09/23/2008
Optimal dynamic operation of chemical processes: assessment of the last 20 years and current research opportunities by Jim Rawlings, Department of Chemical and Biological Engineering, University of Wisconsin-Madison

Abstract: This talk, intended for the general chemical engineering audience, provides a critical assessment of the research progress in the fields of dynamic operation of chemical processes and process control. The following points are discussed:

• What new intellectual ideas, concepts, and tools have emerged from this research field during the last 20 years.
• How successfully have the research innovations in problem conceptualization, formulation, and solution been reduced to industrial practice.
• What application areas have benefited from this research.

Next we present a selection of open problems and research challenges. These research challenges are formulated by enumerating the current industrial needs in different application areas, and identifying common themes that can be addressed by developing new tools in systems theory and engineering. We focus on two topics of interest to our research group:

• How do we distribute tasks in a large-scale application to a collection of agents/controllers so that the overall system achieves near optimal operation.
• How do we use systems and control tools to address the larger goal of optimizing process economic performance rather than traditional lower level tasks such as set point tracking and disturbance rejection.

09/25/2008
IN SITU HREM OF MATERIAL REACTIONS by Robert Sinclair, Department of Materials Science and Engineering, Stanford University

Abstract: The reactions which occur at material interfaces and in thin films have a profound effect on the resulting structure and properties. One effective method to investigate such behavior is to follow its progress, in real time, using high-resolution imaging in a transmission electron microscope. This provides direct viewing, at the atomic level, and allows kinetic measurements by changing the sample temperature in a controlled fashion. The focused-ion beam machine (FIB) further extends this capability. The development of these methods, particularly for materials of interest for semiconductor devices, will be described, and their importance emphasized using an historical analogy.

11/20/2008
FUNCTIONAL DESIGN FOR NANOSCALE ARCHITECTURES by Dr. Marilyn L. Minus, School of Polymer, Textile and Fiber Engineering, Georgia Institute of Technology

Abstract: Functional materials are indigenous to nature. From a morphological standpoint, these materials are designed such that every feature is involved in its functional capability. Materials produced in the research lab and industries have yet to capture the kind of functional efficiency exhibited in nature. The field of nanotechnology has ushered in a new era for the design and processing of materials. The abundance of nanomaterials available provides endless combinations for imagining and constructing nanocomposites which have applications within one or more field of study. In addition, this field has also opened new opportunities of educational gleaning for future generations of scientist. The nano- and macro-scale properties of polymers have long been studied and much is already known. However, the mishmash of polymer with nanoparticles has now broadened our view of how these macromolecules can be influenced into novel architectures at the nanoscale to produce new structures and enhancement of bulk properties. Polymer selforganization/assembly directly influenced by nanoparticles provides a basis to approach many fundamental research questions including the design of new materials for energy applications. Understanding these processes and utilizing these designs has the potential to reshape our view of how to incorporate polymers into nanocomposites to tailor bulk applications for specific functionalities. Such intelligent design combines both top-down and bottom-up approaches for erecting nanocomposites. In our world, new product design, development, and optimization are in constant demand and these materials find their beginnings in the laboratory. The potential implications of applying technology to the nano world breathe new life into researching materials for energy applications. Can we dream of a way to use the wealth of new materials available today to construct a system that will simultaneously convert CO2 to O2 and provide energy from solar and bio sources? Such a mechanism can exist as thin flexible sheets can be incorporated into window panels, construction and automotive materials, or industrial textiles making use of rain water and sunlight to provide electrical energy to buildings or vehicles while cleaning the air we breathe.

10/23/2008
Efficient Ensemble-Based Closed-Loop Production Optimization by Professor Dean Oliver, Mewbourne School of Petroleum and Geological Engineering, University of Oklahomct

Abstract: With the advances in smart well technology, substantially higher oil recovery can be achieved by intelligently designing the operation scheme in a closed-loop optimization framework. The closed-loop optimization consists of two parts: geological model updating and production optimization. Both of these parts require gradient information to minimize or maximize an objective function: squared data mismatch or the net present value (or other quantities depending on different financial goals), respectively. Alternatively, an ensemble-based method can acquire the gradient information through the correlations provided by the ensemble. Computation in this way is nearly independent of the number of control variables, reservoir simulator and simulation solver. We propose a new method for closed-loop optimization, which combines an ensemble based optimization scheme (EnOpt) with the ensemble Kalman filter (EnKF). The EnKF adjusts the reservoir models to honor observations and propagates the uncertainty in time. EnOpt optimizes the expectation of the net present value based on the updated reservoir models. The combined method is robust, completely adjoint-free and can be readily used with any reservoir simulator. The proposed scheme is illustrated with the Brugge Field test example developed for the SPE-ATW on Closed-Loop Optimization. This test problem has 10 injectors, 20 producers and 3 completion intervals per well that can be controlled independently.

01/22/2009
Unlocking Heavy Oil and Unconventional Resources with Heat by Professor Anthony Kovscek, Department of Energy Resources Engineering, Stanford University

02/26/2009
Objective molecular dynamics by Richard James, Department of Aerospace Engineering and Mechanics, University of Minnesota

Abstract: Perhaps the most important deformations in elasticity are those that represent the bending, twisting and extension of beams. The most important flows in fluid mechanics are viscometric flows. In both cases these are the motions that, when compared with the corresponding experiments, are used to measure the material constants. We give a universal (i.e., independent of the material) molecular level interpretation of these motions. From this viewpoint the bending and twisting of beams and the viscometric flows of fluids are parts of the same subject: in both cases these motions are associated at molecular level with a time-dependent invariant manifold of the equations of molecular dynamics. The presence of this manifold can be used to simplify molecular-level computations. Its presence also suggests a modification of the laws of macroscopic physics. Interesting links to theories of turbulence, to the Boltzmann equation, to the dynamics of nanostructures, and to the Langevin equation will be discussed.

03/30/2009
Protein Misfolding Diseases – Chemical, Mechanical, Structural and Biomimetics Perspective by Professor Ratnesh Lal, Director, Center for Nanomedicine and Professor of Biophysical Sciences and Medicine, University of Chicago

Abstract: Native protein structures are determined by their primary sequences. Protein misfolding can lead normally folded soluble oligomers to form insoluble amyloid fibrils. In vivo, insoluble amyloid fibrils are linked to protein misfolding diseases, including Alzheimer’s Disease (AD), Amyotrophic lateral sclerosis (ALS), prion-diseases, type-II diabetes and systemic amyloidosis. The mechanism of amyloid toxicity is poorly understood. Amyloid β peptide associated with Alzheimer’s Disease forms a U-shaped ‘β-strand-turn-β-strand’ structure. Computational modeling based on protein folding energetics and mechanical mobility predicts these amyloids to form ion channels. Mutlimodal and mutlidimentional atomic force microscopy (AFM) study provides a new paradigm for amyloid diseases – they belong to channelopathies and provide new avenues for designing therapeutics. This presentation will illustrate new advances in our understanding of amyloid diseases and will provide glimpse of biomimetics, bioMEMS, and other possible engineering approaches for effective diagnostics and therapy. Multiscale biomechanics covering nanoscale dissection, mechanics, rheology, cell micromechanics will also be discussed, in particular, using atomic force microscopy to study biological systems from single macromolecules to cell membrane to cells and tissue. We have obtained information about both their structures and their physiochemical properties with direct relevance to cell and tissue physiology, tissue mechanics, tissue remodeling, and biomimetics.

04/23/2009
How Viruses Make New Viruses: A Single Molecule View, by Professor Robert Phillips, Departments of Applied Physics and Mechanical Engineering, Caltech

Abstract: Viruses have enormously rich and varied life cycles. Bacterial viruses have a hallowed position in the development of modern biology and recently have become the subject of intensive physical investigation. Using single-molecule techniques, it has become possible to examine viruses both while they package and eject their DNA. One of the intriguing aspects of these processes is that they bring large forces (greater than 50 pN) into play. My talk will give a general introduction to viruses and their life cycles and will then focus on simple physical arguments about the forces that attend viral DNA packaging and ejection, predictions about the ejection process and single-molecule measurements of ejection itself.

04/17/2008
Physics at the Nanoscale: Tubes, Sheets, Ribbons and Junctions by Professor Steve Louie, University of California, Berkeley

Abstract: The restricted geometry of nanostructures often gives rise to novel, unexpected properties and phenomena. In particular, symmetry and many-electron effects can become significantly more important in determining the behaviors of these systems. In this talk, I discuss some recent progress on using theory and computation to understand and predict some of their electronic, transport, optical, and mechanical properties. Examples of systems of interest include carbon and BN nanotubes, graphene, graphene nanoribbons, and molecular junctions. These nanostructures exhibit a number of unexpected behaviors – novel conductance characteristics, extraordinarily large excitonic effects (even in the metallic systems), interesting friction forces, anomalous anisotropy in the dynamics of carriers (the 2D massless Dirac fermions) in graphene under an external periodic potential, and an electric field-induced half-metallic state for the zigzag graphene nanoribbons, among others. The physical mechanisms behind these unusual behaviors are examined.

03/27/2008
Translocon-Assisted Folding of Membrane Proteins: New insights into Lipid-Protein Interactions, by Steve White, Department of Physiology and Biophysics, University of California, Irvine

Abstract: Recent studies of the translocon-assisted folding of membrane proteins have revealed two unexpected findings about the insertion of transmembrane helices across the endoplasmic reticulum membrane. First, the so-called S4 voltage-sensor helix of potassium channels, comprised of hydrophobic residues and four arginine residues, can be inserted. Second, polyleucine helices as short as 10 residues are readily inserted. Exploration of these observations using physical studies of synthetic peptides in model membranes and molecular dynamics simulations provide new insights into lipid-protein interactions. They reveal that the lipid bilayer is far more complex—and interesting—than its usual lollypop cartoon suggests. The biological, physical, and molecular dynamics data to be presented demonstrate the extreme adaptability of phospholipids that arises from the privileged relationship between their phosphate groups and lysine and arginine residues. This adaptability makes possible the transmembrane insertion of very short helices and the independent stability of potassium channel voltage-sensor domains in membranes. [Research supported by the National Institute of General Medical Sciences and the National Center for Research Resources].

10/25/2007
The Ubiquitous Dipole: A New Paradigm for Solar Energy Conversion, by Anupam Madhukar, Mork Family Department of Chemical Engineering and Materials Science, University of Southern California

Abstract: "Let there be light",Was said first,But, said an excited Miss Dipole,"If I have a sister,We can keep it dark together,And create charge, at last". The quantum mechanics and economics of the conversion of solar light to energy in naturally occurring entities (plants and organisms) or man-made solar cells do not as yet provide efficient and affordable power. In this talk I shall provide an exposition of the fundamental light-induced processes in biotic and abiotic matter, approaches to current photovoltaic solar cells, and discuss a new physical mechanism which may provide a viable means.

09/27/2007
Dynamical Order and Complexity in Rhythmic Chemical Systems, by Professor John L. Hudson, Chemical Engineering, University of Virginia

Abstract: The interaction and synchronization of populations of rhythmic processes is important in a variety of fields ranging including chemistry (influence on overall rate of reaction), biology (circadian rhythm of suprachiasmatic nuclei, essential tremors), and engineering (lasers and microwave systems). A feature of such systems is that the overall, or collective, behavior can be significantly different from the dynamics of the individual components. We introduce the subject of complexity and order with a brief discussion of two examples: the sudden transition to pitting corrosion through the cooperative behavior of metastable pits and patterns of synchrony associated with epileptic seizures.The focus of the presentation is then on experiments with arrays of electrochemical oscillators. The experiments serve as a platform with which the effects of coupling, external forcing, and feedback can be studied since rates of reaction on each electrode can be obtained and elements of the array are individually addressable. Even very weak coupling among sites can produce significant changes in the collective behavior of the system including a phase transition at a critical coupling point at which the onset of synchronization occurs. We show that mutual entrainment in interacting oscillators can be characterized using phase models developed from direct experiments with a single oscillator and sets of oscillators. We show how such phase models can be used to describe and tune complex dynamic structures to desired states; weak, non-destructive signals are employed to alter interactions among nonlinear rhythmic elements. Application is made to the generation of sequentially-visited dynamic cluster patterns similar to reproducible sequences seen in biological systems and to the design of a nonlinear anti-pacemaker for the destruction of pathological synchronization of a population of interacting oscillators.