By: Eric Johnson

Hello. My name is Eric and I work for Professor Smaranda Marinescu in the Chemistry Department at USC. Our group focuses on developing compounds that can be used for alternative energy purposes in order to combat global warming. One of the ways people have started trying to fight climate change is by using fuel cells instead of combustion engines in cars. Currently, fossil fuels in the form of gasoline are pumped into your car and combusted to produce energy, but the carbon dioxide emissions from this process have been leading to negative environmental side effects. Instead, fuel cells are being designed to run based on water.

In these fuel cells, hydrogen gas (H2) is used as a source of energy and water is generated throughout the reaction. Scientists have made a lot of progress on the hydrogen to energy step of this process, but using oxygen gas (O2) to make water is a much more complex issue. This process is referred to as the Oxygen Reduction Reaction (ORR) and is what I work on in my group, and the focus of my summer research as a WIES Sonosky Fellow.

The reaction is conducted in a sealed glass tube at high temperatures to form the desired catalyst

One proposed method of making ORR easier is to use catalytic materials to promote the reaction. Catalysts are materials that make the reaction easier without being consumed, so they can help perform the same reaction repeatedly over a large amount of time. In our group, we prepare catalysts for ORR in a couple of different ways. One set of catalysts are made thermally, which just means we combine all the parts in the same container and heat them to high temperatures to cause a reaction. This reaction deals with starting materials that are not very reactive with each other so they need a push from heat energy.

Top layer = ethyl acetate (“oil”), Bottom layer = water, black film in the middle = catalyst

The other material does not have this problem, and is actually too reactive. If left on their own, these materials react too rapidly and form a mess instead of the nice catalyst that we want, so we use a layering method to slow down the reaction (see the photo above). In the same way oil floats on top of water, certain chemical solvents will not mix with water. We use this principle to separate the two reacting chemicals: one chemical in water and one in the “oil”. These solutions only touch slightly, but that little bit of touching is enough to allow for a slow and controlled reaction at the interface to give us our active catalyst.

Once the catalysts are made, we can subject them to the conditions they would encounter if they were used in a fuel cell and evaluate how they hold up to leading standards. We hope to develop catalysts which can help make fuel cells a viable replacement for combustion engines both energetically and also economically. If we can do this, the impact of global warming can be lessened and we can have a cleaner, cooler world.

By: Erika Nava

I am a graduate student at California State University, Northridge working in a Fish Ecology Lab under Dr. Mark Steele. I am interested in evaluating if Marine Protected Areas (MPAs) can affect fish foraging behavior. MPAs are used to allow organisms and habitats to recover from anthropogenic impacts such as overfishing, which has significantly diminished populations of many exploited marine species. Protection provided by MPAs has allowed fish populations to recover and has increased their densities and size. But increased fish density may lead to unforeseen intraspecific competition for resources. Most studies on MPAs have focused on evaluating their performance in terms of recovery of targeted species, but few have evaluated how this protection can affect trophic interactions. Fish diet and behavior, for example, might change, and documenting such changes could improve our understanding of how MPAs affect protected species. My research intends to evaluate whether California sheephead is food limited within MPAs in southern California.

Male California sheephead at Santa Catalina Island

The foraging behavior of sheephead can influence ecosystem health. For example, previous studies showed that sheephead are capable of improving kelp forest health by controlling sea urchin (herbivore) populations.

Female sheephead searching for food

I did my research this summer at Catalina with the support of a Wrigley Institute Summer Fellowship. I started with SCUBA surveys of abundance of sheephead and invertebrates (food availability for sheephead). I also conducted time budget observations on sheephead foraging behavior. These observations will allow me to understand time spent searching for food and foraging rate within these time periods.

Sheephead foraging observations

I will also use Baited Remote Underwater Video (BRUVs) to observe fish foraging behavior, without the influence of divers. Since it can be difficult to observe diet with natural observations and impossible to control for prey availability, I will use BRUVs to introduce a standardized prey item and observe sheephead’s predation on it. By understanding if foraging interactions are changing within MPAs, my research can help inform future management strategies.