Academic Calendar

semester, 2015


Thursday, January 1st 2015

Friday, January 2nd 2015

Monday, January 19th 2015

Tuesday, January 27th 2015
2:30 pm:
Thesis Defense in 110 PAN
Speaker: Kent Bodurtha, University of Minnesota
Subject: Electronic transport in nanocrystalline germanium/hydrogenated amorphous silicon composite thin films
This is the public portion of Mr. Bodurtha's Thesis Defense.

Recent interest in composite materials based on hydrogenated amorphous silicon (a-Si:H) stems in part from its potential for technical applications in thin film transistors and solar cells. Previous reports have shown promising results for films of a-Si:H with embedded silicon nanocrystals, with the goal of combining the low cost, large area benefits of hydrogenated amorphous silicon with the superior electronic characteristics of crystalline material. These materials are fabricated in a dual-chamber plasma-enhanced chemical vapor deposition system in which the nanocrystals are produced separately from the amorphous film, providing the flexibility to independently tune the growth parameters of each phase; however, electronic transport through these and other similar materials is not well understood. This thesis reports the synthesis and characterization of thin films composed of germanium nanocrystals embedded in a-Si:H. The results presented here describe detailed measurements of the conductivity, photoconductivity and thermopower which reveal a transition from conduction through the a-Si:H for samples with few germanium nanocrystals, to conduction through the nanocrystal phase as the germanium crystal fraction XGe is increased. These films display reduced photosensitivity as XGe is increased, but an unexpected increase in the dark conductivity is found in samples with XGe > 5% after long light exposures.


Friday, March 6th 2015
11:00 am:
Special Space Physics Seminar in 435 Tate Lab of Physics
Speaker: Lois Sarno-Smith, University of Michigan
Subject: High Energy" Ion depletion in the Post-Midnight Plasmasphere - Using the Van Allen Probes Satellite Suite to Uncover Mysteries of the Inner Magnetosphere

Using the Helium Oxygen Proton Electron (HOPE) instrument, Electric Fields and Waves (EFW), and the Electric and Magnetic Field Instrument Suite (EMFISIS) instruments, we examine how combining multiple instruments that characterize plasma can enable us to under how the 1-10 eV ion population, where the bulk of the plasmasphere lies, experiences strong local time asymmetry.


Monday, March 16th 2015

Tuesday, March 17th 2015

Wednesday, March 18th 2015

Thursday, March 19th 2015

Friday, March 20th 2015

Wednesday, April 22nd 2015
10:30 am:
Thesis Defense in 110 PAN
Speaker: Xiangwei Tang, University of Minnesota
Subject: Observations of Plasma Waves at the Earth's Dayside Magnetopaus
This is the public portion of Ms. Tang's thesis defense.

Thursday, April 23rd 2015
10:00 am:
Thesis Defense in PaN 110
Speaker: Addis Woldesenbet, University of Minnesota
Subject: Model-free analysis of quadruply imaged gravitationally lensed systems.
This is the public portion of Ms. Woldesenbet's thesis defense.
7:00 pm:
Speaker: Margaret J. Geller, Harvard-Smithsonian Center for Astrophysics
Subject: Click: The 3D Universe
This is event is free and open to the public. It is scheduled to last an hour.

We live in the first time when it is possible to map the universe. We now know that galaxies like our own Milky Way trace the largest patterns in nature. These patterns, first uncovered by the CfA redshift survey in 1986-1989, extend for hundreds of millions of light years. Now with large telescopes, we can trace the evolution of these patterns and compare them with some of the worlds largest computer simulations. A new survey, HectoMAP shows us the patterns in the universe nearly 7 billion years ago. A HectoMAP movie takes us through the data. Comparison of HectoMAP observations with simulations provides new direct tests of our understanding of the evolution of structure in the universe.


Saturday, May 2nd 2015
08:30 am:
Soudan Laboratory Open House in Soudan Underground Laboratory
Last tour starts at 3:30 p.m.

The Soudan Underground Physics Lab is holding an open house on Saturday, May 2, starting at 8:30 a.m. and continuing throughout the day. Visitors can travel 1/2-mile underground and discover the data collected during the years that the MINOS detector has been operating. The Fermi National Accelerator Lab has been sending a beam of neutrinos to the Soudan Lab since the first one was detected on March 20, 2005.


Thursday, May 7th 2015
1:25 pm:
Speaker: Mitchell Wendt, University of Minnesota
Subject: The Detection of Bright but Rare Particles Carrying One or Two Distinct Fluorescent Colors: A Simulation Study

Friday, May 8th 2015
11:15 am:
Methods of Experimental Physics Poster Session in Physics and Nanotechnology Building Atrium
1:00 pm:
Speaker: Benjamin Ihde, University of Minnesota
Subject: Statistical Validation of Density-Specific-Volume Covariance Transport in a Two-Fluid System

Monday, May 11th 2015
1:25 pm:
Speaker: Exra Hart, University of Minnesota
Subject: Investigation of Missing Cell Events to Improve NOvA Far Detector Data
4:40 pm:
Speaker: Asad Kahn, University of Minnesota
Subject: Study of source of timing variations in ECAL using Z to ee events

Friday, June 5th 2015
10:00 am:
Thesis Defense in 110 PAN
Speaker: Chaoyun Bao, University of Minnesota
Subject: Foreground Cleaning for Cosmic Microwave Background Polarimeters in the Presence of Instrumental Effects

Thursday, June 11th 2015
2:00 pm:
Thesis Defense in 110 PAN
Speaker: J J Nelson, University of Minnesota
Subject: Hopping Conduction and Metallic behavior in 2D Silicon Surface States induced by an Ionic Liquid
This is the public portion of Mr. Nelson's thesis defense.

Saturday, June 13th 2015
11:00 am:
Memorial Service in First Unitarian Society, Minneapolis
There will be a memorial service for the late Professor Erwin Marquit at the First Unitarian Society in Minneapolis located at 900 Mount Curve Avenue.

Wednesday, June 24th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.

Wednesday, July 8th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.

Wednesday, July 15th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.

Wednesday, July 22nd 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.

Wednesday, July 29th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.

Monday, August 3rd 2015
1:30 pm:
Thesis Defense in 110 PAN
Speaker: Bern Youngblood, University fo Minnesota
Subject: Noise and stochastic resonance in nanoscale magnetic particles
This is the public portion of Mr. Youngblood's thesis defense.

Wednesday, August 5th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.

Tuesday, August 11th 2015
10:00 am:
Thesis Defense in 110 PAN
Speaker: Susan Lein, University of Minnesota
Subject:  Muon Neutrino Contained Disappearance in NOvA
This is the public portion of Ms. Lein's Thesis Defense.

The NOvA experiment studies neutrino oscillations in the NuMI neutrino beam from Fermilab. NOvA consists of two liquid scintillator tracking calorimeters placed
14 milliradians off-axis from the beam and 810 km apart. The NOvA experiment started taking data in 2014. This thesis establishes the neutrino energy estimation procedures used to determine the oscillation parameters sin^2 theta_23 and Delta m_{32}^2.


Wednesday, August 12th 2015
Speaker: REU Stduents, with Welcome by Alex Kamenev, University of Minnesota
Subject: See abstract for titles

8:55 a.m., Alex Kamenev, Welcome
9:00 a.m., Katelyn Koiner (Lucy Fortson) "Galaxy Zoo and UKIDSS: comparing bars in disc galaxies in optical and infrared wavelengths"
9:20 a.m., Austin Riedl (Michael Zudov) "Effect of low-temperature illumination and annealing on magnetotransport in very high Landau levels"
9:40 a.m., Aditya Dhumuntarao (Joe Kapusta) "AdS/CFT on Pure SU(3) Gauge Theory"
10:00 a.m., Shannon Dulz (Prisca Cushman) "Monte Carlo Simulations and Polymerization of Neutron Veto Plastics for the SuperCDMS Experiment"
10:20 a.m., Coffee Break
10:40 a.m., Matthew Libersky (Allen Goldman) "Ionic liquid gating of strontium iridate"
11:00 a.m., Bryan Linehan (Marvin Marshak) "Measuring the Sun and Moon Cosmic Ray Shadow on the NOvA Far Detector"
11:20 a.m., Sadie Tetrick (Cindy Cattell) "Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss: a further study"
11:40 a.m., Jon Huber (Woods Halley) "Magnetite Anodes used in the electrolysis of water"
12:00 p.m., Lunch
12:45 p.m., Wilson Lough (Vuk Mandic) "Signal Processing and Detection of the Gravitational Wave Background"
1:05 p.m., Miranda Thompson (Jim Kakalios) "Electronic Conductance in Silicon Nanocrystalline Films"
1:25 p.m., Joseph Mullin (Greg Pawloski) "Exploring Neutrino Oscillations at the Minos Near Detector"
1:45 p.m., Coffee break
2:00 p.m., Phillip Dang (Paul Crowell) "Magnetotransport Properties of Co2MnSi and Co2FeSi Heusler Alloy Thin Films"
2:20 p.m. Kylie Hess (Roger Rusack) "Fabrication of a Cosmic Ray Detector and Creation of Accompanying Data-Processing Code"
2:40 p.m., Timothy Schuler (John Broadhurst) "Auditory Discrimination in the Human Brain"
3:00 p.m., Program ends


Friday, August 21st 2015
10:30 am:
Thesis Defense in 110 PAN
Speaker: Andrew Galkiewicz, University of Minnesota
Subject: Magnetic domain wall dynamics in patterned nanowires
2:00 pm:
Thesis Defense in 110 PAN
Speaker: Kanika Sachdev, University of Minnesota
Subject: Muon to Electron Neutrino Oscillation in NOvA

NOvA is a long-baseline neutrino oscillation experiment optimized for electron neutrino appearance in the NuMI beam, a muon neutrino source at Fermilab. It consists of two functionally identical, nearly fully-active liquid-scintillator tracking calorimeters. The near detector (ND) at Fermilab is used to study the neutrino beam spectrum and composition before oscillation, and measure background rate to the electron neutrino appearance search. The far detector, 810 km away in Northern Minnesota, observes the oscillated beam and is used to extract oscillation parameters from the data. NOvA's long baseline, combined with the ability of the NuMI beam to operate in the anti-neutrino mode, makes NOvA sensitive to the last unmeasured parameters in neutrino oscillations- mass hierarchy, CP violation and the octant of mixing angle theta23. This thesis presents the search for electron neutrino appearance in the first data collected by the NOvA detectors from February 2014 till May 2015. Studies of the NuMI neutrino data collected in the NOvA near detector and its effect on the oscillation measurement in the far detector are also presented.


Thursday, August 27th 2015
09:00 am:
Physics Force Public Show in Carousel Park, MN State Fair

Monday, August 31st 2015
10:00 am:
Physics Force Public Show in University of Minnesota Stage, MN State Fair
11:00 am:
Physics Force Public Show in University of Minnesota Stage, MN State Fair

Friday, September 4th 2015
10:00 am:
Thesis Defense in 120 PAN
Speaker: Zhen Yuan, University of Minnesota
Subject: A Model for Gas Dynamics and Chemical Evolution of the Fornax Dwarf Spheroidal Galaxy
This is the public portion of Zhen Yuan's thesis defense.

We present an empirical model for the halo evolution, global gas dynamics and chemical evolution of Fornax, the brightest Milky Way (MW) dwarf spheroidal galaxy (dSph). Assuming a global star formation rate, we derive the evolution of the total mass and the rate of net gas flow for cold gas in a growing star-forming disk. We identify the onset of the transition from net inflow to a net outflow as the time at which the Fornax halo became an MW satellite and estimate the evolution of its total mass using the median halo growth history in the ΛCDM cosmology and its present mass within the half-light radius derived from observations. We find that the Fornax halo grew to M h (t_sat ) ≈ 1.8 × 10 9 M ⊙ at t sat ≈ 4.8 Gyr and that its subsequent global gas dynamics was dominated by ram-pressure stripping and tidal interaction with the MW. Then we build a chemical evolution model on a 2-D mass grid, using supernovae as the enrichment source of the gaseous system. We find that the key parameter of controlling the element abundances pattern is the supernovae mixing mass. It is set differently between two types of supernovae and between two phases, before and after t sat in our model. The choice is determined based on the supernovae remnant evolution as well as the global gas dynamics. We also find the metal loss in the outflow dominated phase is severe, which is empirically implemented in our model. The data generated from the standard case can explain the observational data very well, e.g., abundance ratio of α element to Fe as a function of metallicity [α/Fe] vs. [Fe/H], metallicity evolution as a function of time [E/H] vs. t and metallicity distribution function (MDF) for Mg, Ca and Fe.


Monday, September 7th 2015

Friday, September 11th 2015
1:30 pm:
Thesis Defense in PAN 120
Speaker: Joe Kinney, University of Minnesota
Subject: Kinetic Inductance and Ionic Liquids, Tools for Understanding High-Tc Superconductors
This is the public portion of Mr. Kinney's thesis defense.

Sunday, September 27th 2015
12:00 pm:
School picnic in Boom Island Park
Please go here for map and RSVP information.

To help cover costs of this event, we are asking attendees to contribute 10forfaculty,and- 5 for postdocs, staff, and students (no charge for family members). If you would rather bring food, you may bring a side dish or dessert to share instead of paying. You can bring your payment to the picnic if you haven't already paid.


Thursday, October 8th 2015
3:15 pm:
School Photo in Steps of Civil Engineering Building
Refreshments will be served in the PAN lobby at 3:00 p.m.

Wednesday, October 21st 2015
08:00 am:
Thesis Defense in 110 PAN
Speaker: Kwang Ho Hur, University of Minnesota
Subject: Advancing Fluorescence Fluctuation Microscopy in living cells: From non-stationary signals to tricolor FFS
This is the public portion of Mr. Hur's Thesis Defense.

Fluorescence fluctuation spectroscopy (FFS) is a powerful method for quantifying protein interactions. By exploiting the brightness of fluorescence intensity fluctuations we are able to measure the stoichiometry of protein complexes. FFS is particularly valuable because it allows real-time measurements within living cells, where protein complex formation plays a crucial role in the regulation of cellular processes. However, intensity fluctuations are frequently altered by the cell environment in subtle and unanticipated ways, which can lead to failure of the available FFS analysis methods. This thesis demonstrates that measuring in very small volumes, such as yeast and E. coli cells, can introduce a significant bias into the measured brightness as a result of cumulative sample loss, or photodepletion. This loss leads to a non-stationary signal, which is incompatible with the implicit assumption of a stationary process in conventional FFS theory. We addressed this issue by introducing a new analysis approach that serves as a foundation for extending FFS to non-stationary signals.
FFS measurements in cells are also currently limited to the study of binary interactions involving two different proteins. However, most cellular processes are mediated by protein complexes consisting of more than two different proteins. Observation of pairwise interactions is not sufficient to unequivocally determine the binding interactions involving three or more proteins. To address this issue, we extended FFS beyond binary interactions by developing tricolor heterospecies partition analysis to characterize ternary protein systems. The method is based on brightness analysis of fluorescence fluctuations from three fluorescent proteins that serve as protein labels. We verified tricolor heterospecies partition analysis by experiments on well-characterized protein systems and introduced a graphical representation to visualize interactions in ternary protein systems.


Tuesday, November 3rd 2015
10:00 am:
Thesis Defense in PaN 120
Speaker: Tambe Ebai Norbert, University Of Minnesota
Subject: Search for massive long-lived neutral particles decaying to photons and large missing transverse energy using the Compact Muon Solenoid(CMS) particle detector.
This the public portion of Mr. Norbert's defense. His advisor is Yuichi Kubota.

The Standard Model (SM) despite its unmatched success in describing visible matter in the universe does not describe massive long-lived neutral particles. Therefore any sign of a massive long-lived neutral particle at the Large Hadron Collider(LHC) for example, would be an indication for new physics. Many models Beyond the SM like Gauge Mediated Supersymmetry Breaking Models(GMSB), Split SUSY models, Hidden Valley models and Large Extra Dimension models predict the existence of a massive long-lived neutral particle which decays into a photon and a gravitino.
Capitalizing on the excellent timing resolution of the Electromagnetic Calorimeter(ECAL) of the CMS detector, this thesis presents the search for events whose final state consist of at least one photon with late arrival time at ECAL compared to photons produced directly from proton-proton collisions at the LHC and large missing transverse energy in data recorded by the CMS detector from proton-proton collisions at 8 TeV center of mass energy in 2012. This data corresponds to 19.1/fb total integrated luminosity.
A photon from the decay of a massive long-lived neutral particle arrives late at ECAL due to the long lifetime of the massive long-lived neutral particle and is detectable using timing measurements of photons by ECAL. The large missing energy is used to infer the presence of an undetectable particle like the gravitino produced along with the photon from the decay of the massive long-lived neutral particle. The search covers particle lifetimes ranging from 3 to 40 nanoseconds(10^-9s).


Thursday, November 5th 2015
Pizza lunch, lab tours, an overview of the School, and a chance to win a copy of the book The Physics of Superheroes.

More information here.

Subject: Overview of the school, lab tours, admissions information and a performance by the Physics Force.

More information here.


Friday, November 6th 2015
3:30 pm:
Warren Lecture Series in Civil Engineering 210
Speaker: Victor Berdichevsky, Wayne State University, Detroit
Subject: Variational Principle for Probabilistic Measure in Theory of Materials with Random Microstructures and Beyond

Materials with random microstructures can be adequately described only in probabilistic terms. One of the problems that arise is: how to find probabilistic characteristics of local fields (stresses, currents, etc.), if probability distributions of material characteristics are known? This is one of the two topics of the talk. The second topic is closely related to the first one and concerned thermodynamics of microstructure evolution. It will be argued that classical thermodynamics is not sufficient for macroscopic description of solids, and there is one more law of thermodynamics which controls evolution of microstructures.


Monday, November 23rd 2015
4:00 pm:
Thesis Defense in 434 PAN
Speaker: Michael Albright, University of Minnesota
Subject: Thermodynamics of Hot Hadronic Gases at Finite Baryon Densities
This is the public portion of Mr. Albright's thesis defense. His advisor is Joseph Kapusta

The universe is filled with protons and neutrons, which are themselves made of quarks and gluons. However, microseconds after the Big Bang, the universe was so hot and dense that quarks and gluons existed in other phases--first as a quark-gluon plasma, then as a hadron gas. Remarkably, these exotic phases of matter are created and studied experimentally in heavy-ion collisions at particle accelerators like RHIC at Brookhaven National Lab and the LHC at CERN. There is a strong effort underway to develop precision models of heavy-ion collisions which, combined with experimental data, will enable improved determination of many physical properties of quark-gluon matter. Recent years have seen significant improvements in modeling matter with zero net baryon density, which is relevant for RHIC, the LHC, and the early universe. However, there is growing interest in matter with a large net baryon density, which is relevant for neutron stars and future collider experiments. Hence, in this thesis we compute various thermodynamic properties of matter at large baryon densities. We first improve the popular hadron resonance gas equation of state (EoS) by including repulsive interactions, which are important at large baryon densities. Next, we develop crossover equations of state which smoothly transition from hadron gas models at low energy densities to a quark-gluon plasma EoS at high energy densities. We then compute net baryon number fluctuations and compare them to measurements from the STAR Collaboration at RHIC. We find that fluctuations freeze out long after chemical reactions do. Finally we develop a relativistic quasiparticle kinetic theory of hadron gases at large baryon densities. This includes interactions via scalar and vector mean fields in a thermodynamically consistent way. We then derive formulas for the shear and bulk viscosity and thermal conductivity, which are interesting quantities that influence experimental observables.


Thursday, November 26th 2015

Friday, November 27th 2015

Thursday, December 10th 2015
09:30 am:
Thesis Defense in PAN 120
Speaker: Xin Li, University of Minnesota
Subject: Phenomenology of Hadrons Containing Heavy Quarks
This is the public portion of Mr. Li's thesis defense. His adviser is Mikhail Voloshin.

Recent experiments have brought us new surprises about old quarkonium system. A series of exotic resonances are discovered in electron-positron colliders and new hadronic processes are measured. I will discuss some aspects of those new experimental results. The heavy quark spin symmetry and QCD-based method will be used to understand those results.


Friday, December 11th 2015
7:00 pm:
Bell Museum Social in Bell Museum of Natural History
Speaker: Larry Rudnick, University of Minnesota
Subject: The Biggest Things in the Universe

Wednesday, December 16th 2015

Thursday, December 17th 2015

Wednesday, December 23rd 2015

Thursday, December 24th 2015

Friday, December 25th 2015

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.