Volume 3 Issue 4 March 2005

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https://doi.org/10.33697/ajur.2005.001

Integrating Undergraduate Science Research: A Commentary to Undergraduate Research Faculty

https://doi.org/10.33697/ajur.2005.002

Authors and Affiliations:

Larry E. Davis, Department of Biology, College of St. Benedict-St. Johns University, Collegeville, Minnesota 56321 USA

Robert L. Eves
Department of Physical Science, Southern Utah University, Cedar City, Utah 84720 USA


On Solving Systems of ODEs Numerically

https://doi.org/10.33697/ajur.2005.003

Author(s):

Temple H. Fay, Stephan V. Joubert, and Andrew Mkolesia

Affiliation:

Department of Mathematical Technology, Tshwane University of Technology, Private Bag x680, Pretoria 0001 SOUTH AFRICA

ABSTRACT:

Many beginning courses on ordinary differential equations have a computer laboratory component in which the students are asked to solve initial value problems numerically. But little attention in texts is given to the question of how accurate such solutions are. In this article we offer a simple procedure that not only can provide a measure of accuracy, but also often produces superior numerical results.


Awareness, Partisanship and the Post-Convention Bounce: A Memory-Based Model of Post-Convention Presidential Candidate Evaluations Part II—Empirical Results

https://doi.org/10.33697/ajur.2005.004

Author(s):

Justin Grimmer

Affiliation:

Department of Mathematics and Computer Science, Wabash College, Crawfordsville, Indiana 47933

ABSTRACT:

This paper continues an analysis, begun in the December 2004 issue, that employed panel data to estimate the effects of awareness and political partisanship on post-convention candidate evaluations. The derivation of a theoretical framework was discussed in Part 1 [1]. Empirical results using data from the US presidential election of 2000 are discussed in the present article. We find that partisans of the opposite party were more resistant to the convention message of Bush than Gore, that awareness played a greater role in determining a predicted post-convention change for Gore, and that Gore’s message was received and accepted at a higher rate than Bush’s message.


Isometries, Tessellations and Escher, Oh My!

https://doi.org/10.33697/ajur.2005.005

Author(s):

Melissa Potter and Jason M. Ribando

Affiliation:

Department of Mathematics, University of Northern Iowa, Cedar Falls, Iowa 50614-0506 USA

ABSTRACT:

Motivated to better understand the wonderful artistry and hyperbolic tessellations of M.C. Escher’s Circle Limit prints, we study the isometries of the hyperbolic plane and create tessellations of the Poincaré disk using the Euclidean tools of compass and straightedge.


Self Assembly of Cyanine Dye on Clay Nanoparticles

https://doi.org/10.33697/ajur.2005.006

Author(s):

Andrew Dixon, Clint Duncan, and Hussein Samha

Affiliation:

Department of Physical Science, Southern Utah University, Cedar City, Utah 84720 USA

ABSTRACT:

The effect of Ca-montmorillonite (clay) on the aggregation behavior of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), in aqueous solutions has been investigated using UV-vis spectroscopy. The absorbance of the monomeric dye in aqueous solutions is compared with the absorbance of the aggregates formed after adding the clay. The appearance of a sharp “red-shifted” band centered at 574 nm, after the addition of clay to the aqueous solutions of the dye, indicates the formation J-aggregates on the charged surfaces of the clay particles. The spontaneous and quantitative transformation of monomers into J-aggregates was controlled by the concentration of the clay in the solution. Successive addition of clay to the dye solution causes an increase in the absorbance intensity of the J-band and consequently, a decrease in the absorbance intensity of the monomer. These changes occur linearly which suggests that the dye monomers are quantitatively being converted to J-aggregates.