Congratulations to Daniel Gardner!

Congratulations to Daniel Gardner who officially passed his candidacy exam at the end of April!

First Field Study - Dexter, Michigan

The Ault lab has just begun its first field study! The site is located north of Dexter, Michigan, which isn't too far away from the main University of Michigan campus in Ann Arbor, but it is a good start for field work. The site is owned by the university and is currently operated by Dr. Tim Dvonch, a professor in the Environmental Health Sciences department. The site is covered in several feet of snow, but has a wooden deck raised well above the ground to keep the instruments dry. This field study involves taking a Micro-Orifice Uniform Deposit Impactor (MOUDI) out to the site and measuring the amount and composition of aerosol particles in the air. The MOUDI is placed inside an electrical box to protect it from the environment and has a hole cut out of the top to allow for the aerosol inlet to stick out.
The MOUDI works by using a pump to suck in air and pass it through a series of stages. The size of the holes from one stage to the next and the air flow rate are designed to have only particles of a particular size collide on the substrates. Anything smaller than selected will travel with the air to the next stage. The stages are also rotating - this allows for a uniform deposit of particles, and prevents large piles from forming directly underneath each orifice. On top of the MOUDI is a Cyclone, a specialized device that prevents anything larger than 10 microns from passing through. This prevents bugs or very large dust particles from clogging up all the tiny orifices. The cyclone is very heavy, and requires support or it will fall over with the MOUDI. By drilling another hole in the electrical box and setting the cyclone in the hole, we can stabilize the weight with the sturdy electrical box. The substrates are replaced twice each day for a day set and an overnight set. The substrates are placed in the fridge to prevent anything from happening between collection and analysis, and will be analyzed via SEM, TEM and Raman spectroscopy.
One of Dr. Dvonch's graduate students - Pearl Nathan - is also doing testing at the site, and provided a great deal of help in setting up the instrument. While it is extremely cold, the snowy site is a beautiful location. The study will run from Saturday, March 1st to Sunday March 9th, giving us plenty of samples to analyze and determine the composition of the air out here in Dexter.

Me (Daniel Gardner) with the MOUDI

UMBS Winter Research Meeting

February 21 and 22 brought about the third annual winter research meeting for the University of Michigan Biological Station (UMBS) hosted at the Michigan League. These meetings were created as a way for all the researchers working at the UMBS to meet others, learn about different research projects and to form new collaborations, sometimes between people who would normally not have anything in common. 
The meeting began with an introduction by the director of the station, and was followed by a hand drawn poster session. One of the biggest challenges in science is finding a way to easily and clearly communicate the research you are doing. The people in charge of the UMBS think that one way to make your research simple is to hand draw a poster in under an hour. Then over the course of the conference, people would read over the basic idea of your project on your poster and if they see something interesting, they can approach you to discuss it. This often leads to new projects and advancements in the current one.
Our current project at the UMBS is: Climate and Air Quality Impacts of Greenhouse Gases and Atmospheric Particles in Northern Michigan, and is funded by MCubed, a program that takes three professors from different departments and has them all work together. Our team includes Dr. Andy Ault from environmental health sciences (EHS), Dr. Kerri Pratt from chemistry, and Dr. Eric Kort from atmospheric, oceanic and space sciences (AOSS). Each professor brought one student/post-doc with them to the conference: Daniel Gardner (Ault), Nate May (Pratt), and Dr. Mackenzie Smith (Kort). While the three professors mingled with the other researchers, the students and post-doc took to the paper and made an artistic masterpiece.

Dr. Mackenzie Smith showing off our work of art.

After the poster session, there was a series of presentations, from a wide variety of research fields, ranging from the reproductive cycles of microscopic organisms to harvesting invasive plant life for conversion to biofuel. Once the talks were done, everyone got together and discussed potential projects for the future and who wanted to be involved in each. The big overarching project for the future was to do burn plots: highly control fires designed to burn down small sections of the forest to measure how it affects the air, soil, water, and nearby plant life, as well as to measure all aspects of the regrowth.
The group of three professors - Andy, Kerri and Eric - were the only atmospheric researchers there - the rest were mostly biologists - and several of them were interested in potential collaborations.
Overall, we learned a great deal about the biological station, the people that worked there, and the wide range of projects that can be done in the future!

Lab Renovations!

Exciting changes are happening in the Ault group as one of our labs undergoes some renovations!  We have been working hard the past week to clean up and prep the lab for the construction crew.  Most of the instruments were moved into temporary storage and out of harms way for the duration of the renovation.  Pictured to the right, the large and heavy Raman spectrometer could not be moved and was instead wrapped up and barricaded behind protective layers of tables, freezers, and boxes.  The Raman spectrometer needs to be protected from any dust, bumps, or other hazards of construction.

Above, the future site of our brand new desks and cabinets.  On the right, grad students, Hongru, Dan, Diana, and Becky, taking extra boxes and a lot of packing peanuts out to recycling during the lab cleanup.  We are very excited to be moving into our new lab space within the next couple weeks!  Be sure to check back for pictures when the renovation is complete!

Analysis at the Pacific Northwest National Lab

Analysis at the Pacific Northwest National Lab

This winter, Dr. Andrew Ault and 2nd year graduate student Amy Bondy, along with Dr. Kerri Pratt and 1st year graduate student Eric Boone, traveled across the country to visit the Pacific Northwest National Lab (PNNL). Although we experienced some flying difficulty due to the "Polar Vortex" and a frozen fuel line on our flight out of Detroit, we eventually arrived in Richland, Washington only a day late and after quite a few unexpected tours of airports out west. 

While at the national lab, we used some of the unique instrumentation available there to analyze aerosol samples collected from SOAS. With Alex Lasking as our host, and the help of his postdoc BingBing Wang, we were able to get up and running samples on the computer-controlled SEM (CCSEM) in no time! We were able to capture images, elemental maps (lots of pretty colors!), and get statistical information about the aerosols from many of the SOAS samples. With access to the lab 7 days a week, we were able to collect a ton of data! 

Although we spent almost all our time in lab, we were also able to have some fun in Richland. Cooking dinner and watching movies together in the evenings gave us a way to recharge before heading back to the lab that night. Additionally, the warm weather (up to 55 degrees) and sunshine in the "desert" of Washington was very welcome after the temperatures we left behind in Ann Arbor!

Raman Snow Analysis

Last September, two undergraduate students were fortunate to be invited to a joint project between both Prof. Andrew Ault’s and Prof. Pratt’s research groups, through the University of Michigan Undergraduate Research Opportunity Program. The project intends to establish a protocol for imaging and analyzing snow crystals for climate research, specifically the impurity concentration and distribution in Arctic snow.

We intend to use the Raman spectrometer detailed in the previous December blog post “Raman Installation” for its imaging and elemental mapping capabilities. It is an exciting prospect to be among the first in utilizing Raman on snow crystals, however, we have run into several complications. The Ault group’s Raman spectrometer features a laser filter that can control its intensity. Higher settings generally result in increasing base resolution for imaging. Unfortunately, a high filter setting is a dual-edged sword as the laser will heat up samples. In our test run with the Raman, the laser burnt through the silicon sample several times! We will most likely use a low filter setting despite the base resolution drop.  

Linkam Stage (Placeholder for lab one)

A more immediate complication is the tendency for snow to melt, especially under the Raman’s laser. We’ve made progress in the last two months in finding a way to preserve the snow crystals long enough for Raman analysis. A Linkam cooling stage is in the Ault Lab which will allow us to keep samples at a stable -30°C during imaging. 

The Lab also has a recirculating cooler which will be paired with the Linkam stage once the necessary bath fluids are ordered. Soon after, we will be ready to begin determining parameters for imaging.

Placeholder for Freezer/Snow

The Ault Group has snow that is kept in the new freezers mentioned previously in the blog. It will be used along with natural Ann Arbor snowfall until we are ready to analyze our Arctic snow currently in storage. Hopefully we will continue updating our progress as we come closer to the Undergraduate Research Symposium in April!

  

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!