Forensics CoachesSeminar 08
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Transcript of Forensics CoachesSeminar 08
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Science OlympiadForensics EventHints, Tips, Things to Prep
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Whats NewEach team member may bring notesBunsen burnerPS (polystyrene) limited to non-expandedFingerprints8 NCIC classificationsdevelopment techniquesDNAPCR (not cell division)Blood typeABOavian vs mammalian vs reptilian
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OverviewStory arc presentssuspectstypes of evidencewhich exhibit goes w/ which suspectexhibit listTable of Resultsin notes?Crime SceneSuspect 1Suspect 2Suspect 3SuspectsEvidencePowderFiberHairPolyGr 2Gr 2
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Prep the TeamDivide the responsibilitiesTrust each otherPerson 1start the chromatogrampowder testsPerson 2prep the Table of Resultspolymershairfibers
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Make the "Notes" page8" x 11 "allowed 2 sheets this yearhand writtenthere are 2 sides to a sheet of paperTable of Test Results dichotomous keysentomologyflowcharts for testspolymer density
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Make the "Notes" pagetables of expected resultspowderswhich test yields which positive indicationdistinguishing characteristicshairfibersglassformulasRfspatter
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PrepPack the "Kit"see list in Rulesex: thermometernon-mercury (safety clause)does not specify analog or digitalex: test tubes or any devise in which they can perform testspluraltest tubes spot plates, well plateshave enough to run all tests w/o washingwaterproof box for dirty stuffex: paper towelspluraldoes not specify all the same typepack plenty (include enough for cleanup)
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Categories of ExemplarsPowdersPolymersFibersHairChromatographyAny 2(R), 3(S), 4(N) offingerprintsDNAglassentomologyspatterseeds & pollentracks & soilsblood typebullet striations
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Prep - PowdersDevelop a Flowchart
Practice the testschart of results in "Notes"count equipment needed for "Kit"
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SolubleIodine TestHCl TestFlame TestCornstarchCalcium CarbonateCalcium SulfatePosElectrolyticYesBenedict'sNoGlucoseSucroseNegNoPosPospHmild acidAmmoniumChlorideYesHCl TestvinegarsmellSodium AcetatebaseCO2 Testno smellpH10YesSodium ChlorideCalcium NitrateLithium ChloridePotassium Chlorideyellow/orangered/orangecrimsonpurpleFlame TestNoMagnesium Sulfateyellowno effectBoric AcidFlame Testfaint greenblue/green
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Prep - PolymersBurn Test Results
Polymer"Burn" BehaviorPETEBubbles; slow burn; soot; pungentHDPEFast burn; clean; drips flames; white smokeLDPEFast burn; clean; drips flames; white smokePSFast burn; lots of black sootPPSlow burn; some drips flamePVCMelts more than burns; self-extinguishingPMMABright flame; no smokePCSlow burn / smolder; no smell; self-extinguishing
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Prep - PolymersDensity Dichotomous Key
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Prep - FibersMicroscopic Examinationcotton twisted flat ribbon
wool hair; imbricate scales
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Prep - FibersMicroscopic Examinationsilk double ribbon
linen - bamboo
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Prep - FibersMicroscopic Examinationnylon - tri-lobe cross-section
polyester - round cross-section; delustering pits
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Fibers Burn Tests
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Prep - HairHumanMedullary index < 1/3even distribution of pigmentHuman HairsHair Cross-Section
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Prep - HairAnimalMedullary index > 1/2Dogcontinuous medullascales usually not visibleovoid bodiesroot is spade-like
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Prep - HairAnimalMedullary index > 1/2Catuniserial medulla; very largespinous scales root looks frayed
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Prep - HairOther Stuff to Knowcuticle scale patternscoronal (crown like)imbricate (flat; think shingles)spinous (petals; think asparagus tips) medulla patterns (Nationals)tracediscontinuouscontinuousuniserial laddermultiserial ladderamorphous (bubbly)
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Prep - ChromatographyHow to "run" a chromatogramHow to measure Rf
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Prep - ChromatographyTypical chromatograms
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Prep Mass SpectroscopyConsider affinityarea under curve % concentration
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Optional - Fingerprintsarch
tentedarch
loopradialulnar
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Optional - Fingerprintswhorl
centralpocket
doubleloopaccidental
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Optional - FingerprintsMinutiabifurcationtrifurcationridgeislanddotdelta
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Optional - FingerprintsDetectionpowdercyanoacrylate fumingamino acids, fatty acids, proteinsnon-porous surfacesiodine fumingfats, oilsporous surfacesnoxious, corrodes surfacessilver nitratesaltsninhydrinamino acidskills living tissues
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Optional DNA Chromatogram PCR DNA copy machine
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Option - GlassIndex of RefractionHot-Stage MicroscopeStress LinesOrder of fractures
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Option - EntomologyTime Lines
Blow Flylarvamaggotpupaadult
Beetlesusually arrive after blow flies
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Option - SpatterDirectionalityAngle of ImpactDroplet Size
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Option Seeds, pollenvisual microscopic comparison
Option Tracksvisual comparisonsdirectionality
Option Soilscompare compositionmicroscopic examinationsoil triangle
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Option Blood TypeABO blood typeperform antigen testsRBC, WBC, platlethuman vs avian vs reptilian
Option Bulletscomparison of striations
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Science OlympiadForensics EventHints, Tips, Things to Prep
*****Read the rulessingular vs pluralbuild the kit while practicing the tests*Required Groups - 55%Optional Groups 15%Analysis 30%*