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2012 Seminars

  • Studies of the 3D structure of the proton at JLab

    Nov. 30, 2012, 1:30pm-2:30pm, OE 134

    Dr. Harut Avakian, Thomas Jefferson National Accelerator Facility, USA

    Abstract:

    In recent years parton distributions, describing longitudinal momentum, helicity and transversity distributions of quarks and gluons, have been generalized to account also for transverse degrees of freedom. Two new sets of more general distributions, Transverse Momentum Distributions (TMDs) and Generalized Parton Distributions (GPDs) were introduced to describe transverse momentum and space distributions of partons. Great progress has been made since then in measurements of different Single Spin Asymmetries (SSAs) in semi-inclusive and hard exclusive processes providing access to TMDs and GPDs respectively. Facilities world-wide involved in studies of the 3D structure of the nucleon include HERMES at HERA, CLAS and Hall-A at JLab and COMPASS at CERN. Significant progress has been achieved recently in lattice measurements of TMD moments. Studies of TMDs and GPDs are also one of the main driving forces of the JLab 12 GeV upgrade project. In this talk we present an overview of the latest developments in studies of TMDs and GPDs and discuss newly released results, ongoing activities, as well as some future measurements at JLab12.classes.

    Biography:

    Dr. Avakian is a staff scientist at Jefferson Lab. Dr. Avakian received his Ph.D. from Yerevan Physics Institute in 1986. His main research focus is the study of the orbital motion of quarks and in particular the observation and interpretation of single-spin asymmetries (SSA) in semi-inclusive and exclusive electroproduction of hadrons and photons with polarized beam or target. His major accomplishment was the first observation of single-spin asymmetries (SSA) in hadron electroproduction in deep inelastic scattering at HERMES and first observation of beam spin asymmetries at JLab.

  • Physics identity development through meaningful classroom experiences

    Nov. 16, 2012, 1:30pm-2:30pm, OE 134

    Dr. Zahra Hazari Assistant Professor of Engineering & Science Education Assistant Professor of Mathematical Sciences Clemson University

    Abstract:

    Many students are disempowered in physics classes, finding them to be more difficult, unpleasant, narrow, and masculine when compared to other subjects. What, then, can physics teachers do to help students, particularly females, engage in more personally meaningful ways when learning physics? Beginning with an examination of overall gender differences in physics, this talk addresses the ways in which physics classroom experiences shape students’ physics identities. I will draw on evidence from three studies: two national survey studies as well as qualitative case studies of four purposefully-selected high school physics teachers (NSF 0115649, 0624444, and 0952460). Employing a physics identity framework, I will discuss why such a perspective is a powerful lens of analysis, how it has been operationalized, and how high school physics experiences are related to student engagement and physics identity development. The ultimate goal of this work is to begin to shift the tide of disinterest in physics by engaging students in more personally meaningful ways during their physics classes.

    Biography

    Zahra Hazari is an assistant professor in the Department of Engineering & Science Education at Clemson University. Before completing a Ph.D. in science education from the Ontario Institute for Studies in Education (OISE) of the University of Toronto, she earned a B.S. in physics and mathematics and an M.S. in physics. She was a national postdoctoral fellow of the Social Sciences and Humanities Research Council of Canada and the Harvard Smithsonian Center for Astrophysics. Her current work is supported by an NSF CAREER grant and an NSF Gender grant, and has been featured in Science Magazine, the APS News, Scientific American, and LiveScience.

  • Applying current research findings from cognitive and neurosciences to university physics teaching

    Nov. 9, 2012, 1:30pm-2:30pm, OE 134

    Dr. Dedra Demaree, Department of Physics, Oregon State University

    Abstract:

    In 2007, Dedra Demaree was hired to lead reform of the introductory courses at Oregon State University. Assessment of this reform led (among other projects) to a PhD student developing a validated survey on student physics identity, and extensive consideration of learning environments and what motivates student participation. In parallel work, Dr. Demaree collaborates with the University of Cape Town to evaluate bridging programs at the undergraduate and graduate level to help under-prepared students succeed in physics programs. Part of this work has centered on studying what impacts how a student responds to a physics question, and has led to the development of a cognitive model for activation of resources and effective use of working memory during problem solving. These projects seem very unrelated: community learning environments and resource activation/working memory use, however, the latest research findings from cognitive and neurosciences provide a compelling information on how the brain is wired that requires us to see these as intrinsically connected. To borrow from Steve Alsop (2005) "the complexity of science education necessitates recognition of the mutually constitutive nature of cognition and affect.... At all levels, cognition and affect are seen as fused, inseparable... affect should be seen as axiomatic, at times making science education difficult, but above all else, actually making science education possible." This talk will share current understanding of how the brain works with applications to the teaching of university physics.

    *

    Short bio:*

    Assistant Professor of Physics at Oregon State University since September 2007, Visiting Professor of Physics at College of the Holy Cross (Massachusetts), 2006-2007, PhD in Physics from The Ohio State University, 2006 Primary Research: Assessing student learning in reformed teaching environments, Developing and assessing models for faculty adoption of reformed teaching, Program evaluation for success of minorities at the graduate and undergraduate level (in South Africa), Studying the role of discourse in student affect and engagement Other physics expertise: Computational particle physics, Cold atom physics, Atomic-beam experiments

  • Neuroimaging Methods to Explore the Brain

    Nov. 2, 2012, 2pm-3pm, Ryder Business, Room 120

    Dr. Todd Parrish, Department of Radiology, Northwestern University

    Abstract:

    Magnetic resonance imaging has revolutionized how medicine and neuroscience view the anatomy and physiology of the human brain. Utilizing advanced neuroimaging methodology it is possible to investigate normal learning, plasticity changes as a result of therapy and treatment, and the effects of drugs on physiology and function. An overview of how imaging can be used to investigate the neuroanatomical and physiological changes will be discussed and current research results provided to demonstrate the wide range of applications that neuroimaging has to offer.

  • Nuclear Physics at Jefferson Lab: Present and Future

    Oct. 26, 2012, 1:30pm-2:30pm, OE 134

    Dr. Lei Guo Department of Physics Florida International University

    Abstract:

    Quantum Chromodynamics (QCD) has been established as the theory that describes the strong interactions between quarks and gluons, the building blocks of our universe. However, many fundamental questions remain unanswered, particularly in the non-perturbative regime where QCD cannot be solved analytically. The role of confinement in the structure of strong interaction hadrons, the spectrum of different species of particles, as well as the origin of nucleon spins, are just a few example of the exciting problems that nuclear physicists from around the world seek to address at Jefferson Lab. In the past decade, many results Jefferson Lab (JLab) have shed new perspectives on our understanding of the strong interactions. With the 12GeV upgrade currently undergoing at JLab, a new generation of experiments with high statistics and high precision will be conducted using the state-of-art facilities at JLab, promising further and better understanding of QCD, the spectrum of strong interacting particles, and the structure of nucleons. Physicists from Florida International University actively participate in many of these experiments. Recent results as well as future experiments will be reviewed.

    Biography: Bachelor: Peking University

    Ph.D. Vanderbilt University

    Postdoc: Jefferson laboratory

    Postdoc: Los Alamos National Laboratory

    Research Interest: Exotic Mesons, hyperon polarization, hadron spectroscopy, nuclear medium modification, color transparency (Jlab), cold nuclear matter effect (d-Au collision) at RHIC, Drell-Yan physics at Fermi Lab, etc.

  • Self-assembly of magnetic patterns using stress-engineering approach

    Oct. 19, 2012, 1:30pm-2:30pm, OE 134

    Dr. Leszek Malkinski, Associate Professor of Department of Physics and Materials Science, Advanced Materials Research Institute, University of New Orleans

    Abstract:

    Complex 3-dimensional microstructures can be designed using stress-engineering approach. This technology was introduced in 2000 by the group of Prinz for semiconductor films. Thin multilayered film patterns with residual stresses between dissimilar layers tend to bend, roll or twist when released from the substrate by selective etching. One can essentially use well known origami techniques to assemble flat patterns into very complex shapes. Deformation of the film patterns provides new functions of these 3-D structures and also changes properties of the constituting materials. In particular the link between, stresses, shape and magnetic properties of magnetic microstructures will be discussed. Potential applications of this technology will be indicated.

    Brief biographical sketch:

    In 1991 Dr. Leszek Malkinski received his PhD degree in Physics from the Institute of Physics of the Polish Academy of Sciences in Warsaw, Poland. He gained his professional experience working as a visiting scholar in several European and the U.S. research institutes. Since 2002 he is with the University of New Orleans, where he has joint appointment with the Department of Physics, where he has his teaching duties, and the Advanced Materials Research Institute, where he performs his research on technology, properties and applications of magnetic materials. He is an author of about 100 publications in this field. He has also been involved in organizing several conferences on magnetism and he serves as an editor-in-chief of a new open access journal Nanomagnetism and an editor of Journal of Materials.

  • Quantum transport on carbon nanotori in nanodevices and metamaterials - from effective models to non-equilibrium Green's function methods

    Oct. 12, 2012, 1pm-2:30pm, OE 134

    Prof. Mark Jack Department of Physics Florida A&M University

    Abstract:

    Graphene-based allotropes such as carbon nanorings hold the promise of completely new nanodevice and metamaterials applications due to the effects of magnetic flux and curvature on quantum transport on a nanoscale toroidal surface and the coherence of resulting electromagnetic moments. Modular symmetries due to rolling the flat graphene sheet to a two-dimensional manifold with toroidal geometry are predicted to significantly impact energy band structure and transport properties of physically distinct nanotori with different chiralities and dimensions. In addition to persistent current and Aharonov-Bohm effects under magnetic flux, new magnetic moments such as a new toroidal moment will be generated by the ring currents. In a metamaterial of these aligned nanoconstituents a significant enhancement of these quantum signatures may be expected due to coherence of the individual electromagnetic responses. In a first step, electron transport on a carbon nanotorus is calculated in a tightbinding model for armchair and zigzag carbon nanotori between metallic leads using a recursive non-equilibrium Green's function method. Density-of-states, transmission function and the integrated source drain current can be calculated for realistic system sizes of 10,000 carbon atoms and more. A fast and numerically precise parallel software tool has been developed on a multi-core architecture that can incorporate additional effects such as electron-phonon coupling effects due to low-energy phonon modes, exciton transport, or electron-plasmon coupling terms in second- or third-nearest-neighbor type calculations.

    Short Bio:

    Dr. Mark Jack is associate professor at Florida A&M University’s Physics Department in Tallahassee, FL. He completed his Ph.D. in theoretical particle physics at the Humboldt Universität Berlin, Germany in 2000 on fermion-pair production at the CERN/LEP2 experiment and for linear collider physics. He was postdoc at UCLA’s Neurobiology Department from 2000 to 2002 investigating spike-train statistics in mice retinal ganglion cells due to natural visual stimuli. In 2003 he joined the faculty at Florida A&M University’s Ph.D. program in physics and has focused in his research on theory and simulation of quantum charge transport in carbon nanostructures and -devices. His current research interests are in the area of metamaterials, nanoplasmonics, organic photovoltaic materials and large-scale quantum transport simulations via high-performance computing. He is currently on sabbatical leave at the University of Central Florida’s NanoScience Technology Center and Physics Department. More information can be found at: http:/www.famu.eduindex.cfm?DepartmentofPhysics&AboutPhysics

  • Ricci Curvature Flow for General Shape Registration and Geometric Analysis

    Oct. 5, 2012, 1pm-2:30pm, OE 134

    Prof. Wei Zen School of Computing & Information Sciences FIU

    Abstract:

    Ricci flow has been successfully applied in the proof of Poincare’s conjecture, which deforms the Riemannian metric proportionally to the curvature, such that the curvature evolves according to a heat diffusion process. Ricci flow offers a powerful tool for shape registration and geometric analysis, which plays fundamental roles in a broad range of applications in engineering and medicine. This talk focuses on the theory of discrete surface Ricci flow, the computational algorithms and their applications in practice. Ricci flow has unique merits: (a) by Ricci flow, all shapes in real life can be unified to one of three canonical shapes, the sphere, the plane or the hyperbolic disk; (b) therefore, most 3D geometric problems can be converted to 2D image problems; (c) furthermore, this conversion preserves original geometric information. Ricci flow has been used to tackle the following fundamental problems in engineering and biomedicine: 3D human face registration and deformable surface tracking in computer vision; global surface parameterization in computer graphics; conformal brain mapping and virtual colonoscopy in medical imaging; homotopy detection in computational topology; delivery guaranteed greedy routing and load balancing in wireless sensor network, and so on. The future task is to explore Ricci curvature flow on volumetric geometric data and its efficiency for real-time geometric processing tasks.

    Short Bio:

    Dr. Wei Zeng is an assistant professor of the School of Computing and Information Sciences at Florida International University. Supervised by Harry Shum from Microsoft Research Asia and David Gu at Stony Brook, Dr. Zeng finished her Ph.D. thesis on “Computational Conformal Geometry Based Shape Analysis”. Her research interests include Computational Conformal Geometry, Computational Quasiconformal geometry, discrete differential geometry, discrete Ricci flow, geometric analysis, and their applications to surface matching, registration, tracking, recognition, and shape analysis. Her research areas span over medical imaging, computer vision, computer graphics and visualization, wireless sensor network, geometric modeling and computational topology. More information can be found at: users.cis.fiu.edu/~wzeng/ 

  • Giant Nernst Effect and Bipolarity in the quasi-one-dimensional metal Li(0.9)Mo(6)O(17)

    Sept. 21, 2012, 1:30pm-2:50pm, OE 134

    Prof. Joshua L. Cohn Department of Physics, University of Miami

    Abstract:

    The Nernst coefficient for the quasi-one-dimensional metal, Li(0.9)Mo(6)O(17), is found to be among the largest known for metals (~500\ microV/KT at T~ 20 K), and is enhanced in a broad range of temperature by orders of magnitude over the value expected from Boltzmann theory for carrier diffusion. A comparatively small Seebeck coefficient implies that Li(0.9)Mo(6)O(17) is bipolar with large, partial Seebeck coefficients of opposite sign. A very large thermomagnetic figure of merit, ZT~0.5, is found at high field in the range T~ 35-50 K.

  • Nanotechnologies, environmental sensing and bioinformatics – the impending transformation of public

    Sept. 14, 2012, 1:30pm-2:50pm, OE 134

    Dr. Shekhar Bhansali, Department of electrical & computer engineering, Florida International University

    Abstract:

    Micro and nano sensors that identify biological entities has been one of the more popular applications of nanotechnologies. With the maturatization of the technologies, there is an increased focus on standardized interfaces for wearable devices to enable personalized health monitoring. Increased understanding of biology has led to greater appreciation of the fact that biologics and longitudinal health monitoring needs to be coupled with environmental triggers to gain a realistic understanding of human body responses. This talk reviews the current state of the art and needs for personalized environmental health monitoring systems to understand the effects of pollutants, chemicals, toxins, and radiation on human health. The talk highlights the role of nanotechnologies in enabling the transformation of healthcare from managing disease to managing wellness and explores the question, with a $10 gene sequence, unlimited data storage and affordable computation around the corner what needs to happen in the personalized environmental sensing space to really advance human health.

    The presentation also introduces ASSIST, one of the three Nano Engineering Research Centers funded by the National Science Foundation after a rigorous one year review.

    *

    About the speaker: * Shekhar Bhansali, PhD, is Alcatel-Lucent Professor and Chair of Electrical and Computer Engineering at Florida International University. Prof. Bhansali receiving his Ph.D. in Electrical Engineering from RMIT University in Australia (1997). A prolific researcher and mentor, he has published over 100 peer reviewed papers, holds 16 patents and has directed training programs that supported over 150 doctoral students in all areas of STEM. Dr. Bhansali has received numerous awards including the William R. Jones Outstanding Mentor Award, Alfred P. Sloan Foundation Mentor of the Year Award, and the NSF CAREER Award. Prof. Bhansali serves on the editorial boards of Recent Patents in Nanotechnology, and Technology and Innovation.

  • Conjugated polymer nanoparticles for labeling and delivery of biological interests

    Sept. 7, 2012, 1:30pm-2:30pm, OE 134

    Dr. Joong-Ho Moon, Department of Chemistry, Florida International University

    Abstract:

    Conjugated polymers (CPs) are fluorescent materials with superior photophysical properties and biocompatibility that are useful for sensitive labeling, detection, and delivery of biologically active substances. In this seminar, fabrication of highly bright conjugated polymer nanoparticles (CPNs) and its biological applications including two-photon imaging of endothelial cells in a tissue model and delivery of small interfering RNA (siRNA) to cancer cells will be presented. CPNs are promising cancer detecting probes with extremely high brightness, photostability, and non-toxicity. In addition to the outstanding photophysical properties, transfection of HeLa cells with the CPN/siRNA complexes resulted in significant down regulation of a target gene without cell viability inhibition, supporting that CPNs are promising multifunctional nanomaterials for biomedical applications.

  • Multimodal Functional Neuroimaging: Integration of fMRI and EEG/MEG data

    Aug. 31, 2012, 1:30pm-2:30pm, OE 134

    Prof. Jorge Riera Diaz, Department of Biomedical Engineering, Florida International University

    Abstract:

    The electroencaphalogram (EEG) and the functional magnetic resonance imaging (fMRI) constitute the prevailing tools to study the brain functioning in both healthy individuals and patients with a variety of neurological disorders. For about two decades, physicists and biomedical engineers have struggled to determine the biophysical mechanisms underlying these two neuroim-aging modalities. Recent efforts by different groups have been on: a) developing forward-generative models as well as strategies for their statistical inference, b) performing EEG-fMRI concurrent recording and data fusion, and c) establishing suitable animal models for specific brain dysfunctions. Here, I first review preliminary studies in humans where interesting problems related to these emergent research/technological lines are presented. Then, I discuss recent achievements by members of my group in Tohoku University, Sendai Japan, using animal models to examine how neuronal activity is translated into EEG and fMRI signals, and in which situations we must expect alterations in these signals, e.g. in the case of Alzheimer disease.

  • A Brief Introduction to Cosmology

    Aug. 24, 2012, 1pm-2:30pm, OE 134

    Richard Galvez, Department of Physics, Syracuse University

    Abstract:

    An introductory review on our present understanding of the beginning and evolution of the Universe will be presented. The role of general relativity, quantum field theory and quantum gravity in the standard inflationary cosmology will be discussed. Particular focus will be given to speculative less-mainstream ideas like holographic gauge/gravity dual models, string-motivated cosmological models, and even what simulations of supersymmetric lattice gauge theories can tell us about cosmology. Finally the topic of how observations can constrain and ground more exotic models will be discussed.