9:45 Entanglement entropy at the BCS-BEC transition
Noah Bray-Ali, Letian Ding, Rong Yu, Stephan Haas
University of Southern California
Recent experiments on cold fermionic atoms near a Feshbach resonance suggest that it is possible to tune from a Bose-Einstein condensate (BEC) of tightly bound atom pairs to a state, analogous to the one introduced by Bardeen, Cooper and Shrieffer (BCS) to describe superconductivity in metals, consisting of more loosely bound pairs. Although intuitively quite distinct, the states have identical symmetry, and in some cases can be connected adiabatically. Entanglement entropy provides a natural way of formalizing the intuitive distinction between these two types of pairing, since it is sensitive to the subtle, long-range correlations that differ in the two states. In the case of "p-wave" pairing, a quantum phase transition separates the two states, and we have computed the universal behavior of the entanglement entropy near the critical point. Away from the critical point, we find that the BCS phase exhibits a logarithmic correction to the dominant "area law" behavior of the entanglement entropy, in contrast to the constant correction observed in the BEC phase.

10:00 The Effects of Dephasing on DNA Sequencing via Transverse Electronic Transport
Matt Krems, M. Di Ventra, Y. Persin, M. Zwolak
UCSD
We study theoretically the effects of dephasing on DNA sequencing in a nanopore via transverse electronic transport. To do this, we couple classical molecular dynamics simulations with transport calculations using scattering theory. Previous studies, which did not include dephasing, have shown that by measuring the transverse current of a particular base multiple times, one can get distributions of currents for each base that are distinguishable. We introduce a dephasing parameter into transport calculations to simulate the effects of the ions and other fluctuations. These effects lower the overall magnitude of the current, but have little effect on the current distributions themselves. The results of this work further implicate that distinguishing DNA bases via transverse electronic transport has potential as a sequencing tool. This work has been funded by NIH.

10:15 Potassium Carbonate (K2CO3) Fusion Curve Re-examined; New Experiments at 5GPa
Samuel Pottish, Qiong Liu, Matthew L. Whitaker, Wei Liu, Baosheng Li
California State University Long Beach
A series of experiments were performed in a 1000-ton uniaxial split- cylinder multi-anvil apparatus (USCA-1000; Kennedy Press) to determine the temperature at which a high purity Potassium carbonate (K2CO3) powder melts at 5GPa. Based on the previous study the extrapolated melting temperature was 1119øC at 5GPa. This study was performed to test these predictions at 5GPa. These experiments bracketed the melting temperature of this material to be 1190 ñ 13.04 - 1200 ñ 5.8 øC at 5GPa. Future work will involve thermodynamic calculations using a third-order BirchˆMurnaghan equation of state (EOS) and a detailed EOS analysis for crystalline- liquid thermodynamic equilibrium to find the best pressure dependence of the liquid compressibility value (K‚0) at 5GPa. This research was supported by REU program EAR 0754233 and NSF grants EAR00135550 and EAR0635860 to B. Li.

10:30 Optimization of Exchange Spring NiFe/SmCo and NiFe/SmFe Thin Films
Jesse Burgess, Jiyeong Gu, Ph.D.
California State University Long Beach
Exchange-coupled hard/soft bilayer systems, consisting of NiFe/SmCo and NiFe/SmFe, were deposited onto Si substrates via DC magnetron sputtering. Hysteresis loop measurements were made by DC magnetometry. For very thin NiFe/SmCo bilayer systems (≤ 1000 Å), the properties of the reversible soft-layer switching regime were found to vary greatly with respect to the deposition temperature, hard-layer Sm content, and the relative thicknesses of the hard and soft layers. The characteristic exchange spring effect, which was more easily achieved in ≥ 1000 Å samples, was often lost when these parameters fell outside of an acceptable range of values. In NiFe/SmFe systems, the reversible switching of the soft-layer was sharper, and occurred over a much smaller applied magnetic field range, than for NiFe/SmCo. The magnetic field required to achieve soft-layer saturation was also an order of magnitude smaller, making it more responsive to weaker applied fields.

10:45 Visualization of molecular orbitals and the related electron densities
Maciej Haranczyk, d chemist who work with molecules (in contrast to nuclear physics, astrophysics etc).
Computational Research Division, Lawrence Berkeley National Laboratory
When plotting different molecular orbitals with consistent contour values, one can create illusions about the relative extension of charge distributions. We suggest that the comparison is not biased when plots reproduce the same fraction of the total charge. We developed an algorithm and software that facilitate this type of visualization. This presentation will illustrate the problem on a few molecular systems and demonstrate how it can be addressed with tools developed by us. This work is supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

11:00 Fidelity approach to the disordered quantum XY model
Silvano Garnerone, T. Jacobson, S. Haas, P. Zanardi
USC
We study the random XY spin chain in a transverse field by analyzing the susceptibility of the ground state fidelity, numerically evaluated through a standard mapping of the model onto quasi-free fermions. It is found that the fidelity susceptibility and its scaling properties provide useful information about the phase diagram. In particular it is possible to determine the Ising critical line and the Griffiths phase regions, in agreement with previous analytical and numerical results.

11:15 Characterization of Ar and Kr Kα self-emission in clustering gas jets
Nathan Kugland, T. Döppner, C. G. Constantin, A. Kemp, S. H. Glenzer, C. Niemann
UCLA and LLNL
Kα self-emission from Ar and Kr has been characterized by x-ray spectroscopy and x-ray imaging. The Kα x-rays were produced by irradiating clustering Ar and Kr gas jets with ultra-high intensity (10²⁰ W/cm²), ultra-short pulse (150-700 fs) lasers. These sources are very high contrast (defined as the ratio of Kα to continuum radiation) and the Kα emission area is millimeter-scale. Such qualities make these sources useful for high-contrast diffraction and for backlighting large objects in extended-source geometries.

11:30 Enhanced Energy Loss from Reconnections with a Vortex Mesh
Ingrid Neumann, R.J. Zieve
UC Davis
We have experimentally observed that a superfluid 4He vortex moving in a cylindrical cell looses energy up to eight orders of magnitude more rapidly than expected from bulk mutual friction alone. Here we are reporting on a computational investigation into the discrepancy between early studies on mutual friction in superfluid 4He and the results of our own experiments in a vibrating wire cell. Specifically, we examine the possibility that reconnections with a mesh of small vortices pinned to the cell wall dominate the energy loss in our experimental geometry. We find that as the vortex moves and reconnects with pinned mesh vortices it dissipates energy at a rate exceeding that expected from mutual friction alone by 200%. Factors studied in our simulations which contribute to this enhanced energy dissipation will be discussed.

11:45 High Pressure Studies on Cyclopentane
Jimmy Hernandez-Bello, Michael Pravica, Sergey Stkachev
University Of Nevada in Las Vegas
We have performed Raman Spectroscopy studies on Cyclopentane at high pressures up to 21.5 GPa using a diamond anvil cell. The experiments were carried out using the off-line Raman spectrometer system in the 16BM-B beamline in Sector 16 of the APS at Argon National Laboratory. Cyclopentane was loaded using an immersion technique to avoid vaporization of the sample at ambient temperature. The results at ambient pressure match most of the results previously reported on the literature which only go up to 4 kilobar at low temperature. In the present study we measured Raman spectra of cyclopentane at ambient temperature up to 21.5 GPa observing a new phase transition occurring around 2.1GPa.

9:30-noon,FRIDAY,OCTOBER 17 Session I Room 326&327
9:30 The prediction of a new relativistic gravitational effect that can be measured by the NASA Lunar Reconnaissance Orbiter (LRO) Spacecraft.
Alexander Mayer
Pritzker Fellowship
In Volume II of the Feynman Lectures on Physics (Chapter 42-6) Feynman presents a gedanken experiment in which clocks in the nose and the tail of an accelerating rocket demonstrate the phenomenon of gravitational time dilation. The argument rests on only two principles: the constant velocity of the speed of light and the Equivalence Principle. Circa 1965, Feynman presented a physics class at Caltech with a variation of this gedanken experiment in which the two clocks are at the same axial coordinate in the rocket, separated by a lateral distance. The same principles of relativity imply a symmetric relativistic time dilation between the two clocks. It is apparent that the principles of relativity invalidate the Newtonian concept of a gravitational equipotential surface just as they invalidate the Newtonian concept of universal space and time. Predictive calculation of this very small relativistic transverse gravitational redshift for a real astrophysical gravitational field involves a difficult calculation that was impractical without modern computers and software (i.e., Mathematica). A prediction of the effect produced by the Moon's gravitational field and anticipated to be measured by the LRO will be presented. In the past the observed effect would have been interpreted as a "gravitational anomaly" or an atmospheric effect.

9:45 Temporal contribution to gravitational WKB-like calculations
Andrea Arias~de~Gill, Valeria Akhmedova, Terry Pilling, Douglas Singleton
CSU Fresno
Recently, it has been shown that the radiation arising from quantum fields placed in a gravitational background (e.g. Hawking radiation) can be derived using a quasi-classical calculation. Here we show that this method has a previously overlooked temporal contribution to the quasi--classical amplitude. The source of this temporal contribution lies in different character of time in general relativity versus quantum mechanics. Only when one takes into account this temporal contribution does one obtain the canonical temperature for the radiation. Although in this letter the specific example of radiation in de Sitter space-time is used, the temporal contribution is a general contribution to the radiation given off by any gravitational background where the time coordinate changes its signature upon crossing a horizon. Thus, the quasi-classical method for gravitational backgrounds contains subtleties not found in the usual quantum mechanical tunneling problem.

10:00 Concepts of Two Time Physics
Shih-Hung Chen, Professor Itzhak Bars
University of Southern California
Starting from the M-theory motivations for introducing the two time concept, I will quickly review the resolution of the most important difficulty of having a theory with more than one time, namely the ghost problem. I will explain how this problem is solved in the context of 2T-physics by introducing an SP(2,R) gauge symmetry that acts on phase space (X,P) and makes covariant position and momentum indistinguishable at every instant. I will quickly mention the consequences of 2T-physics for 1T-physics, which is in the form of hidden symmetries and dualities. These duality relations among 1T theories are like the relations among different shadows of the same 3D object on a 2D wall. These ideas have been successful in describing the usual Standard Model of particle physics and General Relativity in 3+1 dimensions as shadows of corresponding 2T field theories. The benefit of the 2T-physics formulation is to unify diverse 1T-physics systems via these hidden predicted dualities which can be checked through computation or experiment. There additional consequences of phenomenological interest which will be outlined in this talk.

10:15 Anomaly versus WKB/tunneling methods for calculating Unruh radiation
Douglas Singleton, Valeria Akhmedova, Terry Pilling, Andrea de Gill
California State University, Fresno
In this talk we critique and compare the anomaly method and WKB/tunneling method for obtaining radiation from non-trivial spacetime backgrounds. We focus on Rindler spacetime (the spacetime of an accelerating observer) and the associated Unruh radiation since this is the prototype of the phenomena of radiation from a spacetime, and it is the simplest model for making clear subtle points in both tunneling and anomaly methods. Our analysis leads to the following conclusions: (i) a straightforward application of the consistent and covariant anomaly method does not give the correct temperature for some metrics (e.g. Rindler spacetime) and in some cases (de Sitter spacetime) the two methods disagree with one another; (ii) the tunneling method can be applied in all cases, but it has a previously unnoticed temporal contribution which must be accounted for in order to obtain the correct temperature; (iii) the "detailed balance" method of doing the WKB/tunneling calculations gives the wrong temperature for the radiation when one takes both spatial and temporal contributions into account.

10:30 Machian Solution of Hierarchy Problem
Merab Gogberashvili
California State University, Fresno
The new interpretation of Mach's principle of mass of a particle being a measure of the interactions of this particle with all other gravitating particles inside its causal spheres is introduced. It is shown that within some alternative model of gravitation that incorporates this principle, the Machian influence of the universe can reduce Planck's scale to the electro-weak scale and the large number that is needed to explain the hierarchy between the scales is the amount of gravitating particles inside the universe horizon. Our model can lead to new observable effects at cosmological distances and close to the sources of a strong gravitational field.

10:45 Origin of the Quantum Universe
R. Cunningham
Individual
A phenomenal diagram depicts the initial condition (that which preceeded the universe), symmetry breaking, infinite heat details of the first energy cascade, and the spectral tower as the beginning of the second energy cascade. The latter is the source of the high temperatures and energies for quantum particle creation and relativity theory creation (since both must arise from the same events). The origin of spacetime is shown. The origin of quantum particles is shown on a descending algorithmic ladder over a quantum field theory time line. A comparison is included indicating the Large Hadron Collider (LHC) goal of locating the Higgs particle and mechanism.

11:00 The Parity Illusion
Robert Close
ClassicalMatter.org
When viewed in a mirror without theoretical prejudice, all known physical processes appear to proceed as if matter and anti-matter were exchanged. The simplest explanation for these observations is that spatial inversion (or parity, P) exchanges matter and anti-matter. If so, then the conventional parity operator is incorrect. We show that the conventional derivation of the Dirac parity operator is indeed flawed. The probability density $\bar \psi \gamma^0 \psi =\psi^\dagger \psi $, which is the time component of the probability current 4-vector, is erroneously taken to be a function of the matrix $\gamma^0$. This illusory functional dependence incorrectly requires that $\gamma^0$ preserve its sign under spatial inversion. This error results in a mixed-parity vector space, defined relative to velocity, which is otherwise isomorphic to the spatial axes. The conventional parity operator inverts only two of these three axes. A proper parity operator is derived which correctly identifies the matrices in the probability current 4-vector and inverts all three of the relative-velocity axes. The new parity operator exchanges matter and anti-matter, consistent with experimental observations.

11:15 Non-commutative micro-black holes evaporation and life times at the LHC.
Piero Nicolini, Roberto Casadio
CSU Fresno & Trieste University
Non-commutative black holes are characterized by a minimum mass which would result in a remnant after the "evaporation SCRAM", the shut down of thermal emission of radiation. We numerically study the decay of neutral non-commutative black holes for up to ten spatial dimensions and typical parameters that would make their production possible at the LHC. Neglecting possible accretion mechanism, we find that decay-times are extremely short.

11:30 Schroedinger's Universe- Origin of the Natural Laws
Milo Wolff, real Universe will be very excited.
MIT (retired)
This paper(1) describes Erwin Schroedinger's concept of the Wave Structure of Matter (WSM) within a reader-friendly and math format of the properties of the quantum "space" we live in. In 1937 Schroedinger wrote(2): "What we observe as material bodies and forces are nothing but shapes and variations in the structure of space. Particles are schaumkronen." (appearances). He believed quantum waves were real, not probabilities with particles hidden inside. He abolished the material particle, removed paradoxes of 'wave-particle duality, and collapse of the wave-function. But was ignored for sixty years. Einstein and Dirac agreed using the philosophy of truth. But also were ignored. 'Truth is no match for belief'. References (1): "Schroedinger's Universe- Origin of the Natural Laws (2008), Amazon.com. (2) Schroedinger- Life and Thought (1989), Cambridge U. Press. (3) APS-DPF, http://members.tripod.com /mwolff.

2:00-4:15pm,FRIDAY,OCTOBER 17 Session II Room 324&325
2:00 Electric field induced manipulation of static and dynamic optical and spatial properties of coupled quantum dots
Yashwant Verma, C. G. L. Ferri, S. N. Ghosh, M. Gallardo, D. F. Kelley and S. Ghosh
School of Natural Sciences, University of California, Merced, CA 95344, USA
We present a novel way to induce structural order in chemically synthesized GaSe QDs quantum dots (QD) by embedding them in a matrix of nematic liquid-crystal (NLC) molecules. Photoluminescence (PL) from the QD-NLC mixture exhibits large red-shift in the emission spectrum when compared to that from isolated QDs. This shift is between 30 and 50 nm, implying the formation of strongly coupled QD aggregates. Dynamic Light Scattering measurements on isolated and QD-NLC matrix reveal the aggregates to be composed of several tens of QDs, while PL measurements show that their emission is strongly polarized along their long axes. These structures can further be spatially re-aligned in situ without destroying the inter-dot coupling by the application of an in-plane electric field. The applied field continuously rotates the aggregates by almost 90ø resulting in a commensurate variation in the axis of the emission polarization. The degree of this re-orientation is found to be a function of the strength of coupling between the aggregated QDs. Time-resolved measurements reveal a faster excitonic recombination (tau_agg = 600 ps) in the QD-NLC matrix in comparison to that in isolated QDs (tau_QD = 3 ns) which is attributed to facile energy transfer processes. The aggregate recombination rate is linearly enhanced with increasing electric field which we infer is a result of the selective re-orientation mentioned above. Our result is a first step towards the possibility of forming and electrically manipulating large-scale ordered structures using chemically synthesized QDs, which will prove valuable for applications in diverse fields. This work was supported by ARO.

2:15 Ultra-fast x-ray Thomson scattering measurements from shock-compressed plasmas
Andrea Kritcher, P. Neumayer, J. Castor,T. Döppner,R. Falcone, O. Landen, H. Lee, S. Glenzer
University of California Berkeley, Lawrence Livermore National Laboratory
X-ray Thomson scattering measurements of the temperature and density of shocked solid-density plasmas are presented. Results provide the first experimental validation of modeling of compression and heating of shocked matter with a temporal resolution of approximately 10 ps. This diagnostic is opportune for inertial confinement fusion experiments that will achieve plasmas at extreme densities, e.g., on the National Ignition Facility, which will require high temporal resolution for characterization of short-lived states of compression. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work was further supported by DOE grant, NA-16 Intermediate Facility Initiative and the Lawrence Scholar Program fellowship.

2:30 Time-evolution of the grain size distribution in random nucleation and growth crystallization processes
Anthony Teran, Ralf B. Bergmann, Andreas Bill
Dept. of Physics & Astronomy, California State University Long Beach
The logarithmic-normal (lognormal) distribution is one of the most frequently observed distributions in nature and describes a large number of physical, biological and even sociological phenomena. Despite this fact, the derivation of this distribution from first principles has been obtained from probability theory only, generally applied to fragmentation processes. We propose a novel derivation of lognormal-type distributions by introducing a differential equation describing random nucleation and growth crystallization processes. The equation is solved analytically. We discuss the time-evolution of the distribution and show how the lognormal is obtained in the asymptotic limit of large times. The resulting expression is applied to the grain size distribution of crystallized Si-films. We gratefully acknowledge support from the Research Corporation and the SCAC at CSU Long Beach.

2:45 Electrical Characterization of Bipolar Metal-Oxide Resistive Switching
Stephen Tsui, N. Das, Y.Y. Xue, Y.Q. Wang, C.W. Chu
California State University San Marcos
Material systems that exhibit a reversible nonvolatile resistance alteration are of considerable interest for their potential to become the basis for the nonvolatile memory technology of the future. In particular, such a resistive switching has been identified in the interface between a Ag deposited electrode and a Pr0.7Ca0.3MnO3 thin film in response to the polarity of an applied electric pulse. Although the phenomenon has been reproduced by several groups, debate continues over the physical mechanism behind this controllable resistance change, be it electromigration, chemical doping, or Schottky-like barriers. Based on electrical transport characterization with particular emphasis on impedance spectroscopy, we suggest that the effect originates in a local structural rearrangement. The key to controlling the switch may therefore be the manipulation of interfacial defects.

3:00 Apertureless near-field optical microscopy study of the growth of Silicon Nitride (Si3N4) islands on a Si substrate
yohannes abate, Y. Romanyuk, D. Krier, S. R. Leone, J. Stiegler, A. Huber and R. Hillenbran
University of California Berkeley and LBNL
Apertureless near-field scanning optical microscopy (ANSOM) is used to study optical material contrast of epitaxially grown Silicon Nitride (Si3N4) islands on a Si substrate. The scattering of a linearly polarized (p-polarized) 633 nm laser is modulated by an oscillating metallic probe, and the scattered light is detected by homodyne amplification coupled with high-harmonic demodulation. Experimental results are provided that show nanometer-scale material-specific image contrast between Si3N4 and Si. The image contrast between silicon nitride islands and the Si substrate is qualitatively explained by a dipole-coupling model. The visible ANSOM images are compared to IR ANSOM images that show structures that do not correlate with topographic counterparts, and these substructures are explained by the local change of the dielectric function due to a variation of the chemical composition of the sample.

3:15 A Mössbauer Spectrometry Study of Thermally-Activated Electronic Processes in LixFePO4
Hongjin Tan, Joanna Dodd and Brent Fultz
California Institute of Technology
The solid solution phase of LixFePO4 with different Li concentrations, x, was investigated by Mössbauer spectrometry at temperatures between 25C and 210C. The Mössbauer spectra show a temperature dependence of their isomer shifts (IS) and electric quadrupole splittings (EQ), typical of thermally-activated, electronic relaxation processes involving 57Fe ions. The activation energies for the fluctuations of EQ and IS for Fe3+ are nearly the same 570meV, suggesting that both originate from charge hopping. For the Fe2+ components of the spectra, the fluctuations of EQ occurred at lower temperatures than the fluctuations of IS, with an activation energy of 512meV for EQ and 551meV for EIS. The more facile fluctuations of EQ for Fe2+ are evidence for local motions of neighboring Li+ ions. It appears that the electron hopping frequency is lower than that of Li+ ions.

3:30 Static high pressure infrared spectroscopic studies on triamino-trinitro-benzene (TATB)
Brian Yulga, Michael Pravica, Zhenxian Liu, Oliver Tschauner, Sergey Tkachev
University of Nevada - Las Vegas
Static high-pressure experiments utilizing diamond anvil cells (DACs) provide an alternative method to shockwave studies for extracting precise information on the physical and chemical properties of energetic materials. Due to mechanical constraints (e.g. small sample sizes and apertures), synchrotron radiation sources are ideal for probing the structure of materials at the molecular level. Infrared vibrational spectroscopic studies of TATB at high pressure conditions (to ~35 GPa) were conducted at the National Synchrotron Light Source (NSLS, Brookhaven National Laboratory). Results indicate primarily that there is no phase transition in TATB in the studied pressure range; however, fine changes in the vibrational spectra indicate subtle changes in structure that warrant further investigation and analysis.

3:45 Grain Size Distributions in Iron Phthalocyanine Thin Films
Paul Gentry, K. Paul Gentry, Thomas Gredig
Department of Physics & Astronomy, California State University, Long Beach
Many electric and optical properties of organic thin films depend on the precise morphology of grains. Iron phthalocyanine thin films are grown on sapphire substrates at different temperatures to study the effect of grain growth kinematics and to experimentally quantify the grain size distribution in organic thin films. The substrate temperature is varied from room temperature to 260øC. The grain size is measured for each sample with an atomic force microscope and the data is processed and analyzed with well-known image segmentation algorithms. For relevant statistics, for each sample more than 3,000 grains are evaluated. The data show large asymmetric growth of the grain size from a spherical to an elongated needle-like shape. The size along the major axes increases from about 35nm to 200nm and from 25nm to 90nm along the minor axes. The grain size distribution resembles a Gaussian (lognormal) distribution for lower (higher) temperature samples, respectively. The results are discussed within the context of an analytical random nucleation growth model, which results in lognormal-like distributions. This work was supported by a Scholarly and Creative Activity Award and Start-up Funding from the College of Natural Sciences and Mathematics at California State University, Long Beach.

4:00 Third Sound in Superfluid Films Adsorbed on Carbon Nanotubes
Emin Menachekanian, Hossie Fard, Anshul Kogar, Lara Mitchell, Guanyu Zhu, Gary A. Williams
University of California, Los Angeles/Physics Department
We have observed the propagation of third sound waves in thin superfluid He films adsorbed on carbon nanotubes at 1.3 K. The nanotubes are sprayed onto a plexiglass substrate, forming a tangle of interconnected tubes that is about 15 microns thick and 4 cm in length. We have used both single-wall nanotube bundles of mean diameter 5 nm and multiwall nanotubes with diameters averaging 15 nm. A heater and bolometer at opposite ends of the resonator allow detection of standing-wave third sound modes, and the third sound speed can be deduced from the resonant frequencies. On the multiwall tubes we have seen re-entrant superfluidity near the superfluid onset point of 3 atomic layers of adsorbed helium.

2:00-4:15pm,FRIDAY,OCTOBER 17 Session II Room 326&327
2:00 PET and Protons
Jeffrey Schmall
CSU Fresno
The basic underlying motivation of using protons to treat cancer is that protons, being charged particles, have an increased cross section for interaction as their energy decreases. This allows for the Bragg Peak phenomenon, which make protons ideal for treating deep seated tumors while sparing surrounding healthy tissue. The protons mainly lose energy via columbic interactions, but they can also have nuclear interactions with the target material. This research mainly studies these nuclear interactions by looking for the production of specific isotopes which under go positron decay allowing the annihilation photons to be detected outside the body. A PET detector system inside the treatment room would allow for the imaging of short lived isotopes, mainly O15. The goal of the research is to characterize the data received by the detector system to allow for range verification and QA of dose deposited. The research was done at the University of Pennsylvania Hospital, under the Medical Physics department.

2:15 Compact neutron generator for associated particle imaging
Ying Wu, Paul Hurley, Qing Ji, Joe Kwan, Ka-Ngo Leung
Lawrence Berkeley National Laboratory/University of California, Berkeley
We present recent work on a prototype compact neutron generator for associated particle imaging (API). API uses alpha particles that are produced simultaneously with neutrons in the deuterium-tritium (D(T,n)α) fusion reaction to track the position of the neutrons. This method determines the spatial position of each neutron interaction and requires the neutrons to be generated from a small spot in order to achieve high spatial resolution. The ion source for API is designed to produce a focused ion beam with a beam spot diameter of 1-mm or less on the target. We use an axial type neutron generator with a predicted neutron yield of 10⁸ n/s for a 50 μA D/T ion beam current accelerated to 80 kV. The generator utilizes a RF planar spiral antenna at 13.56 MHz to create a highly efficient inductively-coupled plasma at the ion source. Experimental results show that beams with an atomic ion fraction of over 80% can be obtained while utilizing only 100 watts of RF power in the ion source. A single acceleration gap with a secondary electron suppression electrode is used in the tube. Experimental results, such as the current density, atomic ion fraction, electron temperature, and electron density, from ion source testing will be discussed.

2:30 The Effect of an External Magnetic Field on Laser Beam Propagation
Bradley Pollock, L. Divol, S.H. Glenzer, J.D. Moody, D. Price, G.R. Tynan, and D.H. Froula
University of California, San Diego
Laser propagation through underdense plasma in the presence of an external magnetic field has been investigated at the Jupiter Laser Facility, Lawrence Livermore National Laboratory. The plasma is formed by focusing a 5 ns, 100 J, 1w (1054 nm) laser pulse through an f/50 optical system to the center of a tube containing He gas at a neutral density of ~2x10¹⁸ cm^-3. The magnetic field (5 T), aligned parallel to the laser axis, is produced by a solenoid supplied by a pulsed-power system. Transmission through the plasma is measured with a Transmitted Beam Diagnostic (TBD), providing temporal resolution better than 100 ps. We present results indicating that the laser pulse begins to spray outside of its vacuum f-cone within the first nanosecond of propagation. The addition of the magnetic field delays the onset of beam spray by an additional 2 ns. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was partially funded by the Laboratory Directed Research and Development Program under project tracking code 06-ERD-056. LLNL-ABS-407415

2:45 Aerosol Optics of Summer 2008 California Wildfires: Comparison with a Normal‚ Month
Madhu Gyawali, Ian Arnold , Dr.Pat Arnott
UNIVERSITY OF NEVADA RENO
Hundreds of wildfires in Northern California were sparked by lightning during the summer of 2008, resulting in downwind smoke for the months of June and July associated with the flaming and smoldering stages of the fires. These fires are consistent with a growing trend towards increasing biomass burning worldwide. Climate impacts from the smoke depend critically on the smoke amount and aerosol optical properties. We report comparison of aerosol optics measurements in Reno Nevada made during the very smoky summer month of July with the relatively clean, average month of August. Photoacoustic instruments equipped with integrating nephelometers were used to measure aerosol light scattering and absorption at wavelengths of 405 nm, and 870 nm. Total aerosol optical depth was measured with a sun photometer operating at 430nm, 470nm, 530nm, 660nm, 870nm and 950nm. These measurements document the intensity of the smoke optical impacts downwind. They are processed further to reveal a strong variation of the aerosol light absorption on wavelength, indicating the presence of light absorbing organic carbon and perhaps wavelength dependent absorption caused by black carbon particles coated with organic and inorganic particulate matter. On the day with most smoke in Reno (July 10, 2008), Angstrom coefficients for absorption as high as 3.6 were found for wavelengths of 405 nm and 870 nm, with the corresponding single scattering albedo near 0.92 at 405 nm. Aerosol optical depths of 3.5 were found for 430 nm on July 10th from the sun photometer measurements. A roughly fourfold increase in aerosol optical quantities was observed between the months of July and August 2008, attesting to the large average effects of biomass aerosols from the California wildfires. The Œnormal‚ month of August exhibits surprisingly low Angstrom exponents for aerosol light absorption at mid day when the single scattering albedo is highest, likely as a consequence of the wavelength dependence of aerosol light absorption by particles coated with non absorbing organic and inorganic matter.

3:00 Scattering of Light in Born-Infeld Electrodynamics
Daniel Tennant, Dr. Munoz
I will show some novel features of Born-Infeld electrodynamics. It has been shown that in the context of nonlinear electrodynamics that the concept of the vacuum as an independent non-interacting background has to be abandoned and replaced by a medium with nontrivial electric susceptibility and magnetic permeability. In particular, I will calculate the index of refraction of the vacuum in the presence of a coulomb field. My main result will be to show that spatially varying electromagnetic fields will cause a deflection in the trajectory of electromagnetic radiation passing through a region where the strength of these fields are significant.

3:15 Simultaneous Measurement of the Electron Temperature and Density using Thomson Scattering in the Collective Regime
James Ross, G.R.Tynan, H.A.Baldis, L.Divol,S.H.Glenzer, D.E.Hinkel, MB.Schneider, D.H.Froula
UCSD
The electron temperature and density have been measured locally 200 um outside the laser entrance hole of a hohlraum using multiple-wavelength Thomson scattering. This technique probes fluctuations with two distinct k-vectors thus providing the electron temperature and density. The electron temperature increased to a maximum of 11.9 keV 100ps before the termination of the heater beams and then decreased to 4.6 keV over the next 500ps. The electron density was measured simultaneously and ranged from 1.0 x 10²¹ cm^-3 to 5.2 x 10²⁰ cm^-3. These results show that high-electron temperature conditions are produced in laser-driven hohlraums where the emissivity is an important atomic physics question for studying radiation heated matter. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344 and grant number DE-FG52-2005NA26017 (NLUF). LLNL-ABS-407414.

3:30 Massive Correlated Data Analysis: Predicting the Future with Numbers
Karina Roitman, Yiton Yan
San Francisco State University
Many complex systems today rely more on the collection of data than on theoretical models to predict future values. An algorithm based on the techniques of Principal Component Analysis (PCA) for the prediction of future values in a set of correlated data was implemented. The data was expressed in the form of a matrix of delayed sections (of length m) of each time series and a singular value decomposition was performed on it. The last value of the series was then retrieved, using only some of the singular vectors obtained. The optimization of several of the variables was investigated, most significantly, the number of singular vectors to use in the reconstruction of the data. Using only the leading vector, which exhibits a very low oscillation frequency, gave the best results both in terms of the absolute error in the prediction and in the accuracy in the direction (increase or decrease) of it. However, these predictions didn’t exhibit much oscillatory behavior, which was observed when using several vectors and could be useful for some applications. The effect of varying the row length m, called the embedding dimension, was also studied. The best results were obtained when m=N/4, where N is the total number of data points. Further research could be done on the way to work with several variables simultaneously, on the best strategy to predict more than one value and on a method to predict error bars with each prediction.

3:45 Helicoseir Perturbation Theory
Benjamin Carter
California State University at Long Beach
A variational principle is presented for the equilibrium configurations of a rotating, hanging chain (a helicoseir). A perturbation theory which has been derived from the variational principle is also presented. The perturbation theory uses solutions of the linearized problem as basis functions and describes configurations of small but finite amplitude, which occur at angular velocities slightly greater than those of the linearized problem.

4:00 Research at CSUDH involving applications of x-rays and ultrasound to Biomedical Physics and Biomedical Imaging
Kenneth Ganezer, John Bulman, Tieli Wang, Miodrag Krmar
California State University Dominguez Hills
We will outline our research involving x-rays for Biomedical Imaging in-vivo and radiation therapy using linacs (such as those used in IMRT). We will also describe our studies on new acoustical methods in biomedical imaging, using air-coupled (non-contact) ultrasound to make speed of sound and attenuation measurements and images. In addition this presentation will also outline research at CSUDH in radiation biology, in particular the usage of 2-d proteomic techniques on radiation resistance in radiotherapy We will outline our research involving x-rays for Biomedical Imaging in-vivo and radiation therapy using linacs (such as those used in IMRT). We will also describe our studies on new acoustical methods in biomedical imaging, using air-coupled (non-contact) ultrasound to make speed of sound and attenuation measurements and images. In addition this presentation will also outline research at CSUDH in radiation biology, in particular the usage of 2-d proteomic techniques on radiation resistance in radiotherapy.

11:00-12:30pm,SATURDAY,OCTOBER 18 Session III Room 324&325
11:00 Energetics of Single Mn Defects in Si
Michael Shaughnessy, C.Y. Fong, R. Snow, L. Yang, J. Pask, K. Liu
UC Davis
When a Mn atom is doped into Si, there are three possible sites: the substitutional site (S), the interstitial sites with four (tetrahedral, TI) and six (hexagonal, HI) nearest neighbors, respectively. The TI and substitutional atoms have the same nearest neighbor configuration. To understand the cause of the differing energetics of the three sites, instead of using the popular chemical potential approach, we identify the balance between the electronic and ion-ion contributions as the microscopic origin of the differences among the sites by analyzing their energetics in detail. We provide charge densities to show the strong bonds formed between the substitutional Mn and its nearest neighbors. The Si atoms around the hexagonal and tetrahedral interstitial Mn have saturated bonds so no strong bond is formed in these cases. The hexagonal Mn has shorter bonds with its six nearest neighbors, but more neighbors weakens the bond strength. Including the ion-ion energetics for the three sites allows us to identify the microscopic origin of lowest total free energy for the TI site.

11:15 Computational studies of the chemistry of the Si-rich ß-SiC(100) surface.
Lekh Adhikari, Sean M Casey
University of Nevada, Reno
The chemistry of the Si-rich ß-SiC(100) surface has been studied using density functional theory (DFT) computational methods and small clusters to model the surface reactivity. Results for DFT calculations for the reactions of the cluster models of this surface with adsorbed water, ammonia, and small alcohols and amines will be presented and the energetics compared to the corresponding pathways on the Si(100) surface. In addition to these relatively simple monofunctional molecules, the reactivities of several bi-functional organic molecules have been examined. The results from computations on the reactivities of monofunctional molecules, such as propene and n-propanol, will be compared to results on the reactivity of the corresponding bi-functional molecule, allyl alcohol, in this case. The results show that this computational technique can be used to determine a preference for either oxygen addition or cycloaddition on these surfaces

11:30 The Optimization and Characterization of Magnesium Diboride Thin Films
Brendon Villegas, Dr. Jiyeong Gu
California State University of Long Beach
Magnesium diboride (MgB2) thin films were deposited in an ultra high vacuum onto c-axis oriented Al2O3 substrates at various deposition temperatures followed by in-situ annealing. A study was conducted on the effects of the various growth and annealing parameters on the physical properties of the MgB2 thin films. The substrate temperature was found to be the primary factor in determining the superconducting transitional temperature (Tc), while annealing plays a secondary role. Thin films deposited at substrate temperatures above 180 oC lacked the superconducting transition due to the low Mg sticking coefficient at elevated substrate temperatures. Low deposition temperatures did not produce enough MgB2 phase to experience a transition. The 3D images of surface structures showed higher Tc films displaying a smoother surface and well defined grains, while lower Tc samples lacked these well defined grains.

11:45 Pyridine Intercalation XRD Study, of Bi2Sr2Can-1CunOy High Temperature Superconducting Crystals from Tbilisi, Georgia.
Daniel Loy, J.V.Acrivos ,J. Chidvinadze
San Jose State University
The Bi-Sr-Ca-Cu-O (BISCO:2,2,n-1,n) system is one of the most promising materials for the technical application of high-temperature superconductivity (HTSC). Due to their layered crystal structure, and anisotropy, the HTSC are susceptible to many different types of phase transitions. BISCO is characterized by a 0.3nm per layer structure where an increase in the number of layers from 10 for (2201) to 14 for (2212) to 18 for (2223) which increases the superconducting transition temperature from 10 to 85 to 110K [1]. This suggests that there may be a relation between the c-axis increase and Tc in this system. However, intercalation of pyridine increases the c-axis of BISCO:2212 without changing Tc [2]. We have investigated a Bi-Pb-Sr-Ca-Cu-O, BISCO with 15%Pb substitution for Bi (sample #2) by XRD at SSRL BL:2-1 at room temperature with the purpose of determining its structure before and after intercalation with pyridine. This system is characterized by Tc=107K, and remains superconductive at temperatures where thermal fluctuations play a significant role because their energy is comparable to that of Abrikosov vortices, elastic and pinning energies [3], which are prerequisites for such phase transitions. On exposure to pyridine we measured an increase in the c-axis of 0.3nm in sample#2 which is characterized by equal amounts of BISCO:2212 and 2223 layer structure. Scants at D(t), during recrystallization after pyridine intercalation, of 2223 reviled a resettling and sharpening of the HKL oriented [0,0,8] peak.

12:00 MaxEnt-µSR Study of GdBCO: Search for Low Fields of Predicted Loop Currents in the Cuprate Pseudogap Phase
T. Songatikamas, Janice Wong, H. Ngo, M. Kato, C. Boekema
San Jose State University
Loop currents in the CuO2 planes are predicted to generate magnetic fields in the pseudogap phase of cuprate superconductors. [1] To search for these roughly 40-Oe fields, we apply Maximum Entropy (ME) [2] to transform zero-field (ZF) µSR data of underdoped (Tc = 81 K) and optimal doped (Tc = 93 K) GdBCO. [3,4] We observe hints of a weak 0.3-MHz signal consistent with Varma‚s prediction. [1] The temperature dependence of this frequency signal is as expected for internal fields and is consistent with reported missing fractions [3] and with anomalous polar-Kerr behavior in YBCO. [5] To confirm the existence of these low fields, we must remove the overwhelming 0-MHz signal from the ZFµSR time series using curve fitting before ME transformation. Using µSR-simulation data, we attempt to substantiate the ME-Burg results of our low-frequency analysis, and to validate the existence of these magnetic fields. Analysis of transverse-field (TF) µSR data recorded at (1 kOe, RT) and (100 Oe, 120 and 200 K) has been performed. [4] These TF-µSR results confirm the two Balmer muon-probe sites [3] in GdBCO. These Balmer µ+ sites are relatively far away from the CuO2 planes, and thus will hardly affect any potential loop currents. Proving the existence of these loop currents is crucial to a better understanding of the cuprate pseudogap phase. Research is supported by REU-NSF, DOE @ LANL, WiSE @ SJSU, SJSU Provost Carmen Sigler and Dean Belle Wei, SJSU College of Engineering. We thank Robert Norris for assisting in the initial analysis. [1] M.E. Simon and C.M. Varma, Phys Rev Lett 89 (2002) 247003; C.M. Varma, Phys Rev Lett 83 (1999) 3538. [2] J.C. Lee et al, J Appl Phys 95 (2004) 6906; S. Alves et al, Phys Rev Rapid Comm B49 (1994) 12396. [3] W.K. Dawson et al, J Appl Phys 64 (1988) 5809. [4] J. Wong et al, Bull APS Mar08, K1.00009. [5] J. Xia et al, Phys Rev Lett 100 (2008) 127002.

11:00-12:30pm,SATURDAY,OCTOBER 18 Session III Room 326&327
11:00 SESAME - A Third Generation Synchrotron Light Source for the Middle East
Hamid Javadi, Herman Winick (SLAC/SSRL), Zahid Hussain (LBNL/ALS)
Jet Propulsion Laboratory
Developed under the auspices of UNESCO & modeled on CERN, SESAME (Synchrotron-light for Experimental Science & Applications in the Middle East) is a major international research centre in the Middle East, promoting peace & understanding through scientific cooperation. As its centrepiece is a synchrotron light source originating from BESSY I, a gift by Germany. The upgraded machine, a 2.5 GeV 3rd Generation Light Source (133m circumference, 26nm-rad emittance & 12 places for insertion devices), will provide light from infra-red to hard X-rays for a wide range of studies, including regional biomedical & environmental issues. SESAME offers excellent opportunities to train local scientists & attract those working abroad to return. As of Sept. 2008 SESAME Council Members are Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority, & Turkey. Negotiations are underway with Iraq & more are expected to join. Members provide the annual operating budget. The facility is located in Allaan, Jordan, 30km North-West of Amman. Jordan provided the site & the recently completed building. Plans for initial beam lines include MAD Protein Crystallography, SAXS/WAXS for Polymers & Proteins, Powder Diffraction for Material science, UV/VUV/SXR Photoelectron & Photoabsporption Spectroscopy, EXAFS & IR Spectroscopy. Pakistan is building a soft x-ray beamline. Other Council Members are expected to do the same. Complete beamlines are provided by the Daresbury SRS, the Swiss Light Source, & LURE in France, plus beamline equipment from US labs. Additional funds for components of the new ring & beamlines are sought from the EU, US, & other sources. A training program for beamlines, accelerator technology, & applications is underway, funded by IAEA, US/DOE & other sources. A Director, Administrative Director, Scientific Director & Technical Director are on board. An accelerator group has finalized the design of the facility. Four Advisory Committees work with the staff on the technical design, beam lines, training & scientific programs. A “soft” inauguration, marking building completion & staff occupancy, is scheduled for Nov. 3, 2008, & first light in 2011. See www.sesame.org.jo

11:15 Collider Signals of Maximal Flavor Violation: Same-Sign Leptons from Same-Sign Tops at the Tevatron
Felix Yu, Shaouly Bar-Shalom, Arvind Rajaraman, Daniel Whiteson, CDF Collaboration
UC Irvine
I discuss and present experimental data on models of maximal flavor violation (MxFV). These models predict the existence of one new scalar doublet which mediates large flavor-changing transitions among the quarks, while the flavor-conserving coupling is close to zero. Such MxFV models satisfy all experimental constraints on quark flavor mixing. Moreover, MxFV models result in a striking signal of same-sign leptons from same-sign tops. I conclude with the results of a study of 2 fb$^{-1}$ of CDF II detector data of $p \overline{p}$ collisions.

11:30 Testing a luminosity detector for the BRAN project at the LHC
Johannes Stiller, LUMI Team
Lawrence Berkeley National Laboratory
We are building a detector, called BRAN that will be used to monitor the luminosity of the LHC. The BRAN is a pressurized gas ionization chamber segmented into four independently working quadrants each consisting of six gaps. Using 350 GeV protons at CERN‚s SPS, the characteristics of its final design have been tested. We have tested the BRAN‚s performance versus gas pressure, absorber thickness, and voltage, and we have compared these measurements to results from Monte Carlo simulations. Two detectors, surrounding each of the interactions points at ATLAS and CMS, are going to be set up at CERN‚s LHC. Recently two of those were installed. These devices will measure the bunch-by-bunch luminosity and crossing angle of the beam at these locations. The recent tests, simulations, and the current status of the detector will be presented.

11:45 Neutron-Antineutron Oscillation Research
Mark Lohmann, Dr. Kenneth Ganezer my research advsior.
California State University, Dominguez Hills
My presentation is about my contributions to the research on neutron-antineutron oscillations being conducted by Dr. Kenneth Ganezer (my research advisor), other faculty, and other undergraduate students at California State University, Dominguez Hills involving the Super Kamiokande nucleon decay and neutrino experiment and collaboration. I first plan to give a brief description of the neutron-antineutron research. I then plan to talk about the parts of the research that I worked on which include: analyzing the total initial and final linear momentum of the interacting particles after propagation through the residual nucleus for the different possible modes of annihilation making sure that the linear momentum is conserved at all stages of the oscillation, annihilation, and both pre and post nuclear propagation processes, helping to make the program keep track of the total initial and final charge of the interacting particles to make sure that charge was being conserved in all of the interactions, and, what I am currently working on, making the Japanese version of the neutron-antineutron annihilation Monte Carlo simulation keep track of the interactions on an event by event basis in the same way as the American version of the program is currently doing to provide a more accurate method of estimating the uncertainties our oscillation limits due to the choice of nuclear propagation model.

12:00 Searches for neutron-antineutron oscillations at Super-Kamiokande with tie-ins to other research at Super-K and to DUSEL
Kenneth Ganezer, James E. Hill , William E. Keig, Mark Lohmann, Laurene Barrie, and Super-K
California State University Dominguez Hills
We will outline recent research at the Super-Kamiokande Observatory involving the CSUDH subgroup of the Super-Kamiokande collaboration. This research includes our collaborative efforts on searches for neutron-antineutron oscillations that recently obtained lifetime and oscillation time lower limits of 1.97 x 10³² years and 2.49 x 108 seconds for neutrons bound in 16O and free neutrons, respectively. These new limits may help to constrain R-L symmetric theories of Grand Unification. We will briefly mention our collaborative plans for a free neutron oscillation experiment at DUSEL, the Deep Underground Science and Engineering Laboratory at the Homestake Mine in Lead, South Dakota, and studies of neutrino physics and nucleon decay at Super-Kamiokande.

12:15 Do Mirrors for Gravitational Radiation Exist?
Stephen Minter, Raymond Chiao, Kirk Wegter-McNelly
University of California, Merced
It has been experimentally verified that a thin, superconducting film can specularly reflect electromagnetic radiation. It may be possible for gravitational radiation to be reflected from the surface of a Type I superconducting thin film as well. In the limits of weak gravitational fields and slowly-moving matter, Einstein's field equations reduce to a set of Maxwell-like equations. This model, and the behavior of macroscopically coherent quantum charge and mass carriers in the presence of time-varying gravitational fields, may give rise to specular reflection of gravitational radiation.

1:30-3:00pm,SATURDAY,OCTOBER 18 Session IV Room 324&325
1:30 Field (Direction) Dependence of AF Magnetism in YBCO Vortex States: a Detailed MaxEnt-µSR Study
Michael Browne, R. Kwok, C Boekema
San Jose State University
Muon-spin-resonance (µSR) data of YBa2Cu3O7 (YBCO) vortex states are analyzed to determine in detail the field dependence of observed antiferromagnetism (AF). YBCO vortex states of different grain sizes are investigated at low magnetic fields well below the critical temperature. Field distributions are obtained from µSR data [1] using Maximum-Entropy (ME) analysis at a higher frequency resolution than performed in [2]. We will fit the grain-boundary / epoxy signal in time space with Gaussian-relaxed cosine functions and then subtract this signal from the time histograms before applying the ME transformation. The vortex signal in the remaining field distribution is best fitted by a Lorentzian, indicating AF in and near the vortex cores. The field dependence of the YBCO AF Lorentzian width is approximately linear [3] and consistent with theoretical expectations such as from the SO(5) theory. [4] ME-µSR analysis of c-axis-oriented YBCO vortex data indicates a field-direction dependence that is in contrast to previous curve-fitting results. [1] We discuss the relevance of an AF presence in YBCO vortex states in support of theories predicting a magnetic origin of cuprate superconductivity. Research is supported by NSF-REU, DOE-LANL and WiSE at SJSU. We thank C Teichgraeber for the initial ME-Burg analysis. [1] Lichti et al, Hpf Int's 63 (1990) 73 [2] Boekema C et al, 2008 J. Phys.: Conf. Ser. (25th Int Conf Low Temp Physics, Amsterdam, August 2008, LT25), in press [3] Boekema C et al, 2007 Physica C 460-462 1255 [4] Zhang S-C 1997 Science 275 1089 Arovas D P et al 1997 Phys Rev Letter 79 2871 Chen H-D et al 2004 Phys Rev B 70 024516 and references therein.

1:45 Control of Magnetization Reversal in Co/Pt Networks with Perpendicular Anisotropy
Nasim Eibagi, Randy K. Dumas, Kai Liu M, Tofizur Rahman, Nazmun N Shams, Yun-Chung Wu, Ch
UC Davis
Magnetic nanostructures with perpendicular anisotropy have been extensively studied for their interesting physical properties and importance in perpendicular magnetic recording applications. We demonstrate a simple method to tailor the magnetization reversal mechanisms of [Co (0.5nm)/Pt (2nm)]5 multilayers by depositing them onto nanoporous anodized alumina templates (AAO) with various aspect ratios, A = pore depth / pore diameter. Reversal mechanisms are studied using a First Order Reversal Curve (FORC) method [1]. This technique involves measuring ~102 reversal curves that fill the interior of the major hysteresis loop. From this family of FORCs a mixed second-order derivative of the magnetization then captures the irreversible component of the reversal. The FORC technique not only generates a useful fingerprint of the reversal mechanism but also provides valuable quantitative information. For a thin film reference sample the FORC distribution clearly shows features consistent with nucleation and annihilation of the relatively unimpeded motion of domain walls. For the composite (Co/Pt)/AAO films with large A the FORC diagrams show modifications consistent with strong domain-wall pinning induced by the pores. Finally, for small A the FORC diagrams reveal a fundamentally different reversal mechanism consistent with a Stoner-Wohlfarth like rotation of the magnetization. As more material is deposited inside the pores and the spacing between pores approaches the domain wall width the Co/Pt multilayers essentially become an assembly of isolated magnetic islands separated by AAO walls. 1. Davies et al. Phys. Rev. B 70, 224434 (2004); Dumas et al. Phys. Rev. B, 75, 134405 (2007).*Work at UCD supported by CITRIS.

2:00 Static and Time-Resolved Photoluminescence Study of coupled colloidal QDs on Microstructured Thermoplastic Substrates
Somnath Ghosh, C. G. L. Ferri, B. Edmunds, M. Khine and S. Ghosh
School of Natural Sciences, University of California, Merced, CA 95344, US
We report a study of the dynamics of charge-carriers in cadmium selenide (CdSe) quantum dots (QDs) spin-coated on biaxially microstructured and metal coated substrates. These substrates are prepared by sputter coating 30 nm of Au-Pd metallic alloy on pre-stressed thermoplastic templates. After heat treatment in a baking chamber, both the thermoplastic and the metal coating shrink by almost 50% but due to different stiffnesses, the metal coating buckles to developed channels and wrinkles in a hierarchy of self-organized length scales, ranging from tens of microns to hundreds of nanometers. Two-dimensional, spatially-resolved maps of the photoluminescence (PL) of CDSe QDs spin-coated on to these substrates show varying spectral red-shifts of the peak emission, in comparison to the intrinsic emission wavelength of the QDs in solution. The red-shifted emission is an evidence of facile energy transfer by inter-dot electronic coupling between QDs brought about by spatial aggregation due to the topographical features in the substrates. On the other hand, no red-shift of emission wavelength is seen in PL from flat thin-film substrates which lack any such spatial features. A study of charge-carrier dynamics in the form of time-resolved PL demonstrates reduced recombination times on account of the coupling between the QDs. The reduced lifetimes as a function of peak emission wavelength, as well as the variation in spectral alteration with different QD sizes (2⁶ nm) further allow us to understand the nature of coupling and the rates of energy transfer in these systems. This work was supported by Shrink Inc., CA.

2:15 Raman spectrum of 1,3,5,7-cyclooctatetraene as a function of pressure
Edward Romano, Sergey Tkachev, Michael Pravica, Eunja Kim, Philippe Weck
University of Nevada Las Vegas
Studying molecular solids at high pressures presents great analytical challenges. Here, we have investigated changes in the vibrational spectra of liquid and solid 1,3,5,7-cyclooctatetraene (COT), by examining changes in its Raman spectra (in the 100-1800 cm-1 and 2900-3200 cm-1 regions) with pressure, and have compared our data to theoretical calculations. The pressures were generated by a diamond anvil cell, in the gigapascal (GPa) range, and the maximum pressure achieved for the experiment is ~16 GPa. Three phase transitions were observed within the studied pressure range, the last phase being an unknown substance that had a large luminescence spectrum suggesting novel chemistry under extreme conditions.

2:30 I-V curve of Randomly Oriented ZnO Nanowires
Ulises Urbina, Pei-Chun Ho, Daqing Zhang
California State University, Fresno
ZnO nanowires have applications in solar cell technology, thin film gas sensors, lasers, and LED technology. The band-gap energies for ZnO nanowires are different as compared to the bulk material. ZnO is a wide band-gap semiconducting material of 3.37eV, which is in the optical range for photons. A mat of ZnO nanowires were produced in a Fresno State campus laboratory. The I-V curve was acquired at room temperature by standard 4-wire DC measurement technique in the ambient environment, as well as, in vacuum and at low temperatures.

2:45 Synthesis and Characterization of Gd Nanoparticles
Dulce Romero, Pei-Chun Ho, Saeed Attar
California State University, Fresno
Due to the reduced dimensionality, nano-sized materials have physical properties significantly different from the bulk material. The nano-sized materials have great potential for technical applications, such as, magnetic information storage, imaging, medical devices, and magnetic refrigeration. In this report, we will present the preliminary results on the growth and characterization of rare-earth Gd nanoparticles synthesized by the inverse micelle method [1]. These results will be compared to the bulk properties of Gd [2,3], as well as the properties of existing metallic nanoparticles, such as, superparamagnetic behavior, enhanced magnetization, and self-organization [4-6]. [1] X.M. Lin, et al. Langmuir. 14, 7140 (1998). [2] H.E. Nigh, et al. Phys. Rev. 132, 3 (1963). [3] Z.C. Yan, et al. Phys. Rev. B. 67, 054403 (2003). [4] D.C. Douglass, et al. Phys. Rev. B. 47, 19 (1993). [5] J.P. Chen, et al. Phys. Rev. B. 51, 11527 (1995). [6] C. Petit, et al. Advanced Materials. 10, 259 (1998).

1:30-3:00pm,SATURDAY,OCTOBER 18 Session IV Room 326&327
1:30 Variable-temperature Raman spectro-microscopy for a comprehensive analysis of the phase transitions and conformational order in PEGylated lipids
Rajan Bista, e, it would be nice if you could schedule my talk accordingly for Saturday morning. Thank you.
University of Nevada, Reno
The investigation of phase transitions and associated changes in the conformational order of lipids is of importance in various research areas dealing with phenomena such as the formation and fusion of vesicles, trans-membrane diffusion and membrane interactions with drugs and proteins. In this article, we have focused on the study of thermotropic phase behaviors and associated changes in the conformational order of two newly developed synthetic PEGylated lipids trademarked as QuSomesTM. In contrast to conventional phospholipids, this new kind of lipid forms liposomes spontaneously upon hydration, without the supply of external activation energy. Variable-temperature Raman spectro-microscopy has been employed in order to plot the transition temperature profiles showing the phase behavior of these new lipids composed of 1,2-dimyristoyl-rac-glycerol-3-dodecaethylene glycol (GDM-12) and 1,2-distearoyl-rac-glycerol-3-triicosaethylene glycol (GDS-23). Furthermore, several spectral indicators were calculated and correlated which allowed for the deduction of various aspects of molecular structure as well as intramolecular motion and intermolecular interactions. To confirm the observations, differential scanning calorimetry (DSC) was applied and revealed a good agreement with the Raman spectroscopy results. Finally, this information may find application in various studies including the development of lipid based novel substances and drug delivery systems.

1:45 Flow Optimization and Large-Scale Structures in Turbulence
Aaron Freeman, Haris Catrakis
University of California, Irvine
This research focuses on active flow control for suppression and regularization of turbulent coherent structures. Unforced turbulent shear flows naturally exhibit large-scale organized structures also known as coherent structures. With imposed forcing, the possibilities arise for suppression of coherent structures or regularization of these structures. This is useful because suppression can be utilized in problems that would otherwise have dominant detrimental effects from coherent structures and because regularization can be utilized to reduce the irregularity and therefore unpredictability of turbulence. We demonstrate evidence of suppression and regularization in separated turbulent shear layers in air using forcing based on dielectric barrier discharge plasma actuators.

2:00 Multiscale Analysis and Imaging of Turbulence
Jennifer Shockro, Haris Catrakis
University of California, Irvine
This research focuses on multiscale analysis and imaging of turbulent scalar fields and interfaces. The multiscale-minima meshless method is explored which is a theoretical and computational approach to fractal dimensions with broad applicability. The method is demonstrated using experimental images of turbulent jet scalar fields. The theory of this method is based on the analytical relation between the shortest-distance probability density function and the generalized fractal dimension as a function of scale. The shortest distance refers to the distance between a random point location and the nearest part of the object, where the point location is chosen within a reference boundary containing the multiscale object of interest such as a turbulent scalar interface. We utilize the method with analytical examples, computational tests, and experimental images of turbulent jet scalar fields.

2:15 Direct Numerical Simulations of Forced Three- Dimensional Turbulence
Ryan Sokolowski, Adam Wachtor, Haris Catrakis
University of California, Irvine
This research focuses on computational studies of turbulence using direct numerical simulations. We utilize the pseudospectral method to compute forced three-dimensional turbulence in a box with periodic boundary conditions. Our computational data are analyzed with emphasis on the relation between spectral and fractal aspects. The multiscale temporal dynamics and spatial structure of the vorticity and velocity are explored in physical space and in Fourier space. Our approach enables an examination of how the flow varies as a function of scale and provides a testbed for exploring variational principles of turbulence.

2:30 Large-Eddy Simulations of Turbulence and Urban Contaminant Dispersion
Adam Wachtor, Fernando F. Grinstein, Haris J. Catrakis
University of California, Irvine
Simulations of wind flow in urban areas can offer insight and knowledge about the flow physics that can not be found through experiments. Such urban flows are highly complex and consist of a wide range of multiscale phenomena. Monotone Integrated Large Eddy Simulations (MILES) is currently a promising method to obtain reasonable results of urban flows as it is able to resolve large scale features and relies on inherent numerical dissipation to model energy transfer from the resolved scales to the subgrid scales. NRL's FAST3D-CT model based on MILES is used to simulate scalar contaminant transport in an urban geometry. The knowledge gained through such simulations can be critical to city, state, and federal officials for risk management. We present a brief study of the effects that grid resolution and boundary conditions have on the transport of a scalar contaminant in a specified urban geometry. (LA-UR-08-06324)

2:45 Sensitivity optimization of an atomic magnetometer based on nonlinear optical rotation
Srikanth Guttikonda, L. Rene Jacome, Eric J. Bahr, LokFai Chan, and D. F. Jackson Kimball
CSU East Bay, Dept. of Physics
We have constructed an atomic magnetometer based on the technique of nonlinear magneto-optical rotation with frequency modulated light (FM NMOR). The magnetometer will be used in a new search for an equivalence-principle violating interaction of atomic spins with the earth's gravitational field. We report on a systematic optimization of the magnetometric sensitivity of FM NMOR for the rubidium D2 line. The optimum projected shot-noise-limited sensitivity of the magnetometer is better than 100 pG (10 fT) in 1 second of integration.