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Faizan Zubair & Paul LaibinisMay 27th 2015Use of interactive videos to enhance student understanding of thermodynamic efficiencypresent the problem you were trying to solve; explain what you put together in your module and why you took the approach that you did; explain how you examined the effect of your module on your students learning and what you saw.

1Student conceptual understanding of thermodynamic efficiency is incomplete

CompressorPower Generation CycleEfficiency of Cycle vs. Efficiency of unit Components?Unit ComponentsSystem of Components2Developed online videos explaining the concepts of efficiencyJanFebMarAprPS #3 (Feb 2nd), Monetary Analogy (2 videos)PS #4 (Feb 9th), Efficiency of the Heating ElementPS #6 (Mar 11), Efficiency of the Rankine Cycle91 views135 views185 viewsMonetary analogies for thermodynamic efficiency Video 1 & 2Internal EnergyHeat losses to the surroundingsElectrical energy

Market

Transaction Costs Example: Broker Fees4Compute efficiency of a unit componentVideo 3Internal EnergyHeat losses to the surroundingsElectrical energy

25 W of power for 60 secRaises temp. from 20 C to 50 CCompute efficiency for system of componentsVideo 4Synchronized audio-videoStep-wise approach to problem solvingAssessments for students

Formative assessments as part of the videos

Problem on the Homework AssignmentView the video at https://www.youtube.com/watch?v=uSukYclkQqo&feature=youtu.be&hd=1 and answer the following questions:For the process described in the video employing a 100% and an 80% efficient turbine, the overall process efficiency changed from 36.6% to 29.36%. Determine the percent increase or decrease in the rate of cooling demands for the process caused by the use of the 80% efficient turbine ifa) The rate of heat provided to the process remained the same.b) The net rate of power generation remained the same.c) Determine the overall process efficiency if instead the pump was 80% efficient and the turbine was 100% efficient. Is your result greater than, less than, or the same as the 29.36% in the video? Assessing the effectiveness of the online moduleJanFebMarAprQuiz 4 (Mar 9th)Exam II questions (Mar 19th)Student Attitude Survey (Mar 20th)PS #3 (Feb 2nd), Monetary AnalogyPS #4 (Feb 9th), Efficiency of the Heating ElementPS #6 (Mar 11), Efficiency of the Rankine CycleImplementationAssessmentsQuiz results didnt show difference in student learning

Quiz 4 Total(10 points)20136.4 2.320156.1 2.3Problem 6 (20 points)In Problem 1 on Problem Set 5, you analyzed a 50 MW (megawatt) power plant that operated on the Rankine power generation cycle. The cycle used steam, operated at a pressure of 10 kPa in the condenser and a pressure of 10 MPa in the evaporator, and had a maximum evaporator temperature of 600 C. A solution to this problem is provided with this test on the following pages. If the pump in the original problem was replaced by one that was only 50% efficient, determine the temperature of the steam leaving the turbine = __________________________the flow rate of steam through the plant = __________________________the heat transfer rates in the boiler = ________________________the heat transfer rates in the condenser = ________________________the overall efficiency of the plant. = __________________________Exam question on Power Generation Cycle Administered in 2011 and 2015Student performance on Power Generation Cycle improved in 2015Average Score: 73.0Average Score: 65.0Efficiency and its effect on Flow rates, heat transfer, Temperature11Exam question on Refrigeration CycleAdministered in 2010 and 2015Problem 8 (15 points)A refrigeration unit operates in a dorm room using tetrafluoroethane (HFC-134a) as refrigerant. The temperature in the freezer is maintained at -30 C and the minimum temperature for the condenser is 50 C. A thermodynamic diagram for HFC-134a is provided as the last page of this test.a) If this refrigeration unit operates on a traditional vapor compression refrigeration cycle and uses a throttle valve in its expansion, determine its coefficient of performance (C.O.P.). Assume ideal operation for the compressor. (8 points)C.O.P. = ___________________________________________________b)If the throttle valve is replaced by a maximally efficient expander that transfers the work that it produces to the compressor, determine the coefficient of performance (C.O.P.) for this modified refrigeration unit. Assume ideal operation for the compressor and the expander. (7 points)C.O.P. = ___________________________________________________

Student performance on Refrigeration Cycle improved in 2015Average Score: 73.9Average Score: 54.1Computing coefficient of performance and the effect of efficiency of unit components including throttle valve and compressor13Students found videos to be an effective learning strategyStrongly AgreeAgreeNeutral DisagreeStrongly DisagreeThe videos were an effective way to reinforce thermodynamic concepts20%68%10%2%0%It was helpful to watch the videos on my own time and pace32%58%8%2%0%The material covered in videos related well to concepts covered in class and problem sets28%58%14%0%0%I watched at least one of the videos multiple times to help me understand a particular concept?60% of the students said yes!Student feel confident in their ability to analyze thermodynamic cyclesStrongly AgreeAgreeNeutral DisagreeStrongly Disagree The monetary analogy was useful in understanding thermodynamic efficiency30%48%20%2%0%I am comfortable evaluating the effect of turbine efficiency on the overall efficiency of the heat engine34%54%12%0%0%Students found videos on efficiency calculations to be more helpfulAverage Rank

Understanding Efficiency through Everyday Examples: Gold Coins2.8 1.1Gold Coin Example: Broker Fees and Courier Fees2.8 1.1Computing Efficiency of the Heating Element2.1 0.9

Computing Efficiency of the Heat Engine1.6 1.01 is most useful, 4 is least usefulStudents supported the use of videos for other classesStrongly AgreeAgreeNeutral DisagreeStrongly DisagreeIt will be nice to have more videos to understand other thermodynamic concepts44%48%8%0%0%It will be nice to videos to illustrate concepts in other chemical engineering classes38%54%8%0%0%Suggested topics for videos:Departure FunctionsFugacityEquations of StateGeneralized co-relationsConclusionsUse of online videos improved student performance on calculating efficiency of refrigeration and power cyclesStudent acknowledged the effectiveness of videos in helping them learn- 60% of the students said they watched video multiple timesStudents ranked videos on cycles to be more helpful than those on the building monetary analogyOther topics to cover might be departure functions, fugacity, equations of state and generalized co-relationsAcknowledgementsCenter for TeachingCynthia Brame, Assistant DirectorRhet McDaniel, Educational TechnologistChristian Ehret, Graduate Teaching Fellow

BOLD Cohort GroupDave CaudelEmilianne McCranieUdo ChinyereTy McCleeryMary Keithly

FundingNational Science Foundation grant DUE-1231286 to the CIRTL NetworkWhat other concepts covered in class would you have liked to see on videos?Any suggestions for improving the videos?Departure FunctionsFugacityEquations of StateGeneralized co-relationsIncrease coverage to include other topics such as equation of stateFaster pace; calculations off-camera20-30 second recap in the end

Student conceptual understanding is found lackingChBE 162: Chemical Engineering ThermodynamicsPart of core curriculum for chemical engineering Approx. 60 sophomores take this class every year Students struggle in applying the concept of efficiency to thermodynamic systems Students can use thermodynamic equations to calculate the efficiency for process equipment such a pump or a turbine. However, conceptual understanding is found lacking when students compute efficiencies at a systems level where multiple components function together.

Video on the Monetary Analogy

Synchronized audio-videoStep-wise approach to problem solvingBuilt-in assessments for studentsDevelopmentWacom pen tabletScreencast in CamstasiaDelivered through Hapyak/ YoutubeContentMonetary analogies for thermodynamic efficiencyCompute efficiency for single component systemApply efficiency concepts for multi-component systems

22Any suggestions for improving the videos?Use one page for all the work in summaryHave videos for some of the more difficult concepts, like equations of state and departure functionsI hate to say it since I have awful handwriting, but the handwriting can be difficult to read sometimesLess about efficiency; apply more to actual Chem EThe broker video seemed to be incorrect. The logic was sound but the assumption that you suddenly get more gold rather than less was offThe sometimes get cluttered with scratchworkKeep doing it:)NoThey were very helpfulI thought they helped wish they were more of them. Faster pace, may be do calcuations off camera? Or have things written ahead of timeMore coverage of material Faster pace; Linking to concepts in classThey are fine!Make videos for harder to understand concepts; efficiency is pretty easyMore clarity of voiceNoI will like them to be more interactive and 20-30 second recap in the endThe videos were helpful, but the examples were very straight forward. I'd like to see videos with questions that are tricky to see how to deal with unordinary circumstancesGreen= People thought it was helpful and may be wished there were more of themBlue = Some good suggestions: Do calculations of camera; 20-30 seconds recap of the videos/ using a summary slideOrange = Nit picky: More clarity of voice; handwritingA lot of students thought that the concept of efficiency was relatively easy and asked that more videos be made for more difficult concepts

23OutlineReading assignments Learning/ Online learningLearning: From Speculation to ScienceBuilding from content to community: Rethinking the Transition to Online Teaching and LearningDeveloping a Test of Scientific literacy skillsLearning online tools and technologyWacom Board, Youtube, Hapyak, Camstasia, ScreencastBuilding Online Materials AssessmentsQuestions integrated within the videoHomework problems on the videoExam questions on Test 2ABET Accreditation

Read through the past exams and reProblem: Applying the concept of efficiency to thermodynamic systemsChBE 162 class for sophomore chemical engineering studentsStudents can typically compute the efficiency for single systems such as a turbine or a pumpHowever, for multi-component systems such as a refrigeration system or power station calculating efficiency may be a challengeHypothesisThe concept of efficiency is too abstract for many students. If we can use concrete everyday analogies to illustrate the concept of efficiency, this may enhance conceptual understanding. Examples include:Currency conversionTransaction costs for purchases at Dicks sporting goodsStudent Worker at Barnes and NoblesKey Thermodynamic ConceptsFor an ideal gasTemperature determines internal energy Carnot Cycle, Engine and Efficiency

Thermodynamic ConceptsState variable vs other variableInternal energy; independent of path; only dependent on the position on the PV-diagramPumps vs. TurbineMulti-component systemRefrigeration systemHeat Engine

Key conceptsConcept of weighted average: If you have three different chains and each chain has its own efficiency then the overall efficiency is weighted average of individual chainsThermodynamics is the study of energy conversion from one form into another. We have to convert everything into a common denominatorOutput driven: You start with what you need. You know the efficiency of the process and we back-calculate the amount of inputProcess for Making VideosCamtasia to do voice recordingScreencast-O-Matic (Alternative to Camtasia)Videopad for Video-editing (30 Days Trial)Wacom Board Upload the video on YoutubeUse Hapyak to integrate questionsTest that the responses can be collected for analysisWhat other concepts covered in class would you have liked to see on videos?Finding Pvap for a constant TDeparture Functions, how to tell which v is preferred based on Delta GDeparture functionsUse of Gibbs free Energy to evaluate molar volumes at a specific T,PRankine Cycle was goodFugacity. AlreadyMore Manipulations of Maxwell EquationsDeparture FunctionsDeparture Functions; Generalized CorrelationsApplication of Departure Functions- Class material is theory-heavyFugacityHow to deal with cubic equation of state curvesDeparture functionsFugacity, a refrigeration cycle would be nice, basically every topicDeparture functions; involving diff EOSDelta G; (Graph of P and V)Solving sample problems on delta m departureDeparture function derivationsDeparture FunctionsRelating thermodynamic expressions to specific EOS; Determining v from cubic EOS using Gibbs free energyDeparture function derivations; use of P vs. v plot and finding valuesEntropyGibbs free energyExamples with EOSDeparture Functions: how do real materials deviate from ideal behaviorGeneralized correlation; manipulation of maxwell equationsI look at it positively in that there is demand for more videos32ContThe different EOS functions and the various methods for finding delt H - for example generalized corelationsDeparture functions for entropyDeparture functions and calcuations from an EOSmore coverage of materialDeparture function examples Gibbs Free Energy Departure Function; Gibbs free energy Evaluation equation of state for certain departure functionsThe Departure delta s, h, and vMaking departure function calcuating easierGeneralized Correlation of delta H, Delta S, Delta uGeneralized CorrelationQuality Calcuation; Departure Functions- draw analogy of some kindSelecting a root of cubic equationEquilibrium Graphical Analysis