isis poster session winter 2007

photo gallery (new!)

 poster presentations  ::  presenter instructions

December 7, 2007

4:00 - 6:00 p.m.

Location:  1201 Natural Sciences II

The Winter 2007 ISIS Poster Session on Friday was a huge success.  All posters were greatly appreciated. 
Thank you, presenters, for participating in the event!

Congratulations to our Poster Award Winners!  Judges Ruqian Wu, Ken Janda and Kieron Burke,
had the tough job of selecting winners from a variety of great posters.  (titles and abstracts below)

:; Galina Kerenskaya
:: Bucky Khalap
:: Aleix Garcia
:: Raffaela D'Auria


Also,  we would like to thank the Reginald Penner group and the John Hemminger group for their
assistance with set up and clean-up.

We enjoyed seeing you there and we look forward to the next ISIS Poster Session in June!


event details:

ISIS (the Institute of Surface and Interface Science) is one of 16 Organized Research Units (ORUs)
on the University of California, Irvine (UCI) campus. Through collaborative projects it brings together
faculty and researchers in:

:: Chemistry
:: Physics
:: Developmental and Cell Biology
:: Chemical Engineering and Materials Science
:: INRF
:: Electrical Engineering and Computer Science

This poster session is informal in nature, and it provides an opportunity to learn about current
ISIS member research projects.  This is also a social occasion for ISIS members to get together
to interact - students, postdocs and other group members are especially welcome! 

Posters for the session can be composed of papers presented at recent conferences, or
just a few figures interspersed with brief explanatory prose.

For additional information, please contact:

Diane Stathakis (diane.s@uci.edu).

Instructions
.........................................................................................................................................


::  Locate the card with the poster number that corresponds with the number
    assigned to your poster on the printed program.

::  Attach the number to you poster or poster board.

::  Set up your poster and poster board.

At the end of the poster session, please help with clean-up:

::  Taking down your own poster
::  Collapse your easel and put it into a box
::  Take the easel and the poster board into 1115 NS II, the ISIS Conference room
::  Please help with trash pick up as well if you are able




Poster Presentation Winners
.........................................................................................................................................

Author(s)::	G. Kerenskaya, I. U. Goldschleger, K. C. Janda, and V. A. Apkarian
Department(s)::	Department of Chemistry, UC Irvine
Title::	POLYMORPHISM IN Br2 CLATHRATE HYDRATES
Abstract::	Clathrate hydrates are non-stoichiometric compounds, consisting of guest molecules trapped in a lattice of polyhedral water cages. The resurgence of interest in this fascinating class of solids is in part motivated by the recognition of the vastness of natural deposits of methane hydrates, and their potential global implications with respect to energy and the environment. The structure and composition of bromine clathrate hydrate has been controversial for more than 170 years due to the large variation of its observed stoichiometries. Several different crystal structures were proposed before 1997 when Udachin et al. concluded that Br2 forms only the tetragonal structure. We show polymorphism in Br2 clathrate hydrates by identifying two distinct crystal structures through optical microscopy and resonant Raman spectroscopy on single crystals. The two structures are clearly distinguished by the resonant Raman spectra of the enclathrated Br2, which show long overtone progressions and allow the extraction of accurate vibrational parameters.

Author(s)::	Vaikunth Khalap, Tatyana Sheps, Alexander Kane, Philip G. Collins
Department(s)::	Department of Physics and Astronomy and CaSTL, UC Irvine
Title::	HYDROGEN SENSING PROPERTIES OF PALLADIUM-DECORATED CARBON NANOTUBE CIRCUITS
Abstract::	Sensitive hydrogen gas sensors can be fabricated from carbon nanotube circuits decorated with palladium metal, and we have investigated the responsible physical mechanisms using isolated, single-walled carbon nanotubes (SWCNTs).  A highly sensitive transduction mechanism involves Pd-decorated defect sites, which in both metallic and semiconducting SWNTs results in reversible conductance swings of 100%.  This experiment will study the temporal dynamics and pressure dependence of this mechanism.

Author(s)::	Aleix. G. Güell,2  Megan E.Bourg,1 Wytze E.van der Veer,1 Reginald M. Penner 1*
Department(s)::	1 Department of Chemistry and Institute for Surface and Interface Science, UC Irvine 2 Department of Physical Chemistry, University of Barcelon
Title::	NANOTHERMOCOUPLES SYNTHESIZED BY LITHOGRAPHICALLY PATTERNED NANOWIRE ELECTRODEPOSITION
Abstract::	The thermocouple is one of the most commonly used devices for temperature sensing, due to its simplicity and easy integration into electronics. In this work, the dimensions of the thermocouple has been further reduced respect our previous work [1] to the range from 50 nm to 300 nm by using Lithographically Patterned Nanowire Electrodeposition (LPNE) [2]. This new method, based on photolithographic techniques, allows the synthesis of nanowires with a high control of the nanometric dimensions of their cross section, their position and macroscopic shape, and with an electrically continuous length that can exceed millimeters. All these are important facts for a further industrial application. Three different prototypes have been designed: single cross nanowires, 2D array cross nanowires, and nanowire-thin film. The devices present extremely fast response times (<100 ns), high stability over long cycles of heating-cooling (temperature range from 20ºC to 120ºC), and a stable lineal calibration with time and use. 1. M. E. Bourg; W. E. van der Veer; A. G. Güell and R. M. Penner, Nano Letters, 7, 3208-3213 (2007). 2. E. J. Menke; M. A. Thompson; C. Xiang; L. C. Yang and R. M. Penner, Nature Materials, 5, 914 - 919 (2006). Acknowledgments: A.G.Güell acknowledges The Electrochemical Society for the Edward G. Weston Fellowship 2007.

Author(s)::	Raffaella D'Auria,1 Maria J. Krisch,1 Matthew A. Brown,1 Douglas J. Tobias,1 John C. Hemminger,1 Markus Ammann, 2 Hendrik Bluhm,3 David E. Starr3
Department(s)::	1 AirUCI and University of California at Irvine 2 Paul Scherrer Institute 3 Lawrence Berkeley National Laboratory
Title::	THE EFFECT OF AN ORGANIC SURFACTANT ON THE LIQUID-VAPOR INTERFACE OF AN ELECTROLYTE SOLUTION
Abstract::	Abstract:: The addition of 1-butanol to an aqueous potassium iodide solution modifies the interfacial profile of ions at the liquid - vapor interface.  Our experiments probe atomic composition at the liquid surface with ambient pressure x-ray photoelectron spectroscopy.  Photoelectron kinetic energies are varied to produce a depth profile of the liquid - vapor interface. Surface enhancement of iodide anions, an effect observed in aqueous potassium iodide solution, disappears in the presence of 1-butanol, a surface active alcohol.  Molecular dynamics simulations of butanol in an aqueous electrolyte solution exhibit the same effect.  Radial distribution functions calculated from the simulations show that butanol appears to interact with both the anion and the cation; this is likely to be the basis for the observed changes in the ion distribution in the presence of the organic.  Insight into ion behavior at mixed organic/aqueous liquid surfaces is crucial for understanding the chemistry of atmospheric aerosols, which frequently contain mixtures of water, electrolytes, and organics.

....................................................................................................................................................................

previous events
.........................................................................................................................................

isis year-end poster session 2007

 ::  Award-Winning Presentations  ::

poster presentations  ::  presenter instructions

June 8, 2007

5:00 - 7:00 p.m.

Location:  Frederick Reines Hall Lobby

ISIS (the Institute of Surface and Interface Science) is one of 16 Organized Research Units (ORUs)
on the University of California, Irvine (UCI) campus. Through collaborative projects it brings together
faculty and researchers in:

:: Chemistry
:: Physics
:: Developmental and Cell Biology
:: Chemical Engineering and Materials Science
:: INRF
:: Electrical Engineering and Computer Science

This poster session is informal in nature, and it provides an opportunity to learn about current ISIS
member research projects.  This is also a social occasion for ISIS members to get together to
interact - students, postdocs and other group members are especially welcome! 

Posters for the session can be composed of papers presented at recent conferences, or
just a few figures interspersed with brief explanatory prose.

Please submit abstract and presentation using the ONLINE SUBMISSION FORM:

http://forms5.createforms.com/11061/form_2_1.html

If your abstract exceeds 250 characters, please forward it to Alison Lara  (laraa@uci.edu).

For additional information, please contact:

Anne Taub (annetaub@uci.edu) or Diane Stathakis (diane.s@uci.edu).

....................................................................................................................................................................

instructions
.........................................................................................................................................

Volunteers are needed to assist with easel and poster-board transport and set-up from the Chemistry office to the lobby of FRH. 
Please contact Anne Taub (annetub@uci.edu) if you are availble to volunteer, starting at 4 p.m.

At 4:30 p.m. on Friday, June 8 in the lobby of FRH:

::  Locate the card with the poster number that corresponds with the number assigned to 
    your poster on the printed program.

::  Attach the number to you poster or poster board.

::  Set up your poster and poster board.

PRIZES
Judges: Professors Max Wolfsberg and Alexei A. Maradudin will review the posters.  When they have chosen the three
top posters (two graduate and one undergraduate), they will make an announcement. 

Winners will be awarded with a certificate and a $50 UCI Bookstore certificate.
PRIZE WINNERS: #11 (Ning Wang), #14 (Megan Bourg) and #16 (Eric Kalman).  Congratulations to these three prize winners!

At the end of the poster session, please help with clean:
::  Taking down your own poster
::  Collapse your easel and put it into a box
::  Take the easel and the poster board into 1115 NS II, the ISIS Conference room
::  Please help with trash pick up as well if you are able




Award-Winning Presentations
.........................................................................................................................................

Congratulations to the three winners of the June ISIS poster session!

Poster Judges: 
Professor Max Wolfsberg, Department of Chemistry
Professor Alexei  Maradudin, Department of Physics and AStronomy

$50 Gift Certificate Prize Winners (in the order listed, not as first, second, third, etc.)

# 11.  Eugene Y. Song, Rong W. Maoj, Ning Wang, Prof. Chen S. Tsai1
Shirley C. Tsai2   
1 Dept. of Electrical Engineering and Computer Science
2 Dept. of Chemical Engineering, Calif. State Univ., Long Beach   
   
Title - MHz Ultrasonic Nozzles with Applications to Nano/Bio/Materials Technology   
    .........................................................................................................................................
   
# 14 Megan Bourg, Prof. Reginald M. Penner
Department of Chemistry
   
Title -  Towards Nanowire-Based Thermocouples   
    .........................................................................................................................................

# 16 E. Kalman, K. Healy, Prof. Z. Siwy
Department of Physics and Astronomy

Title - Tuning of Ion Current Rectification by Signal Mixing
   
.........................................................................................................................................

Special thanks to Professor Wolfsberg and Professor Maradudin for their hard work in selecting
three among the 25 as "winners." I am sure this was a difficult task.

Also special thanks to the Collins Group for their assitance with set-up and clean-up - the help
was much appreciated.

Soon we will have photos of the event and of the winners posted on the ISIS website maintained
by Alison Lara of the Physics Department. Thanks to Alison for her excellent job in this area. 
Here is the Website address:

http://www.physics.uci.edu/~isis/





Poster Presentations
.........................................................................................................................................

1
Author(s)::	Aniketa Shinde (email: ashinde@uci.edu)
Affiliation(s)::	Physics & Astronomy
Title::	Fabrication and Optimization of Ordered Assemblies of Monodisperse Noble Metal Nanostructures: a platform for understanding nanoscale catalysts
Abstract::	Noble metal (Au, Pt) nanostructures have demonstrated higher performance in catalytic properties than their bulk counterparts, exhibiting higher activity and turnover frequency for reactions such as CO oxidation and ethylene hydrogenation.  We employ a unique fabrication process that uses self assembled rare earth disilicide (RESi2) nanowires as templates on stepped silicon surfaces to produce ordered parallel arrays of size-controlled platinum and gold nanowires and nanoparticles for the purpose of studying size, shape and materials dependence of catalytic properties.  After the template is fabricated, noble metal is deposited and preferentially aggregates on the RESi2 nanowire surface. Reactive ion etch results in noble metal nanoparticles or nanowires depending on coverage.  Our nanoparticles show a narrow size distribution comparable to solution fabricated nanoparticles.  Using the Vienna ab initio Simulation Package studies are being performed to understand self-assembly mechanisms for future system optimization.

2
Author(s)::	Alex Kane (email: akane@uci.edu)
Affiliation(s)::	Physics and Astronomy
Title::	High Temperature Conductivity and Reactivity of Carbon Nanotube electronic Circuits
Abstract::	At high temperatures carbon nanotubes begin to react with their environment. We have built an apparatus that provides continuous four probe electrical characterization of the nanotubes from room temperature to 1500 K in an ultrahigh vacuum system.

3
Author(s)::	Dora Guzmán (email: dguzman@uci.edu)
Affiliation(s)::	Department of Chemistry
Title::	Investigation of Mechanically Stable Protein Domains for Use in Advanced Biomaterials
Abstract::	TBN

4
Author(s)::	Vaikunth Khalap, Alexander Kane, Prof. Phil Collins (email: vkhalap@uci.edu)
Affiliation(s)::	Physics and Astronomy
Title::	Chemoresistance of carbon nanotube circuits incorporating electrochemically-decorated defects
Abstract::	We investigate SWNT devices with single point functionalizations. Standard fabrication techniques are supplemented by an electrochemical point-oxidation process that creates insulating defects into pristine SWNTs.  Selective electrochemistry subsequently deposits metal onto the insulating site(s) and restores the device conductivity.  The resulting circuits inherit the chemical sensitivity of the metal deposits.

5
Author(s)::	L.C. Yang, P.Y. Tam, B.J.  Murray, T. M. McIntire, Cathie M. Overstreet, G.A. Weiss, Prof. R.M. Penner (email: lcyang@uci.edu)
Affiliation(s)::	Department of Chemistry
Title::	Virus Electrodes for Universal Biodetection
Abstract::	The development of label-free biosensors for key biomolecules is an objective that is shared by many research groups worldwide.  We present an approach involving the electrochemical detection of biomolecules binding to electrode surfaces on which an engineered bacteriophage, M13, has been covalently attached. This bacteriophage has - on its surface - polypeptide receptors that form the basis for molecular recognition.  These phage particles are prepared using the techniques of phage display.     We describe the preparation of the biosensor surface, the optimization of the electrochemical impedance measurement, and the results of our first experiments that involve the detection of antibodies that are recognized and bound by the immobilized phage particles, and “control” antibodies that are not recognized.  The response of this biosensor to the prostate cancer marker, PMSA, is also reported. In all cases, the observed impedance responses are “benchmarked” against the response of a quartz crystal microbalance, on which the biosensor is constructed.

6
Author(s)::	Yuan Xingao Gong, Prof. Ruqian Wu (email: uand@uci.edu)
Affiliation(s)::	Physics and Astronomy
Title::	Origin of high activity and selectivity of PdAu(001) bimetallic surfaces toward vinyl acetate synthesis
Abstract::	We perform systematic density functional studies to elucidate the mechanism of vinyl acetate synthesis on Pd/Au(001). Atomic geometries, activation energies and reaction energies are determined for three separate reaction stages: coupling of ethylene and acetate; â-H elimination; and vinyl acetate desorption. Significantly, we find that Pd „monomer‰ pair is much more robust in all three reaction stages than large Pd ensembles such as Pd monolayer, mainly due to high mobility of reactants on surrounding Au sites. The remarkable high activity and selectivity of vinyl acetate reaction on PdAu bimetallic surfaces observed by Goodman et al. are exclusively attributed to the ensemble effects.

7
Author(s)::	T. A. Leskova1, Prof. A. A. Maradudin1, E. R. Mendez2 (email: tleskova@uci.edu)
Affiliation(s)::	1Physics and Astronomy / Institute for Surface and Interface Science, UCI 2Division de Fisica Aplicada, Centro de Investigacion y de Educacion Superior de Ensenada,  Km. 107 carretera Tijuana-Ensenada, Ensenada, B.C.  22800, Mexico
Title::	TBN
Abstract::	We  show that it is possible to design a  randomly rough perfectly conducting surface that, when illuminated at normal incidence by a beam with a specified intensity profile in the plane of scattering transforms this beam into a scattered beam with a different specified intensity profile in the far field.

8
Author(s)::	Wei Luo1, Ping Chu2, Prof. Douglas L. Mills2, Prof. Reginald M. Penner1, Prof. John C. Hemminger1* (email: wluo1@uci.edu)
Affiliation(s)::	1Department of Chemistry / Institute for Surface and Interface Science 2Department of Physics and Astronomy / Institute of Surface and Interface Science
Title::	Polarization-Dependent Surface Enhanced Raman Scattering from Silver Nanoparticle Arrays
Abstract::	One specially promising method to design Surface Enhanced Raman Scattering (SERS) substrates is to fabricate silver nanoparticle arrays with nanoscale gaps that can carry strong and localized surface plasmon resonances. Studies have revealed that dramatic SERS phenomena require interparticle spacings to be around 10 nm or less which is hard to achieve with current fabrication technologies. We present the straightforward fabrication of ordered spherical silver nanoparticle arrays with gaps less than 10 nm on Highly Oriented Pyrolytic Graphite (HOPG). Physical Vapor Deposition (PVD) of silver on HOPG under controlled experimental conditions results in the self-assembly of rows of silver nanoparticles. Straight rows of particles are obtained that extend over distances as large as 100 microns. Arrays of rows of particles are parallel over similar distances. Since these 2-dimentional particle arrays are organized over 100’s of microns they are easily addressed in conventional optical experiments. Using thiophenol adsorbed on the silver particles as probe molecules, highly polarization-dependent enhanced Raman scattering has been observed form these particle arrays. When light is polarized along the axis of the nanoparticle arrays, the enhanced Raman spectra are much stronger than when light is polarized perpendicular to the axis of the nanoparticle arrays. Theoretical calculations of the electromagnetic response of the interacting nanoparticles to a light field will also be presented. Ongoing research with these arrays includes a number of different studies. Among these is the use of the particle arrays as a collection of “nano-electrodes”. For example, electrodeposition of semiconductors on the silver nano-arrays has been accomplished with the subsequent observation of enhanced photo luminescence.

9
Author(s)::	Matthew Aggleton (email: maggleton@gmail.com)
Affiliation(s)::	Physics and Astronomy
Title::	Low temperature friction of diamond films
Abstract::	Diamond, being a very strong and wear resistant material, has been of increasing interest ever since the development of artificial  olycrystalline films.  In order to further our understanding of the friction properties of diamond, the coefficient of kinetic friction (COF) of polycrystalline diamond films with natural diamond counterfaces has been measured over a wide range of cryogenic  temperatures under ultra-high vacuum.  A significant difference has been seen between microcrystalline diamond films (MCD) with very low hydrogen content and ultra-nanocrystalline diamond films (UNCD) with  high hydrogen content.  The MCD has a high COF (.6) over all temperatures from 8K to 300K.  The UNCD, on the other hand, displays notable and repeatable changes in COF with temperature, most changes occuring between 125K and 350K.  In addition, studies were performed to observe wear-in rates at constant temperatures.

10
Author(s)::	Eli Van Cleve (email: vancleve@uci.edu)
Affiliation(s)::	Physics and Astronomy
Title::	Cryogenic Pulsed Laser Deposition and Helium Adsorption on Lithium Substrates
Abstract::	The helium adsorption and wetting properties of alkali metals have been studied for years with the focus on cesium and rubidium.  Helium wetting properties of alkali metals is of interest because their interactions with helium are the weakest in nature.  Until now it was not possible to make cryogenic lithium films because of its high melting temperature and therefore it was not possible to study the helium adsorption and wetting properties of lithium.  Using newly developed cryogenic pulsed laser deposition system lithium films were grown at 4K onto a quartz crystal microbalance (QCM).  The helium adsorption properties of lithium were studied by running helium isotherms between 1.45K and 2.5K.  No solid like layers of helium were observed on the lithium films and the superfluid transition was observed to occur at a lower pressure but the same helium liquid thickness as gold.  By measuring the low coverage slope of the isotherms the ground state of helium bound to lithium was found to be -13.65K.

11	Prize Winner!
Author(s)::	Eugene Y. Song, Rong W. Maoj, Ning Wang, Prof. Chen S. Tsai1 Shirley C. Tsai 2 (email: cstsai@uci.edu)
Affiliation(s)::	1Dept. of Electrical Engineering and Computer Science 2Dept. of Chemical Engineering, Calif. State Univ., Long Beach
Title::	MHz Ultrasonic Nozzles with Applications to Nano/Bio/Materials Technology
Abstract::	This paper reports realization of 1MHz ultrasonic nozzles using Si-based micro-electro-mechanical system (MEMS) technology for production of 5 mm-diameter monodisperse droplets with applications to nanoparticles synthesis, microelectronics processing, and pulmonary drug delivery. ____________ *Sponsors:    National Institute of Health (NIH); UC Discovery Program

12
Author(s)::	Gang Qiu, Masatoshi M. Kobayashi, Prof. Chen S. Tsai (email: gangq@uci.edu)
Affiliation(s)::	Electrical Engineering & Computer Science
Title::	Enhanced Microwave FMR Absorption and Bandwidth in a YIG/GGG-GaAs Flip-Chip Layer Structure*
Abstract::	Enhanced microwave ferromagnetic resonance (FMR) absorptions and bandwidth in yttrium iron garnet/ gadolinium gallium garnet-gallium arsenide (YIG/GGG-GaAs) flip-chip layer structures using a microstrip step-impedance low-pass filter (LPF) are reported. The measured transmission loss and return loss of –25.0 dB and –8.7 dB using the microstrip step-impedance LPF, at FMR frequency of 8.5 GHz, show a higher level of microwave FMR absorption in the YIG/GGG-GaAs layer structure as compared to a 50   microstrip. The microwave transmission characteristics of the magnetic over-layer in a large base band of 2.0-20.0 GHz were also measured. ____________ *Supported by UC Discovery Program;  Wang NMR Inc.

13
Author(s)::	Chengxiang Xiang, Michael A. Thompson, Aleix G. Güell, Erik J. Menke,  Prof. Reginald M. Penner* (email: xciang@uci.edu)
Affiliation(s)::	Department of Chemistry
Title::	Lithographically Patterned Nanowire Electrodeposition
Abstract::	Nanowire fabrication methods can be classified either as "top down", involving photo- or electron beam lithography, or "bottom-up", involving the synthesis of nanowires from molecular precursors. Lithographically Patterned Nanowire Electrodeposition (LPNE) combines attributes of photolithography with the versatility of bottom-up electrochemical synthesis. Photolithography is employed to define the position of a sacrificial nickel nanoband electrode that is recessed into a horizontal trench defined by the substrate surface and photoresist. This trench acts as a "nanoform" to define the height of an incipient nanowire during its electrodeposition.  The width of the nanowire is determined by the electrodeposition duration.  Removal of the photoresist and nickel reveals a nanowire - composed of gold, platinum or palladium - with a rectangular cross section and a height and width that can be independently controlled, and as small as 10 nm. The polycrystalline nanowires synthesized by LPNE can be electrically continuous for 1 c m.  Application of LPNE synthesized nanowires including thermocouples, crossed wires, and bimetallic wire arrays are briefly explored.

14	Prize Winner!
Author(s)::	Megan Bourg, Prof. Reginald M. Penner (email: mbourg@uci.edu)
Affiliation(s)::	Department of Chemistry
Title::	Towards Nanowire-Based Thermocouples
Abstract::	The ability to accurately measure temperature on the same time scale as a thermal process under investigation is important in many industrial processes.  A thermocouple, which consists of a junction between two dissimilar metals, is most often the device used for such measurements.  As the thermal mass of the junction decreases, the response time decreases and the spatial resolution increases.  Therefore, junctions containing nanowires should lead to faster response times and increased spatial resolution.  In order to initally investigate this, we prepared nanowire-thin film (NWTF) junctions consisting of electrodeposited nanowires and an evaporated film.  These devices measure temperature accurately and reproducibly, and have a response time of 1.9ms.  For comparison, the response time of a 125μm type J thermocouple was 5.7ms.  To improve upon the enhancements shown by NWTF devices, nanowire-nanowire (NWNW) junctions were also fabricated.  NWNW thermocouples measure temperature accurately and reproducibly, and have a response time of 0.7ms.  Neither type of nanowire- based thermocouple show a decrease in sensitivity.   The characterization of these thermocouple arrays by SEM, EDS, and thermal measurements will be presented.

15
Author(s)::	Attila Cangi, Peter Elliott, Donghyung Lee, Prof. Kieron Burke (email: attila.cangi@uci.edu)
Affiliation(s)::	Department of Physics and Astronomy / Department of Chemistry
Title::	Semiclassical Origins of Density Functionals
Abstract::	Since its foundation almost 80 years ago Density Functional Theory (DFT) has gained the status of a successful,widely-used theory in different areas of chemistry and physics.  To improve the predictions of DFT and apply it to ever larger system we have to approximate the components of the energy of a given system accurately and computationally inexpensively.  We show how functionals can be improved by analyzing the semiclassical limit of large particle number [1,2].

16	Prize Winner!
Author(s)::	E. Kalman, K. Healy, Prof. Z. Siwy (email: ekalman@uci.edu)
Affiliation(s)::	Department of Physics and Astronomy
Title::	Tuning of Ion Current Rectification by Signal Mixing
Abstract::	A new way of controlling the rectification of conical nanopores is by applying two periodic rectangular voltage signals of zero mean. We identified frequency ratios and phase differences at which one can enhance rectifying properties of the nanopores.

17
Author(s)::	Michael Kamboures (email: mkambour@uci.edu)
Affiliation(s)::	Department of Chemistry
Title::	A Computational Investigation of the Chemistry of NO2 on HNO3/NO3- Surfaces
Abstract::	Nitrous acid is a precursor to hydroxyl radical in urban air. The processes which produce this nitrous acid are unknown. Studies have indicated that photoinduced surface reactions are involved. We investigate this topic using ab initio methods.

18
Author(s)::	Matthew Powell (email: mrpowell@uci.edu)
Affiliation(s)::	Department of Physics and Astronomy
Title::	Ion current oscillations caused by sub-femtoliter volume precipitation in a nanopore
Abstract::	We show ion current oscillations under constant applied voltage through a nanopore. Negative charges on the pore walls allow ion concentrations to rise above Ksp causing precipitates to form and be removed which periodically blocks ion flow.

19
Author(s)::	Yuhong Wang, Kapilanjan Krishan, Prof. Michael Dennin (email: yuhongw@uci.edu)
Affiliation(s)::	Department of Physics and Astronomy
Title::	Statistical Properties of Flowing Foam