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Source Assessment Of Deposited Particles In A Slovenian Show Cave (Postojnska Jama): Evidence Of Long-Lasting Anthropogenic Impact, Gregor Muri, Aleksandra Jovičić, Andrej Mihevc Aug 2013

Source Assessment Of Deposited Particles In A Slovenian Show Cave (Postojnska Jama): Evidence Of Long-Lasting Anthropogenic Impact, Gregor Muri, Aleksandra Jovičić, Andrej Mihevc

International Journal of Speleology

Postojnska jama (Postojna Cave) is one of the most famous karst caves in the world and has been a well-known tourist attraction for nearly 200 years. It is particularly famous for its unique double-track railway. Eight heavy metals – aluminium (Al), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), strontium (Sr), and zinc (Zn) – were determined in dust deposits by ICP-MS in order to assess sources of deposited particles on the cave walls. The samples were collected along the main passage in the cave, at different horizontal and vertical levels, in order to test horizontal homogeneity and …


Diffusion Of Vitamin B12 Across A Mesoporous Metal Organic Framework, Veronica Valencia Jan 2013

Diffusion Of Vitamin B12 Across A Mesoporous Metal Organic Framework, Veronica Valencia

Undergraduate Journal of Mathematical Modeling: One + Two

We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water) at 2 different temperatures (room temperature and 37°C) by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion …


Study Of Dieldrin In Coralville Reservoir, Jeremy Smith Jan 2013

Study Of Dieldrin In Coralville Reservoir, Jeremy Smith

Undergraduate Journal of Mathematical Modeling: One + Two

Using existing experimental data taken over a period of roughly 12 years that documents the concentrations of dieldrin levels in the environment and fatty tissue of the fish, we construct a model of the total dieldrin concentration decline. Comparisons between the experimental data and speculative data can be made using calculus and elements of statistics in order to better understand the movement of dieldrin in the reservoir. Because of the potentially harmful exposure effects of dieldrin to humans as well as the environment, it is important to be able to predict when stability has been restored to the ecosystem.