Outline. Scientific Method of Research. Group Meeting Presentation 1/23/2004 Prof. T. Dobbins. Scientific Research Method Development of Mathematical Models Applying these methods to completing an MS Thesis or a Ph.D. Thesis.
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Outline Scientific Method of Research Group Meeting Presentation 1/23/2004 Prof. T. Dobbins • Scientific Research Method • Development of Mathematical Models • Applying these methods to completing an MS Thesis or a Ph.D. Thesis Scientific Research – 1: investigation or experimentation aimed at the discovery and interpretation of facts, revision of accepted theories or laws in the light of new facts, or practical application of such new or revised theories or laws2: the collecting of information about a particular subject
Scientific Method of ResearchFour Steps: • If the experiments prove the hypothesis to be true, it becomes a theory or law of nature. If the experiments prove the hypothesis to be false, the hypothesis must be rejected or modified. The scientific method used properly should give us predictivepower (to understand phenomena which have not been tested). Further reading found at http://teacher.nsrl.rochester.edu/phy_labs/AppendixE/AppendixE.html
Observation – an act of recognizing and noting a fact or occurrence often involving measurement with instruments • Experiments performed in the laboratory. • Experiments gained from knowledge of the literature. Keys to Implementation in your Research: Sorting Observations (from Literature Searches): Formulate Hypothesis! Note Results (in report format- optional) for future use in confirming/denying your hypothesis (once your hypothesis is found)!
Hypothesis – tentative assumption made in order to draw out and test its logical or empirical consequences Example, • Hypothesis of author Anton (UTRC paper) : Ionic radius of Ti4+ enhances desorption kinetics. • Observation in Paper by Anton et al.: NaAlH4 doped with Ti4+, Ti3+ and Ti2+ have different ionic radii, but the same rate of enhanced H2 desorption kinetics. • New Hypothesis in Paper by Anton (not tested by Anton, et al.): Ti2+, Ti3+ and Ti4+ adopt the same oxidation state after entering the NaAlH4 structure. • Keys to Implementation in your Research: • Good Hypothesis can be TESTED with Experiment or Calculation. • This requires A LOT of thought and reading--- leap from observation to hypothesis. It is worth the effort because after thinking this through, you are ready to go into the laboratory (which is the FUN part of research)!
Experimental Testing – to be assigned a standing or evaluation on the basis of tests 2: to apply a test as a means of analysis or diagnosis Example, • New Hypothesis: Ti2+, Ti3+ and Ti4+ adopt the same oxidation state after entering the NaAlH4 structure. • Test: EXAFS Absorption spectroscopy can measure bond length and # of bonds. We may dope NaAlH4 with Ti2+, Ti3+ and Ti4+ and measure bond length of each. If they are the same, then they have all assumed one oxidation state after entering the structure (and we can measure this oxidation state also using EXAFS by determining the # of bonds). • Keys to Implementation in your Research: • Good TESTS will prove or disprove your hypothesis. • Experimental Tests can be performed within the realm of computing. (e.g. Coventor model with calculations and predictions can serve as experiment and model). • Consider all alternatives. Experiment may not disprove all (but may disprove only parts) of your hypothesis. That is still alright to perform. Carefully note which aspects of your hypothesis this experiment will test. • Consider the availability of instrumentation to perform your tests.
Predictions– to declare or indicate in advance; especially: foretell on the basis of observation, experience, or scientific reason Example, Test: EXAFS Absorption spectroscopy can measure bond length and # of bonds. We may dope NaAlH4 with Ti2+, Ti3+ and Ti4+ and measure bond length of each. If they are the same, then they have all assumed one oxidation state after entering the structure (and we can measure this oxidation state also using EXAFS by determining the # of bonds). Prediction 1: If Ti2+, Ti3+ and Ti4+ gain equivalent oxidation states after entering the structure, then the same should be true for Co2+, Co3+, and Co4+ (or any other metal dopant). or Prediction 2: If Ti2+, Ti3+ and Ti4+ gain equivalent oxidation states after entering the structure via ball-milling, then the same should be true for Ti2+, Ti3+, and Ti4+ after entering the structure via chemical precipitation from Na+, Al3+, and Ti?+ salt solutions. • Keys to Implementation in your Research: • Good Predictions can also be tested against your hypothesis. • Consider going back to the basics (textbook theory) to development of a mathematical model/construct which will help to make predictions about more systems than you can reasonably test.
Mathematical Models– Empirical vs. Deterministic Examples, Test: EXAFS Absorption spectroscopy data is in hand. Prediction 1: If Ti2+, Ti3+ and Ti4+ gain equivalent oxidation states after entering the structure, then the same should be true for Co2+, Co3+, and Co4+ (or any other metal dopant). Model: We use FEFF8.0, WINXAFS to fit the XAFS equation to measured data --- varying types of neighboring species (e.g. neighbors may be 2 Na atoms and 1 Al atom or 3 Al atoms and 1 Na atom). bond length and # of bonds (coordination number) until we have a good fit. We did not know what environment our Ti atom was in prior to model fitting, now, we have modeled our system to match our data. Our model is then made up of the XAFS equation, bond lengths, and # of bonds. • Keys to Implementation in your Research: • All thesis experiments should have empirical models (at least). • If do not have a mathematical model--- only data, then we need to find an equation for which we can perform least squares fitting your data. • My suggestion: If you run into an interesting hypothesis which can be tested via deterministic models (first principles approach), meet with IfM modeling faculty (Mainerdi, Paun, Hegab or DeRosa) to discuss the hypothesis and modeling.
Further Suggestion: • Know what has been done by others. Do not reinvent the wheel unnecessarily!!! • Understand your field. This qualifies you to make reasonable hypothesis about fundamental advances in the field. • Do not strive to solve all problems in the field, look for small advances in your field. • Small advancements lead to critical developments. • Prepare to report results even if hypothesis fails. False hypothesis are also advancements in science (and will save others time and money on repeating these experiments). Failed hypothesis should also be used to make suggestions for future directions (making you and EXPERT since you can suggest new directions in your field!!!).
What do I need to do to Complete a Thesis Option??? • Perform 1 iteration of the Scientific Method!!! • Observation • Hypothesis • Experimental Test • Prediction --- then you may STOP (You do not need to test predictions in order to successfully write your thesis). Your thesis should, however, include a reporting of your predictions under the heading…’ Suggestions for Future Work’. If you complete one iteration within 5 weeks, then you should go further…. • Ph.D. Thesis should have publishable results from iterations of the Scientific Method!!! Good Luck and Happy Researching!!!