposed to the same environment. Quartz deposits in basaltic flows will weather slower than the surrounding rock, while being exposed to the same forces of weathering. More simply, Differential weathering is the chemical or physical breakdown of different rock units at different rates. The rate of breakdown is determined by several factors the rocks mineral composition, surface area, climate, time, etc. Landforms created by differential weathering consist of balanced rocks, cliff and bench topography, natural arches, natural bridges, and fins. References Reynolds, Stephen, Julia Johnson, Paul Morin, and Charles Carter. Exploring Geology. 2nd. 1. New York City McGraw Hill, 2010. Print. Northern Kentucky University Geology Dept. reflist Category Geomorphology climate stub ja ... more details
Image Op amp symbol.svg frame right div style text align center Differential amplifier symbol div The inverting ... the diagram for simplicity, but of course must be present in the actual circuit. A differential amplifier ... not amplify the particular voltages. Theory Many electronic devices use differential amplifiers internally. The output of an ideal differential amplifier is given by math V text out A text d V text ... A text d math is the differential gain. br In practice, however, the gain is not quite equal for the two ... of a differential amplifier thus includes a second term. math V text out A text d V text in V ... mode gain of the amplifier. br As differential amplifiers are often used to null out noise or bias ... ratio CMRR , usually defined as the ratio between differential mode gain and common mode gain ... In a perfectly symmetrical differential amplifier, math A text c math is zero and the CMRR is infinite. Note that a differential amplifier is a more general form of amplifier than one with a single input by grounding one input of a differential amplifier, a single ended amplifier results. Long tailed ... Invented the Differential Amplifier? . IEEE Engineering in Medicine and Biology, May June 1996 .... Configurations A differential long tailed, ref group nb Long tail is a figurative name of high resistance ... length at differential mode this tail shortens up to zero . If additional emitter resistors ... negative feedback at differential mode , they can be figuratively represented by short tails . ref ... degeneration emitter , Common source source or Valve amplifier cathode degeneration. Differential output ... and two outputs, this forms a differential amplifier stage Fig. 2 . The two bases or grids or gates ... with a differential balanced input signal, or one input could be grounded to form a phase splitter circuit. An amplifier with differential output can drive floating load or another stage with differential input. Single ended output If the differential output is not desired, then only one output can ... more details
Differential Inheritance is a common Inheritance object oriented programming inheritance model used by Prototype based programming prototype based programming languages such as JavaScript , Io programming language Io and NewtonScript . It operates on the principle that most objects are derived from other, more general objects, and only differ in a few small aspects while usually maintaining a list of pointers internally to other objects which the object differs from. An Analogy To think of differential inheritance, you think in terms of what is different. So for instance, when trying to describe to someone how Dumbo looks, you could tell them in terms of elephants Think of an elephant. Now Dumbo is a lot shorter, has big ears, no tusks, a little pink bow and can fly. Using this method, you don t need to go on and on about what makes up an elephant, you only need to describe the differences anything not explicitly different can be safely assumed to be the same. External links http developer.mozilla.org en docs Differential inheritance in JavaScript Differential inheritance in JavaScript Mozilla Developer Center article See also Inheritance object oriented programming Single inheritance Category Object oriented programming soft eng stub es Herencia diferencial ... more details
More footnotes date March 2009 Differential cryptanalysis is a general form of cryptanalysis applicable ... . History The discovery of differential cryptanalysis is generally attributed to Eli Biham and Adi ... and Shamir that DES is surprisingly resistant to differential cryptanalysis, in the sense that even ... stating that differential cryptanalysis was known to IBM as early as 1974, and that defending against differential cryptanalysis had been a design goal. ref name coppersmith cite journal doi 10.1147 ... ref According to author Steven Levy , IBM had discovered differential cryptanalysis on its own, and the NSA ... would reveal the technique of differential cryptanalysis, a powerful technique that could be used ... over other countries in the field of cryptography. ref name coppersmith Within IBM, differential ... to differential cryptanalysis in mind, other contemporary ciphers proved to be vulnerable ... round version of FEAL is susceptible to the attack. Attack mechanics Differential cryptanalysis is usually .... The resulting pair of differences is called a differential . Their statistical properties ... basic form of key recovery through differential cryptanalysis, an attacker requests the ciphertexts for a large number of plaintext pairs, then assumes that the differential holds for at least ... probable differences through the various stages of encryption, termed a differential characteristic . Since differential cryptanalysis became public knowledge, it has become a basic concern of cipher ... or known plaintext inputs suggests possible key values. For example, if a differential of 1 1 implying ... or 2 pairs of inputs is that differential possible. Suppose we have a non linear function where the key is XOR ed before evaluation and the values that allow the differential are 2,3 and 4,5 . If the attacker ... function one would ideally seek as close to 2 sup n 1 sup as possible to achieve differential uniformity . When this happens, the differential attack requires as much work to determine the key as simply ... more details
In mathematics , a differential operator is an Operator mathematics operator defined as a function of the derivative ..., which are the most common type. However, non linear differential operators, such as the Schwarzian derivative also exist. Notations The most common differential operator is the action of taking ... , who considered differential operators of the form math sum k 0 n c k D k math in his study of differential equation s. One of the most frequently seen differential operators is the Laplace operator ... Another differential operator is the operator, or theta operator, defined by ref cite web url http ... of applying the differential to the left Clarify date February 2012 and to the right Clarify date February 2012 , and the difference obtained when applying the differential operator to the left ... Main Del The differential operator del is an important Euclidean vector vector differential operator. It appears frequently in physics in places like the differential form of Maxwell s Equations . In three ... of an operator See also Hermitian adjoint Given a linear differential operator T math Tu sum k 0 n ... n sup , and P a differential operator on , then the adjoint of P is defined in Lp space L sup 2 ... example of a formal self adjoint operator. This second order linear differential operator L can be written ... of this operator are considered. Properties of differential operators Differentiation is linearity ..., and a is a constant. Any polynomial in D with function coefficients is also a differential operator. We may also compose differential operators by the rule math D 1 circ D 2 f D 1 D 2 f . , math ... another way it consists of the translation invariant operators. The differential operators also ... see symmetry of second derivatives . Coordinate independent description In differential geometry and algebraic geometry it is often convenient to have a coordinate independent description of differential ... to be a k th order linear differential operator if it factors through the jet bundle J sup k sup ... more details
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