March 23, 2006
review of journal articles
Hawley et al. (1986) in “The partitioning of 7beryllium in fresh water,” measure the partition coefficient of 7Be for lake sediment samples at various depths (15, 75, and 147m) in Lake Michigan. They found that Kd decreases with increasing solid concentration- although the scatter of their data is fairly large. The actual reason for the decrease in Kd with increasing solid concentration is not known (however, they do describe some explanations proposed by other authors). The authors suggest that the large scatter in their data is due to unidentified factors that affect Kd. The study did not find a correlation between Kd and the presence of inorganic carbon, organic carbon particulates, or water temperature. They also did not see a decrease in the scatter of partition coefficient when the sediments were grouped by time of year or by depth. Clay minerals may account for some of the scatter (an increase in clay minerals increases the partition coefficient), but the percentage of clay minerals present in the soil is quite small. Other factors that may affect Kd include salinity and PH.
In Li et al.’s (1984) “Partition of radiotracers between suspended particles and seawater,” the authors perform adsorption/ desorption experiments to measure the partition coefficients for multiple radiotracers as a function of equilibrium time, suspended particle concentration, and soil type. Consistent with the previous article, the authors found that the partition coefficient decreases with increasing particle concentration and reach constant values at a high particle concentration. The authors speculated but are also uncertain why Kd increases at lower suspended particle concentration. In regards to equilibrium time, it was found that most radiotracers increase with time and reach constant values within a week. The experiment also found that organic matter does not appear to have an effect on the partition coefficient.
Both of these articles are applicable to my research by delineating factors which are known to affect the partitioning of radionuclides- 7Be in particular. Also, it is important to know what factors are considered to be negligible. For example, both of the reviewed articles found that organic matter does not affect the partition coefficient. If I did not know this from reading these articles, I may have considered that to be a factor affecting Kd. Further, the second article in particular may be useful in devising a similar experimental procedure, or at least to compare my experimental setup. Although both of these articles are relatively old, I have only found a few, more recent articles in this area; this suggests that many of the uncertainties posed in these articles remain.
March 09, 2006
The general topic I am most interested in pursuing at this point is radionuclides. Professor Matisoff has delineated two projects that could potentially be done with this topic. The big picture of both of these projects is that radionuclides can be used to identify the source of sediment, quantify the amount of soil erosion, or monitor the movement of sediment in a stream. Although neither of the projects are directly linked to the aforementioned applications, they are essential for establishing and/or revising necessary parameters for such research.
The first potential project that I could do is to measure the sorption of Beryllium: how long it takes Be to travel from soil to water. I would simply measure the amount of Beryllium present in the water as a function of time under varying conditions, i.e. different soils, different concentrations, etc. The result of the experiment would be either to confirm that Beryllium adheres to the soil rapidly as presumed, or to find it does not under certain conditions.
The second potential project is to model radionuclide (Cs, Lb, and Be) profiles. This would involve using measured parameters to create a computer code. The aim is to determine what needs to be measured in the field to determine a profile.
I do not have any major concerns about doing the first project. It is a relatively simple and even tedious experiment with data that should be relatively easy to interpret. My only concern is that it might not be challenging enough- it does not require that much critical thinking. I have hesitations about the second potential project mainly because it is less straightforward and requires computer modeling! I am somewhat computer illiterate, so I need to find out if I could handle this aspect.
February 23, 2006
I met with Professors McCall and Matisoff last week. I was not all that intrigued with the potential research that Professor McCall presented. I am more interested in Professor Matisoff's research. At our meeting, we primarily discussed his radionuclide work in more detail. I think my next step is to do some research in this area to see what I would be getting myself into- before I make any decisions. And I may also be interested in Professor Saylor's research.
February 09, 2006
I am feeling better about having to make a decision about a topic for my senior project. The potential research topics that Professor Matisoff presented last week were all extremely interesting. I would like to do more research on these areas and perhaps consult with him further, after I hear from the remaining faculty. Although I initially liked the idea of developing my own research topic independently, I think it would be better for me to work with a faculty member on their area of research- especially when I know little about doing research, what experiments/techniques/equipment are available to me, etc.
February 02, 2006
I spent many hours in the library on Sunday looking through various geology journals. My only aim was to get a sense of what kind of research is being done and how it is done. In doing so, I established a narrower sense of the area of environmental geology that I might like to pursue: sustainable agriculture (soil quality, conservation techniques, etc.). However, I think it is necessary to hear from and consult with faculty about their research before I make any further decisions about potential research topics.
January 26, 2006
Future Plans and Interests in Geology
I do not have any conclusive career goals right now. Geology is a subject that I enjoy; I have not thought too far ahead about what I would like to do with it long term. I am considering geology for graduate school, or at least a related discipline of environmental studies/science. For that reason, it is extremely important to me that I thoughtfully choose a research topic- so I might obtain a better idea of research interests for graduate school and for what I would like (or not like) to do in the future.
I do know that I want to pursue some aspect of environmental geology for my senior project. This was an easy decision. Narrowing it down further will be extremely difficult. I am overwhelmed by the possibilities of topics. I have many interests within environmental geology and do not know where to begin. I want to choose the “perfect topic” (at least the perfect topic for me), but I am not sure what I like the most or even what would make a good research project.