Dr. Kester will discuss several new initiatives including “repurposing generics” through nanotechnology; delivery of bioactive lipids through nanotechnology; delivery of molecular-based therapies through nanotechnology and delivery of polypeptides and biologics through ORAL nanotechnology, the next revolution.
In the late 1700s, the first industrial revolution powered mechanical equipment with water and steam. The second such revolution in the late 1800s employed electricity for the purpose of mass production. The third industrial revolution in the 1970s was based on electronics, information technologies and automation. We are now largely presumed to be living with the emergent fourth industrial revolution that is fusing our physical, digital, and biological experiences with an unprecedented pace of change and disruption across national and trade boundaries. This is a conversation about how a research-intensive university can respond to the evolving disruption — for instance, by integrating an interdisciplinary education with major research investments in areas of predicted disruption.
The Open Campus initiative of the Army Research Laboratory (ARL) is a collaborative endeavor, with the goal of building a science and technology ecosystem that will encourage groundbreaking advances in basic and applied research areas of relevance to the Army. Through the Open Campus framework, ARL scientists and engineers will work collaboratively and side-by-side with visiting scientists in ARL’s facilities, and as visiting researchers at collaborators’ institutions.
The dynamics of ferroelectric and multiferroic nanodomains have been probed under the constant irradiation of energetic electron beams and conventional contact mode piezoforce microscopy. The oscillation, faceting, and movement of nano-ferroelectric domains, domain walls, and periodicity of freestanding Pb(Zr0.52Ti0.48)O3 (PZT) nanocrystals and nanorods, and room temperature multiferroic PZT-Pb(Zr0.5Ti0.5)O3 will be discussed. The behavior of multiferroic domains under E-fields and M-fields will be presented in the context of change in domains probed by weak energy PFM technology. The faceting of PZT nanocrystals from circular disk geometry to a sharply hexagonal shape has been observed by high-resolution transmission electron microscopy (HRTEM). Triangular-shaped domains don’t show any oscillation or faceting. The behavior is analogous to that of spin structure and magnetic domain wall velocity oscillations in permalloy, involving overshoot and de-pinning from defects. A nondestructive E-beam with 300 kV energy was used to understand the actuation behavior of ferroelectric PZT/PVDF composite nanorods 1-5 microns in length and 50-200 nm in diameter under irradiation. It has been observed that nanorods move away almost 5 to 50 nm from the original position depending on the position and time of irradiation and probing/imaging. This mechanical deviation is reversible and robust in nature which indicates that it may be useful for future NEMS devices. Simulation and physical models of these nanostructures will be presented.
Engines and motors are everywhere in the modern world, but it is a challenge to make them work if they are very small. On the micron length scale, inertial forces are weak and conventional motor designs involving, e.g., pistons or flywheels cease to function. Biological motors work by a different principle and use catalysis to convert chemical to mechanical energy on the nanometer length scale. Together with Ayusman Sen and other colleagues at Penn State we have explored the concept of using catalysis to power synthetic nano- and micromotors. Bi- and trimetallic microwires are catalytically self-propelled in fuel-containing solutions at speeds that are comparable to those of flagellar bacteria. Despite the difference in propulsion mechanisms, catalytic motors are subject to the same external forces as natural micromotors such as bacteria. Therefore they follow the same scaling laws and exhibit similar emergent behavior (e.g., magnetotaxis, chemotaxis, schooling, and predator-prey behavior). Recently we have found that asymmetric nanowires also undergo autonomous motion and a range of collective behavior in fluids when excited by low power ultrasound. The acoustic propulsion mechanism may be particularly useful for diagnostic and biomedical applications because it is salt-tolerant and does not involve toxic chemical fuels.
Rising complex challenges to our environment, health, security, and economy in a global market call for new strategies for research that synthesize foundational principles and proven best practices with nascent discoveries and innovative new approaches. This presentation considers evolving university-government-industry partnerships to translate discovery to marketable innovations and examines the potential of emerging electrodynamic structures with unprecedented functionality in self-assembled biomimetic nanoscale metamaterials.
The large number of genes across eukaryotic genomes begs the question as to whether they are all fundamentally regulated in the same manner. Clearly, sequence-specific factors direct gene-specific regulation, but then do all downstream events proceed along a common path? To begin to address this question, we use ChIP-exo to map the precise contact points of proteins along genomic DNA. The near single-bp readout provides structural insights into how proteins are organized into complexes across genomes, and how they might position nucleosomes to regulate gene expression. Multiple classes of complexes occupy nucleosome-free promoter regions: an ensemble of sequence-specific factors and their coactivators, the core transcription machinery, chromatin remodelers and nucleosomes. This talk will focus on identifying common principles that determined how factors and chromatin organize themselves at promoters across co-regulated genes, and in genes in general.
Individual cells in a population are often somewhat different from each other. Measurements made on bulk cell populations do not capture the inherent heterogeneity of the cell population, and important insights can be missed. This talk will cover some technical challenges in analyzing individual cells, and present our recent progress in acquiring genome and transcriptome information from single microbial and mammalian cells, with a special emphasis on human adult neurons.
Many organisms fly in order to survive and reproduce. I am fascinated by the mechanics of flying birds, insects, and autorotating seeds. Their development as an individual and their evolution as a species are shaped by the physical interaction between organism and surrounding air. It is critical that the organism’s architecture is tuned for propelling itself and controlling its motion. Flying macroscopic animals and plants maximize performance by generating and manipulating vortices. These vortices are created close to the body as it is driven by the action of muscles or gravity, then are ‘shed’ to form a wake (a trackway left behind in the fluid). I study how the organism’s architecture is tuned to utilize the fluid dynamics of vortices. Here I link the aerodynamics of insect wings to that of bat, maple seed and bird wings. The methods used to study all these flows range from robot fly models to maple seeds flying in a vertical wind tunnel to freeze-dried swift wings tested in a low-turbulence wind tunnel. The study reveals that animals and plants have converged upon the same solution for generating high lift: a leading edge vortex that runs parallel to the leading edge of the wing, which it sucks upward. Why this vortex remains stably attached to flapping animal and spinning plant wings is elucidated and linked to kinematics and wing morphology. While wing morphology is quite rigid in insects and maple seeds, it is extremely fluid in birds. Here I show how such ‘wing morphing’ significantly expands the performance envelope of birds during both gliding and flapping flight. Finally I will show how these findings have inspired the design of new flapping and morphing micro air vehicles.
The interface between hard and soft condensed matter presents new and compelling research opportunities in the transport of energy and mass due to the dramatic contrasts in bond strength, chemical interactions, and transport modalities between these constituents. Often, however, when inorganic and organic materials are blended into composites, performance suffers and new failure modes appear. Here, I will discuss the design and understanding of transport properties in “hybrid” systems, which show the pivotal role that nanoscale interfaces can play in dictating macroscale transport properties.
Nanoscience is the science of materials in the size range between 1 and 100 nm, potentially demonstrating properties which are unusual for differently sized materials. Given the scale of the production and their potential deleterious environmental effects, nanomaterials are an emerging contaminant of great importance. The environmental risk of these nanomaterials is poorly constrained due to a fundamental lack of understanding and information on a range of issues. However, nanomaterials are of great potential benefit to the environment as sensors, in remediation and elsewhere. This talk will discuss the research in both areas and discuss tension and approaches at this interface.
The storage and release of water to streamflow is a fundamental watershed process. De- spite this, our understanding of the relationships between watershed storage state and streamflow magnitude are poorly understood, especially the roles of antecedent conditions, water redistribution patterns, and resulting hydrologic connectivity between uplands and streams. This presentation focuses on these concepts with examples from a highly instru- mented and data-rich watershed located in Central Montana.
Gold nanoparticles are well known to absorb and scatter light as a function of particle size and shape. Gold nanorods, in particular, show strong plasmon resonances that are tunable with aspect ratio in the near-infrared. The strong elastic scattering of these nanomaterials makes them good candidates for bioimaging agents, and the heat they generate makes them good candidates for photothermal therapeutics. A world-renowned expert in gold nanoparticle synthesis, Dr. Cathy Murphy will highlight both the biological applications and implications of these nanomaterials, will emphasize the importance of initial surface chemistry for their properties, and will present results of their interactions with living cells, organisms, and model ecosystems.
Dr. Alan Icenhour, became the Associate Laboratory Director (ALD) for the Nuclear Science and Engineering Directorate (NSED) at the Oak Ridge National Laboratory (ORNL) in February 2014. NSED operates state-of-the-art nuclear facilities and conducts technology development and application programs that impact a large range of fields from basic science to reactor development to national security. As ALD, Dr. Icenhour leads three research divisions (Fusion and Materials for Nuclear Systems, Nuclear Security and Isotope Technology, and Reactor and Nuclear Systems), one operating division (Nonreactor Nuclear Facilities), and the Consortium for Advanced Simulation of Light Water Reactors, the U.S. Department of Energy’s first energy innovation hub. NSED mission areas include research and development (R&D) for both fission and fusion technologies; advanced modeling and simulation; stable and radioactive isotope R&D and production; research, development, and deployment of technologies to address nuclear security challenges globally; and safe and efficient operation of ORNL’s nuclear facilities. Since July 2008, he has served as director of three ORNL divisions: the Global Nuclear Security Technology Division, the Fuel Cycle and Isotopes Division, and most recently, the Nuclear Security and Isotope Technology Division.
Paul C. Struik is head of the Centre for Crop Systems Analysis and professor of crop physiology at Wageningen University, Wageningen, the Netherlands. He obtained his PhD with distinction in 1983 from Wageningen University. Since 1986 he has been a full-time professor responsible for teaching and research in crop and grassland science. He has carried out research on forage crops, potato physiology, seed production technology, crop ecology, and the use of nonfood crops. He currently is involved in research projects on social and agronomic aspects of biodiversity in Africa, QTL-based modelling of crop growth and quality, micronutrient husbandry, modelling of basic processes in photosystems of C3 and C4 plants under stress, 3D modelling, and chain management of agricultural produce in Africa. He is (co-)/ author of more than 400 scientific papers, 15 books, and more than 160 papers in proceedings/books of abstracts. He has supervised over 85 PhD candidates and currently supervises about 30 PhD students.
Dr. Johan Foster focuses on advanced functional and supramolecular bio(nano)materials: design, synthesis, and engineering of bioinspired, biosourced functional polymers, supramolecular materials, and nanocomposites; stimuli-responsive materials; and biomedical materials; and has combined covalent and noncovalent interactions to create structured smart materials. Dr. Foster is a new Associate Professor in Virginia Tech’s Materials Science and Engineering Department and a new member of Virginia Tech’s Macromolecules and Interfaces Institute. He previously led a group of 8-12 researchers (Ph.D. students and post-docs) at the Adolphe Merkle Institute (AMI) in Switzerland, who focused on cellulosic nanocrystals, smart materials, nanocomposites, synthesis, functionalization, and biomedical implants. He came to Virginia Tech after doing a post-doctoral fellowship with Bert Meijer at Technical University Eindhoven, in The Netherlands, and a Ph.D. at Simon Fraser University in Canada.
The world as we know it today is heading towards an unsustainable energy future. The present carbon based energy system is insecure, inefficient and certainly unsustainable. Bold change is required in direction of policies, in redirecting and increasing support in search of new energy responding to the escalating increase in energy demand worldwide. One significant characteristic of fuels and energy is that all the issues have become global and the interest in evolving the technologies crosses borders and continents. An important evidence of global thinking in energy and fuels is the Worldwide Fuel Charter (WWFC). This unique document was issued for the first time in 1998 by four global automotive organizations from USA, Europe and Japan, plus 15 other national automotive organizations. The Charter aims to promote understanding of the fuel quality needs world-wide, to satisfy specific needs in accordance with technological development of vehicles.
In recent years, many disasters have occurred which resulted in damage to critical community healthcare functions. The 2011 Christchurch and 2010 Bío-Bío earthquakes, Hurricanes Sandy and Katrina, and tornadoes in Joplin, MO and Moore, OK all resulted in severe damage to local hospitals, putting great strain on the healthcare systems of these regions. The continued functionality of critical infrastructure, such as healthcare facilities, is necessary following a major event. Healthcare delivery facilities are essential in disasters: they provide emergency medical care related to the event and regular health services required to maintain the health of the community they serve. To provide adequate services to patients, healthcare facilities rely on a wide range of internal and external functions, each of which are part of a complex network of interacting systems. The loss of a single function can severely disrupt the ability to provide care during the critical first hours.
To improve the resilience of facilities like these, decision-makers first need a way to quantify their performance due to extreme loading from natural hazards, both predictively and retrospectively. Dr. Judith Mitrani-Reiser’s presentation will show a risk analysis framework for quantifying and predicting the loss, recovery, and resilience of healthcare facilities. The theoretical framework accounts for loss of service due to building and utility damage, as well as impacts to key personnel and resources/supplies needed to provide clinical and nonclinical services. Dr. Mitrani-Reiser’s presentation will also show a standardized methodology to collect and analyze field data of critical building systems to better correlate physical damage with loss of functionality of healthcare facilities.
"Pigs oink, dogs bark and regulators regulate" – an aphorism attributed to a former Commissioner of FDA, Dr. Frank Young, is likely very prescient when it comes to the subject of nanotechnology and the food supply. Although FDA has historically been a more "reactive" agency for fear of accusations of stifling technology, the agency is in the process of issuing guidelines for the use of nanotechnology despite the lack of evidence of any harm to consumers or even evidence of the use of nanotechnology being in the food supply. It is clear FDA sees an "opportunity" to regulate what is becoming a phenomenally game-changing, cross-cutting technology in any number of industries. In support of nanotechnology regulation for food, government agencies will cite ample precedent of previously unrealized threats including phocomelia (thalidomide), mesothelioma (asbestos workers), and even butter flavor in microwave popcorn manufacture ("popcorn lung" in workers) but will largely ignore the false alarms about genetically modified foods ("frankenfoods"), thimerosal in vaccines (autism), and cancer resulting from cell phones, aspartame, and saccharin.
The basic building blocks of flesh and bones depict submicron features. Cancer cells break apart from a primary tumor once there is a nutritional crisis in the tissue. These metastatic cells pass through layers of tissue and fat to get to the bloodstream. A new dimension to solid-state device fabrication at micro and nanometer scales is emerging that mimics what rogue cells do. The probing, detection, and characterization of biological entities is bound to unravel disease pathways at both molecular and cellular scales. This seminar will discuss work on the early detection of cancer at molecular and cellular scales. The integration of biomedical engineering, nanoscience, and nanotechnology with the living aspect differentiates focus in diverse areas like nanomanufacturing, molecular diagnostics, and chip-based recognition of cancer cells.
The Center for Biologically Inspired Design at GA Tech is a response to global challenges in education and sustainable technology development. Our goal is to facilitate, develop infrastructure for, and promote interdisciplinary research and education. This represents an effort to train scientists for increasingly complex problems in sustainability and develop novel and benign solutions for these problems. The Center for Biologically Inspired Design is led by Biology and comprised of faculty from a variety of engineering and science disciplines, as well as architecture and industrial design. These faculty rely on interdisciplinary approaches to solve today’s complex problems. A key activity is studying biological systems for principles that have high potential to function as a template for addressing human challenges, such as the development of urban infrastructure systems or enabling the solar power industry. In addition, we focus on developing the pedagogy for interdisciplinary collaboration using theories derived from cognitive and learning sciences, and science education. Here, bio inspired design serves as a template for creative and interdisciplinary interactions, requiring biologists, engineers, and designers to learn how to communicate across disciplines and transfer ideas from different domains in a fruitful effort. I will describe some of the challenges and successes that we have experienced in developing this educational and research effort.
There is more solar energy reaching the earth in one hour than the combined worldwide human consumption of energy in one year. Tapping into this enormous potential requires reducing the cost of solar collection and storage and increasing the efficiency of solar energy conversion to electricity. To this end, the U.S. Department of Energy SunShot Initiative calls for an aggressive reduction in the overall systems costs by 75% to make solar energy cost competitive with other forms of energy, without subsidies, by the end of the decade. In just 3 years into the decade-long initiative, we are over the halfway mark in the cost reductions needed towards achieving grid parity of solar-generated electricity. In fact, 2013 was a record year for solar with the U.S. surpassing the 10 GW milestone. While the initial cost reductions are impressive, much work remains in addressing the challenges toward fully realizing the SunShot goal. The talk will highlight the technical challenges, and the transformative and holistic approaches being pursued to address the goals of cost reduction and greater adoption of solar energy technologies. The talk will also discuss the importance of energy storage as more renewable sources join our nation’s power generation fleet.
For the last few decades, engineering has produced marvelous machines and devices. With increasing understanding of living cells, there are possibilities of developing biological machines where engineering precision meets the variability of life. Can order emerge from such variability and chaos? If so, then one can envision machines with unprecedented capabilities, as they would carry the footprints of the evolutionary journey of life. Here, we demonstrate an elementary biological machine. A large family of micro-organisms such as bacteria and spermatozoa wag or twist hair-like flagella to swim. At this small scale, locomotion is challenged by large viscous drag and negligible inertial forces. The organisms must generate time irreversible deformation of their flagella to produce thrust. Mimicking this strategy, we developed a self-propelled, microscale flagellar biohybrid swimmer by combining a unique fabrication and cell culture technique with a slender body hydrodynamics model . Our swimmer consists of a PDMS filament shaped like a spermatozoa with a short, rigid head and long, slender tail on which cardiomyocytes are selectively cultured. The cardiomyocytes contract and bend the filament. The bending wave travels towards the tail end of the filament generating a fluid drag, which acts as a thrust to propel the swimmer forward against its longitudinal drag. The swimmer demonstrates the feasibility of an autonomous synthetic biohybrid swimmer at small scale that can be incorporated into more complex designs.
 Nature Communications, Jan 17, 2014, DOI:10.1038/ncomms4081
Weight, performance and durability are critical drivers for any aerospace system. Reduced vehicle and system weight can enable reduced fuel consumption and emissions (aircraft), reduced launch costs and complexity (spacecraft) and increased payload capacity. Performance improvements can enhance vehicle and mission capability. System and vehicle durability are important since they impact mission safety and effectiveness. Nanotechnology has the potential to help address each of these concerns by enabling such developments as lightweight, multifunctional materials; low-power and low-volume sensors with high selectivity and sensitivity; radiation-hard, fault-tolerant electronics; and higher output energy generation and storage devices. NASA has developed a 20-plus-year plan for the development of nanostructured materials and devices and their insertion into NASA missions. This presentation will provide a perspective on future needs identified in the roadmap and a few examples of current research activities focused on meeting those needs.
In the DOE Energy Innovation Hub, the Joint Center for Artificial Photosynthesis, we are developing a non-biological, artificial photosynthetic system that will generate fuels directly from sunlight, water, and carbon dioxide. This talk will include a discussion of a feasible and functional prototype and blueprint for an artificial photosynthetic system that is composed of only inexpensive, earth-abundant materials, as well as results, recently achieved at Caltech, which demonstrate technical progress towards the development of the artificial photosynthetic prototype.
Small nanoparticles (30-50 nm) containing an amorphous precipitate of calcium phosphate with a wrapping lipid bilayer have been developed to deliver impermeable drugs and genes to intracellular targets. Plasmid DNA, siRNA, peptide antigen and small chemo drugs have been delivered with LCP to tumor and liver. Dr. Leaf Huang will discuss both mechanism and application of the nanoparticles.
Natural scientists must combine temporal and spatial information to develop an understanding of the biophysical dynamics that shape the distribution of natural resources, organisms, communities, and chemicals. Recent developments in sensor technology are transforming temporal and spatial resolution of data collection. These developments will likely alter how data are collected, and potentially alter our most conceptualizations of how natural systems work.
This seminar will explore the evolution of reference frames in hydro-ecology (hydraulics, fish movement, biogeochemistry), and how different measurement techniques have caused the re-conceptualization of reference frames. The seminar will then expand into environmental law, with the notion that U.S. environmental law is just as sensitive to frames of reference as fluid mechanics, cartography, and any other discipline that studies natural phenomena, and that the assumed reference frame predetermines how we conceive of environmental problems and solutions far more than we realize. The emergence of novel measurement technologies will not only change hydro-ecology, but has the potential to invert accepted applications of environmental law.
The development of a sustainable energy portfolio to mitigate climate change is one of the great challenges we are facing today. The United States has set goals to develop a bio-based industry for fuel, power, and other products. At the same time, we are seeing an increasing investment in renewable energies, like wind and solar. The development of new technologies leading to a clean energy economy will be critical to long-term economic competitiveness and the ability to win the future. This investment has to be coupled with next generation manufacturing technologies such as additive manufacturing.
These goals have engendered a growing interest in the production of biomass and its conversion to fuels and materials. Novel deconstruction methods focusing on enzymatic catalysis of biomass allowing targeted access to cheap sugars derived from cellulose and hemicellulose and will permit the exploration of other plant cell wall components such as lignin. Lignin, among other applications, is evaluated as precursor for carbon fiber production. Traditional carbon fiber, derived from fossil fuel precursors is currently used in many high-end applications such as light-weighing of high-end sports cars to increase performance. The production of carbon fiber at lower cost will allow the use in conventional vehicles leading to substantial weight saving. Weight reduction has a direct impact on fuel economy and is a targeted goal to achieve future fuel standards. Lignin carbon fiber researchers at ORNL developed a novel process for lignin carbon fiber spinning which reduces the carbon fiber cost significantly, opening the door for use in conventional vehicles. Combined with the use of alternative fuel sources and electrification, this can break petroleum’s vise grip on transportation.
This presentation will give an overview of various research areas within ORNL focusing on the integration of technologies towards a sustainable community in the future.
For the entire history of mankind, the treatment of disease has been limited by the simple fact that diagnosis follows the appearance of symptoms. While we do administer prophylactics in cases of known exposure and high risk, and recommend regular check-ups to identify onset of illness based on genomic analysis and epidemiologically determined environmental risk factors, the question still remains - how would medicine change if pre-symptomatic diagnosis were commonplace? From the simplest perspective, drugs work better when applied earlier in infection and could in cases be replaced by immune system adjuvants. More interesting would be the capability of pre-symptomatic determination of an unknown infection state, for example during the 2003 SARS coronavirus or 2009 Influenza outbreaks, or after a biothreat.
To address the challenge, we have developed a platform capable of detecting single nanoparticles and viruses with high throughput, no amplification and at low cost. Interferometric, multi-color imaging on simple substrates provides the ability to rapidly scan and identify size, shape, orientation and material properties of single nanoparticles and viruses. To detect and size pathogens, our Interferometric Reflectance Imaging Sensor (IRIS) shines light from multi-color LED sources sequentially on viruses and nanoparticles bound to the sensor surface, which consists of a silicon dioxide layer atop of a silicon substrate. Interference of light reflected from the sensor surface is modified by the presence of particles producing a distinct signal that reveals the size of the particle. In our approach the dielectric layered structure acts as an optical antenna optimizing the elastic scattering characteristics of nanoparticles for sensitive detection and analysis. We have successfully detected 35 nm and 50 nm radius particles and H1N1 viruses (illustrated in the conceptual picture, right) with accurate size discrimination. Au nanoparticle tagging allows us to detect attogram (sub-picomolar) quantities of biomarkers on a platform capable of high-throughput screening. Our current limit of detection is < 100aM for protein in serum and < 500aM in whole blood. From the perspective of disease diagnosis and treatment, we have recently achieved sensitivity of less than 104 pfu/ml of an Ebola virus analog in serum, and explored multiplexed detection of Ebola, Marburg and Lasa pseudotypes at pre-symptomatic concentration in blood.
Computational materials science brings a physics-based materials design capability within reach. However, materials design for radiation response is challenging because it deals with inherently collective mechanisms operating at multiple time and length scales. I will present a design strategy built on reduced order mesoscale models, which afford simplified descriptions of the essential physics of complex, collective materials phenomena. As an illustration, I will explain how metallic glasses may be altered to achieve tailored radiation response.
Two phenomena have been discovered by the author: 1 the anomalous motion of impulsively loaded nonlinear structures and 2 the post-chaotic self-organization with final states formed according to their natural modes. Under pulse loads of certain durations and amplitudes, various elastic-plastic structures exhibited unusual chaotic motion and reverse buckling with final deflections in the direction opposite to the loads, and in some cases with unexpected loss of axial symmetry. Impulsively stretched rods buckled and obtained final shapes similar to the classical shapes of statically compressed slender rods. There is a region of extremely high sensitivity to small perturbations in the load parameters, material properties, energy dissipation, the computational mesh, single- or double-precision calculations and integration scheme (explicit, implicit or their combinations). In this region, several reliable numerical models based on commonly used differential equations of motion predicted conflicting deformation patterns. These two phenomena may have implications in various non-mechanical systems (such as economics, finance, politics, biology, etc.) modeled by similar equations and analyzed by using similar numerical methods.
Presented in partnership with the Virginia Tech Department of Engineering Science and Mechanics.
During the first portion of this seminar, extensive PIV data collected from a scaled down 3 blade, 3 x 5 turbine array is shown. In order to understand how large-scales motions play a role in providing mean kinetic energy (MKE) to the array, low dimensional tools based on a proper orthogonal decomposition (POD) are used to analyze the spatially developing velocity field inside the scaled array. From this analysis, modal decomposition of the Reynolds stresses and fluxes of the MKE are constructed. Thus, from these modal expansions it is established that low order modes have large contributions to Reynolds shear stress regardless of analysis domain. In addition, it will be shown that mean kinetic energy transport resulting from Reynolds shear stress typically serves to bring energy into the array while transport terms associated with Reynolds wall-normal stress typically removes energy from the array. Furthermore, it will be shown that the sum of the first 13 modes for the mean fluxes contributes 75% of the total Reynolds shear stress in the domain.
The concept of coherent transfers of energy is employed here as means to uncover the scales responsible for the entrainment of mean kinetic energy into the array. The major contributions to the MKE entrainment are achieved by large-scale motions associated with sums of the Reynolds shear stress, (idiosyncratic) modes. Thus, the sum of the first 9 modes yield 54% of the total energy entrainment, with scales given by L ~ 13D associated with this sum. From these results, it is clear that scales of the order of the total wind farm size are those, which are critical in determining how much power can be extracted from the atmospheric boundary layer. In addition, during this seminar it will be shown that dispersive stresses are also important in the energy entrainment and dissipation in wind arrays with complex topography and where proximity between turbines exists.
Dr. Castillo’s presentation is co-sponsored by the Virginia Tech Center for Renewable Energy and Aerodynamic Testing (CREATe). Established in the fall of 2012, CREATe brings together faculty interested in wind energy who possess expertise in related technical areas. CREATe is designed to be interdisciplinary and is coordinated with Virginia Tech’s Institute for Critical Technology and Applied Science.
Mitosis is critical for the faithful segregation of genetic material among the two daughter cells. During mitosis, a eukaryotic cell assembles a bipolar spindle from dynamic microtubules. Chromosome segregation is accomplished by the concerted function of the mitotic spindle and kinetochores, mega-protein assemblies formed at centromeres of chromosomes. Kinetochores attach end-on to spindle microtubules and generate forces that orient and move sister chromosome pairs to the spindle equator at metaphase and segregate them to opposite spindle poles in anaphase. Kinetochores are also the sites of an efficient intracellular signaling mechanism called the spindle assembly checkpoint that has a major role in preventing inaccurate chromosome segregation. Unequal segregation of the chromosomes can have catastrophic consequences (chromosomal instability) leading to tumorigenesis and birth defects. Despite the progress we have made to characterize many of the molecules and mechanisms involved in mitosis, we are still lacking a completely mechanistic understanding of how kinetochores attach properly to spindle MTs and how they serve to move and segregate the chromosomes accurately. My research is focused towards understanding how kinetochores accomplish these key functions during mitosis.
The National Cancer Institute (NCI) Center for Strategic Scientific Initiatives (CSSI) is a component of the NCI’s Office of the Director focused on emerging advanced technologies that have the potential of uniquely impacting the full spectrum of cancer basic and clinical research. The Center is tasked with planning, developing, executing, and implementing rapid strategic scientific and technology initiatives that keep the Institute ahead of the scientific curve with respect to potential new exciting areas and discoveries. This may involve direct development and application of advanced technologies, synergy of large scale and individual initiated research, and/or using available federal mechanisms to forge novel partnerships that emphasize innovation, trans-disciplinary teams and convergence of scientific disciplines. With an emphasis on complementing the scientific efforts of other NCI divisions, CSSI’s efforts seek to enable the translation of discoveries into new interventions, both domestically and in the international arena, to detect, prevent and treat cancer more effectively. This presentation will highlight various programs and their associated accomplishments within CSSI’s broad scientific portfolio of programs (Clinical Proteomic Tumor Analysis Consortium, Alliance for Nanotechnology in Cancer, Physical Sciences-Oncology Centers, Innovative Molecular Analysis Technologies, and Provocative Questions) and describe future directions and opportunities.
Solid oxide fuel cells (SOFCs) are promising candidates for future energy conversion systems because of their high energy conversion efficiency than those for conventional heat engine systems and other types of fuel cells. However, there are several major technical hurdles to overcome before SOFC’s wide applications, namely (1) impurity effects on anode, (2) developing interconnect coatings to mitigate Cr-poisoning related issues, and (3) developing highly efficient and stable cathode. Infiltration methods have been widely employed to improve the oxygen reduction reaction (ORR) kinetics of SOFC cathode. The principal assumption in infiltration is that infiltrants having high oxygen absorption capabilities enhance oxygen flux into the cathode and thus improve the cathode performance. However, few systematic investigations exist on ORR mechanisms in infiltrated SOFC cathodes. In this talk, we report our studies on several issues fundamental related to infiltrated cathode: (1) Improving Data Accuracy of Electrical Conductivity Relaxation (ECR) Method; (2) Using ECR to Characterize Oxygen Interfacial Exchange Behavior; and (3) ORR Modeling in infiltrated Cathode. The preliminary results show that over-potential, as well as other materials’ intrinsic characters, have important effect on ORR behavior in infiltrated cathode.
An exciting feature of nanotechnology is that between 1 and 100 nm length scale the behavior of a system or material becomes size dependent opening unique possibilities. For example, at cryogenic temperatures, current through one or an array of ~10 nm nanoparticles is non-Ohmic due to local charging by a single electron. I will describe an array of 10 nm Au nanoparticles made by directed self-assembly to form a two dimensional (2D) network of one dimensional (1D) necklaces. The “polymerized nanoparticle” necklaces exhibit a robust single electron effect at room temperature. Furthermore, by modulating the electrical double layer around the necklace array, we have demonstrated the first single electron transistor operating in water. In this talk, I will describe the electrical, optical, and magnetic characteristics of these systems and their applications to biology, especially photosynthesis.
The National Renewable Energy Laboratory’s (NREL) National Wind Technology Center (NWTC), the nation’s premier wind energy technology research facility, fosters innovative wind energy technologies for land-based and offshore wind through its research and testing facilities and extends these capabilities to marine hydrokinetic water power. Dr. Fort Felker will present an overview of these exciting research areas in the context of increasing worldwide demand for wind power.
The Institute for Sustainable and Renewable Resources (ISRR) is a research center of the Institute for Advanced Learning and Research (IALR) in Danville, VA. The ISRR’s mandate focuses on the use of plant biology to enhance economic and community development in Southern Virginia. To achieve this, the ISRR has targeted their efforts in several areas, using expertise in plant tissue culture, molecular biology, biochemistry, genomics, breeding and plant transformation. Research areas have focused on the development of high value horticultural and forestry crops, the development and propagation of bioenergy crops, and the identification of novel products/bio-renewables from plants. This presentation will provide an overview of the various projects taking place at the IALR, and how they are being used to create economic opportunities for the region.
Securing energy supply is one of the grand challenges we are facing today and it is difficult to envision a plausible solution without nuclear power. Dr. Petrovic will provide an overview of the current nuclear power technology and discuss research directions aimed at developing new nuclear power plants. New plant designs are expected to offer improved characteristics with respect to safety, economics and waste management. Examples of representative nuclear plants and systems addressing these requirements will be presented.
Dr. Petrovic will then introduce a new reactor concept, Integral Inherently Safe Light Water Reactor (I2S-LWR). This concept aims to improve safety and economics of future nuclear plants, through significant innovations, at the same time remaining anchored to the proven Light Water Reactor (LWR) technology. I2S-LWR design concept employs reactor configuration with an integral primary circuit to implement inherent safety features, at the same time keeping the plant power at a GWe level. This requires innovations in the enabling technologies – safety approach and novel design of nuclear fuel and primary circuit components. I2S-LWR is being developed under a DOE Integrated Research Project (IRP) research grant, recently awarded to a multidisciplinary team of 11 national and international organizations, including the Virginia Tech Nuclear Engineering Program.
Co-sponsored by VTIP.
ICTAS (MC 0193)
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