high price increase due to the immobilization of the fuel in the waste fuel nuclear reactor pools.docx

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highpriceincreaseduetotheimmobilizationofthefuelinthewastefuelnuclearreactorpools

velocity,andcurrentdensity.Mathematicallythemodelformsasystemofdifferential-algebraicequations（DAEs）,whichissolvedcomputationally.Themodelisdesignedwithprocess-controlapplicationsinmind,althoughitcancertainlybeappliedmorewidely.Althoughthephysicalmodeliscomputationallyefficient,itisstilltoocostlyforincorporationdirectlyintoreal-timeprocesscontrol.Therefore,system-identificationtechniquesareusedtodevelopreduced-order,locallylinearmodelsthatcanbeincorporateddirectlyintoadvancedcontrolmethodologies,suchasmodelpredictivecontrol（MPC）.Thepaperillustratesthephysicalmodelandthereduced-orderlinearstate-spacemodelwithexamples.

ArticleOutline

Nomenclature

1.Introduction

2.Modeldevelopment

2.1.Fuelflow,overallmasscontinuity

2.2.Fuelflow,speciescontinuityequations

2.3.Fuelflow,thermalenergy

2.4.Anodebi-layermodel

2.5.MEAenergybalance

2.6.Cathodeairconservationequations

2.7.Electrochemistry

3.Implementation

4.Examplemodelresults

4.1.Steady-stateresults

4.2.Transientsimulations

5.LinearidentificationoftheSOFCstack

5.1.Subspacesystemidentification

5.2.Illustrationoflinearsystemidentification

6.Conclusion

References

937

Recentadvancesinnuclearpoweredelectricpropulsionforspaceexploration  OriginalResearchArticle

EnergyConversionandManagement,Volume49,Issue3,March2008,Pages412-435

R.JosephCassady,RobertH.Frisbee,JamesH.Gilland,MichaelG.Houts,MichaelR.LaPointe,ColleenM.Maresse-Reading,StevenR.Oleson,JamesE.Polk,DerrekRussell,AnitaSengupta

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AbstractAbstract|Figures/TablesFigures/Tables|ReferencesReferences

Abstract

Nuclearandradioisotopepoweredelectricthrustersarebeingdevelopedasprimaryinspacepropulsionsystemsforpotentialfutureroboticandpilotedspacemissions.Possibleapplicationsforhigh-powernuclearelectricpropulsionincludeorbitraisingandmaneuveringoflargespaceplatforms,lunarandMarscargotransport,asteroidrendezvousandsamplereturn,androboticandpilotedplanetarymissions,whilelowerpowerradioisotopeelectricpropulsioncouldsignificantlyenhanceorenablesomefutureroboticdeepspacesciencemissions.ThispaperprovidesanoverviewofrecentUShigh-powerelectricthrusterresearchprograms,describingtheoperatingprinciples,challenges,andstatusofeachtechnology.MissionanalysisispresentedthatcomparesthebenefitsandperformanceofeachthrustertypeforhighpriorityNASAmissions.Thestatusofspacenuclearpowersystemsforhigh-powerelectricpropulsionispresented.Thepaperconcludeswithadiscussionofpowerandthrusterdevelopmentstrategiesforfutureradioisotopeelectricpropulsionsystems.

ArticleOutline

Nomenclature

1.Introduction

2.Electricpropulsionfundamentals

2.1.EPfiguresofmerit

2.2.Categoriesofelectricpropulsion

2.2.1.Electrothermalthrusters

2.2.2.Electrostaticthrusters

2.2.3.Electromagneticthrusters

2.2.4.Advancedthrusterconcepts

3.Nuclearelectricpropulsionsystems

3.1.NEPcomponenttechnologies

3.1.1.Reactor

3.1.2.Powerconversion

3.1.3.Heatrejection

3.1.4.Powermanagementanddistribution

4.Recentadvancesinhigh-powerelectricpropulsion

4.1.IonthrustertechnologydevelopmentfortheJupiterIcyMoonsOrbiterproject

4.1.1.JIMOtechnologychallengesforionpropulsion

4.1.2.JIMOionthrusterdevelopment

4.1.3.Highvoltagepropellantisolatorsandinsulators

4.1.4.Ionenginelifemodelingandtesting

4.1.5.Radiationhardenedmaterialsandcomponents

4.1.6.Griddedionpowerprocessingunits

4.1.7.Propellantmanagement

4.2.VeryhighIspthrusterwithanodelayer（VHITAL）

4.2.1.Systemsengineeringadvantages

4.2.2.VHITALtwo-stagetechnology

4.2.3.VHITALtechnologyassessmentandstatus

4.3.Advancedlithium-fedapplied-fieldLorentzforceaccelerator（ALFA2）

4.3.1.Advantagesoflithium-fedMPDthrusters

4.3.2.ALFA2thrusterdesign

4.3.3.Lithiumvaporizorandfeedsystem

4.3.4.ALFA2vehiclestudy

4.4.Nuclearelectricpulsedinductivethruster（NuPIT）

4.4.1.NuPITexperimentaldevelopment

4.4.2.NuPITmissionanalysis

4.4.3.NuPITnumericalmodeling

5.Nuclearelectricpropulsionmissionsanalysis

6.Statusofnuclearspacepowersystems

7.Radioisotopeelectricpropulsion

7.1.REPpowersystems

7.1.1.DirectdriveEP

7.2.REPmissionbenefits

8.Concludingremarks

Acknowledgements

References

Purchase

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938

Simulationofn-qubitquantumsystems.II.Separabilityandentanglement  OriginalResearchArticle

ComputerPhysicsCommunications,Volume175,Issue2,15July2006,Pages145-166

T.Radtke,S.Fritzsche

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Abstract

Studiesontheentanglementofn-qubitquantumsystemshaveattractedalotofinterestduringrecentyears.Despitethecentralroleofentanglementinquantuminformationtheory,however,therearestillanumberofopenproblemsinthetheoreticalcharacterizationofentangledsystemsthatmakesymbolicandnumericalsimulationonn-qubitquantumregistersindispensableforpresent-dayresearch.

Tofacilitatetheinvestigationoftheseparabilityandentanglementpropertiesofn-qubitquantumregisters,herewepresentarevisedversionoftheFeynmanprogramintheframeworkofthecomputeralgebrasystemMaple.InadditiontoallpreviouscapabilitiesofthisMaplecodefordefiningandmanipulatingquantumregisters,theprogramnowprovidesvarioustoolswhicharenecessaryforthequalitativeandquantitativeanalysisofentanglementinn-qubitquantumregisters.Asimpleaccess,inparticular,isgiventoseveralalgebraicseparabilitycriteriaaswellasanumberofentanglementmeasuresandrelatedquantities.Asinthepreviousversion,symbolicandnumericcomputationsareequallysupported.

Programsummary

Titleofprogram:

Feynman

Catalogueidentifier:

ADWE_v2_0

ProgramsummaryURL:

http:

//cpc.cs.qub.ac.uk/summaries/ADWE_v2_0

Programobtainablefrom:

CPCProgramLibrary,Queen'sUniversityofBelfast,N.Ireland

Licensingprovisions:

None

Computersforwhichtheprogramisdesigned:

AllcomputerswithalicenseofthecomputeralgebrasystemMaple[MapleisaregisteredtrademarkofWaterlooMapleInc.]

Operatingsystemsunderwhichtheprogramhasbeentested:

Linux,MSWindowsXP

Programminglanguageused:

Maple10

Typicaltimeandmemoryrequirements:

Mostcommandsactingonquantumregisterswithfiveorlessqubitstake

10secondsofprocessortime（onaPentium4with

2 GHzorequivalent）and5–20MBofmemory.However,storageandtimerequirementscriticallydependonthenumberofqubits,n,inthequantumregistersduetotheexponentialincreaseoftheassociatedHilbertspace.

No.oflinesindistributedprogram,includingtestdata,etc.:

3107

No.ofbytesindistributedprogram,includingtestdata,etc.:

13 859

Distributionformat:

tar.gz

Reasonsfornewversion:

Thefirstprogramversionestablishedthedatastructuresandcommandswhichareneededtobuildandmanipulatequantumregisters.Sincethe（evolutionof）entanglementisacentralaspectinquantuminformationprocessingthecurrentversionaddsthecapabilitytoanalyzeseparabilityandentanglementofquantumregistersbyimplementingalgebraicseparabilitycriteriaandentanglementmeasuresandrelatedquantities.

Doesthisversionsupersedethepreviousversion:

Yes

Natureofthephysicalproblem:

Entanglementhasbeenidentifiedasanessentialresourceinvirtuallyallaspectsofquantuminformationtheory.Therefore,thedetectionandquantificationofentanglementisanecessaryprerequisiteformanyapplications,suchasquantumcomputation,communicationsorquantumcryptography.Uptothepresent,however,themultipartiteentanglementofn-qubitsystemshasremainedlargelyunexploredowingtotheexponentialgrowthofcomplexitywiththenumberofqubitsinvolved.

Methodofsolution:

UsingthecomputeralgebrasystemMaple,asetofprocedureshasbeendevelopedwhichsupportsthedefinitionandmanipulationofn-qubitquantumregistersandquantumlogicgates[T.Radtke,S.Fritzsche,Comput.Phys.Comm.173（2005）91].Theprovidedhierarchyofcommandscanbeusedinteractivelyinordertosimulatethebehaviorofn-qubitquantumsystems（byapplyinganumberofunitaryornon-unitaryoperations）andtoanalyzetheirseparabilityandentanglementproperties.

Restrictionsontothecomplexityoftheproblem:

Thepresentversionoftheprogramfacilitatesthesetupandthemanipulationofquantumregistersbymeansof（predefined）quantumlogicgates;itnowalsoprovidesthetoolsforperformingasymbolicand/ornumericanalysisoftheentanglementforthequantumstatesofsuchregisters.Owingtotherapidincreaseinthecomputationalcomplexityofmulti-qubitsystems,however,thetimeandmemoryrequirementsoftengrowrapidly,especiallyforsymboliccomputations.Thisincreaseofcomplexitylimitstheapplicationoftheprogramtoabout6or7qubitsonastandardsingleprocessor（Pentium4with

2 GHzorequivalent）machinewith

1 GBofmemory.

Unusualfeaturesoftheprogram:

TheFeynmanprogramhasbeendesignedwithintheframeworkofMapleforinteractive（symbolicornumerical）simulationsonn-qubitquantumregisterswithnootherrestrictionthangivenbythememoryandprocessorresourcesofthecomputer.Wheneverpossible,bothrepresentationsofquantumregis