“Minimum Requirements for a PhD thesis at MSE”

Summary of Deliberations of PhD Committee, January to July 2010.

Committee members:

Wang Junling, Zhang Hua, Lam Yeng Ming, Wong Chee Cheong, Ali Miserez, Subbu Venkatraman

The main goals of the PhD Committee were as follows:

1. To define what constitutes an acceptable thesis in MSE 2. To define minimum requirements of a graduating PhD student

As a result of deliberations, the Committee recommends the following.

1. Thesis structure/content should essentially follow what is termed the PEL model:

Based on this model, a thesis is expected to have the following ingredients:

1. Literature review

2.

which covers the relevant background for the proposed thesis objectives; the main purpose of this review is to substantiate the novelty of the thesis work. Aims/Scope/Hypothesis

: This section should address the overall objectives of the thesis work, and define its scope (what is being attempted, what is not). In addition, there should be the statement of a “working hypothesis” that guides the work. Examples of presuppositions/hypotheses include:

ExampleA new metal/ceramic composite is to be fabricated with superior properties than currently existing. Ceramic particles are used as reinforcement phase.

1

Hypothesis: The composite can be made tougher by optimizing the size of the reinforcement and the strength of the interface. In particular, the hypothesis is that large reinforcement are more prone to cracking, while smaller one generate larger internal stresses during processing. Hence an optimized particle size exists. Experiments: Composites are made with various sizes of particles and their toughness measured. If the composite indeed has an optimum particle size for toughness maximization, the initial hypothesis is valid. A refined model can now be constructed to explain the data in a more quantitative way. If the initial hypothesis turned out to be non-valid, alternate mechanism are developed. New experiments might be needed to validate them. (Other examples in the Appendix)

3. A section that details the experimental (or computational) methods employed and the materials used

4. The heart of the thesis is the

, is essential. It is possible to have separate Methods/materials sections where appropriate. For example, if the results are divided into separate chapters (synthesis/characterization/performance) then it may be appropriate to have a separate Materials/methods section for each chapter.

Results and Discussion

5. A

section. This section should present the results clearly and in logical fashion, followed by inferences and discussion. Particular attention must be paid here to novelty and to critical evaluation/analysis of the results. The results must be explained and understood; mechanisms are typically expected here, along with supporting evidence.

Conclusions

6. A

section, which succinctly captures the novel findings along with an explanation of the findings. This section should not be a list of all the data obtained, but as the title suggests, concentrate on the most important conclusions drawn from the data.

Future Work

section is optional, but recommended. This should focus on what the gaps are in the current work, and how those could be addressed.

Introduction - Background - Literature review to focus on thesis topic; main idea is to use it to show novelty of work only

Aims-Motivation - scope - hypothesis

Methods/ Materials

Results/ Discussion: the heart of the thesis

Conclusions: relate back to hypothesis

CHECKLIST (for TAC):

o Does the thesis contain at least one Original Contribution to the field ? o Sufficient Scientific content? Does it have mechanistic explanations for the

observations? Has the mechanism been verified? o First authorship in at least one journal paper in MSE list o Does the student have a good grasp of future topics worth working on?

(additional check points meant for the student) o “Do I consider myself a true expert of my thesis project” ? o “Have I thoroughly read and digested the literature related to my project, including

recent publications (last 5 or 10 years) in direct relation to my work” ? o Do I understand the basic principles of operation of the instruments used in obtaining

important data for the thesis?

APPENDIX Thesis examples:

Self-assembly mechanisms of structural proteins in a hard tissue Example 2

Hypothesis: A given biological tissue is made of proteins that self-assemble into a 3-Dimensional network. Evidences suggest that there are no covalent interactions between the individual macromolecules. An hypothesis is that other types of interactions govern the self-assembly process. It is further speculated that these are one or a combination of the following: (1) hydrogen bonding interactions, (2) hydrophobic interactions, (3) electrostatic interactions Experiments: Proteins are extracted from the native tissue and “re-constituted” on a substrate, with the goal to replicate the self-assembly process. Various conditions are tested, with testing variables chosen so as to promote/inhibit interactions of the hypotheses (for instance aqueous buffers of various pH, as well as buffers of various ionic strength). Observations of the resulting structures by surface probe microscopy techniques allows to identify conditions that govern self-assembly mechanisms and to verify which of the initial hypotheses is valid.

Example 3 Development of novel single phase multiferroic materials Hypothesis: Perovskite oxides with the chemical formula of ABO3 posses a wide spectrum of useful properties, including ferroelectricity, ferromagnetism, superconductivity and high dielectric constant. Intensive research has been devoted to this group of materials. It is understood that Pb and Bi ions on the A site leads to ionic displacement that is responsible for ferroelectricity, while magnetic ions, e.g. Fe, Co and Mn, on the B site generates magnetic response. It is thus believed that by combining Pb or Bi on the A site and magnetic ions on the B site, we may be able to obtain a material that possesses both ferroelectric and magnetic properties. Experiments: We propose to start with PbTiO3, a typical ferroelectric material, and gradually replace some of the Ti ions with magnetic ions (Fe and Co) to produce a new multiferroic material. Such multiferroic oxides offer the possibility of controlling magnetism with electric field because of the cross coupling between the magnetic and electrical orders, and they can be used for multi-states memory and spintronic devices.

Nanoparticles approaching each other under interactive electrostatic forces will arrange themselves (self-assemble) into symmetrical objects but the crystallization process has never been described. Probing into the dynamics of this process would help in modeling the crystallization path.

Example 4

Hypothesis: Nanoparticles arranged into particular symmetries will display diffraction properties with suitable wavelengths of light. Thus analyzing the in-situ diffraction patterns of a crystallizing colloidal crystal will reveal its internal organization dynamics. Experiments: Build a broadband spectrometer which can focus its probe beam onto a sessile drop whose edge is the colloidal crystal. Then collect diffraction spectra as a function of time and all other relevant chemical properties of the colloid. Diffraction data translated into structural data will give a frame by frame picture of the genesis of self-organization.

Example 5

Study of the growth mechanism of CNTs for further controlling the CNT growth, and to meet the needs of particular requirements of CNT arrays in the wide range of basic studies and advanced applications. Hypothesis: There are two growth mechanisms for CTNs. One is “tip growth” and the other is “base growth”. “Tip growth” means the catalyst is in the top of CNT during the CNT grows. “Base growth” means the catalyst is in the root of CNT during its growth. Since the mechanism is related to the experimental condition, in our designed experiment, by using SEM and AFM, we can confirm the growth mechanism. Experiments: By using DPN, the catalyst patterns can be easily generated on solid substrates. After the samples are put in a CVD system, in a certain experimental condition, CNTs will grow on the patterned catalyst area. By using SEM and AFM, we can easily observe the grown CNTs. If we observe the root area and tip area of CNTs, we can observe where the catalyst particles are. Then we can confirm the growth mechanism of CNTs.