Prof. Ed Cussler

The award also noted his work with the AIChE Journal as well as the Journal of Membrane Science, his authorship of 250 publications, 8 patents, and 5 texts as evidence of his being "...equally, and perhaps above all, a professor and communicator without peer."

Prof. Yiannis Kaznessis

The current rapid expansion of biological knowledge offers a great opportunity to rationally engineer biological systems that respond to external signals. Indeed, the ambitious idea of engineering biological cells that function as miniature factories has given rise to a new, exciting field of research, synthetic biology.

The inherent complexity of living organisms warrants a quantitative perspective for rationalizing the construction of synthetic biosystems. Professor Kaznessis and his group focus on the development of statistical mechanical theories and accurate mathematical models of biomolecular events that provide insight into the dynamic behavior of biological systems. They also work on designing and experimenting with synthetic biological systems, such as protein devices, inducible gene networks and bio-logical AND gates, with applications in biofuels, biosensors and gene therapies.

Kevin Dorfman

These "artificial gels" promise to be much better than conventional gel electrophoresis of long DNA, reducing the separation time from hours to minutes and increasing the reproducibility. The problem is that, although there is now pretty good data for the interactions of long DNA and a single isolated obstacle, they do not have a good model for the dynamics of DNA as it moves through an array of many obstacles. They are going to observe these dynamics at the single-molecule level and then use coarse-graining techniques to develop models for the separation process. If successful, the project would yield design equations for the separation.

Efie Kokkoli

Her group focuses on synthesizing and characterizing bioactive peptide-amphiphiles for the design of receptor targeted therapeutics. They attempt to compare and link measurements that address widely different length scales and dynamics, ranging from the single-molecule level all the way to the cell. Different peptide-amphiphiles designed in Efie's lab are further evaluated in their ability to provide targeting functionality to drug delivery systems. Biomimetic peptide-amphiphiles also hold promise for the creation of functional nanostructures and a future goal is to use them for templated materials synthesis.

Martin Kenward, a postdoc with Kevin Dorfman, won a supercomputing research scholarship from the MSI for the coming fiscal year (July-June). The title of the project is: "Biophysical mechanisms underlying DNAzyme catalysis." DNAzymes are short sequences of single-stranded DNA that act as catalysts when folded in the presence of a cofactor. The most promising DNAzyme, which catalyzes chain scission of mRNA at the start codon, has spawned an active area of clinical research. To date, all DNAzymes have been discovered in the laboratory by directed evolution. Current directed evolution techniques limit DNAzymes to approximately 20 bases, and changing a single base can reduce the catalytic rate by several orders of magnitude. Thus, relating a particular DNAzyme’s sequence to its structure (and fluctuations around that structure) is crucial to understanding their biochemistry, and will aid in the first-principles discovery of new, more powerful enzymes for biotechnology and clinical applications. The specific aim of this project is to correlate insights gained from statistical physics with available biochemical rate data in order to determine the structural features that give rise to stable, highly active DNAzymes.

Frank Bates gave the Berkeley Lectures in early March. He gave seminars on �Block Copolymer Phase Behavior: Can Theory Keep Pace?�. The Berkeley Lectures in Chemical Engineering have been a proud tradition sponsored by the Department of Chemical Engineering at the University of California, Berkeley since 1985. The Berkeley Lecturer is an outstanding academic or industrial researcher who presents two lectures over a three day period of time.

Jeff Derby

Jeff Derby will be giving two seminars this spring. The first is at Texas Tech University in Lubbock, TX in the Department of Chemical Engineering on March 9. The talk is on "Modeling the Interaction of Multiple Scales in Melt and Solution Crystal Growth."

Jeff will also be speaking at a Colloquium about Crystal Growth of Semiconductors and Optical Crystals. The colloquium is on the Occasion of the Official Retirement of Prof. Dr. H. C. Georg Müller, Fraunhofer Institute of Integrated Systems and Device Technology (IISB) in Erlangen, Germany. Jeff's talk on May 4, 2007 is entitled "Virtual crystal growth -- a dream or reality?"

Funding is also provided for Yeckel to travel within Germany to interact with scientists at other institutions, both academic and industrial. Planned visits include Schott, a manufacturer of advanced glass and photovoltaics; Deutsche Solar, a world leader in production of photovoltaic silicon; and the renowned Institute for Crystal Growth (IKZ) in Berlin. Dr. Yeckel will return to CEMS in April to continue his collaboration with Jeff Derby.

Renata Wentzcovitch

Electronic spin is a quantum property of every electron, associated with its intrinsic angular momentum. The electronic structure of iron in minerals is generally such that valence electrons will more abundantly occupy different spatial orbitals and maintain the same spin than occupy the same spatial orbital and assume opposite spin, called ‘spin-paired.’ To the astonishment of mineral physicists, pressure-induced electronic spin-pairing that were predicted in iron nearly 50 years ago recently have been detected in ultrahigh-pressure experiments.

You can link to the complete article below.

Third year CEMS graduate student Kurtis Leschkies was one of three students chosen to receive a scholarship awarded by the Particle Society of Minnesota. This scholarship is given to outstanding students whose research and interests focus on particle science and engineering. Kurtis is working on nanoparticle based quantum dot solar cells and is coadvised by Professors Norris and Aydil in CEMS and Professor Kortshagen from the Mechanical Engineering Department. The winners were selected based on their exemplary academic record and research in areas of particle science and engineering. The winners of the scholarship will receive $1000 and will be invited to present their research during a lunch meeting of the Particle Society membership in spring of 2007.

Chris Leighton had a recent paper in Physical Review Letters: "Exchange Bias as a Probe of the Incommensurate Spin-Density Wave in Epitaxial Fe/Cr(001) with J.S. Parker, L. Wang, K. A. Steiner, P.A. Crowell (Phys. Rev. Lett. 97 227206 (2006)).

Magnetism in metallic films and interfaces has been intensively studied since the discovery of Giant MagnetoResistance (GMR) in the late 1980’s. This effect enabled fabrication of high sensitivity magnetic field sensors for the read heads in magnetic hard disks, revolutionizing magnetic recording. GMR occurs in structures where an ultra-thin “non-magnetic” film is sandwiched between two magnets, Fe / Cr / Fe being a popular example. Although often ignored, the weak magnetism of the Cr film is fascinating in its own right. As in all magnets, this magnetism originates from the arrangement of the spin magnetic moments of the electrons. Cr has one of the most extraordinary spin arrangements that can be found in the entire periodic table. The spins form a structure that is referred to as an antiferromagnetic Incommensurate Spin Density Wave. As shown in the figure, this involves a periodic modulation of the Cr spin, with a wavelength that does not match (i.e. is incommensurate with) the atomic periodicity. Postdoc Jeff Parker, working with graduate student Lan Wang, undergraduate Kim Steiner, and Professors Leighton and Crowell have used a well-known effect in thin film magnetism to directly probe this spin structure even in very thin films where other techniques cannot be applied. The work is based on the concept of interfacial exchange coupling between neighboring layers, using an effect called exchange bias. Exchange bias is an easily measurable perturbation of the properties of a ferromagnetic film due to proximity to an antiferromagnet like Cr. Its great sensitivity to the interface spins in the antiferromagnet means that in Fe/Cr thin film layers one can use the exchange bias in the Fe to probe the spin arrangement in the Cr. In particular, the wavelength of the Cr spin density wave varies with temperature, leading to an oscillation in the Cr surface spin magnitude, and therefore an oscillation in the strength of the coupling to the Fe, with temperature. By measuring these oscillations they were able to determine, in a unique way, important and detailed information on the spin density wave, such as the extent of the wavelength change with temperature, and the critical temperatures at which the nature of the spin density wave changes. The experiment required not only the fabrication of high crystalline perfection epitaxial Fe/Cr films (with very smooth interfaces) but also measurement of the exchange coupling strength to very high accuracy due to the small magnitude of the oscillations.

Michael Tsapatsis gave the 2006 Van Ness Award Lectures at RPI (October 11 and 12) and Merck Sharp and Dohme 2006 Lectures at UPR Mayaguez.

David Norris has been elected a Fellow of the American Physical Society (APS). "Election to Fellowship in the American Physical Society is limited to no more than one half of one percent of the membership. Election to APS Fellowship is recognition by one's peers of significant contributions to physics." The presentation will be given at the annual APS meeting in the Division of Condensed Matter Physics (DCMP). David was nominated "for fundamental contributions and pioneering investigations in the areas of growth of doped nanocrystals and growth of photonic crystals based on self-assembly."

Congratulations, David!