EngineeringQuarterly
WelcometotheEngineeringQuarterly,a newsletterpublished fourtimesperyearby theUniversityofMary SchoolofEngineering. Initwetrytoinclude articlesfromeachofthefiveengineering majorsthatwecurrentlyofferoncampus: ElectricalEngineering,MechanicalEngineering,CivilEngineering,ComputerScience, andConstructionManagement.Theintended audienceoftheEngineeringQuarterlyisengineers,engineeringstudents,engineering alumni,futureengineeringstudents,andpeopleworkinginfieldscloselyrelatedtoengineeringsuchasscience,computing,and mathematics.
InthisissueofEQyouwillreadaboutstudentdesignprojectsfromtheFallsemester, ournewComputerSciencedegreeprogram, ourredesignedcapstonecourseinSeniorDesign,aswellasengineeringproblemstotry andanarticlebyProfessorCarricoaboutEngineeringasaLiberalArtwhichappearedon PrimeMatters primematters.com.Enjoy!
Dr.TerryPilling DeanofEngineeringandengineeringfirmexecutivetoassisthim indevelopingcurriculum,hiringtherightfaculty,anddesigningtheSchoolofEngineering’snewstate-of-the-artfacilityinUniversity Hall,allcarriedoutinanefforttobuildanoutstandingengineeringprogram.Dr.Pillinghas overseenremarkablegrowthoftheSchool, whichnowincludesfivemajorprogramsand welloveronehundredstudents.
Dr.Pillingisanaccomplishedscientist, earninghisBachelorofSciencedegree,with honors,inEngineeringPhysicsandPhysics attheUniversityofSaskatchewan(Saskatoon, Saskatchewan,Canada)in1995,andhisMasterofSciencedegreeinNuclearPhysicsat theSaskatchewanAcceleratorLaboratoryin 1998withresearchontheThresholdPhotoproductionof π-mesonsandChiralPerturbationtheory.
Dr.PillingcompletedhisDoctorof PhilosophydegreeinHighEnergyParticle PhysicsandSuperstringTheoryatNorth DakotaStateUniversityin2002followedbya post-doctoralappointmentasaresearchscientistattheJointInstituteofNuclearResearch inDubna,RussiaandtheInstituteofTheoreticalandExperimentalPhysicsinMoscow, Russia.
Sincethen,hehashadwidely-varying workexperienceacrossphysicsandengineering,includingworkinhighenergyphysics research,bothinternationallyandacrossthe UnitedStates,asanindustryexecutiveinthe windpowerindustry,andasanacademic, publishingmanypeer-reviewedandhighlycitedscientificarticles.
MichaelStorick,RamiDouri,andChandlerOlsondesignedadigitalclockfortheir projectintheir EEL321Electronics I,course.Theclockmakesuseofaninfinity mirror,alargenumberofLED’sintheform of60differentseven-LEDstrips,awooden frame,anLEDmatrixdisplay,andanArduino Megamicrocontroller.
ThispastFall,theUniversityofMary BoardofTrusteesconfirmedtheSchoolof EngineeringastheUniversity’sfifthschool. ThisactionledtotheappointmentofDr. TerryPillingasinauguralDeanoftheSchool ofEngineeringwhichwasannouncedandcelebratedduringtheSchoolofEngineering’s firstalumnieventonNovember20,2020.
TerryPillingbringsnearlytwenty-five yearsofengineering,research,andhighereducationexperiencetotheposition,including thelastfiveyearsattheUniversityofMary asassociateprofessor(2015-2016)ofPhysics andEngineering,andmorerecently,aschair oftheSchoolofEngineering.
ItisfittingthatDr.Pillingbeappointed thefirstdeanoftheSchool,ashehasbeenthe principalarchitectoftheentireprogram.In 2015,theUniversityofMaryannouncedthat itintendedtodevelopaSchoolofEngineering,hiringhimtoleadtheeffort.IntheFall of2016,theUniversitybegantodramatically increasetechnicalcourseofferingsunderDr. Pilling’sdirectionandguidance.Sincethen, hehasspentmanyhoursconsultingwithlocalandregionalengineeringfirms,touringengineeringfacilitiesofothercollegesanduniversities,drawingonhisyearsofexperience asauniversityprofessor,researchscientist,
Dr.TerryPilling’sappointmentasDean oftheSchoolofEngineeringisastrongendorsementofhisleadership,andwe,thefacultyoftheSchoolofEngineering,congratulatehimandlookforwardtoworkingwith himonthecontinuedgrowthanddevelopment ofourprograms.
TheclockhasthesecondsshownbyasequenceofLED’slightinguparoundtheedge aseachsecondpasses,alongwithanhour handandaminutehand,alsomadeoutof LED’s.Thematrixdisplayinthemiddle showsthedate.Allofitisdesignedtohigh accuracywithabatterybackupsothatthe timeanddateremaininsyncovertimeand evenwhentheclocklosespower.Thisisa veryaestheticallypleasingclock,andthecontrolwasdoneusingprogrammedmicrocontrollerstocontrolthehands,dates,andthe outerLED’s.
Engineersarenotonlyproblemsolvers andtroubleshooters,theyarealsoinventors. Ourstudentshavedesignprojectsinvarious coursesthroughouttheirdegreewhichhelp themtoseehowthecoursematerialtheyare learningcanbeincorporatedintoproducts anddevices.Intheirsenioryeartheyhave adiscipline-specificdesigncourseinwhich theymustcompleteadesignfromconception tocompletion.ThisisfollowedbyacrossdisciplinarydesigncourseintheSpringoftheir senioryearinwhichstudentsmusthaveteam membersfromatleasttwodifferentareasof engineeringinvolvedintheirproject.Herewe willdescribesomeoftheexcitingprojectsthat werecompletedintheFall,2020semester. Thestudentscanalsochoosetocontinueto workontheseprojectsthroughouttheSpring, 2021semesteriftheysochoose.
Oneverycleverclock-featureisthemechanismthattheteaminventedtosetthetime anddate.Thedesignincludesasingleknob comingoutoftheframewhichisbothapush
buttonandarheostatturnknob.Whenit ispushedthehandsandthedatedigitswill starttoblink,witheachpushmovingtothe nexthandordigit.Aleftorrightturnofthe knobwilldecreaseorincreasethevalueof thatdigit.
Theoverallcostofmaterialswaslessthan $300
“Onethingwenoticedwhendoingthisprojectwastheplanning tookmostofthetime...We revisedourplanmultipletimes andneverreallysettledonacoherentplan.Attheend,it almostbecamea‘dowhatever works’project.Luckilyeverythingseemedtocometogether intheend(afteranearsleepless night).”
Thestudentsdesignedandfabricatedthe 3DprinterusingT-slotframing,3D-printed parts,steppermotorsandArduinosforcontrol.CommercialSLS3Dprinterstypically retailstartingat$10,000.OurstudentsareendeavoringtocompletetheirdesignthisSpring forunder$1000
BlakeEmmel,PeterCollart,JoshSynder, andHarrisonBentzeldesignedaSelective LaserSintering(SLS)3Dprinterfortheir EME487MechanicalEngineering Design Project.ASLS3Dprinterusesa high-powerlasertobuildplasticandmetal partsfromabedofpowderedprecursormaterialbyselectivelyfusingtracesofthepowderedmaterialtogetherinalayer-by-layer process.TheSLS3Dprinterconsistsof apowdermanagementsystemthatdeposits layersofthepowderedprecursoronthebuild stage,ahigh-powerCO2laserspeciallyselectedforusewithNylonandotherpolymer materials,andagalvomirrorsystemthatreflectsthelaserontothepowderbedandscans itathighspeedalongtheintendedscanning trajectories.
JoshReinerandGabrielZimmerdesigneda3-axisDLSRMotorizedCamera Sliderfortheir EEL480Electrical EngineeringDesign course.Thisisa sliderwhichwasdesignedandconstructed from3Dprintedcomponentsandenablesone toprogramsmoothly-slidingcameratakesin anypatternover180degrees.Theentireapparatusiscontrolledbyanandroidappthatthey wrotewhichallowstheusertoprogramand executethecamerasweepfromtheirphone.
screwsystemsolvestheproblemformotorizedcameraslidercompaniesthatcannotefficientlymoveloadsvertically.Thesystemis builtusinganArduinoNanoasamicrocontrollerwhichconnectstoasmartphoneapp calledBlynkviaanHC-05Bluetoothmodule.WithintheBlynkapp,userscancontrol themotorizedcamerasliderbyenteringthe desireddistanceoflateralmovement,angles ofrotationandtilt,andtimeintervals.The designoftheappallowsforuserstoutilize thesliderforreal-timevideography,andtimelapsephotographywhethertheyneedhorizontal,vertical,orshotsinsomewhereinbetween.Additionally,thecompletedsliderrig weighs6.2pounds(2,810g)withoutthecamera,makingitportableenoughtobringtodifferentlocations.Afterinitialresearch,abasic designwascreatedusingtwoArduinoNano boards.Aprimaryboardwouldconnecttothe mobileappandreceiveinstructionsviaBluetooth,whilealsocontrollingthelateralmotor.Thesecondaryboardwouldconnecttothe primaryusingapairofwirelesstransceivers, whichwouldallowittoreceiveinstructions relayedfromtheprimaryboardandtocontrol therotatingandtiltingmotors.ThemotorselectedwastheNEMA17modelsteppermotor,whichranatapproximately1.5ampsand requiredaminimumoftwelvevoltstorun. Thechosenleadscrewwasafourmillimeter leadandeightmillimeterdiameter.Thissize ofleadallowedforabetterbalancebetween highandlowspeeds,andonlyincreasedthe chanceofpotentialbackdrivingbyapproximatelytenpercent.
Thesystemthattheybuilt,unlikethemotorizedcameraslidersavailableintoday’smarket,achievesthree-axismovementforunder $500dollars.Thissystemallowsusersto performnearlyninety-degreeverticalmotion andvariablespeedhorizontalmotionwiththe stockmotorforstandardDSLRorsmaller cameras.Multiplefeaturesoftheelectrical systemincludearechargeablebatterypack toallowuseofthesystematanylocation, andaBluetoothapplicationoniOSorAndroidforcontrollingtheslider.Thismotorizedcamerasliderisdesignedusingasteppermotordrivenleadscrewforlateralmovement,aswellastwoseparatesteppermotors toallowforfullthreehundredandsixtydegreerotationandverticaltiltingofthecamera.Thesteppermotorthatcontrolsthelead screwisanimportantfactorfortheoverall performanceasitprovidessmootherandmore precisemovement,aswellasdeliveringmore torquecomparedtobeltorstringsystems, whichlowersthechanceofbackdrivingwhen thecameraisbeingmovedvertically.Alead
Snæd´ısDan´ıelsd´ottirandJeffreyStrong designedafeederfororphanlambsintheir EEL480ElectricalEngineering Design course.Thefeederprototypeshows abucketwithacopperheatingcoilinsideit andtwoteatsonthesidewhichwouldfeed
thelambs.Itisdesignedtoeliminatetheproblemofhavingcoldmilkbytheteatsandthe problemofthemilkgettingsour.Ithelpsthe farmertomonitorthelambswithouthaving tospendtoomuchtimepatrolling.
Thesystemthattheybuiltisautonomous, buthasmorefeaturesthatarenecessaryto lambfeedingthananysystemthatisavailableinthemarkettoday.Ithaswarmmilk readyattheteatsothatbabylambsarenot hesitanttodrink.Itisbuilttohaveaseparatestorageunitforthemilkataroomtemperatureandthesystemitself.Theyhavedesignedthesystemwithamultitudeofsensorsandelectronicstofeedanumberofbaby lambswhenevertheyarehungry.Thereisan RFIDscannerthatscansanelectronicIDon theirearsandaflowsensorateachteattogive thefarmerinformationabouttheamounteach lambhasconsumedofmilk.Forfurthermonitoring,thefarmercanalsoseethetemperatureforthewarmmilk.Thathelpsmonitorthe healthofthelambstoseeifalambisdrinkingenough.Thissystemalertsthefarmerif themilkisgettingbadtocleanoutthesystem.Italsoalertsthefarmerifthemilkis runninglowinthestorageunit.Additionally, thetankisdesignedtodetecttheidentityof eachindividualorphanedlambviathelamb’s RFIDtag.Acomputerwillstoretheamount ofmilkconsumedbyeachlamb,therebyenablingonetotrackwhethereachlambisgettingenoughmilktoremainhealthy.Thereis acontroldisplaywhichallowsalloftheprogramminganddatacollectiontobeautomated viaCprogramsandBashscripts.
EverySpringweofferanOSHA30training courseforourEngineeringstudentswhichis alsoopentothegeneralpublic.Theabove picturewastakenduringtheOSHAHazard Communicationclasswhichwasheldatthe endofJanuary.
TheOSHA(OccupationalSafetyand HealthAdministration)30-hourConstruction IndustryOutreachTrainingcourseisacomprehensivesafetyprogramdesignedforanyoneinvolvedintheconstructionindustry. Specificallydevisedforsafetydirectors,foremen,andfieldsupervisors;theprogramprovidescompleteinformationonOSHAcomplianceissues.
ThisyearourCivilEngineeringand ourConstructionManagementstudentswere joinedbyemployeesfromdifferentlocalengineeringandconstructioncompaniesaswell asanumberofthestafffromtheUniversityof MaryPhysicalPlant.
Afterthe30hoursoftrainingeachofthe studentsreceivestheirOSHA30certification.
Thisisagreatopportunityforourworkforceandstudentslearnsidebysideandfrom eachother.Weendedupwithapproximately 20fromworkforcealongwith10students. Wearelookingforwardtomorecourseslike this.
StructuralMechanicsmadeacollaborativeefforttobuildandtestvariousstructuresina WindTunnel.Thistypeofequipmentisused byresearcherstostudytheliftanddrageffects ofstructuresthatencounterhighwindssuch asaircraft,vehicles,andbuildings.Windtunnelscanvaryinsizetotestsmallscaledmodelsortherealstructures.Smallscaledtesting arecommonastheyaretheeconomicaloption,andcanprovideusefulstudiesthrough useofdimensionalanalysis.
Theteamplanstomakeafewimprovementstothedesignincludingportingthe electronicsandcontrollerstoprintedcircuit boardsandthenpursuemarketingopportunities.Theyhaveinvestigatedthecurrentmarketoptionsforsheepandcattlefeedersand theyareconvincedthattheircontainsmore functionalityandcanbebuiltmorecheaply thananythingsimilarthatiscurrentlyavailableinthemarketplace.
MechanicalandCivilEngineeringstudentsin ENR306:FluidMechanics, EME 322:DesignofMachinery,and ECI351:
In EME306 mechanicalandcivilengineeringstudentsbuilta8ftlongWindTunnelthat couldgeneratevariouswindspeeds,house varioustestsubjects,measurehorizontaland verticalforcesactingonthebodybeingtested whenencounteringhighwinds,andmeasure thewindsvelocity.
Theobjectstobetestedweredesignedand builtinmajorspecificcourses EME322 and ECI351.In EME322 mechanicalengineeringstudentsdevelopedairfoilsthatcould adjusttheflapandslatsusinglinkagemechanismstomanipulatetheprofileofthewing. Anaircraftmorphstheshapeofitswingsto controltheamountofliftitcangenerateat differentstagesofflight.Thecivilengineeringstudentsin ECI351 builthousingstructureswithvariousrooftypesindifferentorientationstoincomingwinds.Thisisofinterestforhousinginenvironmentspronetohigh windsandpotentiallytornadoes.Bothsubject typeswerescaleddownmodelsfortesting.
Eachofthegroupstestedtheirstructuresin variousconfigurationsandcaptureddatato calculatecoefficientsofdragandlift.They couldthencomparetheirresultswiththecoefficientvaluesusedinindustrialengineering practices.Fromthisexperimentthestudents cannowutilizetheirunderstandingofwind effectsonstructuresinengineeringdesignand analysis.
Inadditiontocarryingthemostweightaspossible,anotherobjectivewastohavethehighestload-to-weightratio.Oneofthetrusses thatheldall112lbsweighedinat1.236lbs, whichwasthebestload-to-weightratioas well,90.6.Thestudentteamthatdesigned andconstructedthispapertrussconsistedof BenPihl,CaseyAnderson,BenWilson,and ElizabethHershey.Inadditiontothebuilding andtestingtheirbridges,studentsweretasked toputtogetherareportdocumentingtheirdesignandanalysisoftheirbridge.
installMySQL,setupSQLServers,create thediagramforabusiness,suchasaFireworksandCarRentalcompanyusingthediagramtomoveforwardwithcreatingtheentire databaseforthebusiness.Studentsexplore pullinginformation,updates,deletesandjoins fromthedatabaseuseSQLqueries.
Fortheirfirstprojectin ENR203L: EngineeringMechanicsIILab,a sophomorelevelengineeringcourse,students weretaskedtodesign,analyze,andconstruct atrussbridgetospanatwofootgapusing onlya5lbreamofcopypaperandonebottle ofElmersglue.
COMPUTER SCIENCEMOVESTOTHE ENGINEERING SCHOOL ByJENNIFERFENNEWALD
UniversityofMary’sComputerScience programhasundergoneanexcitingmoveto theSchoolofEngineering.Relocatingtothe SchoolofEngineeringhasprovidedopportunitiesforstudentstolearnmanyadditional skillsthatdealwithfoundationsofprogrammingthroughascientificapproachtocomputingandapplicationdevelopment.Inthisarticlewewilloutlinethepartsoftheoriginal programthatwerecarriedoverfromtheGary TharaldsonSchoolofBusiness.Thiswillbe followedbyanarticleoutliningthenewcurriculumaftertheadditionofthenewEngineeringSchoolcomputingcourses.
Inaddition,duringtheirsophomoreyear,studentscreatewebsitesforbusinesses.One suchwebsitewascreatedbyUniversityof Marystudentsforanonprofitgroupforthe centersfordisabilities:.
Studentshadtopredictwheretheirtruss bridgewouldfailundertwodifferentloading conditionsusingthemethodofjointsanalysis. Onlyoneoftheloadconditionswastobeused fortheactualtestandonlyrevealedtothem ontestday.Theirposttestinganalysiswasto examinehowactualfailurecomparedtotheir predictedfailure,andtodiscusswhatcaused anydifferencesbetweentheircalculationsand whathappened.Studentswereinformedthat iftheirtrussheldover100lbsthentheywould receivefullcreditforthebuild/designportionoftheprojectgrade(30%)automatically. Twoteamsaccomplishedthisfeatandboth heldalltheweightthatwasavailablefortesting,112lbs!
IntheComputerSciencepartoftheprogram,whicharethecoursesprefixedbyCSC inthecurriculumoutlinedinthefollowing article,freshmengainstrongprogramming skillsthroughthedevelopmentofsmallbusinessapplications,engineeringcomputingsystems,andalgorithms.Uponthecompletionof thefirstyearofstudies,studentshavecreated manyprogramapplications,includinglearningC#tocreateprogramsinconsolemode andthenuserInterfaceswithVisualStudio. Attheendoftheirfirstsemester,studentshave formedentiresoftwareapplicationsthatcan beusedinasmallerbusiness.
SecondyearstudentslearnmanyprogrammingskillsusingtheC++programminglanguage.Studentsstartthesemesterwriting manyapplicationsinconsolemodeandmove intothesecondsemestercreatingalargeteam application,suchasagame.Thisenablesthe learningofmultipleclasses,security,vectors, inheritance,constructorsandmanyadvanced features.
Ourfinalyearofprogrammingincludes usingJavatocreatelargebusinessapplicationsandgames.Javaisthemostpopular webprogramminglanguage.Itisusedtodevelopwebsitecontent,games,apps,andsoftware.Theseareasareexploredandimplementedintheremainingadvancedcoursesat theUniversityofMary.OneexampleofsoftwaredevelopmentisstudentswroteanaccountinggamecalledCatsMeowthatwaspresentedatanIACBEAccreditationmeeting, providingagreatcollaborationbetweendepartments,allowingforthedevelopmentofa Monopolytypeofgametohelpstudentslearn accounting.Also,UniversityofMary’sAdvancedprogrammingcoursesprovidewiththe opportunitytoworkwithPython,JavaScript, advancedSQLandotherdevelopmenttools suchasC,C++,Assemblylanguage,Flex, Bison,autoconf,Make,git,Androidapplicationdevelopment,operatingsystemsprogramming,andInternetofThings.
Sophomorestudentsacquiremanyskills, suchascreatingentireERDiagramsand DatabasesinAccessandMySQL.Students
IntheFallof2020,theSchoolofEngineeringtookovertheComputerScienceprogramfromtheGaryTharaldsonSchoolof Businessandinstitutednewdegreerequirementswhichweoutlinebelow.Webeginby
listingthecommoncorerequirementsinthe artsandhumanitieswhicharetakenbyallstudentsregardlessoftheirmajor.Wefollowthis withthespecificrequirementsfortheComputerSciencedegree.
CommonCoreRequirements (takenbyallmajors)
FYE122FirstYearExperienceSeminar (withPresident’sSeminar)
ENG121CompositionII
COM110OralCommunication
ART:SELECTONEOFTHEFOLLOWING
ART108IntroductiontoPhotography
ART116IntroductiontoFilm
ART121ArtofRomeandParis(Romecampus)
ART127IntroductiontoDrawing
ART210TopicsinTextileArts
COM200VisualCommunication
ENG140IntroductiontoNarrative
THR105ActingTechniqueI
MUS196IntroductiontoMusic
MUS211ConcertBand(3semesters)
MUS212ConcertChoir(3semesters)
GLOBALSTEWARDSHIP:
POL101ResponsibleCitizenship
andoneofthefollowing:
ANT171CulturalAnthropology
SOC107GeneralSociology
HIS103/104WesternCivilizationand WorldHistoryIorII
ECN101EconomicsofSocialIssues
CTH/HIS330Catholicism&TheModernWorld CLA/HIS311GrandeurofRome(Romecampus) Language(any300levelorabove)
THEOLOGY:
THE120SearchforGod
THE/CTH234Benedict-yesterday&today
PHILOSOPHY:
PHI108SearchforTruth
andoneofthefollowing:
PHI208/308PhilosophicalEthics
PHI/CTH210SearchforHappiness: FaithandReasoninLife.
SENIORASSESSMENT:
HUM499seniorassessment
ComputerScience
DegreeRequirements
CSC106ApplicationSoftwareConcepts
CSC107IntroductiontoProgramming
CSC203ApplicationDesign&Implementation
CSC204ApplicationsDevelopment
CSC300SystemsDevelopmentI-Database
CSC340WebpageDevelopment
CSC356ProgrammingLanguagesI
CSC357ProgrammingLanguagesII
CSC360ComputerArchitecture
CSC457AdvancedProgrammingLanguages
CSC487OperatingSystemEngineering
EEL206CircuitsI
EEL206LCircuitsILab
EEL313CircuitsII
EEL313LCircuitsIILab
EEL452EmbeddedSystems
EEL452LEmbeddedSystemsLab
EEL462DigitalSystemswithLab
ENR101IntroductiontoEngineering
ENR200ComputerApplicationsinEngineering
ENR210ComputerAidedMeasurements
ENR304ComputerAidedAnalysis
ENR419EngineeringDataAnalysis
ENR470EngineeringEthics
ENR488SeniorDesign
MAT209CalculuswithAnalyticGeometryI
MAT210CalculuswithAnalyticGeometryII
MAT211CalculuswithAnalyticGeometryIII
MAT306Combinatorics
MAT312LinearAlgebra
MAT451NumericalAnalysis
PHY251EngineeringPhysicsI
PHY251LEngineeringPhysicsILab
HUM499SeniorCompetencyTesting
TECHNICALELECTIVES:
Anytwo3/400levelcoursesfrom Engineering(ENR,ECI,EEL,EME,CSC)
Math(MAT)
Science(BIO,CHE,GLG,PHY,SCI)
InformationTechnology(ITM)
ComputerInformationSystems(CIS)
PROBLEMSTO TRY
DIGITAL SYSTEMS PROBLEM ByKHALIDOWEIS
Performthefollowingoperationsinthe specifiedbinaryformat
A5CH C28H in12-bit2’sComplement.
GentleReminder:
theverticaldeflection u(r,θ,t) intermsofthe polarcoordinates
Nextweassumethatthefunction u can beseparatedintotheproductofaspatialpart F (r,θ
sothat u = FG.Substitutingthisintoourdifferential equationgives
COMPUTING PROBLEM ByTERRYPILLING
Example: Createafilecalled farm containingtheline pigcowhorse andthencreateafilecalled sale containing thelines
s/pig/cow/g
s/cow/horse/g
s/horse/pig/g
andnowrunthefollowing sed command: sed-fsalefarm toseehowitworks.
Problem: Changethe sale scriptinthe aboveexamplesothattheoutputis cowhorsepig
VIBRATING CIRCULAR MEMBRANE ByTERRYPILLING
ThestudentsinmyENR338Advanced EngineeringMathematicscoursesolvedfor thevibrationsofacircularmembranethis semester.Theproblemisessentiallythatofa sportsstadiumwithacanvasroofwhichstarts outheldupwardinabowlshapebutthen,suddenlythesupportstructurecollapsesanditis freetooscillate.Thewaythatitoscillatesdependsonhowtheunderlingsupportstructure collapses.Alesscatastrophicsituationwould besimplyhavingwindblowacrossthetopof thestructureandseewhattypesofresonant vibrationscanoccurinthecanvas.Ifthewind happenstocauseresonantfrequenciestooccurthenitispossiblethatastructuralcollapse couldoccuraswehaveallseeninthefamous videooftheTacomaNarrowsbridgecollapse.
Inanycasethefirststepintheproblem istousethebalancingoftheverticaltensionforcesinasmallsquarepieceofthematerialwhileassumingaconstanttension, T , andmassdensity, ρ,acrosstheentirematerial.Newton’slawthenleadstothefollowing secondorderpartialdifferentialequationfor
andsincetheleft-handsideonlydependson t andtheright-handsideonlydependson r and θ theyeachmustbeequaltoaconstant whichwechoosetobe k2 (negativesothat thetimedependenceisoscillatoryratherthan exponential)forsomenumber k.Ourequationthensplitsintotwoseparateequations:
Thetimedependentequationiseasilysolved sinceitisnothingbutasimpleharmonicoscillatorequationasthestudentshaveseenin theirdifferentialequationscourseaswellas theirphysicscourses,signalscourses,circuits courses,etc.Hencethesolutionfor G is
G(t)= A cos(λt)+ B sin(λt) wherethearbitraryconstants A and B are fixedbyinitialconditions.
Nextweassumethatthespatialpartalso splitsintotwoseparatefunctions: F (r,θ)= W (r)Q(θ) andplugthatintoourspatialequationabove,leaving
2 = r2 W ∂ 2W ∂r2 + r W ∂W ∂r + r 2k2 andagainsincetheleft-sideisindependentof r andtheright-sideisindependentof θ they musteachbeconstant.Wechoosetheconstanttobe n2 sothatwehaveasplitintothe followingtwoequations
∂ 2Q ∂θ2 + n 2Q =0
r 2 ∂ 2W ∂r2 + r ∂W ∂r +(r 2k2 n 2)W =0 Thesolutiontothefirstequationis
Q(θ)= C1 cos(nθ)+ C2 sin(nθ)
Nowwenoticethat,since θ istheangular coordinateonacircularmembranewemust have Q(θ)= Q(θ +2π) andso
C1 cos(nθ)+ C2 sin(nθ)=
C1 cos(nθ +2nπ)+ C2 sin(nθ +2nπ) theonlywaythatthiscanbetrueisif n isan integer.I.e.wemusthave n =0, 1, 2,... The secondequation,intermsof r,isthen
r 2 ∂ 2W
∂r2 + r ∂W ∂r +(r 2k2 n 2)W =0 with n apositiveinteger.Ifwelet s = rk this equationreducesto
s 2 ∂ 2W
∂s2 + s ∂W ∂s +(s 2 n 2)W =0
whichwerecognizeasBessel’sEquation. Frobenius’Methodgivesthesolutioninterms ofpowerseriesforeach n asBesselfunctions ofthefirstkind:
Jn(s)= sn ∞ m=0
( 1)ms2m
22m+nm!(n + m)! andsooursolutionfor W (r) is
Wn(r)= Jn(kr),n =0, 1, 2,...
Nowtheboundaryconditionofourproblem isthatthecanvasmustbefixedtothewalls ofthecircularbuildingandso,ifthebuilding hasradius R thenwemusthave
u(R,θ,t)=0
andsince W istheonlypartof u(r,θ,t) that dependsontheradiuswemusthave W (R)= 0 andhence Jn(kR)=0.Thus kR = αn where αn isazerooftheBesselfunction Jn Now Jn hasmanyzerosandsoallofthemwill givesolutionstoourboundarycondition.We willlabelthembytheinteger m andwrite
Jn(kR)=0 ⇒ kR = αmn where αmn isthe mthzeroofthe nthBessel function.
Nowifweputalloftheabovetogetherwe havethegeneralsolutionasasumoverallof thespecificsolutions.Hereistheresult
u = ∞
n,m=0
Jn(kr)
[Amn cos(ckt)+ Bmn sin(ckt)]cos(nθ)
+[A∗ mn cos(ckt)+ B∗ mn sin(ckt)]sin(nθ)
andifweusetheinitialconditionthatthevelocitystartsoutaszero(i.e.theroofisusually notmoving),thenoursolutionbecomes:
u = ∞
n,m=0
Jn(kmnr)cos(ckmnt)×
{Amn cos(nθ)+ A∗ mn sin(nθ)}
andthatisthesolutionwhereweneedtokeep inmindthat kmn = αmn/R where αmn are thezerosoftheBesselfunctionswhichcanbe lookedup.Let’sshowanexamplebysetting
m =1, n =1, c2 =1,and R =1 andlook atthevibrationalmodegivenbythesolution u11.Ourequationabovethenreducesto
u11 = J1(α11r)cos(α11t)cos(θ)
where α11 =3 8317 isthefirstzeroof J1.Let usplotthisandseehowthisvibrationalmode looks.Hereisagnuplotscriptthatwillnot onlyplotit,butwillalsoanimatetheplotso wecanseeitmovingovertime.
bessel.gnuplot
set termwxt settitle ”VibratingCircularMembraneSolutionu(t,
CAREER ACADEMY VISIT
TheBismarckPublicSchoolsCareer AcademyTeachersvisitedourEngineering SchoolonFriday,February12,2021.This wasafollowuptoavisitmadebyDr.Pilling totheCareerAcademyinJanuary.
TheCareerAcademy,locatedat1221 CollegeDriveinBismarck,isdesignedfor BismarckPublicSchoolstudentsinthe9th through12thgradesintheBismarck/Mandanarea.Itisanimpressivebuildingfully equippedwithmodernlaboratories,machine andwoodshops,andevenasolarpanelarray!Studentscantakeamultitudeofcourses suchasAviation,Horticulture/Botany(with aGreenHouse),Pre-Engineering/TechEd, MedicalRelatedCareers,CertifiedNursing Assistant,Electronics,GraphicDesign/DigitalDesign,amathclass,andaResource/tutoringroom.TheTechnicalCenter,acrossthe streetfromtheCareerAcademy,housesAutomotiveTechnology,AutoCollision,Welding,andCarpentry.Eachyear,over1400studentsenrollincoursesthatarelistedthroughouttheirwebsite.Classesaretwoperiods longeachdaytoallowforthe“hands-on” techniquesthataredeliveredbyexperienced classroominstructors.
TheUniversityofMarySchoolofEngineeringsharesmuchofthesamehands-on teachingphilosophythatisfollowedbythe CareerAcademyandwehopethatsomeof thegraduatesoftheCareerAcademywill choosetocontinuetheireducationwithus andbecomeEngineers,ComputerScientists, orConstructionManagers.
Wearecurrentlyworkingonasetofdual creditcoursesthatwecouldofferoverthe summertoCareerAcademygraduateswhich willhelptojumpstarttheirdegree.
EMBEDDED SYSTEMSIN AVRASSEMBLY LANGUAGE ByTERRYPILLING
OurSeniorlevelstudentsaretaking EEL461:EmbeddedSystemsII thissemesterandinittheyarelearning theassemblylanguageforAVRmicrocontrollers.Thisisthemicrocontrollertypethat isusedinanArduino.Thestudentsarenot usingArduinos,theyaresimplyusingthe ATmega328P-PUchip,the avra assembler, andflashingthechipwithanFT-232programmerusing avrdude
Overthecourseofthesemestertheywilllearn howtosetthefusebits,controlthetimer/counters,writeinterrupthandlers,writecommunicationsroutinessothatmultiplemicrocontrollerscantalktoeachotheroveraTwoWireInterface,andfinallyputeverythingtogetherina3Dprintedbox.Theresultisa gamewhichconsistsofthreemicrocontrollers andvariousbuttonsandnumericaldisplays whichispackagedmuchlikeaGameboy.
Hereisoneofthefirstbitsofcodetheywrote togetstartedatthebeginningofthesemester.
pushbutton.asm
;compile with :avrapushbutton.asm
;flash with : ;avrdude pm328p ; cstk500v1 ; b57600 ; P/dev/ttyUSB0 ; Uflash:w:pushbutton.hex
.nolist .include”m328Pdef.inc” .list
.deftemp=r16;definer16astemp
rjmpInit;firstlineexecuted
Init:
sertemp; set allbitsintempto1’s. outDDRB,temp;settingabitas1onthe ;DataDirectionI/Oregister ;forPortB,whichisDDRB, ;setsthatpinasoutput,a0 ;wouldsetthatpinasinput ;sohere,allPortBpinsare ;outputs(setto1)
lditemp,0b11111110;loadthe‘immediate’number
;tothetempregister if it ;werejustldthenthesecond ;argumentwouldhavetobea ;memorylocationinstead
outDDRD,temp;copytemptoDDRD,resultis ;thatPD0isinput,therest ;areoutputs clrtemp;allbitsintemp set to0’s outPortB,temp;setallthebits(i.e.pins) ;inPortBto0V
lditemp,0b00000001;loadimmediatenumbertotemp outPortD,temp;movetemptoPortD.PD0has ;apullupresistor ;(i.e.setto5V)sinceit ;hasa1inthatbitthe ;restare0Vsince0’s.
Main: intemp,PinD;PinDholdsthestateof ;PortD,copythistotemp ; if thebuttonisconnected ;toPD0thiswillbe0when ;thebuttonispushed, ;1otherwisesincePD0has ;apullupresistoritis ;normallyat5V outPortB,temp;sendsthe0’sand1’sread ;abovetoPortBthismeans ;wewanttheLEDconnected ;toPB0,whenPD0isLOW,it ;setsPB0toLOWandturnon ;theLED(sincetheother ;sideoftheLEDisconnected ;to5Vandthiswill set PB0 ;to0Vsocurrentwillflow) rjmpMain;loopbacktostartofMain
ThecodeisforapushbuttoncontrolledLED andissortofthe“HelloWorld”programfor assemblylanguagesincea“blink”typeprogram,whichistypicallyusedforthisonan Arduinoisquiteabitmorecomplicatedin assemblylanguage–requiringknowledgeof theTimer/Counters,Interrupts,andOverflow Handlers.
1CCH
C × 160 + C × 161 +1 × 162 =12+12 × 16+1 × 256 = 460D
Sincewearetakingthe2’sComplement,then E34H =460D.Whichisthecorrectanswer.
• ComputingProblem:
Hereisthe sale script: s/pig/blah/ s/horse/pig/ s/cow/horse/ s/blah/cow/ s/llama//
ENGINEERINGASA LIBERAL ART ByJAMESCARRICO
• DigitalSystemsProblem:
A5CH =101001011100 ANegative12-Bit
Numberin2’sComplementRepresentation. Toknowitsdecimalvalueweneedfirsttoto takethe2’scomplementofitscurrentvalue, andthencalculateitsdecimalequivalent.
First:the2’sComplementofA5CH = FFFH A5CH +1= 5A3 +1= 5A4H
NowtheDecimalvalueof5A4H isequalto 4 × 160 + A × 161 +5 × 162 =4+10 × 16+ 5 × 256=1444D
ConsequentlytheValueofA5CH isactually = 1444D
C28H =110000101000 isalsoaNegative Number
Takingthe2’sComplementofC28H willgive us: C28H =001111011000,aPositive
NumberwithHexadecimalvalue:3D8H
TheDecimalValueof3D8H is 8 × 160 + D × 161 +3 × 162 =8+13 × 16+3 × 256=984
ConsequentlytheValueofC28H isactually = 1000D
ThismeansthatwearedoingthefollowingSubtractionoperation: ( 1444D ( 984)D)=( 1444D +(984)D = 60D)
Letusputthebinariestotestandseeifweget thecorrectresult:
A5CH 101001011100 +3D8H 001111011000
E34H 111000110100
Thequestionis:DoesE34H isequalto 460?
Let’ssee:
Weneedtotakethe2’scomplementofE34H
ThisequalsFFFH E34H +1= 1CBH +1=
MostarBridgeinBosniaandHerzegovina Engineeringisanancientdiscipline.Theterm ‘engineer’itselfderivesfromthemedieval Latiningeniator,whichinturnderivesfrom inandgignere,meaningliterally“onewho generatesnewthings.”Thetermisacognate with‘ingenious’andtherebysuggestsinventionguidedbyinsight.Beforeconsidering engineeringinitsmoreprescribedsenseas aprofessionortechnicaldiscipline,Iwould firstliketoconsideritinabroadersense,as beingbothintrinsicallyfulfillingandpartofa generaltrainingofthemind–therebyImean toconsiderengineeringasaliberalart.While thismayseemanoddreflectionuponapracticaldiscipline,itmaybeessentialtoavoiding certainpathologicalpitfalls(bothfortheindividualandsocietyatlarge).
Thestartofthetwentiethcenturywas markedbytechnologicaladvancementand WorldWarI.Forthosewhoexperiencedit –includingJ.R.R.Tolkien,famedauthorand scholar–industrializationandthemechanizationofthebattlefieldwasanimmediatecause ofthedesolationofthecountrysideandthe brutalityofthefighting.Inspiteofthis,it wouldbewrongtoinferthatTolkienwasa Ludditeorwasespeciallycriticaloftechnologyperse.Militarytechnologywasbutone mediumthroughwhichimperialandnationalisticaspirationswereexpressed,andTolkien understoodthis.
Nonetheless,allusionstotechnologyaccompanycriticismofantagonistsinTolkien’s TheLordoftheRings,anditisofinterest heretoconsiderwhy.Inaspecificinstance, TreebeardsaysofSaruman,“Heisplotting tobecomeaPower.Hehasamindofmetal
andwheels;andhedoesnotcareforgrowingthings,exceptasfarastheyservehim forthemoment.”Inthisformulation,wesee thatSaruman’swilltopoweranddisinterestin “growingthings,”exceptasexpendabletools, arealsothemesthataccompanythecritique ofhispreoccupationwithmetalandwheels. Metalandwheelsarethusrepresentativeof Saruman’sdesiretoinstrumentalizeanddominatethethingsaroundhim.Metalandwheels aremoreconducivetoSaruman’spurposebecausetheyareconceivedaslackingintrinsic naturesoftheirown.Thus,inSarumanwe seethatahazardoftechnologicalpursuitsis thattheycanrepresentadisordereddesirefor power.
Inadditiontoprayerandstudy,manuallaborwasalsoincludedinmonasticism’sdaily routines.Thisintegrationarosenotonlyfrom necessity,butalsobecauseitwasunderstood thatlaborwasfelicitousforthesoulandwas theexamplesetbytheapostlesandchurchfathers.
Insomerespect,technologyhasaninherentrelationshiptopower.Technologyextends therealmofpossibility,whichisalwaysin somewaythepurposeofthosewhocreateand useit:thisseemstobeaproperpartofthe appealoftechnologicalpursuitsandtheromanceofinvention.Technicalpursuitsarean expressionofhumanstrivingandvision.Nevertheless,technologicaladvancements,which aregenerallyboonstosociety,mayhaveavarietyofeffects.Thiscanbeseeninindustrialization,whichhasledtomaterialflourishing buthasalsooftenbeentheoccasionofabuse ofdispossessedpeoples(suchasthosewho experiencedEnglishlandenclosures)andhas ledtoaconcerningproductionofgreenhouse gases.Inasimilarway,theinternethasledto unprecedentedconnectivityandaccesstoinformationbuthasalsoaffectedourpolitical processes.Moregenerally,whilegooddesign maybeablessing,baddesigncanbedisastrous.
Withthesignificanteffectsthattechnologyhashadonourlivesandaneverincreasingpopularityofrelatedfields,such asengineering,itisappropriatetoreflecton theultimategoalofeducationintechnicaldisciplines.Itseemsthekindofpersonsuch programsshouldseektogenerateisneithera merefunctionarynoraself-indulgenttechnocrat,butratherissimultaneouslyapotentinnovatorandagenuineservant.Theneedfor thismeldingoftraitsmightberepresentedby theclassicaldichotomyoftheservileandliberalarts.Intheancientworld,theservilearts werepursuedforthesakeofaparticulartrade andcametobeviewedasthepreoccupation ofaservant.Theliberalartswerepursued foramoregeneraltrainingofthemindand werepursuedbyfreecitizenswhocomposed therulingbodiesofsociety.
Traininginaparticularhands-ontrade wasshunnedbytheeliteoflateantiquitybecausesuchaneducationwasperceivedtobe beneaththeirdignity.Christianitygavereneweddignitytohumblerworkandstations duetoChrist’semphasisonserviceandidentificationwiththepoor.Benedictinemonasticismespeciallyintegratedlaborintoitsspirituality:themotto“oraetlabora”(prayer andwork)representedtheessentialbalanceof
monasticlife.Inadditiontoprayerandstudy, manuallaborwasalsoincludedinmonasticism’sdailyroutines.Thisintegrationarose notonlyfromnecessity,butalsobecauseit wasunderstoodthatlaborwasfelicitousfor thesoulandwastheexamplesetbytheapostlesandchurchfathers.
Inadditiontobeingfocusedonmanuallabor,however,Benedictinemonkswerealso welleducated.Muchoftheliteratureofthe ancientworldwaspreservedinBenedictine monasteriesandmuchofthenobilitywere educatedbyBenedictinemonks.Monasteriesdevelopedintorigorousacademiccentersthatlatergaverisetomedievaluniversities.Benedictinemonkswerebrewers,farmers,andshepherds,buttheywerealsojurists,
philosophers,andtheologians.Outofnecessity,innovationswerebornoftheBenedictinewayoflife:forinstance,theCistercians (whomostheavilyemphasizedlaborandselfsufficiency)becameskilledmetallurgistsand architectsandwereearlyadaptersofthewater wheel.Thus,Benedictinemonasticismcombinedexperienceofstudyandpracticallabors.
Tothequestionofthedesiredgoalofeducationintechnicaldisciplines,Benedictine monasticismcanserveassomethingofan image.Studentsshouldbebroadlyeducated andinspiredbutalsogrounded,intimately connectedwiththerealitiesoflifeforthose aroundthem:thesearethetraitsnecessaryfor anewengineertobebothapotentinnovator andagenuineservant.Programsofstudy
guidedbysuchavisionwillnotmerelyproducebetterengineers,butbetterstudentsand betterpeople,aswell.
Thisarticleoriginallyappearedin Prime Matters: primematters.com
ContactInformation
FormoreinformationaboutourengineeringprogramattheUniversityof Maryemail:Engineering@umary.edu
Nextissue:May,2021
