Orphan date February 2009 In X ray crystallography , the Flack parameter is a factor used to estimate the absolute configuration of a structural model determined by single crystal structure analysis. In this approach, one determines the absolute structure of a noncentrosymmetric crystal. The processes used to decide the absolute structure use the anomalous dispersion effect . If atomic scattering factors did not have Complex number imaginary parts , the Friedel pair s would have exactly the same amplitude s i.e., the scattering intensity math F h k l 2 math from crystal plane h k l is equal to math F h k l 2 math . However, atomic scattering factors have imaginary part s due to the anomalous dispersion effect , and Friedel s law is broken by this effect. There are several ways to determine the absolute structure by X ray crystallography. For example, a comparison of the intensities of Bijvoet pairs or of the R factors for the two possible structures can suggest the correct absolute structure. One of the more powerful and simple approaches is using the Flack parameter, because this single parameter clearly indicates the absolute structure. The Flack parameter is calculated during the structural refinement using the equation given below math I hkl 1 x F h k l 2 x F h k l 2 math explain this formula where x is the Flack parameter, I is the square of the scaled observed structure factor and F is the calculated structure factor. By determining x for all data, x is usually found to be between 0 and 1. If the value is near 0, with a small standard uncertainty , the absolute structure given by the structure refinement is likely correct, and if the value is near 1, then the inverted structure is likely correct. If the value is near 0.5, the crystal may be racemic or twinned. The technique is most effective when the crystal contains both lighter and heavier atoms. Light atoms usually show only a small anomalous dispersion effect. This parameter, introduced by H. D. Flack ref cite ... more details
In the geometry of complex algebraic curve s, a local parameter for a curve C at a smooth point P is just a meromorphic function on C that has a simple zero at P . This concept can be generalized to curves defined over fields other than math mathbb C math or even scheme mathematics scheme s , because the local ring at a smooth point P of an algebraic curve C defined over an algebraically closed field is always a discrete valuation ring . ref J. H. Silverman 1986 . The arithmetic of elliptic curves . Springer. p. 21 ref This valuation will endow us with a way to count the order at the point P of rational functions which are natural generalizations for meromorphic functions in the non complex realm having a zero or a pole at P . Local parameters, as its name indicates, are used mainly to properly count multiplicities in a local way. Introduction When C is a complex algebraic curve, we know how to count multiplicities of zeroes and poles of meromorphic functions defined on it ref R. Miranda 1995 . Algebraic curves and Riemann surfaces . American Mathematical Society. p. 26 ref . However, when discussing curves defined over fields other than math mathbb C math , we do not have access to the power of the complex analysis, and a replacement must be found in order to define multiplicities of zeroes and poles of rational functions defined on such curves. In this last case, we say that the germ of the regular function math f math vanishes at math P in C math if math f in m P subset mathcal O C,P math . This is in complete analogy with the complex case, in which the maximal ideal of the local ... with the concept of a Discrete valuation ring Uniformizing parameter uniformizing parameter ... parameter for the DVR R, m is just a generator of the maximal ideal m . The link comes from the fact that a local parameter at P will be a uniformizing parameter for the DVR math mathcal O C ... on the local ring math mathcal O C,P math , math m P math . A local parameter for C at P is a function ... more details
. When both source distributions are central either with a zero mean or a zero noncentrality parameter ... distributions that are not usually formulated in terms of a noncentrality parameter see noncentral hypergeometric distributions , for example. The noncentrality parameter of the t distribution may ... more details
Orphan date October 2008 The Binder parameter ref K. Binder, Z. Phys. B 43, 119 1981 ref in statistical physics , also known as the fourth order culumant math U L 1 frac langle s 4 rangle L 3 langle s 2 rangle 2 L math in Ising model ref K. Binder & D. W. Heermann, Monte Carlo Simulation in Statistical Physics An Introduction, Ed. 4, Spring ref , is used to identify phase transition points in numerical simulations. It is defined as the kurtosis of the order parameter. For example in spin glass es one defines the Binder as math B frac 1 2 left 3 frac overline langle q 4 rangle overline langle q 2 rangle 2 right math where math langle cdot rangle math stands for Boltzmann average, math overline cdot math for average over the disorder and math q math is the overlap between two identical replicas of the system. The phase transition point is usually identified comparing the behavior of math B math as a function of the temperature for different values of the system size math L math . The transition temperature is the unique point where the different curves cross. This is based on finite size scaling hypothesis, according to which, in the critical region math T approx T c math the Binder behaves as math B T,L b epsilon L 1 nu math , where math epsilon frac T T c T math . References references Category Statistical mechanics condensedmatter stub ... more details
Orphan date July 2011 In statistics as applied in particular in particle physics , when fluctuation s of some observable s are measured, it is convenient to transform the multiplicity distribution to the bunching parameters math eta q frac q q 1 frac P q P q 2 P q 1 2 , math where math P n math is probability of observing math n math objects inside of some phase space regions. The bunching parameters measure deviations of the multiplicity distribution math P n math from a Poisson distribution , since for this distribution math eta q 1 math . Uncorrelated particle production leads to the Poisson distribution Poisson statistics , thus deviations of the bunching parameters from the Poisson values mean correlations between particles and dynamical fluctuations. Normalised factorial moment s have also similar properties. They are defined as math F q langle n rangle q sum infty n q frac n n q P n. math References reflist cite journal last Chekanov first S.V. last2 Kuvshinov first2 V.I. year 1994 title Bunching Parameter and Intermittency in High Energy Collisions url http th www.if.uj.edu.pl acta vol25 pdf v25p1189.pdf journal Acta Physica Polonica B volume 25 issue pages 1189 1197 doi arxiv hep ph 9605379 bibcode 1996hep.ph....5379C cite journal last Chekanov first S.V. last2 Kittel first2 W. last3 Kuvshinov first3 V.I. year 1996 title Multifractal Multiplicity Distribution in Bunching Parameter Analysis journal Journal of Physics G volume 22 issue 5 pages 601 610 doi 10.1088 0954 3899 22 5 007 arxiv hep ph 9606202 bibcode 1996JPhG...22..601C cite journal last Chekanov first S.V. last2 Kuvshinov first2 V.I. year 1997 title Generalized Bunching Parameters and Multiplicity Fluctuations in Restricted Phase Space Bins journal Zeitschrift f r Physik C volume 74 issue 3 pages 517 529 doi 10.1007 s002880050414 arxiv hep ph 9606335 last3 Kuvshinov first3 V. I. DEFAULTSORT Bunching Parameter Category Particle physics Category Statistical mechanics physics stub eo Beraranta paramet ... more details
The Fried parameter ref cite journal last Fried first D. L. title Optical Resolution Through a Randomly Inhomogeneous Medium for Very Long and Very Short Exposures journal Journal of the Optical Society of America year 1966 month October volume 56 issue 10 pages 1372 1379 doi 10.1364 JOSA.56.001372 url http www.opticsinfobase.org abstract.cfm?id 53167 bibcode 1966JOSA...56.1372F ref or Fried s coherence length commonly written as math r 0 math measures the optical quality of the atmosphere . This parameter is usually expressed in centimeters and corresponds to an area over which the rms wavefront aberration is less than 1 radian . As such, math r 0 math indicates the size of a telescope which can just operate at the diffraction limit . Any larger and resolution will be seeing limited, any smaller and it will be limited by the telescope itself. Although not explicitly written in his article, Fried s parameter is usually written as math r 0 left 0.423 , k 2 , sec zeta int mathrm Path C n 2 z , dz right 3 5 . math ref cite book last Hardy first Johw W. title Adaptive optics for astronomical telescopes year 1998 publisher Oxford University Press pages 428 url http openlibrary.org works OL2633873W Adaptive optics for astronomical telescopes page 92 isbn 0195090195 ref where math C N 2 z math is the structure constant for the index of refraction, measuring the strength of turbulence versus altitude, math k 2 pi lambda math is the angular Wavenumber , and math zeta math is the angle of the telescope, measured from zenith. Typical values for math r 0 math are 10 cm for average seeing and 20 cm for good to excellent seeing on the best sites. The seeing limited angular resolution is math lambda r 0 math . Since almost all professional telescopes have diameter math D math larger than math r 0 math , they employ adaptive optics to correct the aberrations and get diffraction limited images, with resolution of math lambda D math . Because math r 0 math varies with wavelength as math ... more details
Unreferenced date December 2009 In computing , a procedural parameter is a parameter computer science parameter of a subroutine procedure that is itself a procedure. This concept is an extremely powerful and versatile programming tool, because it allows programmers to modify certain steps of a library computer science library procedure in arbitrarily complicated ways, without having to understand or modify the code of that procedure. This tool is particularly effective and convenient in languages that support nested function local function definitions , such as Pascal programming language Pascal and the modern GNU Compiler Collection GNU dialect of C programming language C . It is even more so when closure computer science function closures are available. The same functionality and more is provided by object computing object s in object oriented programming object oriented programming language s, but at a significantly higher cost. Basic concept In most languages that provide this feature, a procedural parameter f of a subroutine P can be called inside the body of P as if it were an ordinary ... argument, that must be some previously defined function compatible with the way P uses its parameter ... type declaration for each procedural parameter f , including the number and type of its arguments ... parameter f . This usually means that actf and f must return the same type of result, must ... is passed as argument to P , as its procedural parameter f and f is then called from inside the body ... . Example Generic insertion sort The concept of procedural parameter is best explained by examples ... a third parameter incr is true or false , respectively procedure vecsort n , v , incr procedure ... of nested function definitions to get a function vprec whose effect depends on the parameter incr ... parameter passing mechanism that could simplify some uses of procedural parameters see Jensen ... Procedural Parameter Category Subroutines ... more details
The Shields parameter , also called the Shields criterion or Shields number , is a nondimensional number used to calculate the initiation of motion of sediment in a fluid flow . It is a nondimensionalization of a shear stress , and is typically denoted math tau ast math or math theta math . It is given by math tau ast theta frac tau rho s rho g D , math where style border 0px math tau math is a dimensional shear stress math rho s math pad 1em is the density of the sediment math rho math is the density of the fluid math g math is acceleration due to gravity math D math is a characteristic particle diameter of the sediment. Physical meaning By multiplying the top and bottom of the Shields parameter by D sup 2 sup , you can see that it is proportional to the ratio of fluid force on the particle to the weight of the particle. References cite book first A. last Shields title Anwendung der Aehnlichkeitsmechanik und der Turbulenzforschung auf die Geschiebebewegung language German trans title Application of similarity mechanics and turbulence research on shear flow publisher Preu ischen Versuchsanstalt f r Wasserbau location Berlin series Mitteilungen der Preu ischen Versuchsanstalt f r Wasserbau volume 26 year 1936 url http repository.tudelft.nl assets uuid 61a19716 a994 4942 9906 f680eb9952d6 Shields.pdf cite book first A. last Shields title Anwendung der Aehnlichkeitsmechanik und der Turbulenzforschung auf die Geschiebebewegung language English trans title Application of similarity principles and turbulence research to bed load movement publisher Preu ischen Versuchsanstalt f r Wasserbau location Berlin series Mitteilungen der Preu ischen Versuchsanstalt f r Wasserbau volume 26 year 1936 url http repository.tudelft.nl assets uuid a66ea380 ffa3 449b b59f 38a35b2c6658 Shields Application of Similarity Principles and Turbulence Research to Bed Load Movement.pdf External links cite web url http ocw.mit.edu courses earth atmospheric and planetary sciences 12 090 special topics ... more details
When an atom has more than one electron there will be some electrostatic repulsion between those electrons. The amount of repulsion varies from atom to atom, depending upon the number and spin physics spin of the electrons and the atomic orbital orbital s they occupy. The total repulsion can be expressed in terms of three parameters A , B and C which are known as the Racah parameters after Giulio Racah , who first described them. They are generally obtained empirically from gas phase spectroscopic studies of atoms. ref cite book last Ballhausen first C.J. title Molecular Electronic Structure of Transition Metal Complexes year 1980 publisher McGraw Hill isbn 10 0070034958 ref They are often used in transition metal chemistry to describe the repulsion energy associated with an electronic term symbol term . For example, the interelectronic repulsion of a sup 3 sup P term is A 7 B , and of a sup 3 sup F term is A 8 B , and the difference between them is therefore 15 B . See also Tanabe Sugano diagram Nephelauxetic effect References reflist cite journal author Junge L, Parlitz U title Phase synchronization of coupled ginzburg landau equations journal Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics volume 62 issue 1 Pt A pages 438 41 year 2000 month July pmid 11088478 doi url physical chemistry stub Category Coordination chemistry Category Spectroscopy de Racah Parameter pl Parametr Racah ... more details
In mathematics , a one parameter group or one parameter subgroup usually means a continuous topology continuous group homomorphism R G from the real line R as an additive group to some other topological group G . That means that it is not in fact a group mathematics group , strictly speaking if is injective then R , the image, will be a subgroup of G that is isomorphic to R as additive group. Discussion That is, we start knowing only that s t s t where s , t are the parameters of group elements in G . We may have s e , the identity element in G , for some s 0. This happens for example if G is the Circle group unit circle and s e sup is sup . In that case the kernel algebra kernel of consists of the integer multiples of 2 . The action group theory action of a one parameter group on a set is known as a flow mathematics flow . A technical complication is that R as subspace of G may carry a topology that is finer topology coarser than that on R this may happen in cases where ... a straight line round T at an irrational slope. Therefore a one parameter group or one parameter ... not be the standard one of the real line. Examples Such one parameter groups are of basic importance ... s on a Hilbert space . See Stone s theorem on one parameter unitary groups . In his 1957 monograph ... Lie group is locally isomorphic to R . Physics In physics , one parameter groups describe dynamical ... Verlag, 1995. ref Furthermore, whenever a system of physical laws admits a one parameter group ... , the theory of special relativity provided a calculus of relative motion with the one parameter group ... theory. Since rapidity is unbounded, the one parameter group it stands upon is non compact. The rapidity concept was introduced by E.T. Whittaker in 1910, and named by Alfred Robb the next year. The rapidity parameter amounts to the length of a versor Hyperbolic versor hyperbolic versor , a concept ... and r sup 2 sup 1. See also Integral curve One parameter semigroup Noether s theorem ... more details
The following program in the C programming language C programming language defines a function that is named sales tax and has one parameternamed price . The type of price is double i.e. a floating ... 1955 Named parameters Some programming languages allow subroutines to have namedparameter s. This allows ...In computer programming , a parameter is a special kind of Variable programming variable , used in a subroutine ... value passed to a function, procedure, or routine such as 37 in log 37 , whereas the parameter is a reference to that value inside the implementation of the function log in this case . See the Parameter ... information. In the most common case, call by value , a parameter acts within the subroutine as a Local ..., argument is sometimes used in place of parameter . Nevertheless, there is a difference. Properly, parameters appear in procedure definitions arguments appear in procedure calls. A parameter ... that specifies the parameters is called its parameter list . By contrast, the arguments are the values ... properly thought of as the actual values or references assigned to the parameter variables when ..., and the place in the code where these values or references are given is the parameter list . When discussing the code inside the subroutine definition, the variables in the subroutine s parameter list ... type source lang c void ThreadFunction void pThreadArgument Naming the first parameter pThreadArgument ... above, reserve the term parameter when discussing subroutine definitions. source Many programmers use parameter and argument interchangeably, depending on context to distinguish the meaning. The term formal parameter refers to the variable as found in the function definition parameter , while actual parameter refers to the actual value passed argument . To better understand the difference ..., int addend2 return addend1 addend2 source The function sum has two parameters, named addend1 and addend2 ... a mismatch between the parameter and argument lists, and the procedure will often return an unintended ... more details
Who Named It? is an English language dictionary of medical eponyms and the people associated with their identification. Though this is a dictionary, many eponyms and persons are presented in extensive articles with comprehensive bibliographies. It is hosted in Norway and maintained by medical historian Ole Daniel Enersen . External links http www.whonamedit.com Official website http www.quantcast.com whonamedit.com Demographic and traffic data on Who Named It? at Quantcast http jnnp.bmj.com cgi content full 74 12 1614 Journal of Neurology, Neurosurgery, and Psychiatry Who named it? Category Medical websites Category Medical dictionaries Ref book stub Website stub cs Who Named It? es Who Named It? fr Who Named It? it Who Named It? no WhoNamedIt.com pt Who Named It? sr Who Named It ... more details
In computing , a named pipe also known as a FIFO for its behavior is an extension to the traditional ... as the process is running. A named pipe is system persistent and exists beyond the life of the process and must be deleted once it is no longer being used. Processes generally attach to the named pipes ..., unnamed, shell pipeline, a named pipeline makes use of the filesystem. It is explicitly created ... my pipe The named pipe can be deleted just like any file rm my pipe A named pipe can be used to transfer .... For example you can pipe the output of gzip into a named pipe like so mkfifo mode 0666 tmp namedPipe ... DATA INFILE Syntax ref like so LOAD DATA INFILE tmp namedPipe INTO TABLE tableName Without this named ... loading data from named pipes. ref http postgresql.1045698.n5.nabble.com psql and named pipes td1981226.html ref In Windows In Windows, the design of named pipes is based towards client server communication .... Windows named pipes also support an explicit passive mode for server applications compare Unix domain socket s . Windows 95 supports named pipe clients. The Windows NT family of operating systems support named pipe clients and servers. A named pipe can be accessed much like a file. Win32 SDK ..., respectively. There is no command line interface like in Unix. Named pipes cannot be mounted within a normal filesystem, unlike in Unix. Also unlike their Unix counterparts, named pipes are volatile removed after the last reference to them is closed . Every pipe is placed in the root directory of the named pipe filesystem NPFS , mounted under the special path . pipe that is, a pipe named foo would have a full path name of . pipe foo . Anonymous pipes used in pipelining are actually named pipes ... expose emulated serial port s to the host system as named pipes, and the WinDbg kernel mode debugger from Microsoft supports named pipes as a transport for debugging sessions in fact, VMware and WinDbg ... computer . Both programs require the user to enter names in the . pipe name form. Windows NT Named ... more details
File Named graphs 1.jpg thumb 300px A Named Graph Named graphs are a key concept of Semantic Web architecture in which a set of Resource Description Framework statements a Graph mathematics graph are identified using a URI , ref strictly speaking a URIRef ref allowing descriptions to be made of that set of statements such as context, provenance information or other such metadata . Named graphs are a simple .... Named graphs and HTTP One conceptualization of the Web is as a graph of document nodes identified ... Graph . ref http dig.csail.mit.edu breadcrumbs node 215 Giant Global Graph ref File Named graphs 2.jpg thumb 300px Describing a Named Graph Named graphs are a formalization of the intuitive idea that the contents of an RDF document a graph on the Web can be considered to be named by the URI of the document ... the publisher applying a digital signature to the data in the named graph. Support for these facilities ... ref http www.w3.org DesignIssues Reify.html Reification of RDF and N3 ref . Named graphs and RDF stores While named graphs may appear on the Web as simple linked documents i.e. Linked Data , they are also ... query may be limited to a specific set of named graphs. Example Assume the following Turtle ... NAMED http example.org joe WHERE GRAPH ?g ?person foaf homepage ?homepage . ?person foaf mbox mailto joe example.org . source The FROM NAMED here identifies the target graph for the query. Named graphs and quads Prior to the publication of the papers describing named graphs, there was considerable ... of context subject predicate object . Named graphs can be represented this way, as graphname ... 1 http www2005.org cdrom docs p613.pdf Named Graphs, Provenance and Trust ref Specifications There is currently no specification for named graphs in themselves beyond that described in ref name Carroll ... in XML ref which includes syntaxes for representing named graphs , however they do form part of the SPARQL ... publisher Jeni Tennison accessdate 6 July 2011 References references DEFAULTSORT Named Graph Category ... more details
Infobox book series name The Books of the Named image include the file, px and alt File Example.jpg 200px Cover image caption books Ratha s Creature br Clan Ground br Ratha and Thistle chaser br Ratha s Challenge br Ratha s Courage author Clare Bell cover artist country language genre Prehistoric fiction , Speculative fiction , Adventure publisher pub date 1983 2008 media type number of books 5 The Books of the Named also known as the Ratha series is a series of young adult fiction young adult prehistoric fiction novels by Clare Bell . External links http rathascourage.com Ratha s Courage , author and fan website for the series http wiki.wandsandworlds.com Ratha and the Named Ratha and the Named , Wands and Worlds community wiki http www.freewebs.com trailsofconquest Trails of Conquest , fan website Uncategorized date April 2012 ya novel stub ... more details
distinguish Name and Shame Infobox Album See Wikipedia WikiProject Albums Name Named and Shamed Type Studio album Artist The Flaming Stars Cover Named and Shamed.jpg Released 16 November 2004 Recorded 16 April 2004 18 May 2004 Genre Garage Punk , Indie rock Length Label UK Vinyl Japan br US Alternative Tentacles Producer The Flaming Stars Reviews Allmusic Rating 4 5 Allmusic class album id r713526 pure url yes link Named and Shamed is the sixth studio album by The Flaming Stars . It was recorded and mixed by Ed Deegan at Toe Rag Studios . Track listings She s Gone 2 40 Where the Beautiful People Go 2 03 The Marabou Shuffle 3 27 Spilled Your Pint 3 24 Another Dial 2 54 The Parade s Gone By 3 37 Stranger on the Fifth Floor 4 34 If You Give Em a Chance 2 04 Bess of the Boneyard 2 45 The 39 Stops 2 30 Nine Out of Ten 2 11 Named & Shamed 3 12 Locked in Tight 2 38 DEFAULTSORT Named And Shamed Category 2004 albums Category The Flaming Stars albums 2000s indie rock album stub ... more details
In linguistics , the subject side parameter , sometimes referred to as the specifier head parameter , is a proposed Principles and parameters parameter that provides a choice between Subject grammar Subject s come before head linguistics head s subject first and Subjects come after heads subject last . English language English is an example of a subject first language, whereas Malagasy language Malagasy is an example of subject last . See also Principles and parameters References Mark Baker linguist Baker, M . 2001 The Atoms of Language ling stub Category Generative linguistics ... more details
The Zener Hollomon parameter is used to help describe high temperature creep strain of a material such as steel. ref Fire Safety Engineering, J.A. Purkiss, 2007, 2nd ed. Butterworth Heinemann. Oxford ref See also Hollomon Jaffe parameter References reflist Category Metallurgy ... more details
multiple issues original research November 2011 orphan November 2011 unreferenced November 2011 In linguistics , the ergative case parameter is a proposed Principles and parameters parameter that classifies a language as Ergative absolutive language ergative absolutive or Nominative accusative language nominative accusative accordingly to how nouns are declined as subjects or objects of a sentence. Category Linguistics ... more details
Infobox cycling team teamname Utensilnord Named image Deleted image removed File logoderosa.JPG 150px code UNA base IRL founded start date 2010 disbanded manager Giovanni Fidanza teammanager techdirector discipline Road status UCI Professional Continental Professional Continental season 2010 br 2011 br 2012 oldname De Rosa Stac Plastic br De Rosa Ceramica Flaminia br Utensilnord Named kitimage current Utensilnord Named UCI code UNA is a UCI Professional Continental cycling team, registered in Ireland . The team participates in UCI Continental Circuits races. The team was founded in 2010 as De Rosa Stac Plastic after the disappearance of ct LPR 2009 . Major results 2010 1st Overall Giro della Provincia di Reggio Calabria , Matteo Montaguti 1st Stage 1, Matteo Montaguti 1st GP di Lugano , Roberto Ferrari cyclist Roberto Ferrari 1st Giro del Friuli , Roberto Ferrari cyclist Roberto Ferrari 1st Overall Tour of Japan , Cristiano Salerno 1st Stage 2 & 5, Cristiano Salerno 1st Stage 3 & 7, Claudio Cucinotta 1st Stage 5 Brixia Tour , Roberto Ferrari cyclist Roberto Ferrari 1st Trofeo Matteotti , Riccardo Chiarini Team As of 14 February 2012. ref cite web url http 62.50.72.82 ucinet default.asp?page UCITeamsdetail&discipline ROA&continent ALL&teamscategory &teamstype PCT&year 2012&teamnameid 3361&npage &search &l ENG title Utensilnord Named UNA IRL accessdate 14 February 2012 work UCI Continental Circuits publisher Union Cycliste Internationale ref Cycling squad start Cycling squad rider name John Lee Augustyn nat RSA birthdate birth date and age df yes 1986 08 10 Cycling squad rider name Filippo Baggio nat ITA birthdate birth date and age df yes 1988 06 05 Cycling squad rider name Paolo Bailetti nat ITA birthdate birth date and age df yes 1980 07 15 Cycling squad rider name Oleg ... stub cycling team stub de Utensilnord Named es Utensilnord Named fr quipe cycliste Utensilnord Named it Utensilnord Named hu Utensilnord Named nl Utensilnord Named ... more details
Orphan date November 2009 refimprove date November 2010 The Hollomon Jaffe parameter , or HP , describes the effect of a heat treatment at a temperature for a certain time. ref Name Brooks cite book title Principles of the heat treatment of plain carbon and low alloy steels last Brooks first Charlie authorlink Charlie R. Brooks year 1996 publisher ASM International isbn 0871705389 page 158 url http books.google.com books?id fVIlbCFTodgC&pg PA158&dq 22Hollomon Jaffe parameter 22&hl en&ei MM STNDEGsOblgeJ4M3vDQ&sa X&oi book result&ct result&resnum 2&ved 0CCwQ6AEwAQ v onepage&q 22Hollomon Jaffe 20parameter 22&f false ref Effect The effect of the heat treatment depends on its temperature and its time . The same effect can be achieved with a low temperature and a long holding time, or with a higher temperature and a short holding time. Formula In the Hollomon Jaffe parameter, This exchangeability of time and temperature can be described by the following formula math H p frac 273.15 T 1000 cdot C log t math This formula is not consistent concerning the units the parameters must be entered in a certain manner. T is in degrees Celsius. The argument of the Logarithm logarithmic function has the unit hour s. C is a parameter unique to the material used. The Hollomon parameter itself is Dimensionless quantity unitless and realistic numeric values vary between 15 and 21. math H p T C log t , math where T is in kilokelvin s, t is in hours, and C is the same as above. References reflist See also Zener Hollomon parameter DEFAULTSORT Hollomon Jaffe Parameter Category Metal heat treatments de Hollomon Jaffe Parameter ... more details
Orphan date December 2009 In optics , the complex beam parameter is a complex number that specifies the properties of a Gaussian beam at a particular point z along the axis of the beam. It is usually denoted by q . It can be calculated from the beam s vacuum wavelength sub 0 sub , the radius of curvature R of the phase front , the index of refraction n n 1 for air , and the beam radius w defined at 1 e sup 2 sup intensity , according to ref name Yariv cite book first Amnon last Yariv year 1989 title Quantum Electronics edition 3rd publisher Wiley isbn 0 4716 0997 8 ref math frac 1 q z frac 1 R z frac i lambda 0 pi n w z 2 math . Alternatively, q can be calculated according to math q z z z 0 i , math ref name Yariv where z is the location at which q is calculated, relative to the location of the beam waist , z sub 0 sub is the Rayleigh range , and i is the imaginary unit . Uses of the complex beam parameter The complex beam parameter is usually used in ray transfer matrix analysis , which allows the calculation of the beam properties at any given point as it propagates through an optical system, if the ray matrix and the initial complex beam parameter is known. This same method can also be used to find the fundamental mode size of a stable optical resonator . Given the initial beam parameter, q sub i sub , one can use the ray transfer matrix of an optical system, math begin pmatrix A & B C & D end pmatrix math , to find the resulting beam parameter, q sub f sub , after the beam has traversed the system ref name Yariv math q f frac Aq i B Cq i D math . It is often convenient ... i A B q i math . To find the complex beam parameter of a stable optical resonator , one needs to find ... , a quadratic is formed as math C q f 2 D A q f B 0 math . Solving this equation gives the beam parameter for the chosen starting position in the cavity, and by propagating, the beam parameter for any other location in the cavity can be found. References references DEFAULTSORT Complex Beam Parameter ... more details
Orphan date February 2009 Duplication The Larson Miller parameter is a means of predicting the lifetime of material vs. time and temperature using a correlative approach based on the Arrhenius rate equation. The value of the parameter is usually expressed as LMP T C log t where C is a material specific constant often approximated as 20, t is the time in hours and T is the temperature in Kelvin. Creep deformation Creep stress rupture data for high temperature creep resistant alloys are often plotted as log stress to rupture versus a combination of log time to rupture and temperature. One of the most common time temperature parameters used to present this kind of data is the Larson Miller L.M. parameter, which in generalized form is math P L.M. T log t r C math T temperature, K or R br math t r math stress rupture time, h br C constant usually of order 20 According to the L.M. parameter, at a given stress level the log time to stress rupture plus a constant of the order of 20 multiplied by the temperature in kelvins or degrees Rankine remains constant for a given material. References G. E. Fuchs, High Temperature Alloys, Kirk Othmer Encyclopedia of Chemical Technology Smith & Hashemi, Foundations of Material Science and Engineering See also Larson Miller relation Creep deformation Category Materials science ... more details
In telecommunication , a password length parameter is a basic parameter the value of which affects password strength against brute force attack and so is a contributor to computer security . One use of the password length parameters is in the expression math P L times R S math , where math P math is the probability that a password can be guessed in its lifetime, math L math is the maximum lifetime a password can be used to log in to a system , math R math is the number of guesses per unit of time , and math S math is the number of unique algorithm generated passwords the password space . The degree of password security is determined by the probability that a password can be guessed in its lifetime. References FS1037C Category Computer network security Category Password authentication ... more details
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