Content | Navigation |

Physics

 


Seminars

Spring 2014 Seminars

Date

Title

Author

January 20, 2014

Martin Luther King Jr. Day

January 27, 2014

A Tale of Two Colloids: Order and Disorder on a Soft Substrate.

Andrew B. Croll

February 3, 2014

Molecular Simulation of Physical Aging in Ultrathin Polymer Films

Qiyun Tang

February 10, 2014

Multiple Exciton Generation in Nanometer-sized Silicon Nanoparticles

Andrei Kryjevski

February 17, 2014

President's Day

February 24, 2014

PreAPS Blitz.

Bekele, Damith, others!

March 3, 2014

APS March Meeting

March 10, 2014

MacKenzie Steltzer

March 17, 2014

Spring Break

March 24, 2014

Determination of pK Values of Ionizable Residues in Pentapeptides and in SNase protein.

Guilherme Volpe Bossa

March 31, 2014

April 7, 2014

Following molecules out of equilibrium: From the formation of nanoparticles to the complex behavior of strongly driven systems.

Jerome Delhommelle

April 14, 2014

Coherent Raman Standoff Detection with Shaped Femtosecond Pulses

Marshall Bremer

April 21, 2014

Holiday

April 28, 2014

Answer First: Applying the heuristic-analytic theory of reasoning to examine student intuitive thinking in the context of physics

Mila Kryjevskaia

May 5, 2014

Hyperspectral Imaging: Optical System Design Considerations for an orbiting imaging Fourier Transform Spectrometer

Bruce Rafert

May 12, 2014

Excitons in Nanoscale Semiconductor Structures from the Bethe-Salpeter Equation

Deyan Mihaylov

May 19, 2014

Bacterial Adhesion on Material Surfaces

Klemen Bohinc

 

 

Excitions in Nanoscale Semiconductor Structures from the Bethe-Salpeter Equation.

Deyan Mihaylov

Department of Physics, North Dakota State University
 

Monday, May 12, 2014, 3:00-4:00pm

221 South Engineering

Deyan is a graduate student working with Andrei Kryjevski

 

Excitons are bound states of electrons and holes held together by Coulomb attraction. In semiconductor nanoparticles of size comparable to or smaller than the Exciton-Bohr radius excitons have significant effect on the density of states of the system. The standard way of calculating energies and wave functions of excitons is to solve the Bethe Salpeter equation (BSE) in the basis of Kohn-Sham (KS) orbitals and energies, the output of Density Functional Theory. In this work, we derive BSE using basic tools of many body quantum mechanics. Namely, we compute the matrix of the full, interacting Hamiltonian in the basis of electron-hole KS states, and, in particular, derive direct and exchange Coulomb terms present in the standard BSE. The method is then applied to calculating energies and wave functions of low energy excitons in a nm-sized Hydrogenated crystalline Silicon quantum dot.

Bacterial Adhesion on Material Surfaces.

Dr. Klemen Bohinc

Faculty of Health Sciences, University of Ljublijana, Slovenia
 

Monday, May 19, 2014, 3:30-4:30pm (Refreshments will be served at 3:00).

221 South Engineering

Bacterial adhesion can be controlled by different material surface characteristics like surface roughness, on which we concentrate in our study. Different glass surfaces were prepared by polishing the glass plates with different gradations. The corresponding surface roughness was controlled by atomic force microscope and profilometer.  The rate of adhered bacteria on glass surfaces was determined with spectrophotometer and scanning electron microscopy. Our results showed that the rate of adhered bacteria increases with increasing surface roughness. The increased adhesion of bacteria on more rough surfaces is the interplay between the increasing effective surface and increasing number of defects on the surface.


Student Focused. Land Grant. Research University.

Follow NDSU
  • Facebook
  • Twitter
  • RSS
  • Google Maps

Site Manager: Physics Webmaster
Published by Department of Physics

Last Updated: Friday, May 09, 2014 3:29:05 PM