https://doi.org/10.33697/ajur.2002.009
https://doi.org/10.33697/ajur.2002.010
Author(s):
C.C. Chancey
Affiliation:
American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA
Learning Science by Doing Science
https://doi.org/10.33697/ajur.2002.011
Author(s):
W. Franklin Gilmore
Affiliation:
Sigma Xi, The Scientific Research Society, P.O. Box 13975, 99 Alexander Drive, Research Triangle Park, North Carolina 27709 USA
Hydrologic Contaminant Transport Modeling: A Novel Analytical and Computational Approach Title
https://doi.org/10.33697/ajur.2002.012
Author(s):
C.M. Wilson, M.W. Roth, & M.Z. Iqbal
Affiliation:
University of Northern Iowa, Cedar Falls, Iowa 50614 USA
ABSTRACT:
We have developed a method for modeling contaminant transport in aquifers with rectangular boundaries utilizing an analytical solution to the porous medium flow equation and a finite difference solution to the advection-dispersion equation. Any number of wells may be placed within the aquifer, as well as any number of non-interacting contaminants. Constant head boundaries that simulate rivers may be included by means of a source term. With realistic parameters we are able to successfully model and predict contamination transport in an on campus well site used for both undergraduate pedagogy and research.
Adolescent Mothers and Internal Representational Models: Abuse, Neglect, and Romantic Relationships
https://doi.org/10.33697/ajur.2002.013
Author(s):
Sandye Ouzts and Keri Weed
Affiliation:
Department of Psychology, 471 University Parkway, University of South Carolina Aiken, Aiken, South Carolina 29801 USA
ABSTRACT:
The purpose of this study was to explore risk and protective factors associated with internal representation models of adolescent mothers. The study also looked at the role the mothers’ internal representational models play in their interaction with their romantic partners. The proposed model of abuse and neglect differentiated mothers with adequate internal models from those with abusing or neglecting models. The study was based on data analyses of self-report measures from 28 adolescent mothers from an ongoing longitudinal study. Results confirmed the hypothesis that adolescent mothers with neglecting and abusing internal models, which include a mistrust of self and others, report more depression, lower self-esteem, ineffective problem-solving approach, and pessimism. The results supported the hypothesis that mothers with a history of childhood maltreatment are more likely to have inadequate models. However, mothers who reported maltreatment as a child, but who had an effective problem-solving orientation and trusted themselves, were at less risk for child maltreatment. The results also supported the hypothesis that mothers’ internal models are associated with their romantic attachment style and their interaction with their romantic partners.
Managing Forest Road Removal Using Dynamic Programming: A Pilot Study
https://doi.org/10.33697/ajur.2002.014
Author(s):
Rebecca L. Teasley
Affiliation:
Environmental Resources Engineering, Humboldt State University, Arcata, California 95521 USA
ABSTRACT:
Since the late 1970’s the U.S. Geologic Survey (USGS) has led a program to remove abandoned logging roads in Redwood National Park. Because abandoned logging roads contribute large amounts of sediment to local fish bearing streams, the ecosystem health of these waterways suffer. Recent research has identified the effectiveness of preventing sediment from reaching the streams for different road treatments after significant storm events. However, road removal is expensive and time consuming. This research reported in this paper was part of that pilot study, and specifically reviews the feasibility of the optimization algorithm Dynamic Programming (DP), using data from recent research on road removal effectiveness. The DP sought to determine the road removal treatment that maximizes the amount of sediment saved from erosion, while meeting a budgetary constraint. The results indicate that DP is an effective tool for developing a road removal management plan. However, the order in which roads and stream crossings are treated has a large effect on the solution, indicating that the DP formulation has room for improvement. The USGS is supporting further research to reformulate the DP.
A Statistical Examination of Water Quality in Two Iowa Lakes
https://doi.org/10.33697/ajur.2002.015
Author(s):
Erin Carlson and Mark D. Ecker
Affiliation:
Department of Mathematics, University of Northern Iowa, Cedar Falls, Iowa 50614-0506 USA
ABSTRACT:
Water quality has become and important issue in the state of Iowa as well as across the entire United States. Two Iowa Lakes, Silver Lake and Casey Lake were chosen for study by a team of biologists, chemists, earth scientists and statisticians from the University of Northern Iowa. Our goals are to statistically compare the water quality in the two lakes in each year and examine whether or not each lake has changed, in terms of water quality variables, from 1999 to 2000. In addition, we explore which variables most affect phosphorus levels in each lake in 2000. Lastly, we explore the spatial distribution of phosphorus in the sediment of each lake. Discriminant Analyses and ANCOVA show significant difference between the two lakes in both 1999 and 2000 as well as a change in Silver Lake’s water quality data from 1999 to 2000. Regression Analyses show that, in Silver Lake, phosphorus levels increased during the summer of 2000 while they decreased with increasing levels of surface dissolved oxygen and decreased as the water became less clear. The analyses also show that phosphorus levels in Lake Casey decreased as the water became less clear. A significant relationship between phosphorus in the sediment and depth exists in Lake Casey. While a significant 2-dimensional spatial correlation cannot be shown in Silver Lake, spatial analyses do show the existence of a significant 3-dimensional spatial correlation in Lake Casey.