Date |
Host |
Speaker |
Title of the talk |
Abstract |
Aug. 28
|
Dubois
|
Oscar de Lucio (UNAM, Mexico City)
|
Applications of the 5.5 MV Van de Graaff Accelerator at IF-UNAM
for IBA techniques
|
Over the last three
decades the 5.5 MV Van de Graaff accelerator at IF-UNAM has been
commissioned for materials analysis, establishing several
collaborations with a variety of research groups. Recently, a major
upgrade has been performed allowing the use of more beamlines and the
inclusion of a variety of new research projects. Some examples of the
applications and current research performed at the Van de Graaff
accelerator will be presented, with particular emphasis on the use of
Ion Beam Analysis (IBA) techniques for materials characterization.
Results from such techniques allow the quantification of elemental
profiles in diverse samples, and has proven to be a unique and powerful
tool specially for the measurement of light elements such H, Li, C, N,
O.
|
Sept. 4
|
|
|
|
|
Sept. 11 |
Medvedeva
|
Alexander Goldberg (Schrödinger Inc.)
|
Schrödinger High-throughput Atomic Scale Simulations to Discover New Materials for Industrial Applications
|
With
the rapid increase in computer power, molecular modeling with its
virtual screening paradigm has a great potential for discovering and
optimizing material solutions for diverse industries. For example,
recently Professor Thompson of the University of Southern California
used Schrödinger simulation tools to evaluate 205,000 organic compounds
for use in photovoltaic devices. This work would have taken 264 years
on conventional computers but was finished in 18 hours by running on
156,000 cores simultaneously, opening a new era in scientific
computing. To date the number of studies applying first-principles
calculations in a high-throughput fashion is limited; however with the
fast advances in multicore computers and the availability of temporary
cloud resources, virtual screening will become indispensable instrument
in a search for new materials in many industrial applications. In this
presentation, an overview of the Schrödinger Materials Science Suite is
given and the use of high-throughput quantum chemistry to analyze and
screen a chemical structure library is demonstrated for key materials
applications including organic light-emitting diode (OLED), precursors
for Atomic Layer Deposition (ALD) and materials for hydrogen storage
and transportation.
|
Sept. 18
|
Waddill
|
Department meeting
|
|
|
Sept. 25 |
|
|
|
|
Oct. 2
|
Medvedeva
|
Risheng Wang (Chemistry, Missouri S&T)
|
DNA Engineering: From Structure to Application
|
Deoxyribonucleic
acid (DNA), as you may very well know, is the carrier of generic
information in living cells, which can replicate itself through
Watson-Crick base paring. However, over the past three decades,
researchers in the emerging field of DNA nanotechnology have been using
the DNA as structural nanomaterials, based on its unique molecular
recognition properties and structural features, to build addressable
artificial nanostructures in one, two and three dimensions [1,2]. These
self-assembled nanostructures have been used to precisely organize
functional components into deliberately designed patterns which have a
wide application potential in material science, biomedical, electronic
and environmental fields [3].
The development of DNA nanotechnology and its potential application
will be introduced first. Then my talk will focus on the design and
construction of several DNA nanostructures, including 1) self-assembly
of DNA six-helix nanotubes from two half-tube components. The main
advantage of this assembly strategy is that it can provide a hollow
system to conveniently sheath other components, which makes such
nanotubes ideal candidates to serve as scaffolds to organize and
control tubular materials for biomedical and electronic applications.
2) Using DNA origami template to organize semiconducting quantum dots
(QDs) and gold nanoparticles (AuNPs). The controllable assembly of
heterogeneous nanomoeities opens new opportunities for the creation of
complex nanoassemblies, which can display unique properties based on
programmable interactions between electro-optically active
constituents. 3) Discussing the techniques of combining lithographic
patterning with bio-molecular assembly to produce highly ordered,
self-assembled arrangements of nano-objects. This integration of
“top-down” nanofabrication technique and “bottom-up” self-assembly is
opening new opportunities for the creation of devices and circuits in
nanoscale.
References:
1. N. C. Seeman, Mol Biotechnol, 2007, 246-257.
2. A. V. Pinheiro, D. Han, W. M. Shih and H. Yan, Nature Nanotechnology, 2011, 763-772.
3. F. A. Aldaye, A. L. Palmer and H. F. Sleiman, Science, 2008, 1795-1799.
|
Oct. 9
|
Kurter
|
Pouyan Ghaemi (CUNY)
|
Electronic world on the edge
|
The band structure of a solid, one of the most important results of quantum theory, explains
the relationship between the energy of electrons and the quantum wave-vector that labels
their state. The band structure is the basic foundation for understanding the properties
of semiconductors, which, for instance, has been responsible for much of the development
in the electronics industry. We now know that the electronic band
structure contains more information than solely the relationship of
energy and wave-vector of electrons. This information which is stored
in quantum wave function of electrons in solids distinguishes
many new electronic phases with novel properties. In many cases the
signature of these new phases appears as the robust electronic edge
states. These edge states are realized in easily accessible conditions
and present a macroscopic signature of quantum theory. In this talk I
discuss some examples of solids with such robust electronic edge state,
the novel electronic phases that can be stabilized on the edge of these
materials and how they can open the door for new applications.
|
Oct. 17 |
Madison
|
Homecoming: Matthew Foster
|
Aircraft Carriers, Bytes, and Physics: The Fate of a Missouri S&T Physicist
|
Matthew
Foster discusses the transition from a budding atomic physicist into a
rebellious operations research scientist. He shares his journey from
the high desert of Los Alamos, NM, through the picturesque views of
Bagram, Afghanistan, and ending at shores of Hampton Roads, VA. In
2008, Matthew semiofficially retired as a physicist and joined the
Center for Naval Analysis (CNA), the U.S. Navy’s Federally Funded
Research and Development Center (a.k.a. think tank). During World War
II, German U-boats plugged and ravaged American shipping lanes, halting
supplies to Europe. The U.S. Navy enlisted MIT professor Philip
Morse, the first CNA field representative — Matthew’s current position
— and founder of modern operations research (OR). Morse led the
scientific team that developed effective escort screening plans and
designed antisubmarine warfare tactics. Matthew accounts classic
operation research problems and modern examples from his personal
experiences in Operation Enduring Freedom. Finally, he brags about his
degrees of separation between himself and the White House via the
classic, now cheesy, 1980’s movie Top Gun.
|
Oct. 23 |
Hor
|
David Hseih (Caltech)
|
Quantum states of matter in crystals
|
We have
all encountered the three classical states of matter: solid, liquid and
gas. But what is a quantum state of matter, where do we find them and
what are they good for? In this talk we will explore the behavior of
electrons in crystals and examine how the interactions between
electrons and their crystalline host can generate a large variety of
unusual states of matter that exhibit macroscopic quantum properties.
Exactly which crystals to search in, their potential technological
applications and practical feasibility will all be addressed.
|
Oct. 30
|
Hagen
|
Otmar Schmid
|
Aerosol Science in Health Research
– or –
What the Heck Can You Do with Cloud and Aerosol Science?
|
With
every breath inhaled aerosol is depositing in the lung. The fate and
biological effects of these particles depend on physiological
parameters mechanisms and the properties of these particles such as
size, shape and material. Obviously, inhalation of aerosols can be
friend and foe: While therapeutic aerosol offers attractive options for
non-invasive pulmonary and systemic drug delivery, the exposure to
potentially toxic aerosol such as soot or engineered nanomaterial
raises health concerns.
These issues are studied in model systems of biology such as cell
systems, tissue slices and organs as well as animal models. One of the
most ambitious projects in this field is the design of an in-vitro
organism consisting of a network of bioreactors representing the
various organs using organ-specific cells. Ideally, these in-vitro
organisms could make substance testing on animals obsolete. Cloud and
aerosol science is an essential part of this highly interdisciplinary
research field as evidenced by awarding the Nobel Prize 2002 in
Chemistry to John Bennett Fenn for discovering that electrospray
aerosolization allows for soft ionization and subsequent mass
spectrometric analysis of biological samples without fragmentation of
biological macromolecules.
In this presentation various examples of the essential role of aerosol
science in health research is given with an emphasis on my own work
during the past decade. The focus will be on innovative methods of
aerosolized drug delivery to cell systems, animal models and patients
as well as the assessment of toxicological effects of inhaled
nanoparticles and recent advances in in-vivo imaging of the bioactive
pulmonary drug dose in small animals.
|
Nov. 6
|
Kurter
|
Nicholas Butch (NIST Center for Neutron Research)
|
Adventures in electron correlations
|
Sitting
at the bottom of the periodic table, the lanthanide and actinide
elements may seem like a dreary bunch, but they are responsible for
some of the most interesting phenomena in condensed matter physics. At
the heart of it all is the complicated manner in which the f-electrons
interact with other electrons. I’ll discuss two of the more
unusual cases of current interest: Kondo topological insulators and
hidden order.
|
Nov. 13
|
Kurter
|
Aaron Finck (UIUC)
|
Searching for Majorana Fermions in Hybrid Topological Insulator Devices through Interferometry
|
Topological
superconductors have been predicted to host exotic bound states
commonly referred to as Majorana fermions, which possess non-Abelian
exchange statistics. One can engineer a topological
superconductor by coupling a conventional s-wave superconductor with
the helical surface states present in a topological insulator. In
this talk, I will describe our efforts to probe unconventional
superconductivity using phase coherent transport in topological
insulator interferometers with superconducting leads. We observe
prominent Fabry-Perot oscillations that become strongly modified at low
energies due to Andreev reflection. At high magnetic fields, we
detect periodic $\pi$ phase shifts in the Fabry-Perot oscillations that
can be linked to the intrinsic Berry phase of the helical surface
states. We relate these observations to the on-going search for
Majorana fermions in solid state systems.
|
|
Nov. 20
|
Medvedeva
|
Reuben Collins (Colorado School of Mines)
|
Hot carrier transfer in nanocrystalline silicon
|
The
optical and electronic properties of semiconductor quantum dots have
generated considerable scientific and technological interest.
Nanocrystalline silicon, which consists of silicon quantum dots
embedded in an amorphous silicon matrix, is, in some sense, one of the
earliest of these nanomaterials. It has applications extending
from photovoltaics to thin film transistors. We have recently
discovered unexpected carrier dynamics in this system. Charges
photoexcited in the amorphous region transfer to quantum dots before
relaxing into localized states; a form of hot carrier transfer.
This observation provides insight into interesting properties of
nanocrystalline silicon. This talk will introduce nanocrystalline
silicon, discuss its properties, and present new approaches for
synthesizing material with controllable quantum dot size in the sub
10nm regime.
|
Dec. 4
|
Medvedeva
|
Eighteenth Annual Laird D. Schearer Prize
Competition
|
|
|