book based novel work oxidation reduction experiments ref name laidler ref first chemical reaction organic chemistry utilized catalyst studied gottlieb kirchhoff discovered acid catalyzed conversion starch glucose term ''catalysis'' later used j ns jakob berzelius describe reactions accelerated substances remain unchanged reaction fulhame predated berzelius work water opposed metals reduction experiments th century chemists worked catalysis eilhard mitscherlich referred ''contact'' processes johann


wolfgang bereiner spoke ''contact action ''he developed bereiner 's lamp lighter based hydrogen platinum sponge became commercial success lives today humphry davy discovered use platinum catalysis wilhelm ostwald leipzig university started systematic investigation reactions catalyzed presence acids bases found chemical reactions occur finite rates rates used determine strengths acids bases work ostwald awarded nobel prize

Natural science
Chemistry
Chemical Engineering
Catalysis


chemistry vladimir ipatieff performed earliest industrial scale reactions including discovery commercialization oligomerization development catalysts hydrogenation inhibitors poisons promoters added substance reduce reaction rate reaction inhibitor reversible catalyst poisons irreversible ref name iupacc promoters substances increase catalytic activity even though catalysts inhibitors sometimes referred negative catalysts since decrease reaction rate ref name laidler however term inhibitor preferred since work introducing reaction path


higher activation energy would reduce rate since reaction would continue occur non catalyzed path instead act either deactivating catalysts removing reaction intermediates free radicals ref name laidler laidler kj ''physical chemistry biological applications'' benjamin cummings pp ref ref name lm laidler kj meiser jh ''physical chemistry'' benjamin cummings p ref heterogeneous catalysis coking inhibits catalyst becomes covered polymeric side products inhibitor may modify selectivity addition rate instance reduction alkynes alkenes palladium pd catalyst partly poisoned lead ii


acetate pb chco used ref name lindlar ref without deactivation catalyst alkene produced would reduced alkane inhibitor produce effect eg selectively poisoning certain types active sites another mechanism modification surface geometry instance hydrogenation operations large planes metal surface function sites hydrogenolysis catalysis sites catalyzing hydrogenation unsaturates smaller thus poison covers surface randomly tend reduce number uncontaminated large planes leave proportionally smaller sites free thus changing hydrogenation vs hydrogenolysis


selectivity many mechanisms also possible promoters cover surface prevent production mat coke even actively remove material eg rhenium platinum platforming aid dispersion catalytic material bind reagents see also references external links https webarchiveorg web http scienceaidcouk chemistry inorganic catalysishtml science aid catalysts page high school level science http acianorgchemietu muenchende wah vortraege catalysispdf wa herrmann technische universit presentation http wwwtuatacjp kameyama alumite catalyst kameyama sakurai laboratory japan http wwwinorganic chemistry catalysiseu inorganic chemistry catalysis group utrecht university netherlands http wwwbiwkuleuvenbe ifc cok homehtm centre surface chemistry catalysis http wwwudeccl carbocat carbons catalysts group university concepcion chile http wwwnsfcentcorg


'''continuum mechanics''' branch mechanics deals mechanical behavior materials modeled continuous mass rather discrete particles french mathematician augustin louis cauchy first formulate models th century explanation continuum model assumes substance object fills space occupies modeling objects way ignores fact matter made atoms continuous however length scales much greater inter atomic distances models highly accurate models used derive

Applied science
Engineering and technology
Mechanical Engineering
Continuum mechanics


differential equations describe behavior objects using physical laws mass conservation momentum conservation energy conservation information material provided constitutive relationships continuum mechanics deals physical properties solids fluids independent particular coordinate system observed physical properties represented tensors mathematical objects property independent coordinate systems coordinate systems allow tensors expressed computationally concept continuum space separates molecules makeup solids liquids gases materials


cracks discontinuities microscopic level physical phenomena however modeled materials exist continuum meaning matter body continuously distributed fills entire space occupies continuum body continually sub divided infinitesimal elements properties bulk material validity continuum assumption may verified theoretical analysis either clear periodicity identified statistical homogeneity ergodicity microstructure exist specifically continuum hypothesis assumption hinges concepts representative


elementary volume separation scales based hill mandel condition condition provides link experimentalist 's theoretician 's viewpoint constitutive equations linear nonlinear elastic inelastic coupled fields well way spatial statistical averaging microstructure separation scales hold one wants establish continuum finer resolution size representative volume element rve statistical volume element sve employed results random continuum fields latter provide micromechanics basis stochastic finite elements sfe


levels sve rve link continuum mechanics statistical mechanics experimentally rve evaluated constitutive response spatially homogeneous specifically fluids knudsen number used assess extent approximation continuity made car traffic introductory example consider car traffic highway one lane simplicity somewhat surprisingly tribute effectiveness continuum mechanics effectively models movement cars via partial differential equation pde density cars familiarity situation empowers us


understand little continuum discrete dichotomy underlying continuum modelling general start modelling define math x math measures distance km along highway math math time minutes math rho xt math density cars highway cars km lane math u xt math flow velocity average velocity cars 'at' position math x math conservation derives pde partial differential equation cars appear disappear consider group cars particular car back group located math x math particular car front located math x b math


total number cars group math display inline n int b rho xt dx math since cars conserved overtaking 'car front back' may become different car math dn dt math via leibniz integral rule math begin align frac dn dt frac dt int b rho xt dx int b frac partial rho partial dx rho bt frac db dt rho frac da dt int b frac partial rho partial dx rho bt u bt rho u int b left frac partial rho partial frac partial partial x rho u right dx end align math integral zero holds groups intervals math ab math way


integral zero intervals integrand zero math x math consequently conservation derives first order nonlinear conservation pde math frac partial rho partial frac partial partial x rho u math positions highway conservation pde applies car traffic also fluids solids crowds animals plants bushfires financial traders observation closes problem previous pde one equation two unknowns another equation needed form well posed problem extra equation typically needed continuum mechanics typically comes experiments


car traffic well established cars typically travel speed depending upon density math u v rho math experimentally determined function math v math decreasing function density example experiments lincoln tunnel found good fit except low density obtained math u v rho ln rho math km hr density cars km thus basic continuum model car traffic pde math frac partial rho partial frac partial partial x rho v rho math car density math rho xt math highway major areas additional area continuum mechanics comprises elastomeric foams exhibit curious hyperbolic stress strain relationship


elastomer true continuum homogeneous distribution voids gives unusual properties formulation models figure configuration continuum body continuum mechanics models begin assigning region three dimensional euclidean space material body math mathcal b math modeled points within region called particles material points different ''configurations'' states body correspond different regions euclidean space region corresponding body 's configuration time math math labeled math kappa mathcal b math particular particle within body particular configuration characterized position vector


br math mathbf x sum x mathbf e math math mathbf e math coordinate vectors frame reference chosen problem see figure vector expressed function particle position math mathbf x math ' 'reference configuration'' example configuration initial time math mathbf x kappa mathbf x math function needs various properties model makes physical sense math kappa cdot math needs continuous time body changes way realistic globally invertible times body cannot


solids fluids assumed continuous bodies means matter fills entire region space occupies despite fact matter made atoms voids discrete therefore continuum mechanics refers point particle continuous body describe point interatomic space atomic particle rather idealized part body occupying point following classical dynamics newton euler motion material body produced action externally applied forces


either side surface euler cauchy 's stress principle body acted upon external contact forces internal contact forces transmitted point point inside body balance action according newton 's third law motion conservation linear momentum angular momentum continuous bodies laws called euler 's equations motion internal contact forces related body 's deformation constitutive equations internal contact forces may mathematically described relate motion body independent body 's material makeup


distribution internal contact forces throughout volume body assumed continuous therefore exists ''contact force density'' ''cauchy traction field'' math mathbf mathbf n mathbf x math represents distribution particular configuration body given time math math vector field depends position math mathbf x math particular material point also local orientation surface element defined normal vector math mathbf n math differential area math ds math normal vector math mathbf n math


given internal surface area math math bounding portion body experiences contact force math mathbf f c math arising contact portions body side math math given math mathbf f c mathbf mathbf n ds math math mathbf mathbf n math ' 'surface traction'' also called ' 'stress vector'' ''traction'' ''traction vector'' stress vector frame indifferent vector see euler cauchy 's stress principle total contact force particular internal surface math math expressed sum surface integral contact forces differential surfaces math ds math math mathbf f c int mathbf mathbf


n ds math continuum mechanics body considered stress free forces present inter atomic forces ionic metallic van der waals forces required hold body together keep shape absence external influences including gravitational attraction stresses generated manufacture body specific configuration also excluded considering stresses body therefore stresses considered continuum mechanics produced deformation body ' 'sc'' relative changes stress considered absolute values stress body forces ''body forces''


forces originating sources outside body act volume mass body saying body forces due outside sources implies interaction different parts body internal forces manifested contact forces alone forces arise presence body force fields ''eg'' gravitational field gravitational forces electromagnetic field electromagnetic forces inertial forces bodies motion mass continuous body assumed continuously distributed force originating mass also continuously


distributed thus body forces specified vector fields assumed continuous entire volume body ''ie'' acting every point body forces represented body force density math mathbf b mathbf x math per unit mass frame indifferent vector field case gravitational forces intensity force depends proportional mass density math mathbf rho mathbf x math material specified terms force per unit mass math b math per unit volume math p math two specifications


related material density equation math rho b p math similarly intensity electromagnetic forces depends upon strength electric charge electromagnetic field total body force applied continuous body expressed math mathbf f b int v mathbf b dm int v rho mathbf b dv math body forces contact forces acting body lead corresponding moments force torques relative given point thus total applied torque math mathcal math origin given math mathcal mathbf c mathbf b math certain situations commonly considered analysis mechanical behavior


materials becomes necessary include two types forces ''couple stresses'' surface couples contact torques ''body moments'' couple stresses moments per unit area applied surface body moments body couples moments per unit volume per unit mass applied volume body important analysis stress polarized dielectric solid action electric field materials molecular structure taken consideration ''eg'' bones solids action external magnetic field dislocation theory


metals materials exhibit body couples couple stresses addition moments produced exclusively forces called ''polar materials'' ''non polar materials'' materials moments forces classical branches continuum mechanics development theory stresses based non polar materials thus sum applied forces torques respect origin coordinate system body given math mathcal f int v mathbf dm int mathbf ds int v rho mathbf b dv math math mathcal int mathbf r times mathbf ds


int v mathbf r times rho mathbf b dv math kinematics motion deformation figure motion continuum body change configuration continuum body results displacement displacement body two components rigid body displacement deformation rigid body displacement consists simultaneous translation rotation body without changing shape size deformation implies change shape size body initial undeformed configuration math kappa mathcal b math current deformed configuration math kappa mathcal b math figure motion continuum body


continuous time sequence displacements thus material body occupy different configurations different times particle occupies series points space describe path line continuity motion deformation continuum body sense material points forming closed curve instant always form closed curve subsequent time material points forming closed surface instant always form closed surface subsequent time matter within closed surface always remain within


convenient identify reference configuration initial condition subsequent configurations referenced reference configuration need one body ever occupy often configuration math math considered reference configuration math kappa mathcal b math components math x math position vector math mathbf x math particle taken respect reference configuration called material reference coordinates analyzing motion deformation solids flow fluids necessary describe sequence evolution configurations throughout time one description motion made


terms material referential coordinates called material description lagrangian description lagrangian description lagrangian description position physical properties particles described terms material referential coordinates time case '''the reference configuration configuration math math ''' observer standing frame reference observes changes position physical properties material body moves space time progresses results obtained independent choice initial time reference configuration math kappa mathcal b math description normally used


solid mechanics lagrangian description motion continuum body expressed mapping function math chi cdot math figure math mathbf x chi mathbf x math mapping initial configuration math kappa mathcal b math onto current configuration math kappa mathcal b math giving geometrical correspondence ie giving position vector math mathbf x x mathbf e math particle math x math position vector math mathbf x math undeformed reference configuration math kappa mathcal b math occupy current deformed configuration math kappa mathcal b math time math math components math x math called spatial coordinates physical kinematic properties math p ij ldots math ie thermodynamic


properties flow velocity describe characterize features material body expressed continuous functions position time ie math p ij ldots p ij ldots mathbf xt math material derivative property math p ij ldots math continuum may scalar vector tensor time rate change property specific group particles moving continuum body material derivative also known ' 'substantial derivative'' ''comoving derivative'' ''convective derivative'' thought rate property changes measured observer traveling group


particles lagrangian description material derivative math p ij ldots math simply partial derivative respect time position vector math mathbf x math held constant change time thus math frac dt p ij ldots mathbf xt frac partial partial p ij ldots mathbf xt math instantaneous position math mathbf x math property particle material derivative ''instantaneous flow velocity'' math mathbf v math particle therefore flow velocity field continuum given math mathbf v dot mathbf x frac mathbf x dt frac partial chi mathbf xt partial math similarly acceleration field given math mathbf dot mathbf


located initial referenced configuration math kappa mathcal b math case description motion made terms spatial coordinates case called spatial description eulerian description ie '''the current configuration taken reference configuration''' eulerian description introduced d'alembert focuses current configuration math kappa mathcal b math giving attention occurring fixed point space time progresses instead giving attention individual particles move space time approach conveniently applied study fluid flow


kinematic property greatest interest rate change taking place rather shape body fluid reference time mathematically motion continuum using eulerian description expressed mapping function math mathbf x chi mathbf x math provides tracing particle occupies position math mathbf x math current configuration math kappa mathcal b math original position math mathbf x math initial configuration math kappa mathcal b math necessary sufficient condition inverse function exist determinant jacobian matrix often


referred simply jacobian different zero thus math j left frac partial chi partial x j right left frac partial x partial x j right neq math eulerian description physical properties math p ij ldots math expressed math p ij ldots p ij ldots mathbf xt p ij ldots chi mathbf xt p ij ldots mathbf xt math functional form math p ij ldots math lagrangian description form math p ij ldots math eulerian description material derivative math p ij ldots mathbf xt math using chain rule math frac dt p ij ldots mathbf xt frac partial partial p ij ldots mathbf xt frac partial partial x k p ij ldots mathbf xt frac dx k dt math first term right hand side equation gives ''local


rate change'' property math p ij ldots mathbf xt math occurring position math mathbf x math second term right hand side ''convective rate change'' expresses contribution particle changing position space motion continuity eulerian description expressed spatial temporal continuity continuous differentiability flow velocity field physical quantities defined way instant time current configuration function vector position math mathbf x math displacement field vector joining positions particle math p math undeformed configuration


deformed configuration called displacement vector math mathbf u mathbf xt u mathbf e math lagrangian description math mathbf u mathbf xt u j mathbf e j math eulerian description ' 'displacement field'' vector field displacement vectors particles body relates deformed configuration undeformed configuration convenient analysis deformation motion continuum body terms displacement field general displacement field expressed terms material coordinates math mathbf u mathbf xt mathbf b mathbf x mathbf xt mathbf x qquad text qquad u


alpha ij b j x alpha ij x j math terms spatial coordinates math mathbf u mathbf xt mathbf b mathbf x mathbf x mathbf xt qquad text qquad u j b j alpha ji x x j math math alpha ji math direction cosines material spatial coordinate systems unit vectors math mathbf e j math math mathbf e math respectively thus math mathbf e j cdot mathbf e alpha ji alpha ij math relationship math u math math u j math given math u alpha ij u j qquad text qquad u j alpha ji u math knowing math mathbf e alpha ij mathbf e j math math mathbf u mathbf xt u mathbf e u alpha ij mathbf e j u j mathbf e j mathbf u mathbf xt math common


superimpose coordinate systems undeformed deformed configurations results math mathbf b math direction cosines become kronecker deltas ie math mathbf e j cdot mathbf e delta ji delta ij math thus math mathbf u mathbf xt mathbf x mathbf xt mathbf x qquad text qquad u x delta ij x j math terms spatial coordinates math mathbf u mathbf xt mathbf x mathbf x mathbf xt qquad text qquad u j delta ji x x j math governing equations continuum mechanics deals behavior materials approximated continuous certain length time scales


equations govern mechanics materials include balance laws mass momentum energy kinematic relations constitutive equations needed complete system governing equations physical restrictions form constitutive relations applied requiring second law thermodynamics satisfied conditions continuum mechanics solids second law thermodynamics satisfied clausius duhem form entropy inequality satisfied balance laws express idea rate change quantity mass momentum energy


point view shown balance laws mass momentum energy solid written assuming source term zero mass angular momentum equations math begin align dot rho rho boldsymbol nabla cdot mathbf v qquad text balance mass rho dot mathbf v boldsymbol nabla cdot boldsymbol sigma rho mathbf b qquad text balance linear momentum cauchy 's first law motion boldsymbol sigma boldsymbol sigma qquad text balance angular momentum cauchy 's second law motion rho dot e boldsymbol sigma boldsymbol nabla mathbf v boldsymbol nabla cdot mathbf q


rho qquad text balance energy end align math equations math rho mathbf x math mass density current math dot rho math material time derivative math rho math math mathbf v mathbf x math particle velocity math dot mathbf v math material time derivative math mathbf v math math boldsymbol sigma mathbf x math cauchy stress tensor math mathbf b mathbf x math body force density math e mathbf x math internal energy per unit mass math dot e math material time derivative math e math math mathbf q mathbf x math heat flux vector math mathbf x math energy source per unit mass respect reference configuration lagrangian point view


balance laws written math begin align rho det boldsymbol f rho qquad text balance mass rho ddot mathbf x boldsymbol nabla circ cdot boldsymbol p rho mathbf b qquad text balance linear momentum boldsymbol f cdot boldsymbol p boldsymbol p cdot boldsymbol f qquad text balance angular momentum rho dot e boldsymbol p dot boldsymbol f boldsymbol nabla circ cdot mathbf q rho qquad text balance energy end align math math boldsymbol p math first piola kirchhoff stress tensor math rho math mass density reference configuration first piola kirchhoff stress tensor related


qquad text balance energy end align math operators equations defined math boldsymbol nabla mathbf v sum ij frac partial v partial x j mathbf e otimes mathbf e j v ij mathbf e otimes mathbf e j boldsymbol nabla cdot mathbf v sum frac partial v partial x v ii boldsymbol nabla cdot boldsymbol sum ij frac partial ij partial x j mathbf e sigma ijj mathbf e math math mathbf v math vector field math boldsymbol math second order tensor field math mathbf e math components orthonormal basis current configuration also math boldsymbol nabla circ mathbf v sum ij frac partial v partial x j mathbf e otimes mathbf e j v ij mathbf e otimes mathbf e j boldsymbol nabla circ cdot mathbf v


previous section assume flux quantity source quantity internal density quantity per unit mass quantity interest case entropy thus assume entropy flux entropy source internal mass density math rho math internal specific entropy ie entropy per unit mass math eta math region interest let math omega math region let math partial omega math boundary second law thermodynamics states rate


increase math eta math region greater equal sum supplied math omega math flux internal sources change internal entropy density math rho eta math due material flowing region let math partial omega math move flow velocity math u n math let particles inside math omega math velocities math mathbf v math let math mathbf n math unit outward normal surface math partial omega math let math rho math density matter region math bar q math entropy flux surface math r math


entropy source per unit mass entropy inequality may written math cfrac dt left int omega rho eta text dv right ge int partial omega rho eta u n mathbf v cdot mathbf n text da int partial omega bar q text da int omega rho r text dv math scalar entropy flux related vector flux surface relation math bar q boldsymbol psi mathbf x cdot mathbf n math assumption incrementally isothermal conditions math boldsymbol psi mathbf x cfrac mathbf q mathbf x r cfrac math math mathbf q math heat flux vector math math energy source per unit mass math math absolute temperature material point math mathbf x math


time math math clausius duhem inequality integral form math cfrac dt left int omega rho eta text dv right ge int partial omega rho eta u n mathbf v cdot mathbf n text da int partial omega cfrac mathbf q cdot mathbf n text da int omega cfrac rho text dv math show entropy inequality may written differential form math rho dot eta ge boldsymbol nabla cdot left cfrac mathbf q right cfrac rho math terms cauchy stress internal energy clausius duhem inequality may written math rho dot e dot eta boldsymbol sigma boldsymbol nabla mathbf v le cfrac mathbf q cdot boldsymbol nabla math applications continuum mechanics solid mechanics fluid mechanics engineering civil engineering mechanical engineering aerospace


engineering biomedical engineering chemical engineering see also bernoulli 's principle cauchy elastic material configurational mechanics curvilinear coordinates equation state finite deformation tensors finite strain theory hyperelastic material lagrangian eulerian specification flow field movable cellular automaton peridynamics non local continuum theory leading integral equations stress physics stress measures tensor calculus tensor derivative continuum mechanics theory elasticity explanatory notes references citations works cited general references external links https persoisimafr gileborg isimathmeca lageulpdf objectivity classical continuum mechanics motions eulerian lagrangian functions deformation gradient lie derivatives velocity addition formula coriolis objectivity gilles leborgne april http wwwisimafr leborgne isimathmeca lageulloidcdvpdf


part iv velocity addition formula objectivity classical mechanics


principles french declaration rights man citizen still constitutional importance '''constitutional law''' body law defines role powers structure different entities within state namely executive parliament legislature judiciary well basic rights citizens federal countries united states canada relationship central government state provincial territorial governments nation states codified constitutions though states ''jus commune'' law


land may consist variety imperative consensual rules may include customary law conventions statutory law judge made law international rules norms constitutional law deals fundamental principles government exercises authority instances principles grant specific powers government power tax spend welfare population times constitutional principles act place limits government prohibiting arrest individual without sufficient cause nations united states india


singapore constitutional law based text document ratified time nation came constitutions notably united kingdom ref name parliament ref rely heavily uncodified rules several legislative statutes constitutional conventions status within constitutional law varies terms conventions cases strongly contested state legal structure constitutional laws considered second order rule making rules making rules exercise power governs relationships judiciary legislature executive bodies authority one


key tasks constitutions within context indicate hierarchies relationships power example unitary state constitution vest ultimate authority one central administration legislature judiciary though often delegation power authority local municipal authorities constitution establishes federal state identify several levels government coexisting exclusive shared areas jurisdiction lawmaking application enforcement federal states notably united states separate parallel federal state judiciaries


hierarchy courts supreme court state india hand one judiciary divided district courts high courts supreme court india human rights human rights civil liberties form crucial part country 's constitution uphold rights individual state jurisdictions like united states france codified constitution bill rights recent example charter fundamental rights european union intended included treaty establishing constitution europe


failed ratified perhaps important example universal declaration human rights un charter intended ensure basic political social economic standards nation state intergovernmental body obliged provide citizens many include governments countries like united kingdom entrenched document setting fundamental rights jurisdictions constitution composed statute case law convention case named ''entick v carrington'' constitutional principle deriving common law john entick 's house searched ransacked


sherriff carrington carrington argued warrant government minister earl halifax valid authority even though statutory provision court order court led lord camden stated blockquote great end men entered society secure property right preserved sacred incommunicable instances taken away abridged public law good whole laws england every invasion private property ever minute trespass


excuse found produced silence books authority defendant plaintiff must judgment blockquote common law civil law jurisdictions share constitutional law underpinnings common law nations commonwealth well united states derive legal systems united kingdom place emphasis judicial precedent ref name garnerusagedef ref ref name blacks thdef ref whereby consequential court rulings especially higher courts source law civil law jurisdictions hand place less emphasis


codified law constitutional otherwise legislative procedure another main function constitutions may describe procedure parliaments may legislate instance special majorities may required alter constitution bicameral legislatures may process laid second third readings bills new law enter force alternatively may requirements maximum terms government keep power holding election study constitutional law constitutional law major focus legal studies research example law students


united states required take class constitutional law first year several law journals devoted discussion constitutional issues rule law doctrine rule law dictates government must conducted according law first established british legal theorist v dicey dicey identified three essential elements british constitution indicative rule law absolute supremacy regular law opposed influence arbitrary power equality law constitution result


ordinary tribunals third general ideas principles constitution supports arise directly judgements precedents issued judiciary may say constitution pervaded rule law ground general principles constitution us result judicial decisions determining rights private persons particular cases brought courts separation powers separation powers often regarded second limb functioning alongside rule law curb powers government many


modern nation states power divided vested three branches government legislature executive judiciary known horizontal separation powers first second harmonised traditional westminster system vertical separation powers decentralisation see also constitutionalism constitution constitutional economics constitutional rights philosophy law public law rechtsstaat rule law references external links


'''cognitive psychology''' scientific study mental processes attention language use memory perception problem solving creativity reasoning cognitive psychology originated break behaviorism held unobservable mental processes outside realm empirical science break came researchers linguistics cybernetics well applied psychology used models mental processing explain human behavior much work derived cognitive psychology integrated branches psychology various modern disciplines cognitive

Social science
Psychology
Cognitive psychology


mind body two separate substances ref name malone malone jc ''psychology pythagoras present'' cambridge massachusetts mit press pp b pp c pp ref time major debates ensued th century regarding whether human thought solely experiential empiricism included innate knowledge rationalism involved debate included george berkeley john locke side empiricism immanuel kant side nativism ref name anderson anderson jr ''cognitive psychology implications'' new york ny worth publishers ref philosophical debate continuing mid


late th century critical time development psychology scientific discipline two discoveries would later play substantial roles cognitive psychology paul broca 's discovery area brain largely responsible language production ref name malone carl wernicke 's discovery area thought mostly responsible comprehension language areas subsequently formally named founders disruptions individual 's language production comprehension due trauma malformation areas come commonly known broca 's aphasia wernicke 's aphasia


main approach psychology behaviorism initially adherents viewed mental events thoughts ideas attention consciousness unobservables hence outside realm science psychology one pioneer cognitive psychology worked outside boundaries intellectual geographical behaviorism jean piaget studied thoughts language intelligence children adults ref name aboutpiaget smith l piaget retrieved http piagetorg aboutpiagethtml ref mid th century three main influences arose would inspire shape cognitive psychology


formal school thought development new warfare technology wwii need greater understanding human performance came prominence problems best train soldiers use new technology deal matters attention duress became areas need military personnel behaviorism provided little insight matters work donald broadbent integrating concepts human performance research recently developed information theory forged way area ref name anderson developments computer science would lead


parallels drawn human thought computational functionality computers opening entirely new areas psychological thought allen newell herbert simon spent years developing concept artificial intelligence ai later worked cognitive psychologists regarding implications ai encouraged conceptualization mental functions patterned way computers handled things memory storage retrieval ref name anderson opened important doorway cognitivism noam chomsky 's critique ref name chomsky chomsky n ''a review skinner 's verbal behavior'' ref behaviorism empiricism generally initiated would


come known cognitive revolution inside psychology criticism behaviorism j bruner j j goodnow g austin wrote study thinking g miller e galanter k pribram wrote famous plans structure behavior year bruner miller founded harvard center cognitive studies institutionalized revolution launched field cognitive science formal recognition field involved establishment research institutions george mandler 's center human information processing mandler described origins


cognitive psychology article journal history behavioral sciences ref name mandler mandler g origins cognitive r evolution journal history behavioral sciences ref ulric neisser put term cognitive psychology common use book ''cognitive psychology'' published ref name neisser neisser u ''cognitive psychology'' englewood cliffs nj prentice hall neisser 's definition page ref neisser 's definition cognition illustrates progressive concept cognitive processes blockquote term cognition refers processes sensory input transformed reduced elaborated stored recovered used


man 's actions experiences result saw remembered believed dynamic psychologist asks follow subject 's goals needs instincts ref name neisser blockquote cognitive processes main focus cognitive psychologists mental processes affect behavior processes include limited following three stages memory sensory memory storage holds sensory information short term memory storage holds information temporarily analysis retrieves information long term memory long term memory holds information extended period time receives information short term memory


attention psychological definition attention state focused awareness subset available perceptual information ref name apa ref key function attention identify irrelevant data filter enabling significant data distributed mental processes ref name anderson example human brain may simultaneously receive auditory visual olfactory taste tactile information brain able consciously handle small subset information accomplished attentional processes ref name anderson attention divided two major attentional systems exogenous control endogenous


understanding mind 's ability focus one message still somewhat aware information taken ear consciously attended example participants wearing earphones may told hearing separate messages ear expected attend information related basketball experiment starts message basketball presented left ear non relevant information presented right ear point message related basketball switch right ear


non relevant information left ear happens listener usually able repeat entire message end attended left right ear appropriate ref name anderson ability attend one conversation face many known cocktail party effect major findings include participants cannot comprehend passages shadowing one passage cannot report content unattended message shadow message better pitches ear different ref name cherry ref however deep


processing occur early sensory processing subjects notice pitch unattended message changed ceased altogether even oriented unattended message name mentioned ref name cherry memory two main types memory short term memory long term memory however short term memory become better understood working memory cognitive psychologists often study memory terms working memory working memory though working memory often thought short term memory clearly defined ability process maintain temporary information


wide range everyday activities face distraction famously known capacity memory plus minus combination memories working memory long term memory one classic experiments ebbinghaus found serial position effect information beginning end list random words better recalled center ref name eb ebbinghaus hermann memory contribution experimental psychology new york teachers college ref primacy recency effect varies intensity based list length ref name eb


memory usually long term memory break three main sub classes three classes somewhat hierarchical nature terms level conscious thought related use ref name balota balota da marsh ej ''cognitive psychology key readings'' new york ny psychology press pp ref procedural memory memory performance particular types action often activated subconscious level requires minimal amount conscious effort procedural memory includes stimulus response type information activated association particular tasks routines etc person using


procedural knowledge seemingly automatically respond particular manner particular situation process ref name balota example driving car semantic memory encyclopedic knowledge person possesses knowledge like eiffel tower looks like name friend sixth grade represent semantic memory access semantic memory ranges slightly extremely effortful depending number variables including limited recency encoding information number associations information frequency access levels meaning deeply


processed encoded ref name balota episodic memory memory autobiographical events explicitly stated contains memories temporal nature one last brushed one 's teeth one one heard major news event episodic memory typically requires deepest level conscious thought often pulls together semantic memory temporal information formulate entire memory ref name balota perception perception involves physical senses sight smell hearing taste touch proprioception well cognitive processes involved interpreting


senses essentially people come understand world around interpretation stimuli early psychologists like edward b titchener began work perception structuralist approach psychology structuralism dealt heavily trying reduce human thought consciousness titchener would called basic elements gaining understanding individual perceives particular stimuli current perspectives perception within cognitive psychology tend focus particular ways human mind interprets stimuli senses interpretations affect behavior example


way modern psychologists approach study perception research done center ecological study perception action university connecticut cespa one study cespa concerns ways individuals perceive physical environment influences navigation environment language psychologists interest cognitive processes involved language dates back carl wernicke proposed model mental processing language current work language within field cognitive psychology varies widely cognitive psychologists


may study language acquisition ref name ramsden ref individual components language formation like phonemes language use involved mood numerous related areas broca 's wernicke 's areas brain critical language significant work done recently regard understanding timing language acquisition used determine child risk developing learning disability study showed effective strategy important making evaluations include relevant information making assessments


factors individual variability socioeconomic status short term long term memory capacity others must included order make valid assessments ref name ramsden metacognition metacognition broad sense thoughts person thoughts specifically metacognition includes things like effective person monitoring performance given task self regulation person 's understanding capabilities particular mental tasks ability apply cognitive strategies much current study regarding metacognition within field cognitive psychology deals application within area


education able increase student 's metacognitive abilities shown significant impact learning study habits one key aspect concept improvement students' ability set goals self regulate effectively meet goals part process also important ensure students realistically evaluating personal degree knowledge setting realistic goals another metacognitive task common phenomena related metacognition include '''d j vu ''' feeling repeated experience '''cryptomnesia ''' generating thought believing unique actually memory


past experience also known unconscious plagiarism '''false fame effect ''' non famous names made famous '''validity effect ''' statements seem valid upon repeated exposure '''imagination inflation ''' imagining event occur increased confidence occur modern perspectives modern perspectives cognitive psychology generally address cognition dual process theory expounded upon daniel kahneman ref name kahneman kahneman perspective judgement choice ''american psychologist'' '' '' ref kahneman differentiated two styles processing calling intuition reasoning intuition system similar


associative reasoning determined fast automatic usually strong emotional bonds included reasoning process kahneman said kind reasoning based formed habits difficult change manipulate reasoning system slower much volatile subject conscious judgments attitudes ref name kahneman applications abnormal psychology following cognitive revolution result many principal discoveries come field cognitive psychology discipline cognitive behavior therapy cbt evolved aaron beck generally regarded father


multiple studies show similar numbers br many respond antidepressants end taking medications various reasons may develop side effects form personal objection taking drugs br beck posits use psychotropic drugs may lead eventual breakdown individual 's coping mechanisms theory person essentially becomes reliant medication means improving mood fails practice coping techniques typically practiced healthy individuals alleviate effects depressive symptoms failing


patient weaned antidepressants often unable cope normal levels depressed mood feel driven reinstate use antidepressants blockquote social psychology many facets modern social psychology roots research done within field cognitive psychology social cognition specific sub set social psychology concentrates processes particular focus within cognitive psychology specifically applied human interactions gordon b moskowitz defines social cognition study mental processes involved perceiving attending remembering thinking


making sense people social world development multiple social information processing sip models influential studies involving aggressive anti social behavior kenneth dodge 's sip model one empirically supported models relating aggression among research dodge posits children possess greater ability process social information often display higher levels socially acceptable behavior type social interaction children affects relationships model asserts five steps individual proceeds evaluating interactions


individuals person interprets cues key reactionary process developmental psychology many prominent names field developmental psychology base understanding development cognitive models one major paradigms developmental psychology theory mind tom deals specifically ability individual effectively understand attribute cognition around concept typically becomes fully apparent children ages essentially child develops tom unable understand around different thoughts


ideas feelings development tom matter metacognition thinking one 's thoughts child must able recognize thoughts turn others possess thoughts one foremost minds regard developmental psychology jean piaget focused much attention cognitive development birth adulthood though considerable challenges parts stages cognitive development remain staple realm education piaget 's concepts ideas predated cognitive revolution inspired


wealth research field cognitive psychology many principles blended modern theory synthesize predominant views today educational psychology modern theories education applied many concepts focal points cognitive psychology prominent concepts include metacognition metacognition broad concept encompassing manners one 's thoughts knowledge thinking key area educational focus realm related self monitoring relates highly well students able evaluate personal knowledge apply strategies


improve knowledge areas lacking ref name reif reif f ''applying cognitive science education thinking learning scientific complex domains'' cambridge massachusetts mit press pp b pp ref declarative knowledge procedural knowledge declarative knowledge persons 'encyclopedic' knowledge base whereas procedural knowledge specific knowledge relating performing particular tasks application cognitive paradigms education attempts augment student 's ability integrate declarative knowledge newly learned procedures effort facilitate accelerated learning ref name reif knowledge organization applications cognitive psychology 's understanding


knowledge organized brain major focus within field education recent years hierarchical method organizing information maps well onto brain 's memory concepts proven extremely beneficial classrooms ref name reif personality psychology cognitive therapeutic approaches received considerable attention treatment personality disorders recent years approach focuses formation believes faulty schemata centralized judgmental biases general cognitive errors cognitive psychology vs cognitive science line cognitive psychology cognitive science


blurry cognitive psychology better understood predominantly concerned applied psychology understanding psychological phenomena cognitive psychologists often heavily involved running psychological experiments involving human participants goal gathering information related human mind takes processes acts upon inputs received outside world information gained area often used applied field clinical psychology cognitive science better understood predominantly concerned much broader scope links philosophy linguistics anthropology neuroscience particularly artificial intelligence could


said cognitive science provides corpus information feeding theories used cognitive psychologists cognitive scientists' research sometimes involves non human subjects allowing delve areas would come ethical scrutiny performed human participants ie may research implanting devices brains rats track firing neurons rat performs particular task cognitive science highly involved area artificial intelligence application understanding mental processes criticisms lack cohesion observers suggested cognitive psychology became


movement intricacies phenomena processes examined meant also began lose cohesion field study ''psychology pythagoras present'' example john malone writes examinations late twentieth century textbooks dealing cognitive psychology human cognition cognitive science like quickly reveal many many varieties cognitive psychology little agreement exactly may domain ref name malone misfortune produced competing models questioned information processing approaches cognitive functioning decision making behavioral sciences controversies early years


cognitive psychology behaviorist critics held empiricism pursued incompatible concept internal mental states however cognitive neuroscience continues gather evidence direct correlations physiological brain activity mental states endorsing basis cognitive psychology however disagreement neuropsychologists cognitive psychologists cognitive psychology produced models cognition supported modern brain science often case advocates different cognitive models form dialectic relationship one another thus affecting empirical research researchers siding favorite theory example advocates


''mental model theory'' attempted find evidence deductive reasoning based image thinking advocates ''mental logic theory'' tried prove based verbal thinking leading disorderly picture findings brain imaging brain lesion studies theoretical claims put aside evidence shows interaction depends type task tested whether visuospatial linguistical orientation also aspect reasoning covered either theory ref name goel ref similarly neurolinguistics found easier make


divided along lines generative grammar cognitive linguistics affects adjacent research fields including language development language acquisition ref name shatz ref major research areas div style display inline block '''categorization''' induction acquisition judgement classification representation structure similarity '''knowledge representation''' dual coding theories media psychology mental imagery numerical cognition propositional encoding '''language''' language acquisition language processing div div style display inline block '''memory''' aging memory autobiographical memory childhood memory constructive memory emotion memory episodic memory eyewitness memory false memories flashbulb memory list memory biases long term memory semantic memory short term memory source monitoring error spaced repetition working memory div div style display inline block


'''perception''' attention object recognition pattern recognition perception form perception psychophysics time sensation '''thinking''' choice nbsp glasser 's theory concept formation decision making logic psychology reasoning problem solving div influential cognitive psychologists john r anderson alan baddeley david ausubel albert bandura frederic bartlett elizabeth bates aaron beck robert bjork gordon h bower donald broadbent jerome bruner susan carey noam chomsky fergus craik antonio damasio hermann ebbinghaus albert ellis k anders ericsson william estes eugene galanter vittorio gallese michael gazzaniga dedre gentner vittorio guidano philip johnson laird daniel kahneman nancy kanwisher eric lenneberg alan leslie willem levelt elizabeth loftus alexander luria brian macwhinney george


theory personal information management post rationalist cognitive therapy psychological adaptation rubicon model psychology situated cognition social cognition water level task references reading philip quinlan philip quinlan ben dyson ''cognitive psychology'' publisher pearson prentice hall robert j sternberg jeff mio jeffery scott mio publisher cengage learning nick braisby angus gellatly ''cognitive psychology'' publisher oxford university press external links http wwwscholarpediaorg article cognitive psychology cognitive psychology article scholarpedia https wwwhumancornelledu hd research labs lrdm home laboratory rational decision making introductions cognition behavioural sciences


widely used design new drugs materials examples properties structure ie expected positions constituent atoms absolute relative interaction energies electronic charge density distributions dipoles higher multipole moments vibrational frequencies reactivity spectroscopic quantities cross sections collision particles methods used cover static dynamic situations cases computer time resources memory disk space increase rapidly size system studied system one molecule group molecules

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solid computational chemistry methods range approximate highly accurate latter usually feasible small systems ''ab initio'' methods based entirely quantum mechanics basic physical constants methods called empirical semi empirical use additional empirical parameters ''ab initio'' semi empirical approaches involve approximations range simplified forms first principles equations easier faster solve approximations limiting size system example periodic boundary conditions fundamental approximations underlying equations required achieve solution


example ''ab initio'' calculations make born oppenheimer approximation greatly simplifies underlying schr dinger equation assuming nuclei remain place calculation principle ''ab initio'' methods eventually converge exact solution underlying equations number approximations reduced practice however impossible eliminate approximations residual error inevitably remains goal computational chemistry minimize residual error keeping calculations tractable cases details electronic structure less important


building founding discoveries theories history quantum mechanics first theoretical calculations chemistry walter heitler fritz london using valence bond theory books influential early development computational quantum chemistry include linus pauling e bright wilson 's ''introduction quantum mechanics applications chemistry'' eyring walter kimball 's ''quantum chemistry'' heitler 's ''elementary wave mechanics applications quantum chemistry'' later coulson 's textbook ''valence'' served primary references chemists decades


follow development efficient computer technology solutions elaborate wave equations complex atomic systems began realizable objective early first semi empirical atomic orbital calculations performed theoretical chemists became extensive users early digital computers one major advance came paper reviews modern physics clemens c j roothaan largely lcao mo approach linear combination atomic orbitals molecular orbitals many years second cited paper journal detailed account


use united kingdom given smith sutcliffe first ''ab initio'' hartree fock method calculations diatomic molecules performed mit using basis set slater orbitals diatomic molecules systematic study using minimum basis set first calculation larger basis set published ransil nesbet respectively first polyatomic calculations using gaussian orbitals performed late first configuration interaction calculations performed cambridge edsac computer using gaussian orbitals boys coworkers


bibliography ''ab initio'' calculations published largest molecules included naphthalene azulene abstracts many earlier developments ''ab initio'' theory published schaefer h ckel method calculations using simple linear combination atomic orbitals lcao method determine electron energies molecular orbitals electrons conjugated hydrocarbon systems molecules ranging complexity butadiene benzene ovalene generated computers berkeley oxford empirical methods replaced semi empirical methods cndo early efficient ''ab


initio'' computer programs atmol gaussian ibmol polyaytom began used speed ''ab initio'' calculations molecular orbitals four programs gaussian vastly expanded still use many programs use time methods molecular mechanics mm force field developed primarily norman allinger one first mentions term ''computational chemistry'' found book ''computers role physical sciences'' sidney fernbach abraham haskell taub state seems


studies used find starting point laboratory synthesis assist understanding experimental data position source spectroscopic peaks computational studies used predict possibility far entirely unknown molecules explore reaction mechanisms readily studied via experiments thus computational chemistry assist experimental chemist challenge experimental chemist find entirely new chemical objects several major areas may distinguished within computational chemistry prediction molecular structure molecules use simulation forces accurate quantum


chemical methods find stationary points energy surface position nuclei varied storing searching data chemical entities see chemical databases identifying correlations chemical structures properties see ''quantitative structure property relationship'' qspr ''quantitative structure activity relationship'' qsar computational approaches help efficient synthesis compounds computational approaches design molecules interact specific ways molecules eg drug design catalysis accuracy computational chemistry ''exact'' description real life chemistry mathematical models physical laws nature provide


us approximation however majority chemical phenomena described certain degree qualitative approximate quantitative computational scheme molecules consist nuclei electrons methods quantum mechanics apply computational chemists often attempt solve non relativistic schr dinger equation relativistic corrections added although progress made solving fully relativistic dirac equation principle possible solve schr dinger equation either time dependent time independent form appropriate problem hand practice possible except small systems


therefore great number approximate methods strive achieve best trade accuracy computational cost accuracy always improved greater computational cost significant errors present ab initio models comprising many electrons due computational cost full relativistic inclusive methods complicates study molecules interacting high atomic mass unit atoms transitional metals catalytic properties present algorithms computational chemistry routinely calculate properties small molecules contain electrons errors energies less kj mol geometries


bond lengths predicted within picometers bond angles within degrees treatment larger molecules contain dozen atoms computationally tractable approximate methods density functional theory dft dispute within field whether latter methods sufficient describe complex chemical reactions biochemistry large molecules studied semi empirical approximate methods even larger molecules treated classical mechanics methods use called molecular mechanics mm qm mm methods small parts large complexes


displacements lead increase energy local minimum lowest called global minimum corresponds stable isomer one particular coordinate change leads decrease total energy directions stationary point transition structure coordinate reaction coordinate process determining stationary points called geometry optimization determination molecular structure geometry optimization became routine efficient methods calculating first derivatives energy respect atomic coordinates became


available evaluation related second derivatives allows prediction vibrational frequencies harmonic motion estimated importantly allows characterization stationary points frequencies related eigenvalues hessian matrix contains second derivatives eigenvalues positive frequencies real stationary point local minimum one eigenvalue negative ie imaginary frequency stationary point transition structure one eigenvalue negative stationary point complex one usually


little interest one found necessary move search away experimenter looking solely local minima transition structures total energy determined approximate solutions time dependent schr dinger equation usually relativistic terms included making use born oppenheimer approximation allows separation electronic nuclear motions thereby simplifying schr dinger equation leads evaluation total energy sum electronic energy fixed nuclei positions repulsion energy nuclei


notable exception certain approaches called direct quantum chemistry treat electrons nuclei common footing density functional methods semi empirical methods variants major theme large systems relative total energies compared using molecular mechanics ways determining total energy predict molecular structures ''ab initio'' methods programs used computational chemistry based many different quantum chemical methods solve molecular schr dinger equation associated molecular hamiltonian methods include empirical semi empirical parameters equations nbsp derived


conversion isomers determined without full knowledge complete surface particularly important objective called computational thermochemistry calculate thermochemical quantities enthalpy formation chemical accuracy chemical accuracy accuracy required make realistic chemical predictions generally considered nbsp kcal mol nbsp kj mol reach accuracy economic way necessary use series post hartree fock methods combine results methods called quantum chemistry composite methods density functional methods density functional theory dft methods often


considered ''ab initio methods'' determining molecular electronic structure even though many common functionals use parameters derived empirical data complex calculations dft total energy expressed terms total one electron density rather wave function type calculation approximate hamiltonian approximate expression total electron density dft methods accurate little computational cost methods combine density functional exchange functional hartree fock exchange term termed hybrid functional methods semi empirical


methods semi empirical quantum chemistry methods based hartree fock method formalism make many approximations obtain parameters empirical data important computational chemistry especially treating large molecules full hartree fock method without approximations costly use empirical parameters appears allow inclusion correlation effects methods primitive semi empirical methods designed even two electron part hamiltonian explicitly included electron systems h ckel method proposed erich h ckel


valence electron systems extended h ckel method proposed roald hoffmann sometimes h ckel methods referred completely emprirical derive hamiltonianyet term empirical methods empirical force fields usually used describe molecular mechanics molecular mechanics many cases large molecular systems modeled successfully avoiding quantum mechanical calculations entirely molecular mechanics simulations example use one classical expression energy compound instance harmonic oscillator constants appearing equations must obtained beforehand experimental data ''ab


initio'' calculations database compounds used parameterization ie resulting set parameters functions called force field crucial success molecular mechanics calculations force field parameterized specific class molecules instance proteins would expected relevance describing molecules class methods applied proteins large biological molecules allow studies approach interaction docking potential drug molecules methods solids computational chemical methods applied solid state physics


problems electronic structure crystal general described band structure defines energies electron orbitals point brillouin zone ab initio semi empirical calculations yield orbital energies therefore applied band structure calculations since time consuming calculate energy molecule even time consuming calculate entire list points brillouin zone chemical dynamics electronic nuclear variables separated within born oppenheimer representation time dependent approach wave packet corresponding


nuclear degrees freedom propagated via time evolution operator physics associated time dependent schr dinger equation full molecular hamiltonian complementary energy dependent approach time independent schr dinger equation solved using scattering theory formalism potential representing interatomic interaction given potential energy surfaces general potential energy surfaces coupled via vibronic coupling terms popular methods propagating wave packet associated molecular geometry split operator technique chebyshev real polynomial multi configuration time dependent hartree method mctdh semiclassical method molecular


dynamics molecular dynamics md use either quantum mechanics molecular mechanics mixture calculate forces used solve newton 's laws motion examine time dependent behaviour systems result molecular dynamics simulation trajectory describes position velocity particles varies time phase point system described positions momenta particles previous time point determine next phase point time integrating newton 's laws motion monte carlo monte carlo


mc generates configurations system making random changes positions particles together orientations conformations appropriate random sampling method makes use called ''importance sampling'' importance sampling methods able generate low energy states enables properties calculated accurately potential energy configuration system calculated together values properties positions atoms quantum mechanics molecular mechanics qm mm qm mm hybrid method attempts combine accuracy quantum


mechanics speed molecular mechanics useful simulating large molecules enzymes interpreting molecular wave functions atoms molecules qtaim model richard bader developed effectively link quantum mechanical model molecule electronic wavefunction chemically useful concepts atoms molecules functional groups bonding theory lewis pairs valence bond model bader demonstrated empirically useful chemistry concepts related topology observable charge density distribution whether measured calculated quantum mechanical


young ''computational chemistry practical guide applying techniques real world problems'' john wiley sons young 's http wwwcclnet cca documents dyoung topics orig compchemhtml introduction computational chemistry specialized journals computational chemistry '' http wwwsciencedirectcom science bookseries annual reports computational chemistry '' ''computational theoretical chemistry'' '' http wwwsciencedirectcom science journal computational theoretical polymer science '' '' http wwwjournalselseviercom computers chemical engineering computers chemical engineering '' ''journal chemical information modeling'' ''journal chemical information modeling'' '' https wwwjstagejstgojp browse jchemsoft journal chemical software '' ''journal chemical theory computation'' ''journal cheminformatics'' ''journal computational chemistry'' '' https wwwjstagejstgojp browse jcac journal computer aided chemistry '' '' https wwwjstagejstgojp browse jccj journal computer chemistry japan '' '' https wwwspringercom chemistry physical chemistry journal journal computer aided


molecular design '' ''journal theoretical computational chemistry'' ''molecular informatics'' ''theoretical chemistry accounts'' external links http cccbdbnistgov nist computational chemistry comparison benchmark database contains database thousands computational experimental results hundreds systems http wwwacscomporg american chemical society division computers chemistry american chemical society computers chemistry division resources grants awards contacts meetings http booksnapedu openbookphprecord id page r cstb report mathematical research materials science opportunities perspectives cstb report http ocwmitedu courses materials science engineering atomistic computer modeling materials sma spring atomistic computer modeling materials sma free mit course https wwwyoutubecom playlistlist plknvwylvx tfblhcvapmvafqqquhb jwf chem computational chemistry free university minnesota course https webarchiveorg web http wwwchemicalvision org pdfs compchempdf


'''cell biology''' also '''cellular biology''' '''cytology''' branch biology studies structure function behavior cells ref name alberts ref living organisms made cells cell basic unit life responsible living functioning organisms cell biology study structural functional units cells cell biology encompasses prokaryotic eukaryotic cells many subtopics may include study cell metabolism cell communication cell cycle biochemistry cell composition study cells performed using several microscopy techniques

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robert hooke termed building block living organisms cells published ''micrographia'' looking piece cork observing cell like structure ref name eb ref however cells dead gave indication actual overall components cell years later anton van leeuwenhoek first analyze live cells examination algae preceded cell theory states living things made cells cells functional structural unit organisms ultimately


concluded plant scientist matthias schleiden ref name eb animal scientist theodor schwann viewed live cells plant animal tissue respectively ref name cell molecular biology ref years later rudolf virchow contributed cell theory adding cells come division pre existing cells ref name cell molecular biology viruses considered cell biology lack characteristics living cell instead studied microbiology subclass virology ref name nature ref techniques cell biology research looks different ways culture manipulate cells outside


living body research human anatomy physiology derive medications techniques cells studied evolved due advancements microscopy techniques technology allowed scientists hold better understanding structure function cells many techniques commonly used study cell biology listed cell culture utilizes rapidly growing cells media allows large amount specific cell type efficient way study cells ref name ref cell culture one major tools used cellular molecular biology


gas phase changes brightness differences ref name confocal microscopy combines fluorescence microscopy imaging focusing light snap shooting instances form image ref name transmission electron microscopy involves metal staining passing electrons cells deflected upon interaction metal ultimately forms image components studied ref name cytometry cells placed machine uses beam scatter cells based different aspects therefore separate based size content cells may also tagged


gfp fluorescence separated way well cell fractionation process requires breaking cell using high temperature sonification followed centrifugation separate parts cell allowing studied separately ref name cell types drawing prokaryotic cell two fundamental classifications cells prokaryotic eukaryotic prokaryotic cells distinguished eukaryotic cells absence cell nucleus membrane bound organelle prokaryotic cells much smaller eukaryotic cells making smallest form life prokaryotic cells include bacteria


flagellum helps cell move ref name ref ribosomes translation rna protein ref name nucleoid holds genetic material circular structure ref name many process occur prokaryotic cells allow survive prokaryotes '''mrna synthesis''' initiated promoter sequence dna template comprising two consensus sequences recruit rna polymerase prokaryotic polymerase consists core enzyme four protein subunits protein assists initiation instance process termed conjugation fertility factor allows


bacteria possess pilus allows transmit dna another bacteria lacks f factor permitting transmittance resistance allowing survive certain environments structure function structure eukaryotic cells diagram animal cell eukaryotic cells composed following organelles nucleus nucleus cell functions genome genetic information storage cell containing dna organized form chromosomes surrounded nuclear envelope includes nuclear pores allowing transportation proteins


inside outside nucleus also site replication dna well transcription dna rna afterwards rna modified transported cytosol translated protein nucleolus structure within nucleus usually dense spherical shape site ribosomal rna rrna synthesis needed ribosomal assembly endoplasmic reticulum er functions synthesize store secrete proteins golgi apparatus structurally endoplasmic reticulum network membranes found throughout cell connected nucleus


membranes slightly different cell cell cell 's function determines size structure er mitochondria commonly known powerhouse cell functions production energy atp within cell specifically place krebs cycle tca cycle production nadh fadh occurs afterwards products used within electron transport chain etc oxidative phosphorylation final production atp golgi apparatus functions process package secrete proteins destination proteins contain


cytoskeleton cytoskeleton structure helps maintain shape general organization cytoplasm anchors organelles within cells makes structure stability cell cytoskeleton composed three principal types protein filaments actin filaments intermediate filaments microtubules held together linked subcellular organelles plasma membrane variety accessory proteins cell membrane cell membrane described phospholipid bilayer also consisted lipids proteins ref name inside bilayer hydrophobic


order molecules participate reactions within cell need able cross membrane layer get cell via osmotic pressure diffusion concentration gradients membrane channels centrioles function produce spindle fibers used separate chromosomes cell division eukaryotic cells may also composed following molecular components chromatin makes chromosomes mixture dna various proteins cilia help propel substances also used sensory purposes cell metabolism cell metabolism necessary production energy


cell therefore survival includes many pathways cellular respiration glucose available glycolysis occurs within cytosol cell produce pyruvate pyruvate undergoes decarboxylation using multi enzyme complex form acetyl coa readily used tca cycle produce nadh fadh sub sub products involved electron transport chain ultimately form proton gradient across inner mitochondrial membrane gradient drive production atp h oxidative phosphorylation ref name ref metabolism plant cells includes photosynthesis simply exact


opposite respiration ultimately produces molecules glucose cell signaling cell signaling cell communication important cell regulation cells process information environment respond accordingly signaling occur direct cell contact endocrine paracrine autocrine signaling direct cell cell contact receptor cell binds molecule attached membrane another cell endocrine signaling occurs molecules secreted bloodstream paracrine signaling uses molecules diffusing two cells communicate autocrine cell sending signal


secreting molecule binds receptor surface forms communication ion channels different types voltage ligand gated ion channels allow outflow inflow molecules ions g protein coupled receptor gpcr widely recognized contain seven transmembrane domains ligand binds extracellular domain ligand binds signals guanine exchange factor convert gdp gtp activate g subunit g target proteins adenyl cyclase phospholipase c ultimately produce secondary messengers


landing pad proteins containing sh domain allowing activation ras involvement map kinase pathway growth development eukaryotic cell cycle process cell division animal cell cycle cells foundation organisms fundamental units life growth development cells essential maintenance host survival organism process cell goes steps cell cycle development involves cell growth dna replication cell division regeneration cell death


cell cycle divided four distinct phases g g g phase cell growth phase makes approximately cycle proliferation cells instigated progenitors cells start identical form essentially become type cells cell signaling induction influence nearby cells determinate type cell become moreover allows cells type aggregate form tissues organs ultimately systems g g phase dna replication


damage repair considered interphase portion cycle phase mitosis cell division portion cycle mitosis composed many stages include prophase metaphase anaphase telophase cytokinesis respectively ultimate result mitosis formation two identical daughter cells cell cycle regulated cell cycle checkpoints series signaling factors complexes cyclins cyclin dependent kinase p cell completed growth process found damaged altered undergoes cell death


either apoptosis necrosis eliminate threat cause organism 's survival cell mortality cell lineage immortality ancestry present day cell presumably traces back unbroken lineage billion years origin life actually cells immortal multi generational cell lineages ref name bernstein bernstein c bernstein h payne c cell immortality maintenance cell division potential prog mol subcell biol pmid ref immortality cell lineage depends maintenance cell division potential potential may


bernstein cell cycle phases cell cycle four stage process cell goes develops divides includes gap g synthesis gap g mitosis cell either restarts cycle g leaves cycle g completing cycle cell progress g terminal differentiation interphase refers phases cell cycle occur one mitosis next includes g g g phase size cell grows contents cells


samples free cells tissue fragments contrast pathology branch histopathology studies whole tissues cytopathology commonly used investigate diseases involving wide range body sites often aid diagnosis cancer also diagnosis infectious diseases inflammatory conditions example common application cytopathology pap smear screening test used detect cervical cancer precancerous cervical lesions may lead cervical cancer cell cycle checkpoints dna damage repair system cell cycle composed


number well ordered consecutive stages result cellular division fact cells begin next stage last one finished significant element cell cycle regulation cell cycle checkpoints characteristics constitute excellent monitoring strategy accurate cell cycle divisions cdks associated cyclin counterparts protein kinases phosphatases regulate cell growth division one stage another cell cycle controlled temporal activation cdks governed cyclin partner interaction phosphorylation particular protein kinases de phosphorylation cdc family phosphatases


chromosomes cell cycle checkpoints surveillance systems keep track cell cycle 's integrity accuracy chronology checkpoint serves alternative cell cycle endpoint wherein cell 's parameters examined desirable characteristics fulfilled cell cycle advance distinct stepsthe cell cycle 's goal precisely copy organism 's dna afterwards equally split cell components two new cells four main stages occur eukaryotes g cell usually active continues grow rapidly g cell growth continues


protein molecules become ready separation dormant times cells gain mass integrate growth factor receptors establish replicated genome prepare chromosome segregation dna replication restricted separate synthesis eukaryotes also known phase mitosis also known phase segregation chromosomes occur ref name giacomello ref dna like every molecule capable undergoing wide range chemical reactions modifications dna 's sequence hand considerably bigger impact modifications cellular constituents


like rnas proteins dna acts permanent copy cell genome erroneous nucleotides incorporated dna replication mutations occur majority dna damage fixed removing defective bases synthesizing excised area hand dna lesions mended reversing damage may effective method coping common types dna damage forms dna damage mended fashion including pyrimidine dimers caused ultraviolet uv light changed insertion methyl


ethyl groups purine ring 's position mitochondrial membrane dynamics mitochondria commonly referred cell 's powerhouses capacity effectively produce atp essential maintain cellular homeostasis metabolism moreover researchers gained better knowledge mitochondria 's significance cell biology discovery cell signaling pathways mitochondria crucial platforms cell function regulation apoptosis physiological adaptability strongly linked cell mitochondrial channel 's ongoing reconfiguration range mechanisms known mitochondrial membrane dynamics include endomembrane fusion


fragmentation separation well ultrastructural membrane remodeling result mitochondrial dynamics regulate frequently choreograph metabolic also complicated cell signaling processes cell pluripotent stem cells proliferation maturation aging mortality mutually post translational alterations mitochondrial apparatus development transmembrane contact sites among mitochondria structures potential link signals diverse routes affect mitochondrial membrane dynamics substantially ref name giacomello mitochondria wrapped two membranes inner mitochondrial membrane imm outer mitochondrial membrane omm distinctive function structure


parallels dual role cellular powerhouses signaling organelles inner mitochondrial membrane divides mitochondrial lumen two parts inner border membrane runs parallel omm cristae deeply twisted multinucleated invaginations give room surface area enlargement house mitochondrial respiration apparatus outer mitochondrial membrane hand soft permeable therefore acts foundation cell signaling pathways congregate deciphered transported mitochondria furthermore omm connects cellular organelles endoplasmic reticulum er lysosomes


endosomes plasma membrane mitochondria play wide range roles cell biology reflected morphological diversity ever since beginning mitochondrial study well documented mitochondria variety forms general ultra structural morphology varying greatly among cells cell cycle response metabolic cellular cues mitochondria exist independent organelles part larger systems also unequally distributed cytosol regulated mitochondrial transport placement meet cell 's localized energy requirements


mitochondrial dynamics refers adaptive variable aspect mitochondria including shape subcellular distribution ref name giacomello autophagy autophagy self degradative mechanism regulates energy sources growth reaction dietary stress autophagy also cleans clearing aggregated proteins cleaning damaged structures including mitochondria endoplasmic reticulum eradicating intracellular infections additionally autophagy antiviral antibacterial roles within cell involved beginning distinctive adaptive immune responses viral bacterial contamination viruses include virulence proteins prevent autophagy others utilize autophagy elements


intracellular development cellular splitting macro autophagy micro autophagy chaperon mediated autophagy three basic types autophagy macro autophagy triggered exclusion membrane incorporates section cytoplasm generating autophagosome distinctive double membraned organelle autophagosome joins lysosome create autolysosome lysosomal enzymes degrading components micro autophagy lysosome vacuole engulfs piece cytoplasm invaginating protruding lysosomal membrane enclose cytosol organelles chaperone mediated autophagy cma protein quality assurance digesting oxidized altered proteins stressful circumstances


supplying amino acids protein denaturation autophagy primary intrinsic degradative system peptides fats carbohydrates cellular structures physiologic stressful situations cellular progression vital upholding correct cellular balance autophagy instability leads variety illness symptoms including inflammation biochemical disturbances aging neurodegenerative due involvement controlling cell integrity modification autophagy lysosomal networks typical hallmark many neurological muscular illnesses result autophagy identified potential strategy prevention treatment various disorders many


disorders prevented improved consuming polyphenol meal result natural compounds ability modify autophagy mechanism seen potential therapeutic option creation double membrane phagophore would known nucleation first step macro autophagy phagophore approach indicates dysregulated polypeptides defective organelles come cell membrane golgi apparatus endoplasmic reticulum mitochondria conclusion autophagocyte phagophore 's enlargement comes end auto phagosome combines lysosomal vesicles formulate auto lysosome degrades encapsulated


biology notes references electronic book electronic cell molecular biology karp th ed external links '' https onlinelibrarywileycom journal aging cell '' https embryoasuedu pages francis harry compton crick francis harry compton crick andrei embryo project encyclopedia https docsgooglecom presentation olbcxt wvub wh wvahpmjuqy z uxrmbpwgrpolho editusp sharing biology resource professor lin


engineering disciplines various extents etymology george e davis article cites james f donnelly mentioning reference chemical engineering relation production sulfuric acid paper however george e davis english consultant credited coined term davis also tried found society chemical engineering instead named society chemical industry davis first secretary ref name swindin ref ref name flavell ref ''history science united states encyclopedia'' puts use term around chemical

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engineering describing use mechanical equipment chemical industry became common vocabulary england profession chemical engineer already common use britain united states history new concepts innovations demonstration model direct methanol fuel cell actual fuel cell stack layered cube shape center image became clear unit operations alone insufficient developing chemical reactors predominance unit operations chemical engineering courses britain united states continued transport phenomena


polymer science paved way age plastics safety hazard developments concerns regarding safety environmental impact large scale chemical manufacturing facilities also raised period ''silent spring'' published alerted readers harmful effects ddt potent insecticide flixborough disaster united kingdom resulted deaths well damage chemical plant three nearby villages bhopal disaster india resulted almost deaths incidents along incidents affected reputation trade industrial


safety environmental protection given focus response icheme required safety part every degree course accredited legislation monitoring agencies instituted various countries france germany united states recent progress advancements computer science found applications designing managing plants simplifying calculations drawings previously done manually completion human genome project also seen major development advancing chemical engineering genetic engineering genomics well chemical engineering principles used


produce dna sequences large quantities concepts chemical engineering involves application several principles key concepts presented plant design construction chemical engineering design concerns creation plans specifications economic analyses pilot plants new plants plant modifications design engineers often work consulting role designing plants meet clients' needs design limited several factors including funding government regulations safety standards constraints dictate plant 's choice process materials equipment plant construction coordinated project engineers project managers depending size investment


chemical engineer may job project engineer full time part time requires additional training job skills act consultant project group usa education chemical engineering graduates baccalaureate programs accredited abet usually stress project engineering education obtained specialized training electives graduate programs project engineering jobs largest employers chemical engineers process design analysis unit operation physical step individual chemical engineering process unit operations


crystallization filtration drying evaporation used prepare reactants purifying separating products recycling unspent reactants controlling energy transfer reactors hand unit process chemical equivalent unit operation along unit operations unit processes constitute process operation unit processes nitration hydrogenation hydrocracking oxidation involve conversion materials biochemical thermochemical means chemical engineers responsible called process engineers process design requires definition equipment types sizes well connected materials


construction details often printed process flow diagram used control capacity reliability new existing chemical factory education chemical engineers first college degree years study stresses principles practices process design skills used existing chemical plants evaluate efficiency make recommendations improvements transport phenomena modeling analysis transport phenomena essential many industrial applications transport phenomena involve fluid dynamics heat transfer mass transfer governed mainly momentum transfer energy transfer


transport chemical species respectively models often involve separate considerations macroscopic microscopic molecular level phenomena modeling transport phenomena therefore requires understanding applied mathematics applications practice alt two computer flat screens showing plant process management application thumb chemical engineers develop economic ways using materials energy chemical engineers use chemistry engineering turn raw materials usable products medicine petrochemicals plastics large scale industrial setting also involved waste management research applied research facets could make extensive use computers chemical engineers may


involved industry university research tasked designing performing experiments create better safer methods production pollution control resource conservation may involved designing constructing plants project engineer chemical engineers serving project engineers use knowledge selecting optimal production methods plant equipment minimize costs maximize safety profitability plant construction chemical engineering project managers may involved equipment upgrades troubleshooting daily operations either full time consulting roles see also related topics ''education


chemical engineers'' english engineering units list chemical engineering societies list chemical engineers list chemical process simulators outline chemical engineering related fields concepts biochemical engineering bioinformatics biological engineering biomedical engineering biomolecular engineering bioprocess engineering biotechnology biotechnology engineering catalysts ceramics chemical process modeling chemical reactor chemical technologist chemical weapons cheminformatics computational fluid dynamics corrosion engineering cost estimation earthquake engineering electrochemistry electrochemical engineering environmental engineering fischer tropsch synthesis fluid dynamics food engineering fuel cell gasification heat transfer industrial catalysts industrial chemistry industrial gas mass transfer materials science metallurgy microfluidics mineral processing molecular engineering nanotechnology natural environment


lccn date lccn lccn last reynolds first terry chapter engineering chemical lccn process engineering engineering disciplines


plot lorenz attractor values double rod pendulum intermediate energy showing chaotic behavior starting pendulum slightly different initial condition would result vastly different trajectory double rod pendulum one simplest dynamical systems chaotic solutions '''chaos theory''' interdisciplinary scientific theory branch mathematics focused underlying patterns deterministic laws highly sensitive initial conditions dynamical systems thought completely random states disorder irregularities chaos theory states within apparent randomness

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chaotic complex systems underlying patterns interconnectedness constant feedback loops repetition self similarity fractals self organization ref name ref butterfly effect underlying principle chaos describes small change one state deterministic nonlinear system result large differences later state meaning sensitive dependence initial conditions metaphor behavior butterfly flapping wings brazil cause tornado texas small differences initial conditions due errors measurements due rounding errors numerical computation yield


behavior principle predicted chaotic systems predictable 'appear' become random amount time behavior chaotic system effectively predicted depends three things much uncertainty tolerated forecast accurately current state measured time scale depending dynamics system called lyapunov time examples lyapunov times chaotic electrical circuits millisecond weather systems days unproven inner solar system million years chaotic systems


uncertainty forecast increases exponentially elapsed time hence mathematically doubling forecast time squares proportional uncertainty forecast means practice meaningful prediction cannot made interval two three times lyapunov time meaningful predictions cannot made system appears random chaos theory method qualitative quantitative analysis investigate behavior dynamic systems cannot explained predicted single data relationships must explained predicted whole continuous data relationships chaotic dynamics map defined


list chaos spontaneous breakdown topological supersymmetry continuous time dynamical systems chaos phenomenon spontaneous breakdown topological supersymmetry intrinsic property evolution operators stochastic deterministic partial differential equations picture dynamical chaos works deterministic models also models external noise important generalization physical point view since reality dynamical systems experience influence stochastic environments within picture long range dynamical behavior associated chaotic dynamics eg butterfly


effect consequence goldstone 's theorem application spontaneous topological supersymmetry breaking sensitivity initial conditions lorenz equations used generate plots variable initial conditions ''x'' ''z'' kept ''y'' changed ''' ''' ''' ''' ''' ''' values math rho math math sigma math math beta math ''' ''' ''' ''' ''' ''' respectively seen graph even slightest difference initial values causes significant changes seconds evolution three cases example sensitive dependence


initial conditions '''sensitivity initial conditions''' means point chaotic system arbitrarily closely approximated points significantly different future paths trajectories thus arbitrarily small change perturbation current trajectory may lead significantly different future behavior ref name sensitivity initial conditions popularly known butterfly effect called title paper given edward lorenz american association advancement science washington dc entitled ''predictability flap butterfly 's wings brazil set


one example maximal lyapunov exponent mle often used determines overall predictability system positive mle usually taken indication system chaotic ref name addition property properties related sensitivity initial conditions also exist include example measure theoretical mixing discussed ergodic theory properties k system ref name werndlcharlotte non periodicity chaotic system may sequences values evolving variable exactly repeat giving periodic behavior starting point sequence however


region pink red regions eventually cloud vertical lines scattered across space topological mixing weaker condition topological transitivity means system evolves time given region open set phase space eventually overlaps given region mathematical concept mixing corresponds standard intuition mixing colored dyes fluids example chaotic system topological mixing often omitted popular accounts chaos equate chaos sensitivity initial conditions however


sensitive dependence initial conditions alone give chaos example consider simple dynamical system produced repeatedly doubling initial value system sensitive dependence initial conditions everywhere since pair nearby points eventually becomes widely separated however example topological mixing therefore chaos indeed extremely simple behavior points except tend positive negative infinity topological transitivity map math f x x math said topologically transitive pair non empty open sets math u v subset x math exists math k


topological transitivity implies existence dense set points ''x'' dense orbits density periodic orbits chaotic system dense periodic orbits means every point space approached arbitrarily closely periodic orbits ref name devaney one dimensional logistic map defined span style white space nowrap ''x'' ''x'' ''x'' span one simplest systems density periodic orbits example math tfrac sqrt math nbsp math tfrac sqrt math nbsp math tfrac sqrt math approximately nbsp nbsp unstable orbit period similar orbits exist periods etc indeed


many cases chaotic behavior found subset phase space cases interest arise chaotic behavior takes place attractor since large set initial conditions leads orbits converge chaotic region easy way visualize chaotic attractor start point basin attraction attractor simply plot subsequent orbit topological transitivity condition likely produce picture entire final attractor indeed orbits shown figure


right give picture general shape lorenz attractor attractor results simple three dimensional model lorenz weather system lorenz attractor perhaps one best known chaotic system diagrams probably one first also one complex gives rise interesting pattern little imagination looks like wings butterfly unlike fixed point attractors limit cycles attractors arise chaotic systems known strange attractors great