Below is a list of potential research projects for students joining the Bredesen Center. Please note these are only a few of the projects available for students admitted to the program. Please feel free to contact any ESE or DSE faculty researcher with questions.Application Info
Dr. Pat Collier
Neuromorphic Circuits Based on Biomimetic Membranes
We are constructing synthetic synapses, soma and axons for brain-like neuromorphic computing (i.e., neural networks) that feature the compositions, structures, and switching mechanisms found in actual biological membranes. State-of-the-art micro- and nanofabrication tools, such as thin-film deposition, lithography and etching, as well as microscale 3D-printing, are used in conjunction with soft materials such as phospholipid bilayers with embedded transmembrane biomolecules like ion channels to configure hybrid bioelectronic circuitry. These neuromorphic circuits can emulate key brain-like computing behaviors such as synaptic plasticity, enabling learning and computing tasks. In addition to memristive circuits based on voltage-activated alamethecin peptides, neuromorphic circuitry can be customized in innumerable ways through the incorporation of other stimuli-responsive biomolecules, such as light-, chemical-, or mechanosensitive transmembrane proteins.
- S. Najem, M.S. Hasan, R.S. Williams, R.J. Weiss, G.S. Rose, G.J. Taylor, S.A. Sarles, C.P. Collier, “Dynamical Nonlinear Memory Capacitance in Biomimetic Membranes”, Nat. Commun. 10, 3239 (2019).
- S. Najem, G.J. Taylor, N. Armendarez, R.J. Weiss, M.S. Hasan, G.S. Rose, C.D. Schuman, A. Belianinov, S.A. Sarles, C.P. Collier, “Assembly and Characterization of Biomolecular Memristors Consisting of Ion Channel-doped Lipid Membranes”, J. Vis. Exp. 145, e58998 (2019).
- S. Najem, G.J. Taylor, R.J. Weiss, M.S. Hasan, G. Rose, C.D. Schuman, A. Belianinov, C.P. Collier, S.A. Sarles, “Memristive Ion Channel-Doped Biomembranes as Synaptic Mimics”, ACS Nano 12, 4702-4711 (2018).
Quantum Chemistry for Energy Sciences
The simulation of nonequilibrium processes in complex energy-relevant systems such as heterogeneous catalysis, crystal growth in geosciences or redox reactions on supercapacitor surfaces demands the inclusion of electronic structure in long timescale reactive molecular dynamics (MD) simulations. The density-functional tight-binding (DFTB) method is an approximate version of density functional theory (DFT) that is three orders of magnitude faster. We achieve a predictive quality of DFTB/MD simulations by using a combination of a) the best possible physics within a TB framework and b) a differential neural network (DNN) for correcting systematic deviations from chemical accuracy. Since the neural network is trained to predict errors of the DFTB method rather than new physics, the DFTB-DNN approach will be able extrapolate energies and forces for structural configurations that were not included in the training sets, unlike conventional NN-based potentials. The project will involve further development and implementation of the DFTB-DNN method itself and/or its application in highly accurate long timescale reactive MD simulations for catalysis, geochemical, and energy sciences.
If you have questions, please contact Dr. Stephan Irle at email@example.com.
I am looking for students interested in quantum sensing and quantum photonics experiments. We have a growing experimental capability for low temperature experiments probing single photon sources, quantum optomechanics, spin qubits, and nanoscale behavior in superconducting qubits and sensors. Preferably with a strong physics background.
Keith Kline and Virginia Dale are looking for a student who is fluent in Spanish to travel with them to Guatemala in July 2019 and help them in a project that is exploring approaches to assess progress toward more sustainable agricultural landscapes. In addition, Keith has work for this student to also be engaged in data mining activities related to land use.
Quantum State Estimation of Entanglement in a Quantum Communications Network in a Nuclear Disturbed Environment
Advancements in communications networks are expected to include capabilities and assets for quantum communications. As such, a thorough understanding of quantum network performance is imperative, particularly under adverse operating conditions. For many quantum applications, and for security applications in particular, performance is directly related to quantum entanglement. ORNL proposes to analyze the viability of quantum communications networks in a nuclear disturbed environment by quantifying the effect of that environment on qubit transmission across optical links and, subsequently, on the underlying quantum entanglement in the network. The analysis will rely on an ORNL-developed quantum state estimation technique that excels in changing environments and allows one to unambiguously evaluate the quality of a quantum network. A five-year effort (three years plus two one-year options) is proposed in which quantum-state estimation techniques will be used to explore the limits of quantum communication in a nuclear disturbed environment. The project will begin with a thorough analysis of a single quantum channel in a nuclear disturbed environment and will build upon that foundation to incorporate increasingly complex quantum networks. The proposed research will establish fundamental bounds on distributed entanglement in a nuclear disturbed environment and will relate those bounds to quantum network security and performance.
2D Quantum Materials and Devices Project
In this PhD project you will reveal new properties of novel 2D quantum materials that are composed of atomically-thin layers by advancing their synthesis and processing, performing state-of-the-art methods for their optical and electronic characterization, and fabricating prototype quantum devices. You will be working within a team comprised of experienced postdocs and staff (as well as other students) in the Functional Hybrid Nanomaterials group at the Center for Nanophase Materials Science involved in each aspect of this process, including the growth, characterization, and application of atomically-thin layers of 2D materials such as graphene, boron-nitride, and transition metal dichalcogenides (TMDs, such as MoS2 , MoSe2, WS2, WSe2, PdSe2, etc.) as well as 2D topological insulators, and semimetals that are emerging quantum materials. You will explore the growth and properties of new 2D materials, learning and interfacing with experts in in situ diagnostics of growth by chemical vapor deposition and pulsed laser deposition, optical and electron spectroscopy characterization techniques, and device physics including nanofabrication techniques. The overarching goal is the development of quantum devices based on various 2D layered materials and heterostructures by exploring and exploiting their emerging quantum properties, which may include new metallic, semiconducting, magnetic, or superconducting quantum phases based on their quantum confinement or topology. You will learn and develop methods for transferring and combining various quantum materials from bottom-up and top-down assembly techniques in order to explore such novel quantum properties of these materials and their heterostructures for quantum information science, focusing on a particular material and emergent property. You will perform advanced synthesis and characterization experiments in the state-of-the-art laboratories at CNMS, work on novel device fabrication in the modern clean room and collaborate with various groups at ORNL on quantum materials and technology.
Interested students should have a background in Electrical engineering, Materials Science, Physics, Chemistry, or related discipline.
Energy and Transportation Sciences Division at ORNL
We intend to look for a good graduate student candidate to work on our nanomaterials (membranes/adsorbents/catalysts) research for renewable energy and environmental applications. The student will become part of our separations team as well as part of the Bioprocessing Separations Consortium program that involves on-going collaborations among multiple national laboratories. The successful candidate will conduct complex research in membrane/adsorbent materials synthesis and separation/purification process development for thermochemical processing of biomass to biofuels and high-value chemicals. Research will include development of advanced materials including ceramic/polymeric/graphene-based membranes that contain tailor-designed nanostructures and chemical functionalities for enhanced water/ion transport, highly selective organic molecule extraction processes, and separation-enhanced catalytic conversion. These future generations of hybrid or composite membranes may include a variety of functionalized nanomaterials such as nanoporous inorganic (ceramic/metallic) supports, polymer or cross-linked graphene coatings, inorganic composites, and mixed matrix materials. The research spans basic to applied research in in bioenergy, transportation, and energy storage programs. The candidate will be expected to work in multi-disciplinary teams. The Bioprocessing Separations Consortium is a highly collaborative interdisciplinary team of chemical engineers, material scientists, physical chemists, electrochemists and biochemical engineers/scientists working toward advance functional materials for separations and catalytic conversions of biomass and derived intermediates; more information can be found at www.bioesep.org. The candidate will be encouraged to collaborate with the consortium team as well as other ORNL postdocs/researchers and actively present results at team meetings and conferences.
Dr. Kao leads the Hydrologic Systems Analysis Team in the Environmental Sciences Division at Oak Ridge National Laboratory. Dr. Kao’s team carries research related to (1) hydro-climate simulation, (2) extreme precipitation and flood modeling, (3) climate change impact assessment, (4) geographic information system applications, and (5) water availability for energy production.
Current projects include:
- Evaluate the effects of climate change on hydropower generation
- Simulation and evaluation of probable maximum precipitation and flood
- Application of point precipitation frequency estimates to watersheds
- Conterminous US (CONUS) hydrologic modeling
- Simulation and validation of extreme flood events using GPU-accelerated high-resolution hydrodynamic models
Dr. Ashfaq research focuses on the development of approaches that can reliably identify the dominant mechanisms governing the climate system response at global, regional and hydrologic-basin scales, quantify the model-based uncertainties associated with those physical processes, and create a foundation of a multi-disciplinary Earth System modeling framework that will enable more comprehensive, rigorous investigation of the challenges posed by climate variability and climate change.
Students will participate in the execution of regional earth system model experiments and in the development of robust analytical and modeling strategies to enable 1) a mechanistic understanding of dynamic and thermodynamic drivers of large-scale mesoscale patterns that are associated with multivariate weather and climate extremes (such as droughts, heat waves, wet extremes) at regional to continental scales, and 2) investigation of the impacts of variations in climate extremes on natural and human systems.
Current research activities include:
- Design and execution of high-resolution regional earth system modeling experiments over the regions of interest and in the development of new methods for the identification of modeling errors.
- Exploration of existing and new methods for the development of analytical metrics to identify atmospheric patterns associated with extremes events and their relationship with local and remote processes.
- Development of a model analysis software for Energy Systems.
- Investigation of the impacts of climate variability and change on natural and human systems
The Loeffler research group explores microbial processes in environmental systems that affect the fate and longevity of contaminants and control carbon and nitrogen cycling and associated greenhouse gas (e.g., nitrous oxide, N2O) emissions. A collaborative project seeks to determine if the abundance and taxonomic diversity of N2O-reducing bacterial species (phylogenetic diversity), as well as the activity of diverse nosZ gene alleles (genetic diversity), can predict the N2O reduction rates and N2O emissions (functional diversity) of representative U.S. terrestrial ecosystems.
Interested students should have a background in microbiology, chemistry and/or
environmental engineering, and a keen interest in advancing fundamental understanding of microbial systems and how they control relevant environmental processes.
Dr. Duty’s research group is investigating new materials that are suitable for 3D printing (additive manufacturing). In contrast to conventional desktop printing of simple thermoplastics, Duty’s group focuses on printing of high temperature reinforced composite materials and novel printing techniques, including Big Area Additive Manufacturing (BAAM) which prints structures on the order of several meter at a rate of 200x faster than conventional techniques. Duty’s research group works closely with ORNL’s Manufacturing Demonstration Facility on projects such as:
- “Printability” Model: A viscoelastic model that maps appropriate processing conditions for printing of high performance polymers and reinforced composites.
- Liquid Nails: A patent-pending approach for 3D Printing that uses “liquid nails” to improve the bond between printed layers, which has traditionally been the weakest link in 3D printed structures.
- Controlling Distortion: As plastic solidifies, it shrinks. For 3D printing, this produces a large amount of distortion, especially for large parts. Duty’s research is working to change the print paths and the local material composition to develop methods for controlling distortion in a printed part.
- High Temperature Tooling: Aerospace and automotive companies use large and complex molds (or “tools”) to define the shape of composite parts, which are formed at high temperatures and pressures in an autoclave. In collaboration with ORNL, Duty’s group is using the high temperature materials they’re developing to print and test these tools for production, cutting the time and money required for making components significantly.
- Fatigue Life: Several applications where 3D printing of metals is attractive are limited by fatigue behavior. Duty’s group has been investigating how different printing conditions affect the microstructure of the material, and how this in turn affects the fatigue life of high performance titanium parts.
This work will focus on soils, geochemistry, and microbial communities. Research topics will be experimental in nature and will be designed to improve the model representation of redox-active microbial functions in tropical wetlands and soils. Expertise or interest in microbial community function, wetland biogeochemistry, greenhouse gas emissions, and redox reactions in subsurface materials is desired. Students will have the flexibility to explore interests in microbial community function, wetland biogeochemistry, greenhouse gas emissions, and redox reactions in subsurface materials.
Students will have the opportunity to interact closely with a team consisting of soil biogeochemists, modelers, and a bioinformaticist to investigate relations between geochemical and microbiological features of wetland soils and greenhouse gas releases. The research will involve lab- and field-scale measurements of greenhouse gas emissions, microbial metagenomics, and soil geochemistry. Students are expected to work closely with modelers who will utilize experimental data and observations to improve and develop microbial models. Research will involve literature review and data analysis. Participation in scientific conferences and publication of results is expected.
Qualities essential for this position are:
- A real passion for understanding the natural world
- The ability to communicate clearly and effectively, in oral and written forms
- Competence in statistical techniques
- Self-motivation and goal setting skills
- Ability to work in a collaborative environment
- BS or MS in Environmental Science, Biogeochemistry, Microbiology, Soil Science, or a related discipline
Dr. Pint leads the Corrosion Science and Technology Group in the Materials Science and Technology Division at Oak Ridge National Laboratory. The group covers all forms of corrosion for power generation and transportation but specializes in high temperature issues.
Current projects include:
- Molten salt compatibility for concentrated solar power thermal storage and working fluid for nuclear energy. Critical issues remain to be addressed to define economical operating windows for this technology.
- Supercritical carbon dioxide compatibility is of interest for concentrated solar power, fossil energy and nuclear energy. This technology offers much higher efficiencies but compatibility with affordable structural alloys is needed to lower the cost.
- Development of Integrated Computational Materials Engineering (ICME) models for high temperature oxidation performance. This is a critical missing link in the development of the next generation of high temperature materials for transportation and power generation.
- Lifetime performance models are needed in a variety of areas including thin-walled heat exchangers. National laboratories are able to generate longer-term data sets than universities but the key next step is to harness this information into a predictive model for the design of next generation systems for transportation and power generation.
Dr. Arash Shaban-Nejad’s lab in the UTHSC-Oak Ridge National Lab (ORNL) Center for Biomedical Informatics at the University of Tennessee Health Science Center offers multiple research assistantship positions to work on projects in medical and public health informatics, epidemiologic surveillance, precision medicine and big-data analytics in healthcare.
Students will find opportunities to tackle real world computational challenges in public health and medicine through the use of tools and techniques from artificial intelligence, natural language processing, machine learning, social media analytics, knowledge representation, and semantic web.
Dr. Zili Wu
The research project (taking place at CNMS of ORNL) will be focused on converting small molecules such as water, CO2, and N2 into useful chemicals and fuels such as H2, alcohols and NH3 with the help of low dimensional photocatalysts/photoelectrocatalysts. Desired student may have research background or interest in the area of energy conversion, heterogeneous catalysis, photocatalysis, electrocatalysis, physical chemistry and material chemistry. Interest in in situ/operando spectroscopy characterization of catalysts and surface chemistry is also welcome.
If you have questions, please contact Dr. Zili Wu at firstname.lastname@example.org.