Cryogenic Freezing of Dissection SamplesPowerPoint PresentationOverviewProblem StatementBackgroundKey SpecificationsDesign OverviewCooling MechanismThermo CalculationsSlide 10Electronic ControlSpray ChamberFinal Design PreviewSlide 14Slide 15Slide 16Slide 17Slide 18Future AspectsQuestionsCryogenic Freezing of Cryogenic Freezing of Dissection SamplesDissection SamplesGretchen Foltz, Marie Meyer, Kristy Wood, and Jodi ZilinskiBME 400 October 19th, 2001ClientProfessor Barry GanetzkyYoungHo Koh, PhDDepartment of GeneticsUniversity of Wisconsin – MadisonAdvisorMitch TylerDepartment of Biomedical EngineeringDepartment of Rehabilitative MedicineUniversity of Wisconsin - MadisonOverviewOverview•Problem Statement•Background•Key Specifications•Design Overview•Components–Cooling Mechanism–Electrical Control –Spray Chamber•Final Design Preview•Future Aspects•QuestionsProblem StatementProblem StatementTo design a device which is able to:1. Rapidly freeze biological specimens 2. Provide maximum vitrification3. Preserve morphologyBackgroundBackground•Study of Synapses in Drosophilia•Electron Scanning Microscope •Requires New Fixation TechniquesKey SpecificationsKey Specifications•Preservation of Morphology•Rate of Freezing•Cost•Regulation of Cryogen Flow, Temperature, and PressureDesign OverviewDesign OverviewOverall DesignCoolingMechanismElectronicControlSpray ChamberIntegrationAnd TestingPhase IPhase IPhase IIPhase II Phase IIICooling Mechanism •Primary Cryogen = Liquid Nitrogen•Secondary Cryogen = Propane•Component Elements:–Flow Rates–Cryogen Volumes–Length of the Copper TubingP r o p a n eL i q u i dN i t r o g e nThermo CalculationsThermo Calculations•Amount of heat that must be removed for the sample to properly freeze specimen.•Amount of liquid propane needed to extract the heat in the sample.•Amount of liquid nitrogen needed to condense and cool the propane.•Length of copper tubing.Thermo CalculationsVolume of Liquid Propane ~ 20mlVolume of Liquid Nitrogen ~55mlLength of Copper Tubing ~5cmFlask Dimensions ~15x15cmElectronic ControlElectronic ControlC i r c u i t P r o c e s s i n gT h e r m o c o u p l eL C DS e c o n d S o l e n o i dR e l e a s e dY E SN OD i s e n a b l eS o l e n o i d V a l v eE n a b l eS o l e n o i d V a l v eS e c o n d a r y C r y o g e n< - 1 5 0 CN OY E SE n a b l eS o l e n o i d V a l v eD i s e n a b l eS o l e n o i d V a l v eS e n s o r y I n f o r m a t i o nf r o m S e c o n d a r yC r y o g e nP r o p a n e I n l e t P r o p a n e O u t l e tSpray ChamberSpray Chamber•Spray Mechanism•Insulating Materials•Vacuum Pump•Solenoid ValvesS a m p l eN o z z l eF i t t i n gC o p p e rT u b i n gF u l l C o n eS p r a y N o z z l eFinal Design PreviewFinal Design PreviewCopper Tubing5 cmID = 0.4868 cmOD = 0.9970 cmSpray NozzleCopper TubingFlask15 cm15 cm15 cm1 cmFlaskCopper TubingPlatform15 cm5 cm10 cmPlatformFlaskCopper TubingSpray Chamber15 cm15 cm21 cmFuture AspectsFuture Aspects•Complete Engineering Drawings•Build Prototype•Testing•Run a Design of Experiment to Optimize Cryogen Flow•Make Necessary Adjustments to Design for Construction of Final Product•Write Safety Manual for
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