Friday, February 22, 2013

Faculty Focus - John Koellner

Instructor John Koellner has been in our department part-time since 1970 which means he has been teaching here longer than all of the full-time faculty. He typically instructs some of the freshman general chemistry laboratory sections for science majors and we are very grateful for his long record of excellent service. Koellner earned three degrees from the University of Notre Dame: BS chemistry, MA teaching, and MS chemistry. 

Several years ago he retired from teaching high-school chemistry in the South Bend schools, mostly at Riley High School, after 42 years - which means he now has more time for us! Before retiring, and for a few years after, it was not uncommon for some of our freshman to have their previous high-school teacher as their current laboratory instructor. Koellner also helped out Notre Dame in their organic chemistry labs for 10 years and has supported many efforts directed to high-school chemistry such as (1) being a reader for AP chemistry exams, (2) instructing at the AP Institute at St. Mary’s College, (3) serving as the regional coordinator for Chemistry Olympiads, and (4) participating in a Howard Hughes sponsored summer research program for high school science teachers. Thanks again for all you do, Instructor Koellner. We are looking forward to many more years of your expertise in the lab.

Sunday, February 10, 2013

Research Published After Graduation

Though we experience it more often (actually constantly) than electrical or magnetic forces, gravity is the weakest of these three forces.  There are still other forces at work in nature, and faculty and students at IU South Bend are working with many other scientists from several nations to detect and learn about WIMPS - a particular type of particle that doesn't feel the stronger of these forces.  

These Weakly Interacting Massive Particles (WIMPS) are hypothetical as no one has yet detected them.  Physicists postulate that they play a role in the supposed dark matter of the our universe.  These mysterious particles are hard to detect because they have no electrical or magnetic properties and thus interact through only weaker forces, like gravity.  

Last year we announced that chemistry graduates Joshua Benkhe and Adam Grandison were both to be acknowledged in a paper for their collaborative work with the IU South Bend Department of Physics and Astromony under the supervision of physicist Ilan Levine. That work is now published as Constraints on Low-Mass WIMP Interactions on 19F from PICASSO, Physics Letters B 711 (2012) 153-161. 

More recently a paper that Joshua Benkhe actually coauthored has been published: First dark matter search results from a 4-kg CF3I bubble chamber operated in a deep underground site, Physical Review D 86, 052001 (2012). We are very proud of all our students who participate in undergraduate research and congratulate Benkhe and Grandison for their hard work. For addition information about student research in this collaborative effort between chemistry and physics please see our earlier post.

Wednesday, February 6, 2013

What runs on air but burns four times hotter than lava?

Agilent's 4100 Microwave Plasma - Atomic Emission Spectrometer, or MP-AES for short. This instrument essentially replaces our [very] old Atomic Absorption Spectrometer. Our new MP-AES is well-suited for detecting metal ions in water samples.  It first filters air into a stream of pure nitrogen and then blasts it with microwaves that transform the gas into a plasma of electrons and ions to produce something like a very hot flame. Into this plasma we send an aerosol from a water sample and the metal ions that were present in the water are excited electronically and decay to the ground state by emitting light of different wavelength. The different wavelengths indicate which metals are present in the water sample, and the intensity of the light indicates their concentration. The nitrogen generator is the white box on the floor that is fed by purified and dehydrated air (note the pipes and pressure gauges by the wall). Chemistry students will have the opportunity to use the MP-AES as early as their freshman year.

Please click here for a link to a short video presentation of the MP-AES that describes the basic ideas and engineering of the main instrument and the nitrogen generator.