Raman Installation

Recently the Ault group received our very own Raman spectrometer from Horiba Scientific. A Raman spectrometer is named after the Nobel Prize winning scientist Sir C. V. Raman. When light hits an object, some of the light is absorbed by that object (often results in that object warming up), and some of the light is scattered or reflected away. Sir Raman discovered that sometimes when light is scattered by an object, it's wavelength can slightly change (the color of light is determined by its wavelength), and that different chemical components can each change light in a consistent manner. If we shine a laser with a single, known wavelength on a sample, and measure the exact minor changes of that wavelength in the reflected light, we can determine the exact elemental composition of that sample! That is what a Raman spectrometer does (spectrometer means instrument that measures the properties of light). Pretty useful!

The Raman spectrometer is a highly sensitive piece of equipment and requires a very solid table to prevent unwanted vibrations from messing up the precise alignment of the lasers. The tables were bought separately and had to be assembled and bolted together.


Once the tables were ready, we had to carefully move the freshly unboxed Raman up on top of the table. It is quite heavy and required four people to lift  it.

 

Horiba sent us a technician to complete the installation, hook up all the wires, and teach us all how to realign the lasers, use the data collection and manipulation software, and other basic troubleshooting procedures. Our technician was the well traveled Bill, who had been installing Raman spectrometers for over the past 20 years!

 All in all, it was a busy week of heavy lifting and learning a textbooks worth of knowledge, but now its all done and we're ready to begin some experiments on our brand new Raman!

Ault Group Fall Photo!

Left to Right: Becky Craig (rotation graduate student), Amy Bondy (graduate student), Dan Gardner (graduate student), Professor Andy Ault, Hongru Shen (masters student), Raymond Chung (freshman)

SOAS (First Field Samples!)

Earlier this summer during the months of June and July, we were fortunate to get to participate in the SOAS (Southern Oxidant and Aerosol Study) field campaign in Centreville, Alabama. This field campaign was one of the largest in history, comprising hundreds of researchers from dozens of universities across the United States and around the world. These research scientists gathered to study and advance our understanding of climate change, aerosols, emissions, and the relation between natural and human-related impacts on these topics.

SEM image of aerosol particles 

Besides simply enjoying the beautiful forested region and the benefits of a peanut butter and jelly station, Dr. Andrew Ault and undergraduate Victor Nhliziyo from Tuskegee collected aerosol samples daily. After the arrival of a long-awaited freezer to store the collected samples, the aerosol samples were transported up to Ann Arbor for analysis. Using one of the single-particle techniques to analyze these micro and nano-sized aerosol samples, SEM (Scanning Electron Microscopy) (a technique used to look at really, really small stuff), our first images were captured!

Zoomed in SEM image of aerosol particles

Oxygen content

First and foremost, we were excited to see that our substrates did indeed have particles on them. Whew! It was also interesting to note the variety of particle sizes and shapes present; we definitely have our work cut out for us studying all these particles! Taking a closer look at some of the particles, we did some elemental mapping to determine their elemental composition. Besides just the pretty colors, looking at these maps can be used to determine what was floating around in the air.

Aluminum content

Carbon content

Sodium content

Vaughan Symposium

Once every year, the Department of Chemistry's graduate student council hosts the Vaughan Symposium, a department wide event in which over a hundred chemistry graduate students present posters of their research. The poster presentations are a way for students to get their projects seen by other students and professors with the hope that possible collaborations could arise. Additionally, the DOW Chemical Company sponsored the symposium and awarded over twenty $400 travel grants to the students with the best posters and presentations. Each poster was graded by two other graduate students and at least one faculty. One graduate student from each cluster (Materials, Organic, Inorganic, Analytical, Physical, and ChemBio) also gave a thirty minute talk on their research. There were several judges for the talks, and the highest graded talk won a $800 travel grant. The 2nd and 3rd placed talks each won a $400 travel grant. In total, DOW supplied over $10,000 to students this year.

Dr. Jerzy Klosin

Dr. Andrei Tokmakoff

The symposium also invited two well known chemists to give presentations on their research. The first keynote presentation early in the morning was given by Jerzy Klosin, a Dow Core R&D Fellow. Dr. Klosin discussed his research in the discovery and development of molecular catalysts for olefin polymerization with tunable reactivity toward alpha-olefins. The second, afternoon keynote speaker was Dr. Andrei Tokmakoff from the University of Chicago, whose talk was titled: Tautomerism in DNA and mechanisms of lethal mutagenesis: A study using 2D IR spectroscopy.

Dr. Victor C. Vaughan

The Vaughan Symposium is named in honor of Victor Clarence Vaughan (1851-1929), one of the first students to graduate from the University of Michigan with a Ph.D. in Chemistry. Vaughan graduated in 1876, and his dissertation is entitled "Quantitative Separation of Arsenic From Each of The Metals Precipitated by Hydrogen-Sulphide in Acid Solution." Dr. Vaughan also earned an M.D. from Michigan in 1878 and later served as dean of the Medical School from 1891-1921. He taught physiological and pathological chemistry, hygiene, bacteriology, and therapeutics at Michigan, among other subjects, and served as the president of the American Medical Association from 1914 to 1915.




Everyone in both the Ault and Pratt labs presented posters at the symposium. While no one won a travel award, everyone did a spectacular job and created much interest among the department in the research projects of the two labs. 

Daniel Gardner (L) and Dr. Andy Ault (R)

Amy Bondy (R) and Dr. Andy Ault (L)

Matt Gunsch (L) and Dr. Kerri Pratt (R)

Rosina Ho Wu (L), Jillian Cellini (C) and Eric Boone (R)

Trip to the University of Michigan Biological Station

The University of Michigan Biological Station has been operating near Pellston, Michigan since the University purchased the land in 1909. UMBS runs a series of educational and research programs during the summer, including an REU program, the Ameriflux site (CO2 flux tower), and the Prophet Tower (an ideal site for gas and aerosol measurements). Our group along with the Pratt Group in Chemistry at Michigan made the trip north on August 15-16 to learn about the site and most importantly figure out how we can be involved with such a fantastic resource! The site is near the top of the mitten in Michigan about 4 hours north of our home in Ann Arbor and one of the premier remote forest sites in the country.

View Larger Map View Larger Map

UMBS is much different than it was when Michigan purchased it. At the time most of the area had been logged to build many of the major cities in the midwest and as a result the landscape was barren and burned, a stark contrast to the extensive forests that dominate the landscape today. These forests are not primarily pine as the forests that were logged would have been, but instead have large fractions of birch and aspen, relatively fast growing trees that over took the landscape. These trees are nearing the end of their lifecycle and will be replaced over the next 30-40 years by the pine that used to dominate the region. As you can see from the different pictures this is a vast and beautiful area.

Amy Bondy is excited for a ride in ZECAV.

The Ault Group Summer 2013:
 Dan Garden (L), Andy Ault (C), Amy Bondy (R)

During our visit we had the opportunity to tour many part of the site including the FASET experiment and the canopy top using the Zero Emission Canopy Access Vehicle (ZEKAV) with Susan a student of Knute Nadelhoffer the director of UMBS. This maize and blue electric cherry picker lets researchers go to the top of the canopy to make measurements without the disrupting influence of a combustion source near by. To the right Amy Bondy gets ready to take a ride up ~30 m (100 ft) to the tree tops. Below Matt Gunsch of the Pratt group rides to the canopy top. As you can see everyone enjoyed getting to check out the top of the canopy!

Matt Gunsch of the Pratt
Group rides to the canopy
top with Susan.

One of the great parts of the visit was getting to walk around in the woods. Included is a picture of the Ault Group during a morning hike through a nearby gorge. The only hiccup was a temporarily lost cell phone, but disaster was averted and our hike got us back just in time to check out the Prophet site.

In depth discussions of where to head next with (left to right): Andy, Dan, Matt, Amy, Jillian, Eric, and Rosina.

During the second day of the visit the group was fortunate to get to climb the Prophet tower with Prof. Maryanne Carrol who has long run the site. The site is very impressive in terms of its capabilities. We all appreciated getting to climb the tower and look out over the forested landscape. It was a bit of a workout (with some head hitting for the taller folks, hardhats were huge help. Below you can see a group climbing the tower. We thank Knute, Karie, Mary Anne, and Susan for their hospitality and look forward to going back soon with some instrumentation!

One of the groups climbing the Prophet tower with Prof. Mary Anne Carroll leading the way.

Don't look down! The 100 ft tower is not a place for anyone with a fear of heights.

Welcome!

Welcome to the Ault Group Blog! 

The goal of this blog is to provide information on the research and activities of the Ault Group at the University of Michigan. The group is based out of the Department of Environmental Health Sciences (EHS) in the School of Public Health (SPH) and the Department of Chemistry in the College of Literature, Sciences and the Arts. Our group is focused on understanding the impacts of atmospheric aerosols and nanoparticles on human health and climate. Our research makes use of a wide array of instrumentation to study the aerosol health and climate effects, with a focus on single particle mass spectrometry and Raman microspectroscopy. The Ault group utilizes an integrated approach involving field measurements, laboratory measurements on field samples, and laboratory measurements of well-characterized aerosol proxies. We are just getting started so we hope you check back frequently to see what we are up!

Dr. Ault's Environmental Health Science Profile

Dr. Ault's Chemistry Profile