Peddie EXP Summer 2018

The last two weeks of EXP went by quickly. I planned to stay at Penn until July 31 st , but since Dr. Plante gave me a new section in my project about two weeks ago I decided to stay until August 3 rd to make sure I can finish everything I needed to work on. I spent the last two weeks of my EXP experience finishing up the alkali extractions and doing data analysis. With the TOC concentrations I got from the two different extraction methods, I was able to calculate the mass of carbon extracted out of one gram of soil. Then I compared these results with the total organic carbon data Dr. Plante keeps in his lab and was able to calculate the percentage of carbon extracted. I did not finish further steps of data analysis when I left the lab, but I will be working on these data and discussing with Dr. Plante through email next week. My EXP experience overall has been wonderful. I learned much about research. I met some awesome people. I learned some life lessons both from living a...

For the first two days of last week, I finished my last batch of hot-water extraction. My data turned out well for the majority of the samples, but there were some samples that had TOC concentrations over the measuring range and one sample that had a negative number. I planned to dilute the over-range samples but had no idea what to do with the negative one. I might rerun the negative sample just to see if it's an analysis error. It is unsatisfying to see such a result, but as Dr. Dmochowski said during our lunch meeting: no progress is progress, so I hope to learn something from this negative number. Since both Kyle and I were using mid-range kits for our TOC analysis, we ran out of kits and needed to wait for more to come, and I used this time to do some data calculation. I used the total carbon amount/percentage data from Liz and calculated the percentages of TOC that were extracted by hot-water extraction. The results turned out interesting: even though there is more ...

I spent the last two weeks conducting 3 batches of hot-water extractions and testing total organic carbon concentrations on my soil samples. After spending almost two weeks consolidating my protocol, I officially began working on the soil samples from the Luquillo Critical Zone Observatory. Instead of 3 samples that I used in each of my practice trial, I have 12 samples per batch for 4 batches in total, which required much more time and attention. For my first and third batch of hot-water extractions, my data turned out well, and I could see some differences of TOC concentrations between surface and subsurface samples even though I only had half of the complete data. However, the same problem that happened in my practice trials occurred in my second batch—I got some negative numbers, which means that the TOC concentrations of certain samples are lower than that of distilled water. In order to fix this problem, Dr. Plante told me to rerun these samples after I finish all 4 batche...

The last two weeks consisted of hot-water extractions, TOC analysis, and experimental design. Initially, Dr. Plante told us to run two trials with three samples in each of our individual trials. Kyle and I would be using two different soil-to-water ratios in order to figure out which is better. I had a lot of free time in the lab when the samples were on the end-to-end shaker or were heating up for TOC analysis, so I spent the time reading some primary articles and sometimes my summer reading when I was tired. For TOC analysis of trial 1, we used mid-range kits, which allow for smaller concentrations of carbon, but it turned out that some concentrations were higher than the range of 15-150mg/L, so we decided to use high-range kits for trial 2. In trial 2, one of the sample concentrations was negative, which represented an experimental error. After discussing with Dr. Plante, we decided to add a trial 3. However, our results were not nice either. We did not use syringes for the...

I started work this past Monday, June 11 th . On the first day, I arrived at Hayden Hall, where the lab is located, a little bit earlier than Dr. Plante (My PI) did. I got into the building when he arrived, and we started working right away. He told me about a change in my project. My project is a based on the research of Liz Coward, one of Dr. Plante’s former PhD students. We planned to extract mineralized-carbon in soil samples, and then conduct thermal analysis on the residues to figure out the soil composition. However, as Dr. Plante was emailing Liz to settle on my project, Liz told him that she kept the residue samples of her extractions in the lab so that I did not have to conduct the extractions again. Dr. Plante decided that I could conduct a different kind of extraction, hot water extraction (HWE), and yield a new set of data. After everyone arrived, he introduced me to other people in the lab. Gabe is an undergrad from the University of Minnesota, and he works with...