09/23/2010: Nanoscale Organic Hybrid Materials (NOHMs), by Lynden A. Archer, Cornell University
The effect of suspended particles on transport properties of liquids has been the subject of intense scientific inquiry since Einstein’s seminal works. Historically, suspensions have played an important role in revealing thermal motion of molecules in fluids, in understanding colloidal forces and hydrodynamics of particles in liquids, and most recently, for studying slow dynamics and ageing of glasses. In this talk I will discuss a class of self-suspended nanoparticle fluids recently discovered at Cornell. Termed nanoscale organic hybrid materials (NOHMs), these particle-laden fluids manifest unusual transport properties and offer multiple synthetic handles through which liquid-state physical properties can be facilely manipulated. The talk will focus on transport properties of NOHMs and their applications in electrodes and as electrolytes for next-generation secondary lithium batteries.
10/28/2010: Synthesis and Integration of Multifunctional Oxide Materials, by Professor Jane P. Chang, Department of Chemical and Biomolecular Engineering, University of California, Los Angeles
The demand of engineering metal oxide thin films at an atomic level has grown immensely due to their versatile applications in numerous technologically advanced fields including microelectronics, optoelectronics, photonics, spintronics, energy storage devices and sensors. In this talk, I will discuss current research advances in atomic layer deposition for synthesizing multicomponent and multifunction metal oxides with tailored electronic, chemical, interfacial, thermal properties and microstructures. Specifically, I will highlight our most recent research on the engineering of oxide thin films and their patterning, for their applications in high speed electronics, optoelectronics and energy storage devices.
01/27/2011: High Performance Oxide Conductors and Semiconductors, by Professor Thomas O. Mason, Department of Materials Science and Engineering, Northwestern University
Highly conductive ceramics (e.g., superconductors, semi-metallic oxides, ionic conductors) are well known, as are highly resistive ceramics (e.g., dielectrics, insulators, ferroelectrics). Since the advent of oxide-based chemical sensors (e.g., SnO2-based) and voltage-dependent resistors or “varistors” (e.g., ZnO-based) circa 1970, there has been a steady rise of interest in oxide semiconductors. The renaissance of oxide semiconductors over the past two decades has been particularly dramatic. For example, publications dealing with ZnO have doubled each half-decade since 1990 to more than 25,000 papers (2006-2010). This talk will focus on “medium band gap” (~3 eV) post-transition metal oxides, the basis set of which include CdO, ZnO, In2O3, and SnO2. (Ga2O3 is also of interest, although its band gap is significantly larger.) These compounds and their numerous binary, ternary and multinary compounds and solid solutions are known for their rare combination of high electronic conductivity (when degenerately doped) and optical transparency, and are collectively referred to as transparent conducting oxides or TCOs. TCOs find application as transparent electrodes in display technologies and photovoltaics. When non-degenerately doped, many of the same compounds/solid solutions can serve as thermoelectric oxides or TEOs for direct conversion of heat (solar, commercial, vehicular) to electricity. When very lightly doped, these same materials are excellent “transparent oxide semiconductor” (TOS) candidates for channel materials in oxide-based transparent thin film transistors (TTFTs), especially in the amorphous state (so-called “amorphous oxide semiconductors”). These can be deposited at low temperatures on flexible (polymer) substrates, thereby enabling oxide-based “transparent” and “flexible electronics.” This talk “dusts off” two long-standing (but under-utilized) semiconductor analysis procedures—so-called “Jonker” and “Ioffe” analyses—and applies them to the characterization/optimization of high-performance oxides for advanced applications in display, information technology, and energy conversion technologies.
02/24/2011: Encapsulation of Drug Nanoparticles in Self-Assembled Macromolecular Nanoshells, by Professor Michael V. Pishko, Texas A&M University
A layer-by-layer (LbL) self-assembly technique was used to encapsulate core charged drug particles in a polymeric nanoshell. This approach provides a new strategy in the development of polymeric vehicles for controlled release and targeting to diseased tissues and cells. A nanoshell composed of two biopolymers, poly-L-lysine and heparin sulfate, were assembled stepwise onto core charged drug nanoparticles. The exterior surface of the nanoshell was functionalized with biocompatible polymers(poly(ethylene glycol)) and targeting functional moieties, such as folic acid or protein ligands. Drug nanoparticles of dexamethasone, paclitaxol, and 5-fluorouracil were fabricated using a modified solvent evaporation technique, producing particles within a range of 150 to 300 nm. Assembly of the nanoshell was characterized by zeta potential measurements and XPS. Surface morphology of the encapsulated drug nanoparticles were viewed by TEM and SEM. XPS data collected for PEG modified drug nanoparticles confirmed that the peak at 286 eV represented the repeat unit in a PEG molecule. Zeta potential results re-confirmed PEG’s presence at the surface. Cell uptake studies of PEG modified drug particles were performed using a flow cytometric assay and suggested that the neutral charge of the nanoshell results in decreased phagocytosis after 48 hours of incubation. Using paclitaxel nanoparticles with a breast cancer cell line, the nanoparticles were found to be effective in the absence of an excipient such as Cremophor EL. Strategies to create multifunctional nanoparticles and to deliver nanoparticles orally will also be discussed.
03/24/2011: TBD, by Diana Huffaker, University of California, Los Angeles – Cancelled.
04/21/2011: The Role of Process Systems Engineering in the Quest for the Artificial Pancreas, by Professor Francis J. Doyle III, Chemical Engineering Department, University of California, Santa Barbara
Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease affecting approximately 3 million individuals in the US, with associated annual healthcare costs estimated to be $15 billion. Current treatment requires either multiple daily insulin injections or continuous subcutaneous (SC) insulin infusion (CSII) delivered via an insulin infusion pump. Both treatment modes necessitate frequent blood glucose measurements to determine the daily insulin requirements for maintaining near-normal blood glucose levels. More than 30 years ago, the idea of an artificial endocrine pancreas for patients with type 1 diabetes mellitus (T1DM) was envisioned. The closed-loop concept consisted of an insulin syringe, a blood glucose analyzer, and a transmitter. In the ensuing years, a number of theoretical research studies were performed with numerical simulations to demonstrate the relevance of advanced control design to the artificial pancreas, with delivery algorithms ranging from simple PID, to H-infinity, to model predictive control. With the advent of continuous glucose sensing, which reports interstitial glucose concentrations approximately every minute, and the development of hardware and algorithms to communicate with and control insulin pumps, the vision of closed-loop control of blood glucose is approaching a reality. In the last 8 years, our research group has been working with medical doctors on clinical investigations of control algorithms for the artificial pancreas. In this talk, I will outline the difficulties inherent in controlling physiological variables, the challenges with regulatory approval of such devices, and will describe a number of algorithms we have tested in clinical experiments for feedback control of the artificial pancreas, based on model predictive control.
09/08/2011: Materials Challenges in Electrochemical Energy Storage Technologies, by Sri Narayan, USC
10/13/2011: Correlated imaging of nanostructure form and function, by Lincoln Lauhon, Northwestern University
11/10/2011: TBD, by Ramamoorthy Ramesh, University of California, Berkeley
09/24/2009: Functional Biomaterials for Drug and Vaccine Delivery, by Professor David A. Putnam, School of Chemical and Biomolecular Engineering,Cornell University
The Putnam laboratory’s research interests focus on the application of chemical, biological and engineering principles to solve problems in medicine, particularly drug delivery. We focus our efforts in three areas. First, we work to synthesize new biomaterials derived from structures represented in natural human metabolic pathways, and attempt to understand how their molecular compositions provide functionality to the biomaterials. Second, we work to engineer new ways to entice bacteria to express, correctly fold and stabilize non-native proteins, particularly for the formulation and delivery of antigenic sequences for vaccines. Third, we work to understand how the molecular composition and architecture of water-soluble polymers collectively function to transfer nucleic acids (i.e., plasmid DNA, siRNA, microRNA) from the bloodstream to cells.
This seminar will encompass two areas, showing our current work in the design and synthesis of surgical biomaterials for the treatment of postoperative seroma, and in the engineering of E. coli to enhance the immunogenicity of poorly antigenic proteins.
10/22/2009: SIZE MATTERS: Mechanical Properties of Materials at Nano-Scale, by Professor Julia Greer, California Institute of Technology
While “super-sizing” seems to be the driving force of our food industry, the direction of materials research has been quite the opposite: the dimensions of most technological devices are getting ever smaller. These advances in nanotechnology have a tremendous impact on parts of the economy as diverse as information, energy, health, agriculture, security, and transportation. Some of the examples include data storage at densities greater than one terabit per square inch, high-efficiency solid-state engines, single-cell diagnostics of complex diseases (e.g. cancer), and the development of ultralight yet super-strong materials for vehicles, with the component sizes comprising these technological devices reduced to the sub-micron scale. The functionality of these devices directly depends on their structural integrity and mechanical stability, driving the necessity to understand and to predict mechanical properties of materials at reduced dimensions. Yield and fracture strengths, for example, have been found to deviate from classical mechanics laws and therefore can no longer be inferred from the bulk response or from the literature. Unfortunately, the few existing experimental techniques for assessing mechanical properties at that scale are insufficient, not easily accessible, and are generally limited to thin films. In order to design reliable devices, a fundamental understanding of mechanical properties as a function of feature size is desperately needed; with the key remaining question whether materials really are stronger when the instrumental artifacts are removed, and if so then why and how.
A key focus in Professor J.R.Greer’s research is the development of innovative experimental approaches to assess mechanical properties of materials whose dimensions have been reduced to nano-scale not only vertically but also laterally. One such approach involves the fabrication of nanopillars with different initial microstructures (single crystalline, nano-crystalline, amorphous, etc.) ranging in diameter from 100 nm to 800nm by using Focused Ion Beam (FIB) and micro-fabrication approaches. Their strengths in uniaxial compression and tension are subsequently measured in a one-of-akind in-situ mechanical deformation instrument developed in the Greer lab. This instrument is called SEMentor, as it is comprised of the Scanning Electron Microscope (SEM) and Nanoindenter, which allow for precise control of displacement and loading rates, as well as for simultaneous video capture. Some representative images of various nano-sized mechanical testing specimen are shown in Figure 1. In this seminar we will discuss the differences observed between mechanical behavior in two fundamental types of crystals: face-centered cubic (fcc) and body-centered cubic (bcc), as well as of nano-crystalline Nickel and amorphous metallic glasses with nano-scale dimensions. In a striking deviation from classical mechanics, we observe a SMALLER IS STRONGER phenomenon in single crystals manifested by the significant (~50x) increase in strength of as material size is reduced to 100nm. To the contrary, nano-crystalline materials tend to exhibit the opposite trend: SMALLER is SOFTER. Finally, metallic glasses, whose Achilles’ heel has always been the occurrence of catastrophic failure at very small strains, exhibit non-trivial ductility when reduced to nano-scale. Furhtermore, unlike in bulk where plasticity commences in a smooth fashion, all of these materials exhibit numerous discrete strain bursts during plastic deformation. These remarkable differences in the mechanical response of nano-scale solids subjected to uniaxial compression and tension challenge the applicability of conventional plasticity models at the nano-scale. We postulate that they arise from the effects of free surfaces, leading to the significant differences in dislocation behavior for the case of crystals, grain-boundary activity for the case of nano-crystalline solids, and shear transformation zones in metallic glasses. and serve as the fundamental reason for the observed differences in their plastic deformation. These mechanisms and their effect on the evolved microstructure and the overall mechanical properties will be discussed.
11/19/2009: Conjugate Nanostructures and Their Potential Applications, by Professor Rina Tannenbaum, School of Materials Science and Engineering, Georgia Institute of Technology
Recent developments in science and technology have created exciting opportunities to blend life sciences and engineering. On the one hand, extensive research in the last two decades focused on the chemical and physical properties of nanoscale metal and semiconductor materials and their potential applications in cutting‐edge technologies such as microelectronics and optoelectronics. On the other hand, recent insight into the genetic and molecular underpinnings of cellular bioprocesses, indicate an immediate practical application of these nanomaterials in medical diagnostics and targeted therapeutics, resulting in the possible development of modular, personalized medicine platforms, especially in the area of cancer detection and treatment. The basic approach afforded by nanomaterials is the design of multi‐component nanoscale structures that encompass the various functionalities necessary for the in‐situ, simultaneous identification, mapping, targeting and destruction of cancer cells, which may afford the opportunity of a paradigm shift in the area of cancer therapy. The lecture will be accessible to a broad audience of researchers with an interest in biomaterials, nanotechnology and personalized medicine.
01/28/2010: Programming cell-fate decisions with RNA control devices, by Professor Christina D. Smolke, Stanford University
Cellular behavior is encoded and controlled by complex genetic networks. Synthetic genetic devices that interface with native pathways can be used to change natural networks to implement new forms of control and behavior. Significant recent work on the engineering of synthetic gene networks has been limited by an inability to interface with native networks and components. To overcome these limitations, we have developed RNA control devices that process and transmit molecular signals that are received by integrated sensor domains to targeted protein level outputs, linking computation and logic to gene expression and thus cellular behavior in mammalian cells. The modularity inherent in our device design supports the rational assembly of these RNA controllers from independent components exhibiting basic functions and the extension to more sophisticated information processing schemes, highlighting the potential of synthetic biology strategies to support the rapid engineering of cellular behavior. Coupled with technologies that enable the de novo generation of new RNA sensor components, RNA devices allow researchers to construct various user-programmed information processing operations in living systems. The application of these molecular devices to developing new disease treatment strategies such as targeted molecular and cellular therapeutics will be discussed.
02/25/2010: Nano-Enabled Technologies, by Professor Z.L. Wang, School of Materials Science and Engineering, Georgia Institute of Technology
Developing novel technologies for wireless nanodevices and nanosystems are of critical importance for sensing, medical science, defense technology and even personal electronics. It is highly desired for wireless devices and even required for nanodevices to be self-powered without using battery. It is essential to explore innovative nanotechnologies for converting mechanical energy, vibration energy, and hydraulic energy into electric energy, aiming at building self-powered nanosystems. We have demonstrated innovative approaches for converting mechanical energy into electric energy by piezoelectric zinc oxide nanowire (NW) arrays. Based on the piezoelectric potential created by strain in nanowires and in conjunction with the presence of a Schottky barrier at the contact, our research has demonstrated the technological road map from fundamental science, engineering scale-up to technological applications of the nanogenerators. As of today, we have demonstrated “self-powered” nanosensors that work by harvesting energy from the environment. In addition, three-dimensional solar cells have been fabricated by integrating optical fiber with nanowires for developing “hidden”, concealed and high efficiency solar cells. This talk will focus on the energy technologies developed using ZnO nanowires as the platform.
03/25/2010: Engineering Protein Fitness Using Cellular Quality Control Mechanisms, by Matthew DeLisa, University of Cornell
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
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
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
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
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
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
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
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
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
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
“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
02/22/2007: Mechanisms of Transport Across the Alveolar Epithelial Barrier: From Ions to Nanoparticle, by Dr. Edward D. Crandall, USC
Interest in nanotechnology has greatly expanded in recent years, driven in part by growth in manufacturing and applications that range widely from fabrication of useful nanoscale circuitry and robotics to biological applications of nanomaterials in imaging and transduction at the cellular and molecular levels. Nanoparticles promise to be useful for many biomedicine-related applications, yet their toxicity, trafficking characteristics across cells, and specific pathways and mechanisms of uptake into pneumocytes are not well known.
The lung can serve as a portal for entry for nanomaterials (ambient and/or manufactured) into the systemic circulation. Inhaled nanoparticles can be found in heart, bone marrow, blood vessels and other organs, and their most likely route of entry into the circulation is across the epithelia of the lung, especially the alveolar epithelium with its very large surface area and thin barrier thickness. Further knowledge about the mechanisms by which particles injure, interact with and/or are transported across the alveolar epithelium is thus of considerable importance for understanding health effects related to inhalation of nanoparticles in ambient air. Nevertheless, nanoparticle-based drug/gene delivery and other biological applications may be important to pursue, even though biocompatibility and toxicity of such nanomaterials are not yet well defined.
To explore interactions with the air-blood barrier of distal lung, nanoparticle injury of, uptake into and trafficking across alveolar epithelial cells were investigated. Polystyrene nanoparticles (PNP) of different surface charge and size were utilized as models of defined manufactured nanomaterials. Results indicate that (1) all PNP are non-toxic to the cells, (2) PNP translocate transcellularly across rat alveolar epithelial cell monolayers, and (3) transepithelial trafficking of PNP is markedly influenced by nanoparticle surface charge density and size. Specific mechanisms underlying these interactions remain to be fully determined
11/30/2006: De-Watering of Hunton Reservoir – What Makes It Work? by Dr. Mohan Kelkar, Department of Petroleum Engineering, University of Tulsa
Hunton Reservoir in Oklahoma represents one of the largest discoveries in Oklahoma in recent history. Since 1995, several fields in Hunton Reservoir have been exploited by various operators. The principle behind this exploitation remains the same. The wells produce large quantities of water, and along with it, significant quantities of gas, and sometimes, oil. Examination of various fields producing from Hunton reservoir indicates that the economic success from these fields is not uniform. Some fields produce significant quantities of oil, whereas, some fields only produce gas. In some fields, horizontal wells work the best, whereas, in some other fields, vertical wells do a good job. The water production from the fields ranges from as low as few hundred barrels per day to several thousands of barrels per day. In this presentation, we present the results from various fields to indicate the parameters needed in Hunton field to make it economically successful. We restrict our evaluation to parameters which can be easily measured or are readily available. These include log data (gamma ray, resistivity, neutron and density), initial potential data, production data (oil, gas, and water – if available) and well configuration (vertical or horizontal). By comparing the recovery of oil and gas to various reservoir parameters, we develop methodology for predicting the future success of the field. For example, a clear relationship exists between porosity of the rock and initial hydrocarbon saturation. Higher the oil saturation, better is the recovery factor. Initial potential is critical in determining the possible recovery. Horizontal wells cost 1.5 to 2 times more than vertical wells, but may not provide the additional recovery to justify the costs. Similar formations exist in other parts of the U.S. If we want to extend the success of some of the fields to other areas, we need clear guidelines in terms what is needed to exploit those fields. This presentation provides some of those guidelines based on the examination of the currently producing fields.
10/26/2006: Biomolecules, Nanostructures and Interfaces – Time Resolved Vibrational Spectroscopy of Materials and Material Transformations, by Prof. Dana D. Dlott, School of Chemical Sciences and Fredrick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign
In this talk I will discuss novel techniques of ultrafast laser vibrational spectroscopy and their applications to materials and material transformations. These techniques provide detailed pictures of molecular dynamics with the kind of ultrahigh time and space resolution that has previously been available only in computer simulations. Illustrative examples will be presented including: combustion of energetic materials containing nanoparticles, structural fluctuations at the active sites of proteins, energy transduction in molecular nanostructures and interfaces, and electrochemical processes at nanostructured fuel cell electrodes.
Bio: Dana D. Dlott received a B.A. degree from Columbia University in 1974 and a Ph.D. from Stanford University in 1979 under the supervision of Prof. Michael D. Fayer. In 1979 he joined the faculty at the University of Illinois. Dlott is an experimental physical chemist known for his novel applications of ultrafast nonlinear coherent spectroscopic methods to condensed phase dynamics. Current research in his laboratory includes studies of nanomaterials, molecular and biomolecular materials, shock compression science, fundamental mechanisms of energetic materials including nanotechnology materials, dynamics of surfaces and interfaces, electrochemical surface science, and applications of lasers in imaging science. He is an Alfred P. Sloan Fellow and a Fellow of AAAS, APS and OSA