Volume 6 Issue 4 March 2008

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https://doi.org/10.33697/ajur.2008.001

Visual Editorial: AJUR Authors 2002 – 2008

https://doi.org/10.33697/ajur.2008.002

Author(s):

C. C. Chancey

Affiliation:

American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA


Design and Evaluation of a Syringe Pump for Determining the Critical Micelle Concentration of Surfactants by Making Use of the Drop Volume Method

https://doi.org/10.33697/ajur.2008.003

Author(s):

Jacob Friest, Benjamin Dowse, Dru Delaet

Affiliation:

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

ABSTRACT:

Surfactants are of widespread importance in biochemistry, the detergent industry, analytical chemistry, and many other areas that are both academically and industrially important. Here we report the design and evaluation of an inexpensive and novel syringe pump. The system is suitable for the academic and small laboratory setting. It has been tested here by measuring the Critical Micelle Concentration (CMC) of surfactants with a relatively high degree of accuracy. The system may also be adapted for use in chromatography, controlled reagent dispensing for synthesis or other biochemical and biomedical applications.


Some Results on the Variation of Composite Function of Functions of Bounded d Variation

https://doi.org/10.33697/ajur.2008.004

Author(s):

Mohsen Soltanifar

Affiliation:

Department of Mathematics, Faculty of Science, K.N. Toosi University of Technology, P.O. Box 16315-1618, Tehran IRAN

ABSTRACT:

In this paper we discuss conditions under which the composite function of two functions of bounded d variation is also of bounded d variation.


Stairway to Self-Organized Criticality: SOC on a Slope using Relative Critical Heights

https://doi.org/10.33697/ajur.2008.005

Author(s):

Clinton Davis

Affiliation:

Department of Physics and Astronomy, Ohio Wesleyan University, Delaware, Ohio 43015 USA

ABSTRACT:

A computational model of loose snow avalanches was studied as an example of Self-Organized Criticality (SOC). The distribution of the magnitudes of avalanches was measured for a stair-stepped system with various critical relative differences and system slopes. Depending on the configuration, the model showed either power law behaviors or a Gaussian distribution. For configurations that displayed power laws, the slope of the power law was dependent on the configuration of the system.