Volume 8 Issue 1 June 2009

0
0

0
0
0

https://doi.org/10.33697/ajur.2009.006

EditorialAJUR Starts its 8th Year

https://doi.org/10.33697/ajur.2009.007

Author(s):

C. C. Chancey

Affiliation:

University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA


Computational Analysis of Glycerol Menthonide Using Spartan ’04

https://doi.org/10.33697/ajur.2009.008

Author(s):

Anthony Kiessling, Carissa Ganong and Ashley Johnson

Affiliation:

Mansfield University, Mansfield, Pennsylvania 16933 USA

ABSTRACT:

Glycerol menthonide has been reported in the literature and has been prepared by reaction of menthone with glycerol under acid catalysis. The menthonide was originally prepared as an additive to spearmint gum by a chemist at Wrigley’s Inc. No further chemical analysis of the menthonide has been reported in the literature. However, glycerol menthonide should be a mixture of up to 6 isomers. Spartan ‘04 was used to determine the heat of formation of each isomer in an attempt to model the reaction mixture. This information was then compared with GC/MS analysis of the product mixture. The isolation of one of the stereoisomers of glycerol menthonide is also reported.


Cyanine Dyes: Fine Structures in Their Absorption Spectra

https://doi.org/10.33697/ajur.2009.009

Author(s):

Anna Zarow and Yeung-gyo Shin

Affiliation:

Department of Chemistry/Physics, Kean University, 1000 Morris Avenue, Union, New Jersey 07083 USA

ABSTRACT:

Absorption spectra were studied for two series of 3 cyanine dyes with varying length of conjugated hydrocarbon chains. Fine structures in absorption spectra were analyzed to determine its concentration dependence as the concentration of dyes were changed from 10–8 M to 10–4 M. In all 6 dyes studied, ratios of minor peaks to the major peak remained constant within the experimental error. These results indicate that the origin of the absorption fine structure is due to the electronic coupling, an intramolecular process, rather than the aggregates formation, an intermolecular process.


Deterministic Computer Simulations of Grazing Impacts on Planetary Surfaces

https://doi.org/10.33697/ajur.2009.010

Author(s):

C.J. Massina and M. W. Roth (Department of Physics)

Paul A. Gray (Department of Computer Science)

Affiliation:

University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

ABSTRACT:

Many bodies in the solar system have features which could conceivably have been formed by a grazing impact with a comet or asteroid. We present the results of deterministic computer simulations of various objects striking a terrestrial planet at a grazing angle. The system is modeled using a combination of the Material Point Method (MPM) and classical planetary dynamics. The impact exhibits three distinct regimes: (i) the initial stage where rapid ejecta leaves the planet in a nearly straight line, (ii) the intermediate stage where the ejecta begins to curve in towards the planet and the trench is being created on the surface and the (iii) the long term stage where the trench is created and any paths exhibited by the ejecta are stable capture orbits. In the case of Mars, we show that a grazing impact can not only dig a trench which has the same general morphology as Valles Marineris but also can create ejecta which orbits the planet at distances comparable to those for current Martian satellites.