Events at ORNL

Sparse Sampling Methods for Image Processing and Data Analysis

This talk will focus on sparse sampling methods and fast optimization developed specifically for image processing and data analysis. Sparse sampling has the ability to provide accurate reconstructions of data and images when only partial information is available for measurement. Sparse sampling methods have demonstrated to be robust to measurement error. These methods have the potential to scale to large computational machines and analysis large volumes of data.

Presenter

  • Rick Archibald, Computational and Applied Mathematics Group

Can DRAM Do More than Just Store Data?

In today's systems, DRAM is used only as a storage device. Off-chip DRAM interfaces allow the memory controller to read and write data. As a result, any operation must first read the required data from DRAM and store the results back into DRAM. In this line of work, we observe that this model is very inefficient for certain key primitives in modern systems. And we ask the question, "Can DRAM do more than just store data?" 

Presenter

  • Vivek Seshadri, Carnegie Mellon University, Pittsburgh

Center for Radiation Protection Knowledge: Mission and Ongoing Activities

The Center for Radiation Protection Knowledge (CRPK, http://crpk.ornl.gov/ ) was established within the Environmental Sciences Division at Oak Ridge National Laboratory (ORNL) as part of a memorandum of understanding (MOU) between ORNL and five federal agencies in 2010. The MOU renewal is currently being signed by six federal agencies.

Presenter

  • Nolan Hertel, Georgia Institute of Technology and ORNL Joint Faculty Appointment, Atlanta, Georgia

Nuclear Fuel Cycle Assessment: Identification of Issues and Challenges for Decision Makers

The Fuel Cycle Options Campaign in the United States involved an evaluation and screening (E&S) study of future fuel cycle options. More than 4,000 fuel cycle options were categorized into 40 groups based on characteristics such as the number of reactor stages, reprocessing strategy, primary natural resource, etc. RNSD has been leading the assessment of a range of reactor and fuel cycle options at equilibrium and during transition from the current to future promising options.

Presenter

  • Andrew Worrall and Jeff Powers, Division Staff

Partitioned Domain Model Error Estimation and Adaptivity

There is a general trend in computational mechanics toward more complex mathematical models in order to incorporate a large set of  phenomena and to capture complex behavior. In many cases, the full complexity of the model is not required throughout the entirety of the domain but only in a small subset. This motivates domain partitioning methods, where the full model is used only on a subset "A" of the problem domain "O" and approximated by a coarse model on subset "B".

Presenter

  • Timo van Opstal, Norwegian University of Science and Technology, Trondheim

Neutrons and Materials for Energy Storage

Sensitivity to light elements in the presence of heavier elements makes neutron diffraction an ideal tool to study oxides, hydrides, and compounds containing Li. As a result neutron crystallography has been very successfully used to elucidate structures of electrode and electrolyte materials used in both Li-ion batteries and solid oxide fuel cell materials. In this presentation, I will speak about several of these systems where structure helped understand the electrochemical properties.

Presenter

  • Ashfia Huq, Chemical and Engineering Materials Division

Interface Structure and Its Controlling of Helium Concentration

Interface Structure and Its Controlling of Helium Concentration: Controlling radiation-induced defects through interface engineering is shown to be an efficient way in mitigating the radiation damage by introducing stable sinks at which defects preferentially recombine and annihilate. One approach to achieve this microstructure is through the synthesis of nanolayered metallic materials using physical vapor deposition.

Presenter

  • Qiangmin Wei, Micron Technology Inc., Boise, idaho

“MXenes,” Two-Dimensional Early Transition Metal Carbides and Carbonitrides: Synthesis, Properties and Applications

Ternary layered carbides and nitrides with formula of Mn+1AXn (M stands for early transition metal, A for group A element, X is carbon or nitrogen, and n=1, 2, or 3), so called MAX phases, are known for their unique combinations properties of ceramics and metals. It was found recently that etching atomically thin layers of aluminum from the MAX phases results in forming weakly bonded stacks of two-dimensional (2D) layers of early transition, coined as MXenes. The etching was carried out in fluoride contained aqueous systems.

Presenter

  • Michael Naguib Abdelmalak, Physical Sciences Directorate

The Effect of High Pressure and Disorder on Negative Thermal Expansion Materials Examined by Powder Diffraction

Many features that are often associated with negative thermal expansion (NTE), such as low density, a flexible framework, and the existence of phonons that soften on compression (leading to negative mode Gruneisen parameters), also lead to rich and complex behavior when stressed. The occurrence of crystal-to-crystal and/or crystal-to-glass phase transitions at modest pressures is common. Stresses capable of inducing these transitions can often be realized in composites containing NTE materials, due to thermal expansion mismatch.

Presenter

  • Angus P. Wilkinson, The Georgia Institute of Technology, Atlanta

LSMS and WL-LSMS: Codes for First Principles Calculation of the Ground State and Statistical Physics of Materials

The Locally Self-consistent Multiple Scattering (LSMS) code solves the first principles Density Functional theory Kohn-Sham equation for a wide range of materials with a special focus on metals, alloys and metallic nanostructures. It has traditionally exhibited near perfect scalability on massively parallel high performance computer architectures. We present our efforts to exploit GPUs to accelerate the LSMS code to enable first principles calculations of O(100,000) atoms and statistical physics sampling of finite temperature properties.

Presenter

  • Markus Eisenbach, Scientific Computing Group